Title of Invention

"CHAIN CASE FOR MOTORCYCLE"

Abstract [Solving Means] A full cover type chain case 3 is vertically divided into an upper case 4 and a lower case 5 each of which is made of a resin, with respect to mating portions of the upper and lower cases, the outer side walls of the intermediate portions have forked portions 34, 44 into which intermediate insertion plates 23 provided on arm pipes 13a of a rear swing arm 2 are to be inserted, and the inner walls of the intermediate portions have an engagement portion including an engagement hole and an engagement claw 45. The rear end portions of the upper and lower cases are floatingly supported by screwing stepped bolts 63 passing through slots 36, 46 via ring rubber members 62 in threaded holes 25, 26 of the end piece 17.
Full Text The present invention relates to a chain case for a motorcycle.
Chain cases for covering a chain of a motorcycle have been known, for example, from Japanese Patent Publication No. Hei 6-6438. A chain case disclosed in this |document is made from aluminum and is divided into two ! parts in the width direction of a vehicular body.
The above chain case is of a full cover type covering the entire chain. Differently from such a full cover type, a half cover type covering the upper half of a chain is known, and in this case, the chain case is made from a resin.
[Problem to be Solved by the Invention]
A chain case made of a metal requires a large number of components and a large number of manufacturing steps including pressing, welding and painting.
The chain case made from a metal is relatively
heavy in weight, being limited in mounting structure, and
it cannot absorb contact noise occurring due to contact
between the excessively elongated chain and the inner
surface of the chain case.
A chain case made of a resin can solve much of these problems; however, it cannot be practically used as a full cover type for the following reasons:
{ 1 ) Divided parts of the chain case are difficult to be mated to each other due to a large deviation due to a molding error and /or a thermal expansion.
(2) There is a possibility in stress concentration at a
mounting portion due to a difference in thermal expansion
coefficient between the resin made chain case and a metal
made rear swing arm to which the chain case is mounted.
(3) The resin made chain case is liable to be damaged
due to interference with an excessively elongated chain.
[Means for Solving the Problem]
To solve the above problems , according to the present invention, there is provided a chain case for a motorcycle, supported by a rear swing arm swingably supported by a vehicular body and covering a chain longitudinally extending over and under the rear swing arm, characterized in that the chain case is of a full cover type in which the chain case is divided into an upper case and a lower case and substantially covers the entire ch.ain when the upper and lower cases are mated to each other in
the vertical direction; each of the upper and lower cases is made from a resin; and an engagement mechanism for restricting vertical movements of the upper and lower cases is provided at intermediate mating portions of the upper and lower cases.
In this case, preferably, at least one of mounting portions to the rear swing arm at rear portions of the upper and lower cases has a floating structure, or each of the upper and lower cases includes an intermediate outer wall fixed by insertion to an upward or downward projecting member provided on the rear swing arm.
The lower case, preferably, has on an inner surface thereof a reinforcing member provided at a position under a chain line. The reinforcing member may be made from a metal or an elastic material.
The chain case, preferably, has on a side surface thereof a view window for checking elongation of the chain.
[Effect of the invention]
In a full cover type resin made chain case divided into upper and lower cases according to the present
invention, the upper and lower cases can be easily mated to each other even when there is a relatively large deviation due to a molding error and/or a thermal expansion by provision of an engagement mechanism for restricting vertical movements of the upper and lower cases at intermediate mating portions of the upper and lower cases.
Since at least one of mounting portions to a rear swing arm has a floating structure, it is possible to absorb a difference in thermal expansion between the metal made rear swing arm and the resin made chain case, and hence to avoid stress concentration at the mounting portions
Each intermediate outer side wall of the upper and lower cases , which is fixed by insertion to an upward or downward projecting member provided on the rear swing arm, is hard to be deformed due to thermal expansion.
Since the excessively elongated chain is brought in contact with a reinforcing member provided in the lower case at a position under the chain line, the resin made chain case is prevented from being damaged due to interference with the chain.
If the reinforcing member is made from a metal, it functions as a sound plate capable of generating contact sound when being brought in contact with the elongated chain. This is effective to rapidly check the excessive elongation of the chain on the basis of the contact sound.
If the reinforcing member is made from an elastic material, it can absorb an impact due to interference with the excessively elongated chain, and also it prevents occurrence of the contact noise.
The provision of the view window on the side surface of the chain case makes it possible to simply check the excessive elongation of the chain and to certainly adjust the chain. This is effective to relatively prevent the interference of the chain even when the reinforcing member is omitted, and to more certainly prevent interference with the chain when the reinforcing member is provided.
Accordingly, the present invention relates to a chain case for a
motorcycle, supported by a rear swing arm swingably supported by a
vehicular body and covering a chain longitudinally extending over and
under said rear swing arm, characterized in that said chain case is of a full cover type in which said chain case is divided into an upper case and a lower case and substantially covers the entire chain when said upper and lower cases are mated to each other in the vertical direction;
each of said upper and lower cases is made from a resin; and an engagement mechanism for restricting vertical movements of said upper and lower cases is provided at intermediate mating portions of said upper and lower cases.
[Fig. 1]
A perspective view of a chain case, showing a state in which the chain case is mounted to a rear swing arm.
[Fig. 2]
A side view of a front end portion of the chain case when the chain case is mounted to a vehicular body. [Figs. 3(A) and 3(B)]
A side view and a bottom view of an upper case of the chain case, respectively. [Figs. 4(A) and 4(C)]
A side view and a plan view of a lower case of the chain case, respectively. [Fig. 5]
A sectional view taken on line 5-5 of Fig. 1, showing a state in which a portion shown by line 5-5 of the chain case is mounted to the rear swing arm. [Fig. 6]
A sectional view taken on line 6-6 of Fig. 1, showing a state in which a portion shown by line 6-6 of the chain case is mounted to the rear swing arm. [Fig. 7]
A sectional view taken on line 7-7 of Fig. 1, showing a state in which a portion shown by line 7-7 of the chain case is mounted to the rear swing arm. [Fig. 8]
A sectional view taken on line 8-8 of Fig. 1, showing a state in which a portion shown by line 8-8 of the chain case is mounted to the rear swing arm. [Fig. 9]
A sectional view taken on line 9-9 of Fig. 1, showing a state in which a portion shown by line 9-9 of the
chain case is mounted to the rear swing arm. [Fig. 10]
A view showing a modification of the mounting portion. [Fig. 11]
A view showing a modification of the reinforcing member.
[Preferred Embodiment of the Invention]
One embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a
