A pressure limiting device for a diesel engine lubrication system

Abstract

The utility model discloses a diesel engine lubricating system pressure limiting device belongs to pressure limiting valve technical field, pressure limiting device sets up in the end of diesel engine ontology main oil way, and is located pressure sensor's oil flow upstream, including the valve core of coaxial arrangement, spring, adjusting bolt and pressure limiting valve valve body, the lower part of valve core passes through the oil drain hole of oil drain cavity and extends to the inside of main oil way, spring is set up in the valve core outside, adjusting bolt upper portion is sleeved in pressure limiting valve valve body lower extreme, and is connected with pressure limiting valve valve body screw thread, pressure limiting valve valve body upper end is equipped with the opening, and this opening is closed by screw plug. The utility model can effectively prolong the service life of pressure limiting device, and the valve core of pressure limiting device is well -centered, can well adjust the pressure of diesel engine lubricating system.

Description

Technical Field

[0001] This utility model relates to the field of pressure relief valve technology, and in particular to a pressure relief device for a diesel engine lubrication system. Background Technology

[0002] A pressure limiting device is a device used to control the pressure of a diesel engine's lubrication system. Current pressure limiting devices have some shortcomings in use: they are inconvenient to adjust and replace, have a short service life, and cannot effectively regulate system pressure. Therefore, a new pressure limiting device is proposed.

[0003] The pressure stability of the main oil passage in a diesel engine's lubrication system directly affects the engine's reliability and lifespan. Traditional pressure limiting devices mostly use spring valve structures with fixed opening pressures, which have the following drawbacks: (1) Inconvenient adjustment: The opening pressure is determined by the pre-compression of the spring, and different specifications of springs or shims need to be replaced to adjust it, which is cumbersome and has low precision. (2) Risk of seal failure: The valve core and valve seat often use a planar seal. After long-term use, wear can easily lead to poor sealing, causing abnormal drop in oil pressure. (3) Location limitations: If it is set downstream of the pressure sensor, the sensor cannot monitor the overpressure state, which poses a risk of protection lag. (4) Poor stability: Springs are prone to stress relaxation in high-temperature oil, which leads to drift of opening pressure.

[0004] Therefore, there is an urgent need for a pressure limiting device that is precisely adjustable, reliably sealed, and rationally laid out to improve the accuracy and durability of pressure control in lubrication systems. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a pressure limiting device for a diesel engine lubrication system, which can extend the service life of the pressure limiting device, is easy to adjust and replace, and has a well-aligned valve core structure, which can effectively regulate the system pressure.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A pressure limiting device for a diesel engine lubrication system is provided. The pressure limiting device is located at the end of the main oil passage of the diesel engine body and upstream of the oil flow of the pressure sensor. It includes a valve core, a spring, an adjusting bolt, and a pressure limiting valve body arranged coaxially. The lower part of the valve core extends through the oil drain hole of the oil drain chamber into the interior of the main oil passage. The spring is sleeved on the outside of the valve core. The upper part of the adjusting bolt is fitted onto the lower end of the pressure limiting valve body and is threadedly connected to the pressure limiting valve body. The upper end of the pressure limiting valve body has an opening, which is closed by a screw plug.

[0007] A further improvement of this utility model is that the adjusting bolt is engaged with the pressure relief valve body through an external thread. Rotating the adjusting bolt can change its axial displacement relative to the upper end face of the pressure relief valve body, thereby adjusting the preload of the spring to precisely control the opening pressure of the valve core.

[0008] A further improvement of this utility model is that the external thread of the adjusting bolt is a fine thread with a pitch of no more than 1.25 mm.

[0009] A further improvement of this utility model is that the top of the adjusting bolt is provided with a groove for adjusting its height.

[0010] A further improvement of this utility model is that: a spherical sealing structure is provided at the bottom of the valve core, and a conical valve seat is provided at the corresponding position in the main oil passage; the spherical sealing structure and the conical valve seat cooperate to form a line contact seal.

[0011] A further improvement of this utility model is that the cone angle of the conical valve seat is 90°±2° and the surface roughness Ra≤0.4μm.

[0012] A further improvement of this utility model is that the surface of the spherical sealing structure is covered with a wear-resistant alloy layer or a nitriding treatment layer.

[0013] A further improvement of this utility model is that a sealing gasket is provided between the screw plug and the upper opening of the pressure limiting valve body.

[0014] A further improvement of this utility model is that: the two ends of the spring are provided with a flattened structure, and the coaxiality error between the spring axis and the valve core axis is less than 0.1mm.

[0015] A further improvement of this utility model is that the spring is made of high-temperature alloy spring steel wire, the material of which conforms to the SAE 6150 standard, and the surface is shot peened.

