A sliding bearing press-fitting aid for fuel pump

Abstract

The utility model discloses a kind of sliding bearing press-fit aids for fuel pump, including hollow base;Sliding mandrel, it is axially slidably installed in the base, upper end protrudes the upper end surface of base and is equipped with guide mandrel;Edge cutting pin, vertically set in the upper end surface of base;Press head, sleeve set on the guide mandrel, with sliding bearing mounting portion and press-fit portion, the sliding bearing mounting portion is equipped with the plunger spring of radial installation, the end of this plunger spring is equipped with the locating steel ball that can elastically expand and contract, for forming locating cooperation with the oil inlet hole of sliding bearing;Spring seat, fixedly connected in the lower end of the base;Compression spring, lower end abuts on spring seat, upper end abuts the sliding mandrel;Among them, the coaxial cooperation of guide mandrel and press head press-fit portion, the plug-in cooperation of locating steel ball and oil inlet hole jointly constitute double locating structure in press-fit process.The reliability, scrap rate and efficiency problem of traditional manual assembly are solved.

Description

Technical Field

[0001] This utility model belongs to the field of fuel pump manufacturing technology, and in particular relates to a sliding bearing press-fitting auxiliary tool for fuel pumps. Background Technology

[0002] In the bearing assembly structure of a mechanical fuel pump camshaft, bearing housings with sliding bearings are installed at both ends of the camshaft to provide positioning and support. To ensure lubrication, both the bearing housing and the sliding bearing have radial through holes. During assembly, the two holes must be strictly aligned so that lubricating oil can enter the bearing through this channel, reducing frictional loss between the camshaft journal and the sliding bearing, thereby extending service life. The traditional assembly method is as follows: the operator places the sliding bearing in the bearing housing hole, manually adjusts the lubricating oil hole of the sliding bearing to the same vertical plane as the lubricating oil hole of the bearing housing, and then inserts the pressure head into the inner hole of the sliding bearing, using a press to press it into place. However, this method has significant drawbacks: poor positioning reliability: the alignment of the lubricating oil hole relies entirely on the operator's visual judgment and manual adjustment, which is prone to misalignment due to visual errors, operator fatigue, or lack of experience; high scrap rate: when the outer wall of the sliding bearing completely covers the lubricating oil hole of the bearing housing, the lubrication channel is blocked, and the assembly becomes scrap due to lack of lubrication; low efficiency: the repeated manual calibration and rework process prolongs the assembly cycle and restricts the efficiency of mass production. Therefore, there is an urgent need for a press-fitting tool that can automatically position sliding bearings and bearing housings mechanically to eliminate human interference, ensure accurate alignment of oil holes, and improve assembly quality and efficiency. Summary of the Invention

[0003] To address the problems existing in the prior art, this utility model provides a fuel pump sliding bearing press-fitting auxiliary tool that ensures precise alignment of the oil hole and improves assembly quality and efficiency.

[0004] This utility model is implemented as follows: a fuel pump sliding bearing press-fitting auxiliary tool, characterized by comprising: a hollow base; a sliding mandrel, axially slidably mounted within the base, with its upper end extending beyond the upper surface of the base and equipped with a guide mandrel; a chamfered pin, vertically disposed on the upper surface of the base, used for circumferential positioning of the sliding bearing seat; a press head, sleeved on the guide mandrel, having a sliding bearing mounting part that mates with the inner hole of the sliding bearing and a press-fitting part extending to the outside of the sliding bearing, wherein a radially mounted plunger spring is provided within the sliding bearing mounting part, and the end of the plunger spring is provided with an elastically extendable positioning steel ball for forming a positioning fit with the oil inlet hole of the sliding bearing; a spring seat, fixedly connected to the lower end of the base; and a compression spring, with its lower end abutting against the spring seat and its upper end abutting against the sliding mandrel; wherein the coaxial fit between the guide mandrel and the press-fitting part, and the insertion fit between the positioning steel ball and the oil inlet hole, together constitute a double positioning structure during the press-fitting process.

