JP2006183635A - Exhaust gas valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent entrance of moisture, dust and the like into a drive part and to prevent adhesion of moisture to a guide member holding a valve body. <P>SOLUTION: The drive part 14 formed in a valve base section 12 is connected with a diaphragm 60 connected to the valve body 16. The drive part 14 is supplied with negative pressure fluid and thereby the valve body 16 is displaced along an axial direction. The drive part 14 includes a first casing 26 connected to an upper part of the valve base section 12. A side surface of the first casing 26 is formed with a plurality of air windows 52 spaced at predetermined distances along a circumferential direction and a plurality of drain holes 58 are formed in a lower part of the first casing 26 connected to the valve base section 12 along the circumferential direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust gas valve, and more particularly, to an exhaust gas valve capable of preventing moisture and the like from entering a drive portion of the exhaust gas valve.

  Conventionally, for example, an exhaust gas valve has been used to remove harmful components discharged from an internal combustion engine. The exhaust gas valve recirculates the exhaust gas discharged from the internal combustion engine to the intake system, and reduces harmful components such as NOx contained in the exhaust gas, so that the intake system and the exhaust system of the internal combustion engine are reduced. Have the function of communicating with

  For example, such an exhaust gas valve includes a housing having an exhaust gas passage for communicating an intake system and an exhaust system of an internal combustion engine, a valve for switching the communication state of the exhaust gas passage, and a pressure fluid supply action. And a drive unit including a diaphragm for displacing the valve along the axial direction. In the drive unit, a peripheral portion of a diaphragm is sandwiched between an upper case and a lower case, and a negative pressure fluid is supplied into the upper case, whereby the valve is displaced along the axial direction through the diaphragm. I am letting.

  The lower case is formed with a plurality of openings in the lower part connected to the housing, and the inside and the outside of the lower case communicate with each other (for example, see Patent Document 1).

JP-A-8-319903

  By the way, in the prior art which concerns on patent document 1, since several opening part is formed in the lower part of the lower case used as the vicinity of a housing, when attaching the valve | bulb for exhaust gas to a vehicle, for example, the said vehicle There is a concern that moisture, dust, and the like from the road surface may enter through the opening during traveling. Then, when moisture or dust enters the inside of the lower case, the moisture or dust adheres to a bush or the like that is kept airtight between the valve and the housing, which may hinder the displacement of the valve. It is done.

  The present invention has been made in consideration of the above-described problems, and prevents moisture and dust from entering the drive unit and prevents moisture from adhering to the guide member that holds the valve body. It is an object to provide a simple exhaust gas valve.

In order to achieve the above object, the present invention provides a valve base having a circulation passage for exhaust gas and a valve seat provided in the circulation passage.
A valve body that opens and closes the circulation passage by being seated and separated from the valve seat;
A guide member that is provided inside the valve base and holds the valve body in an axially displaceable manner;
A drive unit having a casing connected to the valve base, and displacing the valve body along an axial direction;
An opening hole formed on a side surface of the casing so as to be in a direction away from the valve base portion along the axial direction with respect to the guide member, and communicating the inside and the outside of the casing;
It is characterized by providing.

  According to the present invention, the opening hole formed in the side surface of the casing in the drive unit is arranged in a direction away from the valve base part from the guide member, and the inside and the outside of the casing are communicated by the opening hole. Therefore, by arranging the opening hole above the casing in this way, it is possible to suppress the entry of moisture, dust, etc. from below in the exhaust gas valve through the opening hole. It is possible to prevent the valve body from adhering to the guide member that holds the valve body along the axial direction.

  Further, when the temperature inside the casing rises due to the exhaust gas flowing through the valve base, heat can be radiated through the opening hole, and the inside of the casing can be cooled to lower the temperature.

  Furthermore, by forming a drain hole in the end connected to the valve base in the casing, for example, even when moisture enters the inside of the casing from the opening hole, the drain hole becomes the valve base of the casing. Since it forms in the lower part used as the side, after the said water | moisture content falls below, it is discharged | emitted suitably outside through a drain hole. Therefore, moisture does not accumulate in the lower part of the casing, and the moisture can be prevented from adhering to a guide member or the like that holds the valve body.

