Locking clamp for thin-wall slender rod type parts

Abstract

The invention relates to a thin-wall slender rod type part locking clamp, and belongs to the technical field of numerical control machine tool machining. The clamp comprises a clamp body, a gasket and a locking nut, clamping force borne by a part in the machining process is effectively dispersed and vibration and deformation of the part are limited through thread fit and the design of a limiting structure, and the clamp is particularly suitable for inner hole machining of thin-wall slender rod type parts with the length-diameter ratio larger than 10. The clamp is simple in structure and efficient in clamping, the quality of the machined surface can be remarkably improved, tool abrasion is reduced, and high practicability and economical efficiency are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of CNC machine tool processing, and in particular relates to a locking fixture for thin-walled slender rod parts with a hole length-to-diameter ratio greater than 10 and a wall thickness of about 3 mm. Background Art

[0002] In CNC lathe machining, machining the inner holes of thin-walled, slender rod-like parts presents significant technical difficulties. Due to the thin walls and large aspect ratio of the parts, traditional clamping methods (such as direct clamping with a three-jaw chuck) can easily lead to the following problems: 1. Concentrated clamping force: Parts deform due to excessive local force, affecting the roundness and coaxiality of the inner hole; 2. Cutting vibration: The tool is prone to chatter during deep hole processing, which causes vibration marks on the inner surface and reduces the surface roughness; 3. Short tool life: Vibration aggravates tool wear and increases processing costs.

[0003] The company was machining the inner hole of a thin-walled, slender rod-like component with a length-to-diameter ratio greater than 10, a typical deep-hole operation. During machining, the tool was prone to vibration, affecting the surface finish. Furthermore, the part had a wall thickness of only 3mm, and the original machining method, which employed soft three-jaw direct clamping, was prone to deformation and vibration during machining, further impacting the machining accuracy and surface finish. Therefore, a tooling system was required to limit part vibration during machining to improve machining quality and extend tool life. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a locking clamp for thin-walled, slender rod-type parts, which aims to disperse the clamping force on the parts during processing, reduce the vibration of the parts and thus improve the processing quality of the part surface. It solves the problem that vibration easily produces chatter marks and deformation on the part surface when operating on the inner hole of the part, and affects the processing accuracy and surface roughness of the inner hole surface.

[0005] The technical solution adopted by the present invention is: a locking fixture for thin-walled, slender rod-like parts, including a clamping body, a gasket, and a locking nut. The clamping body is a cylindrical structure of unequal diameters, including two front and rear sections, with the diameter of the front section being twice the diameter of the rear section. The clamping body and the locking nut are both machined with internal threaded holes, which are adapted to the external threads of the middle section of the part. The locking nut, gasket, and clamping body are threadedly connected to the middle section of the part in sequence. The locking nut, gasket, and clamping body are in close contact with the clamping part in sequence. The rear section of the clamping body is provided with a clamping structure adapted to the three-jaw chuck of a machine tool. The threads of the clamping body and the locking nut cooperate to form an axial limit for the part. The gasket is located between the locking nut and the clamping body, further limiting the radial freedom of the part.

[0006] Preferably, the locking nut is located at the center of the length direction of the part, the outer diameter of the locking nut is consistent with the diameter of the front section of the clamp body, the thread accuracy of the locking nut is consistent with the external thread of the part, and a gap-free fit is formed after tightening to prevent loosening during use.

[0007] Preferably, the gasket is made of brass material and has a thickness of not less than 3 mm. The outer diameter of the gasket is consistent with the diameter of the front section of the clamp body and is used to buffer vibrations during processing.

[0008] Preferably, the length of the clamp body is not less than one fifth of the length of the part, and the clamp body is made of a metal material with high hardness and rigidity to disperse the clamping force and buffer vibration during processing.

[0009] The beneficial effects of the present invention are: the present invention has a simple structure, is easy to clamp, and simplifies the fixture structure. The tooling of the present invention disperses the clamping force and avoids the risk of deformation during clamping. The tooling limits the vibration of the parts through the combined use of the locking nut and the gasket, weakening the influence of vibration on the surface roughness and tool life during the processing. The tooling limits the freedom of the parts during the processing and reduces the cutting vibration of the parts through the cooperation of three simple components, thereby making the processing quality of the parts only related to the tangential force of the processing tool, while improving the processing quality, it also saves production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the structure of a locking fixture for thin-walled, slender rod parts.

