Pressure limiting valve plunger and pressure limiting valve

Abstract

The pressure-limiting valve comprises the plunger, a spring and a plug which are arranged in a valve cavity, the valve cavity is formed in a pump body of an oil pump, an oil inlet communicated with a high-pressure cavity of the oil pump and an oil drainage port communicated with a low-pressure cavity of the oil pump are formed in the side wall of the valve cavity, and the plug is arranged in the valve cavity. The plunger comprises a disc part, a rod-shaped part and a cylinder part which are sequentially connected, a pressure control cavity is formed between the disc part and the inner wall of the valve cavity, the pressure control cavity is communicated with the main oil duct through a feedback oil duct, a stepped through hole penetrating through the rod-shaped part is formed between the disc part and the cylinder part, and the stepped through hole comprises a damping hole and a large through hole; the damping hole is positioned at one end of the disc part; the section, used for installing the spring, of the valve cavity is a spring cavity, and the spring cavity is communicated with the atmosphere through an exhaust hole. After the stepped through hole is formed in the plunger, the fluctuation value of feedback pressure oil can be reduced, and therefore the purpose of reducing pressure fluctuation of an engine is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure limiting valves, and particularly relates to a pressure limiting valve plunger and a pressure limiting valve. Background Art

[0002] With the development of pump design technology, the structure of opening the pressure limiting valve by the feedback pressure of the main oil passage has been popularized, because this structure can more accurately control the opening pressure of the oil pump pressure limiting valve. However, the oil passage length of the feedback oil passage in this structure will be relatively lengthened. As the feedback oil passage is lengthened, the response time of the pressure limiting valve will also be lengthened, resulting in that the pressure of the main oil passage has changed before the pressure regulating requirement of the previous stage is fully executed by the pressure limiting valve, thus causing matching pressure fluctuations.

[0003] A common solution is to add a throttle hole in the feedback oil passage to play a damping role, reduce the flow rate of the oil pump in the feedback oil passage, and reduce the moving speed of the pressure limiting valve to reduce the pressure fluctuation of the main oil passage. However, the throttle hole structure cannot completely solve the problem in some engine models. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a pressure limiting valve plunger and a pressure limiting valve that can reduce pressure fluctuations.

[0005] The technical solution of the utility model regarding the pressure limiting valve plunger is: a pressure limiting valve plunger, which comprises a disc part, a rod-shaped part, and a cylindrical part connected in sequence. A stepped through-hole penetrating the rod-shaped part is provided between the disc part and the cylindrical part. The stepped through-hole includes a damping hole and a large through-hole, and the damping hole is located at the end of the disc part.

[0006] Further, a groove is provided on the end face of the disc part.

[0007] The technical solution of the utility model regarding the pressure limiting valve is: a pressure limiting valve, which comprises a plunger, a spring, and a plug arranged in a valve cavity. The valve cavity is opened on the pump body of the oil pump. An oil inlet communicating with the high-pressure cavity of the oil pump and an oil drain port communicating with the low-pressure cavity of the oil pump are opened on the side wall of the valve cavity. The plunger includes a disc part, a rod-shaped part, and a cylindrical part connected in sequence. A pressure control cavity is formed between the disc part and the inner wall of the valve cavity. The pressure control cavity is communicated with the main oil passage through a feedback oil passage. A stepped through-hole penetrating the rod-shaped part is provided between the disc part and the cylindrical part. The stepped through-hole includes a damping hole and a large through-hole, and the damping hole is located at the end of the disc part. The section of the valve cavity for installing the spring is a spring cavity, and the spring cavity is communicated with the atmosphere through an exhaust hole.

[0008] Further, a groove is provided on the end face of the disc part.

[0009] In one embodiment, the exhaust hole is arranged on the plug.

[0010] Since the pressure control chamber of the pressure limiting valve is filled with feedback pressure oil from the main oil passage, affected by the pressure fluctuation of the main oil passage, there will also be a certain fluctuation in the feedback pressure oil, which will push the plunger of the pressure limiting valve to oscillate back and forth, affecting the normal adjustment of the pressure limiting valve. After the stepped through-hole is arranged on the plunger in the utility model, a small part of the feedback pressure oil will be discharged through the damping hole. This small part of the feedback pressure oil enters the spring chamber through the large through-hole and then is discharged outward through the exhaust hole. While a small part of the feedback pressure oil is discharged, the peak value of the fluctuation of the feedback pressure oil is absorbed, and the fluctuation value of the feedback pressure oil is reduced, so as to achieve the purpose of reducing the pressure fluctuation of the engine. Description of the Drawings

[0011] Figure 1 It is a schematic structural diagram of the plunger of the pressure limiting valve in the embodiment of the utility model;

[0012] Figure 2 It is a schematic structural diagram of the pressure limiting valve in the embodiment of the utility model;

[0013] The reference numerals are:

[0014] 10. Plunger; 11. Disc part; 12. Rod-shaped part; 13. Cylindrical part; 14. Damping hole; 15. Large through-hole; 20. Spring; 30. Plug; 40. Pump body; 50. Oil inlet; 60. Oil drain port; 70. Pressure control chamber; 80. Feedback oil passage; 90. Exhaust hole. Detailed Embodiment

[0015] For the convenience of understanding by those skilled in the art, the present utility model will be further described below in conjunction with the embodiments and the drawings. The content mentioned in the embodiments does not limit the present utility model.

