High-precision dumbbell-shaped slender link turning clamp

Abstract

This invention provides a high-precision dumbbell-shaped slender connecting rod turning fixture, comprising a fixture body, a clamp, and a cap. The clamp is a separate structure, fitted onto the thin rod in the middle of the part, and connected to the fixture body. The cap is a circular groove with a through hole at the bottom, threadedly connected to the fixture body, with the clamp located inside the cap. The first end of the part protrudes from the through hole of the cap, and the other end of the fixture body is connected to the machine tool spindle via a three-jaw chuck. This invention features a compact structure and small size, high repeatability, convenient clamping, and simple operation, improving the machining efficiency and accuracy of parts while ensuring consistent quality. It can achieve high-precision dimensional machining and control of irregularly shaped long rods, and its versatility can be enhanced by changing the clamp specifications.

Description

Technical Field

[0001] This invention belongs to the field of fixture technology, and specifically relates to a turning fixture for machining slender rods that are thin in the middle, thick at both ends, and have high-precision dimensional requirements on the end faces. Background Technology

[0002] Application No. 201720165864.8 discloses a slender shaft clamping structure and fixture, proposing a high-precision slender shaft machining clamping fixture, mainly used for slender shaft parts with uniform outer diameters. During machining, the part needs to be inserted into the fixture's receiving hole, with the exposed portion of the fixture protruding. A tailstock is used to clamp the part, improving the stability of the exposed portion during turning rotation. This fixture is not suitable for slender rods with inconsistent dimensions, and due to the tailstock clamping method, it cannot be used to machine structures such as high-precision holes on the product's end face. Currently, for high-precision turning operations of parts with a thin middle and thick ends, a common and simple clamping method is used, employing a back cap and a simple split-type ring washer. This clamping and positioning is inconvenient and inaccurate, with poor clamping stability and unreliable clamping, easily damaging the part. Furthermore, low machining accuracy leads to low production efficiency, low part yield, and increased production costs. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a high-precision dumbbell-shaped slender connecting rod turning fixture, which solves the problem that ordinary clamping fixtures cannot clamp the part or have poor clamping stability, thus affecting the machining accuracy.

[0004] The technical solution adopted in this invention is: a high-precision dumbbell-shaped slender connecting rod turning fixture, including a fixture body, a clamp, and a cap. The clamp is a split structure, which is fitted onto the thin rod in the middle of the part and is sleeved with the fixture body. The cap is a circular groove with a through hole at the bottom, and is threadedly connected to the fixture body. The clamp is located inside the cap. The first end of the part protrudes from the through hole of the cap, and the other end of the fixture body is connected to the machine tool spindle via a three-jaw chuck.

[0005] Preferably, it also includes a gasket, which is installed between the clamp and the cap.

[0006] Preferably, the clamp is an assembly of rings with unequal diameters. From back to front, the clamp consists of a tapered section, a large-diameter section, and a small-diameter section. The clamp has a through hole machined axially, and the diameter of the hole matches the outer diameter of the thin rod in the middle of the part. A shim is installed at the small-diameter section.

[0007] Preferably, the clamp body is a ring of unequal diameter with a through hole machined inside. The first half of the through hole is a tapered hole, the shape of which matches the tapered section of the clamp. The second half of the through hole is a round hole with a diameter greater than the maximum outer diameter of the second end of the part. The first section of the clamp body has a smaller diameter and a first external thread machined on its outer wall. The middle section has a larger diameter and a second external thread machined on its outer wall. The tail section is a connecting section adapted to the three-jaw chuck of the machine tool. The clamp body and the cap are threadedly connected at the second external thread.

[0008] Preferably, the clamp is machined and then cut into two identical parts along the axial direction, with a cutting gap greater than 0.5mm and less than 1mm, to ensure that the inner hole of the clamp can fit tightly with the outer diameter of the part's thin rod clamping part after cutting.

[0009] Preferably, a stress relief ring is threadedly connected at the first external thread. The stress relief ring is a circular ring with an internal thread. The stress relief ring can move back and forth around the first external thread along the axial direction of the clamp body. The outer wall of the stress relief ring is machined with a groove that facilitates twisting. It is convenient to move the stress relief ring forward by using a tool to align with the groove or by manually rotating it so that it pushes against the end face of the large diameter section of the clamp, thereby pushing the clamp and parts out of the clamp body for easy disassembly.

[0010] Preferably, the length of the tapered section of the clamp is greater than the length of the tapered hole of the clamp body, so that when the clamp is fitted onto the clamp body, there is a gap between the front end face of the clamp body and the rear end face of the large-diameter section of the clamp, so as to ensure that the clamping force is applied to the outer diameter of the part during clamping.

[0011] Preferably, the gap length is less than the length of the unloading ring, so that the unloading ring can push out of the clamp.

