Fixing and pressing device for oil sprayer
By setting the middle support block at the bottom of the injector fixing device and optimizing the position of the oil return hole, the loosening problem of the injector fixing device under the explosion-pressure alternating load and the spring overheating fatigue and fracture problems are solved, and more stable fixation and longer service life are achieved.
Patent Information
- Application Number
- CN202421781154.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-25
- Publication Date
- 2025-05-20
- Estimated Expiration
- 2034-07-25
AI Technical Summary
The existing injector fixing device is separated from the injector mounting surface under the combustion chamber explosion pressure alternating load, resulting in loosening and failure of the fastening stud, and insufficient cooling of the spring leads to overheating fatigue and fracture.
A fixed compression device for injectors is designed. By setting a base plane and a central support block at the bottom of the compression block, the bottom surface of the central support block is fitted with the thrust surface of the injector, the area of the pressure bearing surface of the compression block is reduced, the contact surface pressure is increased, and by optimizing the position of the oil return hole, the oil return is fully cooled.
It effectively avoids separation of the pressure-bearing surface of the pressure-bearing surface of the compressor and the installation surface of the fuel injector, prevents loosening and failure of the stud, and prevents the spring from being overheated and fatigued.
Smart Images
Figure CN222887070U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of fuel injectors, and particularly relates to a fuel injector fixing and pressing device. Background Art
[0002] In the prior art, as Figure 1 shown, the middle part of the pressing block 2 is sleeved and fixed on the fuel injector 4, and two fastening studs 3 are used to fix the pressing block 2 on the cylinder head 1, and then the fuel injector 4 is fixed on the cylinder head 1. Since the fuel injector 4 is located in the middle and the installation space is limited, the bearing surfaces of the pressing block 2 and the fuel injector 4 are the entire circle of the bottom surface of the pressing block (referred to as the bearing surface S of the pressing block) and the thrust surface of the fuel injector (referred to as the bearing surface of the fuel injector), respectively. The bearing area of the pressing block is large and the surface pressure is small. After the pressing block 2 is pressed, the pressing block 2 bends and deforms, and the deformation deflection is large, resulting in uneven contact between the pressing block 2 and the installation surface of the fuel injector 4. Under the alternating load of the combustion chamber explosion pressure, the bearing surface S of the pressing block creeps and separates from the thrust surface of the fuel injector, resulting in the loosening and failure of the fastening stud 3. And as Figure 1 shown, since the fuel injector leakage return hole 400 is opened at the lower part of the spring installation hole 102, the spring 401 is insufficiently cooled, resulting in overheating and fatigue fracture of the spring. Summary of the Utility Model
[0003] Aiming at the above defects of the prior art, the technical problem to be solved by the utility model is to provide a fuel injector fixing and pressing device, which can avoid the creep of the bearing surface of the pressing block and the separation from the installation surface of the fuel injector, avoid the loosening and failure of the stud, and can avoid the overheating and fatigue fracture of the spring.
[0004] To solve the above technical problems, the utility model adopts the following technical solutions:
[0005] A fuel injector fixing and pressing device includes a cylinder head, a pressing block and fastening studs. An injector installation hole for installing a fuel injector is provided on the cylinder head. The pressing block is provided with a pressing block center hole and two fastening stud installation holes. The fastening studs pass through the fastening stud installation holes to fix the pressing block and the fuel injector on the cylinder head. A spring installation hole is provided on the fuel injector, and a spring is installed in the spring installation hole. It is characterized in that
[0006] a base plane and two middle support blocks protruding from the base plane are provided at the bottom of the pressing block. The two middle support blocks are symmetrically arranged along the connection line of the centers of the two fastening stud installation holes. There is a distance L 1 between the base plane of the pressing block and the thrust surface of the fuel injector. The bottom surface of the middle support block is attached to the thrust surface of the fuel injector, and the bottom surface of the middle support block is the bearing surface of the pressing block.
[0007] Preferably, an injector leakage oil return ring groove and an oil return hole are formed in the injector. The injector leakage oil return ring groove is close to the upper port of the spring installation hole, and the oil return hole communicates with the injector leakage oil return ring groove.
[0008] Preferably, the oil return hole includes a first oil return hole parallel to the axis of the injector and a second oil return hole perpendicular to and communicating with the first oil return hole. The first oil return hole communicates with the injector leakage oil return ring groove.
[0009] Preferably, a cylinder head annular oil return groove is formed in the cylinder head, and the second oil return hole is connected to the cylinder head annular oil return groove.
[0010] Preferably, an injector connecting pipe is fixedly connected to the injector. A cylinder head oil return hole and an injector connecting pipe installation hole for installing the injector connecting pipe are formed in the cylinder head. A clearance between the injector connecting pipe installation hole and the injector connecting pipe forms an oil return cavity, and the cylinder head oil return hole is communicated with the oil return cavity.
