Title of Invention

VALVE DEVICE

Abstract The present invention relates to a valve device having a body and first and second covers all of which is made of a synthetic resin. In welding them together by ultrasonic wave, it is avoided that substantially L-shaped connecting pipe portions integrally provided on the covers obstruct the welding, and a sufficient connection margin is ensured. The first connecting pipe portion 30 a having a tip end positioned at a location inwards from a weld zone 51 between the body 29 and the first cover 30 is integrally connected at its base end to the first cover 30 in such a manner that the base end is offset from a central portion of the first cover 30, and the second connecting pipe portion 42 a having a tip end positioned at a location inwards from a weld zone 52 between the body 29 and the second cover 42 is integrally connected at its base end to the second cover 42 in such a manner that the base end is offset from a central portion of the second cover 42.
Full Text The present invention relates to a valve device suitably-used for a secondary air control valve or the like in an engine, more particularly to a valve device comprising a first cover which has a substantially L-shaped first connecting pipe portion integrally provided thereon and which is coupled to a body having a valve seat to define a valve chamber facing the valve seat between the first cover and the body, a second cover which has a substantially L-shaped second connecting pipe portion integrally provided thereon and which is coupled to the body, a diaphragm having a peripheral edge clamped between the second cover and the body, a rod connected to a central portion of the diaphragm and protruding into the valve chamber and a valve member which is mounted on the rod and capable of being seated on the valve seat, the rod being urged by a spring in a direction to move the valve member away from the valve seat. DESCRIPTION OF THE RELATED ART
There is a valve device conventionally known, for example, from Japanese Utility Model Publication No.61-4009 which includes a first cover coupled to a body to define a valve chamber between the first cover and the body, and a second cover also coupled to the body and clamping a peripheral edge of a diaphragm between the second cover and the body.

To provide an improvement in vibration-proof property by a reduction in weight of such a valve device mounted on a vehicle and an improvement in corrosion resistance, it is considered that the first and second covers are formed of a synthetic resin. In this case, when the first and second covers are welded to the body by ultrasonic wave, reductions in numbers of parts and assembling steps can be advantageously provided without loosening of the parts, as compared with a structure in which first and second covers are fastened to the body by screw members.
In some cases, substantially L-shaped connecting pipe portions are integrally provided on the first and second covers. In this case, if a margin of connection is set at a substantially large value in each of the connecting pipe portions, there is a possibility that when the first and second covers are welded to the body by ultrasonic wave, tip ends of the connecting pipe portions may obstruct the welding, resulting in an insufficient weld strength of the first and second covers welded to the body at portions corresponding to the tip ends of the connecting pipe portions. If the connecting pipe portions are shortened to ensure that the tip ends of the connecting pipe portions do not obstruct the welding, a connection margin for connecting a hose or the like is insufficient, and for this reason, there is also a possibility that the hose may be detached.

SUMMARY OF THE INVENTION Accordingly, It is an object of the present Invention to provide a valve device In which each of the body and the first and second covers are formed of a synthetic resin and welded together by ultrasonic wave so that It Is possible to avoid that the substantially L-shaped connecting pipe portions Integrally provided on the first and second covers do not obstruct the welding, and a sufficient margin of connection can be ensured In the connecting pipe portions.
To achieve the above object, according to a first aspect and feature of the present Invention, there Is provided a valve device, comprising a body having a valve seat In a central portion of which a fluid passage and a valve bore leading to the fluid passage are opened, a first cover integrally provided with a substantially L-shaped first connecting pipe portion and coupled to the body, a diaphragm having a peripheral edge clamped between the body and the first cover, the diaphragm defining a first pressure chamber leading to the first connecting pipe portion between the diaphragm and the first cover and a second pressure chamber between the diaphragm and the body, a second cover Integrally provided with a substantially L-shaped second pipe portion and coupled to the body to define, between the second cover and the body, a valve chamber to which the second connecting pipe portion leads and which faces the valve seat, a rod which is connected at its one end to a central portion of the diaphragm and axlally movably

carried in the body and which is passed coaxially through the valve bore to protrude into the valve chamber, and a valve member mounted to the rod and capable of being seated on the valve seat, the rod being urged by a spring in a direction to move the valve member away from the valve seat, wherein the first and second covers each formed of a synthetic resin are welded to the body made of a synthetic resin by ultrasonic wave; the first connecting pipe portion having a tip end positioned at a location inwards from a weld zone between the body and the first cover is integrally connected at its base end to the first cover in such a manner that the base end is offset from a central portion of the first cover; and the second connecting pipe portion having a tip end positioned at a location inwards from a weld zone between the body and the second cover is integrally connected at its base end to the second cover in such a manner that the base end is offset from a central portion of the second cover.
With this arrangement of the first feature, each of the body and the first and second covers is formed of the synthetic resin, and the first and second covers are welded to the body by ultrasonic wave. Therefore, it is possible to provide an improvement in vibration-proof property by a reduction in the weight of the valve device mounted on a vehicle and an improvement in corrosion resistance. Moreover, it is possible to provide a reduction in parts and a reduction in assembling steps, and to prevent the occurrence of a loosening, as compared

