A lathe fixture for clamping thin-walled parts to prevent deformation

Abstract

The utility model relates to the field of gear ring frock, concretely relates to a kind of thin-walled part clamping anti-deformation lathe fixture;Including bottom plate, device ontology, apron, sliding mandrel, screw rod, elastic member, sliding block and inner support claw;The device ontology is fixedly arranged on bottom plate, the apron is fixedly arranged on device ontology;The sliding mandrel is axially slidably arranged in device ontology;The screw rod is threadedly connected with apron, and screw rod lower end acts on the top of elastic member;The bottom of elastic member acts on the upper end of sliding mandrel;The outer periphery of sliding mandrel is equipped with taper face, and sliding block is matched with the taper face, and can slide along radial direction;The inner support claw is installed on sliding block.This device provides clamping force by rotating screw rod compression elastic member, utilizes multiple inner support claw to be able to float compensation under the action of elastic force, evenly sticks to part inner wall, realizes centring clamping, avoids the elastic deformation of part due to local over-stress.

Description

Technical Field

[0001] This utility model relates to the field of gear ring tooling, specifically to a car clamp for holding thin-walled parts to prevent deformation. Background Technology

[0002] In existing high-end equipment manufacturing fields, such as new energy vehicle drive systems, aero-engine transmission mechanisms, and automatic transmissions (AT), thin-walled gear rings are widely used due to their advantages such as lightweight and space saving. These parts are typically made of high-alloy steel and require heat treatment processes such as carburizing or nitriding to achieve high surface hardness, high wear resistance, and high core toughness. However, during heat treatment, uneven structural and thermal stresses are generated inside the part, leading to unpredictable deformation, usually manifested as ellipticization, which poses a challenge to subsequent precision machining.

[0003] To ensure the accuracy and surface quality of the internal teeth after grinding, the fine grinding process must use the turned outer diameter as a unified precision datum. Currently, the industry uses a traditional expansion sleeve fixture in the fine turning process. This fixture drives the expansion sleeve to expand radially through the conical surface engagement, thereby clamping the inner hole of the workpiece to achieve positioning and clamping.

[0004] However, the problem with this rigid tensioning method is that in order to overcome the deformation caused by heat treatment and clamp the workpiece, a large radial clamping force must be applied. For thin-walled gear rings, excessive clamping force will cause elastic deformation, which will lead to loss of internal gear grinding accuracy, high scrap rate, and inability to achieve stable production.

[0005] To address the aforementioned problems, existing technologies offer the following solutions: on the one hand, reducing clamping pressure to decrease deformation; on the other hand, increasing the grinding allowance on the internal tooth surface in the process design to reduce errors through subsequent grinding. However, this approach not only increases grinding wear and production costs, but also, for strictly limited parts such as aerospace gear rings (where the post-heat grinding allowance for internal teeth is required to be ≤0.05mm), there is simply not enough allowance to compensate for errors, thus making it impossible to increase the grinding allowance. Utility Model Content

[0006] The purpose of this invention is to provide a machining fixture for clamping thin-walled parts to prevent deformation. By controlling the magnitude of the clamping force in the circumferential direction, it can quickly align the parts in the circumferential direction without causing deformation. It can clamp and position the parts properly, ensuring the precision machining accuracy of the parts, thus solving the problems in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This utility model proposes a car clamp for clamping thin-walled parts to prevent deformation, including a base plate, a device body, a cover plate, a sliding mandrel, a screw, an elastic element, a slider, and an inner support claw; The device body is fixedly mounted on the base plate, and the cover plate is fixedly mounted on the device body; The sliding mandrel is axially slidably disposed within the device body; The screw is threadedly connected to the cover plate, and the lower end of the screw acts on the top of the elastic element; the bottom of the elastic element acts on the upper end of the sliding spindle. The outer periphery of the sliding mandrel is provided with a conical surface, the slider cooperates with the conical surface and can slide radially; the inner support claw is installed on the slider.

[0008] As a further improvement, the elastic element is sleeved on the lower end of the screw and accommodated in a spring mounting hole provided inside.

[0009] As a further improvement, the elastic element is a cylindrical helical spring.

[0010] As a further improvement, the slider is provided with an inclined surface that matches the conical surface.

[0011] As a further improvement, a stepped positioning pin for positioning the workpiece is also included, the stepped positioning pin being fixedly mounted on the base plate.

[0012] As a further improvement, a pressure plate is also included, which is bolted to the end face of the workpiece to achieve axial positioning and anti-rotation of the workpiece.

[0013] As a further improvement, the cover plate is also provided with a grease fitting.

[0014] As a further improvement, the number of sliders and inner support claws is multiple, and they are evenly distributed along the circumference of the device body.

[0015] As a further improvement, the base plate is used to connect to a three-jaw chuck on a lathe.

