Rapid positioning device for machining inner and outer key grooves
By combining the mandrel and the expansion sleeve, and utilizing the positioning strip of the expansion sleeve to engage with the keyway and the tightening of the nut, the problem of non-destructive clamping of workpieces with internal and external keyways by existing fixtures is solved, achieving a fast and non-destructive positioning effect, and improving machining accuracy and workpiece life.
Patent Information
- Application Number
- CN202422837377.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-20
AI Technical Summary
Existing fixtures are difficult to use for non-destructive clamping of workpieces with machined internal keyways, which can easily damage the workpiece and affect machining accuracy and lifespan.
The structure adopts a combination of mandrel and expansion sleeve. The positioning strip of the expansion sleeve is engaged with the keyway of the workpiece. The radial expansion of the expansion sleeve is achieved by tightening the nut. The positioning block of the mandrel is engaged with the slot of the expansion sleeve to achieve rapid positioning of the workpiece.
It enables rapid and non-destructive positioning of workpieces, improving machining accuracy and service life.
Smart Images

Figure CN223492098U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of positioning tooling technology, specifically a rapid positioning device for processing internal and external keyways. Background Technology
[0002] Workpiece (e.g.) Figure 2 As shown, the bushing with internal and external keyways is commonly used as an insulating sleeve in equipment. While ensuring insulation, it also bears the function of transmitting torque. If the symmetry deviation of the internal and external keyways is large, it will affect the transmission accuracy of the transmission shaft torque during equipment operation, affecting the transmission stability and shortening its service life. Therefore, it is necessary to accurately position the workpiece during processing. Existing fixtures are not convenient for non-destructive clamping of workpieces with internal keyways, and are prone to damaging the internal keyways of the workpiece. Therefore, we propose a rapid positioning device for processing internal and external keyways. Utility Model Content
[0003] The purpose of this invention is to provide a rapid positioning device for processing internal and external keyways, which solves the problems mentioned in the background art.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a quick positioning device for machining internal and external keyways, comprising a mandrel, an expansion sleeve, a nut, and a workpiece. The surface of the mandrel is provided with a threaded section that is threadedly connected to the nut. A positioning block is fixedly provided on the end surface of the mandrel away from the threaded section. A groove is provided on the outer circumferential surface of the expansion sleeve that engages with the positioning block. A keyway is provided in the inner hole of the workpiece. A positioning strip is fixedly provided on the outer circumferential surface of the expansion sleeve that engages with the keyway.
[0005] Furthermore, the mandrel surface is provided with a conical surface, which is located between the threaded section and the positioning block, with the narrow end of the conical surface facing the threaded section.
[0006] Furthermore, the outer circumferential surface of the expansion sleeve has several openings, the length of which is three-quarters of the radial length of the expansion sleeve.
[0007] Furthermore, the openings are staggered on the outer circumferential surface of the expansion sleeve, and the openings are parallel to the positioning strips.
[0008] Furthermore, both ends of the mandrel are provided with machining positioning holes for clamping.
[0009] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0010] The technical solution of this application has evenly distributed openings at both ends of the expansion sleeve. The expansion sleeve expands radially by fitting the conical surface of the mandrel with the nut, which is used to clamp the workpiece. The positioning strip of the expansion sleeve is engaged with the keyway of the workpiece to achieve anti-movement assembly between the expansion sleeve and the workpiece. The mandrel is engaged with the expansion sleeve through the positioning block, which also achieves anti-movement assembly between the mandrel and the expansion sleeve. Thus, when the two ends of the mandrel are fixed, the workpiece can be quickly positioned, which facilitates the machining of the external keyway of the workpiece. Attached Figure Description
[0011] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0012] Figure 1 A schematic diagram of the assembly of a rapid positioning device for machining internal and external keyways and the workpiece.
[0013] Figure 2 This is a schematic diagram of the structure of the workpiece being processed;
[0014] Figure 3 This is a schematic diagram of the mandrel structure;
[0015] Figure 4 This is a schematic diagram of the expansion sleeve.