  Furthermore, when the first body connected to the valve base in the casing and the second body disposed in the upper portion along the axial direction of the first body are caulked in the opening hole, the displacement of the casing It is preferable to insert a positioning jig that regulates the above. Thereby, the displacement to the axial direction and circumferential direction of a casing at the time of caulking formation of the 1st and 2nd body via a positioning jig can be controlled. Therefore, it is not necessary to separately form a hole for positioning the casing, and the casing can be positioned using an opening hole for cooling the inside of the casing.

  According to the present invention, the following effects can be obtained.

  That is, an opening hole formed in the side surface of the casing in the drive unit is disposed in a direction away from the valve base with respect to the guide member, and the inside and outside of the casing are communicated with each other by the opening hole. It is possible to suppress the entry of moisture, dust and the like from below in the valve for use through the opening hole, and it is possible to prevent the moisture and the like from entering the casing and adhering to the guide member holding the valve body.

  A preferred embodiment of an exhaust gas valve according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 denotes an exhaust gas that circulates exhaust gas exhausted from an exhaust system of an internal combustion engine to the intake system of the internal combustion engine again as an exhaust gas valve according to the first embodiment of the present invention. Indicates a recirculation valve.

  As shown in FIG. 1, the exhaust gas recirculation valve 10 has a passage for recirculating exhaust gas discharged from the exhaust system Ex (see FIG. 4) of the internal combustion engine to the intake system In (see FIG. 4). A base 12; a drive unit 14 connected to an upper portion of the valve base 12 and supplied with a pressure fluid from a pressure fluid supply source (not shown) (for example, a vacuum pump); and an exhaust gas under the drive action of the drive unit 14 It consists of a valve body 16 that switches the communication state between each other.

  The valve base 12 is formed with an inlet port (not shown) connected to the exhaust system Ex of the internal combustion engine at a substantially central portion of the lower surface, and at the side of the valve base 12 spaced from the inlet port, An outlet port (not shown) connected to the intake system In of the engine is formed. The inlet port and the outlet port are communicated with each other by a valve chamber (not shown) defined on the upper side of the inlet port.

  An annular valve seat (not shown) facing the valve chamber is disposed in the valve chamber, and a valve portion (not shown) of the valve body 16 is in contact with the valve seat.

  On the other hand, the valve base portion 12 is provided with a guide member 18 formed of a sintered material such as a carbon sintered body in an opening portion opened upward of a valve chamber (not shown). A diameter-expanded portion 20 that is expanded in the radially outward direction is engaged with the opening.

  A guide hole 22 penetrating along the axial direction is formed in a substantially central portion of the guide member 18, and the valve shaft portion 24 of the valve body 16 is inserted into the guide hole 22. The valve shaft portion 24 of the valve body 16 is supported by the guide hole 22 so as to be displaceable along the axial direction.

  One end of the guide member 18 bulges so as to engage with the convex portion 28 of the first casing (first body) 26 of the driving portion 14, and an annular concave portion 30 that is recessed so as to face the guide hole 22. Is formed. An annular seal member 32 is mounted in the annular recess 30 so as to be coaxial with the guide hole 22.

  The seal member 32 is formed of, for example, an elastic material such as rubber, and the valve shaft portion 24 of the valve body 16 is inserted through a substantially central portion thereof.

  On the other hand, a gasket 34 formed in a plate shape from a metal material is sandwiched between the enlarged diameter portion 20 of the guide member 18 and a first casing 26 (described later) in the drive portion 14. Thus, by providing the gasket 34, the exhaust gas flowing through the valve base 12 can be prevented from leaking from between the enlarged diameter portion 20 of the guide member 18 and the valve base 12, and the valve base. 12 can be kept airtight.

  On the other hand, a ring member 36 formed in an annular shape from a metal material is provided between the gasket 34 and the enlarged diameter portion 20 of the guide portion.

  The drive unit 14 is provided at the top of the valve base 12 and the guide member 18 and has a first casing 26 formed in a bottomed shape, and a second casing (second body) mounted on the top of the first casing 26. 38, a pilot port 40 provided on the side of the second casing 38 and supplied with pressure fluid from a pressure fluid supply source (not shown), and provided between the first casing 26 and the second casing 38, And a driving mechanism 42 that is displaced by the pressure fluid.