[0016] As a further improvement, a calibration element is also included, which is used to calibrate the fixture.

[0017] Compared with the prior art, this utility model achieves the following technical effects: This device provides clamping force by compressing the elastic element through a rotating screw. Multiple internal support claws can float and compensate under the action of elastic force, uniformly conforming to the inner wall of the part to achieve centered clamping. This not only avoids elastic deformation of the part caused by local overstress, but also ensures that the part does not elastically recover after the clamping force is released. This allows the outer diameter datum after precision turning to stably maintain its machining state, providing a process datum for subsequent internal gear grinding.

[0018] The stepped positioning pin of this device enables rapid initial positioning of the workpiece, greatly shortening the clamping and alignment time; the manual adjustment of the screw eliminates the need to modify the existing hydraulic and pneumatic system of the machine tool, and the structure is simple, low-cost, and applicable to various ordinary lathes such as vertical or horizontal lathes, making it highly versatile. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a top view of the structure of this utility model; Figure 3 This is a schematic diagram of the base plate structure of this utility model; Figure 4 This is a schematic diagram of the main structure of the device of this utility model; Figure 5 This is a schematic diagram of the internal support claw structure of this utility model; Figure 6 This is a schematic diagram of the slider structure of this utility model; Figure 7 This is a schematic diagram of the cover plate structure of this utility model; Figure 8 This is a schematic diagram of the sliding mandrel structure of this utility model; Figure 9 This is a schematic diagram of the pressure plate structure of this utility model.

[0020] Reference numerals in the attached drawings: 1. Base plate; 2. Step positioning pin; 3. Device body; 4. Inner support claw; 5. Slider; 6. Cover plate; 7. Sliding spindle; 8. Screw; 9. Shim; 10. Calibration piece; 11. Elastic element; 12. First bolt; 13. Grease nipple; 14. Second bolt; 15. Pressure plate. Detailed Implementation

[0021] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0022] See Figure 1 and Figure 2 This embodiment proposes a car clamp for clamping thin-walled parts to prevent deformation, characterized in that it includes a base plate 1, a device body 3, a cover plate 6, a sliding spindle 7, a screw 8, an elastic element 11, a slider 5, and an inner support claw 4. The device body 3 is fixedly mounted on the base plate 1, and the cover plate 6 is fixedly mounted on the device body 3; the sliding spindle 7 is axially slidably mounted inside the device body 3. The screw 8 is threadedly connected to the cover plate 6, and the lower end of the screw 8 acts on the top of the elastic element 11; the bottom of the elastic element 11 acts on the upper end of the sliding spindle 7. The outer periphery of the sliding mandrel 7 is provided with a conical surface, the slider 5 cooperates with the conical surface and can slide radially; the inner support claw 4 is installed on the slider 5.

[0023] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0024] This device aims to solve the problem of deformation caused by clamping force during the finishing process of thin-walled parts, especially for thin-walled gear ring parts that are prone to elliptical deformation after heat treatment. Traditional rigid expansion sleeve clamps often require the application of large radial clamping forces to overcome heat treatment deformation. However, for thin-walled structures, this can easily cause elastic deformation during clamping. After the clamping force is released, the part springs back, resulting in the loss of accuracy of the machined reference surface. Consequently, the subsequent grinding process based on the inner circle cannot guarantee the accuracy of the teeth.

[0025] The working process of this device is as follows: by manually rotating the screw 8, the elastic element 11 is driven to generate flexible axial pressure. This flexible axial pressure pushes a sliding mandrel 7 with an outer conical surface to generate axial displacement. Through the cooperation between the slider 5 and the conical surface of the sliding mandrel 7, the axial movement of the sliding mandrel 7 can be converted into the radial expansion movement of the slider 5, thereby driving the inner support claw 4 installed at the end of the slider 5 to move outward and contact and tighten the inner wall of the workpiece.

[0026] The entire process is buffered by the elastic element 11, which allows the multiple inner support claws 4 to adapt to the shape of the inner wall of the part and achieve uniform centering and clamping. In addition, the axial positioning of the part and the prevention of rotation during cutting are achieved by the pressure plate 15 pressing the end face, which greatly reduces the clamping deformation of the part.

[0027] The fixture in this embodiment includes a base plate 1, which is disc-shaped. When in use, the base plate 1 is mounted on the three-jaw chuck of the vertical lathe, ensuring the reliable installation and positioning of the fixture as a whole on the machine tool.

