Title of Invention	"ENGINE BLOWBY GAS PROCESSING SYSTEM"
Abstract	An engine blowby gas processing system for an engine comprising: an air cleaner (16); a carburetor (12); a breather tube (42) extending from the breather port (41) for exhausting blowby gas of the engine, said breather tube being connected to a connecting tube; an intake passage (15a) being formed within said connecting tube and connecting the carburetor and the air cleaner; an expanded portion being provided with a gas-liquid separating chamber adjacent to the intake passage, wherein an entrance joint connecting a lower part of the gas-liquid separating chamber and the breather tube are integrally formed on a first side of the connecting tube; and a blowby gas exit (36) communicating the upper portion of the gas-liquid separating chamber with the intake passage being provided in a partition between the' gas-liquid separating chamber and the intake passage.

Title of Invention

"ENGINE BLOWBY GAS PROCESSING SYSTEM"

Abstract

An engine blowby gas processing system for an engine comprising: an air cleaner (16); a carburetor (12); a breather tube (42) extending from the breather port (41) for exhausting blowby gas of the engine, said breather tube being connected to a connecting tube; an intake passage (15a) being formed within said connecting tube and connecting the carburetor and the air cleaner; an expanded portion being provided with a gas-liquid separating chamber adjacent to the intake passage, wherein an entrance joint connecting a lower part of the gas-liquid separating chamber and the breather tube are integrally formed on a first side of the connecting tube; and a blowby gas exit (36) communicating the upper portion of the gas-liquid separating chamber with the intake passage being provided in a partition between the' gas-liquid separating chamber and the intake passage.

