Flow metering structure
By setting a skeleton oil seal in the flow metering structure of the fuel injection pump to seal the clearance between the pole shoe and the valve core, the problem of fuel leakage is solved, and good rail pressure control and processing efficiency are improved.
Patent Information
- Application Number
- CN202422637456.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-10-30
AI Technical Summary
The flow metering structure of the existing fuel injection pump has fuel leakage when in the closed state, causing rail pressure fluctuations. In addition, the processing and assembly process is cumbersome and the cost is high.
A flow metering structure is adopted, and a first skeleton oil seal is provided between the pole shoe and the valve core to seal the gap between the mating parts, avoid fuel leakage, and simplify the processing and assembly process.
It achieves no fuel leakage in the closed state, ensures better rail pressure control, reduces the pump body processing and assembly procedures, improves processing efficiency, and reduces costs.
Smart Images
Figure CN223359290U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of fuel flow measurement, and in particular to a flow measurement structure. Background Art
[0002] The fuel injection pump uses a flow metering mechanism to measure fuel delivery, thereby achieving optimal rail pressure control and ultimately precise fuel injection. Currently, flow metering mechanisms often utilize a slide valve. However, when the flow metering mechanism is closed, fuel leakage between the two mating components of the slide valve can affect rail pressure fluctuations. This necessitates the use of a zero-flow orifice in the fuel injection pump to return the leaked fuel to the tank, or the installation of an electronically controlled pressure-limiting valve at the end of the common rail pipe to dynamically adjust rail pressure.
[0003] However, installing a zero-flow orifice in an injection pump involves multiple steps, including pump body machining, press-fitting the zero-flow orifice, and deburring, making the process cumbersome. Furthermore, the fuel inlet pressure of the injection pump must be strictly controlled during operation to prevent high-pressure fuel from entering the high-pressure pump directly through the zero-flow orifice, bypassing the metering unit and causing rail pressure fluctuations. Installing an electronically controlled pressure-limiting valve on the common rail increases costs due to the additional actuator. Utility Model Content
[0004] In view of this, the purpose of this application is to provide a flow metering structure that can seal the gap between the pole piece and the valve core, thereby preventing fuel from leaking through the gap. The specific solution is as follows:
[0005] On the one hand, the present application provides a flow metering structure, comprising:
[0006] A housing; the housing having a coil therein;
[0007] A moving iron core assembly; the moving iron core assembly is partially located in the internal space of the housing, and under the action of the coil, the moving iron core assembly moves along its axial direction;
[0008] a pole shoe located in the interior space of the housing; at least a portion of the movable iron core assembly is located in the interior space of the pole shoe, the pole shoe having a through oil inlet, the axial direction of the oil inlet being perpendicular to the axial direction of the movable iron core assembly;
[0009] A valve core and a spring base are located in the interior space of the pole shoe; one end of the movable iron core assembly is connected to the first end of the valve core, and the second end of the valve core is connected to the spring base via a spring; the outer surface of the valve core contacts the inner surface of the pole shoe;
[0010] The first skeleton oil seal; the first skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the first skeleton oil seal is in contact with the pole shoe, the second end of the first skeleton oil seal is in contact with the first side surface of the oil inlet, and the outer surface of the first skeleton oil seal is in contact with the pole shoe.
[0011] Optionally, the inner diameter of the spring base is larger than the outer diameter of the valve core.
[0012] Optionally, it also includes:
[0013] The second skeleton oil seal; the second skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the second skeleton oil seal contacts the second side surface of the oil inlet, the second end of the second skeleton oil seal contacts the spring base, and the outer surface of the second skeleton oil seal contacts the pole shoe.
[0014] Optionally, it also includes:
[0015] At least one first limiting structure; the first limiting structure is located between the second end of the first skeleton oil seal and the first side surface of the oil inlet.
[0016] Optionally, it also includes:
[0017] At least one second limiting structure; the second limiting structure is located between the first end of the second skeleton oil seal and the second side surface of the oil inlet.
[0018] Optionally, the valve core moves in the spring base along the axial direction of the valve core.
[0019] Optionally, the first skeleton oil seal includes a metal skeleton and rubber surrounding the metal skeleton.
[0020] Optionally, the valve core has at least one hole.
[0021] Optionally, the spring base and the pole shoe are in interference connection.
[0022] Optionally, it also includes:
[0023] A gasket is located on the end surface of the pole shoe, and the gasket surrounds the moving iron core assembly.