with a structure in which first and second covers are fastened to the body by screw members. In addition, the tip ends of the substantially L-shaped first and second connecting pipe portions are positioned at the locations respectively inwards from the weld zone between the body and the first cover and the weld zone between the body and the second cover. Therefore, when the first and second connecting pipe portions are welded to the body by ultrasonic wave, the tip ends of the first and second connecting pipe portions cannot obstruct the welding, and it is possible to sufficiently increase the weld strength of the first and second connecting pipe portions welded to the body at portions corresponding to the tip ends of the first and second connecting pipe portions. Moreover, the base ends of the-first and second connecting pipe portions are integrally connected to the first and second covers at the locations offset from the central portions of the first and second covers. Therefore, the tip ends of the connecting pipe portions can be positioned at the locations where they do not obstruct the ultrasonic wave welding, and a margin of connection for the connecting pipe portions can be set at a sufficiently large value.
According to a second aspect and feature of the present invention, in addition to the first feature, the valve device further includes a return spring of a coiled type mounted with its one end abutting against the body and exerting a spring force for urging the valve member oscillatably mounted to the rod in

a direction away from the valve seat, and a spring-receiving member which includes a ring plate portion surrounding the rod, and a plurality of engage claws integrally provided on an inner periphery of the ring plate portion in such a manner that the engage claws bite into an outer periphery of the rod at a plurality of points in a circumferential direction of the rod, the spring-receiving member being fixed to the rod in such a manner that the other end of the return spring abuts against the ring plate portion.
With such arrangement of the second feature, the valve member is oscillatably mounted to the rod and hence, even if an axis of the rod is inclined to some extent with respect to an axis of the valve bore, the valve member can be reliably seated on the entire periphery of the valve seat and thus, the amount of fluid flowing can be controlled at an increased accuracy. Moreover, the spring-receiving member for preventing the spring force of the return spring from reaching the valve member to ensure the free oscillating movement of the valve member is mounted directly to the rod. Therefore, it is possible to minimize the increase in weight due to the mounting of the spring-receiving member to the rod, to thereby contribute to an improvement in vibration-proof property of the valve device by a reduction in weight.
According to a third aspect and feature of the present invention, in addition to the first or second feature, the valve member is formed of a hard rubber. With such arrangement, it

is possible to suppress the striking sound generated upon the seating of the valve member on the valve seat, while providing a reduction in manufacture cost of the valve member. Moreover, the weight of the valve member can be reduced, to thereby further contribute to an improvement in vibration-proof property of the valve device by a reduction in weight.
According to a fourth aspect and feature of the present invention, in addition to the first feature, the valve member has a through-bore provided in its central portion in such a manner that the rod is passed loosely through the through-bore to enable the oscillation of the valve member relative to the rod, and an annular seal member is disposed, to surround the rod between the valve member and a seal-receiving member fixed to the other end of the rod to be able to receive the seal member so that the seal member can be resiliently brought into contact with the valve member at an open end edge of the through-bore on the side opposite from the valve seat.
With such arrangement of the fourth feature, the valve member is capable of being oscillated relative to the rod and hence, even if an axis of the rod is inclined to some extent with respect to an axis of the valve bore, the valve member can be reliably seated on the entire periphery of the valve seat. Moreover, the annular seal member is pushed toward the valve member by the seal-receiving member and resiliently brought into contact with the valve member at the open end edge of the through-bore on the side opposite from the valve seat, thereby

inhibiting the flowing of the fluid between an inner surface of the through-bore and an outer surface of the rod. Therefore, the valve bore can be reliably closed to control the amount of flowing of the fluid at an increased accuracy.
According to a fifth aspect and feature of the present invention, in addition to the fourth feature, a spring-receiving member is fixed to the rod on the side of the valve member opposite from the seal member, and a return spring is mounted between the spring-receiving member and the body for urging the rod in a direction to move the valve member away from the valve seat. With such arrangement, it is possible to inhibit the movement of the valve member toward the diaphragm by the spring-receiving member, while permitting the free oscillation of the valve member relative to the rod.
According to a sixth aspect and feature of the present invention, in addition to the fifth feature, the spring-receiving member includes a ring plate portion which receives one end of the return spring of a coiled type whose other end abuts against the body in such a manner that the ring plate portion surrounds the rod, and a plurality of engage claws integrally provided on an inner periphery of the ring plate portion to bite into the outer periphery of the rod at a plurality of points in a circumferential direction of the rod. With such arrangement, the spring-receiving member receiving the other end of the return spring is mounted directly to the rod and hence, the return spring can be received on the rod, and it is possible

to reduce the number of parts and the number of assembling steps.
According to a seventh aspect and feature, in addition to the sixth feature, each of the engage claws is formed inclined in such a manner that it is getting away from the return spring in a radially inner direction of the rod in order to apply the spring load of the return spring in a direction to force the engage claws to bite into the rod. With such arrangement, when the rod is inserted through the spring-receiving member from the side of the other end, the engage claws can be prevented from being brought into engagement with the rod, thereby facilitating the assembling of the spring-receiving member to the rod. Thus, the spring-receiving member can be reliably fixed to the rod in such a manner that the engage claws are allowed to bite into the rod under the action of the spring force of the return spring. In addition, it is possible to minimize the movement of the valve member toward the diaphragm by inhibiting the movement of the valve member toward the diaphragm by the tip ends of the engage claws, while permitting the free oscillating movement of the valve member relative to the rod.
According to an eighth aspect and feature of the present invention, in addition to any of the fifth to seventh features, the spring-receiving member is formed of a stainless steel. With such arrangement, it is possible to improve the corrosion resistance of the spring-receiving member to the fluid flowing between the valve chamber and the fluid passage, to thereby improve its durability.