[0011] Preferably, 1mm ≤ L 1 ≤ 1.5mm.
[0012] Preferably, a start injection pressure adjusting screw is arranged at the top of the injector, and a sealing ring is installed between the lower part of the start injection pressure adjusting screw and the injector installation hole.
[0013] Preferably, the pressing block includes a connecting ear, and the fastening stud installation hole is formed at the connecting ear. Let the height of the connecting ear be L 2 , let the diameter of the fastening stud be M X , 1.5M X ≤ L 2 ≤ 2M X .
[0014] Preferably, a support fixed-distance sleeve is sleeved outside the fastening stud. The support fixed-distance sleeve is located above the pressing block. Let the height of the support fixed-distance sleeve be L 3 , 3.5M X ≤ L 3 ≤ 4.5M X .
[0015] Preferably, the tightening force of the fastening stud is 0.7 times the yield strength.
[0016] After adopting the above technical solution, the beneficial effects of the present utility model are:
[0017] The fixed pressing device for the fuel injector of the present utility model has only the bottom surface of the middle support block in contact with the thrust surface of the fuel injector, and the base plane is suspended above the thrust surface of the fuel injector. That is, the bearing surface of the pressing block of the present utility model has a smaller area compared to the bearing surface of the pressing block in the prior art, increasing the contact surface pressure. Moreover, the middle support block is far from the fastening stud, achieving small deflection and small deformation, while obtaining a larger and uniform contact surface pressure, preventing the bottom surface of the middle support block from creeping relative to the thrust surface of the fuel injector, resulting in the loosening and failure of the fastening stud. And the two fastening studs are preferably symmetrically arranged relative to the center of the central hole of the pressing block, enabling the two fastening studs to be evenly stressed.
[0018] In the fuel injector of the present utility model, there are a fuel injector leakage oil return ring groove and an oil return hole. The fuel injector leakage oil return ring groove is near the upper port of the spring installation hole, and the oil return hole communicates with the fuel injector leakage oil return ring groove. Placing the fuel injector leakage oil return ring groove in an upper position, close to the upper port of the spring installation hole, can make the oil return flow through the entire spring, achieving sufficient cooling of the spring by the oil return and preventing the spring from overheating and suffering fatigue fracture.
[0019] In summary, the fixed pressing device for the fuel injector of the present utility model can prevent the bearing surface of the pressing block from creeping and separating from the fuel injector installation surface, avoid the loosening and failure of the stud, and prevent the spring from overheating and suffering fatigue fracture. Description of the Drawings
[0020] Figure 1 is a schematic structural diagram of a fixed pressing device for a fuel injector in the prior art;
[0021] Figure 2 is a schematic structural diagram of the fixed pressing device for the fuel injector of the present utility model;
[0022] Figure 3 is Figure 2 a cross-sectional view taken along line A-A in
[0023] Figure 4 is Figure 2 a view in the direction of B in
[0024] Figure 5 is a schematic cross-sectional view of the pressing block;
[0025] Figure 6 is Figure 5 a top view of
[0026] Figure 7 is Figure 2 a cross-sectional view taken along line C-C in
[0027] Figure 1 In the figures: 1, cylinder head; 102, spring installation hole; 2, pressing block; 3, fastening stud; 4, fuel injector; 400, fuel injector leakage oil return hole; 401, spring; S, bearing surface of the pressing block.
[0028] Figures 2 to 7 Among them: 1. Cylinder head; 101. Injector mounting hole; 102. Spring mounting hole; 103. Oil return cavity; 104. Cylinder head annular oil return groove; 105. Cylinder head oil return hole; 2. Pressure block; 3. Fastening stud; 201. Pressure block center hole; 202. Fastening stud mounting hole; 203. Base plane; 204. Middle support block; 205. Connecting ear; 4. Injector; 401. Spring; 402. Thrust surface of injector; 403. Injector leakage oil return ring groove; 404. Oil return hole; 4041. First oil return hole; 4042. Second oil return hole; 405. Injector nozzle; 406. Start injection pressure adjustment screw; 407. Sealing ring; 408. Injector nozzle; 45. Bushing; S. Pressure block bearing surface. Specific embodiments
[0029] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and efficacy of the present invention, but it is not intended to limit the protection scope of the appended claims of the present invention.
[0030] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0031] In addition, although terms such as first, second, and third can be used in the text to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms can only be used to distinguish one element, component, region, layer, or segment from another region, layer, or segment. Unless the context clearly indicates otherwise, terms such as "first" and "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer, or segment discussed below can be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.
