CN218575019U - Soft mandrel clamp - Google Patents

Abstract

The utility model relates to an appurtenance of parts machining such as thin wall bush, axle sleeve specifically is a can improve soft dabber anchor clamps of thin wall bush, axle sleeve clamping precision. The fixture solves the technical problem that the fixture used in the processing of the existing thin-wall bushing and shaft sleeve parts influences the processing roundness of the workpiece and is inconvenient to disassemble after the coaxiality is processed. A soft mandrel clamp comprises a clamp body, an expansion sleeve, a gasket and a screw; the clamp body is of a shaft-shaped structure, a limiting circular truncated cone is arranged in the middle of the shaft-shaped structure, the clamp body located on one side of the limiting circular truncated cone is of a cylindrical structure, and the outer diameter of the clamp body located on the other side of the limiting circular truncated cone is of a conical structure which is shrunk outwards from the limiting circular truncated cone; the center of the end surface of the conical structure is provided with a screw hole matched with the screw along the axial direction; the section of the inner cavity of the expansion sleeve is in a cone shape matched with the cone-shaped structure; the side wall of the expansion sleeve is provided with a notch which penetrates through the front part and the rear part of the expansion sleeve; the center of the gasket is also provided with a screw hole; the conicity of the conical structure and the inner cavity of the expansion sleeve are 14 degrees.

Description

Soft mandrel clamp

Technical Field

The utility model relates to an appurtenance of parts machining such as thin wall bush, axle sleeve specifically is a can improve soft dabber anchor clamps of thin wall bush, axle sleeve clamping precision.

Background

The thin-wall bush and shaft sleeve parts have high precision and thin wall, the coaxiality precision of the inner circle and the outer circle is high, the roundness and cylindricity precision of the outer circle is high, and the universal method for processing the outer circle is to adopt a mandrel clamp for positioning and clamping. The rotation diameter of the bush and the shaft sleeve is phi 10 mm-phi 80mm generally, the wall thickness is 1 mm-5 mm generally, the form and position precision of the coaxiality of an inner circle and an outer circle, the roundness of the outer circle, the cylindricity precision and the like is up to 4 grades, and the size precision of the outer circle is up to IT 5-IT 6 grades.

At present, a mandrel clamp used comprises a quenched small-taper mandrel and a quenched elastic mandrel, the hardness of the two mandrels is high, and the two mandrels are also commonly called hard mandrels. Due to the structural defects of the two clamps, the two clamps have low precision and large deformation in use, and are easy to scratch the surface of a workpiece, the deformation of the processed workpiece is large, the design precision requirements of high-precision bushings and shaft sleeves (the design precision of the clamp is generally 1/5-1/3 of the precision of a product) are difficult to meet, and hidden dangers are brought to the stability and reliability of the processing quality of the product.

Specifically, the following defects exist in the method for processing high-precision thin-wall bushings and shaft sleeve parts by using a quenching small-taper mandrel and a quenching elastic mandrel for positioning and clamping at present.

1) The quenching elastic mandrel has the following defects: after an expansion sleeve equipped with the quenching elastic mandrel is quenched, the expansion sleeve is large in deformation and uneven in wall thickness, and meanwhile, the expansion sleeve is large in spring force, so that a thin-wall bushing is deformed when a high-precision thin-wall bushing part is clamped, an ellipse phenomenon occurs, and the roundness and the cylindricity of the outer circle of the machined bushing are poor.

2) The quenching small taper mandrel is used for positioning and clamping, a workpiece can be dismounted only by knocking with a red copper bar or a rubber hammer after processing, and the parts are deformed and easily damaged by knocking.

In order to improve the machining precision of the bushing and the shaft sleeve, ensure the quality stability and improve the machining efficiency, a new mandrel fixture is very necessary to be researched, and a soft mandrel fixture is actively popularized and designed.

