A structure for reducing valve gas flow leakage in EGR valve

Abstract

A structure for reducing valve gas flow leakage in an EGR valve comprises a valve seat, a valve stem arranged in the valve seat, an air inlet and an air outlet arranged on the valve seat, a bushing arranged in the valve seat, a diaphragm for sealing the air inlet and the air outlet arranged above the bushing, the outer diameter of the diaphragm being larger than the inner diameter of the bushing, the diaphragm being inserted into a boss at the end of the valve stem, and the boss being riveted to the diaphragm through a riveting structure. The present invention solves the problem that the traditional EGR valve structure has a valve stem and a bushing that are offset due to different road conditions, vibrations, bumps and other factors, and the EGR valve has valve gas leakage caused by the offset of the valve stem and the bushing, thereby affecting the driving of the car, and the traditional structure has a low production qualification rate, high parts processing precision and high cost.

Description

Technical Field

[0001] The invention relates to the technical field of automobile engines, and in particular to a structure for reducing valve gas flow leakage in an EGR valve. Background Art

[0002] The traditional EGR valve for automobiles drives the movement of the valve stem by evacuating the vacuum chamber to control the opening degree of the valve, thereby controlling the exhaust gas from entering the combustion chamber, reducing the temperature and pressure of the combustion chamber, and reducing the amount of nitrogen oxides generated. The EGR valve does not work when the engine is idling, running at low speed and low load, and when the engine is in cold state, and when the engine power is required at full load, so the valve stem and the bushing need to be sealed at this time, and the leakage is allowed to be ≤5SLPM / min. However, the traditional EGR valve stem and the vacuum chamber motion component are riveted together, which is prone to offset. In addition, due to different road conditions during the driving of the car, there are factors such as vibration and bumps that cause the compression spring to offset. The EGR valve will have a valve stem and bushing offset, causing leakage, thereby affecting the driving of the car. In addition, the traditional structure has a low production qualification rate, high parts processing precision, and high cost. Therefore, it is necessary to invent a structure that can reduce the leakage of valve gas flow in the EGR valve without EGR valve leakage under different driving conditions, while reducing production costs. Summary of the invention

[0003] The purpose of the present invention is to provide a structure for reducing the valve gas flow leakage in the EGR valve, so as to solve the problem that the traditional EGR valve structure may cause the compression spring to shift due to different road conditions, vibration, bumps and other factors when the car is driving, and the EGR valve may have a valve stem and a bushing shift resulting in leakage, thereby affecting the driving of the car, and the traditional structure has a low production qualification rate, high parts processing precision and high cost.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A structure for reducing valve air flow leakage in an EGR valve comprises a valve seat, a valve stem arranged in the valve seat, the valve seat is provided with an air inlet and an air outlet, a bushing is arranged in the valve seat, a diaphragm for sealing the air inlet and the air outlet is arranged above the bushing, the outer diameter of the diaphragm is larger than the inner diameter of the bushing, the diaphragm is inserted into a boss at the end of the valve stem and is loosely fitted, and the boss is riveted to the diaphragm through a riveting structure.

[0006] Furthermore, in order to ensure that the diaphragm can still be sealed intactly with the bushing after the valve stem is riveted and tilted, a conical surface structure is provided on the valve stem at a position relative to the upper end surface of the diaphragm.

[0007] Furthermore, in order to limit the deviation of the valve stem, the angle of the conical surface structure is 160 degrees.

[0008] Furthermore, in order to ensure that the valve stem and the diaphragm can still move up and down after the valve stem is riveted and tilted, a movable gap is provided between the flip riveting structure and the diaphragm.

[0009] Furthermore, in order to limit the range of movement between the valve stem and the diaphragm, the movement gap is 0.3-0.5 mm.

[0010] Furthermore, in order to prevent corrosion, the material of the diaphragm is stainless steel.

[0011] Beneficial effects of the present invention: The structure of the present invention changes the traditional EGR valve stem and bushing into a valve stem and two flat stamping parts of a diaphragm and a bushing, and a conical surface structure is provided on the valve stem relative to the upper end surface of the diaphragm, wherein the diaphragm and the valve stem can move up and down after riveting, and a seal is achieved by cooperating with the movable valve stem assembly and the bushing flat part, thereby reducing valve flow leakage, while having low production costs and high product qualification rate.