According to a ninth aspect and feature of the present invention, in addition to the first feature, the body is provided with a substantially C-shaped support plate portion; an elastic member is mounted on the support plate portion and formed into a rectangular tubular shape, and has an engage groove for engagement of the support plate portion in its outer periphery and a rectangular fitting bore in its central portion; and a portion of a fixed support member is fitted in the fitting bore of the elastic member.
With such arrangement of the ninth feature, the elastic member may have a volume enough to be mounted to the support plate portion provided on the body and hence, it is possible to reduce the amount of a material for forming the elastic member, to thereby provide a reduction in cost. Moreover, it is possible to suppress the vibration amplitude of the body to a low level by suppressing the vibration amplitude of the entire elastic member to a relatively low level. Further, the support plate portion is of the substantially C-shape, and the elastic member is formed into the rectangular tubular shape and has the engage groove for engagement of the support plate portion in its outer periphery and the rectangular fitting bore at its central portion. Therefore, it is possible to easily mount the elastic material to the support plate portion by pushing the elastic member to the support plate portion.
According to a tenth aspect and feature of the present invention, in addition to the ninth feature, the support plate

portions are provided at least at two points on the body; the elastic members are mounted to the support plate portions, respectively; and portions of the support members corresponding to the elastic members are fitted into the fitting bores of the elastic members, respectively. With such arrangement, the body can be supported stably and resiliently.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs.l to 11 show an embodiment of the present invention, wherein
Fig. 1 is a diagram showing an engine and a secondary air control device in a connected relation;
Fig. 2 is. a side view of the secondary air control device;
Fig.3 is a plan view taken in the direction of an arrow 3 in Fig.2;
Fig.4 is a sectional view taken along a line 4-4 in Fig.3;
Fig.5 is a perspective view of a rod;
Fig.6 is an enlarged vertical sectional view of a seal-receiving member, taken along a line 6-6 in Fig.7;
Fig. 7 is a bottom view taken in the direction of an arow 7 in Fig.6;
Fig.8 is an enlarged vertical sectional view of a

spring-receiving member, taken along a line 8-8 in Fig.9;
Fig.9 is a bottom view taken in a direction of an arrow 9 in Fig.8;
Fig.10 is a sectional view taken along a line 10-10 in Fig.2; and
Fig.11 is a sectional view taken along a line 11-11 in Fig.10.
DESCRIPTION OF THE PREFERRED EMBQDTMF.NT The present invention will now be described by way of an embodiment with reference to Figs.l to 11. Referring first to Fig.l, a an intake pipe 17 is connected to an intake port 15 in an engine mounted on a vehicle, and constitutes an intake passage 16 together with the intake port 15. A fuel injection valve 18 is mounted to the engine E for injecting fuel into the intake port 15, and a throttle valve 19 is provided in the intake pipe 17 for controlling the amount of air drawn into the intake passage 16. An exhaust pipe 22 having a catalytic converter (not shown) incorporated therein is connected to an exhaust port 20 in the engine E, and constitutes an exhaust passage 21 together with the exhaust port 20.
To supply the outside air purified in an air cleaner 23 as a secondary air to the exhaust passage 21 in response to the pulsation of an exhaust gas in the exhaust passage 21, the air cleaner 23 and the exhaust port 20 in the exhaust passage 21 are connected to each other through a secondary air supply

passage 24. Thus, during usual operation of the engine E, the oxidization of unburned components in the exhaust gas is promoted by the secondary air. Therefore, when the negative pressure in the intake passage 16 is increased steeply due to the rapid closing of the throttle valve 19, there is a possibility that the concentration of the fuel in a fuel-air mixture supplied to the engine E is increased, whereby the amount of the unburned components discharged into the exhaust passage 21 is increased abnormally and hence, the unburned components are burned explosively by the secondary air supplied from the second air supply passage 24, which may lead to produce a so-called after-burn phenomenon. For this reason, when the negative pressure in the intake passage 16 is increased steeply, it is necessary to stop the supplying of the second air from the secondary air supply passage 24. Therefore, a secondary air control device 25 is incorporated in the secondary air supply passage 24 for permitting the supply of the secondary air by the pulsation of the exhaust gas and for stopping the supply of the second air when the negative pressure in the intake passage 16 is increased steeply.
The secondary air control device 25 is comprised of a diaphragm actuator 26, a secondary air control valve 27 driven to be closed by the diaphragm actuator 26, and a reed valve 28 interposed between the secondary air control valve 27 and the exhaust passage 21 to permit only the flow of air toward the exhaust passage 21.