  The first casing 26 is formed in a curved concave shape that opens upward, and one end portion of the guide member 18 is engaged with a convex portion 28 formed in a substantially central portion. Further, a bolt hole 44 spaced apart from the convex portion 28 in the radial direction by a predetermined distance along the circumferential direction is formed, and the annular plate member 46 disposed above the bolt hole 44 and the bolt hole 44. A plurality of bolts 48 are inserted through the. The first casing 26 is fixed to the valve base 12 by screwing the bolt 48 into the screw hole 50 of the valve base 12. That is, the first casing 26 is sandwiched between the plate member 46 and the valve base 12.

  Further, as shown in FIG. 2, a plurality of (for example, three) air windows (opening holes) 52 spaced apart from each other by a predetermined distance along the circumferential direction are formed on the side surface of the first casing 26. The inside and the outside of the first casing 26 communicate with each other through an air window 52 formed in a rectangular shape. Therefore, when the temperature inside the first casing 26 rises due to the influence of the exhaust gas flowing through the valve base 12, heat can be radiated through the air window 52, and the inside of the first casing 26 is cooled to the temperature. Can be reduced.

  The air window 52 is provided on the upper side near the second casing 38 on the side of the first casing 26, so that when the vehicle on which the exhaust gas recirculation valve 10 is mounted travels from below. The muddy water, dust and the like can be prevented from entering through the air window 52. Specifically, the air window 52 is formed on the upper side (in the direction of arrow A) from the substantially central portion along the axial direction (in the directions of arrows A and B) of the first casing 26. It is possible to prevent moisture, dust, and the like from adhering to the seal member 32 provided above the convex portion 28 and provided inside the convex portion 28.

  Further, when the flange portion 54a of the first casing 26 and the flange portion 54b of the second casing 38, which will be described later, are caulked (for example, rolling caulking), the air window 52 is positioned as shown in FIG. A jig (positioning jig) 56 is inserted from the outer peripheral side of the first casing 26. Thereby, the displacement of the first casing 26 is restricted in the axial direction and the circumferential direction via the positioning jig 56. That is, the air window 52 also functions as a fixing hole into which the positioning jig 56 is inserted when the first casing 26 and the second casing 38 are caulked.

  On the other hand, as shown in FIGS. 1 and 2, a plurality of (for example, four) drain holes (drain holes) are provided in the lower portion of the first casing 26 so as to straddle the lower surface and side surfaces of the first casing 26. 58) is formed. The drain holes 58 are formed at predetermined intervals along the circumferential direction of the first casing 26, and the inside and the outside of the first casing 26 communicate with each other through the drain holes 58. Thereby, for example, even when moisture enters the inside of the first casing 26 from the air window 52, the moisture is preferably discharged to the outside through the drain hole 58 after falling down, It is possible to prevent moisture from accumulating in the lower portion of the first casing 26 and adhering to the seal member 32 provided between the convex portion 28 of the first casing 26 and the guide member 18.

  The second casing 38 is formed in a curved concave shape that is open like the first casing 26, and is disposed so that its inner wall surface faces the first casing 26. And, by caulking flange portions 54a and 54b respectively formed on the outermost diameter portion of the first casing 26 and the outermost diameter portion of the second casing 38, the first casing 26 and the second casing 38 Are connected together. At this time, as shown in FIG. 3, since the positioning jigs 56 are inserted into the air windows 52 of the first casing 26, the displacement along the axial direction and the circumferential direction of the first casing 26 is reduced. The second casing 38 is caulked by rolling caulking, for example, with a caulking jig (not shown) with respect to the first casing 26 that is regulated and securely fixed in this manner.

  In addition, a peripheral edge 62 of a diaphragm 60 (to be described later) of the drive mechanism 42 is sandwiched between the flange portions 54 a and 54 b of the first and second casings 26 and 38 and is integrally crimped. Therefore, the peripheral edge 62 of the diaphragm 60 is held by the first and second casings 26 and 38.