[0016] In the diagram: 1. Nut; 2. Mandrel; 201. Threaded section; 202. Conical surface; 203. Locating hole; 3. Expansion sleeve; 301. Locating strip; 302. Opening slit; 303. Slot; 4. Locating block; 5. Workpiece to be machined; 501. Keyway; 502. External keyway to be machined. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0018] Example 1, such as Figure 1-4As shown, this utility model provides a technical solution: a rapid positioning device for machining internal and external keyways, including a mandrel 2, an expansion sleeve 3, a nut 1, and a workpiece 5. The mandrel 2 has a threaded section 201 that is threadedly connected to the nut 1. A positioning block 4 is fixedly mounted on the end of the mandrel 2 away from the threaded section 201. The outer circumferential surface of the expansion sleeve 3 has a groove 303 that engages with the positioning block 4. The inner hole of the workpiece 5 has a keyway 501. A positioning strip 301 that engages with the keyway 501 is fixedly mounted on the outer circumferential surface of the expansion sleeve 3. A conical surface 202 is provided on the surface of the mandrel 2, located between the threaded section 201 and the positioning block 4. The narrow end of the conical surface 202 faces the threaded section 201. The positioning block 4 can also indicate the position of the external keyway 502 (e.g., ...). Figure 1 (As shown).
[0019] In a specific embodiment of this utility model, the inner diameter of the mandrel 2 is the same as the inner diameter of the expansion sleeve 3. The mandrel 2 is provided with a micro conical surface 202. When the expansion sleeve 3 is completely fitted onto the conical surface 202, the expansion sleeve 3 will expand along the opening slit 302, thereby tightly fitting the inner cavity of the workpiece 5. The expansion sleeve 3 is made of spring steel, which is not easily deformed after repeated use. Both ends of the expansion sleeve 3 are provided with guide angles, which are convenient for installation and are not easy to damage the workpiece.
[0020] In the preferred technical solution, a number of openings 302 are provided on the outer circumferential surface of the expansion sleeve 3. The length of the openings 302 is three-quarters of the radial length of the expansion sleeve 3. The openings 302 are staggered on the outer circumferential surface of the expansion sleeve 3. The openings 302 are parallel to the positioning strips 301. The staggered arrangement of the openings 302 allows the expansion sleeve 3 to expand at both the left and right ends, achieving a uniform tightening effect.
[0021] In the preferred technical solution, both ends of the mandrel 2 are provided with machining positioning holes 203 for clamping, which facilitates clamping and positioning of both ends of the mandrel 2 using a fixture.
[0022] Working principle: The expansion sleeve 3 is fitted into the inner hole of the workpiece 5. The positioning strip 301 of the expansion sleeve 3 is engaged with the keyway 501 of the workpiece. Then, the mandrel 2 is inserted from the right side of the expansion sleeve 3. The nut 1 is then screwed into the threaded section 201. By rotating the nut 1, the expansion sleeve 3 is pushed to move along the conical surface 202. When the expansion sleeve 3 is fully fitted onto the conical surface 202, the expansion sleeve 3 will expand along the opening slit 302, thus tightly fitting the inner cavity of the workpiece 5. The positioning strip of the expansion sleeve is engaged with the keyway 501 of the workpiece, realizing the anti-movement assembly between the expansion sleeve and the workpiece. The mandrel 2 is engaged with the expansion sleeve through the positioning block 4 into the slot 303 of the expansion sleeve, realizing the anti-movement assembly between the mandrel 2 and the expansion sleeve. When the two ends of the mandrel are fixed, the workpiece can be quickly positioned, thus facilitating the machining of the external keyway 502.
Claims
1. A rapid positioning device for machining internal and external keyways, characterized in that: The assembly includes a mandrel (2), an expansion sleeve (3), a nut (1), and a workpiece (5). The mandrel (2) has a threaded section (201) that is threaded to the nut (1). A positioning block (4) is fixedly provided on the end of the mandrel (2) away from the threaded section (201). The outer circumferential surface of the expansion sleeve (3) has a groove (303) that engages with the positioning block (4). The inner hole of the workpiece (5) has a keyway (501). The outer circumferential surface of the expansion sleeve (3) has a positioning strip (301) that engages with the keyway (501).
2. The rapid positioning device for machining internal and external keyways according to claim 1, characterized in that: The mandrel (2) has a tapered surface (202) on its surface. The tapered surface (202) is located between the threaded section (201) and the positioning block (4). The narrow end of the tapered surface (202) faces the threaded section (201).
3. The rapid positioning device for machining internal and external keyways according to claim 2, characterized in that: The outer circumferential surface of the expansion sleeve (3) has several openings (302), and the length of the openings (302) is three-quarters of the radial length of the expansion sleeve (3).
4. The rapid positioning device for machining internal and external keyways according to claim 3, characterized in that: The openings (302) are staggered on the outer circumferential surface of the expansion sleeve (3), and the openings (302) are parallel to the positioning strips (301).
5. The rapid positioning device for machining internal and external keyways according to claim 1, characterized in that: Both ends of the mandrel (2) are provided with machining positioning holes (203) for clamping.
Citation Information
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