Internal expansion type numerical control lathe clamp for thin-walled cylinder workpiece

Abstract

The invention discloses an internal expansion type numerical control lathe fixture for a thin-walled cylinder workpiece. The internal expansion type numerical control lathe fixture comprises a chuck body, a fixture body, a positioning cover, an expansion sleeve, a locking block and a locking wrench, the other end of the chuck body is connected with the clamp body; the positioning cover is connected with the clamp body, and the outer surface of the positioning cover makes contact with the outer surface of a workpiece to achieve workpiece positioning. The expansion sleeve is in conical fit with the clamp body, and the expansion sleeve expands to enable the outer surface of the expansion sleeve to make contact with a workpiece so as to abut against and clamp the workpiece; the locking block is connected with the expansion sleeve, the locking block is in threaded connection with the clamp body, and the expansion sleeve is controlled to be expanded and shrunk through rotation of the locking block; and the locking wrench is connected with the locking block. The expansion sleeve is matched with the conical surface of the clamp body, expansion of the expansion sleeve is controlled through threaded connection of the locking block, the thin-wall cylindrical workpiece is clamped by the expansion sleeve, the deformation of the part is reduced, the form and location tolerance of the part is guaranteed, the problem of machining vibration of the thin-wall workpiece is solved, and the machining efficiency and the machining quality of the part are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of fixtures, specifically to a CNC lathe fixture for a thin-walled cylindrical workpiece with internal expansion. Background Technology

[0002] In existing technologies, when machining thin-walled cylindrical parts with the inner circle as the reference, the positioning device generally uses rigid dimensions for positioning. For such devices, due to the poor rigidity of thin-walled parts causing vibration and deformation, and the clearance fit between the outer circle and the positioning inner hole, after the part is installed on the machine tool, firstly, the part cannot be installed in place if the deformation exceeds the tolerance of the positioning inner hole; secondly, the clearance between the outer circle and the positioning inner hole leads to coaxiality errors, resulting in out-of-tolerance form and position tolerances and unilateral issues after machining the inner shape, failing to meet the design requirements of the drawings. Summary of the Invention

[0003] When using existing three-jaw chucks to locate and clamp thin-walled cylindrical workpieces, the positioning dimensions of the positioning device are rigid dimensions. The coaxiality error between the outer circle of the part and the positioning inner hole, as well as the rigidity difference of the part itself, causes vibration when machining complex shapes in the middle, further amplifying the deformation of the part, exceeding the form and position tolerances, and increasing the wall thickness on one side. The purpose of this invention is to address the shortcomings of the above-mentioned prior art by providing an internal expansion type CNC lathe fixture for thin-walled cylindrical workpieces.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a CNC lathe fixture for thin-walled cylindrical workpieces with internal expansion, comprising a chuck body, a fixture body, a positioning cover, an expansion sleeve, a locking block, and a locking wrench; one end of the chuck body is connected to the machine tool spindle, and the other end is connected to the fixture body; the positioning cover is connected to the fixture body, and the outer surface of the positioning cover contacts the outer surface of the workpiece to achieve workpiece positioning; the expansion sleeve is conically fitted with the fixture body, and the expansion sleeve expands to make its outer surface contact the workpiece to clamp the workpiece; the locking block is connected to the expansion sleeve, and the locking block is threadedly connected to the fixture body, and the expansion and contraction of the expansion sleeve is controlled by rotating the locking block; the locking wrench is connected to the locking block.

[0005] As a further improvement to the above technical solution: The locking wrench is equipped with an auxiliary top plate, which engages with the workpiece in a conical shape.

[0006] The chuck body is provided with a first positioning hole and a directional groove, and is connected to the machine tool spindle through the first positioning hole and the directional groove.

[0007] The positioning cover has three evenly distributed second positioning holes, and the positioning cover is connected to the fixture body through the second positioning holes.

[0008] The expansion sleeve has a tapered hole inside and six small steps on its outer surface.

[0009] The locking block has an M48×1.5 external thread at one end of its outer surface and a hexagonal hole at the other end.

[0010] The runout of the outer cylindrical surface of the chuck body is less than 0.015 mm.

[0011] The coaxiality between the outer surface of the fixture body and the outer surface of the chuck body is no greater than 0.01 mm, and the cylindricity runout of the outer surface of the fixture body is no greater than 0.025 mm.

[0012] The coaxiality between the outer surface of the positioning cover and the fixture body is no greater than 0.01 mm.

[0013] The inner cone angle of the expansion sleeve is 120°, and the coaxiality between the expansion sleeve and the fixture body is no greater than 0.01mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The thin-walled cylindrical workpiece internal expansion CNC lathe fixture of the present invention has a simple structure and is easy to install and operate. The expansion sleeve and the outer surface of the fixture body are conical and fit together. The expansion of the expansion sleeve is controlled by the threaded connection of the locking block to achieve clamping of the thin-walled cylindrical workpiece. This reduces the deformation of the part, ensures the form and position tolerance of the part, solves the vibration problem in the machining of thin-walled parts, and greatly improves the machining efficiency and quality of the parts. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the chuck body structure of the present invention; Figure 3 This is a schematic diagram of the fixture body structure of the present invention; Figure 4 This is a schematic diagram of the positioning cover structure of the present invention; Figure 5 This is a schematic diagram of the expansion sleeve structure of the present invention; Figure 6 This is a schematic diagram of the locking block structure of the present invention; Figure 7 This is a schematic diagram of the locking auxiliary top plate and locking wrench structure of the present invention.

