JPS6244093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve for an exhaust gas recirculation system for an internal combustion engine for an automobile.

FIG. 1 is an explanatory diagram of an exhaust gas recirculation device using a conventional control valve.

Air taken into an intake pipe 1 is mixed with fuel while passing through a bench lily 2 and a throttle valve 3 and burned in the engine, and the exhaust gas is discharged from an exhaust pipe 4. An exhaust gas recirculation passage 5 connects the intake pipe 1 and the exhaust pipe 4 by bypassing the engine, through which part of the exhaust gas is sent back to the engine to suppress the generation of nitrogen oxide components in the exhaust gas. .

The exhaust gas recirculation passage 5 is provided with an exhaust gas recirculation valve 6 for adjusting the amount of exhaust gas passing therethrough, and the exhaust gas recirculation valve 6 is controlled by a control valve 7, which is the object of the present invention.

An exhaust inlet chamber 8 serving as an exhaust inlet of the exhaust recirculation valve 6 communicates with the exhaust pipe 4 via an orifice 9.
A diaphragm 11 to which a needle valve 10 is attached, which forms a measuring part of an exhaust gas recirculation valve 6 that regulates the amount of exhaust gas recirculation, is located between an atmospheric pressure chamber 12 and a negative pressure working chamber 13, and the negative pressure working chamber 13 is located above a predetermined level. When the negative pressure is reached, the diaphragm 11 rises to a point where it balances the biasing force of the compression spring 14, and the needle valve 1
Open 0.

Negative pressure near the throttle valve 3 is introduced into the negative pressure working chamber 13 via a control negative pressure passage 15 . The negative pressure within the negative pressure working chamber 13 is controlled by a control valve 7 described below.

A large diameter diaphragm 17 is disposed at one end of the hollow body 16, and a negative pressure chamber 19 is formed by a case 18 fixed to the body 16.

Further, a small-diameter diaphragm 20 is disposed at the other end of the body 16, and a discharge pressure chamber 22 is formed by a case 21 fixed to the body 16. A control pressure chamber 23 is formed by the diaphragms 17, 20 and the body 16. Therefore, in the control valve 7, the negative pressure chamber 19, the control pressure chamber 23, and the exhaust pressure chamber 22 are arranged in this order. The negative pressure chamber 19 has a bench lily negative pressure nipple (hereinafter referred to as Vc
A nipple (referred to as a nipple) 24 is opened, and the bench lily negative pressure is introduced into the negative pressure chamber 19 through this. The control pressure chamber 23 is communicated with the atmosphere via a filter 25. The pressure of the exhaust gas inlet chamber 8 is introduced into the exhaust pressure chamber 22 via an exhaust pressure nipple 26 . The two diaphragms 17 and 20 are connected by a connecting member 27. A sealing material 28 is provided on the upper surface of the diaphragm 20, that is, on the control pressure chamber 23 side, and an atmosphere opening port 29 is located close to and facing this sealing material 28. This atmosphere opening port 29 communicates with the negative pressure working chamber 13 via a control pressure nipple 30, so that the pressure in the negative pressure working chamber 13 can be controlled. A compression spring 31 is disposed in the control pressure chamber 23 and urges the connecting member 27 to separate the sealing material 28 from the atmosphere opening 29.

Here, the control pressure nipple 30 is fixed to the case 18 so as to coincide with the axis of the control valve 7. That is, the diaphragm 17 is configured as an annular diaphragm, the outer peripheral edge of the annular diaphragm 17 is held between the case 18 and the body 16, and the inner peripheral edge is located in the case 18 and the control pressure chamber 23 and fixed to the case 18. It is held between holding members 32. A control pressure nipple 30 that passes through the holding member 32 and has an atmosphere opening 29 that closely faces the sealing material 28 is attached to the threaded portion 33 of the holding member 32.
It is fixed with screws. This holding member 32 has a flange 34, and the inner peripheral edge of the diaphragm 17 is held between the flange 34 and the case 18. By screwing the control pressure nipple 30 having the atmosphere opening 29 into the threaded portion 34, the case 18 and the control pressure nipple 30 are integrated. In addition, Vc nipple 24 is case 1
8 and is formed integrally with the case 18. here,
The body 16, case 18, and case 21 are all made of synthetic resin.

The operation of the conventional exhaust gas recirculation device configured as described above will be explained with reference to FIG.

A negative pressure signal from the vent lily 2, which is proportional to the intake air amount of the engine, is led to the negative pressure chamber 19 of the control valve 7 via the Vc nipple 24, causing the diaphragm 17 to rise. That is, during high-speed rotation with a large amount of intake air, the negative pressure signal of the bench lily 2 increases, so that the diaphragm 17 overcomes the biasing force of the compression spring 31.
rises, and the sealing member 28 approaches the atmosphere opening 29. When this gap narrows, the negative pressure leaked to the atmosphere from the atmosphere opening 29 via the control pressure chamber 23 and the filter 25 decreases, so the exhaust recirculation valve 6 The negative pressure signal led to the negative pressure working chamber 13 increases.
As a result, the needle 10 attached to the diaphragm 11 of the exhaust gas recirculation valve 6 rises, increasing the amount of exhaust gas recirculation. Further, the pressure of the exhaust inflow chamber 8 is applied to the exhaust pressure chamber 22 of the control valve 7 via the exhaust pressure nipple 26,
A force acts to raise the diaphragm 20, but once the exhaust gas begins to recirculate, the pressure decreases and the exhaust gas recirculation valve 6
When the ventilation area of the needle 10 becomes larger than the ventilation area of the orifice 9, the exhaust gas inflow chamber 8 becomes a negative pressure due to the negative pressure of the intake pipe 1, and as a result, the rise of the diaphragm 20 is suppressed. Thus,
The negative pressures in the negative pressure chamber 19 and the exhaust pressure chamber 22 of the control valve 7 are balanced in an inverse ratio of the effective areas of the diaphragms 17 and 20, and the gap between the sealing member 28 and the atmosphere opening 29 is closed at the balanced position. It will be controlled.

