Pressure regulating valve with exhaust function for diesel pump

Abstract

The utility model relates to a kind of pressure regulating valve with exhaust function for diesel pump, including valve body, sphere, compression spring and valve core, valve cavity is equipped in valve body, sphere and compression spring are installed in valve cavity, valve core is slidably installed in valve cavity, sphere and valve core are respectively located at the both ends of compression spring, oil return hole one is equipped on the lateral wall of valve cavity, oil inlet hole, exhaust oil return hole and oil return hole two are equipped in communication on valve core, oil inlet hole and exhaust oil return hole are set along the axis direction of valve core, oil return hole two is set on the lateral wall of valve core. By setting valve body and valve core, and setting oil inlet hole, exhaust oil return hole and oil return hole two on valve core, so that the pressure regulating valve not only has pressure regulating function, but also can effectively discharge air in low-pressure oil circuit when diesel pump works, prevent air resistance formed due to air accumulation, ensure that fuel can be smoothly delivered to pump head area, to establish rail pressure stably.

Description

Technical Field

[0001] This utility model relates to the field of pressure regulating valve technology, specifically to a pressure regulating valve with venting function for a diesel pump. Background Technology

[0002] Diesel engines use pressurized fuel, so the fuel injected into the combustion chamber needs to have sufficient pressure. Generally, a high-pressure diesel pump supplies fuel to the combustion chamber via injectors. To ensure a continuous and stable fuel supply to the combustion chamber, the fuel pump is always in a high-volume fuel supply mode. During the entire cycle, approximately 90% of the fuel will return to the low-pressure circuit through a bypass, and only about 10% of the fuel will be supplied to the combustion chamber through the injectors.

[0003] In the current design of the low-pressure oil circuit of diesel pumps, the low-pressure oil circuit (see...) Figure 7 and Figure 8 The system (as shown) includes a throttle orifice 21 to control the flow of fuel into the venturi line, thereby creating negative pressure to draw excess fuel back to the fuel tank from the injector. A one-way valve is added after the throttle orifice 21 to allow more fuel to enter the pump head, which is beneficial for establishing rail pressure during low-speed engine startup. Furthermore, by connecting a small vent hole 22 in parallel to the side of the one-way valve, air in the low-pressure circuit can be expelled while minimizing fuel loss.

[0004] However, particulate matter from the engine may sometimes enter the low-pressure fuel line of the diesel pump. Furthermore, considering weight reduction and cost, the pump housing is made of aluminum alloy. During processing, the soft material easily generates fine aluminum shavings and burrs, which are difficult to remove completely, especially inside deep channels, threads, and complex cavities within the aluminum housing. Therefore, the cleanliness of the housing is controlled as much as possible to a maximum of 400μm for metal particles. Larger particles from outside or inside the pump can have two consequences: 1. If particulate matter gets stuck between the steel ball 23 and the valve seat 20 of the one-way valve, the steel ball 23 cannot be reset normally under the action of the spring 24. A certain gap is generated between the steel ball 23 and the valve seat 20, which causes the one-way valve to not be completely closed. Some fuel flows back to the venturi through the gap. Under the condition of a certain fuel intake, the fuel delivered to the pump head end is relatively reduced, the fuel pump pressure is relatively low, and the fuel rail will not be able to be established or the pressure building time will be longer.

[0005] 2. Since the diameter of the exhaust port 22 is generally less than 1mm, the size of the exhaust port 22 is small, and particles of about 400μm can easily cause blockage of the exhaust port. Since the one-way valve is press-fitted into the oil return channel of the housing, once the exhaust port 22 on the one-way valve is blocked, it is difficult to repair or replace the part. Air forms air resistance in the low-pressure channel, which eventually leads to the fuel not being able to be delivered to the pump head area, the rail pressure being difficult to build up, and the engine being unable to start or having difficulty starting. Utility Model Content

[0006] This utility model addresses the existing technical problems by providing a pressure regulating valve with venting function for diesel pumps.

[0007] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A pressure regulating valve with exhaust function for a diesel pump includes a valve body, a ball, a compression spring and a valve core. The valve body has a valve cavity, the ball and the compression spring are installed in the valve cavity, and the valve core is slidably installed in the valve cavity. The ball and the valve core are respectively located at the two ends of the compression spring. A return oil hole one is provided on the side wall of the valve cavity. The valve core has a communicating oil inlet hole, an exhaust return oil hole and a return oil hole two. The oil inlet hole and the exhaust return oil hole are arranged along the axial direction of the valve core, and the return oil hole two is arranged on the side wall of the valve core.