  The pilot port 40 is made of a tubular tube material and is press-fitted into the hole of the second casing 38. A pipe connected to a pressure fluid supply source (for example, a vacuum pump) (not shown) is connected to the pilot port 40, and pressure fluid (for example, negative pressure fluid) from the pressure fluid supply source is connected to the pilot port 40. Through the second casing 38.

  The drive mechanism 42 is sandwiched between the first casing 26 and the second casing 38, and is connected to the valve shaft portion 24 of the valve body 16, and a set of first and first sets that hold the diaphragm 60. It consists of second diaphragm plates 64 and 66 and a spring 68 interposed between the second diaphragm plate 66 and the second casing 38.

  The diaphragm 60 is formed from a flexible elastic material (for example, rubber) into a thin disk shape, and its peripheral edge portion 62 is integrally added to the flange portions 54a and 54b of the first and second casings 26 and 38. The substantially central portion is inserted into the end portion of the valve shaft portion 24 in the valve body 16 through the insertion hole 70. As a result, a diaphragm chamber 72 surrounded by the second casing 38 and the diaphragm 60 is formed, and the inside of the diaphragm chamber 72 is kept airtight.

  A first diaphragm plate 64 made of a thin and disk-shaped metal material is disposed on the first casing 26 side of the diaphragm 60, and a substantially central portion of the first diaphragm plate 64 is provided with a hole. The valve shaft portion 24 is inserted. And the 1st diaphragm plate 64 is latched by the latching | locking part 74 which was formed in the valve shaft part 24 and was diameter-expanded radially outward. Thereby, the displacement of the first diaphragm plate 64 toward the valve base 12 is restricted by the locking portion 74.

  On the other hand, on the second casing 38 side of the diaphragm 60, a second diaphragm plate 66 having a substantially U-shaped cross section is disposed from a thin metal material, and is formed at a substantially central portion of the second diaphragm plate 66. The valve shaft portion 24 is inserted through the hole portion. Then, the diaphragm 60 is sandwiched between the first diaphragm plate 64 and the second diaphragm plate 66, and the valve shaft portion 24 is crimped via the washer 76, whereby the diaphragm 60, the first diaphragm plate 64, and the second diaphragm plate are clamped. A diaphragm plate 66 is sandwiched between the crimped portion of the valve shaft portion 24 and the locking portion 74. As a result, the diaphragm 60, the first diaphragm plate 64 and the second diaphragm plate 66 are integrally connected via the valve shaft portion 24.

  The second diaphragm plate 66 is formed with an annular first spring guide 78 that protrudes by a predetermined height toward the second casing 38 (in the direction of arrow A), and is formed on the inner wall surface of the second casing 38. A second spring guide 80 protruding toward the second diaphragm plate 66 (in the direction of arrow B) is formed at a position facing the first spring guide 78. A spring 68 is interposed between the first and second spring guides 78, 80, and the elastic force of the spring 68 causes the second diaphragm plate 66 to move away from the second casing 38 (arrow B direction). ).

  The valve body 16 is made of a metal material, and is disposed in a valve chamber (not shown) of the valve base 12. The valve body 16 is supported by a guide member 18. A valve portion (not shown) is formed at the lower end portion and can be seated on a valve seat (not shown). Further, the end portion of the valve shaft portion 24 is formed in a thin shaft shape that is reduced in the radial inward direction, and the diaphragm 60 and the first and second diaphragm plates 64 and 66 are respectively inserted therethrough.

  The exhaust gas recirculation valve 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described. A valve closed state in which the valve portion (not shown) of the valve body 16 shown in FIG. 1 is seated on the valve seat and the communication state between an inlet port and an outlet port (not shown) is blocked will be described as an initial position.

  In such a valve closed state, negative pressure fluid is supplied from a vacuum pump, which is a pressure fluid supply source (not shown), to the pilot port 40 of the drive unit 14 through a pipe. By introducing this negative pressure fluid into the diaphragm chamber 72 inside the second casing 38, the diaphragm 60 is bent under the negative pressure action of the negative pressure fluid and resists the elastic force of the spring 68. 2. It is sucked and displaced toward the casing 38 side (arrow A direction). Therefore, the first and second diaphragm plates 64 and 66 are displaced in accordance with the displacement of the diaphragm 60, and the valve body 16 connected to the diaphragm 60 is axially guided by the guide hole 22 of the guide member 18 in the axial direction. Along the top (in the direction of arrow A).