[0032] The embodiments of the present invention disclose as Figures 2 to 4The shown fuel injector fixing and pressing device includes a cylinder head 1, a pressing block 2, and fastening studs 3. An injector mounting hole 101 for mounting a fuel injector 4 is provided on the cylinder head 1. The pressing block 2 is provided with a pressing block center hole 201 and two fastening stud mounting holes 202. The fastening studs 3 pass through the fastening stud mounting holes 202 to fix the pressing block 2 and the fuel injector 4 on the cylinder head 1. A spring mounting hole 102 is provided on the fuel injector 4, and a spring 401 is installed in the spring mounting hole 102.
[0033] As Figures 4 to 6 shown, a base plane 203 and two middle support blocks 204 protruding from the base plane are provided at the bottom of the pressing block 2. The two middle support blocks 204 are symmetrically arranged along the connection line of the centers of the two fastening stud 3 mounting holes. There is a distance L between the base plane 203 of the pressing block 2 and the thrust surface 402 of the fuel injector. 1 , the bottom surface of the middle support block 204 is in contact with the thrust surface 402 of the fuel injector, and the bottom surface of the middle support block 204 is the bearing surface S of the pressing block.
[0034] In the prior art, the bottom surface of the entire pressing block is the bearing surface. In the present utility model, since only the bottom surface of the middle support block 204 is in contact with the thrust surface 402 of the fuel injector, the base plane 203 is suspended above the thrust surface 402 of the fuel injector, that is, the bearing surface S of the pressing block in the present utility model is smaller than the bearing surface area of the pressing block in the prior art, increasing the contact surface pressure. And the middle support block 204 is far from the fastening stud 3, achieving small deflection and small deformation, while obtaining a large and uniform contact surface pressure, preventing the bottom surface of the middle support block 204 from creeping relative to the thrust surface 402 of the fuel injector, resulting in the loosening and failure of the fastening stud 3. And the two fastening studs 3 are preferably symmetrically arranged relative to the center of the pressing block center hole 201, realizing uniform force on the two fastening studs 3.
[0035] The area of the bearing surface S of the pressing block should not be too large, otherwise the contact surface pressure is too small, and there will be a risk of creeping during work. At the same time, the area of the bearing surface S of the pressing block should not be too small, and it needs to be controlled below the allowable contact surface pressure of the material to prevent the bearing surface S of the pressing block from being crushed or deformed too much and failing. The contact surface pressure is obtained by dividing the pre-tightening force of the fastening stud 3 by the area of the bearing surface S of the pressing block.
[0036] As Figure 2 and Figure 3 shown, the fuel injector 4 of the present utility model is provided with a fuel injector leakage return oil ring groove 403 and a return oil hole 404. The fuel injector leakage return oil ring groove 403 is near the upper port of the spring mounting hole 102, and the return oil hole 404 communicates with the fuel injector leakage return oil ring groove 403. Placing the position of the fuel injector leakage return oil ring groove 403 upward, making it close to the upper port of the spring mounting hole 102, can enable the return oil to flow through the entire spring 401, realizing sufficient cooling of the spring 401 by the return oil and preventing the spring 401 from overheating and fatigue fracture.
[0037] AsFigure 2 As shown, it is preferred that the oil return hole 404 includes a first oil return hole 4041 parallel to the axis of the fuel injector 4 and a second oil return hole 4042 perpendicular to and communicating with the first oil return hole 4041. The first oil return hole 4041 communicates with the fuel injector leakage oil return ring groove 403. A cylinder head annular oil return groove 104 is formed on the cylinder head 1, and the second oil return hole 404 communicates with the cylinder head annular oil return groove 104.
[0038] As Figure 2 and Figure 7 shown, the fuel injector 4 is fixedly connected with a fuel injector connection pipe 405. A cylinder head oil return hole 105 and a fuel injector connection pipe installation hole for installing the fuel injector connection pipe 408 are formed on the cylinder head 1. A clearance between the fuel injector connection pipe installation hole and the fuel injector connection pipe 408 forms an oil return cavity 103, and the cylinder head oil return hole 105 communicates with the oil return cavity 103.
[0039] As Figure 2 shown, there is a distance L1 between the base plane 203 of the pressing block 2 and the thrust surface 402 of the fuel injector, and 1mm ≤ L1 ≤ 1.5mm. Ensure that the pressing block is fully suspended so that the base plane 203 will not contact the thrust surface 402 of the fuel injector when being pressed.
[0040] A start injection pressure adjusting screw 406 is arranged at the top of the fuel injector 4, and a sealing ring 407 is installed between the lower part of the start injection pressure adjusting screw 406 and the fuel injector installation hole 101. Prevent fuel from leaking out from the thread of the start injection pressure adjusting screw 406.