Full Text	The present invention relates to engine blowby gas processing system The present invention relates to a system for processing blowby gas of an engine, particularly relates to the improvement of a system in which a breather tube extended from a breather port for exhausting blowby gas of an engine is connected to a connecting tube inside which an intake passage connecting a carburetor and an air cleaner is formed, blowby gas caused in a crankcase of the engine is circulated in the engine through the breather tube and the intake passage and there, a combustion process is executed. [0002] [Prior Art] Heretofore, it is already known as disclosed in Japanese published examined patent application No. 2639604 that in such an engine blowby gas processing system, an oil separator tank for separating oil included in blowby gas from the blowby gas while the blowby gas is guided into an intake passage in a connecting tube and returning the oil to the side of a crankcase of an engine is inserted on the way to a breather tube. [0003] [Problem to be Solved by the Invention] However, when the oil separator tank is inserted on the way to the breather tube as described above, a special tank is required, in addition, means for supporting the tank by the engine and the body is required to be provided, the number of parts is increased and the cost is increased. [0004] The invention is made in view of such a situation and the object is to provide an engine blowby gas processing system the configuration of which is simple and which is low-priced for enabling oil to be separated from blowby gas without inserting a special oil separator tank on the way to a breather tube. [0005] [Means to Solve the Problem] To achieve the object, the invention is based upon an engine blowby gas processing system in which a breather tube extended from a breather port for exhausting blowby gas of an engine is connected to a connecting tube inside which an intake passage connecting a carburetor and an air cleaner is formed, and is first characterized in that a swollen part provided with a gas-liquid separating chamber adjacent to the intake passage and an entrance joint connecting a lower part of the gas-liquid separating chamber to the breather tube are integrated on one side of the connecting tube and a blowby gas exit for making the upside of the gas-liquid separating chamber communicate with the intake passage is provided in a partition between the gas-liquid separating chamber and the intake passage. [0006] According to the first characteristic, blowby gas caused in a crankcase while the engine is driven flows into the gas-liquid separating chamber from the breather port via the breather tube, is separated into gas and liquid, separated oil again flows in the breather tube downward and is returned into the crankcase, blowby gas is sent from the blowby gas exit into the intake passage in the connecting tube, is inhaled into the engine, being mixed with inhaled air passing the intake passage and a combustion process is executed. [0007] In addition, as the swollen part provided with the gas-liquid separating chamber is integrated with the connecting tube, an oil separator tank is not required to be specially inserted on the way to the breather tube, therefore, means for supporting the tank is not required, the configuration can be simplified and the cost can be reduced. [0008] The invention is second characterized in addition to the first characteristic in that the air cleaner is composed of a cleaner case bonded to the upstream end of the connecting tube, an element setting plate having an opening corresponding to the intake passage and bonded to the connecting tube in the cleaner case and a cleaner element attached to the element setting plate so that the cleaner element covers the opening, the swollen part is formed on one side of the upstream end of the connecting tube and the gas-liquid separating chamber is formed by the swollen part and the element setting plate covering the open face. [0009] According to the second characteristic, the element setting plate joins the configuration of the gas-liquid separating chamber, facilitates the formation of the gas-liquid separating chamber, prevents the number of parts from being increased and can reduce the cost. [0010] Further, the invention is third characterized in addition to the first or second characteristic in that an oil return wall below the blowby gas exit and protruded on the side of the gas-liquid separating chamber is formed in the partition. [0011] According to the third characteristic, even if oil separated from blowby gas in the gas-liquid separating chamber rises along an inner wall on the side of the blowby gas exit of the gas-liquid separating chamber by the action of manifold air pressure, the oil can be prevented from entering the b-lowby gas exit by the oil return wall before the blowby gas exit. [0012] Furthermore, the invention is fourthly characterized in addition to any of the first to third characteristics in that the swollen part is formed on one side of the upside of the upstream end of the connecting tube and a battery box for housing a battery is arranged immediately under the swollen part and on the side of the connecting tube. [0013] According to the fourth characteristic, dead space immediately under the swollen part and on one side of the connecting tube is utilized for space for installing the battery box and the periphery of the engine can be compacted. [0014] [Mode for carrying out the Invention] An embodiment of the invention will be described based upon the attached drawings below. [Brief Description of the Drawings] [Fig. 1] Fig. 1 is a left side view showing a motorcycle provided with a blowby gas processing system according to the invention; [Fig. 2] Fig. 2 is an enlarged sect.ional view viewed along a line 2-2 in Fig. 1; [Fig. 3] Fig. 3 is an enlarged view showing a main part of a part shown in Fig. 2; [Fig. 4] Fig. 4 is a view viewed from a direction shown by an arrow 4 in Fig. 3; [Fig. 5] Fig. 5 is a side view showing a periphery of an air cleaner viewed from the side reverse to the side shown in Fig. 1; [Fig. 6] Fig. 6 is a sectional view viewed along a line 6-6 in Fig. 3; [Fig. 7] Fig. 7 is a sectional view viewed along a line 7-7 in Fig. 6; [Fig. 8] Fig. 8 is an end face view viewed from the upstream side of a connecting tube; [Fig. 9] Fig. 9 is an enlarged view viewed from a direction shown by an arrow 9 in Fig. 3; [Fig. 10] Fig. 10 is an enlarged view showing a main part of a part shown in Fig. 4; and [Fig. 11] Fig. 11 is a sectional view viewed along a line II-II in Fig. 9. [0015] Fig. 1 is a side view showing the left side of a motorcycle provided with a blowby gas processing system according to the invention, Fig. 2 is an enlarged sectional view viewed along a line 2-2 in Fig. 1, Fig. 3 is an enlarged view showing a main part of a part shown in Fig. 2, Fig. 4 is a view viewed from a direction shown by an arrow 4 in Fig. 3, Fig. 5 is a side view showing a peripheral part of an air cleaner viewed from the side reverse to Fig. 1, Fig. 6 is a sectional view viewed along a line 6-6 in Fig. 3, Fig. 7 is a sectional view viewed along a line 7-7 in Fig. 6, Fig. 8 is an end face view viewed from the upstream side of a connecting tube, Fig. 9 is an enlarged view viewed from a direction shown by an arrow 9 in Fig. 3, Fig. 10 is a sectional view viewed along a line 10-10 in Fig. 9 and Fig. 11 is a sectional view viewed along a line 11-11 in Fig. 9. [0016] First, as shown in Fig. 1, an engine E, a fuel tank 2 arranged on the upside of the engine E and a seat for occupants 3 ranging to the rear end of the fuel tank 2 are mounted on a body frame 1 of a motorcycle M. A front fork 5 for supporting a front wheel 4f is coupled to a head pipe Ih at the front end of the body frame 1 so that the front fork can be steered, a rear fork 6 for supporting a rear wheel 4r is coupled to a lower part of the center of the body frame 1 so that the rear fork can be vertically vibrated via a pivot 7 and a rear cushion 9 is attached between the rear fork 6 and a bracket 8 fixed to the upside of the body frame 1. The output of the engine E is transmitted to the rear