perspective view of a chain case, showing a state in which the chain case is mounted to a rear swing arm; Fig. 2 is a side view of a front end portion of the chain case when the chain case is mounted to a vehicular body; Figs. 3 (A) and 3(B) are a side view and a bottom view of an upper case of the chain case, respectively; Figs. 4 (A) and 4(C) are a side view and a plan view of a lower case of the chain case, respectively; Figs. 5 to 9 are sectional views of the chain case shown in Fig. 1, showing a state in which the chain case is mounted to the rear swing arm, wherein Fig. 5 is a sectional view taken on line 5-5 of Fig. 1; Fig. 6 is a sectional view taken on line 6-6 of Fig. 1; Fig. 7 is a sectional view taken on line 7-7 of Fig. 1; Fig. 8 is a sectional view taken on line 8-8 of Fig. 1; and Fig. 9 is a sectional view taken on line 9-9 of Fig. 1; Fig. 10 is a view showing a modification of a mounting portion of the chain case; and Fig. 11 is a view showing a modification of a reinforcing member of the chain case.
As shown in Fig. 2, a leading end of a rear swing arm 2 is swingably supported on a vertically extending pivot frame 1. A chain case 3 is mounted to the rear swing
:
arm 2 in such a manner as to be swingable integrally therewith .
The chain case 3 is made from a suitable resin such as polypropylene, and it is vertically divided into an upper case 4 and a lower case 5.
A front end portion of the chain case 3 extends to a portion near a drive sprocket 7 provided on a transmission 6 of an engine, and is covered with a sprocket cover 8.
A chain 10 is wound around the drive sprocket 7 and a driven sprocket 9 supported on a rear end of the rear swing arm 2.
The chain 10 is composed of an upper chain line 11 and a lower chain line 12 which pass over and under the rear swing arm 2, respectively.
As seen from Fig. 1, the rear swing arm 2 includes a pair of right and left arm pipes 13a, 13b connected to each other at front ends thereof by means of a cross member 14. In the arm pipes 13a, 13b, bearings 15, 16 are mounted at the front ends thereof respectively, and also end pieces 17, 18 are mounted at rear ends thereof respectively.
Each of the end pieces 17, 18 has a slot 19 for supporting an axle of a rear wheel. [0027]
The left arm pipe 13a extends in the longitudinal direction between the upper and lower chain lines 11 and 12 of the chain 10 in a side view, to which the chain case 3 is mounted.
In the cross member 14, front insertion plates 20, which are to be positioned inside (on the body center side; the same shall apply hereinafter) the chain case 3 upon assembly, are upward and downward projectingly provided in the vicinity of the arm pipe 13a, and a chain slider 21 made from a resin or the like, which is to be positioned under the chain 10 upon assembly, is mounted outside the front insertion plates 20.
A mounting stay 22 is mounted on each of the upper and lower surfaces of a left side end portion in such a manner as to extend from each of the front insertion plates 20 onto the arm pipe 13a and to be bent thereat upward or downward. [0030]
Each of the upper and lower mounting stays 22 has at its leading end portion a through-hole 22a provided with a weld nut 22b on the inner surface side of the mounting stay 22.
The arm pipe 13a has intermediate insertion plates 23 upward and downward projecting from an intermediate portion thereof.
The end piece 17 has a threaded hole 25 over a slot 19 and a threaded hole 26 at a leading end of a downward projecting stay 24. ['•00 33]'
As seen from Figs. 1 and Figs. 3 (A) and 3(B), the upper case 4 formed in a substantially squared U-shape opened downward in cross-section has a fitting stepped portion 30 projecting forward from its leading end; and a projecting side portion 31, which is to project forward of the cross member 14 upon assembly, provided projectingly downward from a lower end of an inner side wall of the upper case 4.
In the upper case 4, an outer side wall has a through-hole 32 on its side surface corresponding to the
mounting stay 22, and the inner side wall has at a position corresponding to the through-hole 32 a forked potion 33 into which the upper insertion plate 20 is to be fitted upon assembly (see Fig. 5).
The outer side wall of the upper case 4 has at a position corresponding to the upper intermediate insertion plate 23 a forked portion 34 which is an insertion groove receiving the upper intermediate insertion plate 23 and which is formed of a rib 34a projecting downward, inward from the outer side wall and the inner surface of the outer side wall, and the inner side wall of the upper case 4 has an engagement hole 35 (see Fig. 7).
The outer side wall of the upper case 4 has a slot 36 at a position corresponding to the threaded hole 26 of the end piece 17 provided at the rear portion of the left arm pipe 13a, and the inner side wall of the upper case 4 has at a position corresponding to the slot 36 an escape portion 37 for a hub 27 (see Fig. 8). In addition, the inner side wall of the upper case 4 has a side projecting portion 38 on the rear end portion.
As seen from Figs. 1 and Figs. 4 (A) and 4(B), the
lower case 5 is formed into a substantially squared U-shape in cross-section, and a front end portion of the lower case 5 has a fitting stepped portion 40 and a projecting piece 41 at positions corresponding to those of the fitting sttepped portion 30 and the projecting side portion 31, respectively.
The lower case 5 has a through-hole 42 and a forked portion 43 at positions corresponding to those of the through-hole 32 and the forked portion 33 (see Fig. 5).
An outer side wall of the lower case 5 has at a position corresponding to the lower intermediate insertion plate 23 a forked portion 44 which is similar to the forked portion 34 of the upper case 4 and is formed of a rib 44a projecting inward from the outer side wall, and an inner wall of the lower case 5 has an engagement claw 45, which is to be engaged with the engagement hole 35 upon assembly, provided at a position corresponding to that of the engagement hole 35 in such a manner as to project upward from the inner side wall (see Fig. 7).
The outer side wall of the lower case 5 has a slot 46 at a position corresponding to the threaded hole 25, and
the inner side wall of the lower case 5 has an escape portion 47 for the hub 27 (see Fig. 8).
The inner side wall of the lower case 5 has, behind the escape portion 47, a projecting portion 48 around which the side projecting portion 38 is to be fitted upon assembly (see Fig. 9).
The outer side wall of the lower case 5 has at an intermediate position between the through-hole 42 and the forked portion 44 a view window 50 to which a cap 51 is removably fitted (see Fig. 6). The cap 51 may be made from a transparent resin. 43043]
The lower case 5 has at an inner bottom portion 52 near the view window 50 a long reinforcing member 53 which is to forward extend under the lower chain line 12 upon assembly.
The reinforcing member 53 is formed of a metal plate, and has a rear end inserted in a slot 54 and fixed on the bottom portion 52 with a rivet 55.
The reinforcing member 53 has at its front end a
substantially J-shaped bent portion 56 which is inserted in a slit 57 in the rotational direction of the lower chain line 12, that is, from the front side to the rear side in the figure, to be locked therewith, as a result of which the reinforcing member 53 can stably keep the stable mounting state against interference with the lower chain line 12.
As shown in Fig. 9, the solid side projecting portion 48 provided at the rear end portion of the lower case 5 is fitted in the side projecting portion 38 provided at the rear end portion of the upper case 4. At this time, the through-hole 39 formed in a rear end surface of the side projecting portion 38 corresponds to an insert nut 49 buried in the side projecting portion 48.
Next, the mounting of the chain case 3 will be described. As shown in Figs. 1 and 5, with respect to the front end portions of the upper and lower cases 4, 5, the upper and lower insertion plates 20 provided on the cross member 14 of the rear swing arm 2 are inserted into the forked portions 33, 43 respectively, and simultaneously the through-holes 32, 42 formed in the outer side walls are made to correspond to the through-holes 22 formed in the

