Oil pump provided with pressure limiting valve
By designing small and large drain ports in the oil pump pressure relief valve assembly, multi-stage pressure relief is achieved, solving the problem of fixed pressure relief value in existing pressure relief valves, stabilizing lubrication system pressure, reducing oil consumption, and protecting system components.
Patent Information
- Application Number
- CN202521105091.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2035-05-30
AI Technical Summary
Current pressure relief valves can only be set to a fixed pressure relief value, which cannot achieve multi-stage pressure relief, leading to pressure fluctuations in the lubrication system and potential risks of component damage.
Design an oil pump pressure relief valve assembly, including a plunger, a spring, and a plug. The valve orifice is provided with a small oil drain port and a large oil drain port. By pushing the plunger to move through different oil pressure values, multi-stage pressure relief is achieved, with the small oil drain port and the large oil drain port opening and closing respectively.
It achieves multi-stage pressure relief, stabilizes lubrication system pressure, reduces oil consumption, avoids system shock, and protects the oil pump and lubrication system components.
Smart Images
Figure CN223881249U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the lubricating system of automobile engine, concretely relates to a kind of oil pump of installation limited pressure valve. BACKGROUND
[0002] Oil pump pressure limiting valve is usually installed on oil pump or main oil passage, and its function is to limit the maximum oil pressure of lubricating system, to prevent oil pump overload or lubricating system component damage caused by excessive pressure. When oil pressure exceeds the set value, the pressure limiting valve opens, and part of the oil is discharged back to the oil pan or pump inlet, reducing the system pressure. By dynamically adjusting the pressure relief amount, it is ensured that the main oil passage pressure is within a safe range, which meets the lubrication requirements and avoids the impact of pressure fluctuation on the system. The working process of pressure limiting valve can be summarized as follows: oil pressure rises → overcomes spring pre-tightening force → valve opens → pressure relief → oil pressure falls → valve closes, and the cycle is adjusted to stabilize the pressure.
[0003] The pressure limiting valve can only open the valve to start pressure relief when the oil pressure reaches the set pressure relief value. As long as the oil pressure is less than the set pressure relief value, the valve is always in the closed state. In the prior art, each pressure limiting valve can only set one pressure relief value. Although this pressure relief value can be changed by adjusting the spring pre-tightening force, once the pressure relief value is determined, it remains unchanged during operation. UTILITY MODEL CONTENTS
[0004] The technical problem to be solved by the utility model is to provide an oil pump with a limited pressure valve, which can realize multi-stage pressure relief.
[0005] To solve the above technical problems, the utility model adopts the following technical solutions: an oil pump with a limited pressure valve, comprising a pump body and a pressure limiting valve assembly installed on the pump body, the pump body is provided with a pump cavity, an oil outlet passage and a valve hole, the pressure limiting valve assembly comprises a plunger, a spring and a plug, the valve hole has a small oil discharge port and a large oil discharge port on its hole wall from inside to outside, the distance between the small oil discharge port and the plug is greater than the distance between the large oil discharge port and the plug, the small oil discharge port and the large oil discharge port are both communicated with the low pressure area of the pump cavity, and the plunger can close the small oil discharge port and the large oil discharge port under the pre-tightening force of the spring; the inner side end of the valve hole is communicated with the oil outlet passage, the oil outlet passage is communicated with the high pressure area of the pump cavity, and the high pressure oil in the oil outlet passage can act on the inner side end of the plunger.
[0006] In the above technical solution, since the valve hole wall is provided with a small oil drain port and a large oil drain port from the inside to the outside, two different pressure relief values will be formed, thereby enabling multi-stage pressure relief. When the oil pressure in the outlet channel reaches the first pressure relief value, the high-pressure oil will push the plunger to compress the spring and move outwards from the valve orifice until the small drain port on the orifice wall is opened. Some of the high-pressure oil flows into the low-pressure area of the pump chamber through the small drain port. If the oil pressure in the outlet channel then drops, the plunger will move inwards from the valve orifice under the preload of the spring, closing the small drain port. When the oil pressure in the outlet channel continues to rise above the first pressure relief value and reaches the second pressure relief value, the high-pressure oil will push the plunger to compress the spring and move outwards from the valve orifice. The small drain port on the orifice wall is opened first, but the pressure relief effect is limited. The high-pressure oil continues to push the plunger outwards from the valve orifice until the large drain port is opened. Some of the high-pressure oil flows into the low-pressure area of the pump chamber through the small drain port and the large drain port. If the oil pressure in the outlet channel then drops, the plunger will move inwards from the valve orifice under the preload of the spring, closing the large drain port and the small drain port in sequence.