[0008] Based on the above technical solution, the present invention can be further improved as follows: Preferably, the outer wall of the valve core is provided with a circumferential shoulder, and a sealing surface is provided on the circumferential shoulder, the sealing surface cooperating with the inner wall of the valve cavity.

[0009] Preferably, the included angle α of the sealing surfaces is 90°-120°.

[0010] Preferably, one or more oil return holes are provided, and the total flow cross-sectional area of ​​the oil return holes is a fixed value.

[0011] Preferably, there are two oil return holes, and the diameter of the second oil return hole is φ0.5mm-φ0.6mm.

[0012] Preferably, the valve body is provided with a plurality of oil drain holes evenly distributed in the circumferential direction, the oil drain holes are located at the same end as the valve core, and the oil drain holes are connected to the valve cavity.

[0013] Preferably, the diameter of the drain hole is φ2.8mm-φ4mm.

[0014] Preferably, both ends of the exhaust oil return hole are provided with flared openings.

[0015] Preferably, the diameter of the exhaust oil return hole is φ0.4mm-φ0.6mm.

[0016] Preferably, the valve body is detachably installed in the return oil passage of the diesel pump body, and a sealing ring is provided between the valve body and the return oil passage.

[0017] The beneficial effects of this utility model are as follows: By setting a valve body and a valve core, and providing an oil inlet, an exhaust return oil hole, and a return oil hole on the valve core, the pressure regulating valve not only has a pressure regulating function, but also effectively discharges air from the low-pressure oil circuit when the diesel pump is working, preventing air resistance caused by air accumulation, ensuring that fuel can be smoothly delivered to the pump head area, thereby stabilizing the rail pressure and ensuring normal engine operation. By integrating the exhaust and return oil functions into the pressure regulating valve, the number of parts is reduced, saving manufacturing costs. Simultaneously, the exhaust return oil hole, with flared ends at both ends, minimizes fuel loss during exhaust, improving fuel utilization. Furthermore, the valve body is detachably installed in the return oil channel of the diesel pump body, facilitating maintenance and replacement, further reducing operating costs. Attached Figure Description

[0018] Figure 1 This is a three-dimensional schematic diagram of the pressure regulating valve of this utility model installed on the diesel pump body; Figure 2 This is a cross-sectional view of the pressure regulating valve of this utility model installed on the diesel pump body. Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a schematic diagram of the valve core of this utility model; Figure 5 This is a schematic diagram of the pressure regulating valve of this utility model when it is at the second-stage opening pressure; Figure 6 This is a schematic diagram of the pressure regulating valve of this utility model in an oil supply system; Figure 7 This is a schematic diagram of a check valve in the prior art; Figure 8 for Figure 7 Enlarged diagram of point B in the middle.

[0019] The attached diagram is labeled as follows: 1. Diesel pump body; 2. Valve body; 21. Oil return hole one; 22. Oil drain hole; 3. Ball; 4. Compression spring; 5. Valve core; 51. Oil inlet hole; 52. Exhaust oil return hole; 53. Oil return hole two; 54. Sealing surface; 6. Oil inlet channel; 7. Oil return channel; 8. Oil drain channel; 9. Oil inlet connector; 10. Oil pump; 11. Venturi pipeline; 12. Fuel tank. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. The terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0022] like Figures 1 to 6 As shown, this utility model discloses a pressure regulating valve with exhaust function for a diesel pump, including a valve body 2, a ball 3, a compression spring 4, and a valve core 5. The valve body 2 has a valve cavity, the ball 3 and the compression spring 4 are installed in the valve cavity, and the valve core 5 is slidably installed in the valve cavity. The ball 3 and the valve core 5 are respectively located at both ends of the compression spring 4. The side wall of the valve cavity is provided with a return oil hole 21. The valve core 5 is provided with a communicating oil inlet hole 51, an exhaust return oil hole 52, and a second return oil hole 53. The oil inlet hole 51 and the exhaust return oil hole 52 are arranged along the axial direction of the valve core 5. The second return oil hole 53 is located on the side wall of the valve core 5. The diameter of the exhaust return oil hole 52 is φ0.4mm-φ0.6mm to ensure the discharge of air in the low-pressure circuit and to minimize fuel loss. In this embodiment, the diameter of the exhaust return oil hole 52 is φ0.4mm.

