A flexible positioning clamp for thread dies for machining threads on elongated shaft parts

Abstract

A flexible positioning clamp for thread processing of an elongated shaft part is composed of a bushing, a clamp body and a guide rod, the bushing is provided with a bushing limiting key, a bushing cooling liquid through hole and a bushing transition hole, the clamp body is provided with a limiting screw, a limiting screw guide slot, a bushing limiting slot, an adjusting screw hole, a locking screw hole, a die assembly hole, a clamp cooling liquid through hole, a clamp guide hole and a die assembly hole, the adjusting screw hole is assembled with an adjusting screw, the locking screw hole is assembled with a locking screw, the guide rod is provided with a guide rod limiting screw hole and a guide rod transition hole, the bushing is assembled into the clamp body after the bushing limiting key is matched with the bushing limiting slot, one end of the guide rod is fixed on a lathe tool rest, the other end of the guide rod is assembled into the clamp body through the clamp guide hole, the limiting screw is matched with the guide rod limiting screw hole after passing through the limiting screw guide slot, so that the clamp body can only make axial reciprocating linear motion along the limiting screw guide slot through the limiting screw.

Description

Technical Field

[0001] This invention relates to a flexible positioning fixture for dies, and more particularly to a flexible positioning fixture for dies used in machining threads on slender shaft parts. Background Technology

[0002] The contactor core rod has a large length-to-diameter ratio and weak overall rigidity. When using traditional dies and die holders to perform external threading on the slender shaft, the ordinary die holders do not have a dedicated positioning support structure. The core rod is prone to radial runout and bending deformation under the cutting force, which ultimately leads to quality problems such as skewed thread profile, non-concentricity, and non-compliant pitch diameter, resulting in a high scrap rate.

[0003] Traditional die holders cannot effectively cool and lubricate the dies during threading, and uneven force during manual operation can easily cause the dies to jam or break, resulting in a short service life. Furthermore, if the threading diameter needs to be adjusted after the die is installed in the die holder, the die must be removed and the adjusting thread turned, which is cumbersome, time-consuming, and labor-intensive.

[0004] There is an urgent need to design an integrated coaxial reference structure die flexible positioning fixture based on the part structure. This fixture is positioned on the CNC lathe tool post or the tailstock of a conventional lathe. It uses a flexible support structure to prevent the part from deforming. It also features quick assembly and disassembly, quick adjustment of the die thread pitch diameter, the ability to add coolant during operation, and compatibility with multiple specifications. Summary of the Invention

[0005] The present invention aims to solve the technical problem of designing an integrated coaxial reference structure die flexible positioning fixture based on the part structure. The fixture is positioned on the CNC lathe tool post or the tailstock of a conventional lathe. It uses a flexible support structure to prevent part deformation and has the technical characteristics of quick assembly and disassembly, quick adjustment of the die thread pitch diameter, coolant addition during operation, and multi-specification compatibility.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A flexible positioning fixture for machining threads on slender shaft parts consists of three parts: a bushing, a fixture body, and a guide rod. The bushing is provided with a bushing limit key, a bushing coolant passage hole and a bushing transition hole; The fixture body is provided with a limit screw, a limit screw guide groove, a bushing limit groove, an adjusting threaded hole, a locking threaded hole, a die assembly hole, a fixture coolant water passage hole, a fixture guide hole, and a die assembly hole; the adjusting threaded hole is equipped with an adjusting screw; the locking threaded hole is equipped with a locking screw; The guide rod is provided with a guide rod limiting screw hole and a guide rod transition hole; The bushing is installed into the fixture after it is engaged with the bushing limiting groove via the bushing limiting key: One end of the guide rod is fixed to the lathe tool post, and the other end of the guide rod is inserted into the fixture body through the fixture guide hole. The limit screw is engaged with the limit screw hole of the guide rod after passing through the limit screw guide groove, so that the fixture body can only make axial reciprocating linear motion along the limit screw guide groove through the limit screw.

[0007] The beneficial effects of adopting the above technical solution are: This invention solves the problems of poor thread size and coaxiality qualification rate in the threading process of slender shaft parts with large length-to-diameter ratio by applying an integrated coaxial reference structure die positioning fixture design. It improves the service life of dies and achieves the effect of one set of fixtures being able to adapt to multiple models of dies. It has high application value. Attached Figure Description

[0008] Figure 1 It is a commonly used die structure.

[0009] Figure 2 This is an exploded view of the front structure of the clamping device of the present invention.

[0010] Figure 3 This is a schematic diagram of the reverse side structure of the fixture of the present invention.

[0011] Figure 4 This is a schematic diagram of the assembly structure of the clamping device of the present invention.

[0012] Figure 5 This is a front view of the lathe clamping effect of the die positioning fixture of the present invention.

[0013] Figure 6 for Figure 5 Rear view.

[0014] Figure 7 This is a partial view of the fixture positioning of the present invention.

