JP2013096305A - Exhaust gas control valve and method of installing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the improper operation of a shaft 4 and a valve lock due to the entry of foreign matter from the flow passage hole side to the bearing device side of a valve body 1.SOLUTION: A bearing device for rotatably supporting a shaft valve (the shaft 4 formed integrally with a valve 5) in the storage hole 21 of the valve body 1 and the bearing hole 24 of a bearing holder 10 includes twin ball bearings 11, 12 continuously disposed in the direction of the rotating axis of the shaft 4, and an oil seal 13 disposed further on the flow passage hole side than the twin ball bearings 11, 12. The entry of foreign matter such as the particulate matter and welding spatters contained in the EGR gas from the flow passage hole side to the bearing device side (twin ball bearing side) of the valve body 1 through an insertion hole 26 can be prevented by the gasket function of the oil seal 13. Consequently, the improper operation and valve locking of the shaft valve can be prevented from occurring.

Description

  The present invention relates to an exhaust gas control valve that controls exhaust gas flowing through a flow path hole formed in a housing, and an assembling method thereof.

[Conventional technology]
Conventionally, a part of the exhaust gas is used for the purpose of reducing harmful substances (for example, nitrogen oxides: NOx) contained in the exhaust gas discharged from the combustion chamber of an internal combustion engine (engine) such as a diesel engine. An exhaust gas circulation device (EGR system) having an EGR gas pipe for recirculating (recirculating) certain EGR gas from an exhaust passage to an intake passage is known.
This EGR system incorporates an EGR gas flow rate control valve (EGRV) that controls the flow rate of the EGR gas flowing inside the EGR gas pipe.

  As shown in FIG. 8, the EGRV is formed in a housing 101 coupled in the middle of the EGR gas pipe, a cylindrical nozzle 103 press-fitted into a press-fitting hole 102 formed in the housing 101, and the nozzle 103. A valve 105 rotatably accommodated in the flow passage hole 104, a shaft 107 fixed to a fitting hole 106 formed in the valve 105, and the valve 105 is opened and closed through the shaft 107. An actuator and a return spring 108 that urges the valve 105 in the valve closing operation direction are provided (see, for example, Patent Documents 1 to 5).

In the EGRV, an annular seal ring groove is formed in the entire outer periphery of the valve 105, and a C-shaped seal ring 109 is attached to the seal ring groove.
The EGRV includes a support mechanism (bearing mechanism for the shaft 107) that rotatably supports the shaft 107 with respect to the housing 101. This bearing mechanism includes a bearing sleeve 111, a metal bearing 112, an oil seal 113, and a ball bearing 114 that are integrally formed with the housing 101.
The bearing sleeve 111 of the housing 101 includes a bearing hole 115 that extends straight in the direction of the rotation axis of the shaft 107.
An opening 121 is formed on one end side of the bearing hole 115 in the axial direction. The opening 121 opens at the hole wall surface of the flow path hole 104.
An opening 122 is formed on the other end side in the axial direction of the bearing hole 115. The opening 122 opens at the hole wall surface of the gear storage chamber 124 that stores the gear reduction mechanism including the valve gear 123.

Here, the EGRV press-fits and fixes the ball bearing 114 to the outer periphery of the shaft 107 after press-fitting and fixing the bearing sleeve 111 and the metal bearing 112 to the bearing sleeve 111 of the housing 101. The shaft 107 integrated with the ball bearing 114 is inserted into the bearing hole 115 through the opening 122 on the gear housing chamber side, and penetrates the oil seal 113, the metal bearing 112, and the opening 121 on the flow path hole side. To do.
One end portion of the shaft 107 passing through the opening 121 in the rotation axis direction protrudes into the flow path hole 104. Then, after one end portion of the shaft 107 in the rotation axis direction is press-fitted into the fitting hole 106 formed in the valve 105, the valve 105 and the shaft 107 are fixed by welding.

The metal bearing 112 is press-fitted and fixed in a press-fitting hole formed in the bearing sleeve 111. Inside the metal bearing 112, there is formed a sliding hole for supporting the sliding portion of the shaft 107 so as to be slidable in the rotational direction. A sliding clearance for smoothly rotating the shaft 107 inside the metal bearing 112 is formed between the sliding portion of the shaft 107 and the hole wall surface of the sliding hole of the metal bearing 112.
In the metal bearing 112 and the ball bearing 114, the metal bearing 112 has a larger radial clearance with respect to the shaft 107. Therefore, in the conventional design, the metal bearing 112 is arranged at a predetermined distance in the rotation axis direction from the ball bearing 114. The shaft runout of the shaft 107 was suppressed.

[Conventional technical problems]
However, in the conventional EGRV, in the bearing hole 115, the metal bearing 112 is disposed on the channel hole side of the oil seal 113, and the bearing hole 115 communicates with the channel hole 104 via the opening 121. Therefore, foreign matter contained in the EGR gas flowing through the flow path hole 104 enters the sliding clearance between the shaft 107 and the metal bearing 112, and the hole wall surface of the sliding portion of the shaft 107 and the sliding hole of the metal bearing 112 And the sliding resistance of the shaft 107 with respect to the metal bearing 112 increases. As a result, the rotational movement of the shaft 107 is hindered, and the valve block and the shaft 107 may malfunction.
In addition, foreign substances that enter the sliding clearance include particulate matter such as combustion residue and carbon contained in EGR gas (hydrocarbons adhering to soot and soot, black smoke, incomplete combustion products, etc.) There is a deposit of fixed fine particles (particulates).
Further, the foreign matter that enters the sliding clearance includes welding spatter that is generated when the valve 105 and the shaft 107 are welded because the valve 105 and the shaft 107 are welded and fixed in the flow path hole 104 of the housing 101. .

By the way, when the nozzle 103 is press-fitted and fixed to the press-fitting hole 102 formed in the housing 101 before the welding operation of the valve 105 and the shaft 107, that is, when the nozzle 103 is pre-fitted to the press-fitting hole 102 of the housing 101. There is a possibility that welding spatter adheres to the inner peripheral surface (sliding surface) of the nozzle 103, and in this case, a sliding failure between the nozzle 103 and the seal ring 109 may occur.
In addition, when the nozzle 103 is press-fitted and fixed to the press-fitting hole 102 formed in the housing 101 later than the welding operation of the valve 105 and the shaft 107, that is, when the nozzle 103 is retrofitted to the press-fitting hole 102 of the housing 101, There is a possibility that welding spatter adheres to the hole wall surface of the press-fitting hole 102 of the housing 101. In this case, the nozzle 103 may not be press-fitted and fixed to the press-fitting hole 102 of the housing 101.

JP 2005-233303 A JP 2007-285111 A JP 2008-196437 A JP 2009-002325 A Japanese Patent No. 4285267 Japanese Patent No. 4600319

An object of the present invention is to provide an exhaust gas control valve capable of preventing malfunction and locking of a shaft due to entry of foreign matter from a flow path side of a housing to a bearing device side, and an assembling method thereof.
It is another object of the present invention to provide an exhaust gas control valve capable of preventing a sliding failure between a nozzle and a seal ring, and an assembling method thereof.
Another object of the present invention is to provide an exhaust gas control valve capable of easily assembling a nozzle into a press-fitting hole of a housing (valve body), and an assembling method thereof.

The invention (exhaust gas control valve) according to claim 1 includes a housing having a flow path through which exhaust gas (for example, an internal combustion engine) passes, a housing hole opened in a wall surface of the flow path, and a flow path of the housing. A valve that opens and closes the flow path, a shaft that is housed in the housing hole of the housing and provided with the valve, and a bearing device that is housed in the housing hole of the housing and rotatably supports the shaft. It has.
The bearing device includes a plurality of rolling bearings that are continuously arranged in the rotation axis direction of the shaft, and a gasket that is arranged on the flow path side of these rolling bearings.
The plurality of rolling bearings rotatably support a shaft provided with a valve with respect to the housing hole (bearing hole) of the housing.
Further, the gasket seals an annular gap formed between the hole wall surface of the housing accommodation hole (bearing hole) and the outer peripheral surface (sliding portion) of the shaft.

According to the first aspect of the present invention, as a bearing device that rotatably supports a shaft provided with a valve in a housing hole (bearing hole) of a housing, a plurality of shafts continuously arranged in the direction of the rotation axis of the shaft are provided. By providing the rolling bearings and the gaskets disposed closer to the flow path than these rolling bearings, it is possible to prevent foreign substances from entering from the flow path side of the housing to the bearing device side (a plurality of rolling bearing sides) by the gasket. it can.
As a result, it is possible to prevent malfunction or locking of the shaft provided with the valve accompanying entry of foreign matter from the flow path side of the housing to the bearing device side.
In addition, since a plurality of rolling bearings are used without using a metal bearing as a bearing device, even if a foreign object enters the bearing device side from the flow path side of the housing, the shaft provided with a valve may malfunction. Locking can be prevented.
In addition, since a plurality of rolling bearings are continuously arranged in the rotation axis direction of the shaft, the shaft runout of the shaft is equivalent to the conventional design. In addition, the shaft runout of the shaft of the exhaust gas control valve is the same as that of the conventional design, even if a plurality of rolling bearings are not spaced apart by a predetermined axial distance. )it can. Thereby, it becomes possible to arrange | position a gasket to the flow path side rather than a some rolling bearing.

According to the second aspect of the present invention, the accommodation hole (housing or bearing hole) includes two first and second press-fitting holes formed on the same axis as the accommodation hole. These first and second press-fitting holes are arranged at a predetermined distance in the direction of the rotation axis of the shaft.
According to the third aspect of the present invention, the plurality of rolling bearings includes a first outer ring portion (for example, a press-fit fixing portion with respect to the housing or the holder) that is press-fitted and fixed to the first press-fit hole of the housing (or the holder). Yes. Further, the gasket includes a second outer ring portion (for example, a press-fit fixing portion for the housing or the holder) that is press-fitted and fixed to the second press-fit hole of the housing (or the holder).
The first press-fitting hole has a larger inner diameter than the second press-fitting hole. In addition, the second press-fitting hole is disposed closer to the flow path of the housing than the first press-fitting hole.