[0023] Furthermore, the outer wall of the valve core 5 is provided with a circumferential shoulder in the shape of a platform, and an inclined sealing surface 54 is provided on the circumferential shoulder. The sealing surface 54 mates with the inner wall of the valve cavity. Furthermore, the included angle α of the sealing surface 54 is 90°-120°, and the machining tolerance of the included angle α is 0-1°. This allows for a tighter fit between the sealing surface 54 and the inner wall of the valve cavity, effectively preventing fuel leakage from the sealing surface 54 under high pressure, thereby ensuring the sealing performance of the pressure regulating valve during operation and improving the stability and reliability of the entire fuel supply system. At the same time, this included angle design also facilitates machining and assembly, reducing production costs.

[0024] One or more oil return holes 53 are provided, and the total flow cross-sectional area of ​​the oil return holes 53 is a constant. The flow cross-sectional area of ​​the oil return holes 53 is calculated using the formula S=πD. 2 / 4×n, where n is the number of return oil holes 53, meaning the flow cross-sectional area of ​​one return oil hole 53 is equal to the total flow cross-sectional area of ​​multiple return oil holes 53. By reasonably setting the number and flow cross-sectional area of ​​the return oil holes 53, the flow rate of the pressure regulating valve during the oil return process can be precisely controlled, thereby achieving precise regulation of the oil supply system pressure. In this embodiment, there are two return oil holes 53, with a diameter of φ0.5mm-φ0.6mm. By keeping the total flow area of ​​the return oil holes 53 a constant value, the amount of oil returning through the return oil holes 53 is kept consistent, thus ensuring the stability and consistency of the system's oil return.

[0025] The valve body 2 is circumferentially provided with a plurality of drain holes 22, which are located at the same end as the valve core 5 and communicate with the valve cavity. By providing the drain holes 22, excess fuel in the valve cavity can be discharged in a timely manner, ensuring the stability of the system pressure. At the same time, the circumferentially evenly arranged drain holes 22 ensure pressure balance throughout the valve cavity, improving the working stability and reliability of the pressure regulating valve. In this example, three drain holes 22 are circumferentially evenly arranged, with a diameter of φ2.8mm-φ4mm, ensuring that the drain volume meets the requirements of the fuel supply system.

[0026] Both ends of the exhaust return port 52 are provided with flared openings. This allows for smoother exhaust and return processes. When air enters the exhaust return port 52 from the low-pressure oil circuit, the flared opening design reduces airflow resistance, allowing air to be expelled quickly. When fuel returns through the exhaust return port 52, the flared opening also reduces fuel flow resistance, improving return efficiency. Furthermore, the flared openings at both ends of the exhaust return port 52 effectively prevent particulate matter from accumulating within it, reducing the risk of blockage and ensuring the long-term stable operation of the pressure regulating valve.

[0027] The ball 3 is a steel ball. During installation, the valve core 5 and compression spring 4 are first installed sequentially in the valve cavity. Then, the ball 3 is pressed into the open end of the valve cavity with an interference fit to ensure a seal and prevent the ball 3 from coming out. In use, the valve body 2 is detachably installed in the return oil channel of the diesel pump body 1 via external threads. When the pressure regulating valve malfunctions or requires maintenance, it can be easily removed from the diesel pump body for repair or replacement, reducing maintenance difficulty and cost. Multiple sealing rings are provided between the valve body 2 and the return oil channel to ensure a reliable seal between the valve body 2 and the return oil channel of the diesel pump body, preventing fuel leakage from the installation interface and ensuring the stability and reliability of the fuel supply system.

[0028] When the pressure regulating valve is not open, the air in the low-pressure oil circuit enters the valve chamber of the valve body 2 through the oil inlet channel 6 of the diesel pump body 1, and is discharged from the low-pressure oil circuit through the exhaust return oil hole 52 on the valve core 5.

