A pre-assembly tool for slotted bushings

Abstract

This utility model discloses a pre-assembly tool for slotted bushings, comprising a top sleeve, a spring, a spring rod, and a nut. The top sleeve has an axial tapered hole at its center for a mandrel to pass through. The left end has a uniformly tapered opening at an angle for inserting the slotted bushing, with the diameter of the tapered opening smaller than the major diameter of the flanged area of ​​the slotted bushing. The top sleeve is divided into two symmetrical parts, connected by the spring rod and nut. The spring passes through the spring rod and is in an extended state in its free state, thus opening the tapered area at the left end of the top sleeve. During operation, the tool is held in hand, using the tapered area at the left end of the top sleeve to hold the slotted bushing, aligning the bushing with the mandrel, and pressing the top sleeve downwards. After the slotted bushing is inserted into the mandrel, the grip on the top sleeve is reduced, thus opening the tapered area. The top sleeve is then removed, completing the slotted bushing assembly. This structure is highly versatile, safe and labor-saving to operate, and provides precise and efficient assembly. It offers extreme simplicity and low cost, along with extremely high reliability and portability.

Description

Technical Field

[0001] This utility model relates to the field of mechanical assembly tooling technology, and in particular to a pre-assembly tool for slotted bushings. Background Technology

[0002] In high-precision manufacturing fields such as aerospace, a process is often used where a mandrel is pressed into a workpiece hole through a slotted bushing to improve the hole's fatigue strength. This process requires the slotted bushing to maintain extremely high coaxiality and a tight fit with the mandrel.

[0003] Currently, the slotted bushing is typically installed onto the mandrel manually on-site. Because the slotted bushing is a thin-walled elastic element with an axial slot, its inner diameter in its free state is slightly smaller than the outer diameter of the mandrel. During assembly, it requires force to open the bushing or to directly insert it into the mandrel and then press it downwards to fit it in. This manual operation has significant drawbacks: 1. Difficult assembly and low efficiency: The operator needs to expend a lot of physical strength and it is difficult to align.

[0004] 2. Easily damaged bushings: Improper operation can easily lead to permanent deformation and out-of-roundness of the thin wall of the bushing, or scratches on its inner and outer surfaces, which seriously affects the quality of subsequent extrusion processes and may even cause the bushing to be scrapped.

[0005] 3. Poor assembly consistency: Manual operation cannot guarantee that the position and tightness of each assembly are consistent, which affects the stability of the process.

[0006] Therefore, there is an urgent need in this field for a specialized tool that can achieve rapid and standardized assembly. Existing pre-assembly tools consist of a top cover, spring, clamping block, top sleeve, housing, base, and spring seat block, which have many components and are therefore inefficient. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the existing technology, which involves many assembly parts, and to provide an auxiliary tool with a simple structure and convenient operation for assembling a slotted liner onto a mandrel.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A pre-assembly tool for a slotted bushing consists of a top sleeve, a spring, a nut, and a spring. One end of the top sleeve is a conical section, and the other end is a cylindrical section, forming a hollow cylindrical structure. The inner diameter of the cylindrical section gradually increases from left to right, while the inner diameter of the conical section gradually decreases from left to right. The top sleeve consists of two interlocking semi-cylindrical half-covers. Each half-cover has a connecting hole near the conical section, and the two connecting holes are symmetrically arranged. The spring rod, with both ends of the spring passing through the two connecting holes, connects the two half-covers through the nut.

[0009] Furthermore, the cylindrical segment has a guide slope at its port for inserting a slotted bushing, and the closing diameter is smaller than the large diameter of the flanged area of ​​the slotted bushing.

[0010] Furthermore, the cylindrical segment is provided with several axial grooves along the axial direction.

[0011] Furthermore, the top sleeve is made of spring steel.

[0012] The top sleeve is divided into two symmetrical parts, connected by a spring rod and two nuts. The spring passes through the spring rod and is in an extended state in its free state, causing the constricted area of ​​the cylindrical section of the top sleeve to be open. During operation, when held and pressed down, the spring is compressed, and the cylindrical section of the top sleeve becomes a single unit. To operate, hold this auxiliary tool and use the cylindrical section of the top sleeve to grip the slit bushing, aligning the slit bushing with the mandrel, and press the top sleeve downwards. After the slit bushing is inserted into the mandrel, reduce the grip on the top sleeve, thus opening the cylindrical section of the top sleeve. Remove the top sleeve; the slit bushing assembly is complete. During operation, because the interior of the cylindrical section of the top sleeve is conical, it does not interfere with the interior of the top sleeve after the slit bushing is inserted into the mandrel.

