An auxiliary dismounting device for a cylinder liner

Abstract

This invention relates to the field of machining and assembly technology, and discloses an auxiliary disassembly device for cylinder liners. The device includes a mandrel with a tapered end, which is fitted inside a radially expandable elastic spring. At least one O-ring is fitted around the outer periphery of the elastic spring. A drive component is connected to the upper end of the mandrel, and an anti-rotation guide component is fitted in the middle of the mandrel. The mandrel is inserted into the cylinder liner of the cylinder block. Rotating the drive component clockwise drives the mandrel to move linearly axially. The engagement between the outer tapered surface of the tapered head and the inner tapered surface of the elastic spring forces the elastic spring to expand radially, pressing the O-ring against the inner wall of the cylinder liner. Pulling the drive component upwards moves the cylinder liner upwards with the mandrel, thereby removing it from the cylinder block. This invention, through the tapered mandrel and elastic spring structure, combines the lifting force with the radial expansion force, utilizing the controllable static friction generated between the O-ring and the inner wall of the cylinder liner to achieve non-destructive disassembly of the cylinder liner.

Description

Technical Field

[0001] This invention relates to the field of machining and assembly technology, and specifically to an auxiliary disassembly device for cylinder liners. Background Technology

[0002] In the field of machining and assembly, cylinder liners, as core components of internal combustion engines and other equipment, are typically installed in the cylinder bore of the cylinder block with a small clearance fit for easy disassembly. To ensure sealing performance, multiple O-rings are often fitted between the outer wall of the cylinder liner and the inner bore of the cylinder. Currently, conventional methods for disassembling this type of assembly often involve using mechanical pull tools, which apply axial pulling force directly to the end face of the cylinder liner using pull claws; or using hydraulic methods, injecting high-pressure oil into the fit clearance between the cylinder liner and the cylinder block to assist in disassembly using hydraulic pressure.

[0003] However, due to the elasticity of the O-ring and its tight fit against the inner wall of the cylinder bore, the initial static friction between the cylinder liner and the cylinder block is relatively high. In practice, the aforementioned mechanical pulling tools often fail to directly and effectively transfer force to the cylinder liner, and forced pulling can easily cause the pull claws to slip off or damage the cylinder liner end face. Furthermore, because the outer wall of the cylinder liner is smooth and lacks an effective point of force application, conventional hooking methods cannot be used, making the disassembly process extremely difficult, sometimes even requiring destructive removal of the cylinder liner. This is not only inefficient but also easily scratches the inner bore surface of the cylinder block, affecting its reusability.

[0004] Therefore, this application provides a simple, reliable auxiliary disassembly device that does not damage the cylinder liner and cylinder block, while avoiding damage to the cylinder liner and cylinder block. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the purpose of this invention is to provide an auxiliary disassembly device for cylinder liners, which solves the problem that the cylinder liner is difficult to remove from the cylinder block because the surrounding area is smooth and an O-ring is fitted between the cylinder liner and the cylinder block; and the removal process is difficult and easily damages the cylinder liner.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An auxiliary disassembly device for cylinder liners includes a mandrel with a tapered end, the tapered end being fitted inside a radially expandable elastic spring, the elastic spring having at least one O-ring fitted around its outer periphery; a drive member is connected to the upper end of the mandrel, and an anti-rotation guide member is fitted on the mandrel below the drive member to prevent rotation of the mandrel;

[0008] The core rod is inserted into the cylinder liner of the cylinder body. The drive unit drives the core rod to move linearly along the axial direction. The outer conical surface of the conical head and the inner conical surface of the elastic spring are used to force the elastic spring to expand radially, pressing the O-ring tightly against the inner wall of the cylinder liner. The cylinder liner is then pulled upward as the core rod moves upward, and then pulled out of the cylinder body.

[0009] Furthermore, the anti-rotation guide includes a fixed sleeve, which is sleeved on the outside of the core rod, and the end of the fixed sleeve has a guide groove extending axially; an anti-rotation pin is inserted through the core rod, and the anti-rotation pin is slidably engaged in the guide groove to restrict the core rod from rotating relative to the fixed sleeve.

[0010] Furthermore, the fixed sleeve is also equipped with a pressure handle for easy operation, which is used to prevent the fixed sleeve from rotating with the driving component.

[0011] Furthermore, the elastic spring has multiple axial through grooves circumferentially formed on its sidewalls, and each axial through groove has a stress relief hole at its starting end to ensure uniform deformation of the elastic spring when it is under force; each axial through groove has a protruding edge for fixing an O-ring at its end.