Referring also Figs.2 to 4, the diaphragm actuator 26 comprises a body 29 made of a synthetic resin, a first cover 30 made of a synthetic resin and coupled to the body 29, and a diaphragm 31 with its peripheral edge clamped between the body
29 and the first cover 30 . The diaphragm 31 is formed by molding from a synthetic rubber, a natural rubber or an elastomer. A first pressure chamber 32 is defined between the first cover
30 and the diaphragm 31, and a second pressure chamber 33 is defined between the diaphragm 31 and the body 29.
A first connecting pipe portion 30a bent into a substantially L-shape is integrally connected at its base end to the first cover 30, and a negative pressure-introducing hose 34 is connected at one end thereof to a tip end of the first connecting pipe portion 30a so as to lead to the inside of the first pressure chamber 32, and at the other end thereof to the intake pipe 17 at a location downstream from the throttle valve 19, as shown in Fig.l. Thus, a negative pressure in the intake passage 16 acts on the first pressure chamber 32.
A rod 35 made of a metal and coaxial with the diaphragm
31 is axially movably carried in the body 29 and connected at
one end thereof directly to a central portion of the diaphragm
31 on the side of the second pressure chamber 33.
Referring to Fig, 5, the rod 35 is integrally provided at one end with a disk portion 35a which is coupled by molding to a central portion of the diaphragm 31, whereby the rod 35 is connected at one end directly to the central portion of the

diaphragm 31. Moreover, a plurality of through-bores 36 are provided in the disk portion 35a, so that the synthetic resin, the natural rubber or the elastomer flows into the through-bores 36 during formation of the diaphragm 31 by molding, whereby the one end of the rod 35 is coupled by molding with an increased strength to the diaphragm 31.
A buffer portion 37 is formed into a circular shape integrally with the diaphragm 31 at the central portion of the diaphragm 31 on the side of the second pressure chamber 33 to surround the rod 35 coaxially. The buffer portion 37 protrudes toward the body 29 in such a manner that it is brought into contact with the body 29 upon the flexing of the diaphragm 31 toward the body 29 in response to a difference between the pressures in the first and second pressure chambers 32 and 33.
In the diaphragm actuator 26, when the negative pressure in the intake passage 16 is increased steeply, the diaphragm 31 is flexed in a direction to decrease the volume of the first pressure chamber 32, whereby rod 35 is operated upwards as viewed in Fig.4.
The secondary air control valve 27 includes a valve housing 39, the rod 35 connected at its one end to the diaphragm 31 of the diaphragm actuator 26, a valve member 40 oscillatably mounted to the rod 35, and a return spring 41 mounted between the valve housing 39 and the rod 35.
The valve housing 39 is comprised of the body 29 constituting a portion of the diaphragm actuator 26, and a

second cover 42 made of a synthetic resin and coupled to the body 29.
The body 29 includes an air passage 43, a communication bore 44 providing communication between the air passage 43 and the second pressure chamber 33 in the diaphragm actuator 26, a valve bore 45 disposed coaxially with the rod 35 so as to lead to an upstream end of the air passage 43, a valve seat 46 in a central portion of which the valve bore 45 opens on the side opposite from the air passage 43, and a tubular support portion 47 inserted partially and coaxially into the valve bore 45. The rod 35 passed coaxially through the valve bore 45 is axially slidably fitted into the tubular support portion 47. A valve chamber 48 is defined between the body 29 and the second cover 42, and the valve seat 46 is formed into an annular shape on the body 29 to face the valve chamber 48.
A second connecting pipe portion 42a bent into a substantially L-shape is integrally connected at its base end to the second cover 42, and a hose 49 constituting an upstream portion of the secondary air supply passage 24 leading to the air cleaner 23 is connected to a tip end of the second connecting pipe portion 42a. A hose 50 constituting a downstream portion of the secondary air supply passage 24 on the side of the exhaust passage 21 is connected to the body 29 so as to lead to a downstream end of the air passage 43.
The body 29 and the first cover 30 each made of a synthetic resin are welded to each other at an annular weld zone 51 by

ultrasonic wave, and the first connecting pipe portion 30a integrally provided on the first cover 30 is integrally formed on the first cover 30 in such a manner that its tip end is positioned at a location inwards with a distance 61 from the weld zone 51 and its base end is positioned at a location offset from the center CI of the first cover 30 with an offset amount of 62.
The body 29 and the second cover 42 formed of a synthetic resin are welded to each other at an annular weld zone 52 by ultrasonic wave, and the second connecting pipe portion 42a integrally provided on the second cover 42 is integrally formed on the second cover 42 in such a manner that its tip end is positioned at a location inwards with a distance 63 from the weld zone 52 and its base end is positioned at a location offset from the center C2 of the first cover 42 with an offset amount of 84.
The valve member 40 is formed into a disk shape from a hard rubber having a hardness Hs of, for example, 70 or more, and is accommodated in the valve chamber 48 and integrally provided with an annular seat portion 40a capable of being seated on the valve seat 46. On the other hand, the rod 35 connected at one end to the diaphragm 31 and passed coaxially through the valve bore 45 protrudes at the other end thereof into the valve chamber 48, and is passed loosely through a through-bore 53 provided in the central portion of the valve