[0013] An auxiliary tool for fitting a slotted liner to a mandrel, the assembly comprising the following steps: Step S1: Gather the top sleeve, spring, and nut parts of the corresponding specifications for the slotted bushing, and assemble them into a whole; Step S2: Use the guide slope of the cylindrical segment end to clamp the slotted bushing; Step S3: Align the clamped slit bushing with the top of the mandrel, press the top sleeve, and under the action of the mandrel, the cylindrical section of the top sleeve opens, but is smaller than the maximum diameter of the slit bushing flange, and the working section of the mandrel passes through the slit bushing. Step S4: After the lining is assembled, reduce the grip of your hand on the top sleeve. The cylindrical section of the top sleeve will open automatically, and the top sleeve can be removed.

[0014] The cylindrical section of the top sleeve has a segmented, tapered end with an angle that can be arbitrarily adjusted. The length of the conical region inside the cylindrical section can be varied according to the length of the slotted bushing. The connection method after the top sleeve is segmented is flexible and not limited to using spring rods and nuts. The number of segments can be adjusted according to the outer diameter of the slotted bushing and assembly precision requirements, commonly using a two- or three-segment structure to ensure stable clamping and smooth release. In actual operation, the tapering diameter can be precisely adjusted by controlling the pressing force, preventing bushing deformation or surface damage. This tool is suitable for work conditions with limited space or high assembly torque requirements, significantly improving assembly efficiency and consistency. The top sleeve design fully considers the balance between material elasticity and structural stability; the selection of spring steel ensures rebound performance under long-term use. The segmented structure, combined with axial grooves, enhances the flexible deformation capability of the tapered end and avoids fatigue cracking caused by stress concentration. The guide slope reduces the difficulty of alignment in the initial assembly stage and improves operational error tolerance. In practical applications, the tool's modular design allows for quick replacement of top bushings to fit different bushing specifications, further expanding its applicability. Its simple structure and lack of an additional power source make it particularly suitable for assembly lines or on-site maintenance scenarios.

[0015] The beneficial effects of this utility model are: 1. High versatility: By manufacturing a series of top sleeves of different specifications, it can be adapted to mandrels and slotted bushings of various sizes, thus achieving high versatility.

[0016] 2. Safe and labor-saving operation; reduces the labor intensity and skill requirements of operators, and eliminates safety hazards caused by manual operation.

[0017] 3. Precise and efficient assembly: Tool-based operation transforms complex radial assembly into simple axial advancement, which can be completed simply by pressing. The assembly process is smooth, the position is accurate, and the consistency is good, which significantly improves assembly efficiency and quality stability.

[0018] 4. Extreme simplicity and low cost: The entire tool consists of only two parts, with an extremely simple structure, which greatly reduces manufacturing, management and maintenance costs.

[0019] 5. Extremely high reliability and portability: Fewer parts, minimal points of failure, and high reliability. The tool is small and lightweight, making it ideal for various scenarios such as production lines and on-site maintenance. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments conforming to the present invention and, together with the description, serve to explain the principles of the present invention. It is obvious that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0021] Figure 1 A schematic diagram of the pre-assembly tool for the slotted bushing provided by this utility model; Figure 2 A perspective view of the pre-assembly tool for the slotted bushing provided by this utility model; Figure 3 A schematic diagram of the top sleeve provided by this utility model; Figure 4 A schematic diagram showing the slit bushing pre-assembly tool provided by this utility model equipped with a slit bushing; Figure 5 A schematic diagram of step S2 of the pre-installation tool for the slotted bushing provided by this utility model; Figure 6 A schematic diagram of step S3 for assembling the slotted bushing pre-assembly tool provided by this utility model; Figure 7 A schematic diagram of step S4 for assembling the slotted bushing pre-assembly tool provided by this utility model; Among them: 1-top sleeve, 2-spring, 3-spring rod, 4-nut, 101-conical section, 102-cylindrical section, 103-half cover, 104-connecting hole, 105-guide slope, 106-axial groove. Detailed Implementation

[0022] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0023] Please see Figures 1-7 The figure shows a schematic diagram of the pre-assembly tool for the slotted bushing provided by this utility model, including a top sleeve 1, a spring 2, a spring rod 3, and a nut 4. The top sleeve 1 has a conical section 101 at one end and a cylindrical section 102 at the other, forming a hollow cylindrical structure. The inner diameter of the cylindrical section 102 gradually increases from left to right, while the inner diameter of the conical section 101 gradually decreases from left to right. The top sleeve 1 consists of two interlocking semi-cylindrical half-covers 103. Each half-cover 103 has a connecting hole 104 at its end closest to the conical section 101, and the two connecting holes 104 are symmetrically arranged. The spring rod 3, fitted with the spring 2, passes through the two connecting holes 104 and is connected to the two half-covers 103 by the nut 4. The cylindrical section 102 has several axial grooves 106 along its axial direction. The end of the cylindrical section 102 has a guide slope 105, the minimum diameter of which is smaller than the major diameter of the flanged area of ​​the slotted bushing. The top sleeve 1 is made of spring steel.