[0012] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a cross-sectional view of a structure for reducing valve gas flow leakage in an EGR valve.

[0014] Figure 2 It is a schematic diagram of the matching structure of the valve stem and the diaphragm in the present invention.

[0015] Figure 3 It is a schematic diagram of the cooperation between the valve stem and the diaphragm when the valve stem is skewed and offset in the present invention. DETAILED DESCRIPTION

[0016] like Figure 1 and Figure 2 A structure for reducing valve air flow leakage in an EGR valve is shown, comprising a valve seat 1, a valve stem 2 arranged in the valve seat 1, the valve seat 1 being provided with an air inlet 11 and an air outlet 12, a bushing 3 being arranged in the valve seat 1, a diaphragm 4 for sealing the air inlet 11 and the air outlet 12 being arranged above the bushing 3, the outer diameter of the diaphragm 4 being larger than the inner diameter of the bushing 3, the diaphragm 4 being inserted into the boss at the end of the valve stem 2 and being loosely fitted, a recessed hole for riveting may be arranged on the boss at the end of the valve stem, the boss being connected to the diaphragm 4 by riveting to form a riveted structure 21.

[0017] In order to ensure that the diaphragm 4 can still be well sealed with the bushing 3 after the valve stem 2 is riveted and tilted, a conical structure 22 is provided on the valve stem 2 at a position relative to the upper end surface of the diaphragm 4 .

[0018] In order to limit the deflection of the valve stem 2, the angle of the conical structure 22 is 160 degrees.

[0019] In order to ensure that the valve stem 2 and the diaphragm 4 can still move up and down after the valve stem 2 is riveted and tilted, a movable gap 23 is provided between the flip riveting structure 21 and the diaphragm 4 .

[0020] In order to limit the range of movement between the valve stem and the diaphragm, the movement gap 23 is 0.3-0.5 mm.

[0021] In order to prevent corrosion, the material of the diaphragm 4 can be stainless steel.

[0022] like Figure 3 As shown, when the valve stem 2 is riveted and skewed, the diaphragm 2 can still be sealed with the bushing 3 intactly due to the movable gap 23 between the valve stem 2 and the diaphragm 4; a conical structure 22 is provided on the valve stem 2 at a position relative to the upper end surface of the diaphragm 4, and the valve stem 2 presses the diaphragm 4 in a stationary state to play a sealing role. When the valve stem 2 is not aligned with the bushing 4 after riveting, the diaphragm 4 can still completely cover the pores of the bushing 3 for sealing due to the large coverage area between the bushing 3 and the diaphragm 4. Therefore, regardless of the vibration and bumps during the driving of the car, the skewed offset of the valve stem 2 after riveting, or the eccentricity of the valve stem 2 with the bushing 4 after riveting, the EGR valve will not have a large amount of valve flow leakage.

[0023] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or they are directly applied to other occasions without improvement, they all fall within the protection scope of the present invention.

Claims

1. A structure for reducing valve gas flow leakage in an EGR valve, comprising a valve seat (1), a valve stem (2) arranged in the valve seat (1), the valve seat (1) being provided with an air inlet (11) and an air outlet (12), the valve seat (1) being provided with a bushing (3), characterized in that: A diaphragm (4) for sealing the air inlet (11) and the air outlet (12) is arranged above the bushing (3); the outer diameter of the diaphragm (4) is larger than the inner diameter of the bushing (3); the diaphragm (4) is inserted into the boss at the end of the valve stem (2) and is loosely fitted; the boss is riveted to the diaphragm (4) via a riveting structure (21); a conical structure (22) is arranged on the valve stem (2) at a position relative to the upper end surface of the diaphragm (4); and a movable gap (23) is arranged between the riveting structure (21) and the diaphragm (4).

2. The structure for reducing valve gas flow leakage in an EGR valve according to claim 1, characterized in that: The angle of the conical surface structure (22) is 160 degrees.

3. The structure for reducing valve gas flow leakage in an EGR valve according to claim 1, characterized in that: The movable gap (23) is 0.3-0.5 mm.

4. The structure for reducing valve gas flow leakage in an EGR valve according to claim 1, characterized in that: The material of the diaphragm (4) is stainless steel.

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