member 40.
A seal-receiving member 54 is fixed at the other end of the rod 35, and an annular seal member 55 such as an 0-ring is disposed between the seal-receiving member 54 and the valve member 40 to surround the rod 35, while the seal member can be resiliently brought into contact with the valve member 40 at an open end edge of the through-bore 53 on the side opposite from the valve seat 46.
Referring to Figs.6 and 7, the seal-receiving member 54 is formed of, for example, a stainless steel to have an improved corrosion resistance to moisture contained in the air flowing between the valve chamber 48 and the air passage 43 to thereby improve durability, and includes a ring plate portion 54a surrounding the rod 35, and a plurality of, e.g., six engage claws 54b integrally provided around an inner periphery of the ring plate portion 54a.
Each of the engage claws 54b is formed inclined in such a manner that it is getting away from the valve member 40 in a radially inner direction of the rod 35. Moreover, the rod 35 is provided with a shallow V-groove 56 (see Fig. 5) into which the tip ends of the engage claws 54b are engaged so as to bite into the rid 35. Thus, the seal-receiving member 54 is fixed to the rod 35 by inserting the rod 35 into the seal-receiving member 54 from the other end side so as to bring the tip ends of the engage claws 54b into engagement in the V-groove 56.
A spring-receiving member 57 is fixed to the rod 35 on

the side opposite from the seal member 55 with the valve member 40 therebetween, and a coiled-type return spring 41 urging the rod 35 away from the valve seat 46 is mounted between the spring-receiving member 57 and the body 29, to surround the tubular support portion 47 and the rod 35.
Referring to Figs.8 and 9, the spring-receiving member 57 is formed of, for example, a stainless steel to have an improved corrosion resistance to moisture contained in the air flowing between the valve chamber 48 and the air passage 43 to thereby improve durability, and includes a ring plate portion 57a positioned at a location spaced apart from the valve member 40 to surround the rod 35, and a plurality of, e.g. , six engage claws 57b integrally provided around an inner periphery of the ring plate portion 57a, and a cylindrical portion 57c integrally connected to an outer periphery of the ring plate portion 57. The return spring 41 having one end abutting against the body 29 is received at the other end thereof by the ring plate portion 57a in such a manner that its position in a radial direction of the rod 35 is limited by the cylindrical portion 57c. Each of the engage claws 57b is formed inclined in such a manner that it is getting away from the return spring 41 in a radially inner direction of the rod 35 in order to apply the spring load of the return spring 41 in a direction to force the engage claws 57b to bite into the rod 35. The rod 35 is provided with a shallow V-groove 58 (see Fig.5) into which tip ends of the engage claws 57b are engaged to bite into the rod 35.

In this manner, the valve member 40 is mounted to the rod 35 between the seal member 55 received by the seal-receiving member 54 and the spring-receiving member 57, and there is a clearance between an inner surface of the through-bore 53 provided in the central portion of the valve member 40 and an outer surface of the rod 35 passed loosely through the through-bore 53. Therefore, the valve member 40 is oscillatably mounted to the rod 35.
Referring also to Figs.10 and 11, the body 29 which is a portion of the valve housing 39 in the secondary air control valve 27, has support plate portions 59, 59 integrally provided thereon at least at two points (two points in the present embodiment) circumferentially spaced apart from each other to protrude outwards. The support plate portions 59 are formed into a substantially C-shape.
The support plate portions 59, 59 are supported on support members 60, 60 fixed to a vehicle body frame (not shown) with elastic members 61, 61 interposed therebetween.
The elastic member 61 is formed into a rectangular tubular shape and has an engage groove 61a for engagement of the support plate portion 59 in its outer periphery and a rectangular fitting bore 62 in its central portion. The elastic member 61 is mounted to the support plate portion 59 in such a manner that the support plate portion 59 is engaged into the engage groove 61a. A fitting plate portion 60a is provided at a tip end of the support member 60 and fitted into the fitting bore 62.

Moreover, a tip end of the fitting plate portion 60a is formed into a substantially T-shape so that it can protrude out of the fitting bore 62 to engage the elastic member 61, and opposite sides 63, 63 of the tip end of the fitting plate portion 60a are formed as slants which are closer to each other towards the tip end in order to facilitate the fitting of the fitting plate portion 60a into the fitting bore 62.
The operation of this embodiment will be described below. In the diaphragm actuator 26, the disk portion 35a at one end of the rod 35 is connected directly to the diaphragm 31. Therefore, any part other than the rod 35 and the diaphragm 31 is not required for connecting the rod 35 and the diaphragm 31 to each other, leading to a reduced number of parts for the diaphragm actuator 26.
The rod 35 made of the metal is connected at one end by molding to the central portion of the diaphragm 31 formed by molding from synthetic resin, natural rubber or elastomer, and hence, the rod 35 is connected to the diaphragm 31 simultaneously with the forming of the diaphragm 31. Therefore, it is possible to reduce the number of steps of assembling the diaphragm actuator 26 and to prevent the air leakage between the first and second pressure chambers 32 and 33 at a connection between the rod 35 and the diaphragm 31, thereby eliminating one of causes of the air leakage.
The central portion of the valve member 40 of the secondary air control valve 27 is provided with the through-bore 53