  As a result, the valve portion of the valve body 16 is separated from the valve seat, and the valve is in an open state in which the inlet port and the outlet port communicate with each other. As a result, the exhaust gas flowing from the inlet port is discharged from the outlet port through the valve chamber. At this time, the temperature inside the drive unit 14 connected to the valve base 12 may increase due to the exhaust gas flowing through the valve base 12.

  Even in such a case, since the plurality of air windows 52 are formed on the side surface of the first casing 26 in the drive unit 14, the internal heat is released to the outside through the air windows 52, and the outside air Is introduced into the first casing 26 from the air window 52, the inside of the driving unit 14 is suitably cooled, and the temperature can be lowered.

  Next, by stopping the supply of the negative pressure fluid supplied to the drive unit 14, the diaphragm 60 and the first and second diaphragm plates 64 and 66 are pressed toward the valve base 12 side by the elastic force of the spring 68. Then, as the diaphragm 60 is displaced downward, the valve body 16 is integrally displaced downward under the guide action of the guide member 18. At that time, the air in the first casing 26 is discharged to the outside through the air window 52.

  As a result, the valve body 16 is seated on a valve seat (not shown), and the valve body is in a closed state in which the communication state between the inlet port and the outlet port is blocked.

  Next, an exhaust gas cooling bypass valve 150 is illustrated as an exhaust gas valve according to the second embodiment and will be described below with reference to FIG. The same components as those in the exhaust gas recirculation valve 10 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, an exhaust gas cooling bypass valve 150 according to the second embodiment is configured so that exhaust gas exhausted from the exhaust system Ex of the internal combustion engine is exhaust gas recirculation valve provided downstream. 10 through the bypass passage 152, or through the cooling passage 154 to the cooling unit 156 side.

  The exhaust gas cooling bypass valve 150 is provided with a first outlet port (not shown) through which exhaust gas is introduced into the valve base 158, and a second outlet port (not shown) that communicates with the valve chamber below the valve base 158. A connecting portion 160 having a not-shown connection, a first valve portion 164 that blocks communication between the first outlet port and the inlet port 162, and a communication between the second outlet port and the inlet port 162. The exhaust gas recirculation valve 10 according to the first embodiment is that a valve body 166 provided with a second valve portion (not shown) that shuts off the exhaust gas is provided inside the valve base portion 158 so as to be displaceable. Is different.

  An inlet port 162 connected to the exhaust system Ex (see FIG. 4) of the internal combustion engine is formed on the side of the valve base 158, and a valve communicating with the inlet port 162 is formed inside the valve base 158. A chamber (not shown) is formed. The valve chamber is provided with a first valve seat (not shown) that communicates with a first outlet port connected to the bypass passage 152 (see FIG. 4). A second valve seat 168 communicating with the second outlet port connected to the cooling passage 154 (see FIG. 4) is provided on the connection portion 160 side in the valve chamber.

  A driving unit 170 including a diaphragm 60 is connected to the upper portion of the valve base 158 via a bolt 48, and the diaphragm 60 is displaced by a negative pressure fluid supplied to the driving unit 170. The connected valve body 166 is displaced along the axial direction under the guide action of the guide member 18.

  A plurality of air windows 174 are formed on the side surface of the first casing 172 of the driving unit 170, and the inside and the outside of the first casing 172 communicate with each other through the air window 174.

  The air window 174 is provided with positioning jigs 56 (see FIG. 3) when caulking the flange portion 54a of the first casing 172 and the flange portion 54b of the second casing 38 (for example, rolling caulking). The displacement of the first casing 172 can be regulated in the axial direction and the circumferential direction through the positioning jig 56.

  On the other hand, a plurality of (for example, four) drain holes 176 are formed in the lower portion of the first casing 172 so as to straddle the lower surface and side surfaces of the first casing 172. The drain hole 176 is formed at a predetermined interval along the circumferential direction of the first casing 172, and the inside and the outside of the first casing 172 communicate with each other through the drain hole 176.

