Dismounting device and method for main pin bush on front drive axle

Abstract

The invention relates to a device and method for disassembling a main pin bush on a front drive axle, and relates to the technical field of upper main pin bush disassembling. The front end of a loading rod of the device faces the front drive axle and is provided with an expansion core, the periphery of the expansion core is sleeved with an expansion sleeve, and a torsion nut, the expansion core and the expansion sleeve are all arranged in the upper main pin bush; the expansion sleeve is provided with a plurality of claw strip blocks which are annularly arranged, the claw strip blocks are clamped and hooked with the step surface of the upper main pin bushing, and the torsion nut is arranged at the front end of the loading rod and used for adjusting the relative position of the expansion core and the expansion sleeve; the rear end of the loading rod is connected with a fixed handle in a fastening mode, and the periphery of the loading rod is sleeved with an inertia hammering sleeve in a sliding mode. By means of the method, efficient and lossless disassembly of the upper kingpin bush is achieved, scratching of the inner wall of a bush hole in a traditional method is avoided, the hidden danger of leakage of lubricating oil is fundamentally eradicated, and therefore the integrity of parts is guaranteed, the maintenance cost is remarkably reduced, and the overall service life of a steering system is prolonged.

Description

Technical Field

[0001] This invention relates to the field of upper kingpin bushing disassembly technology, and specifically discloses a device and method for disassembling the upper kingpin bushing of a front drive axle. Background Technology

[0002] The steering system, a key component ensuring vehicle safety, consists of a front axle assembly and a steering knuckle. The front axle is connected to the frame crossbeams at both ends via kingpins. The steering knuckle is mounted on the kingpin and can rotate around its axis, allowing for wheel direction adjustment with the help of the power steering mechanism. To prevent deformation of the steering knuckle thrust bearing and kingpin due to frictional heat, copper bushings are installed in both the upper and lower kingpin holes as intermediate buffer layers. These bushings have a high-precision interference fit with their holes, resulting in an extremely tight fit that is difficult to disassemble using ordinary fitter's tools.

[0003] The invention patent with authorization announcement number CN112123273B discloses an integrated pull-out device applicable to the outer and inner rings of bearings. This device includes a coaxial outer ring expansion sleeve and an inner ring pull claw. The upper end of the outer ring expansion sleeve is connected to the inside of a pull-out base. An inner expansion mandrel is screwed onto the base and inserted into the outer ring expansion sleeve. The inner expansion mandrel has a three-stage stepped through-hole. The support ring of the inner ring pull claw is inserted into the middle hole, and the claw can extend through the through-hole. The lower end of the claw's pull arm can swing, and the pull plate has a guiding conical surface. The outer ring expansion sleeve has a large-diameter, tapered, and small-diameter sleeve. The small-diameter sleeve has a toothed ring and an open groove. The lower conical end of the inner expansion mandrel presses into the inside of the tapered sleeve. The pull-out base has stepped through-holes and can mate with the outer ring expansion sleeve.

[0004] In the aforementioned disclosed patented technologies, two pulling methods can be used to disassemble the upper kingpin bushing. Both methods require external force-assisted equipment such as a hydraulic puller. When a certain torque is reached, the gap between the bushing and the kingpin widens, allowing for gradual peeling. This operation easily causes mechanical damage to the inner wall of the upper kingpin bushing hole, increasing maintenance costs and shortening the component's lifespan. Therefore, developing an efficient and safe bushing disassembly device has become a key technological breakthrough for improving disassembly efficiency, protecting the inner wall of the bushing hole from damage, and reducing maintenance costs. Summary of the Invention

[0005] To address the issues of high maintenance costs and reduced lifespan in the current process of removing upper kingpin bushings, this invention provides a device and method for removing upper kingpin bushings on a front-drive axle.