[0029] Fuel enters the fuel pump 10 through the fuel inlet connector 9. As the fuel pump 10 pumps more fuel, the fuel is delivered to the pressure regulating valve through the fuel inlet channel 6. When the pressure regulating valve reaches the first opening pressure, the oil pressure on the valve core 5 is greater than the spring force of the compression spring 4. The valve core 5 moves to the left, so that the return oil hole 53 and the exhaust return oil hole 52 of the valve core 5 are connected to the return oil channel 7 in the diesel pump body 1. The fuel in the return oil channel 7 is delivered to the vehicle's fuel tank 12 through the Venturi pipe 11. When the oil pressure pumped by the oil pump 10 reaches the secondary opening pressure of the pressure regulating valve, the valve core 5 continues to move to the left under the action of the oil pressure. The valve chamber of the valve body 2 is connected to the oil drain channel 8 of the diesel pump body 1 through the oil drain hole 22, and the fuel returns to the vehicle's fuel tank 12 through the oil drain channel 8.

[0030] When the fuel pressure decreases or the fuel supply stops, the compression spring 4 returns to its original shape, pushing the ball 3 and valve core 5 to reset, closing the return oil passage 7, and ensuring the stability of the fuel supply system pressure.

[0031] This invention integrates the functions of two separate components (exhaust valve and return valve) into a single pressure regulating valve, reducing the number of parts and lowering material and manufacturing costs. Simultaneously, the reduced number of parts simplifies the assembly process, improves production efficiency, and further reduces production costs. By precisely controlling the exhaust and return processes, the pressure regulating valve effectively prevents airflow and ensures smooth fuel delivery to the pump head area, thereby achieving stable rail pressure establishment. Furthermore, the precise control of the pressure regulating valve's sealing performance and flow cross-sectional area further enhances the stability and reliability of the fuel supply system.

[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pressure regulating valve with venting function for a diesel pump, characterized in that, The valve includes a valve body (2), a ball (3), a compression spring (4), and a valve core (5). The valve body (2) has a valve cavity. The ball (3) and the compression spring (4) are installed in the valve cavity. The valve core (5) is slidably installed in the valve cavity. The ball (3) and the valve core (5) are located at the two ends of the compression spring (4). The side wall of the valve cavity is provided with a return oil hole 1 (21). The valve core (5) is provided with a communicating oil inlet hole (51), an exhaust return oil hole (52), and a return oil hole 2 (53). The oil inlet hole (51) and the exhaust return oil hole (52) are arranged along the axial direction of the valve core (5). The return oil hole 2 (53) is arranged on the side wall of the valve core (5).

2. The pressure regulating valve with venting function for a diesel pump according to claim 1, characterized in that, The outer wall of the valve core (5) is provided with a circumferential shoulder, and a sealing surface (54) is provided on the circumferential shoulder, which cooperates with the inner wall of the valve cavity.

3. The pressure regulating valve with venting function for a diesel pump according to claim 2, characterized in that, The included angle α of the sealing surface (54) is 90°-120°.

4. The pressure regulating valve with venting function for a diesel pump according to claim 1, characterized in that, The second oil return hole (53) is provided with one or more, and the total flow cross-sectional area of ​​the second oil return hole (53) is a fixed value.

5. The pressure regulating valve with venting function for a diesel pump according to claim 4, characterized in that, There are two oil return holes (53), and the diameter of the oil return holes (53) is φ0.5mm-φ0.6mm.

6. The pressure regulating valve with venting function for a diesel pump according to claim 2, characterized in that, The valve body (2) is provided with a plurality of oil drain holes (22) evenly distributed in the circumferential direction. The oil drain holes (22) and the valve core (5) are located at the same end, and the oil drain holes (22) are connected to the valve cavity.

7. The pressure regulating valve with venting function for a diesel pump according to claim 6, characterized in that, The diameter of the drain hole (22) is φ2.8mm-φ4mm.

8. The pressure regulating valve with venting function for a diesel pump according to claim 1, characterized in that, Both ends of the exhaust return oil hole (52) are provided with flared openings.

9. The pressure regulating valve with venting function for a diesel pump according to claim 1, characterized in that, The diameter of the exhaust return oil hole (52) is φ0.4mm-φ0.6mm.

10. The pressure regulating valve for a diesel pump with venting function according to any one of claims 1 to 9, characterized in that, The valve body (2) is detachably installed in the oil return channel of the diesel pump body (1), and a sealing ring is provided between the valve body (2) and the oil return channel.

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