[0011] Figure 2 This is a schematic diagram of the specific structure of the clamp.

[0012] Figure 3 Schematic diagram of the gasket structure.

[0013] Figure 4 It is a structural diagram of the locking nut.

[0014] Figure numerals: 1-clamp body, 2-washer, 3-locking nut. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] like Figures 1 to 4The figure shows a locking fixture for thin-walled, slender rod-like parts, comprising a clamp body 1, a washer 2, and a locking nut 3. The clamp body 1 is a cylindrical structure of unequal diameter, consisting of two sections, front and rear, with the front section having a diameter twice that of the rear section. Both the clamp body 1 and the locking nut 3 are machined with internal threaded holes that mate with the external threads of the part's midsection. The locking nut 3, washer 2, and clamp body 1 are sequentially threaded into the part's midsection. The locking nut 3, washer 2, and clamp body 1 are sequentially in close contact with the part, and the rear section of the clamp body 1 is clamped by a three-jaw chuck. The threads of the clamp body 1 and the locking nut 3 cooperate to limit the axial position of the part. The washer 2, located between the locking nut 3 and the clamp body 1, further restricts the radial freedom of the part.

[0017] like Figure 4 As shown, the locking nut 3 is located at the center of the length direction of the part, and the outer diameter of the locking nut 3 is consistent with the diameter of the front section of the clamp body 1. The thread accuracy of the locking nut 3 is consistent with the external thread of the part. After tightening, a gap-free fit is formed to prevent loosening during use.

[0018] like Figure 3 As shown, the gasket 2 is made of brass material with a thickness of not less than 3 mm. The outer diameter of the gasket 2 is consistent with the diameter of the front section of the clamp body 1 and is used to buffer vibration during the processing.

[0019] like Figure 2 As shown, the length of the clamp body 1 is not less than one-fifth of the length of the part. The clamp body 1 is made of a metal material with high hardness and rigidity, which disperses the clamping force and buffers vibration during processing.

[0020] The working principle and usage process of the present invention are as follows: When using this clamp tooling, first assemble the locking nut 3 on the outer surface of the middle section of the part through the thread on the outer surface of the part, then put the gasket 2 on the part and place it in front of the locking nut 3, and then screw the part into the clamp body 1 until the locking nut, gasket and clamp body are tightly fitted, and finally use a three-jaw chuck to clamp the clamp body 1, and then the part is processed.

[0021] This fixture has completed multiple batches of trial production in a workshop and has been successfully applied to the batch processing of thin-walled slender rod parts. The yield rate has increased from 75% to 98%, the inner hole roundness error is ≤0.02mm, the surface roughness is Ra0.6μm, and the tool life is extended by 40%.

[0022] The above are specific embodiments of the present invention and the technical principles used. Any modifications or equivalent transformations based on the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A locking fixture for thin-walled, slender rod parts, characterized by: It includes a clamping body, a gasket and a locking nut. The clamping body is a cylindrical structure of unequal diameters and includes two sections, front and rear sections, and the diameter of the front section is twice the diameter of the rear section. The clamping body and the locking nut are both processed with internal threaded holes, which are adapted to the external threads of the middle section of the part. The locking nut, gasket and clamping body are threadedly connected to the middle section of the part in sequence. The locking nut, gasket and clamping body are in close contact with the clamping part in sequence. The rear section of the clamping body is provided with a clamping structure adapted to the three-jaw chuck of the machine tool to ensure a firm connection between the fixture and the machine tool.

2. A locking fixture for thin-walled, slender rod parts according to claim 1, characterized in that: The locking nut is located at the center of the length direction of the part. The outer diameter of the locking nut is consistent with the diameter of the front section of the clamp. The thread accuracy of the locking nut is consistent with the external thread of the part. After tightening, a gap-free fit is formed. The locking nut is made of brass material and has a thickness of not less than 3 mm.

3. The locking fixture for thin-walled, slender rod parts according to claim 1, characterized in that: The gasket is made of brass material and has a thickness of no less than 3 mm. The outer diameter of the gasket is consistent with the diameter of the front section of the clamp body.

4. The locking fixture for thin-walled, slender rod parts according to claim 1, characterized in that: The length of the clamp body is not less than one fifth of the length of the part, and the clamp body is made of metal material.

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