According to the fourth aspect of the invention, the shaft is installed (arranged) so as to penetrate the housing hole (or the bearing hole or insertion hole of the holder) in the center line direction.
According to the fifth aspect of the present invention, the projecting portion that projects into the flow path of the housing is provided on one end side in the rotation axis direction of the shaft. That is, a part of the shaft (projection) protrudes from the housing hole side of the housing to the flow path side.
According to the sixth aspect of the present invention, the valve accommodated in the flow path of the housing so as to be rotatable (openable and closable) is constituted by a shaft and an integral part. Further, a valve is integrally formed on the protruding portion of the shaft. Thereby, the shaft and the valve are integrally formed, that is, a shaft valve subassembly is formed.
Thereby, the formation position and formation angle of the valve with respect to the shaft can be assembled with high accuracy. Further, since welding spatter does not remain in the housing, it is possible to prevent malfunction and locking of the shaft provided with a valve accompanying the entry of foreign matter such as welding spatter from the flow path side of the housing to the bearing device side.

According to the seventh aspect of the present invention, the valve accommodated in the flow path of the housing so as to be freely rotatable (openable and closable) is configured as a separate part with respect to the shaft. Moreover, the valve is assembled | attached to the protrusion part of the shaft. For example, before assembling the shaft into the housing hole of the housing, the shaft and the valve are assembled by welding or fastening. That is, the shaft and the valve are integrated by post-assembly (shaft valve subassembly).
Thereby, the formation position and formation angle of the valve with respect to the shaft can be assembled with high accuracy. Further, for example, since welding spatter does not remain in the housing when the shaft and the valve are welded and fixed, operation failure of the shaft provided with the valve due to intrusion of foreign matters such as welding spatter from the flow path side of the housing to the bearing device side, Locking can be prevented.

According to the invention described in claim 8, the bearing device includes a plurality of rolling bearings and a cylindrical holder for holding the gasket. This holder is configured as a separate part with respect to the housing.
Before assembling the valve and the shaft into the housing hole and flow path of the housing, the valve, the shaft and the bearing device are integrated (shaft valve subassembly) by assembling the valve and the shaft to the holder of the bearing device. be able to.

According to the ninth aspect of the present invention, the holder (or the bearing device) includes the bearing hole extending in the direction of the rotation axis of the shaft. In addition, the housing includes an insertion hole through which a bearing hole of the holder (or bearing device) and the flow path of the housing communicate and a shaft provided with a valve can be inserted.
The insertion hole is an elliptical hole or a circular hole having a diameter larger than the outer diameter of the valve and smaller than the outer diameter of the holder (or bearing device) (for example, the outer diameter of the holder (or bearing device)> the insertion hole. Hole diameter> valve outer diameter).
In addition, when the outer diameter of the valve is larger than the outer diameter of the holder (or bearing device), the housing hole (two first and second press-fitting holes) is scraped off at the outer peripheral portion of the valve. A gap is formed between the housing hole and the outer surface of the holder (or bearing device). Thereby, the problem that the exhaust gas flowing through the flow path of the housing leaks out of the housing through the gap can be solved.

The invention according to claim 10 (exhaust gas control valve) includes a housing, a valve, a shaft, a bearing device (a plurality of rolling bearings, gaskets, holders, etc.) and a valve in a valve closing operation direction or with respect to the shaft. A spring for applying a load (spring load, spring load) in the valve opening operation direction is provided.
The spring is a return spring (or an opener spring or an overturn spring) that urges a valve accommodated in the flow path of the housing in the valve closing operation direction (or valve opening operation direction).

According to the eleventh aspect of the present invention, the bearing device (or holder) includes the cylindrical bearing sleeve disposed so as to surround the shaft in the circumferential direction.
The spring includes a coil that spirally surrounds the bearing sleeve of the bearing device (or holder).
The bearing sleeve of the bearing device (or holder) includes a press-fit portion (press-fit fixing portion) that is press-fitted and fixed in the housing hole of the housing, and a spring guide that holds the inner diameter surface of the coil of the spring.
When a spring inner diameter holding portion is provided on the side of a cylindrical boss formed integrally with the housing as in a conventional EGR gas flow control valve (EGRV), the bearing sleeve is press-fitted and fixed in the housing hole. If configured in this manner, the physique of the housing, particularly the physique in the radial direction perpendicular to the rotational axis direction of the shaft, becomes large. As in the invention according to claim 11, the bearing sleeve is press-fitted and fixed in the housing hole. If a spring guide is provided on the side and the inner diameter surface of the spring is held by the bearing sleeve of the bearing device (or holder), it is integrally formed in the housing like a conventional EGR gas flow control valve (EGRV) The outer diameter of the spring is equivalent to the case where the spring inner diameter holding portion is provided on the cylindrical boss portion side. Therefore, the size of the exhaust gas control valve can be reduced, and the mountability of the exhaust gas control valve can be improved.

According to the twelfth aspect of the present invention, as the plurality of rolling bearings, a plurality of ball bearings that rotatably support the shaft with respect to the housing (or the holder) in the housing receiving hole may be adopted. . A roller bearing may be used instead of the ball bearing.
According to the invention described in claim 13, the gasket is an oil seal that seals an annular gap formed on the outer peripheral side of the shaft (and between the housing hole wall surface of the housing or the bearing hole wall surface of the holder). . This oil seal can pivotally support the shaft so as to be rotatable (slidable in the rotational direction) with respect to the housing (or holder) within the housing hole of the housing. A packing that hermetically seals the annular gap may be used instead of the oil seal.

According to the invention described in claim 14, the housing includes a valve body having a press-fit hole formed on the same axis as the flow path, and a cylindrical nozzle having a flow path formed therein. .
The nozzle is configured as a separate part with respect to the valve body.
The nozzle includes a press-fit fixing portion that is press-fitted and fixed in the press-fitting hole of the valve body.
According to the fifteenth aspect of the present invention, the seal ring is provided that seals an annular gap formed between the circumferential wall surface of the nozzle and the circumferential end surface of the valve when the valve is fully closed.
The exhaust gas control valve is provided with an annular groove in which a seal ring is mounted on the entire circumferential end surface of the valve.
The seal ring is fitted in the annular groove of the valve so as to be rotatable integrally with the valve and the shaft.

According to a sixteenth aspect of the present invention (an exhaust gas control valve assembling method), a shaft valve subassembly is formed by assembling a bearing device to a shaft valve in which the valve is integrally formed with the shaft, and then the housing. The process of assembling the shaft valve subassembly in the (or valve body) receiving hole, and then press-fitting and fixing the nozzle (press-fit fixing portion) into the press-fitting hole of the housing (or valve body) to form the housing sub-assembly. Process.
The invention according to claim 17 (method for assembling an exhaust gas control valve) includes the step of assembling a bearing device to a shaft to form a shaft subassembly, and then assembling the valve to the shaft subassembly. A step of forming an assembly, a step of assembling a shaft valve subassembly in a housing hole of the housing (or valve body), and a nozzle (a press-fitting fixing portion) of the nozzle in the press-fitting hole of the housing (or valve body). And press-fitting and forming a housing subassembly.

According to the sixteenth and seventeenth aspects of the present invention, when the nozzle is first press-fitted and fixed to the press-fitting hole formed in the housing (or valve body) rather than the assembly work of the valve and the shaft, that is, the housing Even when the nozzle is attached to the press-fitting hole of the (or valve body), weld spatter does not remain in the housing (or valve body).
Therefore, foreign matter such as welding spatter can be prevented from biting between the nozzle and the seal ring, so that sliding failure between the nozzle and the seal ring can be prevented.
Also, when assembling the nozzle into the press-fitting hole formed in the housing (or valve body) later than when assembling the valve and shaft, that is, when attaching the nozzle to the press-fitting hole in the housing (or valve body) Even so, it is possible to prevent foreign matter such as welding spatter from adhering to the wall surface of the press-fitting hole of the housing (or valve body), so that the nozzle cannot be press-fitted and fixed to the press-fitting hole of the housing (or valve body). Can be resolved.
Therefore, since the nozzle can be easily assembled in the press-fitting hole of the housing (valve body), the productivity of the exhaust gas control valve can be improved.

It is the front view which showed the EGR gas flow control valve (EGRV) (Example 1). (Example 1) which is AA sectional drawing of FIG. (A) is the top view which showed the housing (valve body) which press-fits a shaft subassembly, (b) is BB sectional drawing of (a) (Example 1). (A)-(d) is process drawing (sectional drawing) which showed the assembly | attachment order of EGRV (Example 1). (E)-(g) is process drawing (sectional drawing) which showed the assembly | attachment order of EGRV (Example 1). (A)-(f) is process drawing (sectional drawing) which showed the assembly | attachment order of EGRV (Example 2). (G)-(k) is process drawing (sectional drawing) which showed the assembly | attachment order of EGRV (Example 2). It is sectional drawing which showed the EGR gas flow control valve (EGRV) (conventional technique).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention provides a shaft provided with a valve in a housing hole (bearing hole) in the housing hole (bearing hole) for the purpose of preventing malfunction and locking of the shaft due to entry of foreign matter from the flow path hole side of the housing to the bearing device side. By providing a plurality of rolling bearings continuously arranged in the rotation axis direction of the shaft as a bearing device to be rotatably supported, and a gasket arranged on the flow path hole side from these rolling bearings, This was achieved by preventing the entry of foreign matter from the flow path hole side to the bearing device side (multiple rolling bearing side) with a gasket.
The purpose of the present invention is to prevent a sliding failure between the nozzle and the seal ring and to easily assemble the nozzle into the press-fitting hole of the housing (valve body). This was realized by integrating the valve and the shaft before press-fitting (the press-fitting fixing part).

[Configuration of Example 1]
FIGS. 1 to 5 show a first embodiment of the present invention. FIGS. 1 and 2 show an EGR gas flow rate control valve (EGRV). FIG. 3 shows a housing for press-fitting and fixing a shaft subassembly. It is the figure which showed the valve body.

The exhaust system for an internal combustion engine of this embodiment recycles EGR gas, which is part of exhaust gas discharged from the combustion chamber of each cylinder of an internal combustion engine (engine) having a plurality of cylinders, from the exhaust pipe to the intake pipe. An exhaust gas circulation device (EGR system) for circulation (recirculation) is provided.
Here, a direct injection diesel engine in which fuel is directly injected into the combustion chamber is employed as the engine.
An intake port and an exhaust port communicate with the combustion chamber for each cylinder of the engine. An intake manifold and an exhaust manifold are connected to each cylinder of the engine. Each cylinder of the engine is equipped with an injector that injects and supplies fuel into the combustion chamber.

