A general-purpose internal expansion clamp

Abstract

This utility model belongs to the field of tooling and fixture technology, specifically disclosing a general-purpose internal hole expansion clamp, including a base, a positioning sleeve, and a driving component. A vertical positioning boss is fixedly provided on the top surface of the base, and the positioning sleeve is sleeved on the positioning boss. The positioning boss is a frustum structure with its radial dimension gradually increasing from top to bottom. The driving component is installed on the base and includes a driving cover plate. The bottom surface of the driving cover plate is attached to and abuts against the top surface of the positioning sleeve. The driving cover plate can be driven to move in the vertical direction, and the positioning sleeve moves accordingly, so that it is squeezed by the positioning boss and expands radially outward. The positioning sleeve has an elastic contraction force inward along its own radial direction, and under the action of its own elastic contraction force, the positioning sleeve has a tendency to contract radially inward. This utility model utilizes the conical structure of the positioning boss and the elastic deformation of the positioning sleeve to achieve rapid clamping of the workpiece, effectively improving production efficiency and ensuring consistent processing quality.

Description

Technical Field

[0001] This utility model belongs to the field of tooling and fixture technology, and in particular relates to a general-purpose internal hole expansion fixture. Background Technology

[0002] In the machining of blind hole parts such as valve sleeves and valve bodies, these parts have extremely high requirements for dimensional and positional accuracy of the outer diameter, end face, and the hole at the other end relative to the reference hole. Therefore, they usually need to be machined by turning the parts around. For parts with larger hole diameters, a chuck clamping method can be used; however, when encountering parts with smaller hole diameters or smaller parts, turning the parts around becomes a tricky process problem.

[0003] The current industry standard solution involves assembling the internal support fixture with the workpiece under the machine tool, and then mounting the assembly onto the machine tool for machining. While this method meets machining accuracy requirements, it has significant drawbacks: the fixture needs to be disassembled and reassembled for each part, and adjustments must be made after each assembly. This repetitive disassembly and adjustment not only greatly reduces production efficiency but also makes it difficult to ensure the consistency of machining quality for parts in the same batch, seriously affecting product yield and production efficiency. Furthermore, existing internal support fixtures are often complex in structure and inconvenient to adjust, and are prone to wear during frequent disassembly and assembly, further exacerbating the problem of unstable machining accuracy.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Utility Model Content

[0005] The purpose of this utility model is to provide a universal internal expansion clamp, which has the advantages of improving production efficiency, ensuring consistent processing quality, and simplifying the operation process, and effectively solves the problem of frequent disassembly and calibration required by traditional clamps.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: a universal internal expansion clamp, comprising a base, a positioning sleeve, and a driving component. A vertical positioning boss is fixedly provided on the top surface of the base, and the positioning sleeve is sleeved on the positioning boss. The positioning boss is a frustum structure with its radial dimension gradually increasing from top to bottom. The driving component is installed on the base and includes a driving cover plate. The bottom surface of the driving cover plate is attached to and abuts against the top surface of the positioning sleeve. The driving cover plate can be driven to move vertically, and the positioning sleeve moves accordingly so that it is squeezed by the positioning boss and expands radially outward. The positioning sleeve has an elastic contraction force inward along its own radial direction, and under the action of its own elastic contraction force, the positioning sleeve has a tendency to contract radially inward.

[0007] Furthermore, it also includes a locking adjustment component, a positioning boss with an installation channel along the central axis, a driving component including a driving rod that passes through the installation channel, a driving cover plate fixedly installed on the top of the driving rod, and a locking adjustment component detachably installed on the bottom of the driving rod to limit the driving component to the base.

[0008] Furthermore, the bottom surface of the base is recessed upwards in the vertical direction to form an adjustment cavity, and the locking adjustment component is set inside the adjustment cavity.

[0009] Furthermore, the positioning sleeve is provided with multiple open slots, which are through slot structures that extend along the axial direction of the positioning sleeve and are open on one side; the multiple open slots are evenly distributed along the circumference of the positioning sleeve, and the opening directions of any adjacent open slots are opposite.

[0010] Furthermore, the locking adjustment component is an adjusting nut, and the lower part of the drive rod is provided with an external thread. The locking adjustment component is installed on the drive rod by means of a threaded connection, and the locking adjustment component can be driven to rotate, so as to drive the drive component to move in the vertical direction.

[0011] Furthermore, it also includes an adjusting wrench for operating the locking adjustment mechanism, the adjusting wrench being detachably connected to the adjusting nut.

[0012] Furthermore, the base is provided with an operating cavity that connects the adjustment cavity to the outside, and the operating wrench is provided in the operating cavity from the outside along the radial direction of the base.