[0006] To address the above problems, the present invention provides the following technical solution: A kingpin bushing removal device for a front-drive axle includes a loading rod. The front end of the loading rod faces the front-drive axle and is fitted with an expansion mandrel. An expansion sleeve and a torque nut are fitted around the expansion mandrel. Both the expansion mandrel and the expansion sleeve are arranged inside the upper kingpin bushing. The expansion sleeve is provided with multiple annularly arranged claw strips, which are locked and connected to the stepped surface of the upper kingpin bushing. The torque nut is arranged at the front end of the loading rod and is used to adjust the relative position of the expansion mandrel and the expansion sleeve. A fixed handle is fastened to the rear end of the loading rod. An inertial hammer sleeve is slidably fitted around the outer edge of the loading rod. The inertial hammer sleeve is used to achieve axial impact and transmit dynamic pull-out force.

[0007] Preferably, the front end of the loading rod is provided with a protruding head, the protruding head has an opening cavity inside, the front and rear ends of the expansion core are respectively provided with a sleeve head and a screw part, the sleeve head is arranged inside the expansion sleeve, the hook claw blocks are distributed in a ring around the sleeve head, the torque nut is installed around the screw part, and the rear end of the screw part is arranged inside the opening cavity.

[0008] Preferably, the rear end of the expansion sleeve is provided with an annular portion, which is fitted around the outer periphery of the screw portion, and the sleeve head has a frustoconical structure.

[0009] Preferably, the outer diameter of the protrusion is larger than the outer diameter of the torque nut.

[0010] Preferably, the torque nut is a self-locking nut, and the inner wall of the torque nut is provided with anti-slip teeth, which are assembled with the loading rod to form a torque locking structure.

[0011] Preferably, the outer wall of the hook block is provided with a plurality of evenly distributed serrated grooves, the openings of which all face the loading rod side; the front end of the hook block is provided with a trapezoidal protrusion.

[0012] Preferably, the inertial hammer sleeve and the loading rod are fitted together with a clearance and a sliding fit.

[0013] Preferably, the fixed handle is provided with a hammering part facing the front end of the inertial hammering sleeve, and the outer diameter of the hammering part is larger than the outer diameter of the rear end of the fixed handle and smaller than the outer diameter of the inertial hammering sleeve.

[0014] Preferably, the angle between the centerline of the loading rod and the centerline of the front drive axle is 70°-80°.

[0015] On the other hand, the present invention also provides a method for removing the kingpin bushing on a front-drive axle, the method comprising: S1: Insert the combination of the expansion sleeve and the expansion core into the interior of the upper main pin bushing, so that the loading rod is arranged horizontally and the serrated groove of the hook block is locked and connected with the stepped surface of the upper main pin bushing. S2: Tighten the torque nut to drive the expansion core to move radially along the center line of the loading rod, and under the clamping and hooking action of the hook block, the upper kingpin bushing slowly disengages from the front drive axle; S3: When the upper kingpin bushing is about to come off the front drive axle, hold the inertia hammer sleeve and let the inertia hammer sleeve slide radially along the outer periphery of the loading rod, so that the inertia hammer sleeve continuously impacts the fixed handle, and simultaneously rotate the fixed handle for radial fine adjustment, so that the upper kingpin bushing completely comes off the front drive axle.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. In the pre-tightening stage, the operator only needs to use a regular wrench to tighten the torque nut. The conical expansion core moves forward through the threaded transmission, evenly spreading the hook claws with serrated grooves around the periphery, so that they are firmly engaged with the stepped surface of the inner end of the upper kingpin bushing, and generating a continuous initial pulling force. When the bushing is pulled out most of the time and the residual friction increases, it enters a more efficient inertial impact stage, allowing the operator to slide the inertial hammer sleeve and repeatedly strike the hammer part at the front end of the fixed handle, converting momentum into an instantaneous powerful impact. The above operation mode avoids the inefficiency caused by the excessively long lever arm and poor centering of single hydraulic pulling, and realizes the disassembly of the upper kingpin bushing quickly and effortlessly in a narrow space. 2. This invention features a special trapezoidal protrusion at the front end of the hook block. Its contact with the inner wall of the upper master pin bushing is not a large-area grip, but rather a precise engagement and hooking of the pre-set stepped edge at the bushing end via a serrated groove. This hooking method concentrates the pulling force entirely on the stepped structure of the upper master pin bushing itself, strictly limiting the force transmission path and thus avoiding direct friction and compression between the tool and the precision inner wall of the upper master pin bushing hole. Therefore, it eliminates the problem of hole wall scratches caused by disassembly tools, protects the geometric accuracy of the seat hole, and eliminates the safety hazard of lubricating oil leakage caused by disassembly damage. 3. The overall structure of the present invention is compact and the operation logic is simple, requiring only three steps: assembly, pre-tightening, and impact. This reduces the dependence on operator experience and large external equipment, reduces the risk of accidental damage caused by improper operation, and allows the components to undergo multiple standardized disassembly and assembly without performance degradation. From the perspective of maintenance, this significantly extends the service life of the core components. Attached Figure Description