  That is, in the exhaust gas cooling bypass valve 150, the exhaust gas introduced from the inlet port 162 into the valve chamber is circulated to the first outlet port or the second outlet port by displacing the valve body 166 along the axial direction. It is switched as follows.

  In the exhaust gas cooling bypass valve 150 configured as described above, the inside and the outside of the first casing 172 can be communicated with each other via the air window 174 having a substantially rectangular cross section. Even when the temperature inside the chamber rises due to the influence of the exhaust gas flowing through the valve base 158, heat can be radiated through the air window 174, and the temperature inside the first casing 172 is cooled to lower the temperature. Is possible.

  Further, since the air window 174 is provided on the upper side near the second casing 38 on the side of the first casing 172, when the vehicle on which the exhaust gas recirculation valve 10 is mounted travels. It is possible to suppress muddy water, dust, and the like from entering through the air window 174 from below. Specifically, since the air window 174 is formed on the upper side (arrow A direction) from the substantially central portion along the axial direction (arrow A, B direction) of the first casing 172, the first casing 172. It is possible to prevent moisture, dust, and the like from adhering to the seal member 32 provided above the convex portion 28 and provided inside the convex portion 28.

  Furthermore, by providing a drain hole 176 in the lower portion of the first casing 172, for example, even when moisture enters the inside of the first casing 172 from the air window 174, the moisture falls downward and the drain hole 176 Therefore, the water is accumulated in the lower portion of the first casing 172 and adheres to the seal member 32 provided between the convex portion 28 of the first casing 172 and the guide member 18. Can be prevented.

  In the exhaust gas recirculation valve 10 according to the first embodiment and the exhaust gas cooling bypass valve 150 according to the second embodiment described above, the valve bodies 16 and 166 are axially connected to each other via the diaphragm 60 due to negative pressure. Exhaust gas valves of a negative pressure drive system that is displaced along the direction have been described, but the present invention is not limited to this, and for example, by having a solenoid part including a coil and supplying a current to the solenoid part Air windows 52 and 174 and drain holes 58 and 176 may be provided in an electromagnetically driven exhaust gas recirculation valve that displaces the valve body under the exciting action that occurs.

1 is a partially sectional side view showing an exhaust gas valve according to a first embodiment of the present invention. It is a single-piece | unit perspective view of the 1st casing in the drive part of FIG. FIG. 2 is a partially omitted cross-sectional view showing a state where a positioning jig is inserted into an air window of a first casing in FIG. 1. It is a schematic block diagram of an exhaust gas recirculation system in an internal combustion engine to which an exhaust gas valve is applied. It is a partial cross section side view which shows the valve | bulb for exhaust gas which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Exhaust gas recirculation valve 12, 158 ... Valve base part 14, 170 ... Drive part 16, 166 ... Valve body 18 ... Guide member 26, 172 ... First casing 32 ... Seal member 38 ... Second casing 40 ... Pilot port 42 ... driving mechanism 52, 174 ... air window 56 ... positioning jig 58, 176 ... drain hole 60 ... diaphragm 68 ... spring 150 ... exhaust gas cooling bypass valve 152 ... bypass passage 154 ... cooling passage 156 ... cooling section 160 ... connecting section

Claims (3)

A valve base having a circulation passage for exhaust gas and a valve seat provided in the circulation passage;
A valve body that opens and closes the circulation passage by being seated and separated from the valve seat;
A guide member that is provided inside the valve base and holds the valve body in an axially displaceable manner;
A drive unit having a casing connected to the valve base, and displacing the valve body along an axial direction;
An opening hole formed on a side surface of the casing so as to be in a direction away from the valve base portion along the axial direction with respect to the guide member, and communicating the inside and the outside of the casing;
An exhaust gas valve characterized by comprising: The exhaust gas valve according to claim 1,
The exhaust gas valve according to claim 1, wherein a drain hole is formed in an end of the casing connected to the valve base. The exhaust gas valve according to claim 1,
When the first body connected to the valve base in the casing and the second body disposed in the upper portion along the axial direction of the first body are caulked in the opening hole, the casing An exhaust gas valve, wherein a positioning jig for restricting the displacement of the exhaust gas is inserted.

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