[0015] In the diagram: 1-locking screw, 2-adjusting screw, 3-limit screw, 4-limit screw guide groove, 5-bulb limit groove, 6-positioning chuck, 7-bulb, 8-bulb limit key, 9-bulb coolant passage hole, 10-bulb transition hole, 11-adjusting threaded hole, 12-locking threaded hole, 13-die assembly hole, 14-guide rod transition hole, 15-guide rod limit screw hole, guide rod 16, 17-clamp coolant passage hole, 18-clamp guide hole, 19-die assembly hole, 20-clamp body. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0017] Based on the part structure, this invention designs an integrated coaxial reference structure die flexible positioning fixture. The fixture is positioned on the CNC lathe tool post or the tailstock of a conventional lathe. It uses a flexible support structure to prevent part deformation and features quick assembly and disassembly, quick adjustment of the die thread pitch diameter, coolant addition during operation, and compatibility with multiple specifications.

[0018] Fixture Composition: Bushing 7 is inserted into the fixture body after engaging with limit key 8 and limit groove 5. Then, die is inserted into the fixture body through assembly hole 13. Locking screw 1 and adjusting screw 2 are respectively inserted into the fixture body through threaded holes 12 and 11. Figure 1 The middle die limit hole and adjustment groove cooperate to achieve the positioning and locking of the die. The square end of the positioning chuck 6 is fixed on the lathe tool post, and the other end guide rod 16 is inserted into the fixture body through the fixture guide hole 18. The limit screw 3 cooperates with the screw hole 15 after passing through the guide groove 4, so that the fixture body can only make axial reciprocating linear movement along the guide groove 4 through the limit screw 3 (one end of the guide rod 16 has been fixed on the lathe tool post).

[0019] Fixture function description; Adjustable locking structure with center diameter; like Figure 7 As shown, turn the adjusting screw, and move it through the conical surface at the tip of the screw. Figure 1 The radial displacement within the adjusting groove of the die causes a slight change in the groove width, thereby achieving the effect of fine-tuning the thread pitch diameter.

[0020] The integrated coaxial reference structure design effectively prevents parts from deforming. like Figure 7 As shown, during the threading process of a certain product's core rod component, the distal thread passes through... Figure 4 The intermediate bushing transition hole 10 and the guide rod transition hole 14 enable the parts to avoid each other, while the mandrel, die, and guide hole of the clamping body provide multi-point flexible support, forming an auxiliary support for the mandrel throughout the operation, thereby offsetting the radial cutting force. From the design structure, this completely solves the problems of bending deformation of the thread rod and excessive radial runout (coaxiality) during the threading process of slender shaft parts.

[0021] Cooling during the operation; Insert the end of the coolant injection pipe into the coolant passage hole 17 of the clamp body. The coolant flows into the gap between the die and the bushing through the coolant passage hole 17 and the bushing coolant passage hole 9, and finally flows out from the chip removal hole at the die 3. This achieves cooling and lubrication of the die and parts during the threading process, and improves the service life of the die.

[0022] Stable and efficient operation; The clamping and adjustment steps of the fixture are simple. During the threading process, the workpiece rotates at a low speed with the lathe spindle, and the die moves at a low speed along the X-axis of the lathe with the fixture. The stroke of the fixture is limited by the limiting screw, so it will not disengage from the guide rod. At the same time, the rigid positioning base and the rotating handle of the fixture cooperate to make the die evenly stressed during the threading process, avoiding the die jamming and tooth breakage, and improving the service life of the die.

[0023] The versatility of clamping devices Common thread specifications for parts include M2, M2.5, M3, M4, M5, M6, and M8. Among these, the standard outer diameter of the M2, M2.5, M3, and M4 dies is φ20. Figure 2 and Figure 3 The 13-hole adapter is compatible with M5, M6, and M8 dies, whose standard outer diameter is φ25. Figure 2 and Figure 3 Middle assembly hole 19 adapter (only need to replace) Figure 2 (The middle bushing 7 is sufficient), thus achieving the effect of assembling multiple models and specifications of dies in one fixture.

Claims

1. A flexible positioning fixture for machining threads on slender shaft parts, characterized in that: It consists of three parts: bushing (7), clamp body (20), and guide rod (16); The bushing (7) is provided with a bushing limit key (8), a bushing coolant passage hole (9) and a bushing transition hole (10). The fixture body (20) is provided with a limiting screw (3), a limiting screw guide groove (4), a bushing limiting groove (5), an adjusting threaded hole (11), a locking threaded hole (12), a die assembly hole (13), a fixture coolant passage hole (17), a fixture guide hole (18), and a die assembly hole (19); the adjusting threaded hole (11) is equipped with an adjusting screw (2); the locking threaded hole (12) is equipped with a locking screw (1); The guide rod (16) is provided with a guide rod limiting screw hole (15) and a guide rod transition hole (14). The bushing (7) is installed into the clamp body (20) after it is engaged with the bushing limiting groove (5) via the bushing limiting key (8): One end of the guide rod (16) is fixed on the lathe tool post, and the other end of the guide rod (16) is inserted into the fixture body (20) through the fixture guide hole (18). The limiting screw (3) passes through the limiting screw guide groove (4) and then engages with the guide rod limiting screw hole (15), so that the fixture body (20) can only make axial reciprocating linear motion along the limiting screw guide groove (4) through the limiting screw (3).

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