[0005] A further preferred embodiment includes a sliding mandrel anti-rotation mechanism, comprising a set screw that penetrates radially through the side wall of the base and an axial guide groove formed on the outer wall of the sliding mandrel, wherein the inner end of the set screw extends into the guide groove to form a circumferential limiting fit.

[0006] More preferably, the lower part of the base is provided with an exhaust hole in the radial direction.

[0007] More preferably, the lower end of the sliding mandrel is provided with a mounting hole, and the upper end of the compression spring is installed in the mounting hole.

[0008] More preferably, a locating pin is provided on the upper end face of the sliding mandrel on the opposite side of the plunger spring, and a locating groove that is clearance-fitted with the locating pin is provided on the lower end face of the sliding bearing mounting part in the radial direction.

[0009] In a further preferred embodiment, the lower end face of the sliding bearing mounting portion corresponding to the plunger spring position is provided with a fixing hole, and a set screw for locking the plunger spring is installed in the fixing hole.

[0010] Technical effects and advantages of this utility model: This utility model provides a sliding bearing press-fitting auxiliary tool for a fuel pump. Its core structure includes: an axial positioning component: a hollow base cooperates with an axially sliding sliding mandrel, the sliding mandrel is used to support the bearing seat and realize the axial positioning of the bearing seat; a circumferential positioning component: a vertically set chamfered pin limits the circumferential position of the bearing seat and restricts its rotational freedom; a dual positioning press head: the press head achieves coaxial cooperation through a guide mandrel (first positioning), and its internal plunger spring drives the positioning steel ball to extend radially and form an insertion cooperation with the oil inlet hole of the sliding bearing (second positioning); technical effects and problem solving: It solves the positioning reliability problem. Traditional manual visual alignment has visual errors and operational uncertainties. This utility model ensures axial position accuracy through mechanical coaxial positioning (cooperation between the guide mandrel and the press-fitting part); radial positioning of the steel ball (insertion of the positioning steel ball into the oil inlet hole) realizes automatic radial position calibration; the dual positioning structure eliminates human operation interference and improves the oil hole alignment accuracy from manual experience dependence to mechanical cooperation level. Traditional methods for reducing scrap rates suffer from lubrication channel blockage due to misaligned oil holes. This invention addresses this by using a forced insertion and engagement of steel balls with the oil inlet hole; circumferential positioning prevents bearing housing rotational misalignment, thus physically avoiding the risk of oil hole blockage. It also improves assembly efficiency: traditional manual calibration requires repeated adjustments. In summary, this invention automates the entire "placement-positioning-pressing" process; dual positioning reduces rework, significantly improving batch assembly efficiency. This auxiliary tool, through its innovative mechanical dual positioning, systematically solves the reliability, scrap rate, and efficiency problems of traditional manual assembly, providing an industrial solution for precision bearing assembly. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the structure of this utility model;

[0012] Figure 2 This is a utility model Figure 1 Sectional view of AA.

[0013] In the diagram: 1. Hollow base; 2. Sliding mandrel; 21. Mounting hole; 3. Guide mandrel; 4. Chamfered pin; 5. Press head; 51. Sliding bearing mounting part; 52. Press fitting part; 53. Positioning groove; 54. Fixing hole; 6. Piston spring; 7. Positioning steel ball; 8. Spring seat; 81. Compression spring; 9. Sliding mandrel anti-rotation mechanism; 91. Set screw; 92. Axial guide groove; 10. Positioning pin; 11. Vent hole; 12. Set screw; 13. Sliding bearing; 131. Oil inlet hole; 14. Sliding bearing seat; 141. Oil inlet hole. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0015] Please see Figures 1 to 2 A fuel pump sliding bearing press-fitting fixture includes: a hollow base 1; a sliding mandrel 2, axially slidably mounted inside the base, with its upper end extending out of the upper end face of the base and having a guide mandrel 3; a chamfered pin 4, vertically disposed on the upper end face of the base, used for circumferential positioning of the sliding bearing seat; a press head 5, sleeved on the guide mandrel, having a sliding bearing mounting part 51 that mates with the inner hole of the sliding bearing and a press-fitting part 52 extending to the outside of the sliding bearing, wherein a radially mounted plunger spring 6 is provided in the sliding bearing mounting part, and the end of the plunger spring has an elastically extendable positioning steel ball 7, used to form a positioning fit with the oil inlet hole 131 of the sliding bearing 13; a spring seat 8, fixedly connected to the lower end of the press head; and a compression spring 81, with its lower end abutting against the spring seat and its upper end abutting against the sliding mandrel; wherein the coaxial fit between the guide mandrel and the press-fitting part, and the insertion fit between the positioning steel ball and the oil inlet hole together constitute a double positioning structure during the press-fitting process.