[0041] In some embodiments, as Figures 2 to 6 shown, the pressing block 2 includes a connecting ear 205, and the fastening stud 3 installation hole is formed at the connecting ear 205. Let the height of the connecting ear 205 be L 2 , let the diameter of the fastening stud 3 be M X , 1.5M X ≤ L 2 ≤ 2M X . A support spacing sleeve is sleeved outside the fastening stud 3, and the support spacing sleeve is located above the pressing block 2. Let the height of the support spacing sleeve be L 3 , 3.5M X ≤ L 3 ≤ 4.5M X . Generally, a longer fastening stud 3 is adopted to realize long flexible stud connection, reduce the alternating stress amplitude of the fastening stud, improve the fatigue strength of the fastening stud 3, and at the same time obtain sufficient residual pre-tightening force to ensure that the fuel injector is fully pressed and prevent seal failure.
[0042] As Figure 2As shown, the tightening force of the fastening stud 3 is 0.7 times the yield strength. A bushing is installed between the lower part of the fuel injector 4 and the cylinder head 1. The specification of the fastening stud 3 is selected according to the sealing surface pressure required for the bearing surface Z of the fuel injector and the bushing 5. The sealing surface pressure is 6 to 8 times the explosion pressure, and the pressing force is 1.5 to 2 times the cross-sectional area S at the lower end of the fuel injector. d The acting force multiplied by the maximum explosion pressure.
[0043] In summary, the fuel injector fixing and pressing device of the present utility model can prevent the bearing surface of the pressing block from creeping and separating from the fuel injector installation surface, avoid the loosening and failure of the stud, and can realize sufficient oil return to cool the spring, thus avoiding the overheating and fatigue fracture of the spring.
[0044] The present utility model is not limited to the above embodiments. All improvements made based on the concept, principle, structure and method of the present utility model are within the protection scope of the present utility model.
Claims
1. A fuel injector fixing and clamping device, comprising a cylinder head, a pressure block and a fastening stud, wherein the cylinder head is provided with a fuel injector mounting hole for mounting the fuel injector, the pressure block is provided with a pressure block center hole and two fastening stud mounting holes, the fastening stud passes through the fastening stud mounting holes to fix the pressure block and the fuel injector on the cylinder head, the fuel injector is provided with a spring mounting hole, a spring is installed in the spring mounting hole, and the invention is characterized in that: The bottom of the pressure block is provided with a base plane and two middle support blocks protruding from the base plane, the two middle support blocks are symmetrically arranged along the line connecting the centers of the two fastening stud mounting holes, there is a distance L1 between the base plane of the pressure block and the thrust surface of the injector, the bottom surface of the middle support block is in contact with the thrust surface of the injector, and the bottom surface of the middle support block is the pressure bearing surface of the pressure block.
2. The fuel injector fixing and clamping device according to claim 1, characterized in that: The injector is provided with an injector leakage oil return ring groove and an oil return hole. The injector leakage oil return ring groove is close to the upper end of the spring mounting hole, and the oil return hole is communicated with the injector leakage oil return ring groove.
3. The fuel injector fixing and clamping device according to claim 2, characterized in that: The oil return hole comprises a first oil return hole parallel to the axis of the fuel injector and a second oil return hole perpendicular to and communicating with the first oil return hole, wherein the first oil return hole is communicated with the leakage oil return ring groove of the fuel injector.
4. The fuel injector fixing and clamping device according to claim 3, characterized in that: The cylinder head is provided with an annular oil return groove, and the second oil return hole is communicated with the annular oil return groove.
5. The fuel injector fixing and clamping device according to claim 1, characterized in that: The injector is fixedly connected to an injector pipe, the cylinder head is provided with a cylinder head oil return hole and an injector pipe mounting hole for mounting the injector pipe, the gap between the injector pipe mounting hole and the injector pipe forms an oil return chamber, and the cylinder head oil return hole is connected to the oil return chamber.
6. The fuel injector fixing and clamping device according to claim 1, characterized in that: 1mm≤L1≤1.5mm.
7. The fuel injector fixing and clamping device according to claim 1, characterized in that: A start-up pressure adjustment screw is arranged on the top of the fuel injector, and a sealing ring is installed between the lower part of the start-up pressure adjustment screw and the fuel injector mounting hole.
8. The fuel injector fixing and clamping device according to claim 1, characterized in that: The pressing block includes a connecting ear, and the fastening stud mounting hole is opened at the connecting ear. Assuming the height of the connecting ear is L2, and the diameter of the fastening stud is M X , 1.5M X ≤L2≤2M X .
9. The fuel injector fixing and clamping device according to claim 1, characterized in that: The fastening stud outer sleeve is provided with a support distance sleeve, and the support distance sleeve is located above the pressing block. The height of the support distance sleeve is L3, 3.5M X ≤L3≤4.5M X .
10. The fuel injector fixing and clamping device according to claim 1, characterized in that: The tightening force of the fastening stud is 0.7 times the yield strength.