[0012] Furthermore, a threaded hole is provided at one end of the driving component, and an external thread is provided at the top of the core rod; the external thread of the core rod cooperates with the threaded hole on the driving component, and the core rod moves up and down in the threaded hole by rotating the thread.

[0013] Furthermore, six O-rings are provided to ensure that the friction generated during the lifting of the handle can drive the cylinder liner to move.

[0014] Furthermore, the outer conical surface of the core rod's conical head and the inner conical surface of the elastic spring have a matching cone angle of 20°; this causes the diameter of the elastic spring to increase by 0.35 mm for every 1 mm axial movement of the core rod, thereby compressing and deforming the O-ring.

[0015] Furthermore, the outer peripheral surface of the drive component is provided with anti-slip mesh or knurling to facilitate lifting and rotation.

[0016] Furthermore, the elastic spring is made of spring steel with a hardness of HRC45-50, ensuring that the spring can return to its initial state after the external force is removed after it has expanded.

[0017] In use, the operator inserts the small end of the device (i.e., the elastic spring and O-ring portion) into the cylinder liner of the cylinder block, so that the elastic spring protrudes from the cylinder liner opening. Holding the retaining sleeve with one hand and pressing the fingers on the clamping handle that passes laterally through the retaining sleeve, the operator rotates the handle clockwise with the other hand. Because the anti-rotation pin slides within the guide groove, restricting the rotation of the core rod, the clockwise rotation of the handle causes the core rod to move axially upward relative to the retaining sleeve and elastic spring. The outer conical surface of the core rod's tapered head presses upward against the inner conical surface of the elastic spring, forcing the multiple axial through-grooves of the elastic spring to expand radially outward. This, in turn, presses the O-ring around its outer circumference against the inner wall of the cylinder liner, generating sufficient positive pressure. The operator then lifts the core rod upward by rotating the handle, raising the entire device. The friction between the O-ring and the inner wall of the cylinder liner causes the cylinder liner to move upward until it is completely pulled out of the cylinder block. After disassembly, rotate the handle in the opposite direction to move the core rod downward. The elastic spring will automatically contract back to its initial diameter under its own elasticity, and the cylinder liner can then be removed from the device.

[0018] This invention utilizes a conical core rod and an elastic spring structure to combine upward lifting force with radial expansion force. By leveraging the controllable static friction generated between the O-ring and the inner wall of the cylinder liner, it achieves non-destructive disassembly of the cylinder liner. Compared to the direct pull-out or destructive disassembly methods in the prior art, this invention has the following significant advantages:

[0019] First, the present invention uses an O-ring as a friction medium, which utilizes its elastic deformation to make flexible contact with the inner wall of the workpiece being disassembled, completely avoiding scratches or damage that may be caused by directly clamping or prying metal parts; the user only needs to rotate the drive component to control the tightness of the O-ring, and pull it upward to remove the cylinder liner, simplifying the operation process.

[0020] Secondly, the elastic spring of this invention is made of spring steel and has undergone appropriate hardening treatment. The sidewalls are grooved and have stress relief holes, ensuring uniform deformation under stress and automatic return to the initial state after the external force is removed, meeting the needs of repeated disassembly operations. An anti-rotation guide is provided, allowing the anti-rotation pin to engage with the guide groove on the fixed sleeve, ensuring that the core rod only moves in a straight line during rotational drive and does not spin freely, resulting in efficient power transmission. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is an exploded view of the three-dimensional structure of the present invention.

[0023] Figure 2This diagram shows the assembly structure of the cylinder liner and cylinder block.

[0024] Figure 3 A cross-sectional structural diagram showing the overall structure of the present invention.

[0025] Figure 4 This is a three-dimensional structural diagram of the core rod of the present invention.

[0026] Figure 5 This is a three-dimensional structural diagram of the elastic spring of the present invention.

[0027] Figure 6 This is a schematic cross-sectional view of the elastic spring of the present invention.

[0028] Figure 7 This is a schematic cross-sectional view of the fixing sleeve of the present invention.

[0029] Figure 8 This is a schematic cross-sectional view of the drive component of the present invention.

[0030] In the diagram: 1-Core rod; 11-Conical head; 12-External threaded part; 2-Elastic spring; 21-Axial through groove; 22-Stress relief hole; 23-Raised edge; 3-O-ring; 4-Drive component; 41-Threaded hole; 5-Anti-rotation guide component; 51-Fixing sleeve; 511-Guide groove; 52-Anti-rotation pin; 6-Pressure handle; 7-Cylinder liner; 8-Cylinder body. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0033] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] In mechanical assembly, cylinder liners are often difficult to remove after being installed in the cylinder block due to their smooth surface, and traditional disassembly methods can easily damage the workpiece. This invention provides an auxiliary disassembly device for cylinder liners, which enables non-destructive and controllable disassembly of cylinder liners.