upper and lower mounting stays 22 and stepped bolts 60 passing through these through-holes are screwed with the weld nuts 22b provided in the mounting stays 22.
As shown in Fig. 7, with respect to the intermediate portions of the upper and lower cases 4, 5, the upper and lower intermediate insertion plates 23 are inserted in the forked portions 34, 44 formed in the outer side walls and the engagement claw 45 on the inner side wall of the lower case 5 is inserted in and engaged with the engagement hole 35 in the inner side wall of the upper wall 4.
As shown in Fig. 8, with respect to the rear end portions of the upper and lower cases 4 and 5, the slots 36, 46 are made to correspond to the threaded holes 25, 26 and stepped bolts 63 passing through the slots 36, 46 via ring rubber members 62 are screwed in the threaded holes 25, 26 respectively. The rear end portions of the upper and lower case 4, 5 are thus floatingly supported. The ring rubber member 62 may be replaced with an elastic resin member .
As shown in Figs. 1 and 9, with respect to the rear
end portions of the upper and lower cases 4 and 5, when the side projecting portion 48 of the lower case 5 is fitted in the side projecting portion of the upper case, the through-hole 39 corresponds to the insert nut 49, and accordingly, the side projecting portions 38, 48 are connected to each other by screwing a bolt 64 passing through the through-hole 39 in the insert nut 49.
In this way, the chain 10 is substantially entirely covered with the chain case 3 excluding the leading end portion to be covered with the sprocket cover 8. In other words, after being covered with the sprocket cover 8, the chain 10 comes to be in a full-cover state, that is, it is not exposed at all. f0052] •
At this time, the upper and lower cases 4, 5 are engaged and connected to each other only by insertion of the front insertion plates 20 and the intermediate insertion plates 23 into the cases 4, 5, vertical engagement of the engagement claw 45 with the engagement hole 35 , and bolt-connection between the fitting portions of the side projecting portions 38, 48 at the rear end portions . Accordingly, if the upper and lower cases 4, 5 are made of a resin which is liable to produce a large molding error and a large difference in thermal expansion therebetween, they can be easily engaged therewith. Also, a thermal deformation of the cases can be prevented by insertion of the front insertion plates and the intermediate insertion plates 23. In particular, a visible deformation of the center portions of the outer side walls of the cases can be prevented by insertion of the intermediate insertion plates 23, so that the appearance of the cases can be kept desirable. [0054-t
Since the rear end portions of the cases 4, 5 is
floatingly supported by fastening the bolts passing through
the slots 36, 46 and the threaded holes 25, 26 via the
rubber mounts 62 and also the slots 36, 46 are longer in
the longitudinal direction of the arm pipe 13a, the
deformation of the cases in the longitudinal direction, if
it is generated by thermal expansion, can be absorbed.
TOOD5]
Accordingly, if there is a difference in thermal expansion caused by the use of different materials for t? rear swing arm 2 and the chain case 3, it can be absoi/ so that it becomes possible to avoid stress concentr
due to the difference in thermal expansion at the stepped bolts 63 of the mounting portions of the cases 4, 5. [0056]
As a result of provision of the reinforcing member 53, if the chain 10 is excessively elongated, the lower chain line 12 first interferes with the reinforcing member 53. The interference between the reinforcing member 53 and the lower chain line 12 causes contact noise, and accordingly, the reinforcing member 53 functions as a sound plate capable of immediately informing the driver of the excessive elongation of the chain 10 by the contact noise.
This makes it possible to adjust the length of the chain 10 before the chain 10 is excessively elongated to the extent that the elongated chain 10 interferes with other portions of the case 3 than the reinforcing member
53.Moreover, since the interference of the chain 10 can be received by the reinforcing member 53, the resin made chain case 3 weak against such interference can be reinforced not to be damaged from the interference with the
chain 10.
Fig. 10 shows a modification of the rubber mount, in which for the lower case 5, a rubber bush 71 is previously fitted in a mounting hole 70 equivalent to the slot 46 and a stepped bolt 63 passing through the rubber bush 71 is screwed in the threaded hole 25.
With this configuration, workability is improved because the rubber bush 71 is not slipped off during assembling operation.
In addition, the rubber mount is sufficient to be performed for at least one portion. However, it may be applied to the front mounting portion using the stepped bolt 60 or to the all mounting portions including the rear end mounting portion using the bolt 64.
Fig. 11 shows a modification of the reinforcing member. In this case, a reinforcing member 75 is made from a suitable elastic material such as rubber or polyurethane foam, and is mounted to an insert nut 77 of the bottom portion 52 by means of the screw
76. With this configuration, the reinforcing member does not function as a sound plate; however, it exhibits a noise suppressing effect because there does not occur contact noise between the reinforcing member and the elongated chain 10.
In this case, since the elongation of the lower chain line 12 can be observed from the view window 50, the excessive elongation of the chain can be prevented by the careful observation, with a result that the provision of the reinforcing member 53 can be also omitted.
The cap 51 is not necessarily provided. For example, part of the lower case 5 may be made transparent to form a view window having an interior observing function similar to that of the window hole.
[Reference Characters]
2: rear swing arm, 3: chain case, 4: upper case, 5: lower case, 13a: pipe arm, 17: end piece, 20: front insertion plate, 23: intermediate insertion plate, 35: engagement hole, 46: slot, 45: engagement projection, 46: slot, 62: ring rubber member, 63: stepped bolt