wheel 4r via a chain transmission gear 10. [0017] A carburetor 12 the intake passage of which communicates with an inside intake port is attached to the rear face of a cylinder head Eh of the engine E, an exhaust pipe 13 which communicates with an inside exhaust port is attached to the front face of the cylinder head Eh and the exhaust pipe 13 is connected to an exhaust muffler 14 arranged on one side of the body frame 1. [0018] As shown in Figs. 2 to 7, an air cleaner 16 is connected to the end on the entrance side of the intake passage of the carburetor 12 via a connecting tube 15. The connecting tube 15 is made of elastic material such as rubber and a swollen part 17 the inside of which functions as a gas-liquid separating chamber 17a adjacent to an intake passage 15a in the connecting tube 15 is integrated with the upside of the upstream end. [0019] A coupling flange 18 which also surrounds the swollen part 17 is integrated with the periphery of the upstream end of the connecting tube 15. An annular groove 19 is provided to the periphery of the coupling flange 18, the end wall of a cleaner case 20 of the air cleaner 16 is fitted into the annular groove, an element setting plate 21 is overlapped on the outer end face of the coupling flange 18 and a keep plate 22 is overlapped on the inner end face of the coupling flange 18. Plural bolts 23, 23, which pierce the coupling flange 18 and the keep plate 22 are fixed to the element setting plate 21, and the coupling flange 18 and the end wall of the cleaner case 20 are held between the element setting plate 21 and the keep plate 22 by screwing nuts 24, 24, on the bolts. [0020] The element setting plate 21 is provided with an opening 25 corresponding to the intake passage 15a in the connecting tube 15, a frame trap 28 holding steel wool 26 between a pair of punched plates 27, 27' or wire nettings is installed over the opening 25 and a cleaner element 31 supported by a grid-like element holder 30 is arranged so that the cleaner element covers the frame trap 28 from the outside. [0021] The element holder 30 is provided with a strut 30a holding the cleaner element 31 from the outside, piercing the center of the cleaner element 31. In the meantime, a pair of hinge brackets 32, 32' are provided to the element setting plate 21 with the cleaner element 31 between the hinge brackets, a presser bar 33 made of a spring member for elastically pressing the head of the strut 30a on the side of the element setting plate 21 is supported by one hinge bracket 32 so that the presser bar can be turned, and a fitting ring 34 to which a hook 33a at the end of the presser bar 33 is fitted is supported by the other hinge bracket 32' . Therefore, when the hook 33a of the presser bar 33 is fitted to the fitting ring 34, the element holder 30 supporting the cleaner element 31 is fixed onto the element setting plate 21 by the spring of the presser bar 33, and when the hook 33a is detached from the fitting ring 34 and the presser bar 33 is detached from the strut 30a, it becomes possible to extract and clean the cleaner element 31. [0022] One side in a lateral direction of the cleaner case 20 is open and the open face is normally closed by a cover 43. When the cleaner element 31 is maintained, the cover 43 is detached and maintenance is performed from the open face of the cleaner case 20. [0023] As shown in Figs. 6 to 8, the gas-liquid separating chamber 17a is formed between the swollen part 17 and the element setting plate 21 covering the open end of the swollen part, and a cut-out blowby gas exist 36 for making the upside of the gas-liquid separating chamber 17a communicate with the intake passage 15a and an oil return wall 37 protruded on the side of the gas-liquid separating chamber 17a, below the blowby gas exist 36 and across the whole width in a horizontal direction of a partition 35 are formed in the partition 35 between the gas-liquid separating chamber 17a and the intake passage 15a in the connecting tube 15. An entrance joint 40 extended to a lower part of the gas-liquid separating chamber 17a is integrated with the swollen part 17 and a breather port 41 (see Fig. 1) open to the top face of the rear of a crankcase Ec of the engine E for exhausting blowby gas is connected to the entrance joint 40 via a breather tube 42. [0024] As shown in Figs. 9 to 11, an air intake 45 is provided to the upper wall of the cleaner case 20 and an intake noise-damping box 46 is normally attached to the air intake so that the intake noise-damping box can be detached. The intake noise-damping box 46 is composed of a substantially rectangular frame 4 8 made of rubber having a peripheral groove 47 into which the circumference of the air intake 45 is fitted and a passage organizer 49 made of synthetic resin connected to the inside of the frame 48 by fitting. The passage organizer 49 is provided with an outside plate 52 in which an air entrance 50 is open to one end in a longitudinal direction and an inside plate 53 which is extended downward from one end of the outside plate 52, curving and in which an air exit 51 is open to the other end, and a pair of air passages 54, 54 for connecting the air entrance 50 to the air exit 51 are formed between the outside plate 52 and the inside plate 53. [0025] A pair of couplers 55, 55 having an enormous head are integrated with the outside of the frame 48 and the coupling of the frame 48 to the cleaner case 20 is guaranteed by elastically fitting these into a pair of coupling holes 56, 56 made on the ceiling wall of the cleaner case 20. [0026] Again as shown in Figs. 3 and 5, a pair of front and rear nuts 57, 57 are attached on one side in a lateral direction of the top face of the cleaner case 20, one ear piece 58 is integrated with the top face of the cleaner case on the other side, one side of the cleaner case 20 is fixed to one side of the body frame 1 by bolts 63, 63 (see Fig. 2) screwed to the nuts 57, 57 and the ear piece 58 is connected to the other sides of the right and left body frames 1 by a bolt. Hereby, the air cleaner 16 is supported by the body frame 1. [0027] As shown in Figs. 3 and 4, the swollen part 17 forming the gas-liquid separating chamber 17a is integrated with the upside of the upstream end of the connecting tube 15 as described above and a battery box 59 made of synthetic resin for housing a battery 64 is coupled to the cleaner case 20 immediately under the swollen part 17 and on one side of the connecting tube 15. [0028] A coupling projection 60 the cross section of which is T type is integrated with the back opposite to the cleaner case 20 of the battery box 59 and is fitted to a coupling groove 61 the cross section of which is T type and which is provided to the front of the cleaner case 20 . A bracket 62 is integrated with the front of the batter box 59 and is connected to the body frame 1 by a bolt. Hereby, the battery box 59 is supported by the body frame 1 and the cleaner case 20. [0029] As a result, dead space immediately under the swollen part 17 and on one side of the connecting tube 15 is utilized for space for installing the battery box 59, the periphery of the engine E can be compacted and the supporting structure of the battery box 59 can be simplified. [0030] As shown in Figs. 1 and 3, the rear cushion 6 is arranged utilizing the dead space between the connecting tube 15 and the swollen part 17. [0031] Next, the action of the embodiment of the invention will be described. [0032] In an intake process of the engine E, after outside air that enters the air entrance 50 passes a pair of air passages 54, 54, being divided into a pair of air passages, the outside air enters the cleaner case 20 via the common air exit 51, is filtered by the cleaner element 31, passes the frame trap 28, further passes the connecting tube 15 and the carburetor 12 and is inhaled by the engine E, being mixed with jetted fuel in the carburetor 12. In the while, as intake noise caused in the air cleaner 16 is attenuated, passing a pair of air passages 54, 54 relatively narrowed, noise leaking outside can be reduced. [0033] However, in the case of a race in which the output of the engine E is regarded as important and the motorcycle M is