[0012] Preferably, the diameter of the circular hole is greater than the maximum outer diameter of the second end and the maximum outer diameter of the first end of the part, so as to realize the machining of both ends of the part.

[0013] The beneficial effects of this invention are: the invention has a compact structure and small size, and has the advantages of high repeatability, convenient clamping, and simple operation. It improves the processing efficiency and accuracy of parts, and ensures the consistency of their quality. It can realize high-precision dimensional processing and control of irregular long rods, and its versatility can be enhanced by changing the specifications of the clamps. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a high-precision dumbbell-shaped slender connecting rod turning fixture.

[0015] Figure 2 This is a schematic diagram of the cross-sectional structure of the cap.

[0016] Figure 3 This is a schematic diagram of the cap's structure.

[0017] Figure 4This is a schematic diagram of the cross-sectional structure of the clamp.

[0018] Figure 5 This is a schematic diagram of the clamp structure.

[0019] Figure 6 This is a schematic diagram of the cross-sectional structure of the stress relief ring.

[0020] Figure 7 This is a schematic diagram of the unloading ring.

[0021] Figure 8 This is a schematic diagram of the cross-sectional structure of the clamping body.

[0022] Figure 9 This is a schematic diagram of the cross-sectional structure of the part.

[0023] Reference numerals: 1-cap, 2-shield, 3-clamp, 4-unloading ring, 5-clamp body, 6-part, 301-small diameter section, 302-large diameter section, 303-tapered section, 501-through hole, 502-first external thread, 503-second external thread, 601-first end, 602-second end. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. The term "front side" as used herein refers to the direction of the processing end, i.e. Figure 1 The right side and rear side refer to the direction of connection with the machine tool. Figure 1 Left side.

[0025] like Figure 9 As shown, part 6 is a slender rod structure with larger diameters at both ends and a uniform diameter in the middle. The left end of the figure is the second end 602, and the right end of the figure is the first end 601. This embodiment takes the processing of the first end 601 as an example.

[0026] like Figure 1 As shown, a high-precision dumbbell-shaped slender connecting rod turning fixture includes a fixture body 5, a clamp 3, a washer 2, and a cap 1. The clamp 3 is a split structure, fitted onto the thin rod in the middle of part 6. The front end face of the clamp 3 is fitted and positioned against the first end face 601 of part 6, facilitating length control during part 6 machining. The clamp 3 is sleeved onto the fixture body 5, as shown... Figure 2 and Figure 3As shown, the cap 1 is a circular groove with a through hole at the bottom. The cap 1 is threadedly connected to the fixture body 5. The clamp 3 is located inside the cap groove. The gasket 2 is installed between the clamp 3 and the cap 1. The inner diameter of the gasket 2 is smaller than the diameter of the through hole of the cap 1. The diameter of the through hole is larger than the maximum outer diameter of the first end 601 and the second end 602 of the part 6. The first end 601 of the part 6 protrudes from the through hole of the cap 1 for easy processing. The other end of the fixture body 5 is connected to the machine tool spindle via a three-jaw chuck.

[0027] like Figure 4 and Figure 5 As shown, clamp 3 is an assembly of rings with unequal diameters. From back to front, clamp 3 consists of a tapered section 303, a large-diameter section 302, and a small-diameter section 301. Clamp 3 has a through-hole machined axially, the diameter of which matches the outer diameter of the thin rod in the middle of part 6. A shim 2 is installed at the small-diameter section 301, and the outer diameter of shim 2 is equal to the outer diameter of the small-diameter section 301. Clamp 3 is machined and then cut axially into two symmetrical parts with a cut gap greater than 0.5mm and less than 1mm to ensure that the two semicircular holes of clamp 3 can fit tightly with the outer diameter of the clamping part of the thin rod in part 6 after cutting.

[0028] like Figure 8 As shown, the fixture body 5 is an annular body with unequal diameters and a through hole 501 machined inside. The first half of the through hole 501 is a tapered hole, the shape of which matches the shape of the tapered section 303 of the clamp 3. The second half of the through hole 501 is a circular hole, the diameter of which is larger than the maximum outer diameter of the second end 602 of part 6 or larger than the maximum outer diameter of the first end 601 and the second end 602. The first section of the fixture body 5 has a smaller diameter and a first external thread 502 machined on its outer wall, the middle section has a larger diameter and a second external thread 503 machined on its outer wall, and the tail section is a connecting section adapted to the three-jaw chuck of the machine tool. The fixture body 5 and the cap 1 are threadedly connected at the second external thread 503. A stress relief ring 4 is threadedly connected at the first external thread 502. Figure 6 and Figure 7 As shown, the unloading ring 4 is a circular ring with internal threads. The unloading ring 4 can move back and forth along the clamp body 5 axially around the first external thread 502. The outer wall of the unloading ring 4 is machined with a groove that facilitates twisting. It is convenient to move the unloading ring 4 forward by using a tool to connect the groove or by manually rotating it so that it hits the end face of the large diameter section 302 of the clamp 3, thereby pushing the clamp 3 and the part 6 out of the clamp body 5.