WE CLAIM;
1. A chain case (3) for a motorcycle, supported by a rear swing arm (2)
swing ably supported by a vehicular body and covering a chain
longitudinally extending over and under said rear swing arm,
characterized in that
said chain case (3) is of a full cover type in which said chain case (3) is divided into an upper case (4) and a lower case (5) and covers the entire chain when said upper (4) and lower (5) cases are mated to each other in the vertical direction;
Each of said upper (4) and lower (5) cases is made from a resin; and
An engagement mechanism for restricting vertical movements of said upper (4) and lower (5) cases is provided at intermediate mating portions of said upper and lower cases.
2. A chain case for a motorcycle as claimed in claim 1, wherein at
least one of mounting portions to said rear swing arm (2) at rear
portions of said upper (4) and lower (5) cases has a floating
structure.
3. A chain case for a motorcycle as claimed in claim 1, wherein each
of said upper (4) and lower (5) cases has an intermediate outer side
wall which is fixed by insertion to an upward or downward
projecting member provided on said rear swing arm (2).
4. A chain case for a motorcycle as claimed in claim 1, wherein said lower case (5) has on an inner surface thereof a reinforcing member provided under a chain line.
5. A chain case for a motorcycle as claimed in claim 4, wherein said reinforcing member is made from a metal.