[0013] Furthermore, the inner wall surface of the positioning sleeve is a conical surface that conforms to the outer surface of the positioning boss.

[0014] The beneficial effects of this technical solution are as follows:

[0015] This utility model discloses a universal internal expansion clamp. Through the cooperative design of the base, positioning sleeve and driving component, the workpiece is quickly clamped by utilizing the conical structure of the positioning boss and the elastic deformation of the positioning sleeve. This solves the problem of frequent disassembly and calibration required by traditional clamps, and has the advantages of improving production efficiency, ensuring consistent processing quality and simplifying the operation process. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the structure of a general-purpose internal expansion clamp according to the present invention;

[0017] Figure 2 for Figure 1 Sectional view at point AA;

[0018] Figure 3 This is a schematic diagram of the cooperation structure between the operating wrench and the locking adjustment component of a general-purpose internal expansion clamp according to this utility model;

[0019] Figure 4This is a schematic diagram of the positioning sleeve of a general-purpose internal expansion clamp according to the present invention. Detailed Implementation

[0020] The following detailed description illustrates the specific implementation method:

[0021] The reference numerals in the accompanying drawings include: base 1, positioning sleeve 2, drive cover plate 3, locking adjustment component 4, drive rod 5, positioning boss 6, adjustment cavity 7, operating cavity 8, adjustment wrench 9, and opening slot 10.

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. In this embodiment, unless otherwise specified, the axial direction is the vertical direction, and the radial direction is the horizontal direction, that is, the direction perpendicular to the axis.

[0023] The basic implementation examples are as follows: Figure 1-4As shown: A general-purpose internal expansion clamp includes a base 1, a positioning sleeve 2, and a driving component. A vertical positioning boss 6 is fixedly provided on the top surface of the base 1. The positioning sleeve 2 is fitted over the positioning boss 6. The positioning boss 6 is a frustum structure with its radial dimension gradually increasing from top to bottom. The driving component is installed on the base 1 and includes a driving cover plate 3. The bottom surface of the driving cover plate 3 abuts against the top surface of the positioning sleeve 2. The driving cover plate 3 can be driven to move vertically, and the positioning sleeve 2 moves accordingly, causing it to expand radially outward due to the pressure from the positioning boss 6. The positioning sleeve 2 has an elastic contraction force inward along its own radial direction, and under the action of its own elastic contraction force, the positioning sleeve 2 tends to contract radially inward. Specifically, the base 1 is a prism or cylinder structure; in this embodiment, a cylinder is preferred. The base 1 mainly serves as a fixing and supporting foundation, fixed to a machining device such as a lathe. The truncated cone structure of the positioning boss 6, with its smaller upper part and larger lower part, results in a conical outer surface. The positioning sleeve 2 is a thin-walled part, similar to a spring clip, and can be made of elastic materials such as spring steel. Its outer surface mates with the workpiece hole. In a preferred embodiment, the inner wall of the positioning sleeve 2 is a conical surface conforming to the outer surface of the positioning boss 6; that is, the inner wall of the positioning sleeve 2 adopts a conical design, which matches the shape of the outer surface of the positioning boss 6. The driving method of the drive cover plate 3 can be manual screw drive, hydraulic drive, or pneumatic drive, etc. Thus, the movable drive cover plate 3 drives the positioning sleeve 2 to move along the conical positioning boss 6, using the conical surface mating to achieve radial tension. When the drive cover plate 3 is pressed down, the positioning sleeve 2 is compressed by the conical surface, resulting in radial expansion, thereby achieving precise positioning and reliable clamping of the workpiece's inner hole. After the external force is removed, the positioning sleeve 2 returns to its initial state due to its own elasticity, facilitating workpiece loading and unloading. Compared to existing technologies, this fixture features a simple and compact structure, is easy to operate, and effectively solves the clamping challenges in machining small-sized blind hole parts, significantly improving clamping efficiency and machining accuracy consistency. Furthermore, the inner wall of the positioning sleeve 2 is designed as a conical surface conforming to the positioning boss 6, resolving the problem of uneven clamping force distribution caused by uneven contact between the fixture and the workpiece in existing technologies. Because the conical surface fit enables self-centering, the positioning sleeve 2 expands evenly outward when the drive cover plate 3 is pressed down, ensuring a symmetrical distribution of radial force applied to the inner hole of the workpiece. Compared to planar contact, the conical surface fit significantly improves the fixture's positioning accuracy and repeatability, making it particularly suitable for machining high-precision valve sleeve parts. In addition, this structural design allows the fixture to maintain good coaxiality even after prolonged use, reducing accuracy degradation due to wear.