[0016] The technological advancements achieved by this utility model due to the adoption of the above technical solution are as follows: 1. This utility model is located at the end of the main oil passage and upstream of the pressure sensor, ensuring that the pressure sensor monitors the actual pressure before the valve core opens in real time, avoiding overpressure damage to the pressure sensor, and at the same time, the end pressure relief is more thorough; an installation hole is opened on the main oil passage on one side of the oil drain chamber, and a conical valve seat is set on the installation hole. The valve core is installed on the conical valve seat through the oil drain hole of the oil drain chamber. A spring and adjusting bolt are fitted on the outside of the valve core. The adjusting bolt is engaged with the pressure limiting valve body through a fine thread (pitch ≤ 1.25mm). By finely adjusting its axial displacement, the spring preload can be changed, realizing continuous high-precision adjustment of the opening pressure (such as ±0.05MPa) without replacing parts; making the pressure limiting device simple to maintain, accurate in pressure adjustment, efficient, and space-saving.

[0017] 2. This utility model has a groove at the top of the adjusting bolt to facilitate tool operation, which improves the adjustment efficiency.

[0018] 3. In this utility model, the spherical sealing structure at the bottom of the valve core forms a line contact seal with the conical valve seat (cone angle 90°±2°) of the main oil passage, resulting in stress concentration and better sealing performance than planar sealing. The surface roughness of the valve seat Ra≤0.4μm, combined with the wear-resistant alloy layer / nitriding layer of the spherical surface, significantly reduces wear and extends the sealing life by >30%.

[0019] 4. The spring in this utility model is made of SAE 6150 high-temperature resistant alloy steel wire, which is shot peened to improve fatigue resistance and ensure long-term stable operation in a 120℃ oil environment; the two ends of the spring are ground flat and the coaxiality with the pressure relief valve is <0.1mm, eliminating jamming or abnormal wear caused by off-center load.

[0020] 5. In this utility model, a sealing gasket is added between the screw plug and the pressure relief valve body to eliminate the risk of external oil leakage. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of a pressure limiting device for a diesel engine lubrication system provided in an embodiment of this utility model; Among them, 1. Adjusting bolt; 2. Pressure relief valve body; 3. Valve core; 4. Spring; 5. Plug; 6. Sealing gasket; 7. Pressure sensor; 8. Main oil passage; 9. Oil drain chamber; X. The height of the top of the adjusting bolt above the mounting surface. Detailed Implementation

[0022] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this utility model are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0023] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1 As shown, a pressure limiting device for a diesel engine lubrication system is provided. The pressure limiting device is located at the end of the main oil passage 8 of the diesel engine body and upstream of the oil flow of the pressure sensor 7. It includes a valve core 3, a spring 4, an adjusting bolt 1, and a pressure limiting valve body 2 arranged coaxially. The lower part of the valve core 3 extends through the oil drain hole of the oil drain chamber 9 into the interior of the main oil passage 8. The spring 4 is sleeved on the outside of the valve core 3. The upper part of the adjusting bolt 1 is sleeved on the lower end of the pressure limiting valve body 2 and is threadedly connected to the pressure limiting valve body 2. The upper end of the pressure limiting valve body 2 has an opening, which is closed by a screw plug 5.

[0025] Furthermore, the adjusting bolt 1 is engaged with the pressure relief valve body 2 through its external thread. Rotating the adjusting bolt 1 can change its axial displacement relative to the upper end face of the pressure relief valve body 2, thereby adjusting the preload of the spring 4 to precisely control the opening pressure of the valve core 3.

[0026] Furthermore, the external thread of the adjusting bolt 1 is a fine thread with a pitch of no more than 1.25 mm. The adjusting bolt 1 engages with the valve body 2 through the fine thread, and its axial displacement can be finely adjusted to change the preload of the spring 4, thereby achieving continuous high-precision adjustment of the opening pressure (e.g., ±0.05 MPa) without the need to replace parts.

[0027] Furthermore, the top of the adjusting bolt 1 is provided with a groove for adjusting its height. The groove facilitates tool operation and improves adjustment efficiency.

[0028] Furthermore, the bottom of the valve core 3 is provided with a spherical sealing structure, and a conical valve seat is provided at the corresponding position in the main oil passage 8. The spherical sealing structure and the conical valve seat cooperate to form a line contact seal, which concentrates the contact stress and has better sealing performance than a planar seal.

[0029] Furthermore, the cone angle of the conical valve seat is 90°±2°, the surface roughness Ra≤0.4μm, and combined with the wear-resistant alloy layer / nitriding layer on the spherical surface, it significantly reduces wear and extends the sealing life by >30%.

[0030] Furthermore, the surface of the spherical sealing structure is covered with a wear-resistant alloy layer or a nitrided layer.

[0031] Furthermore, a sealing gasket 6 is provided between the screw plug 5 and the upper opening of the pressure relief valve body 2 to prevent the risk of external oil leakage.