[0024] An embodiment of the present application provides a flow metering structure, including a shell, a moving iron core assembly, a pole shoe, a valve core, a spring base and a first skeleton oil seal; a coil is provided in the shell; the moving iron core assembly is partially located in the internal space of the shell; under the action of the coil, the moving iron core assembly moves along its axial direction; the pole shoe is located in the internal space of the shell; at least a part of the moving iron core assembly is located in the internal space of the pole shoe, the pole shoe has a through oil inlet, and the axial direction of the oil inlet is perpendicular to the axial direction of the moving iron core assembly; the valve core and the spring base are located in the internal space of the pole shoe; one end of the moving iron core assembly is connected to the first end of the valve core, and the second end of the valve core is connected to the spring base through a spring; the outer surface of the valve core contacts the inner surface of the pole shoe; the first skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the first skeleton oil seal contacts the pole shoe, the second end of the first skeleton oil seal contacts the first side surface of the oil inlet, and the outer surface of the first skeleton oil seal contacts the pole shoe. This solution can seal the gap between the pole shoe and the valve core by setting a first skeleton oil seal, thereby preventing fuel from leaking through the gap between the pole shoe and the valve core, ensuring that there is no fuel leakage when the oil metering structure is in the closed state, achieving better rail pressure control, reducing the processing and assembly steps of the pump body, improving processing efficiency, and eliminating the need to add unnecessary electronically controlled actuators. It has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0026] Figure 1 A schematic diagram of a flow metering structure provided by an embodiment of the present application is shown;
[0027] Figure 2 A partial schematic diagram of a flow metering structure provided by an embodiment of the present application is shown;
[0028] Figure 3 A schematic diagram of another flow metering structure provided in an embodiment of the present application is shown. DETAILED DESCRIPTION
[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.
[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0031] Secondly, this application is described in detail with reference to schematic diagrams. When describing the embodiments of this application, for ease of explanation, cross-sectional views of device structures may be partially enlarged and not to scale. Furthermore, these schematic diagrams are merely illustrative and should not limit the scope of protection of this application. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.
[0032] For ease of understanding, a flow metering structure provided in an embodiment of the present application is described in detail below with reference to the accompanying drawings.
[0033] refer to Figure 1 As shown, it is a schematic diagram of a flow metering structure provided in an embodiment of the present application. The flow metering structure may include a housing 1, a pole shoe 2, a moving iron core assembly 3, a valve core 4, a spring base 5 and a skeleton oil seal 6, a limiting structure 7 and a spring 8.
[0034] refer to Figure 2 FIG. 1 is a partial schematic diagram of a flow metering structure provided by an embodiment of the present application. The skeleton oil seal 6 includes a first skeleton oil seal 62 and a second skeleton oil seal 61. The limiting structure 7 includes a first limiting structure 72 and a second limiting structure 71. Figure 3 As shown, a schematic diagram of another flow metering structure provided by an embodiment of the present application, the valve core 4 has a hole 11, and it is shown that the fuel enters from the oil inlet 10 and flows out from the oil outlet 20 of the spring base 5.
[0035] Specifically, the flow metering structure can control the movement of the valve core 4 through electromagnetic force generated by an electrical signal to adjust the fuel flow entering the flow metering structure. In this application, a spool-type flow metering structure is used as an example. A spool valve is a device that controls the flow rate by changing the cross-sectional area of the fluid flow through the sliding movement of the valve core 4.
[0036] A coil is provided in the housing 1, and the coil can be energized or de-energized. The housing 1 forms an internal space, and the movable iron core assembly 3 can be partially located in the internal space, while another portion of the movable iron core assembly 3 can be located outside. When the electronic control unit receives a command, it energizes the coil, thereby generating an electromagnetic force. Under the action of the electromagnetic force, the movable iron core assembly 3 can move along its own axial direction, that is, it can move downward. When the coil is not energized, the first end of the movable iron core assembly 3 can also be in contact with the housing. After the coil is energized, the first end will separate from the housing.
[0037] The pole shoe 2 is located in the interior space of the housing 1. The pole shoe 2 is a non-moving part and its position in the housing 1 is fixed. The pole shoe 2 has a through oil inlet, and the axial direction of the oil inlet is perpendicular to the axial direction of the moving iron core assembly 3. That is, if the axial direction of the moving iron core assembly 3 is the vertical direction, the axial direction of the oil inlet is the horizontal direction, and the fuel flows horizontally in the oil inlet. For example, refer to Figure 1 shown.