[0035] refer to Figure 1-8As shown, an auxiliary disassembly device for cylinder liners includes a mandrel 1, a drive member 4, and a radially expandable elastic spring 2. The mandrel 1 has a tapered head 11 at its end, which is fitted inside the elastic spring 2. The outer tapered surface of the mandrel 1 mates with the inner tapered surface of the elastic spring 2, and six O-rings are fitted around its outer circumference. The drive member 4 is connected to the upper end of the mandrel 1, and an anti-rotation guide member 5 is fitted in the middle to prevent rotation of the mandrel 1. The mandrel 1 is inserted into the cylinder liner 8, as... Figure 3 As shown; the clockwise rotation of the drive component 4 drives the core rod 1 to move linearly along the axial direction. The outer conical surface of the conical head 11 and the inner conical surface of the elastic spring 2 are used to force the elastic spring 2 to expand radially, pressing the O-ring 3 against the inner wall of the cylinder liner 7. Then, the friction force generated by the upward lifting device pulls the cylinder liner 7 out of the cylinder body 8.

[0036] like Figure 3 As shown, the anti-rotation guide 5 includes a fixed sleeve 51, which is sleeved on the middle part of the core rod 1. The fixed sleeve 51 has a guide groove 511 extending axially at its end. An anti-rotation pin 52 is passed through the core rod 1 and is slidably fitted in the guide groove 511 to restrict the core rod 1 from rotating relative to the fixed sleeve 51.

[0037] Specifically, such as Figure 7 As shown, the fixing sleeve 51 is a hollow cylinder, and the anti-rotation pin 52 is a cylindrical pin, specifically a 3r6×18 type cylindrical pin as specified in GB / T119.1-2000, which is interference-fitted with the pin hole of the core rod 1 to ensure that it will not fall off during use. The fixing sleeve 51 is also equipped with a convenient clamping handle 6, which is horizontally inserted on both sides of the fixing sleeve 51. During use, the clamping handle 6 provides an auxiliary force application point; by gripping the fixing sleeve 51, downward pressure is applied to the device to prevent the fixing sleeve 51 from rotating with the driving component 4.

[0038] Specifically, such as Figure 4 As shown, in this embodiment, the cone angle of the conical head 11 of the core rod 1 is 20°, and the elastic spring 2 has an inner conical surface that matches the outer conical surface of the conical head 11 of the core rod 1, with the matching cone angle also being 20°; when the handle moves 1mm, the diameter of the elastic spring 2 can increase by 0.35mm. Figure 5 As shown, the elastic spring 2 is cylindrical and made of 65Mn spring steel with a hardness of HRC45~50, which ensures that the friction generated during the lifting of the handle can drive the cylinder liner 7 to move.

[0039] like Figure 5-6As shown, six axial through slots 21 are evenly distributed circumferentially on the side wall of the elastic spring 2. A circular stress relief hole 22 is drilled at the starting end of each slot (i.e., near the root of the elastic spring 2) to ensure uniform deformation of the elastic spring 2 under stress. Six O-rings 3 are fitted around the outer circumference of the elastic spring 2. These six O-rings 3 are arranged along the axial direction of the spring, and a protruding edge 23 for fixing the O-rings 3 is provided at the end of the axial through slots 21 of the elastic spring 2.

[0040] like Figure 8 As shown, the drive component 4 is a handle, and the outer surface of the handle is provided with anti-slip texture or knurling for easy gripping and application of force by the operator. A threaded hole 41 is opened at the bottom of the drive component 4, and an external threaded portion 12 is provided at the top of the core rod 1; as shown... Figure 3 As shown, the external threaded portion 12 of the core rod 1 is rotated and inserted into the threaded hole 41 of the drive member 4, and the core rod 1 moves up and down relative to the fixed sleeve 51 by rotating the thread.

[0041] refer to Figure 1-8 As shown, the operation process and principle of the present invention are as follows:

[0042] The operator inserts the small end of the device (i.e., the elastic spring 2 and O-ring 3) into the cylinder liner 7 (e.g.) Figure 2 As shown, the elastic spring 2 protrudes approximately 5mm from the opening of the cylinder liner 7. Hold the retaining sleeve 51 with one hand, pressing your fingers on the clamping handle 6 that passes laterally through the retaining sleeve 51, and rotate the handle clockwise with the other hand. Because the anti-rotation pin 52 slides within the guide groove 511, restricting the rotation of the core rod 1, the rotating handle causes the core rod 1 to move axially upward relative to the retaining sleeve 51 and the elastic spring 2. The outer conical surface of the tapered head 11 of the core rod 1 presses upward against the inner conical surface of the elastic spring 2, forcing the segments formed by the multiple axial through grooves 21 of the elastic spring 2 to expand radially outward, thereby pressing the O-ring 3 around its outer circumference against the inner wall of the cylinder liner 7, generating sufficient positive pressure. The operator lifts the core rod 1 upward by rotating the handle, raising the entire device upward. The friction between the O-ring 3 and the inner wall of the cylinder liner 7 causes the cylinder liner 7 to move upward until it is completely pulled out of the cylinder body 8. After disassembly, rotate the handle in the opposite direction to move the core rod 1 down. The elastic spring 2 will automatically retract back to its initial diameter under its own elasticity, and the cylinder liner 7 can then be removed from the device.

[0043] This invention offers the following technical advantages: First, by using an O-ring as the friction medium, direct contact between metal parts and the inner wall of the cylinder liner is avoided, achieving non-destructive disassembly without scratching the workpiece surface. Second, the conversion from rotary motion to linear motion is achieved through conical surface fitting and anti-rotation guide components, allowing for disassembly by a single operator. Third, the elastic spring uses spring steel with a hardness controlled within the HRC 45-50 range, and its sidewall is grooved with stress relief holes, ensuring uniform deformation under stress and preventing the cylinder liner from becoming misaligned or stuck during removal. Furthermore, it automatically returns to its initial state after the external force is removed. Fourth, the 20° cone angle design ensures a reasonable linear relationship between axial movement and radial diameter expansion, preventing excessive compression that could damage the O-ring. In summary, this embodiment provides a compact, easy-to-operate, reliable, durable, and non-damaging cylinder liner disassembly device.

[0044] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. An auxiliary disassembly device for cylinder liners, comprising a core rod (1), characterized in that: The end of the core rod (1) is a tapered head (11), which is fitted inside a radially expandable elastic spring (2). At least one O-ring (3) is fitted around the outer periphery of the elastic spring (2). A drive member (4) is connected to the upper end of the core rod (1), and an anti-rotation guide member (5) is fitted on the core rod (1) below the drive member (4) to prevent the core rod (1) from rotating. The core rod (1) is inserted into the cylinder liner (7) of the cylinder body (8); the driving member (4) drives the core rod (1) to move linearly along the axial direction, and the elastic spring (2) is forced to expand radially by the cooperation between the outer conical surface of the conical head (11) and the inner conical surface of the elastic spring (2), pressing the O-ring (3) against the inner wall of the cylinder liner (7); so that the cylinder liner (7) moves upward with the core rod (1) and is then pulled out from the cylinder body (8).

2. The auxiliary disassembly device for cylinder liners according to claim 1, characterized in that: The anti-rotation guide (5) includes a fixed sleeve (51), which is sleeved on the outside of the core rod (1). The fixed sleeve (51) has a guide groove (511) extending axially at its end. An anti-rotation pin (52) is provided on the core rod (1), and the anti-rotation pin (52) is slidably engaged in the guide groove (511) to restrict the core rod (1) from rotating relative to the fixed sleeve (51).

3. The auxiliary disassembly device for cylinder liners according to claim 2, characterized in that: The fixing sleeve (51) is also equipped with a pressing handle (6) for easy operation.

4. The auxiliary disassembly device for cylinder liners according to claim 1 or 3, characterized in that: The elastic spring (2) has multiple axial through grooves (21) circumferentially opened on the side wall. Each axial through groove (21) has a stress relief hole (22) at the beginning end and a protruding edge (23) for fixing an O-ring (7) at the end.

5. The auxiliary disassembly device for cylinder liners according to claim 1, characterized in that: The drive member (4) has a threaded hole (41) at one end, and the core rod (1) has an external threaded part (12) at the top. The external threaded part (12) of the core rod (1) cooperates with the threaded hole (41) on the drive member (4), and the core rod (1) moves up and down in the threaded hole (41) by rotating the thread.

6. The auxiliary disassembly device for cylinder liners according to claim 5, characterized in that: The O-rings (3) are provided in six units.

7. The auxiliary disassembly device for cylinder liners according to claim 1, characterized in that: The outer cone angle between the outer cone surface of the conical head (11) of the core rod (1) and the inner cone surface of the elastic spring (2) is 20°.

8. The auxiliary disassembly device for cylinder liners according to claim 5, characterized in that: The outer peripheral surface of the drive component (4) is provided with anti-slip mesh or knurling.

9. The auxiliary disassembly device for cylinder liners according to claim 4, characterized in that: The elastic spring (2) is made of spring steel with a hardness of HRC45-50.

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