[0029] The length of the tapered section 303 of the clamp 3 is greater than the length of the tapered hole of the clamp body 5, so that when the clamp 3 is fitted onto the clamp body 5, there is a gap between the front end face of the clamp body 5 and the rear end face of the large diameter section 302 of the clamp 3, so as to ensure that the clamping force is applied to the outer diameter of the part 6 during clamping. The gap length is less than the length of the unloading ring 4, so that the unloading ring 4 can push out the clamp.

[0030] The working principle and usage process of this invention are as follows: First, connect the clamp body 5 to the machine tool spindle using a three-jaw chuck. Then, combine the clamp 3 with the thin rod of part 6, ensuring the end face of the first end 601 aligns with the small-diameter section 301 of the clamp 3. The clamp 3 has a through-hole machined axially, the diameter of which matches the outer diameter of the thin rod in the middle of part 6. Position the product against the front end face of the small-diameter section 301. Mount the assembled product onto the clamp body 5, which already has the unloading ring 4 installed, inserting the tapered section 303 into the tapered hole of the through hole 501. Then, install the gasket 2 on the small-diameter section 301 of the clamp 3. Finally, thread the cap 1 to the second external thread 503 of the clamp body 5, using the cap 1 to fix part 6 onto the clamp body 5. This completes the clamping and installation of part 6 and the machine tool spindle. After the part 6 and the clamp are installed, the clamping and installation process is as follows: Figure 1 As shown. After part 6 is machined, remove the cap 1. The clamp 3 and the fixture body 5 fit tightly. Use the relief ring 4 to move forward and push the end face of the clamp 3 to remove the clamp 3 along with part 6 from the fixture body 5, completing one loading and unloading of part 6. In actual use, the dimensions of the clamp 3 and the fixture body 5 can be adjusted according to the outer diameter of the product to be machined to enhance the versatility of the fixture and improve work efficiency.

[0031] The above describes specific embodiments of the present invention and the technical principles employed. Any modifications or equivalent transformations based on the technical solutions of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision dumbbell-shaped slender connecting rod turning fixture, characterized in that: The fixture includes a clamp body, a clamp, and a cap. The clamp is a separate structure, fitted onto the thin rod in the middle of the part, and connected to the clamp body. The cap is a circular groove with a through hole at the bottom, threadedly connected to the clamp body. The clamp is located inside the cap. The first end of the part protrudes from the through hole of the cap. The other end of the clamp body is connected to the machine tool spindle via a three-jaw chuck. The clamp is an assembly of unequal-diameter rings, consisting of a tapered section, a large-diameter section, and a small-diameter section from back to front. A through circular hole is machined axially on the clamp, the diameter of which matches the outer diameter of the thin rod in the middle of the part. A shim is installed at the small-diameter section. The clamp body is an unequal-diameter ring with a through hole machined inside. The first half of the through hole is a tapered hole, the shape of which matches the shape of the tapered section of the clamp. The second half of the through hole... The section is a circular hole with a diameter greater than the maximum outer diameter of the second end of the part. The first section of the clamp body has a smaller diameter and a first external thread machined on its outer wall. The middle section has a larger diameter and a second external thread machined on its outer wall. The tail section is a connecting section adapted to the three-jaw chuck of the machine tool. The clamp body and the cap are threadedly connected at the second external thread. A stress relief ring is threadedly connected at the first external thread. The stress relief ring is a circular ring with an internal thread. The stress relief ring can move back and forth along the axial direction of the clamp body around the first external thread. The outer wall of the stress relief ring is machined with a groove to facilitate torsion. The length of the tapered section of the clamp is greater than the length of the tapered hole of the clamp body, so that when the clamp is fitted onto the clamp body, there is a gap between the front end face of the clamp body and the rear end face of the large-diameter section of the clamp. The length of the gap is less than the length of the stress relief ring.

2. The high-precision dumbbell-shaped slender connecting rod turning fixture according to claim 1, characterized in that: It also includes a gasket, which is installed between the clamp and the cap.

3. The high-precision dumbbell-shaped slender connecting rod turning fixture according to claim 1, characterized in that: The clamp is machined and then cut into two identical parts along the axial direction, with a cutting gap greater than 0.5 mm and less than 1 mm.

4. The high-precision dumbbell-shaped slender connecting rod turning fixture according to claim 1, characterized in that: The diameter of the circular hole is greater than the maximum outer diameter of the second end and the maximum outer diameter of the first end of the part.

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