driven, if the intake noise-damping box 46 is detached from the cleaner case 20 and outside air is directly taken in from the air intake 45 having a large opening, resistance to intake is reduced and the output of the engine can be enhanced. [0034] While the engine E is driven, blowby gas caused in the crankcase Ec flows into the gas-liquid separating chamber 17a from the breather port 41 via the breather tube 42, when the blowby gas is expanded, it is separated into gas and liquid, separated oil again flows in the breather tube 42 downward and is returned into the crankcase Ec from the breather port 41, the blowby gas from which oil is separated is sent into the intake passage 15a in the connecting tube 15 via the blowby gas exit 36, is inhaled into the engine E, being mixed with inhaled air passing the intake passage 15a and there, a combustion process is executed. [0035] Even if oil separated from blowby gas in the gas-liquid separating chamber 17a should rise along an inner wall on the side of the blowby gas exit 36 of the gas-liquid separating chamber 17a by the action of manifold air pressure, the oil can be prevented from entering the blowby gas exit 36 because the rise of the oil is prevented by the oil return wall 37 before the blowby gas exit 36. [0036] As the swollen part 17 functioning as the gas-liquid separating chamber 17a is integrated with the connecting tube 15, an oil separator tank is not required to be specially provided on the way of the breather tube 42, therefore, means for supporting the tank is not required, the configuration can be simplified and the cost can be reduced. [0037] Particularly, in case the gas-liquid separating chamber 17a is formed between the swollen part 17 integrated with one side of the upstream end of the connecting tube 15 and the element setting plate 21 covering the open end and the cut-out blowby gas exit 36 is formed in the partition 35 between the gas-liquid separating chamber 17a and the intake passage 15a in the connecting tube 15, the element setting plate 21 joins the configuration of the gas-liquid separating chamber 17a, facilitates the formation of the gas-liquid separating chamber 17a, the number of parts is prevented from being increasing and the cost can be more reduced. [0038] The invention is not limited to the embodiment and various design changes without deviating from the scope are allowed. [0039] [Effect of the Invention] As described above, according to the first characteristic of the invention, as in the engine blowby gas processing system where the breather tube extended from the breather port for exhausting blowby gas of the engine is connected to the connecting tube inside which the intake passage connecting the carburetor and the air cleaner is formed, the swollen part provided with the gas-liquid separating chamber adjacent to the intake passage and the entrance joint connecting the lower part of the gas-liquid separating chamber to the breather tube are integrated on one side of the connecting tube and the blowby gas exit for making the upside of the gas-liquid separating chamber communicate with the intake passage is provided to the partition between the gas-liquid separating chamber and the intake passage, the swollen part provided with the gas-liquid separating chamber for separating oil from blowby gas is integrated with the connecting tube, an oil separator tank is not required to be specially inserted on the way to the breather tube, therefore, means for supporting the tank is also not required, the configuration can be simplified and the cost can be reduced. [0040] According to the second characteristic of the invention, in addition to the first characteristic, as the air cleaner is composed of the cleaner case bonded to the upstream end of the connecting tube, the element setting plate provided with the opening corresponding to the intake passage and bonded to the connecting tube in the cleaner case and the cleaner element attached to the element setting plate so that the cleaner element covers the opening, the swollen part is formed on one side of the upstream end of the connecting tube and the gas-liquid separating chamber is formed by the swollen part and the element setting plate covering its open face, the element setting plate joins the configuration of the gas-liquid separating chamber, facilitates the formation of the gas-liquid separating chamber, prevents the number of parts from being increased and can more reduce the cost. [0041] Further according to the third characteristic of the invention, in addition to the first or second characteristic, as the oil return wall below the blowby gas exit and protruded on the side of the gas-liquid separating chamber is formed in the partition, the oil can be prevented from entering the blowby gas exit by the oil return wall before the blowby gas exit even if oil separated from blowby gas in the gas-liquid separating chamber rises along the inner wall on the side of the blowby gas exit of the gas-liquid separating chamber by the action of manifold air pressure. [0042] Furthermore, according to the fourth characteristic of the invention, in addition to any of the first to third characteristics, as the swollen part is formed on one side of the upside of the upstream end of the connecting tube and the battery box for housing the battery is arranged immediately under the swollen part and on the side of the connecting tube, the dead space immediately under the swollen part and on one side of the connecting tube is utilized for space for installing the battery box and the periphery of the engine can be compacted . [Description of Reference Numbers] E Engine 12 Carburetor ^5 ---Connecting tube 15a - 16 --- Air cl( Intake passage .eaner 17 - Swollen part 17a - Gas-liquid separating chamber 20 - Cleaner case 21 - Element setting plate 25 -Opening 31 - Cleaner element 35 - Partition 3 6 - Blowby gas exit 37 - Oil return wall 40 - Entrance joint 41 - Breather port 42 - Breather tube 5 9 - Battery box 64 -Battery We Claim: 1. An engine blowby gas processing system for an engine comprising: an air cleaner (16); a carburetor (12); a breather tube (42) extending from the breather port (41) for exhausting blowby gas of the engine, said breather tube being connected to a connecting tube; an intake passage (15a) being formed within said connecting tube and connecting the carburetor and the air cleaner; an expanded portion being provided with a gas-liquid separating chamber adjacent to the intake passage, wherein an entrance joint connecting a lower part of the gas-liquid separating chamber and the breather tube are integrally formed on a first side of the connecting tube; and a blowby gas exit (36) communicating the upper portion of the gas-liquid separating chamber with the intake passage being provided in a partition between the gas-liquid separating chamber and the intake passage. 2. The engine blowby gas processing system as claimed in claim 1, wherein the air cleaner (16) is composed of a cleaner case (20) joined to the upstream end of the connecting tube (15), an element setting plate (21) being provided with an opening (25) corresponding to the intake passage (15a) and joined to the connecting tube (15) in the cleaner case (20), and a cleaner element (31) attached to the element setting plate (21) so that the cleaner element covers the opening (25); the swollen part (17) is formed on one side of the upstream end of the connecting tube (15); and the gas-liquid separating chamber (17a) is formed by the swollen part (17) and the element setting plate (21) covering its open face. 3. The engine blowby gas processing system as claimed in any of claim 1 or 2, wherein an oil return wall (37) formed below the blowby gas exit (36), said oil return wall (37) protruding from a side of the gas-liquid separating chamber (17a) and being formed in said partition. 4. The engine blowby gas processing system as claimed in any of claims 1 to 3, wherein the swollen part (17) is formed on one side of the upside of the upstream end of the connecting tube (15); and a battery box (59) for housing a battery (64) is arranged immediately under the swollen part (17) and on the side of the connecting tube (15).

