Drive mechanism for high-pressure fuel pump and high-pressure fuel pump
By designing a pressure balance path in the driving mechanism of the high-pressure fuel pump, lubricating oil can flow between different chambers, the problem of engine oil leakage is solved, pressure balance is achieved, and the stability and environmental friendliness of the system are enhanced.
Patent Information
- Application Number
- CN202421899559.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-08-07
AI Technical Summary
In existing high-pressure fuel pumps, engine oil is prone to leakage, especially when the speed suddenly increases, which leads to intensified wear of the oil seal, causing engine oil leakage and affecting system integrity.
A driving mechanism for high-pressure fuel pumps is designed, including a camshaft chamber, an axial seal chamber and a spring chamber, through a pressure balance path to allow lubricating oil to flow between these chambers, dynamically maintaining pressure balance and avoiding overpressure.
By redistributing the pressure, keeping the pressure in the axial seal chamber within a safe range, reducing oil leakage, reducing losses and contamination, and enhancing the efficiency, robustness and environmental friendliness of the system.
Smart Images
Figure CN222879801U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a driving mechanism for a high-pressure fuel pump. In addition, the present application also relates to a high-pressure fuel pump. Such a high-pressure fuel pump is generally used to pressurize fuel so as to pump it into an engine in a high-pressure form. Background Art
[0002] The application scenarios of high-pressure fuel pumps in industry are very wide. They can be used in fixed machinery or mobile machinery, such as vehicles. An exemplary application scenario may be set in the fuel injection system of the engine for the vehicle. As a secondary oil pump, it further pressurizes the fuel brought by the primary oil pump (generally a low-pressure pump) so that the fuel is directly injected into the cylinder of the engine in the form of high pressure. This high-pressure fuel can be better vaporized and dispersed into the cylinder, thereby improving the overall combustion efficiency of the engine, which has great technical advantages.
[0003] However, the high-pressure fuel pump provided in the prior art still has some technical problems. For example, the oil carried in the high-pressure fuel pump is sometimes easy to leak out. This undesirable phenomenon is more likely to occur when the speed of the high-pressure fuel pump is suddenly increased (for example, multiple times and repeatedly). Specifically, when the speed of the fuel pump is suddenly increased, the pressure in the pump will increase, which may cause the oil seal to wear more severely, and this wear will eventually cause the oil seal to fail and leak. This oil leakage can be identified by observing the housing of the high-pressure fuel pump from the outside. The leaked oil contaminates the high-pressure fuel pump itself and even affects other parts and / or components around the high-pressure fuel pump, which may further affect the integrity of the entire system.
[0004] In view of but not limited to the above-mentioned various situations and / or problems, it is desirable to provide a new type of high-pressure fuel pump to solve or at least alleviate the above-mentioned problems. Utility Model Content
[0005] The present application aims to provide a drive mechanism for a high-pressure fuel pump, and a high-pressure fuel pump, which are advantageous in at least one aspect over the prior art.
[0006] To this end, the present application provides, in one aspect, a driving mechanism for a high-pressure fuel pump, characterized in that it comprises: a camshaft chamber for accommodating a camshaft, an axial sealing chamber positioned adjacent to the camshaft chamber and accommodating an axial sealing assembly,
[0007] A spring chamber accommodating a spring separated by a slider relative to a camshaft chamber, and a pressure balance passage, wherein the pressure balance passage is configured to connect the axial sealing chamber and the spring chamber fluidly so that lubricating oil can flow between the axial sealing chamber and the spring chamber, thereby dynamically maintaining the pressure balance between the axial sealing chamber and the spring chamber.
[0008] In an exemplary embodiment, the pressure balance passage is configured to match one or more of the following factors: speed, flow rate, and / or travel distance of the slide block of the high pressure fuel pump.
[0009] In an exemplary embodiment, the pressure balance passage includes: an axial seal portion opening positioned at and open to the axial seal chamber; a spring portion opening positioned at and open to the spring chamber; and a fluid line connecting the axial seal portion opening and the spring portion opening.
[0010] In an exemplary embodiment, the axial seal opening is opened at a position of the side cover of the high-pressure fuel pump adjacent to the axial seal chamber by drilling.
[0011] In an exemplary embodiment, the axial seal opening is arranged at an upper edge of the axial seal assembly above the camshaft.
[0012] In an exemplary embodiment, the axial seal assembly is formed in a semi-annular shape opening inwardly, and the axial seal portion opening is arranged adjacent to the semi-annular opening of the axial seal assembly.
[0013] In an exemplary embodiment, the driving mechanism for the high-pressure fuel pump further includes: a protective member configured to be fastened to an outer wall of a cylinder of the high-pressure fuel pump and define a protective space, wherein the protective space is configured to allow a fluid pipeline to pass therethrough and protect the fluid pipeline.
