Rotary spindle workpiece anti-deflection easy-to-adjust clamping device with optimized stability

Abstract

A rotation main shaft workpiece anti-deflection easy-to-adjust clamping device with optimized stability is characterized in that a rolling bearing (319) is sleeved on the front section of the outer wall of a shell (314), a synchronous pulley (311) is sleeved outside the rolling bearing (319), a driving plate (308) is pressed at the front ends of the rolling bearing (319) and the synchronous pulley (311), the front end of the shell (314) is connected with a clamp body (304), and a spring clamping jaw (303) is lined on the inner wall of an axial middle hole of the shell (314) and the inner wall of an axial middle hole of the clamp body (304). The front end faces of the clamp body (304) and the spring clamping jaw (303) are connected with the end cover (302) in a pressing mode. And the adjusting nut (305) is coaxially embedded in the inner wall of the rear section of the middle hole of the clamp body (304) in a diameter-expanding manner. The multi-stage composite clamping adjusting mechanisms which are coordinated and matched with one another are arranged in a combined mode, and the coaxiality error of the outer conical surfaces of the clamping jaws and the inner holes is not larger than 0.002 mm; and the radial run-out of the end part of the main shaft is controlled to be 0.003 mm. And clamping is stable, and the continuity and stability of the initial clamping force of the clamping device in the machining process are guaranteed. And disassembly, assembly and maintenance are convenient. Adjusting and loosening are accurate and convenient, sliding is smooth and safe, driving is convenient, the machining effect and machining quality are guaranteed, and the application range is wide.

Description

Technical Field

[0001] The present invention belongs to the technical field of clamping, supporting and positioning devices for workpieces or tools in metal machining or finishing generally fixed on the spindle of a machine tool of IPC classification B23Q3 / 12, and in particular relates to a structural improvement technology for a special workpiece clamping device of a rotary spindle with optimized stability. Background Art

[0002] The special workpiece clamping device for the rotary spindle is an important component of the machine tool. It is mainly used to fix the workpiece to ensure that the workpiece can be processed stably and accurately under the drive of the rotary spindle.

[0003] The workpiece clamping device usually consists of a chuck, a drive device, a positioning device and a gasket. The chuck is the part that holds the workpiece. It consists of a fixed jaw and a movable jaw. The movement and clamping force of the jaws are controlled by a screw adjuster. The drive device is responsible for providing power so that the chuck can clamp or release the workpiece. Common power sources include hydraulic, pneumatic and electromagnetic. The positioning device ensures that the chuck can accurately position the workpiece to ensure processing accuracy. The gasket is used to cooperate with the chuck and the workpiece surface to disperse the pressure and prevent damage to the workpiece surface.

[0004] When the drive receives the signal, the dedicated workpiece clamping device of the rotary spindle starts working and clamps the workpiece through the claws of the chuck. For hydraulic and pneumatic clamping devices, the power source transmits pressure to the chuck through the pipeline, so that the movable part of the claw moves and clamps the workpiece. For electromagnetic clamping devices, the workpiece is attracted by electromagnetic force. The positioning of the chuck is guaranteed by initial positioning, clamping force and hydraulic or pneumatic pressure stability control.

[0005] The Chinese invention patent application CN201711097253.5 is entitled: A universal fixture for machining an engine crankshaft crank pin, comprising a first fixture and a second fixture clamped on a machine tool, wherein the first fixture is used to clamp one end of the crankshaft crank pin to be machined, and the second fixture is used to clamp the other end of the crankshaft crank pin to be machined, the openings of the clamping positions of the first fixture and the second fixture are adjustable respectively, and the rotation center positions of the first fixture and the second fixture are adjustable in two directions perpendicular to each other. The device realizes the clamping of different crankshafts by the left and right movement of the combined V-block and the up and down movement of the left / right pressure block, and quickly realizes the coincidence of the rotation center line of the crankshaft crank pin shaft section to be machined with the rotation center axis line of the machine tool.

[0006] Patent application 202210752774.4 provides a dual-purpose oil and gas four-jaw two-position centering rotary clamp, comprising: a seat body, a rotating spindle is provided inside the seat body, a stacked telescopic sleeve assembly is provided on the rotating spindle, the telescopic sleeve assembly comprises an outer telescopic sleeve and at least one inner telescopic sleeve slidingly sleeved inside the outer telescopic sleeve, both the outer telescopic sleeve and the inner telescopic sleeve can slide along the axis direction of the rotating spindle, the rotating spindle is provided with a fluid power channel for driving the telescopic sleeve assembly to slide, a clamping device for clamping a workpiece is provided at the side end of the telescopic sleeve assembly, and the clamping device comprises a first clamping mechanism and a second clamping mechanism.

[0007] Patent application 202320795092.1 discloses an engine crankshaft finishing clamping device for connecting the crankshaft to a machine tool spindle, comprising: a fixed plate, a clamping assembly and a measuring assembly, the fixed plate being used to connect the machine tool spindle, the clamping assembly comprising a sliding member, a clamping member and a locking member, the sliding member being slidably connected to the fixed plate along the radial direction of the machine tool spindle, and being arranged on the side of the fixed plate facing away from the machine tool spindle, the clamping member being connected to the sliding member for clamping the crankshaft, the locking member being connected to the clamping member and being tightly pressed against the fixed plate for limiting the sliding of the clamping member relative to the fixed plate, the measuring assembly comprising a first measuring body and a second measuring body, the first measuring body being connected to the fixed plate, the second measuring body being arranged relative to the first measuring body and being connected to the clamping member, and a measuring gap being formed between the second measuring body and the first measuring body for measuring the deviation distance.