[0024] In this embodiment, a locking adjustment component 4 is also included. The positioning boss 6 has an installation channel along its central axis. The driving component also includes a driving rod 5, which passes through the installation channel. The driving cover plate 3 is fixedly installed on the top of the driving rod 5. The locking adjustment component 4 is detachably installed on the bottom of the driving rod 5 to limit the driving component to the base 1. Specifically, the locking adjustment component 4 can be detachably installed with the driving rod 5 using threaded connections, snap-fit ​​connections, or pin connections. By setting the locking adjustment component 4, the detachable limiting of the driving component is achieved, simplifying the clamping process, improving clamping efficiency and accuracy, and ensuring clamping reliability.

[0025] In this embodiment, the bottom surface of the base 1 is recessed vertically upward to form an adjustment cavity 7, and the locking adjustment component 4 is disposed within the adjustment cavity 7. Specifically, the adjustment cavity 7 is a recessed structure formed by machining the bottom surface of the base 1, and its depth and shape are determined according to the size of the locking adjustment component 4 and the operating space requirements. Thus, by providing the adjustment cavity 7 in the base 1, the locking adjustment component 4 can be completely accommodated inside the base 1, thereby effectively reducing the overall height of the fixture and external protruding structures. This design makes the fixture more compact during installation and use, avoiding interference with machine tools or other equipment. At the same time, the adjustment cavity 7 provides protection for the locking adjustment component 4, preventing chips or coolant in the external environment from directly contacting the locking adjustment component 4, thereby improving the service life and reliability of the fixture. This technical solution solves the interference problem and insufficient protection problem caused by the exposed locking adjustment component 4 in traditional fixtures, enabling the fixture to work stably even in confined spaces or complex working conditions.

[0026] In this embodiment, the positioning sleeve 2 is provided with multiple open slots 10. Each open slot 10 is a through-slot structure extending axially along the positioning sleeve 2 and open on one side. The multiple open slots 10 are evenly distributed circumferentially along the positioning sleeve 2, and the opening directions of any adjacent open slots 10 are opposite. Specifically, the through-slot structure of the open slots 10 means that the open slots 10 are radially continuous in the positioning sleeve 2, and the openings of adjacent open slots 10 are located at opposite ends of the axial direction of the positioning sleeve 2, so that the opening directions are opposite. The open slots 10 can be machined using wire cutting or milling processes, and the bottom of the slot can be designed with a rounded transition to avoid stress concentration. Thus, through the specific arrangement of the open slots 10, the positioning sleeve 2 can generate uniform radial deformation when subjected to axial pressure. Furthermore, the arrangement of the open slots 10 ensures that when the drive cover plate 3 is pressed down, the positioning sleeve 2 expands outward under the action of the conical surface of the positioning boss 6. The symmetrical and opposite arrangement of the open slots 10 effectively avoids the problem of stress concentration on one side, while ensuring a uniform distribution of the workpiece clamping force. Compared to the traditional integral positioning sleeve 2, this design significantly improves the positioning accuracy and repeatability of the fixture, making it particularly suitable for the machining requirements of high-precision valve sleeve parts.

[0027] In this embodiment, the locking adjustment component 4 is an adjusting nut, and the lower part of the drive rod 5 is provided with an external thread. The locking adjustment component 4 is installed on the drive rod 5 through a threaded connection, and the locking adjustment component 4 can be driven to rotate, thereby driving the drive component to move in the vertical direction. Specifically, the threaded engagement between the adjusting nut and the drive rod 5 realizes the axial movement control of the drive component. The rotation of the adjusting nut can be achieved by manual tools or power tools, such as using a hex wrench, socket wrench, or pneumatic wrench. Thus, this technical solution achieves precise adjustment of the drive component's position through a threaded transmission mechanism. When the adjusting nut rotates, due to the action of the threaded pair, the drive rod 5 drives the drive cover plate 3 to generate axial displacement, thereby controlling the tension of the positioning sleeve 2. Compared with the prior art, which requires repeated disassembly and assembly of tooling, this structure can complete the position adjustment without disassembling the fixture, significantly improving processing efficiency. At the same time, the threaded transmission has a self-locking characteristic, which can maintain a stable clamping force and ensure the positioning accuracy of the workpiece during processing. This design is particularly suitable for machining scenarios that require frequent workpiece changes. The fixture state can be adjusted through a simple rotation operation, avoiding the tedious process of repeated calibration in traditional methods.

[0028] In this embodiment, an adjusting wrench 9 for operating the locking adjusting component 4 is also included. The adjusting wrench 9 is detachably connected to the adjusting nut. Specifically, the connection between the adjusting wrench 9 and the adjusting nut can take various forms. For example, the outer circumferential surface of the adjusting nut can be provided with multiple grooves or protrusions, and the inner side of the adjusting wrench 9 is provided with corresponding protrusions or grooves, achieving a detachable connection through insertion or snap-fit. As a preferred embodiment, the outer circumferential surface of the adjusting nut can be set as a hexagonal structure, and the adjusting wrench 9 is provided with an opening groove 10 conforming to the shape of the adjusting nut, achieving a connection through insertion. Thus, by providing the adjusting wrench 9, the operator can more conveniently rotate the adjusting nut, thereby driving the driving component to move in the vertical direction.