through which the rod 35 is passed loosely to enable the oscillation of the valve member 40 relative to the rod 35. The annular seam member 55 is disposed between the seal-receiving member 54 fixed to the rod 35 for receiving the seal member 55 and the valve member 40, and surrounds the rod 35 so that it can be resiliently brought into contact with the valve member 40 at the open end edge of the through-bore 53 on the side opposite from the valve seat 46 provided on the body 29.
Therefore, the valve member 40 can be oscillated relative to the rod 35, and thus, even if an axis of the rod 35 is inclined to some extent with respect to the an axis of the valve bore 45, the valve member 40 can be reliably seated on the entire periphery of the valve seat 46. Moreover, the annular seal member 55 is pushed toward the valve member 40 by the seal-receiving member 54, whereby it is resiliently brought into contact with the valve member 40 at the open end edge of the through-bore 53 on the side opposite from the valve seat 46. Therefore, the flowing of the air between the inner surface of the through-bore 53 and the outer surface of the rod 35 is inhibited and hence, the valve bore 45 can be reliably closed, thereby controlling the amount of flow of the secondary air at an enhanced accuracy.
The spring-receiving member 57 having the ring plate portion 57a positioned at the location apart from the valve member 40 is fixed to the rod 35 on the side of the valve member 40 opposite from the seal member 55, and the return spring 41

for urging the rod 35 away from the valve seat 46 is mounted between the ring plate portion 57a of the spring-receiving member 57 and the body 29 . Therefore, the movement of the valve member 40 toward the diaphragm 31 can be inhibited by the spring-receiving member 57, while permitting the free oscillation of the valve member 40 relative to the rod 35.
Moreover, the spring-receiving member 57 includes the ring plate portion 57a receiving the return spring 41 and surrounding the rod 35, and the plurality of engage claws 57b integrally provided around the inner periphery of the ring plate portion 57a to bite into the outer periphery of the rod 35 at the plurality of circumferential points on the rod 35. Each of the engage claws 57b is formed inclined in such a manner that it is getting away from the return spring 41 in a radially inner direction of the rod 35 in order to apply the spring load of the return spring 41 in the direction to force the engage claws 57b to bite into the rod 35.
Therefore, the spring-receiving member 57 receiving the return spring 41 can be mounted directly to the rod 35, and hence, the return spring 41 can be received on the side of the rod 35 to reduce the number of parts and the number of assembling steps, as compared with a valve device in which a spring-receiving member is fixed to a rod by a clip and thus, two parts are required.
Moreover, it is possible to facilitate the assembling of the spring-receiving member 57 to the rod 35 in such a manner

the engage claws 57b are not brought into engagement with the rod 35, when the rod 35 is inserted through the spring-receiving member 57 from the side of the other end, and to reliably fix the spring-receiving member 57 to the rod 35 in such a manner that the engage claws 57b are forced to bite into the rod 35 by the spring force of the return spring 41. In addition, it is possible to minimize the movement of the valve member 40 toward the diaphragm 31 by inhibiting the movement of the valve member 40 toward the diaphragm 31 by the tip ends of the engage claws 57b, while permitting the free oscillation of the valve member 40 relative to the rod 35.
The valve member 40 is formed of the hard rubber having a hardness Hs of, for example, 70 or more and hence, it is possible to suppress the striking sound made in the seating of the valve member 40 on the valve seat 46, while providing a reduction in manufacture cost of the valve member 40, and to minimize the rubbing sound produced between the rod 35 and the valve member 40. Further, it is possible to suppress the wear between the rod 35 and the valve member 40, to supress an increase in the amount of air leakage.
In the valve device comprising the diaphragm actuator 26 and the secondary air control valve 27, the first and second covers 30 and 42 are coupled to the body 29. More specifically, the first and second covers 30 and 42 both formed of a synthetic resin are welded by ultrasonic wave to the body 29 made of a synthetic resin. Therefore, it is possible to improve

vibration-proof property of the valve device by a reduction in weight of the valve device mounted on the vehicle, and to improve corrosion resistance. Moreover, it is possible to reduce the number of parts and the number of assembling steps and to prevent the occurrence of the loosening, as compared with a valve device in which first and second covers 30 and 42 are coupled to a body 29 by screw members.
Furthermore, the first and second connecting pipe portions 30a and 42a of the substantially L-shape are integrally provided on the first and second covers 30 and 42. The first connecting pipe portion 30a having the tip end positioned at a location inwards from the weld zone 51 between the body 29 and the first cover 30 is integrally connected at its base end to the first cover 30 in such a manner that the base end is offset from the central portion of the first cover 30, and the second connecting pipe portion 42a having the tip end positioned at a location inwards from the weld zone 52 between the body 29 and the second cover 42 is integrally connected to the second cover 42 in such a manner that the base end is offset from the central portion of the second cover 42.
Therefore, when the first and second covers 30 and 42 are welded to the body 29 by ultrasonic wave, the tip ends of the connecting pipe portions 30a and 42a do not obstruct the welding, and the weld strength of the first and second covers 30 and 42 welded to the body 29 can be sufficiently increased at portions corresponding to the tip ends of the connecting pipe portions