[0014] In an exemplary embodiment, the driving mechanism for the high-pressure fuel pump further includes: an opening control valve, which is arranged on the fluid pipeline and configured to control the opening of the fluid pipeline.
[0015] In an exemplary embodiment, the driving mechanism for the high-pressure fuel pump also includes: a pressure sensor, which is configured to detect the pressure of at least one of the following: a camshaft chamber, an axial seal chamber, and a spring chamber; wherein the driving mechanism is configured to control the opening of the fluid pipeline through an opening control valve according to the pressure detected by the pressure sensor.
[0016] On the other hand, the present application also provides a high-pressure fuel pump, characterized in that it includes: a driving mechanism for the high-pressure fuel pump as described above; and a plunger; wherein the driving mechanism is configured to drive the plunger of the high-pressure fuel pump to perform reciprocating motion.
[0017] The driving mechanism for a high-pressure fuel pump and the high-pressure fuel pump according to the present application have at least the following advantages: by redistributing the pressure, the overpressure existing in the axial sealing chamber of the high-pressure fuel pump can be rebalanced, so that the pressure in the axial sealing chamber always fluctuates smoothly within a range not exceeding the maximum threshold pressure of the axial seal. In this way, the problem of oil leakage of the high-pressure fuel pump can be alleviated or even eliminated, the loss and pollution can be reduced, and the efficiency, robustness and / or environmental friendliness of the high-pressure fuel pump and even the system in which it is located can be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A high-pressure fuel pump according to an exemplary embodiment of the present application is shown, and specifically a schematic diagram of a driving mechanism of the high-pressure fuel pump is shown.
[0019] Figure 2 A cross-sectional view is shown of a drive mechanism of a high-pressure fuel pump according to an exemplary embodiment of the present application.
[0020] Figure 3 Further shown in an enlarged manner Figure 2 The driving mechanism in the device has an axial sealing chamber. DETAILED DESCRIPTION
[0021] Some feasible implementations of the present application are described below with reference to the accompanying drawings. It should be noted that the drawings are not drawn to scale. Some details may be enlarged for clear display, and some unnecessary details are omitted.
[0022] according to Figure 1 and Figure 2 , an exemplary embodiment of a high-pressure fuel pump is shown. Specifically, a driving mechanism 100 of the high-pressure fuel pump is shown. The driving mechanism 100 of the high-pressure fuel pump is configured to drive a plunger (not shown) of the high-pressure fuel pump to reciprocate, thereby providing pressure to the fuel and transmitting it to the fuel rail to inject the fuel into the engine.
[0023] The driving mechanism includes a stationary part, a moving part and a pressure balance passage. The stationary part includes a pump body 101 and a cylinder body 102 located above the pump body, a side cover 103, and an axial seal assembly 13. The pump body 101, the cylinder body 102, the side cover 103 and the axial seal assembly 13 together define an internal space. The internal space contains moving parts, including but not limited to: a camshaft 1, and a cam 11, a bearing 12, a slider 2, and a spring 3 on the camshaft. The internal space includes a camshaft chamber 300, an axial seal chamber 400 and a spring chamber 500. The details are as follows.
[0024] The camshaft 1 as a drive shaft partially protrudes from the pump body 101 at the upstream end ( Figure 2 The pump body 101 is shown as the left side and connected to a power supply device (not shown), so as to be driven to rotate, thereby driving the cam 11 on the camshaft 1 located inside the pump body 101 to rotate. The internal space where the camshaft 1 is located is referred to as the "camshaft chamber 300" in this article.
[0025] The camshaft 1 is rotatably fixed to the inner wall of the pump body 101 via the bearing 12. In addition, an axial seal assembly 13 is arranged on the side cover 103 to isolate the internal space from the outside. The internal space where the axial seal assembly 13 is located is referred to as the "axial seal chamber 400" in this article.
[0026] The cam 11 of the camshaft 1 abuts against the lower end of the slider 2. A spring 3 capable of generating a spring force in a vertical direction is arranged above the slider 2. The upper end of the spring 3 is fixed to the cylinder 102. The lower end of the spring 3 abuts against the slider 2. Through the rotational movement of the camshaft 1, the cam 11 and the spring 3 drive the slider 2 to reciprocate up and down. The internal space where the spring 3 is located is referred to as the "spring chamber 500" in this article.
[0027] In actual use, when the cam surface of the cam 11 moves from its lowest point to its highest point, the cam 11 abuts against the lower end of the slider 2 and pushes the entire slider 2 upward from the lowest position (bottom dead center) to the highest position (top dead center), and the spring 3 is compressed upward, thereby generating elastic potential energy, which can be called the upward stroke (first stroke); when the cam surface of the cam 11 moves from its highest point to its lowest point, the elastic potential energy of the spring 2 is released, and the spring 3 pushes the upper end of the slider 2 downward from the highest position (top dead center) to the lowest position (bottom dead center) and the slider 2 also abuts against the cam 11 at the same time, which can be called the downward stroke (second stroke). Through the up and down reciprocating motion of the slider 2, the fuel is sucked in and pushed out, thereby pressurizing the fuel.