Disclosure of Invention

The utility model discloses a solve anchor clamps that use in the processing of present thin wall bush, axle sleeve class part influence work piece processing circularity, processing and accomplish the inconvenient technical problem of back dismantlement, provide a soft dabber anchor clamps.

The utility model discloses an adopt following technical scheme to realize: a soft mandrel clamp comprises a clamp body, an expansion sleeve, a gasket and a screw; the clamp body is of a shaft-shaped structure, a limiting round table is arranged in the middle of the shaft-shaped structure, the clamp body located on one side of the limiting round table is of a cylindrical structure, and the outer diameter of the clamp body located on the other side of the limiting round table is of a conical structure which is shrunk outwards from the limiting round table; the center of the end surface of the conical structure is provided with a screw hole matched with the screw along the axial direction; the section of the inner cavity of the expansion sleeve is conical and is matched with the conical structure; the side wall of the expansion sleeve is provided with a notch which penetrates through the front part and the rear part of the expansion sleeve; the outer diameter of the gasket is larger than the inner diameter of the small-caliber side of the expansion sleeve and smaller than the outer diameter of the expansion sleeve, and a screw hole is formed in the center of the gasket; the conicity of the conical structure and the inner cavity of the expansion sleeve is 14 degrees.

The utility model discloses a anchor clamps body, the cover that rises, gasket and screw, the cover that rises during the use is in pressing from both sides specific toper structure one side, and the cover that rises is owing to open there is an incision, and the cover is after the anchor clamps body, and the gasket dress is in the one end in the cover outside that rises, then passes the screw in the screw twists behind the gasket presss from both sides specific screw, will rise the cover and withstand to the bush, the axle sleeve cover that will treat processing are in the cover outside that rises. The clamping force between the expansion sleeve and the bush to be processed is adjusted by rotating the screw, the dial indicator is used for detecting on the outer circle of the bush in real time, the dial indicator jump value is about 0.001-0.003 mm, namely the screw is clamped, and the screwing is stopped. The expansion sleeve is provided with a notch, so that the elasticity of the expansion sleeve is weakened, the phenomenon that the thin-wall bushing deforms to form an ellipse can be effectively avoided in the clamping process, and the roundness and the coaxiality of the excircle of the machined bushing are improved. Meanwhile, the expansion sleeve is provided with a notch, so that the expansion sleeve can be easily taken down after the workpiece is machined. The expansion sleeve and the clamp body adopt smaller taper angles, so that the positioning precision is ensured while the strength of the expansion sleeve is ensured, and the disassembly is more convenient.

In addition, the expansion sleeve is provided with a notch, a certain deformation allowance is reserved, the expansion sleeve has small shape change after being processed, and the phenomenon of uneven wall thickness is effectively reduced.

Through designing soft dabber anchor clamps, can realize following effect:

1) The cover that rises of soft dabber anchor clamps warp for a short time, and the work piece warp minimum behind the clamping work piece, does not fish tail work piece surface simultaneously.

2) The matching conical surface of the clamp body of the soft mandrel and the expansion sleeve is 14 degrees, the positioning precision is high, and the assembly and disassembly are convenient.

3) The soft core clamp can be used for processing parts such as bushings and shaft sleeves with higher precision. After machining, the coaxiality, cylindricity and roundness of the inner circle and the outer circle can reach 4 levels, and the machined part has small deformation and high machining efficiency.

Drawings

Fig. 1 is a schematic view of a thin-walled liner construction.

Fig. 2 is a schematic view of a soft mandrel fixture structure.

Fig. 3 is a schematic structural view of the clip body.

Fig. 4 is a schematic diagram of the expansion sleeve structure.

Fig. 5 is a side view of fig. 4.

1-a fixture body, 2-an expansion sleeve, 3-a gasket, 4-a screw, 11-a limiting circular table and 21-a notch.