As a result, an exhaust gas recirculation amount proportional to the amount of intake air can be obtained.

By the way, the negative pressure chamber 19 constituting the control valve 7
The inner peripheral edge of the diaphragm 17 that separates the control pressure chamber 23 from the case 18 and the flange 34 of the holding member 32
This clamping method is performed using the holding member 32.
This is done by screwing the control pressure nipple 30 into the threaded portion 34 of the.

However, in this case, since the holding member 32, the control pressure nipple 30, and the case 18 are each separate members, ease of assembly is not good. In addition, these are made of synthetic resin, and include a holding member 32 and a control pressure nipple 3.
If 0 is connected with a screw, there is a problem that the threaded portion may become loose or break due to the low creep strength of the material.

An object of the present invention is to provide a control valve that is easy to assemble and has a strong connection between the control pressure nipple and the holding member.

A feature of the present invention is that the control pressure nipple and the holding member are integrally formed, and the inner circumferential surface of the diaphragm is held between the side circumferential surface of the flange of the holding member and the case.

The present invention will be explained below based on FIGS. 2 and 3. In FIG. 2, the holding member 32 and the control pressure nipple 30 are integrally formed and welded to the case 18. The inner peripheral edge of the diaphragm 17 is held between the side peripheral surface 34A of the flange 34 extending into the control pressure chamber 23 and the case 18. Therefore, the negative pressure chamber 19 and the control pressure chamber 23 are airtightly partitioned by the diaphragm 17.

Here, since the control pressure nipple 30 and the holding member 32 are integrally formed, ease of assembly is improved, and since the control pressure nipple 30 and the holding member 32 are not connected by screw connection, loosening and damage due to creep occur. can be eliminated.

FIG. 3 shows another embodiment, in which the holding member 3
A spring receiver 35 is slidably disposed within the flange 34 of No. 2, and the spring 31 is in contact with the spring receiver 35. And the spring receiver 35 has a protrusion 36
is inserted through the holding member 32 and protrudes to the outside.
This protrusion 36 is in contact with a leaf spring 37 inserted through the control pressure nipple 30, and the leaf spring 37 is changed in position by an adjusting nut 38 screwed into a threaded portion formed in the control pressure nipple 30. Accordingly, the load of the spring 31 is adjusted.

Therefore, the timing at which the sealing material 28 opens and closes the atmosphere opening 29 can be adjusted.

As described above, in the present invention, the control pressure nipple and the holding member are integrally formed, and the inner circumferential edge of the diaphragm is sandwiched between the side circumferential surface of the holding member and the case, which facilitates assembly and improves controllability. A control valve with a strong connection between the pressure nipple and the holding member can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an exhaust gas recirculation device using a conventional control valve, FIG. 2 is a cross-sectional view of an exhaust gas recirculation device using a control valve according to an embodiment of the present invention, and FIG. FIG. 2 is a sectional view of a control valve according to another embodiment of the present invention. 1... Intake pipe, 2... Bench lily, 3... Throttle valve, 4... Exhaust pipe, 5... Exhaust recirculation passage, 6...
Exhaust recirculation valve, 7... Control valve, 8... Exhaust inflow chamber,
9... Orifice, 13... Negative pressure working chamber, 16...
...Body, 17...Diaphragm, 18...Case, 19...Negative pressure chamber, 20...Diaphragm, 2
DESCRIPTION OF SYMBOLS 1... Case, 22... Exhaust pressure chamber, 23... Control pressure chamber, 24... Vc nipple, 26... Exhaust pressure nipple, 27... Connection member, 28... Seal material, 29
...Atmospheric release port, 30...Control pressure nipple, 31
... Spring, 32 ... Holding member, 34 ... Flange, 34A ... Side peripheral surface, 35 ... Spring receiver, 36 ... Protrusion, 37 ... Leaf spring, 38 ...
adjustment nut.

Claims (1)

[Claims] 1 The first case held between the body and the first case
diaphragm, the negative pressure in the vent lily portion formed by the first diaphragm and the first case and formed in the intake pipe is introduced through a vent lily negative pressure nipple provided in the first case. a pressure chamber, a second diaphragm held between the body and the second case, a control pressure chamber formed in the body, the first diaphragm, and the second diaphragm and into which atmospheric pressure is introduced; a control pressure nipple communicating with a negative pressure operating chamber to which intake negative pressure of an exhaust gas recirculation valve provided in the middle of the exhaust gas recirculation passage is guided, the second diaphragm and the second diaphragm having an atmosphere opening port opening into the control pressure chamber; The pressure between the exhaust gas recirculation valve formed by the exhaust gas recirculation passage and the orifice located upstream of the exhaust gas recirculation valve is introduced via an exhaust pressure nipple provided in the second case. a connecting member connecting the first diaphragm and the second diaphragm; a sealing member fixed to the second diaphragm and closely facing the atmosphere opening of the control pressure nipple; and the second sealing material is placed in a manner such that the sealing material is kept away from the atmosphere opening port.
In the control valve for an exhaust gas recirculation device comprising a compression spring that biases a diaphragm, the first diaphragm is configured as an annular diaphragm,
The outer peripheral edge of the annular diaphragm is held between the first case and the body, and the inner peripheral edge is held between the first case and the body.
The first case is airtightly sandwiched between the side circumferential surface of the holding member located in the control pressure chamber, and the holding member and the control pressure nipple are integrally formed and fixed to the first case. control valve for the exhaust gas recirculation system.