[0017] To more clearly illustrate the technical solution of the present invention, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the overall structure of the disassembly device of the present invention assembled with the front drive axle; Figure 2 This is a cross-sectional view of the disassembly device of the present invention being assembled with the front drive axle. Figure 3 This is a schematic diagram of the overall structure of the disassembly device of the present invention; Figure 4 This is an exploded structural diagram of the disassembly device of the present invention; Figure 5 This is a schematic diagram of the inertial hammer impact sleeve mounting structure of the present invention; Figure 6 This is a schematic diagram of the expansion sleeve structure of the present invention; Figure 7 This is a schematic diagram of the expansion core structure of the present invention; In the diagram: 1. Loading rod, 2. Front drive axle, 3. Expansion core, 4. Expansion sleeve, 5. Torque nut, 6. Upper kingpin bushing, 7. Claw bar, 8. Fixed handle, 9. Inertia hammer sleeve, 10. Protruding head, 11. Opening mouth, 12. Sleeve head, 13. Screw part, 14. Circular part, 15. Serrated groove, 16. Trapezoidal protrusion, 17. Hammering part. Detailed Implementation

[0018] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] This specific embodiment provides a device for removing the kingpin bushing on a front-drive axle, such as... Figures 1-7 As shown; it includes a loading rod 1, which is the main part of the overall disassembly device; the front end of the loading rod 1 is provided with a protruding head 10, the outer diameter of the protruding head 10 is larger than the outer diameter of the loading rod 1, and the interior of the protruding head 10 is provided with an opening 11; the front end of the loading rod 1 is equipped with an expansion core 3, and the front and rear ends of the expansion core 3 are respectively provided with a sleeve head 12 and a screw part 13, and the screw part 13 is installed in the opening 11 of the protruding head 10.

[0020] A torque nut 5 is installed on the screw section 13, so that the torque nut 5 is threaded onto the outer periphery of the screw section 13. The outer diameter of the protruding head 10 is larger than the outer diameter of the torque nut 5, thereby restricting the rotational position of the torque nut 5 on the expansion core 3. The torque nut 5 is a self-locking nut, and the inner wall of the torque nut 5 is provided with anti-slip teeth, thereby enabling the torque nut 5 and the carrier rod 1 to be assembled into a torque-locking structure through the anti-slip teeth.

[0021] The expansion core 3 is surrounded by an expansion sleeve 4, with the sleeve head 12 located inside the expansion sleeve 4. The rear end of the expansion sleeve 4 has an annular portion 14, which facilitates the passage of the expansion core 3, allowing the annular portion 14 to fit around the screw portion 13, with the sleeve head 12 positioned at the front end of the annular portion 14. The expansion sleeve 4 is provided with multiple annularly arranged hook-claw strips 7, the rear ends of which are fixedly connected to the front end of the annular portion 14. The hook-claw strips 7 are annularly distributed around the sleeve head 12, and the sleeve head 12 has a frustoconical structure, ensuring that the end with the larger outer diameter of the sleeve head 12 fits against the inner wall of the annularly distributed hook-claw strips 7.