[0016] The hollow base of the fuel pump's sliding bearing press-fit fixture, coupled with an axially sliding mandrel, provides a stable foundation and flexible moving parts for the press-fit operation. Vertically positioned chamfered pins circumferentially position the sliding bearing housing, ensuring accurate press-fit positioning. The press head is fitted onto the guide mandrel, with its sliding bearing mounting portion mates with the inner bore of the sliding bearing. Furthermore, the internal plunger spring and positioning steel balls form a positioning engagement with the sliding bearing's oil inlet, achieving precise positioning. This dual positioning structure, with the guide mandrel and press-fit portion coaxial and the positioning steel balls inserted into the oil inlet, further improves press-fit accuracy and stability, ensuring the quality of the sliding bearing press-fit and enhancing the overall performance and reliability of the fuel pump.

[0017] A further preferred embodiment includes a sliding mandrel anti-rotation mechanism 9, comprising a set screw 91 extending radially through the sidewall of the base and an axial guide groove 92 formed on the outer wall of the sliding mandrel. The inner end of the set screw extends into the guide groove to form a circumferential limiting fit. The anti-rotation mechanism, through the circumferential limiting effect of the set screw and the guide groove, effectively prevents the sliding mandrel from rotating under lateral force during press-fitting, ensuring the coaxial accuracy of the press head and bearing, improving assembly stability, simplifying operation, and enhancing equipment durability and press-fitting efficiency.

[0018] Preferably, the lower part of the base is provided with an exhaust hole 11 in the radial direction. This can effectively expel air from the cylinder when the sliding mandrel moves up and down, reducing air resistance. This avoids the formation of air pressure that hinders the movement of the mandrel, making the mandrel move more smoothly, reducing problems such as movement jamming or uneven resistance caused by air pressure, and thus improving the smoothness, stability and efficiency of the press-fitting fixture operation.

[0019] Preferably, the lower end of the sliding mandrel is provided with a mounting hole 21, and the upper end of the compression spring 9 is installed in the mounting hole. Installing the upper end of the compression spring in the mounting hole at the lower end of the sliding mandrel provides stable support and positioning for the spring; furthermore, this installation method facilitates the assembly and disassembly of the compression spring, making subsequent maintenance and replacement convenient.

[0020] Preferably, a locating pin 10 is located on the upper end face of the sliding mandrel opposite to the plunger spring, and a locating groove 53 with clearance fit is provided radially on the lower end face of the sliding bearing mounting portion. This provides precise radial positioning for the sliding mandrel and the pressure head, effectively preventing radial displacement of the pressure head during press-fitting. Simultaneously, the clearance fit compensates for manufacturing errors, ensuring smooth assembly. This improves press-fitting accuracy and stability, reduces bearing damage caused by misalignment, and enhances assembly quality and efficiency.

[0021] Preferably, the lower end face of the sliding bearing mounting portion corresponding to the plunger spring position is provided with a fixing hole 54, and a set screw 12 for locking the plunger spring is installed in the fixing hole. Providing a fixing hole and installing a set screw on the lower end face of the sliding bearing mounting portion to lock the plunger spring prevents displacement or loosening of the plunger spring during operation, ensuring that the positioning steel ball can always accurately eject and mate with the oil inlet hole, guaranteeing accurate oil hole positioning. At the same time, the set screw is easy to disassemble, facilitating maintenance or replacement of the plunger spring, improving the reliability and service life of the auxiliary fixture.