[0028] See Figure 3 and Figure 4The device body 3 is fixed to the base plate 1 by the first bolt 12. A gasket 9 is also provided between the device body 3 and the base plate 1. The device body 3 has a mounting hole machined inside. The mounting hole is used to accommodate the sliding spindle 7 to make axial movement, ensuring the coaxiality of the movement and avoiding jamming. In the embodiment, the cover plate 6 is fastened to the upper end of the device body 3 by screws, forming a closed transmission chamber. The cover plate 6 has a threaded hole machined in the center. The threaded hole cooperates with the screw 8. The rotation of the screw 8 can realize axial movement along the direction of the threaded hole.

[0029] In this embodiment, the lower end of the screw 8 is provided with a boss, which is used to contact and compress the elastic element 11 located below it. In this embodiment, the elastic element 11 is preferably a cylindrical helical spring, the specifications of which are adjusted according to the actual use scenario to ensure that a sufficient and adjustable elastic force range can be provided.

[0030] See Figure 8 In this embodiment, the elastic element 11 is set in a spring mounting hole specially machined on the sliding mandrel 7, thereby ensuring the centering and stability of the force. Specifically, the upper part of the sliding mandrel 7 can withstand the pressure of the elastic element 11, and the outside is machined into a conical surface with a tapered angle. The angle of the conical surface can be adjusted according to the actual use needs, and no restrictions are made here. Specifically, the sliding mandrel 7 is provided with a sliding groove, which matches the slider 5, and the conical surface is set in the sliding groove.

[0031] See Figure 6 In the embodiment, there are usually multiple sliders 5. Specifically, there can be three sliders 5. The three sliders 5 are evenly distributed around the circumference. The inner side of each slider 5 is machined with an inclined surface that perfectly matches the conical surface of the sliding mandrel 7. The sliders 5 are installed in the slide groove and can slide along the slide groove.

[0032] See Figure 5 The inner support claw 4 is fixedly installed on the outer end of the slider 5 by the second bolt 14, and its outer contour shape is adapted to the inner wall shape of the workpiece to be processed.

[0033] See Figure 7 In this embodiment, the grease nipple 13 on the cover plate 6 is used to periodically inject grease into the sliding mandrel 7, slider 5, and other moving parts to ensure long-term flexibility and accuracy maintenance. The calibration component 10 is used to periodically inspect and calibrate the positioning accuracy of the fixture itself or when changing products.

[0034] When using this device, the worker first places the workpiece on the base plate 1, inserts the step positioning pin 2 into the existing positioning hole of the workpiece to achieve quick positioning, and then manually rotates the screw 8. The screw 8 is screwed downwards, compressing the elastic element 11. The elastic element 11 transmits the force to the sliding mandrel 7 to make it move downwards. During the downward movement, the conical surface of the sliding mandrel 7 pushes the inclined surface of the slider 5, so that the slider 5 moves radially outwards synchronously and evenly until the inner support claw 4 is in complete contact with the inner wall of the workpiece and applies a preload.

[0035] See Figure 9 At this point, the worker can rotate the workpiece to determine whether it is initially clamped and centered. Then, the pressure plate 15 is used to press the end face of the workpiece to complete axial fixation and anti-rotation. Finally, based on the measurement results of the test-cut parts, the rotation angle of the screw 8 can be adjusted again to control the magnitude of the radial tension force until the outer circle reference produced meets the accuracy requirements.

[0036] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A machine clamp for holding thin-walled parts to prevent deformation, characterized in that, It includes a base plate, device body, cover plate, sliding spindle, screw, elastic element, slider and inner support claw; The device body is fixedly mounted on the base plate, and the cover plate is fixedly mounted on the device body; The sliding mandrel is axially slidably disposed within the device body; The screw is threadedly connected to the cover plate, and the lower end of the screw acts on the top of the elastic element; the bottom of the elastic element acts on the upper end of the sliding spindle. The outer periphery of the sliding mandrel is provided with a conical surface, the slider cooperates with the conical surface and can slide radially; the inner support claw is installed on the slider.

2. The machining clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, The elastic element is sleeved on the lower end of the screw and accommodated in the spring mounting hole provided inside.

3. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 2, characterized in that, The elastic element is a cylindrical helical spring.

4. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, The slider has an inclined surface that matches the conical surface.

5. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, It also includes a stepped positioning pin for positioning the workpiece, the stepped positioning pin being fixedly mounted on the base plate.

6. A machining clamp for holding thin-walled parts and preventing deformation according to claim 1, characterized in that, It also includes a pressure plate, which is bolted to the end face of the workpiece to achieve axial positioning and anti-rotation of the workpiece.

7. A machining clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, The cover plate is also equipped with a grease fitting.

8. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, The number of sliders and inner support claws is multiple, and they are evenly distributed along the circumference of the device body.

9. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, The base plate is used to connect to the three-jaw chuck on the lathe.

10. A machine clamp for holding and preventing deformation of thin-walled parts according to claim 1, characterized in that, It also includes a calibration component used to calibrate the fixture.

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