[0022] Each hook block 7 has multiple evenly distributed serrated grooves 15 on its outer wall, with the openings of the serrated grooves 15 all facing the loading rod 1, i.e., towards the rear end of the overall disassembly device; the front end of each hook block 7 has a trapezoidal protrusion 16. Both the expansion core 3 and the expansion sleeve 4 can be arranged inside the upper kingpin bushing 6, so that the front end of the overall disassembly device faces the front drive axle 2 and is arranged inside the front drive axle 2. Figures 1-2 As shown; AA is the centerline of the loading rod 1, and BB is the centerline of the front drive axle 2, so that the angle between the centerline of the loading rod 1 and the centerline of the front drive axle 2 is controlled within the range of 70°-80°. By setting the claw strip 7 of the serrated groove 15, the claw strip 7 is locked and connected with the stepped surface of the upper kingpin bushing 6, and the connection and clamping of the expansion sleeve 4 and the upper kingpin bushing 6 are enhanced by the trapezoidal protrusion 16.

[0023] A fixed handle 8 is fastened to the rear end of the loading rod 1. An inertial hammer sleeve 9 is slidably fitted around the outer periphery of the loading rod 1, and the inertial hammer sleeve 9 is arranged at the front end of the fixed handle 8. The inertial hammer sleeve 9 is fitted with the loading rod 1 with clearance and sliding fit. A hammering part 17 is provided on the front end of the fixed handle 8 facing the inertial hammer sleeve 9. The outer diameter of the hammering part 17 is larger than the outer diameter of the rear end of the fixed handle 8 and smaller than the outer diameter of the inertial hammer sleeve 9, so that the hammering part 17 can contact the inertial hammer sleeve 9.

[0024] The foregoing has described in detail an embodiment of a kingpin bushing removal device for a front-wheel drive axle. Based on the kingpin bushing removal device for a front-wheel drive axle described in the above embodiment, this invention also provides a corresponding method for removing the kingpin bushing for a front-wheel drive axle, comprising the following steps: S1: During the assembly stage, the combination of the expansion sleeve 4 and the expansion core 3 is inserted into the interior of the upper kingpin bushing 6. The operator can arrange the loading rod 1 horizontally and make the serrated groove 15 of the hook block 7 lock and connect with the stepped surface of the upper kingpin bushing 6, thereby stably inserting the front end of the overall disassembly device into the interior of the upper kingpin bushing 6 of the front drive axle 2. S2: During the pre-tightening stage, the operator can use a manual tool to tighten the torque nut 5. The torque nut 5 can gradually drive the expansion core 3 to move radially along the center line (AA) of the loading rod 1, and under the clamping and hooking action of the hook block 7, the upper master pin bushing 6 slowly disengages from the front drive axle 2. S3: Inertial impact stage, when the upper kingpin bushing 6 is about to come off the front drive axle 2, the operator holds the inertial hammer sleeve 9 and makes the inertial hammer sleeve 9 slide radially along the outer periphery of the loading rod 1, so that the inertial hammer sleeve 9 continuously impacts the hammering part 17 of the fixed handle 8, and can simultaneously rotate the fixed handle 8 for radial fine adjustment, so that the upper kingpin bushing 6 gradually and completely comes off the front drive axle 2, so as to complete the disassembly operation of the upper kingpin bushing 6.

[0025] Compared with existing technologies, the kingpin bushing removal device for front-drive axles can effectively avoid mechanical damage to the inner wall of the upper kingpin bushing hole caused by traditional methods in practical applications, and eliminate the safety hazard of lubricating oil leakage from the upper kingpin bushing hole 6, thereby reducing maintenance costs. In summary, this device is simple to operate, easy to carry, and effective for disassembling the upper kingpin bushing 6, and has significant promotional value in the field of upper kingpin removal technology.