30a and 42a. Moreover, since the first and second connecting portions 30a and 42a are integrally connected at their base ends to the covers 30 and 42 with their base ends offset from the central portions of the first and second covers 30 and 42, the tip ends of the connecting pipe portions 30a and 42a can be positioned at locations where they do not obstruct the ultrasonic wave welding, and a margin of connection of the hoses 34 and 49 to the connecting pipe portions 30a and 42a can be set at a sufficiently large value.
Moreover, the spring-receiving member 57 for preventing the spring force of the return spring 41 from reaching the valve member 40 to ensure the free oscillating movement of the valve member 40 is mounted directly to the rod 35, as described above. Therefore, it is possible to minimize the increase in weight due to the mounting of the spring-receiving member 57 to the rod 35, to contribute to an improvement in vibration-proof property of the valve device attributable to the reduction in weight, and the reduction in weight of the valve device 40 by forming the valve member 40 from a hard rubber can also contribute to the improvement in vibration-proof property of the valve device.
To support the valve housing 39 of the secondary air control valve 27 on the vehicle body frame, the substantially C-shaped support plate portions 59, 59 are provided at two points on the body 29 of the valve housing 39, and the elastic members 61, 61 are mounted on the support plate portions 59,

59. Also, portions of the support members 60, 60 are fitted in the fitting bores 62, 62 in the elastic members 61, 61.
In this structure to support the valve housing 39, the elastic member 61 may have a volume enough to be mounted on the support plate portion 59 provided on the valve housing 39. Therefore, as compared with a structure in which an elastic member 61 is mounted to surround the entire valve housing 39, the amount of a material for forming the elastic member 61 can be reduced to provide a reduction in cost and moreover, and the vibration amplitude of the secondary air control valve 27 can be suppressed to a low level by suppressing the vibration amplitude of the entire elastic member 61 to a relatively low level.
Further, the support plate portion 59 is of the substantially C-shape, and the elastic member 61 is formed into the rectangular tubular shape and has, in its outer periphery, the engage groove 61a into which the support plate portion 59 is fitted, and the fitting groove 62 provided in its central portion. Therefore, the elastic member 61 can be easily mounted to the support plate portion 59 by pushing the elastic member 61 into the support plate portion 59, leading to an improved assemblability of the elastic member 61.
In addition, the support plate portions 59, 59 are provided at least at two points on the valve housing 39, and the elastic members 61, 61 are mounted on the support plate portions 59, 59, respectively. Portions of the support members

60, 60 are fitted in the fitting bores 62, 62 in the elastic members 61, 61, respectively. Therefore, the secondary air control valve 27 can be supported stably and resiliently.
Further, the diaphragm actuator 26 for opening and closing the secondary air control valve 27 is constituted of the valve housing 39 made of a synthetic resin, the first cover 30 made of a synthetic resin and coupled to the valve housing 39, and the diaphragm 31 having the peripheral edge clamped between the valve housing 39 and the first cover 30. Therefore, the weights of the secondary air control valve 27 and the diaphragm actuator 26 can be minimized, thereby providing a more excellent vibration-proof property.
Although the embodiment of the present invention has been described in detail, it will be understood that the present invention is not limited to the above-described embodiments, and various modifications in design may be made without departing from the spirit and scope of the invention defined in claims.
For example, in the above-described embodiment, one end of the rod 35 is connected directly to the diaphragm 31 of the diaphragm actuator 26 by coupling under molding, but the present invention is applicable to a valve device in which one end of a rod 35 is connected to one of a pair of retainers which clamp a central portion of a diaphragm 31.


WE CLAIM: 1. A valve device, comprising a body (29) having a valve seat (46) in a central portion of which a fluid passage (43) and a valve bore (45) leading to said fluid passage (43) are opened, a first cover (30) integrally provided with a substantially L-shaped first connecting pipe portion (30a) and coupled to said body (29), a diaphragm (31) having a peripheral edge clamped between said body (29) and said first cover (30), the diaphragm (31) defining a first pressure chamber (32) leading to said first connecting pipe portion (30a) between said diaphragm (31) and said first cover (30) and a second pressure chamber (33) between said diaphragm (31) and said body (29), a second cover (42) integrally provided with a substantially L-shaped second pipe portion (42a) and coupled to said body (29) to define, between said second cover (42) and said body (29), a valve chamber (48) to which said second connecting pipe portion (42a) leads and which faces said valve seat (46), a rod (35) which is connected at its one end to a central portion of said diaphragm (31) and axially movably carried in said body (29) and which is passed coaxially through said valve bore (45) to protrude into said valve chamber (48), and a valve member (40) mounted to said rod (35) and capable of being seated on said valve seat (46), said rod (35) being urged by a spring in a direction to move said valve member (40) away from said valve seat (46), wherein said first and second covers (30 and 42) each formed of a synthetic resin are welded to said body (29) made of a

synthetic resin by ultrasonic wave; said first connecting pipe portion (30a) having a tip end positioned at a location inwards from a weld zone (51) between said body (29) and said first cover (35) is integrally connected at its base end to said first cover (30) in such a manner that the base end is offset from a central portion of said first cover (30); and said second connecting pipe portion (42a) having a tip end positioned at a location inwards from a weld zone (52) between said body (29) and said second cover (42) is integrally connected at its base end to said second cover (42) in such a manner that the base end is offset from a central portion of said second cover (42).
2. A valve device according to claim 1, comprising a return spring (41) of a coiled type mounted with its one end abutting against said body (29) and exerting a spring force for urging said valve member (40) oscillatably mounted to said rod (35) in a direction away from said valve seat (46), and a spring-receiving member (57) which includes a ring plate portion (57a) surrounding said rod (35) and a plurality of engage claws (57b) integrally provided on an inner periphery of said ring plate portion (57a) in such a manner that the engage claws bite into an outer periphery of said rod (35) at a plurality of points in a circumferential direction of said rod (35) , said spring-receiving member (57) being fixed to said rod (35) in such a manner that the other end of said return spring ( 41) abuts against said ring plate portion (57a).