Full Text

The present invention relates to engine blowby gas processing system
The present invention relates to a system for processing blowby gas of an engine, particularly relates to the improvement of a system in which a breather tube extended from a breather port for exhausting blowby gas of an engine is connected to a connecting tube inside which an intake passage connecting a carburetor and an air cleaner is formed, blowby gas caused in a crankcase of the engine is circulated in the engine through the breather tube and the intake passage and
there, a combustion process is executed.
[0002]
[Prior Art]
Heretofore, it is already known as disclosed in Japanese published examined patent application No. 2639604 that in such an engine blowby gas processing system, an oil separator tank for separating oil included in blowby gas from the blowby gas while the blowby gas is guided into an intake passage in a connecting tube and returning the oil to the side of a crankcase of an engine is inserted on the way to a breather tube.
[0003]
[Problem to be Solved by the Invention]
However, when the oil separator tank is inserted on the way to the breather tube as described above, a special tank is required, in addition, means for supporting the tank by the engine and the body is required to be provided, the number of parts is increased and the cost is increased.
[0004]
The invention is made in view of such a situation and the object is to provide an engine blowby gas processing system the configuration of which is simple and which is low-priced for enabling oil to be separated from blowby gas without inserting a special oil separator tank on the way to a breather tube.
[0005]
[Means to Solve the Problem]
To achieve the object, the invention is based upon an engine blowby gas processing system in which a breather tube
extended from a breather port for exhausting blowby gas of an engine is connected to a connecting tube inside which an intake passage connecting a carburetor and an air cleaner is formed, and is first characterized in that a swollen part provided with a gas-liquid separating chamber adjacent to the intake passage and an entrance joint connecting a lower part of the gas-liquid separating chamber to the breather tube are integrated on one side of the connecting tube and a blowby gas exit for making the upside of the gas-liquid separating chamber communicate with the intake passage is provided in a partition between the gas-liquid separating chamber and the intake passage. [0006]
According to the first characteristic, blowby gas caused in a crankcase while the engine is driven flows into the gas-liquid separating chamber from the breather port via the breather tube, is separated into gas and liquid, separated oil again flows in the breather tube downward and is returned into the crankcase, blowby gas is sent from the blowby gas exit into the intake passage in the connecting tube, is inhaled into the engine, being mixed with inhaled air passing the intake passage and a combustion process is executed. [0007]
In addition, as the swollen part provided with the gas-liquid separating chamber is integrated with the connecting tube, an oil separator tank is not required to be specially inserted on the way to the breather tube, therefore, means for supporting the tank is not required, the configuration can be simplified and the cost can be reduced.
[0008]
The invention is second characterized in addition to the first characteristic in that the air cleaner is composed of a cleaner case bonded to the upstream end of the connecting tube, an element setting plate having an opening corresponding to the intake passage and bonded to the connecting tube in the cleaner case and a cleaner element attached to the element setting plate so that the cleaner element covers the opening, the swollen part is formed on one side of the upstream end of the connecting tube and the gas-liquid separating chamber is formed by the swollen part and the element setting plate covering the open face. [0009]
According to the second characteristic, the element setting plate joins the configuration of the gas-liquid separating chamber, facilitates the formation of the gas-liquid separating chamber, prevents the number of parts from being increased and can reduce the cost. [0010]
Further, the invention is third characterized in addition to the first or second characteristic in that an oil return wall below the blowby gas exit and protruded on the side of the gas-liquid separating chamber is formed in the partition. [0011]
According to the third characteristic, even if oil separated from blowby gas in the gas-liquid separating chamber rises along an inner wall on the side of the blowby gas exit
of the gas-liquid separating chamber by the action of manifold air pressure, the oil can be prevented from entering the b-lowby gas exit by the oil return wall before the blowby gas exit. [0012]
Furthermore, the invention is fourthly characterized in addition to any of the first to third characteristics in that the swollen part is formed on one side of the upside of the upstream end of the connecting tube and a battery box for housing a battery is arranged immediately under the swollen part and on the side of the connecting tube. [0013]
According to the fourth characteristic, dead space immediately under the swollen part and on one side of the connecting tube is utilized for space for installing the battery box and the periphery of the engine can be compacted. [0014] [Mode for carrying out the Invention]
An embodiment of the invention will be described based upon the attached drawings below.