The intake pipe connected to the intake manifold is provided with an air cleaner, a turbocharger compressor, an intercooler, and a throttle valve. An intake passage that communicates with a combustion chamber and an intake port for each cylinder of the engine is formed inside the intake manifold and the intake pipe. The intake manifold and the intake pipe are provided with an EGR gas merging portion (merging portion) for merging EGR gas introduced from the EGR system with clean outside air (fresh air) filtered by an air cleaner.
In the exhaust pipe connected to the exhaust manifold, a turbocharger turbine, an exhaust purification device (catalyst or diesel particulate filter: DPF), and a muffler are installed. An exhaust passage communicating with the combustion chamber and the exhaust port for each cylinder of the engine is formed inside the exhaust manifold and the exhaust pipe. The exhaust manifold and the exhaust pipe are provided with an EGR gas branch (branch) that branches EGR gas, which is part of engine exhaust gas, to the EGR system.

The EGR system includes an EGR gas pipe that recirculates (refluxs) a part of exhaust gas into the intake passage of the engine as EGR gas, and an EGR gas flow rate control valve (EGR control) that controls the flow rate of the EGR gas that flows inside the EGR gas pipe. And an exhaust gas control valve (hereinafter referred to as EGRV) and an engine control unit (electronic control device, EGR valve control device: hereinafter referred to as ECU) that variably controls the opening degree of the EGRV based on the operating state of the engine. ing.
One end of the EGR gas pipe is connected to the EGR gas branching section, and the other end of the EGR gas pipe is connected to the EGR gas merging section.
The EGRV includes a housing (valve body 1, nozzle 2, nozzle holder 3) coupled in the middle of the EGR gas pipe, and a heat-resistant metal shaft valve (shaft 4, valve 5, A seal ring 6), a motor that generates power (torque) for driving the shaft valve, a speed reduction mechanism having an output gear (valve gear) 7 that rotates in response to the torque of the motor, a valve body 1 and a valve gear 7; A return spring 8, a sensor cover 9 that holds an EGR opening sensor, and a bearing device that rotatably supports the shaft 4 of the shaft valve (bearing holder 10, double ball bearings 11, 12, oil) And a seal 13).
The shaft 4 constitutes an EGRV shaft valve by integrating the valve 5 and the seal ring 6. The motor constitutes an EGRV actuator with a speed reduction mechanism.

The EGRV housing includes a heat-resistant metal valve body 1 that houses a shaft valve, a return spring 8 and a bearing device therein, and a heat-resistant metal nozzle (sleeve shape) for protecting the valve body 1 from the heat of EGR gas. Liner) 2 and a nozzle holder 3 for holding the nozzle 2.
The valve body 1 is formed with passage holes 14 to 18 through which EGR gas introduced from the exhaust pipe of the engine passes. The valve body 1 is integrally formed with a cylindrical nozzle holder that surrounds the periphery of the nozzle 2 and the nozzle holder 3 in the circumferential direction. A press-fitting hole 19 formed on the same axis as the axis of the flow path holes 14 to 17 is formed on the inner periphery of the nozzle holder.

The valve body 1 is formed with a housing chamber 20 for housing the speed reduction mechanism between the sensor cover 9 and a housing hole 21 for housing the return spring 8 and the bearing device.
The valve body 1 is integrally formed with a cylindrical bearing sleeve 22 disposed so as to surround the periphery of the bearing device in the circumferential direction. On the inner peripheral surface of the bearing sleeve 22, a press-fit hole 23 formed on the same axis as the axis of the accommodation hole 21 is formed.
Further, the valve body 1 has a housing hole 21, a bearing hole 24, and flow passage holes 16 to 18, and a partition that functions as a bearing restricting portion that restricts the press-fitting and fixing position of the bearing holder 10 of the bearing device. 25 is integrally formed. The partition wall 25 is formed with an insertion hole 26 that allows the accommodation hole 21 and the bearing hole 24 to communicate with the flow path holes 16 to 18.

In the nozzle 2, a communication path (flow path hole) 16 that connects the flow path holes 14 and 15 and the flow path holes 17 and 18 is formed.
In the nozzle holder 3, a communication path (flow path hole) 15 that connects the flow path hole 14 and the flow path holes 16 to 18 is formed. A press-fit hole 27 formed on the same axis as the axis of the flow path hole 15 is formed on the inner periphery of the nozzle holder 3.
The details of the housing, particularly the valve body 1, the nozzle 2 and the nozzle holder 3 will be described later.

The shaft valve includes a shaft 4 that is rotatably accommodated in the accommodation hole 21 of the valve body 1 and a bearing hole 24 of the bearing device, a valve 5 that opens and closes flow path holes 14 to 18 formed in the housing, A seal ring 6 attached to the outer periphery of the valve 5 is provided. The shaft valve is an integral part in which the valve 5 and the shaft 4 are integrally molded.
The shaft 4 is installed so as to penetrate the housing hole 21 of the valve body 1 and the bearing hole 24 of the bearing device in the direction of the center line thereof. One end of the shaft 4 in the direction of the rotation axis protrudes from the flow path wall surface of the partition wall 25 of the valve body 1 into the flow path holes 14 to 17 of the housing. Further, the other end side of the shaft 4 in the rotation axis direction protrudes from the wall surface of the bearing device into the accommodating chamber 20 of the valve body 1.
The valve 5 is integrally formed on one end side of the shaft 4 in the rotation axis direction. Further, a seal ring 6 that can be brought into close contact with a valve seat surface 29 that is an inner peripheral surface of the nozzle 2 is fitted into a circumferential groove (annular concave groove: hereinafter referred to as a seal ring groove) 28 on the outer periphery of the valve 5. It is. The details of the shaft valve, particularly the shaft 4, the valve 5 and the seal ring 6, will be described later.

The bearing device is a shaft valve support device that rotatably supports a shaft valve, and includes a cylindrical bearing holder 10 and a double ball bearing (rolling) continuously arranged in the direction of the rotation axis of the shaft 4 of the shaft valve. Ball bearings) 11 and 12 and oil seals (gaskets) 13 disposed on the flow path hole side with respect to the double ball bearings 11 and 12.
The bearing holder 10 is configured as a separate part with respect to the housing (the valve body 1, the nozzle 2, and the nozzle holder 3). The bearing holder 10 is formed with a bearing hole 24 extending in the rotation axis direction of the shaft 4. The bearing holder 10 includes two first and second bearing sleeves (cylindrical outer ring portions) 31 and 32 and double ball bearings arranged so as to surround the shaft 4 of the shaft valve in the circumferential direction. The first annular wall 33 having a function as a first restricting portion for restricting the press-fitting and fixing positions 11 and 12 and the second annular wall 34 having a function as a second restricting portion for restricting the press-fit and fixing position of the oil seal 13. Are integrally formed.

A first press-fit hole 35 formed on the same axis as the axis of the bearing hole 24 is formed on the inner periphery of the first bearing sleeve 31 of the bearing holder 10. Further, a second press-fit hole 36 formed on the same axis as that of the bearing hole 24 and the first press-fit hole 35 is formed on the inner periphery of the second bearing sleeve 32. That is, two first and second press-fit holes 35 and 36 are formed on the inner periphery of the bearing holder 10. The first and second press-fitting holes 35 and 36 are arranged at a predetermined distance in the rotation axis direction of the shaft 4.
The double ball bearings 11 and 12 are an inner ring 41 that is press-fitted and fixed to the outer periphery of the axial direction portion (sliding portion) of the shaft 4, and a first outer ring that is press-fitted and fixed to the first press-fitting hole 35 of the first bearing sleeve 31. An outer ring 42 having a function as a portion, and a plurality of steel balls 43 slidably accommodated between two race rings of the inner ring 41 and the outer ring 42 are provided.
The oil seal 13 has a function as a seal lip 44 that is in sliding contact with the sliding surface of the shaft 4 of the shaft valve and a second outer ring portion that is press-fitted into the second press-fit hole 36 of the second bearing sleeve 32. A cylindrical portion 45 is provided.
The details of the bearing device, particularly the bearing holder 10, the double ball bearings 11 and 12, and the oil seal 13 will be described later.

The EGR system includes an EGR gas pipe, EGRV. In the EGR system, when the EGRV is opened, a part of the exhaust gas discharged from the engine is returned to the intake passage as EGR gas via the EGR gas pipe.
The EGR system includes an ECU that controls energization of a motor that is a power source of the actuator.
The EGR gas pipe is an exhaust gas recirculation pipe (EGR pipe) that connects an exhaust passage upstream of the turbine and an intake passage downstream of the intercooler or throttle valve. Alternatively, it is an exhaust gas recirculation pipe (EGR pipe) that connects an exhaust passage downstream of the turbine or the exhaust purification device and an intake passage upstream of the compressor. An exhaust gas passage (EGR gas passage) for recirculating (refluxing) the EGR gas from the exhaust passage to the intake passage is formed inside the EGR gas pipe.

The EGRV recirculates (refluxs) from the exhaust passage to the intake passage via the EGR gas passage by changing the opening area of the EGR gas passage (flow passage holes 14 to 18) continuously or stepwise. It is an exhaust gas flow rate control valve that variably controls the flow rate of EGR gas (EGR gas amount). As a result, the EGR rate, which is the ratio of the EGR gas amount to the total flow rate of the intake air supplied to the combustion chamber for each cylinder of the engine, is controlled.
The valve body 1 is formed in a predetermined shape by, for example, a die-casting of a heat-resistant aluminum alloy or an aluminum alloy-based casting, or a heat-resistant material having excellent heat resistance (for example, an iron-based casting or cast iron).
The valve body 1 is fastened and fixed to the EGR gas pipes (or the EGR gas branching portion of the exhaust pipe or the EGR gas merging portion of the intake pipe) arranged before and after (upstream and downstream) using fastening bolts. The valve body 1 is a housing that holds the valve 5 and the shaft 4 of the shaft valve so as to be openable and closable (rotatable) in the rotation direction from the fully closed position to the fully open position.