[0028] In order to reduce the wear between the moving parts, lubricating oil is often poured into the inner space, and the lubricating oil is distributed in the camshaft chamber 300, the axial seal chamber 400 and the spring chamber 500 respectively.
[0029] As described above, the drive mechanism 100 further includes a pressure balance passage. The pressure balance passage is configured to connect the axial seal chamber 400 and the spring chamber 500 to each other so that lubricating oil can flow between the axial seal chamber 400 and the spring chamber 500, thereby dynamically maintaining the pressure balance between the axial seal chamber 400 and the spring chamber 500. The pressure balance passage can be configured to match the speed, flow rate, and / or travel distance of the slider of the high-pressure fuel pump.
[0030] The number of the pressure balancing passages may be one or more. For example, the number of the pressure balancing passages may be determined according to the speed, flow rate, and / or travel distance of the slider of the high-pressure fuel pump.
[0031] like Figure 1 As shown exemplarily, the pressure balance passage includes an axial sealing portion opening 301 (first opening) positioned and opened to the axial sealing chamber 400, a spring portion opening 302 (second opening) positioned and opened to the spring chamber 500, and a fluid pipeline 303 connecting the axial sealing portion opening 301 and the spring portion opening 302.
[0032] The axial sealing portion opening 301 can be obtained by drilling a hole directly in the side cover 103 (which is connected to the pump body 101 ) at a position adjacent to the axial sealing chamber 400 .
[0033] For example, in some cases, since the portion of the axial seal chamber 400 located above the camshaft 1 is closer to the slider 2 than the portion located below the camshaft 1, the pressure imbalance problem of the portion located above the camshaft 1 is more serious. Accordingly, the axial seal opening 301 can be arranged at the upper edge of the axial seal assembly 13 (located above the camshaft 1). In this way, the pressure can be dynamically balanced more timely and efficiently. Another advantage is that the length of the fluid pipeline 303 can be shortened, thereby reducing material and manufacturing costs to save energy.
[0034] like Figure 3 As shown, the axial seal assembly 13 can be formed to open inward (toward the interior of the high-pressure fuel pump, for example Figure 2 The axial seal opening 301 is in the shape of a semi-circular shape (shown as the right side in FIG. 1 ). Accordingly, the axial seal opening 301 can be arranged to be adjacent to the semi-circular opening of the axial seal assembly 13. In this way, the fluid in the axial seal chamber 400 can be more conveniently connected to the fluid in the spring chamber 500 quickly and efficiently, thereby balancing the pressure between the axial seal chamber 400 and the spring chamber 500.
[0035] The spring opening 302 can be arranged on the pump body 101 and positioned above the top dead center of the slider 2. In this way, the axial sealing chamber 400 fluid can be conveniently connected to the spring chamber 500. In addition, the length of the fluid pipeline 303 can be shortened, thereby reducing material and manufacturing costs to save energy.
[0036] It is understood that the fluid pipeline 303 can be made of any suitable material as required. For example, the fluid pipeline 303 can be made of a flexible material with a certain hardness (rigidity).
[0037] The inner diameter (throughput) of the fluid line 303 may be configured to be determined according to requirements (including but not limited to the flow rate of fuel to be pumped, pump speed, etc.).
[0038] In addition, it can be understood that the driving mechanism 100 of the high-pressure fuel pump can also include a protective member (not shown). According to the needs (for example, the length of the fluid pipeline, the positioning of the axial sealing portion opening 301 and / or the positioning of the spring portion opening 302, etc.), the protective member can be implemented as one or more protective members. The protective member can be configured to be fastened to the outer wall of the cylinder body 102 and define a protective space. The protective space is configured to allow the fluid pipeline 303 to pass therethrough, thereby protecting the fluid pipeline 303, for example, protecting it from unnecessary vibration or displacement caused by interference from the external environment. In addition to the outer wall of the cylinder body 102, the protective member can also be set on the pump body 101, including but not limited to: one side of the pump body 101 close to the axial sealing assembly 13 ( Figure 2 ), and / or the side of the pump body 101 away from the axial seal assembly 13 ( Figure 2 The protective member may be formed into a shape and configuration of a protective ring, or any other suitable shape and configuration.
[0039] For example, the driving mechanism 100 of the high-pressure fuel pump may further include an opening control valve disposed on the fluid pipeline 303 to control the opening of the fluid pipeline 303, thereby controlling the rate of the dynamic pressure balancing process.