[0007] In one embodiment, the oil outlet passage communicates with the valve hole and is located on the same central axis. The diameter of the oil outlet passage is smaller than the diameter of the valve hole, forming a stepped surface at the connection between the oil outlet passage and the valve hole. Under the preload of the spring, the inner end of the plunger abuts against the stepped surface to seal the oil. The sidewall of the oil outlet passage has a through hole connecting to the high-pressure area of the pump chamber. Designing the oil outlet passage and the valve hole on the same central axis facilitates machining.
[0008] In one embodiment, the number of small drain ports is one, and the number of large drain ports is one or more.
[0009] In one embodiment, the plunger comprises a cylindrical portion and a rod-shaped portion, with the opening of the cylindrical portion facing the oil outlet, and the inner end of the spring fitted onto the rod-shaped portion. This structure maximizes the spring diameter; a larger spring diameter generally results in better stability.
[0010] In one embodiment, an vent hole is provided on the wall of the valve orifice near the blockage location.
[0011] In one embodiment, the oil pump is a fixed displacement pump. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the oil pump structure in an embodiment of the present utility model;
[0013] Figure 2 for Figure 1 Schematic diagram of the DD line cross-section structure in the middle;
[0014] Figure 3 for Figure 1 Schematic diagram of the EE line cross-section structure in the diagram;
[0015] Figure 4 A plunger structure schematic view in the embodiment of the utility model;
[0016] The reference signs are:
[0017] 1, pump body; 2, plunger; 3, spring; 4, plug; 5, small oil drain port; 6, large oil drain port; 7, oil outlet; 8, exhaust hole. DETAILED DESCRIPTION
[0018] For the convenience of understanding of those skilled in the art, the utility model is further explained below in combination with embodiments and drawings, and the content mentioned in the embodiments is not a limitation on the utility model.
[0019] It needs to be explained in advance that in the utility model, unless another explicit provision and limitation, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0020] As Figures 1 to 4 shown, an oil pump with a pressure limiting valve, the oil pump is a constant displacement pump, comprising a pump body 1 and a pressure limiting valve assembly mounted on the pump body 1, the pump body 1 is provided with a pump cavity, an oil outlet 7 and a valve hole, the pressure limiting valve assembly comprises a plunger 2, a spring 3 and a plug 4, a small oil drain port 5 and a large oil drain port 6 are sequentially arranged on the hole wall of the valve hole from inside to outside, the distance between the small oil drain port 5 and the plug 4 is greater than the distance between the large oil drain port 6 and the plug 4, the small oil drain port 5 and the large oil drain port 6 are both communicated with the low pressure area of the pump cavity, the plunger 2 can close the small oil drain port 5 and the large oil drain port 6 under the pre-tightening force of the spring 3, the number of the small oil drain port 5 is one, and the number of the large oil drain port 6 is one or more; the inner side end of the valve hole is communicated with the oil outlet 7, the oil outlet 7 is communicated with the high pressure area of the pump cavity, and the high pressure oil in the oil outlet 7 can act on the inner side end of the plunger 2; an exhaust hole 8 is arranged on the hole wall of the valve hole close to the plug 4.
[0021] In the above technical scheme, since the hole wall of the valve hole is sequentially provided with the small oil drain hole 5 and the large oil drain hole 6 from inside to outside, two different pressure relief values are formed, multi-stage pressure relief is realized, and the fuel consumption of the engine can be further reduced. When the oil pressure in the oil outlet channel 7 reaches the first pressure relief value, the high-pressure oil pushes the plunger 2 to compress the spring 3 and move to the outside of the valve hole, until the small oil drain hole 5 on the hole wall is opened, and part of the high-pressure oil flows into the low-pressure area of the pump cavity through the small oil drain hole 5. Then, if the oil pressure in the oil outlet channel 7 falls, the plunger 2 moves to the inside of the valve hole under the pre-tightening force of the spring 3, and the small oil drain hole 5 is closed. When the oil pressure in the oil outlet channel 7 continuously rises and exceeds the first pressure relief value and reaches the second pressure relief value, the high-pressure oil pushes the plunger 2 to compress the spring 3 and move to the outside of the valve hole, the small oil drain hole 5 on the hole wall is first opened but the pressure relief effect is limited, the high-pressure oil continues to push the plunger 2 to move to the outside of the valve hole, until the large oil drain hole 6 is opened, and part of the high-pressure oil flows into the low-pressure area of the pump cavity through the small oil drain hole 5 and the large oil drain hole 6. Then, if the oil pressure in the oil outlet channel 7 falls, the plunger 2 moves to the inside of the valve hole under the pre-tightening force of the spring 3, and the large oil drain hole 6 and the small oil drain hole 5 are sequentially closed.