Next, details of the housing of the present embodiment will be briefly described with reference to FIGS.
The valve body 1 is formed in a predetermined shape from a heat-resistant metal. Inside the valve body 1, a nozzle 2, a nozzle holder 3, a shaft valve, a return spring 8, and a bearing device are disposed.
Inside the valve body 1 and the nozzle 2, passage holes 14 to 18 having a circular cross section through which the EGR gas passes are formed. The flow path holes 14 to 18 are exhaust gas flow paths (fluid flow paths, internal flow paths of the valve body 1) that recirculate EGR gas from the EGR gas branching portion of the exhaust pipe to the EGR gas merging portion of the intake pipe.
The channel hole 14 is formed on the upstream side (or downstream side) of the EGR gas flow direction with respect to the channel holes 15 and 16. Further, the flow path hole 15 is formed inside the nozzle holder 3. Further, the flow path hole 16 is formed inside the nozzle 2.

The valve body 1 is integrally formed with a cylindrical nozzle holder (nozzle fitting portion) so as to surround the periphery of the nozzle 2 in the circumferential direction. A press-fitting hole 19 having a circular cross-section into which the nozzle 2 is press-fitted is formed on the inner peripheral surface of the nozzle holder. Note that the inner diameter of the press-fitting hole 19 is smaller than the outer diameter of the nozzle holder 3.
The nozzle holder of the valve body 1 is integrally formed with an annular wall (step) 46 that functions as a restricting portion that restricts the press-fitting and fixing position of the nozzle holder 3 that is formed separately.
The valve body 1 includes a cylindrical bearing sleeve 22 arranged to surround the bearing device in the circumferential direction, and a cylindrical spring holder arranged to surround the return spring 8 in the circumferential direction. 47 is integrally formed. A cylindrical housing recess for housing the return spring 8 is formed between the outer periphery of the first bearing sleeve 31 of the bearing holder 10 and the inner periphery of the spring holder 47. The bottom surface of the housing recess is a spring seat 48 that engages one end of the return spring 8 in the axial direction.

A housing hole 21 for housing the return spring 8 and the bearing device is formed inside the spring holder 47.
On the inner peripheral surface of the bearing sleeve 22, a press-fitting hole 23 having a circular section in which the bearing holder 10 is press-fitted is formed. The inner diameter of the press-fit hole 23 is smaller than the outer diameter of the bearing holder 10.
On the flow path side of the bearing sleeve 22, a partition wall (partition wall) 25 that divides the internal space of the valve body 1 into flow path holes 16 to 18, accommodation holes 21, and bearing holes 24 is provided.
The partition wall 25 is formed with an insertion hole 26 that allows the housing hole 21 and the bearing hole 24 to communicate with the flow path holes 16 to 18 and allows the shaft 4 of the shaft valve to be inserted therethrough. The insertion hole 26 opens at the wall surface of the flow path holes 16 to 18. The insertion hole 26 is an elliptical hole having a diameter larger than the outer diameter of the valve 5 of the shaft valve and smaller than the outer diameter of the bearing holder 10.
That is, the outer diameter of the bearing holder 10> the hole diameter of the insertion hole 26> the outer diameter of the valve 5 of the shaft valve.

The nozzle 2 is formed in a cylindrical shape from a heat-resistant metal. The outer diameter of the nozzle 2 is smaller than the hole diameters of the flow path holes 14 and 15 and larger than the inner diameter of the press-fitting hole 19. Further, the nozzle 2 has a sliding surface (valve seat surface) 29 on a portion (inner peripheral surface) slidably contacting the outer peripheral surface (sliding portion) of the seal ring 6 fitted in the seal ring groove 28 of the valve 5. ing. The valve seat surface 29 is constituted by a part of a spherical surface (concave surface) having a radius of curvature centered on a central point formed on the rotation axis of the valve 5.
The nozzle 2 has a press-fit fixing portion that is press-fitted into the inner peripheral surface of the nozzle holder 3 (the hole wall surface of the press-fit hole 27). The corner (edge) of the press-fit fixing portion is tapered chamfered. Thereby, the nozzle 2 is easily press-fitted into the press-fitting hole 27 by tapering chamfering.

The nozzle holder 3 is formed in a cylindrical shape from a heat-resistant metal or synthetic resin. The nozzle holder 3 includes a press-fit fixing portion (large diameter portion) that is press-fitted into the inner peripheral surface (hole wall surface of the press-fit hole 19) of the nozzle holder of the valve body 1, and an inner peripheral surface (press-fit hole) of the nozzle holder of the valve body 1. A thick portion (small diameter portion) where an annular gap is formed, and a tapered or R-shaped step connecting the large diameter portion and the small diameter portion. Thereby, the nozzle holder 3 is easily press-fitted into the press-fitting hole 19 by the inclination of the step.
The nozzle holder 3 is integrally formed with an annular wall 49 that functions as a restricting portion that restricts the press-fitting and fixing position of the nozzle 2.
The nozzle holder 3 is fixed at a predetermined press-fit fixing position of the nozzle holder by being locked to the annular wall 46 of the valve body 1. Further, the nozzle 2 is fixed at a predetermined press-fitting and fixing position of the nozzle holder 3 by being locked to the annular wall 49 of the nozzle holder 3.

Next, the details of the shaft valve of the present embodiment will be briefly described with reference to FIGS. The shaft valve is formed in a predetermined shape from a heat-resistant metal. This shaft valve is an integral part in which the shaft 4 and the valve 5 are integrated.
The shaft 4 is rotatably or slidably accommodated in the accommodating hole 21 of the valve body 1 and the bearing hole 24 of the bearing holder 10 of the bearing device. The shaft 4 includes first and second projecting portions 51 and 52 on both sides in the rotation axis direction.
Between the first and second projecting portions 51 and 52, an axial portion (sliding portion) disposed in the bearing hole 24 of the bearing holder 10 is provided.
The first protrusion 51 is provided on one end side of the shaft 4 in the rotation axis direction, and protrudes from the sliding part through the insertion hole 26 into the flow path holes 14 to 17. The first protruding portion 51 has an outer diameter smaller than that of the second protruding portion 52 and the axial direction portion.
The second projecting portion 52 is provided on the other end side of the rotation axis direction of the shaft 4 and projects from the sliding portion toward the inside of the storage chamber 20. A valve gear plate 53 is fixed to the second projecting portion 52 for coupling with the valve gear 7 of the speed reduction mechanism.
A frustoconical (tapered) inclined surface is formed between the first projecting portion 51 and the axial portion. Further, the corners (edges) of the second protrusions 52 are tapered chamfered. Thereby, the bearing device (double ball bearings 11 and 12, oil seal 13) can be easily press-fitted and fixed to the outer periphery of the axial direction portion of the shaft 4.

The valve 5 is rotated in the operable range from the fully closed position to the fully open position, thereby changing the opening area of the flow path holes 14 to 18 to adjust the EGR rate.
The valve 5 passes through the central portion of the valve 5 in the valve body 1 and extends straight in the axial direction of the shaft 4 of the shaft valve (the rotation axis of the shaft 4 of the shaft valve) by a predetermined inclination angle. Is a disc-shaped swash plate that is integrally formed on the distal end side of the first protrusion 51 of the shaft 4 and is configured by a plate valve that extends radially about the central axis of the central portion of the valve 5. Has been.
An annular seal ring groove 28 is continuously formed in the circumferential direction on the outer peripheral end surface of the valve 5. That is, the seal ring groove 28 is provided around the entire outer periphery (entire periphery) of the outer peripheral end surface of the valve 5. The seal ring 6 is fitted in the seal ring groove 28.

The seal ring 6 is formed in a C shape from a heat resistant metal. The seal ring 6 has an outer peripheral side end projecting radially outward from the outer peripheral end surface of the valve 5, and an inner peripheral side end within the seal ring groove 28 in the radial direction, axial direction and circumferential direction. The seal ring groove 28 is fitted and held so as to be movable in the direction.
In addition, an outer peripheral surface (sliding portion) that can be in close contact with the valve seat surface 29 of the nozzle 2 fitted and held in the nozzle holder of the valve body 1 is provided on the outer end surface in the radial direction of the seal ring 6. It has been. Tapered or R-shaped chamfering may be applied to both edges in the axial direction of the sliding portion of the seal ring 6 so that the valve 5 can be easily opened and closed.
Therefore, the EGRV of this embodiment uses the tension in the radial direction (diameter expansion direction) orthogonal to the axial direction of the seal ring 6 fitted in the seal ring groove 28 of the valve 5 when the engine is stopped or EGR cut. Thus, the gap formed between the inner diameter surface (valve seat surface 29) of the nozzle 2 and the outer peripheral end surface of the valve 5 is sealed (sealed).

The actuator includes a motor that generates a driving force (torque) that rotationally drives the shaft 4 when supplied with electric power, and a speed reduction mechanism (power transmission mechanism) that decelerates the rotation of the motor by two steps and transmits the motor to the shaft 4 of the shaft valve. ).
The motor is housed and held in a motor housing recess of a motor housing formed integrally with the valve body 1.
The reduction mechanism includes three first to third reduction gears that rotate in conjunction with the motor shaft (motor output shaft) of the motor. These first to third reduction gears are composed of a pinion gear (motor gear) fixed to the motor shaft of the motor, an intermediate gear that meshes with the pinion gear and rotates, a valve gear 7 that meshes with the intermediate gear and rotates, and the like. Yes.

The valve gear 7 is integrally formed of synthetic resin or metal. A plurality of convex teeth (fan-shaped output gear teeth) meshing with the convex teeth of the intermediate gear are formed in a fan shape by a predetermined angle at the maximum outer diameter portion of the valve gear 7.
A metal valve gear plate 53 is insert-molded on the inner periphery of the valve gear 7. Thus, the valve gear 7 is fixed in a state in which the valve gear 7 is prevented from rotating around the second protrusion 52 of the shaft 4 via the valve gear plate 53.
The valve gear 7 includes a cylindrical boss portion 54 installed on the same axis as the first bearing sleeve 31 formed in the bearing holder 10 of the bearing device. On the outer peripheral side of the boss portion 54 of the valve gear 7, a spring seat portion 55 that locks the other end of the return spring 8 in the axial direction is provided.
The outer peripheral portion of the boss portion 54 has a function as a spring guide for guiding (holding) the coil inner diameter surface of the return spring 8.
However, the outer diameter of the boss 54 of the valve gear 7 is such that the coil of the return spring 8 when the valve gear 7 rotates by the maximum rotation angle and the return spring 8 is twisted in the rotational direction and contracted in the radial direction. Design with consideration of inner diameter shrinkage dimensions.