[0032] Furthermore, the two ends of the spring 4 are provided with a flattened structure, and the coaxiality error between the axis of the spring 4 and the axis of the valve core 3 is less than 0.1mm, eliminating jamming or abnormal wear caused by off-center load.

[0033] Furthermore, spring 4 is made of high-temperature alloy spring steel wire, the material of which conforms to the SAE 6150 standard, and the surface is shot peened. The shot peening treatment improves the fatigue strength and ensures long-term stable operation in a 120℃ oil environment. Specifically, a pressure limiting device is installed at the end of the main oil passage 8 of the diesel engine body, making full use of space in its external structure; the optimal route is selected for its placement, maximizing the simplicity and efficiency of system pressure regulation and improving efficiency. To achieve the above objectives, a separate design for the pressure limiting device and sensor is adopted, making it convenient and quick to use and maintain. The pressure sensor 7 is located at the rear end of the pressure limiting device, within the same main oil passage 8, ensuring accurate pressure detection.

[0034] like Figure 1 As shown, adjusting bolt 1 provides installation guidance for valve core 3 and spring 4, preventing tilting or eccentricity of valve core 3 and spring 4 during operation. The external thread of adjusting bolt 1 controls the height X of the adjusting bolt tip above the mounting surface. By rotating and adjusting this height X, the opening pressure of valve core 3 is precisely controlled and adjusted, thereby controlling the pressure of the lubrication system. The contact surface between valve core 3 and the mounting hole on the main oil passage 8 is designed as a spherical surface, ensuring good alignment between valve core 3 and the mounting hole, compensating for installation eccentricity or vibration, and facilitating sealing. The pressure relief valve body 2 is designed as an open type, allowing for easy and quick adjustment of the height X of the adjusting bolt tip above the mounting surface during diesel engine operation by removing the plug 5. This reduces the possibility of reduced lifespan, pressure regulation performance, and sealing effect caused by disassembly and reassembly.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A pressure limiting device for a diesel engine lubrication system, characterized in that: The pressure limiting device is located at the end of the main oil passage (8) of the diesel engine body and upstream of the oil flow of the pressure sensor (7); it includes a valve core (3), a spring (4), an adjusting bolt (1) and a pressure limiting valve body (2) arranged coaxially; the lower part of the valve core (3) extends through the oil drain hole of the oil drain chamber (9) into the interior of the main oil passage (8); the spring (4) is sleeved on the outside of the valve core (3); the upper part of the adjusting bolt (1) is sleeved on the lower end of the pressure limiting valve body (2) and is threadedly connected to the pressure limiting valve body (2); the upper end of the pressure limiting valve body (2) has an opening, which is closed by a screw plug (5).

2. The pressure limiting device for a diesel engine lubrication system according to claim 1, characterized in that: The adjusting bolt (1) is engaged with the pressure relief valve body (2) through external thread. Rotating the adjusting bolt (1) can change its axial displacement relative to the upper end face of the pressure relief valve body (2), thereby adjusting the preload of the spring (4) to precisely control the opening pressure of the valve core (3).

3. A pressure limiting device for a diesel engine lubrication system according to claim 2, characterized in that: The external thread of the adjusting bolt (1) is a fine thread with a pitch of no more than 1.25 mm.

4. A pressure limiting device for a diesel engine lubrication system according to claim 2, characterized in that: The top of the adjusting bolt (1) is provided with a groove for adjusting its height.

5. A pressure limiting device for a diesel engine lubrication system according to claim 1, characterized in that: The valve core (3) is provided with a spherical sealing structure at the bottom, and a conical valve seat is provided at the corresponding position in the main oil passage (8). The spherical sealing structure and the conical valve seat cooperate to form a line contact seal.

6. A pressure limiting device for a diesel engine lubrication system according to claim 5, characterized in that: The cone angle of the conical valve seat is 90°±2°, and the surface roughness Ra≤0.4μm.

7. A pressure limiting device for a diesel engine lubrication system according to claim 5, characterized in that: The surface of the spherical sealing structure is covered with a wear-resistant alloy layer or a nitriding layer.

8. A pressure limiting device for a diesel engine lubrication system according to claim 1, characterized in that: A sealing gasket (6) is provided between the screw plug (5) and the upper opening of the pressure relief valve body (2).

9. A pressure limiting device for a diesel engine lubrication system according to claim 1, characterized in that: The spring (4) has a flattened structure at both ends, and the coaxiality error between the axis of the spring (4) and the axis of the valve core (3) is less than 0.1 mm.

10. A pressure limiting device for a diesel engine lubrication system according to claim 1, characterized in that: The spring (4) is made of high-temperature alloy spring steel wire, and its material conforms to the SAE 6150 standard and its surface is shot blasted.

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