[0038] In addition, at least a portion of the moving iron core assembly 3 is located in the inner space of the pole shoe 2 , that is, the other end (ie, the second end) of the moving iron core assembly 3 can extend into the inner space of the pole shoe 2 .
[0039] The valve core 4 and the spring base 5 are also located in the internal space of the pole shoe 2. One end (i.e., the second end) of the moving iron core assembly 3 is connected to the first end of the valve core 4, and the second end of the valve core 4 is connected to the spring base 5 through a spring; the outer surface of the valve core 4 contacts the inner surface of the pole shoe 2.
[0040] That is, the end of the moving iron core assembly 3 connected to the housing 1 can be recorded as the first end, and the end connected to the valve core 4 can be recorded as the second end. Figure 1 In the example, the first end of the movable iron core assembly 3 is at the top, and the second end is at the bottom. Furthermore, the first end of the valve core 4, located at the top, contacts the second end of the movable iron core assembly 3, while the second end of the valve core 4, located at the bottom, is connected to the spring base 5 via a spring. Thus, the electromagnetic force generated by energizing the coil causes the movable iron core assembly 3 to move axially, which in turn pushes the valve core 4 to move axially.
[0041] Among them, the spring base 5 is used to support the spring, refer to Figure 1 The spring can make the valve core 4 move upward by utilizing the compression force of the spring when the coil is not energized. When the coil is energized to push the valve core 4 to move, the spring is compressed. When the coil is de-energized, the valve core 4 returns to its initial state under the action of the spring.
[0042] In a possible implementation, the valve core 4 has at least one hole 11, which may be one or more holes arranged along the circumferential direction. The cross-sectional shape of the hole 11 may be an isosceles triangle, a rectangle, or an irregular shape. Figure 3 As shown, the shape of the hole 11 is a triangle.
[0043] When the electromagnetic force of the movable iron core assembly 3 pushes the valve core 4, the hole 11 in the valve core 4 and the oil inlet on the pole piece 2 form an overlapping flow area, thereby allowing the fuel to flow. As the valve core 4 continues to move, the flow area will continue to change (increase or decrease), and the fuel flow rate will also change accordingly. Therefore, by controlling the reciprocating motion of the valve core 4, fuel metering is achieved.
[0044] refer to Figure 3 As shown, when the hole 11 of the valve core 4 just passes through the first limiting structure 72, the fuel begins to flow, and when the hole 11 is about to pass through the second limiting structure 71, the fuel is about to stop flowing.
[0045] exist Figure 2 In the figure, a first gap 12 and a second gap 13 are shown. The first gap 12 and the second gap 13 are essentially the gaps between the pole piece 2 and the valve core 4. In the related art, when the flow metering structure is in the closed state, fuel leakage will occur in the gap between the pole pieces.
[0046] In order to solve the problem of fuel leakage, a first skeleton oil seal 62 can be set between the pole shoe 2 and the valve core 4. The first skeleton oil seal 62 is sleeved on the outer surface of the valve core 4, the first end of the first skeleton oil seal 62 contacts the pole shoe 2, the second end of the first skeleton oil seal 62 contacts the first side surface of the oil inlet, and the outer surface of the first skeleton oil seal 62 contacts the pole shoe 2.
[0047] In short, the first skeleton oil seal 62 is positioned around the outer periphery of the valve core 4, between the valve core 4 and the pole piece 2. This means that the outer surface of the first skeleton oil seal 62 contacts the pole piece 2. Furthermore, since fuel leakage originates near the fuel inlet 10, the first skeleton oil seal 62 is positioned close to the fuel inlet 10. Specifically, its two ends contact one side of the fuel inlet 10 and the pole piece 2, respectively. This seals the first gap 12, preventing fuel leakage therefrom.
[0048] This solution can seal the gap between the pole shoe 2 and the valve core 4 by providing a first skeleton oil seal 62, thereby preventing fuel from leaking through the gap. This ensures that there is no fuel leakage when the oil metering structure is in the closed state, achieves better rail pressure control, reduces the processing and assembly steps of the pump body, improves processing efficiency, and does not require the addition of redundant electronically controlled actuators. It has a simple structure and low cost.