Here, a rotation angle sensor (EGR valve opening sensor) for detecting the rotation angle (valve opening of EGRV) of the valve 5 and the shaft 4 of the shaft valve is mounted on the inner peripheral portion of the valve gear 7.
The rotation angle sensor includes a pair of magnets (permanent magnets) 56 attached to the inner peripheral portion of the valve gear 7 and a Hall IC 57 attached to the sensor mounting portion of the sensor cover 9, and the output of the Hall IC 57 with respect to the rotation angle of the magnet 56. This is a rotation angle detection device that detects the rotation angle of the valve 5 by using change characteristics.
The sensor cover 9 is fastened and fixed to the flange 58 of the valve debo 1 by bolts 59.
Instead of the Hall IC 57, a non-contact type magnetic detection element such as a Hall element alone or a magnetoresistive element may be used.

Here, a motor that is a power source of the actuator is electrically connected to a battery mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by an ECU. The ECU is provided with a microcomputer having a well-known structure configured to include functions such as a CPU that performs control processing and arithmetic processing, various programs, and storage devices (memory such as ROM and RAM) that store various data. Yes.
The ECU includes an air flow meter, a crank angle sensor, an accelerator opening sensor, a throttle opening sensor, an EGR (valve) opening sensor, an intake air temperature sensor, a coolant temperature sensor, an exhaust gas sensor (air-fuel ratio sensor, oxygen concentration sensor), etc. Sensor output signals from various sensors are A / D converted by an A / D conversion circuit and then input to a microcomputer.
The microcomputer measures (calculates) the flow rate of EGR gas recirculated from the exhaust pipe of the engine to the intake pipe based on a sensor output signal (EGRV opening degree signal) output from the EGR opening degree sensor, and calculates the calculated EGR. The gas flow rate is used for various engine controls.

Next, details of the return spring 8 of this embodiment will be briefly described with reference to FIGS.
The return spring 8 is installed so as to surround the periphery of the boss portion 54 of the valve gear 7 and the periphery of the first bearing sleeve 31 of the bearing holder 10 in a spiral shape (spiral shape). The return spring 8 has a coil portion wound in a spiral between the spring seat portion 48 of the valve body 1 and the spring seat portion 55 of the valve gear 7.
The return spring 8 is a coil spring (biasing means) that generates an urging force (spring load, spring force) for urging the valve 5 in the valve closing operation direction with respect to the shaft 4 and the valve gear 7 of the shaft valve. The return spring 8 biases the valve 5 in a direction to return the valve 5 to the fully closed position (valve closing operation direction).
An annular first coil end portion that contacts the spring seat portion 48 of the valve body 1 is provided on one end side in the axial direction of the return spring 8.
An annular second coil end that contacts the spring seat 55 of the valve gear 7 is provided on the other end side in the axial direction of the return spring 8.

Next, the details of the bearing device of the present embodiment will be briefly described with reference to FIGS.
The bearing device is a shaft valve support device that rotatably supports a shaft valve, and includes a bearing holder 10, double ball bearings 11 and 12, and an oil seal 13. The bearing holder 10 is integrally formed by casting or metal injection molding a heat-resistant metal.
The bearing holder 10 is formed in a cylindrical shape whose one end surface and the other end surface (both end surfaces) in the axial direction are open. The bearing holder 10 has an opening 61 and an opening 62 through which the shaft 4 is inserted.
The opening 61 opens at one end face in the axial direction of the bearing holder 10 (the end face on the flow path side of the second annular wall 34), and flows through the valve body 1 through the insertion hole 26 opened at the partition wall 25 of the valve body 1. It is a circular insertion hole that allows the passage holes 14 to 18 to communicate with the bearing hole 24 of the bearing holder 10.
The opening 62 opens at the other end surface in the axial direction of the bearing holder 10 (the end surface on the housing chamber side of the first bearing sleeve 31), and communicates the housing chamber 20 of the valve body 1 and the bearing hole 24 of the bearing holder 10. It is a shape insertion hole.

The bearing holder 10 includes two first and second bearing sleeves 31 and 32 formed in a cylindrical shape, and first and second annular walls 33 and 34 formed in a cylindrical shape.
Tapered or R-shaped chamfering is applied to the corner (edge) of the bearing holder 10 on the tip side (flow channel hole side). Thereby, the bearing holder 10 is easily press-fitted into the press-fitting hole 23 by the inclination of the tip end side. The bearing holder 10 is press-fitted and fixed at a predetermined press-fitting and fixing position of the press-fitting hole 23 of the bearing sleeve 22 of the valve body 1.
Inside the two first and second bearing sleeves 31, 32, a bearing hole 24 that extends straight in the direction of the rotation axis of the shaft 4 is formed.

The outer peripheral portion of the first bearing sleeve 31 has a function as a spring guide that guides (holds) the coil inner surface of the return spring 8.
The first bearing sleeve 31 is disposed on the same axis as the boss portion 54 of the valve gear 7 of the speed reduction mechanism, and is disposed facing the boss portion 54 of the valve gear 7 with a predetermined distance therebetween. However, the outer diameter of the first bearing sleeve 31 is such that the inner diameter of the coil of the return spring 8 when the valve gear 7 rotates by the maximum rotation angle and the return spring 8 is twisted in the rotational direction and contracted in the radial direction. Design with shrinkage dimensions in mind.
A first press-fitting hole 35 into which the inner rings 41 of the double ball bearings 11 and 12 are press-fitted is formed on the inner periphery of the first bearing sleeve 31. The outer diameter of the first bearing sleeve 31 is smaller than the hole diameter of the receiving hole 21 of the valve body 1 and the outer diameter of each outer ring 42 of the double ball bearings 11 and 12, and the press-fitting hole of the bearing sleeve 22 of the valve body 1. It is larger than the inner diameter of 23.

The outer peripheral portion of the second bearing sleeve 32 has a function as a press-fit fixing portion that is press-fitted and fixed into the press-fit hole 23 of the bearing sleeve 22 of the valve body 1.
A second press-fitting hole 36 into which the cylindrical portion 45 of the oil seal 13 is press-fitted is formed on the inner peripheral surface of the second bearing sleeve 32. The outer diameter of the second bearing sleeve 32 is smaller than the outer diameter of the cylindrical portion 45 of the oil seal 13.
The first annular wall 33 is provided at a connecting portion that connects the first bearing sleeve 31 and the second bearing sleeve 32 in an L shape, and is directed radially inward from an intermediate portion of the first bearing sleeve 31. It is an annular inner peripheral convex portion that protrudes and can lock the outer ring 42 of the double ball bearings 11 and 12. The first annular wall 33 is an annular first wall body that surrounds the periphery of the shaft 4 in the circumferential direction.
The second annular wall 34 protrudes inward in the radial direction from the end of the second bearing sleeve 32 on the flow path hole side, and can lock the first cylindrical portion 45 of the oil seal 13. It is an inner peripheral convex part. The second annular wall 34 is an annular second wall body that surrounds the periphery of the shaft 4 in the circumferential direction.

The double ball bearings 11, 12 include two steel balls (steel balls, rolling elements) 43 that roll between the raceway surface of the inner ring 41 and the raceway surface of the outer ring 42, and the inner ring 41 and the outer ring 42. Two lip seals (seal materials) mounted between the races and on both end sides in the axial direction from the steel balls 43, and two retainers for preventing the plurality of steel balls 43 from falling off. ing.
The double ball bearings 11, 12 are a plurality of bearings that rotatably support (shaft support) the shaft 4 of the shaft valve by rolling friction of a steel ball 43 disposed between the raceway surface of the inner ring 41 and the raceway surface of the outer ring 42. This is a rolling ball bearing. The double ball bearings 11 and 12 are provided so that the shaft 4 can slide in the rotational direction with respect to the valve body 1 and the bearing holder 10 in the housing hole 21 of the valve body 1 and the bearing hole 24 of the bearing holder 10. It is a bearing part to support.
The two retainers are provided with semicylindrical or hemispherical recesses at a predetermined interval in the circumferential direction. Further, instead of the steel balls 43, rolling elements such as rollers may be used. Further, instead of the two lip seals, a metal reinforcing material (attachment ring) may be used.

Each inner ring 41 of the double ball bearings 11 and 12 is formed in an annular shape from a metal material, and has a spherical annular groove on the raceway surface (outer peripheral surface) facing the outer ring 42. The inner ring 41 constitutes a press-fit fixing portion (first outer ring portion) that is hermetically press-fitted and fixed to the outer periphery of the shaft 4 of the shaft valve. The inner ring 41 is an inner race that is coupled to the shaft 4 so as to be integrally rotatable.
Each outer ring 42 of the double ball bearings 11 and 12 is formed in an annular shape from the same metal material as the inner ring 41, and a spherical annular groove is formed on the raceway surface (inner circumferential surface) facing the inner ring 41. have. The outer ring 42 constitutes a press-fit fixing portion that is hermetically press-fitted and fixed to the first press-fit hole 35 of the bearing holder 10. The outer ring 42 is an outer race fixed to the bearing holder 10 so as not to rotate.

The oil seal 13 is an annular elastic body made of synthetic rubber reinforced by, for example, a metal reinforcing ring. The oil seal 13 is a seal member having an oil seal function that liquid-tightly seals an annular gap formed between the outer periphery of the shaft 4 of the shaft valve and the inner periphery of the second bearing sleeve 32 of the bearing holder 10. is there. The oil seal 13 is a seal member having a gasket function for hermetically sealing an annular gap formed between the outer periphery of the shaft 4 of the shaft valve and the inner periphery of the second bearing sleeve 32 of the bearing holder 10. .
The oil seal 13 is installed in the bearing hole 24 of the bearing holder 10 so as to surround the shaft 4 of the shaft valve in the circumferential direction. The oil seal 13 includes a seal lip 44 and a cylindrical portion (second outer ring portion) 45.
The seal lip 44 is in liquid-tight and air-tight contact with the sliding surface of the shaft 4.
The outer peripheral portion of the cylindrical portion 45 also functions as a press-fit fixing portion that is press-fit and fixed in a liquid-tight and air-tight manner into the second press-fit hole 36 of the second bearing sleeve 32 of the bearing holder 10.