[Brief Description of the Drawings] [Fig. 1]
Fig. 1 is a left side view showing a motorcycle provided with a blowby gas processing system according to the invention; [Fig. 2]
Fig. 2 is an enlarged sect.ional view viewed along a line 2-2 in Fig. 1; [Fig. 3]
Fig. 3 is an enlarged view showing a main part of a part shown in Fig. 2; [Fig. 4]
Fig. 4 is a view viewed from a direction shown by an arrow 4 in Fig. 3; [Fig. 5]
Fig. 5 is a side view showing a periphery of an air cleaner viewed from the side reverse to the side shown in Fig. 1; [Fig. 6]
Fig. 6 is a sectional view viewed along a line 6-6 in Fig. 3; [Fig. 7]
Fig. 7 is a sectional view viewed along a line 7-7 in Fig. 6; [Fig. 8]
Fig. 8 is an end face view viewed from the upstream side of a connecting tube; [Fig. 9]
Fig. 9 is an enlarged view viewed from a direction shown by an arrow 9 in Fig. 3; [Fig. 10]
Fig. 10 is an enlarged view showing a main part of a part shown in Fig. 4; and [Fig. 11]
Fig. 11 is a sectional view viewed along a line II-II in Fig. 9. [0015]
Fig. 1 is a side view showing the left side of a motorcycle provided with a blowby gas processing system according to the invention, Fig. 2 is an enlarged sectional view viewed along a line 2-2 in Fig. 1, Fig. 3 is an enlarged view showing a main part of a part shown in Fig. 2, Fig. 4 is a view viewed from a direction shown by an arrow 4 in Fig. 3, Fig. 5 is a side view showing a peripheral part of an air cleaner viewed from the side reverse to Fig. 1, Fig. 6 is a sectional view viewed
along a line 6-6 in Fig. 3, Fig. 7 is a sectional view viewed along a line 7-7 in Fig. 6, Fig. 8 is an end face view viewed from the upstream side of a connecting tube, Fig. 9 is an enlarged view viewed from a direction shown by an arrow 9 in Fig. 3, Fig. 10 is a sectional view viewed along a line 10-10 in Fig. 9 and Fig. 11 is a sectional view viewed along a line 11-11 in Fig. 9. [0016]
First, as shown in Fig. 1, an engine E, a fuel tank 2 arranged on the upside of the engine E and a seat for occupants 3 ranging to the rear end of the fuel tank 2 are mounted on a body frame 1 of a motorcycle M. A front fork 5 for supporting a front wheel 4f is coupled to a head pipe Ih at the front end of the body frame 1 so that the front fork can be steered, a rear fork 6 for supporting a rear wheel 4r is coupled to a lower part of the center of the body frame 1 so that the rear fork can be vertically vibrated via a pivot 7 and a rear cushion 9 is attached between the rear fork 6 and a bracket 8 fixed to the upside of the body frame 1. The output of the engine E is transmitted to the rear wheel 4r via a chain transmission gear 10. [0017]
A carburetor 12 the intake passage of which communicates with an inside intake port is attached to the rear face of a cylinder head Eh of the engine E, an exhaust pipe 13 which communicates with an inside exhaust port is attached to the front face of the cylinder head Eh and the exhaust pipe 13 is connected to an exhaust muffler 14 arranged on one side of the
body frame 1. [0018]
As shown in Figs. 2 to 7, an air cleaner 16 is connected to the end on the entrance side of the intake passage of the carburetor 12 via a connecting tube 15. The connecting tube 15 is made of elastic material such as rubber and a swollen part 17 the inside of which functions as a gas-liquid separating chamber 17a adjacent to an intake passage 15a in the connecting tube 15 is integrated with the upside of the upstream end. [0019]
A coupling flange 18 which also surrounds the swollen part 17 is integrated with the periphery of the upstream end of the connecting tube 15. An annular groove 19 is provided to the periphery of the coupling flange 18, the end wall of a cleaner case 20 of the air cleaner 16 is fitted into the annular groove, an element setting plate 21 is overlapped on the outer end face of the coupling flange 18 and a keep plate 22 is overlapped on the inner end face of the coupling flange 18.
Plural bolts 23, 23, which pierce the coupling flange 18
and the keep plate 22 are fixed to the element setting plate 21, and the coupling flange 18 and the end wall of the cleaner case 20 are held between the element setting plate 21 and the
keep plate 22 by screwing nuts 24, 24, on the bolts.
[0020]
The element setting plate 21 is provided with an opening 25 corresponding to the intake passage 15a in the connecting tube 15, a frame trap 28 holding steel wool 26 between a pair of punched plates 27, 27' or wire nettings is installed over
the opening 25 and a cleaner element 31 supported by a grid-like element holder 30 is arranged so that the cleaner element covers the frame trap 28 from the outside. [0021]
The element holder 30 is provided with a strut 30a holding the cleaner element 31 from the outside, piercing the center of the cleaner element 31. In the meantime, a pair of hinge brackets 32, 32' are provided to the element setting plate 21 with the cleaner element 31 between the hinge brackets, a presser bar 33 made of a spring member for elastically pressing the head of the strut 30a on the side of the element setting plate 21 is supported by one hinge bracket 32 so that the presser bar can be turned, and a fitting ring 34 to which a hook 33a at the end of the presser bar 33 is fitted is supported by the other hinge bracket 32' . Therefore, when the hook 33a of the presser bar 33 is fitted to the fitting ring 34, the element holder 30 supporting the cleaner element 31 is fixed onto the element setting plate 21 by the spring of the presser bar 33, and when the hook 33a is detached from the fitting ring 34 and the presser bar 33 is detached from the strut 30a, it becomes possible to extract and clean the cleaner element 31. [0022]
One side in a lateral direction of the cleaner case 20 is open and the open face is normally closed by a cover 43. When the cleaner element 31 is maintained, the cover 43 is detached and maintenance is performed from the open face of the cleaner case 20. [0023]