3. A valve device according to claim 1 or 2, wherein said valve member (40) is formed of a hard rubber.
4. A valve device according to claim 1, wherein said valve member (40) has a through-bore (53) provided in its central portion in such a manner that said rod (35) is passed loosely through said through-bore (53) to enable the oscillation of said valve member (40) relative to said rod (35), and an annular seal member (55) is disposed to surround said rod (35) between said valve member (40) and a seal-receiving member (54) fixed to the other end of said rod (35) to be able to receive said seal member (55) so that said seal member (55) can be resiliently brought into contact with said valve member (40) at an open end edge of said through-bore (53) on the side opposite from said valve seat (46).
5. A valve device according to claim 1, --^"comprising
a spring-receiving member (57) fixed to said rod (35) on the side of said valve member (40) opposite from said seal member (55), and a return spring (41) mounted between said spring-receiving member (57) and said body (29) for urging said rod (35) in a direction to move said valve member (40) away from said valve seat (46).
6. A valve device according to claim 5, wherein said

spring-receiving member (47) includes a ring plate portion (57a) which receives one end of said return spring (41) of a coiled type whose other end abuts against said body (29) in such a manner that the ring plate portion (57a) surrounds said rod (35), and a plurality of engage claws (57b) integrally provided on an inner periphery of said ring plate portion (57a) to bite into the outer periphery of said rod (35) at a plurality of points in a circumferential direction of said rod (35).
7. A valve device according to claim 6, wherein each of said engage claws (57b) is formed inclined in such a manner that it is getting away from said return spring (41) in a radially inner direction of said rod (35) in order to apply the spring load of said return spring (41) in a direction to force said engage claws (57b) to bite into said rod (35).
8. A valve device according to any of claims 5 to 7, wherein said spring-receiving member (57) is formed of a stainless steel.
9. A valve device according to claim 1, wherein the body (29) is provided with a substantially C-shaped support plate portion (59), and an elastic member (61) is mounted on the support plate portion (59) and formed into a rectangular tubular shape, said elastic member (61) having an engage groove (61a) for engagement of said support plate portion (59) in its outer periphery and

a rectangular fitting bore (62) in its central portion, and a fixed support member (60) a portion of which is fitted in said fitting bore (62) of said elastic member (61).
10. A valve device according to claim 9, wherein said support plate portions (29) are provided at least at two points on said body (35); said elastic members (61) are mounted to said support plate portions (59), respectively; and portions of said support members (60) corresponding to said elastic members (61) are fitted into said fitting bores (62) of said elastic members (61), respectively.

Documents:

618-mas-2001 abstract duplicate.pdf

618-mas-2001 abstract.pdf

618-mas-2001 claims duplicate.pdf

618-mas-2001 claims.pdf

618-mas-2001 correspondence others.pdf

618-mas-2001 correspondence po.pdf

618-mas-2001 description (complete) duplicate.pdf

618-mas-2001 description (complete).pdf

618-mas-2001 drawings duplicate.pdf

618-mas-2001 drawings.pdf

618-mas-2001 form-1.pdf

618-mas-2001 form-19.pdf

618-mas-2001 form-26.pdf

618-mas-2001 form-3.pdf

618-mas-2001 form-5.pdf

618-mas-2001 others-1.pdf

618-mas-2001 others-2.pdf

618-mas-2001 others.pdf

618-mas-2001 petition.pdf


Patent Number 211915
Indian Patent Application Number 618/MAS/2001
PG Journal Number 02/2008
Publication Date 11-Jan-2008
Grant Date 13-Nov-2007
Date of Filing 27-Jul-2001
Name of Patentee M/S. KEIHIN CORPORATION
Applicant Address 3-17 SHINJUKU 4-CHOME, SHINJUKU-KU, TOKYO,
Inventors:
# Inventor's Name Inventor's Address
1 YOSHIO SAITO C/O KAKUDA DEVELOPMENT CENTER OF KEIHIN CORPORATION, 197-1, KAKUDA AZA NAGARE, KAKUDA-SHI, MIYAGI,
2 SETSUO OOTSUKI C/O KAKUDA DEVELOPMENT CENTER OF KEIHIN CORPORATION, 197-1, KAKUDA AZA NAGARE, KAKUDA-SHI, MIYAGI,
3 TOSHIYUKI SUGIMOTO C/O KAKUDA DEVELOPMENT CENTER OF KEIHIN CORPORATION, 197-1, KAKUDA AZA NAGARE, KAKUDA-SHI, MIYAGI,
4 TADAP ,UKAI C/O KAKUDA THIRD OFFICE OF KEIHIN CORPORATION, 4-3 SAKURA AZA MIYAYACHI, KAKUDA-SHI, MIYAGI,
PCT International Classification Number F 16 K 31/126
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2000-231426 2000-07-27 Japan
2 2000-231428 2000-07-27 Japan
3 2000-231425 2000-07-27 Japan