[Assembly method of Example 1]
Next, an assembling method of the EGR gas flow rate control valve (EGRV) of this embodiment will be briefly described with reference to FIGS. 4 is a flowchart (process chart) showing the work sequence (first half) of the assembly process of the EGRV bearing device, and FIG. 5 shows the work sequence (second half) of the assembly process of the EGRV bearing device. It is the shown flowchart (process chart).

Here, FIG. 4A is a cross-sectional view showing an assembly process 1 for assembling the bearing holder 10 and the oil seal 13.
First, the oil seal 13 is press-fitted and fixed in the second press-fitting hole 36 provided in the inner periphery of the second bearing sleeve 32 of the bearing holder 10.
Specifically, an opening (an opening on the opposite flow path side) 62 on the outer side (accommodating chamber side) 62 of the first bearing sleeve 31 of the bearing holder 10 is provided on the flow path hole side of the second bearing sleeve 32 of the bearing holder 10. The oil seal 13 is inserted into the bearing hole 24 of the bearing holder 10 toward the opening 61 until the cylindrical portion 45 of the oil seal 13 comes into contact with the annular end surface (first regulating surface) of the second annular wall 34. The cylindrical portion 45 of the oil seal 13 is press-fitted into a second press-fitting hole 36 provided on the inner periphery of the second bearing sleeve 32 of the bearing holder 10. Thereby, the press-fit fixing position of the oil seal 13 with respect to the bearing holder 10 is regulated.

Here, FIG. 4B is a cross-sectional view showing an assembly process 2 for assembling the bearing holder 10 and the double ball bearings 11 and 12.
Next, the double ball bearings 11 and 12 are press-fitted and fixed in the first press-fitting hole 35 provided on the inner periphery of the first bearing sleeve 31 of the bearing holder 10.
Specifically, an opening (an opening on the opposite flow path side) 62 on the outer side (accommodating chamber side) 62 of the first bearing sleeve 31 of the bearing holder 10 is provided on the flow path hole side of the second bearing sleeve 32 of the bearing holder 10. The double ball bearings 11 and 12 are sequentially inserted into the bearing hole 24 of the bearing holder 10 toward the opening 61, and the outer ring 42 of the ball bearing 12 is connected to the annular end surface (second regulating surface) of the first annular wall 33. Until the outer ring 42 of the ball bearing 11 comes into contact with the outer ring 42 of the ball bearing 12, the double ball bearing 11 is inserted into the first press-fitting hole 35 provided on the inner periphery of the first bearing sleeve 31 of the bearing holder 10. , 12 are respectively press-fitted. Thereby, the press-fit fixing position of the double ball bearings 11 and 12 with respect to the bearing holder 10 is regulated.
The assembly of the bearing device is completed by the above assembly steps 1 and 2.

Here, FIGS. 4C and 4D are cross-sectional views showing assembly steps 3 and 4 for assembling the bearing device and the shaft valve.
Next, a bearing device (bearing holder 10, double ball bearings 11 and 12, oil seal 13) is press-fitted and fixed to the outer periphery of the axial direction portion (sliding portion) of the shaft 4 of the shaft valve.
Specifically, the bearing device is fitted from the second projecting portion side of the shaft 4 toward the sliding portion, and the inner rings 41 of the double ball bearings 11 and 12 are formed on the outer periphery of the axial portion of the shaft 4. Each of the seal lips 44 of the oil seal 13 is press-fitted. Thereby, the shaft valve is positioned and fixed with respect to the bearing holder 10 of the bearing device.
The assembly of the shaft subassembly is completed by the above assembly steps 3 and 4.

Here, FIG. 5E is a cross-sectional view showing an assembling step 5 for assembling the shaft subassembly and the valve body 1.
Next, the shaft subassembly is press-fitted and fixed in a press-fitting hole 23 provided in the inner periphery of the bearing sleeve 22 of the valve body 1.
Specifically, the valve body 1 passes through the insertion hole 26 of the valve body 1 from the opening on the outside of the valve body 1 (the opening on the opposite flow path side) toward the flow holes 14 to 17 of the valve body 1. The shaft subassembly is inserted into the receiving hole 21 of the bearing body 10, and the first and second bearing sleeves 31, 32 and the second annular wall 34 of the bearing holder 10 are annular end surfaces (third regulating surfaces) of the partition wall 25 of the valve body 1. The second bearing sleeve 32 of the bearing holder 10 is press-fitted into the press-fitting hole 23 provided in the inner periphery of the bearing sleeve 22 of the valve body 1 until it comes into contact with the bearing body 10.
Thereby, the press-fit fixing position of the shaft subassembly with respect to the housing (valve body 1) is regulated.

Here, FIG. 5 (f) is a cross-sectional view showing an assembling process 6 for assembling the nozzle 2 and the nozzle holder 3.
First, the nozzle 2 is press-fitted and fixed in a press-fitting hole 27 provided in the inner periphery of the nozzle holder 3. Next, the nozzle subassembly is press-fitted and fixed in a press-fitting hole 19 provided in the inner periphery of the nozzle holder of the valve body 1.
Specifically, the nozzle 2 is inserted into the press-fitting hole 27 of the nozzle holder 3 from the opening on the downstream side of the nozzle holder 3 toward the opening on the upstream side of the nozzle holder 3. The nozzle 2 is press-fitted into the press-fitting hole 27 provided on the inner periphery of the nozzle holder 3 until it comes into contact with the annular end surface (fourth regulating surface) of the annular wall 49.
Thereby, the press-fitting and fixing position of the nozzle 2 with respect to the nozzle holder 3 is regulated.
The assembly of the nozzle subassembly is completed by the above assembly process 6.

Here, FIG. 5G is a cross-sectional view showing an assembly process 7 for assembling the valve body 1, the nozzle 2 and the nozzle holder 3.
Next, from the opening on the upstream side of the valve body 1 (EGR gas introduction port) to the opening on the downstream side of the valve body 1 (EGR gas outlet port), it is inserted into the press-fitting hole 19 of the nozzle holder of the valve body 1. The nozzle subassembly is inserted, and press-fitting provided on the inner periphery of the nozzle holder of the valve body 1 until the annular wall 49 of the nozzle holder 3 comes into contact with the annular end surface (fifth regulating surface) of the annular wall 46 of the valve body 1 The nozzle holder 3 is press-fitted into the hole 19.
Thereby, the press-fitting and fixing position of the nozzle subassembly with respect to the housing (valve body 1) is regulated.
The assembly of the housing subassembly is completed by the above assembly process 7.

[Operation of Example 1]
Next, the operation of the EGR gas flow rate control valve (EGRV) of this embodiment will be briefly described with reference to FIGS.

The motor that rotationally drives the shaft valve of this embodiment is configured to be energized and controlled by the ECU.
Here, when electric power is not supplied to the motor, the valve 5 integrally formed on the shaft 4 is set to the fully closed position by the urging force (spring load) of the return spring 8.
At this time, the sliding portion of the seal ring 6 fitted in the seal ring groove 28 of the valve 5 is fitted and held in the nozzle holder of the valve body 1 by the tension (elastic deformation force) in the diameter increasing direction of the seal ring itself. In order to stick to the valve seat surface 29 of the nozzle 2, the sliding portion of the seal ring 6 comes into close contact with the valve seat surface 29 of the nozzle 2.
Therefore, the annular gap between the inner peripheral surface of the nozzle 2 and the outer peripheral end surface of the valve 5 is completely sealed. That is, the channel holes 14 to 18 formed in the valve body 1 are closed. Thereby, EGR gas does not mix in clean intake air (fresh air) that has passed through the air cleaner (EGR cut).

Next, when the operating condition (engine operating condition) is such that the EGRV is opened, the valve 5 is opened so as to open to a predetermined opening corresponding to the operating condition.
Then, electric power is supplied to the motor, and the motor shaft of the motor is rotated in the valve opening operation direction. Thereby, the rotational power (torque) of the motor is transmitted to the pinion gear, the intermediate gear, and the valve gear 7. Then, the shaft 4 of the shaft valve to which the torque is transmitted from the valve gear 7 rotates in the valve opening operation direction by a predetermined rotation angle (valve opening) as the valve gear 7 rotates.
As described above, by changing the EGRV valve opening by variably controlling the power supplied to the motor (drive current value or applied voltage value) in accordance with the engine operating condition, the air cleaner passed through the air cleaner. The introduction amount (mixing amount) of EGR gas with respect to the clean intake air is adjusted.
That is, the valve 5 is controlled to open to a valve opening corresponding to the control target value. That is, the channel holes 14 to 18 are opened.

Therefore, EGR gas, which is a part of the exhaust gas flowing out from the combustion chamber for each cylinder of the engine, passes from the exhaust passage (EGR gas branching portion) formed in the exhaust pipe to the inside of the EGR gas pipe (EGR) on the exhaust pipe side. Gas passage) → EGRV valve body 1 internal passage (EGR gas introduction port → passage holes 14 to 18 → EGR gas outlet port) → via the inside of the EGR gas pipe on the intake pipe side (EGR gas passage) Thus, it is recirculated to the intake passage (EGR gas merging portion) formed in the intake pipe. Therefore, EGR gas is mixed into the intake port and the intake air supplied to the combustion chamber for each cylinder of the engine.
As a result, harmful substances (for example, NOx) contained in the exhaust gas are reduced.

[Effect of Example 1]
As described above, in the EGRV of this embodiment, the bearing device that rotatably supports the shaft valve (the shaft 4 integrally formed with the valve 5) in the housing hole 21 of the valve body 1 and the bearing hole 24 of the bearing holder 10. By providing the double ball bearings 11 and 12 continuously arranged in the rotation axis direction of the shaft 4 and the oil seal 13 arranged on the flow path hole side from the double ball bearings 11 and 12. The gasket of the oil seal 13 prevents foreign matter such as fine particles contained in the EGR gas and welding spatter from entering the bearing device side (double ball bearing side) through the insertion hole 26 from the flow passage hole side of the valve body 1. It can be prevented by the function.
As a result, it is possible to prevent a malfunction of the shaft valve and a valve block associated with the entry of foreign matter from the flow path hole side of the valve body 1 to the bearing device side.