[0022] As shown in Figure 2 , 3 , in order to facilitate processing, the oil outlet channel 7 and the valve hole are designed on the same center axis in the embodiment, so that the oil outlet channel 7 and the valve hole are connected to form a stepped hole, the hole diameter of the oil outlet channel 7 is smaller than the hole diameter of the valve hole, a step surface is formed at the connection of the oil outlet channel 7 and the valve hole, and the inside end of the plunger 2 abuts against the step surface to seal oil under the pre-tightening force of the spring 3. The side wall of the oil outlet channel 7 is provided with a through hole connected to the high-pressure area of the pump cavity.
[0023] As shown in Figure 3 , 4 , the plunger 2 of the pressure limiting valve is composed of a cylindrical part and a rod-shaped part, the opening of the cylindrical part faces the oil outlet channel 7, and the inside end of the spring 3 is sleeved on the rod-shaped part. This structure can maximize the coil diameter of the spring 3, and the larger the coil diameter of the spring 3, the better the stability.
[0024] The above embodiment is a preferred implementation scheme of the utility model, in addition to this, the utility model can also be realized in other ways, and any obvious replacement without departing from the technical scheme concept is within the protection scope of the utility model.
[0025] In order to make those skilled in the art more conveniently understand the improvements of the utility model relative to the prior art, some drawings and descriptions of the utility model have been simplified, and some other elements are also omitted in the application file for the sake of clarity, and those skilled in the art should realize that these omitted elements can also constitute the content of the utility model.
Claims
1. An oil pump equipped with a pressure limiting valve, comprising a pump body (1) and a pressure limiting valve assembly mounted on the pump body (1), characterized in that, The pump body (1) is provided with a pump cavity, an oil outlet (7) and a valve hole, the pressure limiting valve assembly comprises a plunger (2), a spring (3) and a plug (4), the hole wall of the valve hole is sequentially provided with a small oil leakage port (5) and a large oil leakage port (6) from inside to outside, the spacing between the small oil leakage port (5) and the plug (4) is greater than the spacing between the large oil leakage port (6) and the plug (4), the small oil leakage port (5) and the large oil leakage port (6) are communicated with the low pressure area of the pump cavity, the plunger (2) can close the small oil leakage port (5) and the large oil leakage port (6) under the pre-tightening force of the spring (3); the inner side end of the valve hole is communicated with the oil outlet (7), the oil outlet (7) is communicated with the high pressure area of the pump cavity, and the high pressure oil in the oil outlet (7) can act on the inner side end of the plunger (2).
2. The oil pump with a limited pressure valve mounted according to claim 1, characterized in that: The oil outlet (7) is communicated with the valve hole and located on the same center axis, the hole diameter of the oil outlet (7) is smaller than the hole diameter of the valve hole, so that a step surface is formed at the connection between the oil outlet (7) and the valve hole, and the inner side end of the plunger (2) is abutted on the step surface to seal oil under the pre-tightening force of the spring (3); the side wall of the oil outlet (7) is provided with a through hole communicated to the high pressure area of the pump cavity.
3. The oil pump with a limited pressure valve mounted according to claim 1 or 2, characterized in that: The number of the small oil leakage port (5) is one, and the number of the large oil leakage port (6) is one or more.
4. The oil pump with a limited pressure valve mounted according to claim 1 or 2, characterized in that: The plunger (2) is composed of a cylindrical part and a rod-shaped part, the opening of the cylindrical part faces the oil outlet (7), and the inner side end of the spring (3) is sleeved on the rod-shaped part.
5. The oil pump with a limited pressure valve mounted according to claim 1 or 2, characterized by: An exhaust hole (8) is arranged on the hole wall of the valve hole and close to the plug (4).
6. The oil pump with a limited pressure valve mounted according to claim 1 or 2, characterized by: The oil pump is a constant displacement pump.