[0049] In a possible implementation, the inner diameter of the spring base 5 may be larger than the outer diameter of the valve core 4. Figure 2 As shown, the inner diameter of the spring base 5 can be slightly larger than the outer diameter of the valve core 4, and there is a small distance between the inner wall of the spring base 5 and the outer surface of the valve core 4. In one possible implementation, the flow metering structure can further include a second skeleton oil seal 61. The second skeleton oil seal 61 is sleeved on the outer surface of the valve core 4. The first end of the second skeleton oil seal 61 contacts the second side surface of the oil inlet 10, the second end of the second skeleton oil seal 61 contacts the spring base 5, and the outer surface of the second skeleton oil seal 61 contacts the pole piece 2.
[0050] Specifically, the second skeleton oil seal 61 is also positioned around the outer periphery of the valve core 4, between the valve core 4 and the pole piece 2. This means that the outer surface of the second skeleton oil seal 61 contacts the pole piece 2. Furthermore, since fuel leakage originates near the fuel inlet 10, the second skeleton oil seal 61 is positioned near the other side of the fuel inlet 10. This means that one end of the second skeleton oil seal 61 can contact the other side surface (i.e., the second side surface) of the fuel inlet. Furthermore, since the inner diameter of the spring base 5 is larger than the outer diameter of the valve core 4, the spring base 5 provides support for the second skeleton oil seal 61, allowing the other end of the second skeleton oil seal 61 to contact the spring base 5.
[0051] In short, the second skeleton oil seal 61 can be clamped between the spring base 5 and the oil inlet 10, so as to seal the second gap 13 and prevent fuel from leaking from the second gap 13. In this way, the first gap 12 and the second gap 13 can be completely sealed by the first skeleton oil seal 62 and the second skeleton oil seal 61. These two skeleton oil seals achieve sealing by cooperating with the pole piece 2 and the valve core 4. After sealing, the fuel cannot leak through the gap between the valve core 4 and the pole piece 2.
[0052] In one possible implementation, in order to prevent the first skeleton oil seal 62 from generating axial movement and thereby affecting the seal during the movement of the valve core 4, the flow metering structure may further include at least one first limiting structure 72, and the first limiting structure 72 is located between the second end of the first skeleton oil seal 62 and the first side surface of the oil inlet.
[0053] Specifically, the first limiting structure 72 is used to position the first skeleton oil seal 62 and can be clamped between the first skeleton oil seal 62 and the oil inlet. In this way, one end of the first skeleton oil seal 62 is close to the pole shoe 22, and the other end is close to the first limiting structure 72, thereby avoiding the position of the first skeleton oil seal 62 from changing.
[0054] For example, the first skeleton oil seal 62 can be an elastic retaining ring with an opening, which can be installed in the groove of the pole shoe 2, such as Figure 2 As shown, two first skeleton oil seals 62 are shown, which are respectively located in the grooves on both sides of the valve core 4.
[0055] In one possible implementation, in order to prevent the second skeleton oil seal 61 from generating axial movement and affecting the sealing when the valve core 4 moves, the flow metering structure may also include at least one second limiting structure 71, and the second limiting structure 71 is located between the first end of the second skeleton oil seal 61 and the second side surface of the oil inlet.
[0056] The second limiting structure 71 is used to position the second skeleton oil seal 61. One end of the second skeleton oil seal 61 can be close to the second limiting structure 71, and the other end can be close to the spring base 5, thereby ensuring that the second skeleton oil seal 61 does not move. Figure 2 As shown, the two second skeleton oil seals 61 are respectively located in the grooves on both sides of the valve core 4.
[0057] In a possible implementation, when the inner diameter of the spring base 5 is larger than the outer diameter of the valve core 4, the valve core 4 moves in the spring base 5 along the axial direction of the valve core 4. Figure 2 As shown, when the valve core 4 moves in the axial direction, it can enter the interior of the spring base 5 and fully utilize the space in the spring base 5.
[0058] In one possible implementation, the first and second skeleton oil seals 62 and 61 may include a metal frame and rubber surrounding the metal frame. This improves the support of the first and second skeleton oil seals 62 and 61, preventing deformation of the seals during movement of the valve core 4 and fuel leakage.
[0059] In a possible implementation, the spring base 5 may be interference-connected with the pole shoe 2 , thereby firmly fixing the spring base 5 in the inner space of the pole shoe 2 .