[0029] In this embodiment, the base 1 is provided with an operating cavity 8 that connects the adjustment cavity 7 to the outside. The operating wrench is installed radially from the outside into the operating cavity 8. Specifically, the operating cavity 8 is a channel structure that penetrates the side wall of the base 1. The size of the operating cavity 8 is designed according to the operating space requirements of the adjusting wrench 9. In this embodiment, it is set as a fan-shaped structure. By setting the radially penetrating operating cavity 8, the adjusting wrench 9 can directly operate the locking and adjusting component 4 without disassembling the fixture. The operating cavity 8 provides radial operating space for the adjusting wrench 9. The operator can directly insert the wrench from the outside of the base 1 and rotate the adjusting nut to drive the drive rod 5 to move up and down. This design avoids the operation steps of disassembling the fixture or using special tools in the traditional method, which significantly improves the clamping efficiency. Since the adjustment process does not require disassembling the workpiece or fixture, the positioning accuracy is maintained during repeated clamping, thereby ensuring the consistency of part quality in batch processing.

[0030] The specific implementation process is as follows: Fix the fixture to the machine tool via the base 1 and adjust the fixture. Then, place the part to be processed onto the outer surface of the positioning sleeve 2. Then, turn the locking adjustment component 4 with the operating wrench to make the drive rod 5 move vertically, thereby causing the positioning sleeve 2 to expand and tighten the part to be processed. When it is necessary to remove the part, turn the locking adjustment component 4 in the opposite direction with the operating wrench. The drive rod 5 moves in the opposite direction, and the positioning sleeve 2 contracts under its own elastic contraction force, so that the part can be released and removed.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] The above descriptions are merely embodiments of this utility model. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are knowledgeable of all existing technologies in that field, and possess the ability to apply conventional experimental methods prior to that date. Therefore, those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in conjunction with their own capabilities. Typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A universal in-hole expansion clamp, characterized by: The device includes a base, a positioning sleeve, and a driving component. A vertical positioning boss is fixedly provided on the top surface of the base. The positioning sleeve is fitted over the positioning boss, which is a frustum structure with its radial dimension gradually increasing from top to bottom. The driving component is mounted on the base and includes a driving cover plate. The bottom surface of the driving cover plate abuts against the top surface of the positioning sleeve. The driving cover plate can be driven to move vertically, and the positioning sleeve moves accordingly, causing it to expand radially outward due to the pressure from the positioning boss. The positioning sleeve has an elastic contraction force radially inward, and under the action of this elastic contraction force, it tends to contract radially inward.

2. A universal in-hole expansion clamp as defined in claim 1, wherein: It also includes a locking adjustment component. The positioning boss has an installation channel along the central axis. The driving component also includes a driving rod, which passes through the installation channel. The driving cover is fixedly installed on the top of the driving rod. The locking adjustment component is detachably installed on the bottom of the driving rod to limit the driving component to the base.

3. A general-purpose internal expansion clamp according to claim 2, characterized in that: The bottom surface of the base is recessed vertically upward to form an adjustment cavity, and the locking adjustment component is disposed in the adjustment cavity.

4. A general-purpose internal expansion clamp according to claim 3, characterized in that: The positioning sleeve is provided with multiple open slots, which are through slot structures that extend along the axial direction of the positioning sleeve and are open on one side; the multiple open slots are evenly distributed along the circumference of the positioning sleeve, and the opening directions of any adjacent open slots are opposite.

5. A general-purpose internal expansion clamp according to claim 4, characterized in that: The locking adjustment component is an adjusting nut. The lower part of the drive rod is provided with an external thread. The locking adjustment component is installed on the drive rod by means of a threaded connection, and the locking adjustment component can be driven to rotate so as to drive the drive component to move in the vertical direction.

6. A general-purpose internal expansion clamp according to claim 5, characterized in that: It also includes an adjusting wrench for operating the locking adjustment element, the adjusting wrench being detachably connected to the adjusting nut.

7. A general-purpose internal expansion clamp according to claim 6, characterized in that: The base is provided with an operating cavity that connects the adjustment cavity to the outside, and an operating wrench is provided in the operating cavity from the outside along the radial direction of the base.

8. A general-purpose internal expansion clamp according to claim 7, characterized in that: The inner wall surface of the positioning sleeve is a conical surface that conforms to the outer surface of the positioning boss.

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