Further, since the double ball bearings 11 and 12 are adopted without using a metal bearing as the bearing device, the bearing device side (double ball) is assumed to pass through the insertion hole 26 from the flow passage hole side of the valve body 1. Even if foreign matter enters the bearing side), malfunction of the shaft valve and valve block can be prevented.
Further, since the double ball bearings 11 and 12 are continuously arranged in the direction of the rotation axis of the shaft 4, the shaft runout of the shaft 4 is equivalent to that of the conventional design. Even if the double ball bearings 11 and 12 are not arranged at a predetermined axial distance, the shaft runout of the shaft 4 is equivalent to that of the conventional design. ). As a result, the oil seal 13 can be disposed closer to the flow path hole than the double ball bearings 11 and 12.

  Further, the valve 5 accommodated rotatably (openable and closable) in the flow path holes 14 to 18 of the housing (the valve body 1 and the nozzle 2) is configured as an integral part with the shaft 4. Further, the valve 5 is formed integrally with the first protrusion 51 of the shaft 4. Thereby, the shaft 4 and the valve 5 are integrally formed, that is, a shaft valve subassembly. Thereby, the formation position and formation angle of the valve 5 with respect to the shaft 4 can be assembled with high accuracy. Further, since the shaft 4 and the valve 5 are integrally formed and the welding process between the shaft 4 and the valve 5 is abolished, weld spatter does not remain in the valve body 1. It is possible to prevent a malfunction of the shaft valve and a valve block caused by intrusion of foreign matter such as welding spatter from the side to the bearing device side.

Further, the partition wall 25 of the valve body 1 is formed with an insertion hole 26 into which the shaft 4 integrally formed with the valve 5 can be inserted. The insertion hole 26 is an elliptical hole or a circular hole having a hole diameter larger than the outer diameter of the valve 5 and smaller than the outer diameter of the bearing holder 10 as represented by the following equation (1). Moreover, the hole diameter of the insertion hole 26 is smaller than the hole diameter of the accommodation hole 21 of the valve body 1 and the hole diameter of the press-fit hole 23 as shown in the following equation (2). Further, the hole diameter of the insertion hole 26 is smaller than the hole diameter of the first press-fit hole 35 and the second press-fit hole 36 of the bearing holder 10 as shown in the following equation (3).
[Equation 1]
The outer diameter of the bearing holder 10> the hole diameter of the insertion hole 26> the outer diameter of the valve 5 [Equation 2]
Hole diameter of receiving hole 21> Hole diameter of press-fit hole 23> Hole diameter of insertion hole 26 [Equation 3]
The diameter of the first press-fit hole 35> the diameter of the second press-fit hole 36> the diameter of the insertion hole 26 When the outer diameter of the valve 5 is larger than the outer diameter of the bearing holder 10, the bearing sleeve 22 of the valve body 1. Since the press-fitting hole 23 is cut off at the outer peripheral portion of the valve 5, a gap is formed between the accommodation hole 21 of the valve body 1 and the outer peripheral surface of the first bearing sleeve 31 of the bearing holder 10. As a result, it is possible to solve the problem that the EGR gas flowing through the flow passage holes 14 to 18 of the housing (the valve body 1 and the nozzle 2) leaks out of the valve body 1 through the gap.

By the way, when the spring inner diameter holding portion is provided on the cylindrical boss portion integrally formed with the housing as in the conventional EGR gas flow control valve (EGRV), the bearing sleeve of the bearing device is provided in the accommodation hole 21 of the valve body 1. If it is configured to be press-fitted and fixed, the physique of the housing, in particular, the physique in the radial direction perpendicular to the rotation axis direction of the shaft becomes large.
However, as in the present embodiment, the first bearing sleeve 31 of the bearing holder 10 is provided with a function as a spring guide on the first bearing sleeve side of the bearing holder 10 that is press-fitted into the receiving hole 21 of the valve body 1. If the coil inner diameter surface of the return spring 8 is held, the spring inner diameter holding portion is provided on the cylindrical boss portion integrally formed with the housing as in the conventional EGR gas flow rate control valve (EGRV). The outer diameter of the return spring 8 is the same.
Therefore, the physique of EGRV can be reduced in size, and the mountability of EGRV in the engine room of a vehicle such as an automobile can be improved.

  FIG. 6 and FIG. 7 show Example 2 of the present invention. FIG. 6 is a flow work diagram (process chart) showing the work sequence (first half) of the assembly process of the EGRV bearing device. It is a flowchart (process chart) which showed the work sequence (second half) of the assembly | attachment process of the bearing apparatus of EGRV.

In the EGRV of the present embodiment, the shaft 4 and the valve 5 are configured as separate parts.
The shaft 4 includes an axial portion (sliding portion) disposed in the bearing hole 24 of the bearing holder 10 and first and second projecting portions 51 and 52 disposed on both sides of the axial portion. Yes.
In addition, the 1st protrusion part 51 has an outer diameter smaller than the 2nd protrusion part 52 and an axial direction part. Further, a truncated cone-shaped (tapered) inclined surface is formed between the first projecting portion 51 and the axial direction portion. Thereby, the bearing device (oil seal 13) can be easily press-fitted and fixed to the outer periphery of the axial direction portion of the shaft 4.
Further, the corners (edges) of the second protrusions 52 are tapered chamfered. Thereby, the bearing device (double ball bearings 11, 12) can be easily press-fitted and fixed to the outer periphery of the axial direction portion of the shaft 4.

The valve 5 is welded and fixed to one end portion (first projecting portion 51) in the rotation axis direction of the shaft 4 using welding means such as arc welding (TIG welding, resistance welding) or laser welding.
One side surface (one end surface) of the valve 5 in the plate thickness direction, for example, when the valve 5 is fully closed (when the opening degree of the valve 5 is set to a fully closed posture in which the flow path holes 14 to 18 are fully closed). ), A fitting groove 71 which is a coupling portion (welding fixing portion) to the shaft 4 is formed on the downstream end surface located on the downstream side in the EGR gas flow direction. The fitting groove 71 is opened at one end surface of the valve 5 and is a fitting recess (inclined by a predetermined inclination angle with respect to the surface direction of the one end surface of the valve 5 from the opening side to the back side. The shaft attachment portion to which the shaft 4 of the shaft valve is attached. The fitting groove 71 is press-fitted and fixed to the first protrusion 51 of the shaft 4 of the shaft valve.

Here, FIGS. 6A and 6B are cross-sectional views showing assembly steps 1 and 2 for assembling the bearing holder 10 and the oil seal 13.
First, as in the first embodiment, the oil seal 13 is press-fitted and fixed in the second press-fit hole 36 provided on the inner periphery of the second bearing sleeve 32 of the bearing holder 10. Thereby, the press-fit fixing position of the oil seal 13 with respect to the bearing holder 10 is regulated.

Here, FIGS. 6C and 6D are sectional views showing the assembling steps 3 and 4 for assembling the shaft 4 and the double ball bearings 11 and 12.
Next, the double ball bearings 11 and 12 are press-fitted and fixed to the outer periphery of the axial portion (sliding portion) of the shaft 4.
Specifically, the double ball bearings 11 and 12 are sequentially fitted from the second projecting portion side of the shaft 4 to the sliding portion, and the double ball bearings 11 and 12 are disposed on the outer periphery of the axial direction portion of the shaft 4. Each of the 12 inner rings 41 is press-fitted. Thereby, the double ball bearings 11 and 12 are positioned and fixed with respect to the shaft 4.

Here, FIGS. 6E and 6F are cross-sectional views showing assembly steps 5 and 6 for assembling the shaft 4 and the bearing device.
Next, the double ball bearings 11 and 12 assembled to the shaft 4 are press-fitted and fixed in the first press-fitting holes 35 provided on the inner periphery of the first bearing sleeve 31 of the bearing holder 10.
Specifically, an opening (an opening on the opposite flow path side) 62 on the outer side (accommodating chamber side) 62 of the first bearing sleeve 31 of the bearing holder 10 is provided on the flow path hole side of the second bearing sleeve 32 of the bearing holder 10. The double ball bearings 11 and 12 integrated with the shaft 4 are sequentially inserted into the bearing hole 24 of the bearing holder 10 toward the opening 61, and the outer ring 42 of the ball bearing 12 is the annular end surface of the first annular wall 33. The first press-fitting hole provided on the inner periphery of the first bearing sleeve 31 of the bearing holder 10 until the outer ring 42 of the ball bearing 11 contacts with the outer ring 42 of the ball bearing 12 until the outer ring 42 contacts with the (second regulating surface). The outer rings 42 of the double ball bearings 11 and 12 integrated with the shaft 4 are press-fitted into the shaft 35. Thereby, the press-fit fixing position of the shaft 4 and the double ball bearings 11 and 12 with respect to the bearing holder 10 is regulated.
The assembly of the shaft subassembly is completed by the above assembly steps 5 and 6.

Here, FIGS. 7G and 7H are cross-sectional views showing assembly steps 7 and 8 for assembling the shaft subassembly and the valve 5.
Next, the fitting groove 71 of the valve 5 is press-fitted into the first protrusion 51 of the shaft 4.
Next, the valve 5 is fixed to the shaft 4 by bringing the valve 5 into contact with the first protruding portion 51 of the shaft 4 using arc welding (TIG welding, resistance welding).
Next, FIG. 7 (i) is an assembly process diagram showing an assembly process 9 for assembling the shaft subassembly and the valve body 1.
Thereby, the press-fit fixing position of the shaft subassembly with respect to the housing (valve body 1) is regulated.
Next, FIG. 7 (j) is an assembly process diagram showing the assembly process 10 for assembling the nozzle 2 and the nozzle holder 3.
The assembly of the nozzle subassembly is completed by the above assembly process 10.
Next, FIG. 7 (k) is an assembly process diagram showing an assembly process 11 for assembling the valve body 1, the nozzle 2, and the nozzle holder 3.
The assembly of the housing subassembly is completed by the above assembly process 11.