[0060] In one possible implementation, the flow metering structure may further include a gasket 9 located on the end surface of the pole shoe 2, which surrounds the movable iron core assembly 3. Specifically, the gasket 9 is installed on the end surface of the pole shoe 2 to isolate the magnetic field, preventing the movable iron core assembly 3 from directly adsorbing onto the pole shoe 2 under the action of electromagnetic force, thereby affecting the return motion of the valve core 4 and causing uncontrolled oil flow.
[0061] An embodiment of the present application provides a flow metering structure, including a shell, a moving iron core assembly, a pole shoe, a valve core, a spring base and a first skeleton oil seal; a coil is provided in the shell; the moving iron core assembly is partially located in the internal space of the shell; under the action of the coil, the moving iron core assembly moves along its axial direction; the pole shoe is located in the internal space of the shell; at least a part of the moving iron core assembly is located in the internal space of the pole shoe, the pole shoe has a through oil inlet, and the axial direction of the oil inlet is perpendicular to the axial direction of the moving iron core assembly; the valve core and the spring base are located in the internal space of the pole shoe; one end of the moving iron core assembly is connected to the first end of the valve core, and the second end of the valve core is connected to the spring base through a spring; the outer surface of the valve core contacts the inner surface of the pole shoe; the first skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the first skeleton oil seal contacts the pole shoe, the second end of the first skeleton oil seal contacts the first side surface of the oil inlet, and the outer surface of the first skeleton oil seal contacts the pole shoe. This solution can seal the gap between the pole shoe and the valve core by setting a first skeleton oil seal, thereby preventing fuel from leaking through the gap between the pole shoe and the valve core, ensuring that there is no fuel leakage when the oil metering structure is in the closed state, achieving better rail pressure control, reducing the processing and assembly steps of the pump body, improving processing efficiency, and eliminating the need to add unnecessary electronically controlled actuators. It has a simple structure and low cost.
[0062] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.
[0063] The above is only a preferred embodiment of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of protection of the technical solution of the present application.
Claims
1. A flow metering structure, characterized in that: include: case; The housing has a coil therein; Moving iron core assembly; The movable iron core assembly is partially located in the inner space of the housing, and under the action of the coil, the movable iron core assembly moves along its axial direction; a pole shoe located in the interior space of the housing; at least a portion of the movable iron core assembly is located in the interior space of the pole shoe, the pole shoe having a through oil inlet, the axial direction of the oil inlet being perpendicular to the axial direction of the movable iron core assembly; A valve core and a spring base are located in the interior space of the pole shoe; one end of the movable iron core assembly is connected to the first end of the valve core, and the second end of the valve core is connected to the spring base via a spring; the outer surface of the valve core contacts the inner surface of the pole shoe; First skeleton oil seal; The first skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the first skeleton oil seal contacts the pole shoe, the second end of the first skeleton oil seal contacts the first side surface of the oil inlet, and the outer surface of the first skeleton oil seal contacts the pole shoe.
2. The flow metering structure according to claim 1, characterized in that: The inner diameter of the spring base is greater than the outer diameter of the valve core.
3. The flow metering structure according to claim 2, characterized in that: Also includes: Second skeleton oil seal; The second skeleton oil seal is sleeved on the outer surface of the valve core, the first end of the second skeleton oil seal contacts the second side surface of the oil inlet, the second end of the second skeleton oil seal contacts the spring base, and the outer surface of the second skeleton oil seal contacts the pole shoe.
4. The flow metering structure according to claim 1, characterized in that: Also includes: At least one first limiting structure; the first limiting structure is located between the second end of the first skeleton oil seal and the first side surface of the oil inlet.
5. The flow metering structure according to claim 3, characterized in that: Also includes: At least one second limiting structure; the second limiting structure is located between the first end of the second skeleton oil seal and the second side surface of the oil inlet.
6. The flow metering structure according to claim 2, characterized in that: The valve core moves in the spring seat along the axial direction of the valve core.
7. The flow metering structure according to claim 1, characterized in that: The first skeleton oil seal includes a metal skeleton and rubber surrounding the metal skeleton.
8. The flow metering structure according to claim 1, characterized in that: The valve core has at least one hole.
9. The flow metering structure according to claim 1, characterized in that: The spring base is interference-connected to the pole shoe.
10. The flow metering structure according to claim 1, characterized in that: Also includes: A gasket is located on the end surface of the pole shoe, and the gasket surrounds the moving iron core assembly.