[0022] During operation, the bearing housing 14 is fitted onto the sliding mandrel 2, and the beveled pin 4 is fitted into the hole on the flange of the bearing housing 14, with the bottom surface of the bearing housing 14 resting on the upper end face of the base. The sliding bearing mounting part of the press head 5 is inserted into the sliding bearing 13. Then, holding the sliding bearing 13 with the left hand, the press head 5 is rotated with the right hand, causing the steel ball on the plunger spring 6 to spring into the oil inlet hole 131 on the sliding bearing 13. Then, the central hole of the press head 5 is inserted into the guide mandrel of the sliding mandrel, while the locating pin 10 is inserted into the locating groove 53 of the press head. The press is started, and the sliding bearing is pressed into place, ensuring that the oil inlet hole 131 of the sliding bearing 13 is aligned with the oil inlet hole 141 of the bearing housing 14. When the press rod of the press is lifted, the sliding mandrel 2 also rises and resets under the spring force of the spring 81, and the pressed bearing housing can be removed.

[0023] In summary, this fuel pump sliding bearing press-fitting fixture achieves efficient and precise press-fitting through the collaborative work of multiple components. The hollow base and the axially sliding mandrel form the basic frame, while the chamfered pin achieves circumferential positioning. The press head, in conjunction with the guide mandrel and internal plunger spring and positioning steel balls, completes radial positioning. This dual positioning structure ensures press-fitting accuracy. Furthermore, optimized designs for the sliding mandrel anti-rotation mechanism, vent, mounting holes, positioning pins and slots, fixing holes and set screws further enhance the fixture's stability, smoothness, maintainability, and positioning accuracy.

[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sliding bearing press-fitting fixture for a fuel pump, characterized in that, include: Hollow base; sliding mandrel, which can be axially slidably installed in the base, with its upper end extending out of the upper end face of the base and provided with a guide mandrel; A chamfered pin is vertically positioned on the upper surface of the base and is used for circumferential positioning of the sliding bearing seat. The pressure head, sleeved on the guide mandrel, has a sliding bearing mounting part that mates with the inner hole of the sliding bearing and a press-fit part that extends to the outside of the sliding bearing. The sliding bearing mounting part is provided with a radially mounted plunger spring. The end of the plunger spring is provided with a positioning steel ball that can be elastically extended and retracted, which is used to form a positioning fit with the oil inlet of the sliding bearing. A spring seat is fixedly connected to the lower end of the base; The compression spring has its lower end abutting against the spring seat and its upper end abutting against the sliding spindle; The coaxial fit between the guide mandrel and the press-fitting part, and the insertion fit between the positioning steel ball and the oil inlet hole together constitute a dual positioning structure during the press-fitting process.

2. The fuel pump sliding bearing press-fitting fixture according to claim 1, characterized in that: It also includes a sliding mandrel anti-rotation mechanism, which includes a set screw that penetrates the side wall of the base radially and an axial guide groove formed on the outer wall of the sliding mandrel. The inner end of the set screw extends into the guide groove to form a circumferential limiting fit.

3. The fuel pump sliding bearing press-fitting fixture according to claim 1, characterized in that: The lower part of the base is provided with an exhaust hole in the radial direction.

4. The fuel pump sliding bearing press-fitting fixture according to claim 1, characterized in that: The lower end of the sliding mandrel is provided with a mounting hole, and the upper end of the compression spring is installed in the mounting hole.

5. The fuel pump sliding bearing press-fitting fixture according to claim 1, characterized in that: A locating pin is provided on the upper end face of the sliding mandrel on the opposite side of the plunger spring, and a locating groove that is clearance-fitted with the locating pin is provided on the lower end face of the sliding bearing mounting part in the radial direction.

6. The fuel pump sliding bearing press-fitting fixture according to claim 1, characterized in that: A fixing hole is provided on the lower end face of the sliding bearing mounting part corresponding to the position of the plunger spring, and a set screw for locking the plunger spring is installed in the fixing hole.

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