[0016] Reference numerals in the attached drawings: 1. Chuck body; 2. Fixture body; 3. Positioning cover; 4. Expansion sleeve; 5. Locking block; 6. Locking wrench; 7. Auxiliary top plate; 8. Workpiece. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or position based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figures 1 to 7 As shown, the thin-walled cylindrical workpiece internal expansion CNC lathe fixture of this embodiment includes a chuck body 1, a fixture body 2, a positioning cover 3, an expansion sleeve 4, a locking block 5, and a locking wrench 6; one end of the chuck body 1 is connected to the machine tool spindle, and the other end is connected to the fixture body 2; the positioning cover 3 is connected to the fixture body 2, and the outer surface of the positioning cover 3 contacts the outer surface of the workpiece 8 to achieve workpiece 8 positioning; the expansion sleeve 4 is conically fitted with the fixture body 2, and the expansion sleeve 4 expands so that its outer surface contacts the workpiece 8 to clamp the workpiece 8; the locking block 5 is connected to the expansion sleeve 4, and the locking block 5 is threadedly connected to the fixture body 2, and the expansion and contraction of the expansion sleeve 4 is controlled by rotating the locking block 5 (the expansion sleeve 4 is a rubber-coated expansion sleeve or a split expansion sleeve); the locking wrench 6 is connected to the locking block 5.

[0022] The locking wrench 6 is equipped with an auxiliary top plate 7, which is conically fitted with the workpiece 8. The auxiliary top plate 7 and the locking wrench 6 can be connected by threads, fixed connections, or other forms of connection, so that the locking wrench 6 can drive the auxiliary top plate 7 to press against the workpiece 8.

[0023] The chuck body 1 is provided with a first positioning hole and a directional groove, and is connected to the machine tool spindle through the first positioning hole and the directional groove.

[0024] The positioning cover 3 has three evenly distributed second positioning holes, and the positioning cover 3 is connected to the fixture body 2 through the second positioning holes.

[0025] The expansion sleeve 4 has a tapered hole inside, and six small steps on its outer surface. The small steps are used to increase the friction between the expansion sleeve and the inner hole of the workpiece.

[0026] The locking block 5 has an M48×1.5 external thread on one end of its outer surface and a hexagonal hole on the other end.

[0027] The runout of the outer cylindrical surface of the chuck body 1 is less than 0.015 mm.

[0028] The coaxiality between the outer surface of the fixture body 2 and the outer surface of the chuck body 1 is no greater than 0.01 mm, and the cylindricity runout of the outer surface of the fixture body 2 is no greater than 0.025 mm.

[0029] The coaxiality between the outer surface of the positioning cover 3 and the fixture body 2 is no greater than 0.01 mm.

[0030] The inner cone angle of the expansion sleeve 4 is 120°, and the coaxiality between the expansion sleeve 4 and the fixture body 2 is no greater than 0.01mm.

[0031] In use, the workpiece 8 is inserted into the expansion sleeve 4, with one end of the workpiece 8 abutting against the positioning cover 3. Then, the auxiliary top plate 7 is installed onto the locking wrench 6, and the locking wrench 6 is connected to the locking block 5, causing the locking block 5 to rotate. This moves the expansion sleeve 4. Due to the tapered fit between the expansion sleeve 4 and the fixture body 2, the expansion sleeve 4 expands, while the auxiliary top plate 7 presses against the other end of the workpiece 8, ensuring the workpiece is stably clamped. This solves the vibration problem in thin-walled part processing, greatly improving the processing efficiency and quality of the parts.

[0032] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics of the solutions is not described in detail here. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces, characterized in that, The chuck body (1), fixture body (2), positioning cover (3), expansion sleeve (4), locking block (5), and locking wrench (6) are included. One end of the chuck body (1) is connected to the machine tool spindle, and the other end is connected to the fixture body (2). The positioning cover (3) is connected to the fixture body (2), and the outer surface of the positioning cover (3) contacts the outer surface of the workpiece (8) to achieve workpiece (8) positioning. The expansion sleeve (4) is conically fitted with the fixture body (2), and the expansion sleeve (4) expands to make its outer surface contact the workpiece (8) to clamp the workpiece (8). The locking block (5) is connected to the expansion sleeve (4), and the locking block (5) is threadedly connected to the fixture body (2). The expansion and contraction of the expansion sleeve (4) are controlled by rotating the locking block (5). The locking wrench (6) is connected to the locking block (5).

2. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The locking wrench (6) is provided with an auxiliary top plate (7), which is in conical fit with the workpiece (8).

3. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The chuck body (1) is provided with a first positioning hole and a directional groove, and is connected to the machine tool spindle through the first positioning hole and the directional groove.

4. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The positioning cover (3) is provided with three evenly distributed second positioning holes, and the positioning cover (3) is connected to the fixture body (2) through the second positioning holes.

5. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The expansion sleeve (4) has a tapered hole inside, and the outer surface of the expansion sleeve (4) has 6 small steps.

6. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The locking block (5) has an M48×1.5 external thread on one end of its outer surface and a hexagonal hole on the other end.

7. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The runout of the outer cylindrical surface of the chuck body (1) is less than 0.015 mm.

8. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The coaxiality between the outer surface of the clamp body (2) and the outer surface of the chuck body (1) is no greater than 0.01 mm, and the cylindricity runout of the outer surface of the clamp body (2) is no greater than 0.025 mm.

9. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The coaxiality between the outer surface of the positioning cover (3) and the fixture body (2) is no greater than 0.01 mm.

10. The CNC lathe fixture for internal expansion of thin-walled cylindrical workpieces according to claim 1, characterized in that, The inner cone angle of the expansion sleeve (4) is 120°, and the coaxiality between the expansion sleeve (4) and the fixture body (2) is no greater than 0.01 mm.

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