As shown in Figs. 6 to 8, the gas-liquid separating chamber 17a is formed between the swollen part 17 and the element setting plate 21 covering the open end of the swollen part, and a cut-out blowby gas exist 36 for making the upside of the gas-liquid separating chamber 17a communicate with the intake passage 15a and an oil return wall 37 protruded on the side of the gas-liquid separating chamber 17a, below the blowby gas exist 36 and across the whole width in a horizontal direction of a partition 35 are formed in the partition 35 between the gas-liquid separating chamber 17a and the intake passage 15a in the connecting tube 15. An entrance joint 40 extended to a lower part of the gas-liquid separating chamber 17a is integrated with the swollen part 17 and a breather port 41 (see Fig. 1) open to the top face of the rear of a crankcase Ec of the engine E for exhausting blowby gas is connected to the entrance joint 40 via a breather tube 42. [0024]
As shown in Figs. 9 to 11, an air intake 45 is provided to the upper wall of the cleaner case 20 and an intake noise-damping box 46 is normally attached to the air intake so that the intake noise-damping box can be detached. The intake noise-damping box 46 is composed of a substantially rectangular frame 4 8 made of rubber having a peripheral groove 47 into which the circumference of the air intake 45 is fitted and a passage organizer 49 made of synthetic resin connected to the inside of the frame 48 by fitting. The passage organizer
49 is provided with an outside plate 52 in which an air entrance
50 is open to one end in a longitudinal direction and an inside
plate 53 which is extended downward from one end of the outside plate 52, curving and in which an air exit 51 is open to the other end, and a pair of air passages 54, 54 for connecting the air entrance 50 to the air exit 51 are formed between the outside plate 52 and the inside plate 53. [0025]
A pair of couplers 55, 55 having an enormous head are integrated with the outside of the frame 48 and the coupling of the frame 48 to the cleaner case 20 is guaranteed by elastically fitting these into a pair of coupling holes 56, 56 made on the ceiling wall of the cleaner case 20. [0026]
Again as shown in Figs. 3 and 5, a pair of front and rear nuts 57, 57 are attached on one side in a lateral direction of the top face of the cleaner case 20, one ear piece 58 is integrated with the top face of the cleaner case on the other side, one side of the cleaner case 20 is fixed to one side of the body frame 1 by bolts 63, 63 (see Fig. 2) screwed to the nuts 57, 57 and the ear piece 58 is connected to the other sides of the right and left body frames 1 by a bolt. Hereby, the air cleaner 16 is supported by the body frame 1. [0027]
As shown in Figs. 3 and 4, the swollen part 17 forming the gas-liquid separating chamber 17a is integrated with the upside of the upstream end of the connecting tube 15 as described above and a battery box 59 made of synthetic resin for housing a battery 64 is coupled to the cleaner case 20 immediately under the swollen part 17 and on one side of the connecting tube 15.
[0028]
A coupling projection 60 the cross section of which is T type is integrated with the back opposite to the cleaner case 20 of the battery box 59 and is fitted to a coupling groove 61 the cross section of which is T type and which is provided to the front of the cleaner case 20 . A bracket 62 is integrated with the front of the batter box 59 and is connected to the body frame 1 by a bolt. Hereby, the battery box 59 is supported by the body frame 1 and the cleaner case 20. [0029]
As a result, dead space immediately under the swollen part 17 and on one side of the connecting tube 15 is utilized for space for installing the battery box 59, the periphery of the engine E can be compacted and the supporting structure of the battery box 59 can be simplified. [0030]
As shown in Figs. 1 and 3, the rear cushion 6 is arranged utilizing the dead space between the connecting tube 15 and the swollen part 17. [0031]
Next, the action of the embodiment of the invention will be described. [0032]
In an intake process of the engine E, after outside air that enters the air entrance 50 passes a pair of air passages 54, 54, being divided into a pair of air passages, the outside air enters the cleaner case 20 via the common air exit 51, is filtered by the cleaner element 31, passes the frame trap 28,
further passes the connecting tube 15 and the carburetor 12 and is inhaled by the engine E, being mixed with jetted fuel in the carburetor 12. In the while, as intake noise caused in the air cleaner 16 is attenuated, passing a pair of air passages 54, 54 relatively narrowed, noise leaking outside can be reduced. [0033]
However, in the case of a race in which the output of the engine E is regarded as important and the motorcycle M is driven, if the intake noise-damping box 46 is detached from the cleaner case 20 and outside air is directly taken in from the air intake 45 having a large opening, resistance to intake is reduced and the output of the engine can be enhanced. [0034]
While the engine E is driven, blowby gas caused in the crankcase Ec flows into the gas-liquid separating chamber 17a from the breather port 41 via the breather tube 42, when the blowby gas is expanded, it is separated into gas and liquid, separated oil again flows in the breather tube 42 downward and is returned into the crankcase Ec from the breather port 41, the blowby gas from which oil is separated is sent into the intake passage 15a in the connecting tube 15 via the blowby gas exit 36, is inhaled into the engine E, being mixed with inhaled air passing the intake passage 15a and there, a combustion process is executed. [0035]
Even if oil separated from blowby gas in the gas-liquid separating chamber 17a should rise along an inner wall on the
side of the blowby gas exit 36 of the gas-liquid separating chamber 17a by the action of manifold air pressure, the oil can be prevented from entering the blowby gas exit 36 because the rise of the oil is prevented by the oil return wall 37 before the blowby gas exit 36. [0036]
As the swollen part 17 functioning as the gas-liquid separating chamber 17a is integrated with the connecting tube 15, an oil separator tank is not required to be specially provided on the way of the breather tube 42, therefore, means for supporting the tank is not required, the configuration can be simplified and the cost can be reduced. [0037]
Particularly, in case the gas-liquid separating chamber 17a is formed between the swollen part 17 integrated with one side of the upstream end of the connecting tube 15 and the element setting plate 21 covering the open end and the cut-out blowby gas exit 36 is formed in the partition 35 between the gas-liquid separating chamber 17a and the intake passage 15a in the connecting tube 15, the element setting plate 21 joins the configuration of the gas-liquid separating chamber 17a, facilitates the formation of the gas-liquid separating chamber 17a, the number of parts is prevented from being increasing and the cost can be more reduced. [0038]
The invention is not limited to the embodiment and various design changes without deviating from the scope are allowed. [0039]
[Effect of the Invention]
As described above, according to the first characteristic of the invention, as in the engine blowby gas processing system where the breather tube extended from the breather port for exhausting blowby gas of the engine is connected to the connecting tube inside which the intake passage connecting the carburetor and the air cleaner is formed, the swollen part provided with the gas-liquid separating chamber adjacent to the intake passage and the entrance joint connecting the lower part of the gas-liquid separating chamber to the breather tube are integrated on one side of the connecting tube and the blowby gas exit for making the upside of the gas-liquid separating chamber communicate with the intake passage is provided to the partition between the gas-liquid separating chamber and the intake passage, the swollen part provided with the gas-liquid separating chamber for separating oil from blowby gas is integrated with the connecting tube, an oil separator tank is not required to be specially inserted on the way to the breather tube, therefore, means for supporting the tank is also not required, the configuration can be simplified and the cost can be reduced. [0040]
According to the second characteristic of the invention, in addition to the first characteristic, as the air cleaner is composed of the cleaner case bonded to the upstream end of the connecting tube, the element setting plate provided with the opening corresponding to the intake passage and bonded to the connecting tube in the cleaner case and the cleaner element
attached to the element setting plate so that the cleaner element covers the opening, the swollen part is formed on one side of the upstream end of the connecting tube and the gas-liquid separating chamber is formed by the swollen part and the element setting plate covering its open face, the element setting plate joins the configuration of the gas-liquid separating chamber, facilitates the formation of the gas-liquid separating chamber, prevents the number of parts from being increased and can more reduce the cost. [0041]
Further according to the third characteristic of the invention, in addition to the first or second characteristic, as the oil return wall below the blowby gas exit and protruded on the side of the gas-liquid separating chamber is formed in the partition, the oil can be prevented from entering the blowby gas exit by the oil return wall before the blowby gas exit even if oil separated from blowby gas in the gas-liquid separating chamber rises along the inner wall on the side of the blowby gas exit of the gas-liquid separating chamber by the action of manifold air pressure. [0042]
Furthermore, according to the fourth characteristic of the invention, in addition to any of the first to third characteristics, as the swollen part is formed on one side of the upside of the upstream end of the connecting tube and the battery box for housing the battery is arranged immediately under the swollen part and on the side of the connecting tube, the dead space immediately under the swollen part and on one
side of the connecting tube is utilized for space for installing the battery box and the periphery of the engine can be compacted . [Description of Reference Numbers]