[0024] The top sleeve 1 is divided into two symmetrical half-covers 103, connected as a whole by a spring rod 3 and two nuts 4. The spring 2 passes through the spring rod 3 and is in an extended state in its free state, causing the guide slope 105 area of ​​the cylindrical section 101 of the top sleeve 1 to be open. During operation, when held and pressed, the spring 2 is compressed, and the guide slope 105 at the end of the cylindrical section 101 of the top sleeve 1 forms a whole. During operation, holding this auxiliary tool, the slit bushing 5 is clamped by the guide slope 105 at the end of the cylindrical section 101 of the top sleeve 1. The slit bushing 5 is aligned with the mandrel 6, and the top sleeve 1 is pressed downwards. After the slit bushing 5 is inserted into the mandrel 6, the grip force on the top sleeve 1 is reduced, thus opening the guide slope 105 at the end of the cylindrical section 101 of the top sleeve 1. The top sleeve 1 is then removed, and the assembly of the slit bushing 5 is complete. During operation, the conical interior of the cylindrical section 102 of the top sleeve 1 compensates for the change in diameter of the mandrel 6 after it is fitted into the slit bushing 5, preventing interference between the slit bushing 5 and the interior of the top sleeve 1 after the mandrel 6 is fitted into it. This reduces the operator's workload and skill requirements, and eliminates safety hazards associated with manual operation.

[0025] An auxiliary tool for fitting a slotted liner to a mandrel, the assembly comprising the following steps: Step S1: Gather the top sleeve, spring, and nut parts of the corresponding specifications for the slotted bushing, and assemble them into a whole; Step S2: Use the guide slope of the cylindrical segment end to clamp the slotted bushing; Step S3: Align the clamped slit bushing with the top of the mandrel, press the top sleeve, and under the action of the mandrel, the cylindrical section of the top sleeve opens, but is smaller than the maximum diameter of the slit bushing flange, and the working section of the mandrel passes through the slit bushing. Step S4: After the lining is assembled, reduce the grip of your hand on the top sleeve. The cylindrical section of the top sleeve will open automatically, and the top sleeve can be removed.

[0026] The cylindrical segment 102 of the top sleeve 1 has a split end with an angle that can be arbitrarily changed. The length of the conical region inside the cylindrical segment 102 of the top sleeve 1 can be arbitrarily varied according to the length of the slotted bushing. The connection method after the top sleeve 1 is split can be arbitrarily changed, not limited to using spring rod 3 and nut 4 for connection. By manufacturing a series of top sleeves of different specifications, it can be adapted to mandrels and slotted bushings of various sizes, with high versatility. Precise and efficient assembly: Tool-based operation transforms complex radial assembly into simple axial advancement, which can be completed simply by pressing. The assembly process is smooth, the position is accurate, and the consistency is good, which significantly improves assembly efficiency and quality stability. Fewer parts, very few failure points, and high reliability. The tool is small and lightweight, making it very suitable for various scenarios such as production lines and on-site maintenance. The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, are all covered within the scope of the claims of this utility model.

Claims

1. A tool for pre-assembling slotted bushings, characterized in that: It includes a top sleeve (1), a spring (2), a spring rod (3), and a nut (4); the top sleeve (1) has a conical section (101) at one end and a cylindrical section (102) at the other end, and the whole has a hollow cylindrical structure. The inner diameter of the cylindrical section (102) gradually increases from left to right, and the inner diameter of the conical section (101) gradually decreases from left to right. The top sleeve (1) consists of two semi-cylindrical structures (103) that can be interlocked. The two semi-cylindrical structures (103) are respectively provided with connecting holes (104) at the ends of the two semi-cylindrical structures (101). The two connecting holes (104) are symmetrically arranged. The spring rod (3) is fitted with a spring (2) and its two ends pass through the two connecting holes (104) respectively. The two semi-cylindrical structures (103) are connected by the nut (4).

2. The pre-assembly tool for slotted bushings according to claim 1, characterized in that: The cylindrical segment (102) is provided with a plurality of axial grooves (106) along the axial direction.

3. The pre-assembly tool for slotted bushings according to claim 1, characterized in that: The cylindrical segment (102) has a guide slope (105) at its port, and the minimum diameter of the guide slope (105) is smaller than the maximum diameter of the flanged area of ​​the slotted bushing.

4. The pre-assembly tool for slotted bushings according to claim 1, characterized in that: The top sleeve (1) is made of spring steel.

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