As described above, the EGRV of the present embodiment can achieve the same effect as that of the first embodiment.
Further, the valve 5 accommodated in the flow passage holes 14 to 18 of the housing (the valve body 1 and the nozzle 2) so as to be rotatable (openable and closable) is configured as a separate part with respect to the shaft 4.
The valve 5 is assembled to the first protrusion 51 of the shaft 4. Specifically, before the shaft 4 is assembled so as to protrude from the accommodation hole 21 of the valve body 1 into the flow path holes 14 to 18, the shaft 4 and the valve 5 are assembled by welding fixation. That is, in the EGRV of this embodiment, the shaft 4 and the valve 5 are integrated (shaft valve subassembly) by post-assembly.
Thereby, the formation position and formation angle of the valve 5 with respect to the shaft 4 can be assembled with high accuracy. Further, since welding spatter does not remain in the valve body 1 when the shaft 4 and the valve 5 are welded and fixed, the bearing body side (double ball bearing side) from the flow hole side of the valve body 1 through the insertion hole 26. It is possible to prevent a malfunction or a valve block of the shaft 4 provided with the valve 5 due to the intrusion of foreign matter such as welding spatter.

Further, since the shaft 4 and the valve 5 are assembled by welding and fixing before the shaft 4 is assembled so as to protrude from the accommodation hole 21 of the valve body 1 into the flow path holes 14 to 18, the shaft 4 and the valve 5 When the nozzle sub-assembly (nozzle 2 and nozzle holder 3) is press-fitted and fixed to the press-fitting hole 19 formed in the inner periphery of the nozzle holder of the valve body 1 before the assembly work of Even when the nozzle subassembly is attached to the press-fitting hole 19, no welding spatter remains in the housing (or valve body).
Therefore, foreign matter such as welding spatter can be avoided between the valve seat surface 29 of the nozzle 2 and the sliding portion of the seal ring 6, thereby preventing sliding failure between the nozzle 2 and the seal ring 6. be able to.

Further, since the shaft 4 and the valve 5 are assembled by welding and fixing before the shaft 4 is assembled so as to protrude from the accommodation hole 21 of the valve body 1 into the flow path holes 14 to 18, the shaft 4 and the valve 5 In the case where the nozzle subassembly (nozzle 2 and nozzle holder 3) is later press-fitted and fixed to the press-fitting hole 19 formed in the inner periphery of the nozzle holder of the valve body 1, rather than the assembly work of FIG. Even when a nozzle subassembly is retrofitted to the valve body 1, foreign matter such as welding spatter can be prevented from adhering to the hole wall surface (valve seat surface 29) of the press-fitting hole 19 of the valve body 1. The problem that the nozzle subassembly cannot be press-fitted and fixed to 19 can be solved.
Therefore, since the nozzle subassembly can be easily assembled in the press-fitting hole 19 of the valve body 1, the productivity of EGRV can be improved.

[Modification]
In this embodiment, the nozzle subassembly is press-fitted and fixed in the press-fitting hole 19 provided in the inner periphery of the nozzle holder of the valve body 1, but the nozzle 2 is inserted in the press-fitting hole 19 provided in the inner periphery of the nozzle holder of the valve body 1. May be press-fitted and fixed directly. In this case, the nozzle holder 3 separate from the nozzle holder of the valve body 1 is not required, and the number of parts and the number of assembling steps can be reduced.
As a spring (valve urging means), a return spring that urges the shaft valve or the shaft 4 and the valve 5 in the valve closing operation direction, and an over spring that urges the shaft valve or the shaft 4 and the valve 5 in the valve opening operation direction. A coil spring provided with a turn spring and a U-shaped hook portion formed by bending the coupling portion of the return spring and the overturn spring into an inverted U shape may be employed.

  In this embodiment, as an actuator that rotationally drives the shaft 4 to open and close the valve 5, a motor that generates torque upon receipt of electric power and a speed reduction mechanism (power transmission mechanism) that decelerates the rotation of the motor are provided. Although an electric actuator is adopted, a negative pressure actuated actuator driven by a negative pressure from an electric vacuum pump via a negative pressure control valve as an actuator for rotating and driving the shaft 4 to open and close the valve 5; You may employ | adopt the linear solenoid (electromagnetic actuator) provided with the electromagnet containing a coil.

In the present embodiment, the present invention is applied to the EGR gas flow rate control valve (EGRV), but a low-temperature exhaust gas passage communicating with the outlet side of the EGR cooler and a bypass passage (high-temperature exhaust gas) bypassing the EGR gas from the EGR cooler. The present invention is applied to other exhaust gas control valves such as an exhaust gas flow path switching valve that switches between a flow path and an exhaust gas flow rate (pressure) control valve installed in an engine exhaust pipe (turbine housing of a turbocharger). You may do it.
Examples of the exhaust gas control valve include a waste gate valve, a scroll switching valve, an exhaust flow control valve, an exhaust pressure control valve, and an exhaust switching valve.
In addition, although a butterfly valve is employed as a valve constituting the valve body of the exhaust gas control valve, a rotary valve such as a flap valve, a plate valve, or a rotary valve may be employed.
Further, as the internal combustion engine (engine), a multi-cylinder gasoline engine may be used instead of the multi-cylinder diesel engine. Moreover, you may apply to a single cylinder engine.

1 Valve body (housing)
2 Nozzle (housing)
3 Nozzle holder (housing)
4 Shaft 5 Valve 6 Seal ring 7 Valve gear 8 Return spring 10 Bearing holder (bearing device)
11 Ball bearing (bearing device)
12 Ball bearing (bearing device)
13 Oil seal (bearing device)
14 Channel hole 15 Channel hole 16 Channel hole 17 Channel hole 18 Channel hole 20 Accommodating chamber 21 Accommodating hole 22 Bearing sleeve 23 Press-fit hole 24 Bearing hole 25 Bulkhead 26 Insertion hole 27 Press-in hole 31 First bearing sleeve (outside Ring)
32 Second bearing sleeve (outer ring)
33 1st ring wall (1st regulation part)
34 Second ring wall (second regulating part)
35 1st press-fit hole 36 2nd press-fit hole 41 Inner ring 42 Outer ring (first outer ring part)
43 Steel ball 44 Seal lip 45 Cylindrical part (second outer ring part)

Claims (17)

(A) a flow path through which exhaust gas passes, and a housing having a receiving hole opened in the wall surface of the flow path;
(B) a valve housed in the flow path to open and close the flow path;
(C) a shaft accommodated in the accommodation hole and provided with the valve;
(D) In an exhaust gas control valve including a bearing device that is accommodated in the accommodation hole and rotatably supports the shaft,
The bearing device has a plurality of rolling bearings arranged continuously in the rotation axis direction of the shaft, and an exhaust gas control characterized in that a gasket is arranged on the flow path side of these rolling bearings. valve. The exhaust gas control valve according to claim 1,
The accommodation hole has two first and second press-fitting holes that are arranged at a predetermined distance in the rotation axis direction of the shaft and are formed on the same axis as the accommodation hole. Exhaust gas control valve. The exhaust gas control valve according to claim 2,
The plurality of rolling bearings have a first outer ring portion that is press-fitted and fixed in the first press-fitting hole,
The exhaust gas control valve according to claim 1, wherein the gasket has a second outer ring portion that is press-fitted and fixed in the second press-fitting hole. The exhaust gas control valve according to any one of claims 1 to 3,
The exhaust gas control valve according to claim 1, wherein the shaft is installed so as to penetrate the accommodation hole in a direction of a center line thereof. In the exhaust gas control valve according to any one of claims 1 to 4,
The exhaust gas control valve according to claim 1, wherein the shaft has a projecting portion projecting into the flow path on one end side in the rotation axis direction. The exhaust gas control valve according to claim 5,
The valve is composed of an integral part with the shaft,
The exhaust gas control valve, wherein the protrusion is integrally formed with the valve. The exhaust gas control valve according to claim 5,
The valve is configured as a separate part with respect to the shaft,
The exhaust gas control valve, wherein the protrusion is assembled with the valve. The exhaust gas control valve according to any one of claims 1 to 7,
The exhaust gas control valve according to claim 1, wherein the bearing device includes a cylindrical holder configured to be separated from the housing and holds the plurality of rolling bearings and the gasket. The exhaust gas control valve according to claim 8,
The holder has a bearing hole extending in a rotation axis direction of the shaft;
The housing communicates the bearing hole and the flow path, and has an insertion hole into which the shaft can be inserted.
The exhaust gas control valve according to claim 1, wherein the insertion hole is larger than an outer diameter of the valve and smaller than an outer diameter of the holder. The exhaust gas control valve according to any one of claims 1 to 9,
An exhaust gas control valve comprising a spring that applies a load to the shaft in a valve closing operation direction or a valve opening operation direction. The exhaust gas control valve according to claim 10,
The bearing device has a cylindrical bearing sleeve arranged to surround the shaft in the circumferential direction;
The spring has a coil that spirally surrounds the bearing sleeve,
The exhaust gas control valve according to claim 1, wherein the bearing sleeve includes a press-fit portion that is press-fitted and fixed in the accommodation hole, and a spring guide that holds a coil inner diameter surface of the spring. The exhaust gas control valve according to any one of claims 1 to 11,
The plurality of rolling bearings are a plurality of ball bearings that rotatably support the shaft with respect to the housing in the housing hole. The exhaust gas control valve according to any one of claims 1 to 12,
The exhaust gas control valve according to claim 1, wherein the gasket is an oil seal that seals an annular gap formed on an outer peripheral side of the shaft. The exhaust gas control valve according to any one of claims 1 to 13,
The housing is configured by a valve body having a press-fitting hole formed on the same axis as the flow path, and a separate part with respect to the valve body, and the tubular shape in which the flow path is formed. A nozzle,
The exhaust gas control valve, wherein the nozzle is press-fitted and fixed in the press-fitting hole. The exhaust gas control valve according to claim 14,
A seal ring for sealing an annular gap formed between a circumferential wall surface of the nozzle and a circumferential end surface of the valve when the valve is fully closed;
The exhaust gas control valve according to claim 1, wherein the valve has an annular groove for mounting the seal ring on the entire circumference of the circumferential end face. In the assembly method of the exhaust gas control valve according to claim 14 or 15,
Assembling the bearing device to a shaft valve formed integrally with the valve on the shaft to form a shaft valve subassembly;
Next, assembling the shaft valve subassembly in the accommodation hole;
And a step of press-fitting and fixing the nozzle into the press-fitting hole to form a housing subassembly. In the assembly method of the exhaust gas control valve according to claim 14 or 15,
Assembling the bearing device to the shaft to form a shaft subassembly;
Next, assembling the valve to the shaft subassembly to form a shaft valve subassembly;
Next, assembling the shaft valve subassembly in the accommodation hole;
And a step of press-fitting and fixing the nozzle into the press-fitting hole to form a housing subassembly.

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