[0040] For example, the driving mechanism 100 of the high-pressure fuel pump may further include a pressure sensor. The pressure sensor may be configured to detect the pressure of at least one of the following: the camshaft chamber 300, the axial seal chamber 400, and the spring chamber 500. Accordingly, the opening of the fluid line 303 may be controlled by the opening control valve according to the pressure detected by the pressure sensor.
[0041] An engine can refer to any internal combustion engine that uses fuel as a combustion medium to convert internal energy into mechanical energy. This type of engine can generally be a diesel engine, or a gasoline engine, etc.
[0042] As used herein, the term “comprising” is open ended and includes one or more stated features, elements, components, or functions, but does not preclude the presence or addition of one or more other features, elements, components, functions, or combinations thereof.
[0043] The above description of the embodiments of the present application has been provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed. Within the scope of the present application, it is known that the various aspects, embodiments, examples and alternatives listed in the preceding paragraphs, claims and / or in the specification and drawings, in particular their individual features, can be carried out independently or in any combination. That is, all embodiments and / or the features of any embodiment can be in any way and / or combination unless these features are incompatible. It can be known that many modifications and changes are available to those skilled in the art. The selection and description of the embodiments are to properly explain the principles of the present invention and its practical application, so that other persons skilled in the art can understand the various embodiments of the present invention and the various modifications suitable for the intended specific use. The applicant reserves the right to change any originally submitted claims or submit any new claims accordingly, including modifying any originally submitted claims to be subordinate and / or incorporate any features of any other claims, although not originally required in this way.
Claims
1. A driving mechanism (100) for a high-pressure fuel pump, characterized in that: include: a camshaft chamber (300) for accommodating a camshaft (1), an axial seal chamber (400) positioned adjacent to the camshaft chamber (300) and accommodating an axial seal assembly (13), a spring chamber (500) spaced apart from the camshaft chamber (300) by the slider (2) and accommodating the spring (3), and A pressure balance passage is configured to connect the axial seal chamber (400) and the spring chamber (500) to each other so that lubricating oil can flow between the axial seal chamber (400) and the spring chamber (500), thereby dynamically maintaining the pressure balance between the axial seal chamber (400) and the spring chamber (500).
2. The drive mechanism (100) for a high-pressure fuel pump according to claim 1, characterized in that: The pressure balance passage is configured to match one or more of the following factors: speed, flow rate, and / or travel distance of the slide block of the high pressure fuel pump.
3. The drive mechanism (100) for a high-pressure fuel pump according to claim 1 or 2, characterized in that: The pressure balance passage comprises: an axial seal opening (301) located in and opening to the axial seal chamber (400); a spring portion opening (302) positioned within and opening into the spring chamber (500); and A fluid pipeline (303) connects the axial sealing portion opening (301) and the spring portion opening (302).
4. The driving mechanism (100) for a high-pressure fuel pump according to claim 3, characterized in that: The axial sealing portion opening (301) is opened at a position adjacent to the axial sealing chamber (400) of the side cover (103) of the high-pressure fuel pump by drilling.
5. The driving mechanism (100) for a high-pressure fuel pump according to claim 4, characterized in that: The axial sealing portion opening (301) is arranged at the upper edge of the axial sealing assembly (13) above the camshaft (1).
6. The drive mechanism (100) for a high-pressure fuel pump according to claim 4 or 5, characterized in that: The axial seal component (13) is formed into a semi-annular shape with an opening facing inward, and the axial seal portion opening hole (301) is arranged adjacent to the semi-annular opening of the axial seal component (13).
7. The driving mechanism (100) for a high-pressure fuel pump according to claim 3, characterized in that: Also includes: A protective member is configured to be fastened to the outer wall of a cylinder body (102) of a high-pressure fuel pump and define a protective space, wherein the protective space is configured to allow a fluid pipeline (303) to pass therethrough and protect the fluid pipeline (303).
8. The driving mechanism (100) for a high-pressure fuel pump according to claim 3, characterized in that: Also includes: An opening control valve is arranged on the fluid pipeline (303) and is configured to control the opening of the fluid pipeline (303).
9. The driving mechanism (100) for a high-pressure fuel pump according to claim 8, characterized in that: Also includes: A pressure sensor, wherein the pressure sensor is configured to detect the pressure of at least one of the following: a camshaft chamber (300), an axial seal chamber (400), and a spring chamber (500); wherein the drive mechanism is configured to control the opening of a fluid pipeline (303) through an opening control valve according to the pressure detected by the pressure sensor.
10. A high-pressure fuel pump, characterized in that: include: A drive mechanism (100) for a high-pressure fuel pump according to any one of claims 1 to 9; and Plunger; wherein the driving mechanism (100) is configured to drive the plunger of the high-pressure fuel pump to reciprocate.