6. A chain case for a motorcycle according to claim 4, wherein said reinforcing member is made from an elastic material.

7. A chain case for a motorcycle according to claim 1, wherein said $). chain case is provided with on a side surface thereof, a view window for checking elongation of said chain.

8. A chain case for a motorcycle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.


Documents:

455-del-1997-abstract.pdf

455-del-1997-claims.pdf

455-del-1997-correspondence-others.pdf

455-del-1997-correspondence-po.pdf

455-del-1997-description (complete).pdf

455-del-1997-drawings.pdf

455-del-1997-form-1.pdf

455-del-1997-form-13.pdf

455-del-1997-form-19.pdf

455-del-1997-form-2.pdf

455-del-1997-form-3.pdf

455-del-1997-form-4.pdf

455-del-1997-form-6.pdf

455-del-1997-gpa.pdf

455-del-1997-petition-137.pdf

455-del-1997-petition-138.pdf

anstract.jpg


Patent Number 214900
Indian Patent Application Number 455/DEL/1997
PG Journal Number 10/2008
Publication Date 07-Mar-2008
Grant Date 18-Feb-2008
Date of Filing 24-Feb-1997
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 HITOSHI SUZUKI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
2 YASUHIRO HIGASHI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
3 AKIHITO KOBAYASHI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
4 YUJI TSUJIMOTO C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
5 MASAKI FUJIWARA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
PCT International Classification Number F16H 7/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI-8-076030 1996-03-29 Japan