JPH0422750A - Negative pressure control valve for internal combustion engine - Google Patents

Abstract

PURPOSE:To surely adjust right and left thrust transferring quantity without a special work on the shaft by suppressing the thrust to one direction of the shaft with a stopper plate holding the shaft fixed thereto, and suppressing the thrust to the other direction with the plug end face attached to a cylindrical part. CONSTITUTION:In a negative pressure control valve 1, a valve 1a is fixed to a shaft 5 with a bearing 5a. A main body 6 has a passage 6a at which flow air passes, and the shaft 5 is maintained thereby. In this case, at the shaft 5, a groove is provided, and a retaining ring 7 is inserted so as to interpose a washer 8 between the main body 6 and the retaining ring 7. At the main body 6, a cylindrical part which surrounds the shaft end is provided, and a plug 9 is fixed thereto. The shaft 5 thereby touches the washer 8 at a main body 6 when it moves to the right direction, and the shaft 5 touches the plug 9 when it moves to the left direction. A rattle l to both the thrust directions of the shaft 5 is suppressed, the atmospheric air and the passage 6a is divided with the plug 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a negative pressure control valve used in an exhaust gas recirculation device for an internal combustion engine.

[Conventional technology]

In the intake throttle device for a diesel engine known from Japanese Patent Laid-Open No. 56-167826, etc., a butterfly-type negative pressure control valve is provided in the intake passage, and its opening degree is controlled according to the negative pressure downstream of the valve. The valve is configured to control the mixing ratio of exhaust gas recirculated from the exhaust pipe into the intake pipe downstream of the valve and intake air in accordance with the negative pressure.

This butterfly type negative pressure control valve was published in Japanese Patent Application Laid-Open No. 57-865.
Similar to the valve known in Publication No. 37, it is composed of a shaft that passes through the intake pipe, a butterfly valve fixed to this shaft, and a stopper plate that restricts the amount of movement of this shaft in the thrust direction.

When the shaft moves in the thrust direction, the stopper plate restricts the amount of movement to prevent the peripheral edge of the butterfly valve from contacting or biting the inner wall of the intake pipe.

Since the amount of movement in the thrust direction needs to be regulated in both left and right directions, the valve mechanism disclosed in JP-A-57-86537 provides a groove at the shaft end and changes the thickness of the stopper plate that fits into this groove. , the left and right thrust regulation amount can be adjusted.

[Problem to be solved by the invention]

In such conventional examples, the hard shaft had to be machined into a special shape, and in order to accurately adjust the thrust restriction amount, it was necessary to machine the shaft with high precision.

Furthermore, no consideration was given to the possibility of air leaking from the gap between the shaft and the bearing or dust entering from the outside.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thrust adjustment mechanism that eliminates the above-mentioned conventional drawbacks and can accurately adjust the amount of left and right thrust movement without special machining of the shaft.

Another object of the present invention is to provide a thrust adjustment mechanism that can prevent air leakage and dust intrusion from the gap between the shaft and the bearing without any special sealing means.

[Means to solve the problem]

The above object of the present invention is to fix a stopper plate near the end of the shaft to receive the thrust 1 in the direction in which the shaft retreats, and to provide a cylindrical part in the bearing body that surrounds the shaft end; This is achieved by fitting a plug into the inner periphery of this cylindrical portion and configuring the gap between the end face of the plug and the end face of the shaft to restrict the thrust 1- in the direction in which the shaft projects.

Furthermore, by attaching the plug airtightly to the cylindrical part, it is possible to seal it from the outside air.

[Effect]

According to the present invention configured as described above, the thrust in one direction of the shaft is regulated by the stopper plate 1 fixed to the shaft, and the thrust in the other direction is regulated by the end face of the plug attached to the cylindrical part. Because you can.

Thrust regulation in both directions can be achieved with a simple mechanism.

Furthermore, if the plug is installed airtight, sealing inside and outside the intake pipe can be easily achieved without providing any other special sealing means.

〔Example〕

The invention will be described in detail below based on one embodiment shown in the five drawings. The negative pressure control valve 1 controls the valve 1 according to its downstream negative pressure.
The opening degree of a is controlled, and the mixing ratio of exhaust gas 3 of the engine 2 and intake air 4, which are recirculated into the intake pipe downstream of this valve, is controlled. Its structure is as shown in FIG. 2, in which the valve 1a is fixed to the shaft 5 by a screw 5a.The main body 66 has a passage 6a through which the incoming air 4 passes, and holds the shaft 5. ing. Also, on axis 5,
As shown in FIG. 3, a groove is provided in which a stopper 7 is inserted and installed, and a washer 8 is interposed between the main body 6 and the stopper 7. Further, the main body 6 is provided with a cylindrical portion surrounding the shaft end, and a plug 9 is fixed thereto. Therefore, when the shaft 5 moves to the left in the figure, the washer 8 hits the main body, and when it moves to the right in the figure, the shaft 5 hits the plug 9.
corresponds to Therefore, the backlash 80 of the shaft 5 in both thrust directions is restricted. Therefore, by precisely machining the machining depth Q of the main body 6, the offset ΔQ can be reduced. Furthermore, since the atmosphere and the passage 6a are blocked by the plug 9, there is an effect that there is no need to use an expensive dust seal or the like. The plug is rubber.
Either resin or metal may be used. Note that the washer 8 may be a leaf spring. In addition, the stopper plate is
It may be just that. That is, the stopper 7 may also serve as the washer 8.

〔Effect of the invention〕

As explained above, according to the present invention, by an inexpensive method,
Furthermore, it is possible to provide a negative pressure control valve for an automobile exhaust gas recirculation device that is highly reliable over the long term.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an exhaust gas recirculation (EGR) device for an internal combustion engine applied to the present invention, FIG. 2 is a cross-sectional diagram of the negative pressure control valve of FIG. 1 according to the present invention, and FIG. FIG. 2 is an enlarged schematic diagram of section P in FIG. 2; 1...Negative pressure control valve, 2...Engine, 5...Shaft,
7... Stop diagram Figure 2

Claims (1)

[Claims] 1. A negative pressure control valve for an internal combustion engine that controls a negative pressure value on the downstream side of the valve, characterized in that an end of the valve stem is brought into contact with a member fixed to the main body. Pressure control valve. 2. The negative pressure control valve for an internal combustion engine according to claim 1, wherein the member fixed to the main body is a plug. 3. The negative pressure control valve for an internal combustion engine according to claim 1, characterized in that a stopper plate is installed on the valve shaft. 4. The negative pressure control valve for an internal combustion engine according to claim 2, wherein the plug is made of metal. 5. The negative pressure control valve for an internal combustion engine according to claim 2, wherein the plug is made of rubber. 6. The negative pressure control valve for an internal combustion engine according to claim 2, wherein the plug is made of resin. 7. The negative pressure control valve for an internal combustion engine according to claim 3, wherein the stopper plate is a retaining ring. 8. The negative pressure control valve for an internal combustion engine according to claim 3, characterized in that a washer is fitted and installed between the stopper plate and the main body. 9. The negative pressure control valve for an internal combustion engine according to claim 3, wherein the washer is a leaf spring. 10. In a negative pressure control valve for an internal combustion engine that controls the negative pressure value on the downstream side of the valve, a cylindrical part surrounding the shaft end is provided in the bearing body, and a member is fitted to the inner periphery of this cylindrical part. Characteristic negative pressure control valve for internal combustion engines. 11. The negative pressure control valve for an internal combustion engine according to claim 1, wherein the fitted member is an elastic seal plug.