E Engine
12 Carburetor
^5 ---Connecting tube 15a -
16 --- Air cl(
Intake passage .eaner
17 - Swollen part
17a - Gas-liquid separating chamber
20 - Cleaner case
21 - Element setting plate
25 -Opening
31 - Cleaner element
35 - Partition
3 6 - Blowby gas exit
37 - Oil return wall
40 - Entrance joint
41 - Breather port
42 - Breather tube
5 9 - Battery box
64 -Battery

We Claim:
1. An engine blowby gas processing system for an engine comprising:
an air cleaner (16);
a carburetor (12);
a breather tube (42) extending from the breather port (41) for exhausting blowby gas of the
engine, said breather tube being connected to a connecting tube;
an intake passage (15a) being formed within said connecting tube and connecting the carburetor
and the air cleaner; an expanded portion being provided with a gas-liquid separating chamber
adjacent to the intake passage,
wherein an entrance joint connecting a lower part of the gas-liquid separating chamber and the
breather tube are integrally formed on a first side of the connecting tube; and
a blowby gas exit (36) communicating the upper portion of the gas-liquid separating chamber
with the intake passage being provided in a partition between the gas-liquid separating chamber
and the intake passage.
2. The engine blowby gas processing system as claimed in claim 1, wherein the air cleaner (16) is composed of a cleaner case (20) joined to the upstream end of the connecting tube (15), an element setting plate (21) being provided with an opening (25) corresponding to the intake passage (15a) and joined to the connecting tube (15) in the cleaner case (20), and a cleaner element (31) attached to the element setting plate (21) so that the cleaner element covers the opening (25); the swollen part (17) is formed on one side of the upstream end of the connecting tube (15); and the gas-liquid separating chamber (17a) is formed by the swollen part (17) and the element setting plate (21) covering its open face.
3. The engine blowby gas processing system as claimed in any of claim 1 or 2, wherein an oil return wall (37) formed below the blowby gas exit (36), said oil return wall (37) protruding from a side of the gas-liquid separating chamber (17a) and being formed in said partition.
4. The engine blowby gas processing system as claimed in any of claims 1 to 3, wherein the swollen part (17) is formed on one side of the upside of the upstream end of the connecting tube
(15); and a battery box (59) for housing a battery (64) is arranged immediately under the swollen part (17) and on the side of the connecting tube (15).

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Patent Number

252428

Indian Patent Application Number

329/DEL/2003

PG Journal Number

20/2012

Publication Date

18-May-2012

Grant Date

15-May-2012

Date of Filing

21-Mar-2003

Name of Patentee

HONDA GIKEN KOGYO KABUSHIKI KAISHA

Applicant Address

1-1, MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO, JAPAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	HISAKAZU YASUI	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.

PCT International Classification Number

C03B 9/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2002-167621	2002-06-07	Japan