Detailed Description

A liner in a certain series of products produced in batches by a company is shown in figure 1, the material of the part is precipitation hardening stainless steel 0Cr17Ni4Cu4Nb, the hardness requirement of the part is HRC 38-43, the structure is multi-step, has a radial annular groove and is thin-walled, the cylindricity of an inner hole is 0.011 mm, the cylindricity of an outer circle is 0.011 mm, the roundness is 0.011 mm, the coaxiality of the inner circle and the outer circle is phi 0.015 mm, the size precision of the outer circle is up to IT5, the size precision of an axial step of the liner step is IT6, and the surface roughness is 0.8um. After the existing quenching elastic mandrel is installed, the mandrel is not concentric with a machine tool main shaft, particularly, mohs taper holes and general faceplates are not designed in main shaft holes of all existing numerical control lathes and numerical control cylindrical grinding machines, the mandrel is installed on three claws or four claws, the coaxiality error of the mandrel and the machine tool main shaft cannot be eliminated after the mandrel is installed, and the coaxiality error of an outer circle to an inner hole is large after parts are machined. When the quenched small-taper mandrel is used, the dimensional accuracy, the roundness and the cylindricity of the reference inner hole are required to be high, otherwise, the state after clamping every time is inconsistent, and the end of the inner hole is greatly jumped by the end face after machining.

The bushing was finished using a newly designed soft mandrel fixture, the fixture construction is shown in fig. 2-5.

The utility model relates to a soft dabber anchor clamps. The soft mandrel clamp consists of a clamp body 1, an expansion sleeve 2, a gasket 3 and a screw 4, and is shown in figures 2-5.

1) The clamp body 1 is made of 40Cr, the heat treatment (hardening and tempering) hardness is HRC 32-HRC 38, the mechanical property is good, after the clamp is installed on a lathe (grinding) machine, the actual coaxiality error of the clamp and a main shaft of the lathe (grinding) machine is 0 by correcting the conical surface of the clamp body matched with the expansion sleeve, and the error caused by the fact that the clamp and a machine tool are not concentric is eliminated.

2) The material of the expansion sleeve 2 is brass H62 or other nonferrous metals and the like, the hardness of the material is lower than that of the workpiece material, the expansion sleeve has good mechanical property, the deformation of the expansion sleeve is small, the abrasion resistance of the expansion sleeve is high, the workpiece deformation is extremely small when the high-precision thin-wall bushing type part is clamped, and the workpiece is not easy to scratch.

3) The conical surface of the fixture body 1 and the matching conical surface of the expansion sleeve 2 are 14 degrees, the positioning precision is high, and the assembly and disassembly are convenient. The conical surface of the clamp body is processed according to the conical surface of the expansion sleeve in a matching way, the matching surface has high fitting degree, centering and no self-locking are realized, and the positioning precision is high, so that the fixed position is reliable and the workpiece is convenient to assemble and disassemble.

4) The clearance between the outer diameter of the expansion sleeve and the inner hole of the part of the processed bushing and the inner hole of the part of the shaft sleeve is less than 0.005mm, and the part with high coaxiality can be processed. Different outer diameters of the expansion sleeve can be selected according to the coaxiality precision requirement of the processed part.

5) After the clamp body 1, the expansion sleeve 2 and the processed part are installed, a gasket 3 and a screw 4 are used for positioning and clamping. The parallelism of the two end surfaces of the gasket 3 is generally not more than 0.03mm, and the parallelism requirement of the two end surfaces of the gasket 3 can be determined according to the precision of the actual processed part. The screw 4 adopts quenching heat treatment, metal materials with high mechanical property are selected, and the screw clamping force cannot be overlarge. The gasket is generally made of copper alloy; the screw is made of stainless steel.

6) The width of the notch 21 is 2mm, and the notch can be easily taken down from the expansion sleeve after the workpiece is machined. The outer diameter of the limiting round table 11 is 56mm, the outer diameter of the cylindrical structure is 46mm, and the length of the cylindrical structure is 34mm; the length of the conical structure is 49mm, and the length of the clamp body 1 is 94mm; the outer diameter of the expansion sleeve 2 is 46mm, and the length is 41mm; the length of the screw thread part of the screw hole of the fixture body 1 is 25mm.