[0016] It should be noted in advance that in the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations. Embodiment 1

[0017] As Figure 1 shown, a plunger of a pressure limiting valve includes a disc part 11, a rod-shaped part 12, and a cylindrical part 13 that are connected in sequence. A stepped through-hole penetrating the rod-shaped part 12 is provided between the disc part 11 and the cylindrical part 13. The stepped through-hole includes a damping hole 14 and a large through-hole 15. The damping hole 14 is located at the end of the disc part 11, and a groove is provided on the end face of the disc part 11. Embodiment 2

[0018] AsFigure 1 , 2 As shown in 2 , a pressure limiting valve includes a plunger 10, a spring 20, and a plug 30 disposed in a valve cavity. The valve cavity is formed on a pump body 40 of an oil pump. An oil inlet 50 communicating with a high-pressure chamber of the oil pump and an oil drain port 60 communicating with a low-pressure chamber of the oil pump are formed on a side wall of the valve cavity. The plunger 10 includes a disc portion 11, a rod-shaped portion 12, and a cylindrical portion 13 that are sequentially connected. A groove is provided on an end face of the disc portion 11. A pressure control chamber 70 is formed between the disc portion 11 and an inner wall of the valve cavity. The pressure control chamber 70 communicates with a main oil passage through a feedback oil passage 80. A stepped through hole penetrating the rod-shaped portion 12 is provided between the disc portion 11 and the cylindrical portion 13. The stepped through hole includes a damping hole 14 and a large through hole 15. The damping hole 14 is located at this end of the disc portion 11. A section of the valve cavity for installing the spring 20 is a spring cavity. The spring cavity communicates with the atmosphere through an exhaust hole 90. The exhaust hole 90 is provided on the plug 30.

[0019] Since the pressure control chamber 70 of the pressure limiting valve is filled with feedback pressure oil from the main oil passage, affected by the pressure fluctuation of the main oil passage, the feedback pressure oil will also have a certain fluctuation, thereby pushing the plunger 10 of the pressure limiting valve to oscillate back and forth, affecting the normal adjustment of the pressure limiting valve. In this embodiment, after the stepped through hole is provided on the plunger 10, a small part of the feedback pressure oil will be discharged through the damping hole 14. This small part of the feedback pressure oil enters the spring 20 cavity through the large through hole 15, and then is discharged to the outside through the exhaust hole 90. While a small part of the feedback pressure oil is discharged, the fluctuation peak value of the feedback pressure oil is also absorbed, and the fluctuation value of the feedback pressure oil is reduced, thereby achieving the purpose of reducing the engine pressure fluctuation.

[0020] In order to enable those of ordinary skill in the art to more conveniently understand the improvements of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified. In addition, the above embodiments are preferred implementation solutions of the present invention. Besides, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the technical solution is within the protection scope of the present invention.

Claims

1. A pressure-limiting valve plunger, comprising a disc portion (11), a rod-shaped portion (12), and a cylindrical portion (13) that are connected in sequence, characterized in that: A stepped through-hole penetrating the rod-shaped portion (12) is provided between the disc portion (11) and the cylindrical portion (13), and the stepped through-hole includes a damping hole (14) and a large through-hole (15), and the damping hole (14) is located at this end of the disc portion (11).

2. The pressure-limiting valve plunger according to claim 1, wherein: A groove is provided on the end face of the disc portion (11).

3. A pressure limiting valve, comprising a plunger (10), a spring (20) and a plug (30) disposed in a valve cavity, wherein the valve cavity is formed on a pump body (40) of an oil pump, an oil inlet (50) communicating with a high-pressure chamber of the oil pump and an oil drain port (60) communicating with a low-pressure chamber of the oil pump are formed on a side wall of the valve cavity, the plunger (10) includes a disc portion (11), a rod-shaped portion (12) and a cylindrical portion (13) which are connected in sequence, a pressure control cavity (70) is formed between the disc portion (11) and an inner wall of the valve cavity, and the pressure control cavity (70) is communicated with a main oil passage through a feedback oil passage (80), and is characterized in that: A stepped through-hole penetrating the rod-shaped portion (12) is provided between the disc portion (11) and the cylindrical portion (13), and the stepped through-hole includes a damping hole (14) and a large through-hole (15), and the damping hole (14) is located at this end of the disc portion (11); a section of the valve cavity for installing the spring (20) is a spring (20) cavity, and the spring (20) cavity communicates with the atmosphere through an exhaust hole (90).

4. The pressure limiting valve according to claim 3, wherein: A groove is provided on the end face of the disc portion (11).

5. The pressure-limiting valve according to claim 3 or 4, characterized in that: The exhaust hole (90) is provided on the plug (30).

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