[0026] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A kingpin bushing removal device for a front-drive axle, comprising a mounting rod (1), characterized in that, The front end of the loading rod (1) faces the front drive axle (2) and is equipped with an expansion core (3). An expansion sleeve (4) and a torque nut (5) are fitted around the expansion core (3). The expansion core (3) and the expansion sleeve (4) are both arranged inside the upper kingpin bushing (6). The expansion sleeve (4) is provided with multiple ring-shaped hook blocks (7). The hook blocks (7) are locked and connected to the stepped surface of the upper kingpin bushing (6). The torque nut (5) is arranged at the front end of the loading rod (1) and is used to adjust the relative position of the expansion core (3) and the expansion sleeve (4). The rear end of the loading rod (1) is fastened with a fixed handle (8). An inertial hammer sleeve (9) is slidably fitted around the loading rod (1). The inertial hammer sleeve (9) is used to realize axial impact and transmit dynamic pull-out force.

2. The kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The front end of the loading rod (1) is provided with a protruding head (10), and the protruding head (10) has an opening (11) inside. The front and rear ends of the expansion core (3) are respectively provided with a sleeve head (12) and a screw part (13). The sleeve head (12) is arranged inside the expansion sleeve (4). The hook claws (7) are distributed in a ring around the sleeve head (12). The torque nut (5) is installed around the screw part (13). The rear end of the screw part (13) is arranged inside the opening (11).

3. The kingpin bushing removal device for a front-drive axle according to claim 2, characterized in that, The rear end of the expansion sleeve (4) is provided with a ring part (14), which is fitted around the screw part (13), and the sleeve head (12) is a frustoconical structure.

4. The kingpin bushing removal device for a front-drive axle according to claim 2, characterized in that, The outer diameter of the protruding head (10) is larger than the outer diameter of the torque nut (5).

5. The kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The torque nut (5) is a self-locking nut. The inner wall of the torque nut (5) is provided with anti-slip teeth. The anti-slip teeth are assembled with the mounting rod (1) to form a torque locking structure.

6. The kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The outer wall of the hook block (7) is provided with a plurality of evenly distributed serrated grooves (15), and the openings of the serrated grooves (15) are all facing the side of the loading rod (1); the front end of the hook block (7) is provided with a trapezoidal protrusion (16).

7. The kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The inertial hammer sleeve (9) is fitted with the loading rod (1) with clearance and sliding fit.

8. A kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The fixed handle (8) is provided with a hammering part (17) facing the front end of the inertial hammering sleeve (9). The outer diameter of the hammering part (17) is larger than the outer diameter of the rear end of the fixed handle (8) and smaller than the outer diameter of the inertial hammering sleeve (9).

9. A kingpin bushing removal device for a front-drive axle according to claim 1, characterized in that, The angle between the centerline of the loading rod (1) and the centerline of the front drive axle (2) is 70°-80°.

10. A method for removing a kingpin bushing on a front-drive axle, comprising the kingpin bushing removal device for a front-drive axle according to any one of claims 1-9, characterized in that, The method includes: S1: Insert the combination of expansion sleeve (4) and expansion core (3) into the interior of upper main pin bushing (6), so that the loading rod (1) is arranged horizontally and the serrated groove (15) of the hook block (7) is locked and connected with the stepped surface of the upper main pin bushing (6). S2: Tighten the torque nut (5), drive the expansion core (3) to move radially along the center line of the loading rod (1), and under the clamping and hooking action of the hook block (7), make the upper main pin bushing (6) slowly disengage from the front drive axle (2). S3: When the upper kingpin bushing (6) is about to come off the front drive axle (2), hold the inertial hammer sleeve (9) and make the inertial hammer sleeve (9) slide radially along the outer periphery of the loading rod (1), so that the inertial hammer sleeve (9) continuously impacts the fixed handle (8), and simultaneously rotate the fixed handle (8) for radial fine adjustment, so that the upper kingpin bushing (6) completely comes off the front drive axle (2).

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