The specific fixture use process and the bushing machining result are as follows:

1) The soft core shaft body is arranged on a lathe chuck (through a cylindrical structure), the conical surface of the clamp body is aligned by striking a watch, the watch jumps to a value not more than 0.02 mm, and the clamp body is clamped. And then correcting the conical surface of the clamp body to be 14 degrees, actually processing the 14-degree conical surface according to the actual conical surface of the expansion sleeve, wherein the bonding degree of the conical surface of the clamp body and the expansion sleeve after processing is 95 percent, and after correcting the matching surface of the clamp body, the error between the center of the clamp body and the center of the spindle of the lathe is 0.

2) And selecting an expansion sleeve according to the actual size of the inner hole of the machined bushing, wherein the clearance between the outer diameter of the expansion sleeve and the inner diameter of the bushing is not more than 0.005 mm. Then the expansion sleeve and the bush are arranged on the fixture body, and are positioned and clamped by a gasket and a screw. The clamping force is small, in fact, in the screw tightening process, a dial indicator is used for detecting the outer circle of the bushing in real time, the dial indicator jump value is about 0.001-0.003 mm, namely, the screw tightening is stopped.

3) And machining the lining on a numerical control lathe after the clamping.

4) And (3) machining, wherein the roundness of the outer circle of the bushing is 0.003mm, the cylindricity of the outer circle is 0.004 mm, and the coaxiality of the outer circle to the inner hole is phi 0.004 mm through three-coordinate measurement.

The utility model discloses a soft dabber anchor clamps realizes that soft dabber anchor clamps center is 0 with lathe main shaft axiality error after the clamping, and soft dabber can eliminate the axiality error of dabber and lathe main shaft promptly after installing car (grinding) bed.

Claims (6)

1. A soft mandrel clamp is characterized by comprising a clamp body (1), an expansion sleeve (2), a gasket (3) and a screw (4); the clamp body (1) is of a shaft-shaped structure, a limiting circular truncated cone (11) is arranged in the middle of the shaft-shaped structure, the clamp body (1) located on one side of the limiting circular truncated cone (11) is of a cylindrical structure, and the outer diameter of the clamp body (1) located on the other side of the limiting circular truncated cone (11) is of a conical structure which is shrunk outwards from the limiting circular truncated cone (11); the center of the end surface of the conical structure is provided with a screw hole matched with the screw (4) along the axial direction; the section of the inner cavity of the expansion sleeve (2) is in a cone shape matched with the cone-shaped structure; a notch (21) which penetrates through the front and the back of the expansion sleeve (2) is formed on the side wall of the expansion sleeve (2); the outer diameter of the gasket (3) is larger than the inner diameter of the small-caliber side of the expansion sleeve (2) and smaller than the outer diameter of the expansion sleeve (2), and a screw hole is also formed in the center of the gasket (3); the conicity of the conical structure and the conicity of the inner cavity of the expansion sleeve (2) are both 14 degrees.

2. The soft mandrel clamp as claimed in claim 1, wherein the clamp body (1) is made of 40Cr, and the hardness is HRC 32-HRC 38.

3. A soft mandrel clamp according to claim 1 or claim 2 characterised in that the sleeve (2) is made of brass H62.

4. A soft mandrel holder as claimed in claim 1 or 2 wherein said slits (21) are 2mm wide.

5. The soft mandrel holder of claim 4, wherein the limiting boss (11) has an outer diameter of 56mm, a cylindrical structure outer diameter of 46mm and a length of 34mm; the length of the conical structure is 49mm, and the length of the clamp body (1) is 94mm; the outer diameter of the expansion sleeve (2) is 46mm, and the length is 41mm; the length of the screw thread part of the screw hole of the fixture body (1) is 25mm.

6. A soft mandrel holder as claimed in claim 4, characterised in that the parallelism of the two end faces of the shim (3) is not more than 0.03mm.

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