[0008] The rotary fixture is a mechanical device used to clamp the workpiece on the machine tool. It is a machine tool accessory that uses the radial movement of the movable jaws evenly distributed on the chuck body to clamp the workpiece in place. It is a precision fixture.

[0009] Existing rotary spindle rotary fixtures, especially for workpieces with high precision requirements, especially for workpieces with long axial dimensions, may experience deflection during processing due to insufficient stability at high speeds, resulting in poor user experience and affecting processing quality and efficiency. Summary of the invention

[0010] The present invention provides a rotary spindle workpiece anti-sway easily adjustable clamping device with optimized stability, aiming to improve the problem of the existing rotary spindle rotating fixture having insufficient stability and causing the sway when working at high speed.

[0011] To this end, the present invention includes: an end cover, a spring clamp, a clamp body, an adjustment nut, a dial, a synchronous pulley, a housing and a rolling bearing. The rolling bearing is sleeved on the front section of the outer wall of the housing, the synchronous pulley is sleeved on the outer side of the rolling bearing, the rolling bearing and the front end of the synchronous pulley are crimped with the dial, the front end of the housing is connected to the clamp body, the spring clamp is lined on the inner wall of the axial middle hole of the housing and the clamp body, and the clamp body and the front end of the spring clamp are crimped with the end cover; the inner wall of the rear section of the middle hole of the clamp body is expanded and coaxially embedded with the adjustment nut. A multi-stage composite clamping and adjusting mechanism that coordinates with each other is set, and the coaxiality error between the outer cone surface of the clamp and the inner hole is not greater than 0.002mm; the radial runout of the end of the spindle is controlled within 0.003mm.

[0012] The inner wall groove of the housing is cast with a 1.5mm thick tin bronze layer, and a number of axial oil grooves are evenly distributed. The clamp body is installed on the front end of the spindle, and the inner conical surface of the clamp body is coaxial with the axis of rotation of the spindle. The left end face of the dial presses the outer ring of the rolling bearing, and the gland is tightened to press the inner ring of the rolling bearing and then connected to the outer edge of the rear end of the housing through a thread.

[0013] Furthermore, to achieve the above object, the present invention is configured as follows:

[0014] A support ring is coaxially embedded and crimped into the rear side of the adjusting nut in the expanded diameter middle hole of the rear section of the clamp body.

[0015] A ring groove is arranged around the axial hole at the rear end face of the dial, in which a ring-shaped pressure cover is embedded and installed, and the rolling bearing is pressed by the pressure cover.

[0016] The rolling bearing is lined with an adjusting gasket.

[0017] A bushing is installed on the inner wall of the rear end of the hole in the spring clamp.

[0018] An annular lining plate is coaxially mounted on the rear side of the spring clamp.

[0019] The outer wall of the clamp body is radially provided with a through-hole-shaped notch with an inclined inner wall.

[0020] An annular groove is arranged on the outer edge of the front section of the housing, and a synchronous pulley is mounted on the outer side of the rolling bearing through a sleeve, and a fourth screw is installed on the edge of the ring platform at the rear end of the annular groove.

[0021] The inner wall of the dial hole is sleeved with an annular first skeleton rotary sealing ring, and a ring platform is arranged around the hole of the rear end face of the synchronous pulley, in which a second skeleton rotary sealing ring is embedded.

[0022] Compared with the prior art, the beneficial effects of the present invention are: a multi-stage composite clamping adjustment mechanism is set up in coordination with each other, the housing, spring clamp and clamp body are installed on the main shaft of the machine tool, the clamping is stable, and the continuity and stability of the initial clamping force of the clamping device during the processing are guaranteed. The processing efficiency and processing quality can be improved, and disassembly and maintenance are convenient. The adjustment and release are accurate and convenient, the sliding is smooth and safe, the driving is convenient, the processing effect and processing quality are ensured, and the application range is wide; the workpiece can be grasped, adjusted and unloaded with high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings are for illustration only and should not be construed as limiting the present invention in any way. By referring to the following drawings, readers can understand the embodiments of the present invention and further understand the advantages and technical features of the present invention.

[0024] Figure 1 This is a structural diagram of Example 1 of the present invention.

[0025] Reference numerals include:

[0026] 300-workpiece, 301-spindle, 302-end cover, 303-spring clamp, 304-clamp body, 305-adjusting nut, 306-wrench, 307-support ring, 308-dial, 309-pressure cover, 310-adjusting gasket, 311-synchronous pulley, 312-bushing, 313-lining plate, 314-housing, 315-notch, 316-sealing gasket, 317-first skeleton rotating sealing ring, 318-second skeleton rotating sealing ring, 319-rolling bearing, 320-first screw, 321-second screw, 322-third screw, 323-fourth screw, 324-fifth screw. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. In the event of a conflict, the definitions in this specification shall prevail.

[0029] It should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. The terms "include" and "have" and any of their variations are intended to cover other possible choices under the same logic that are not listed. In the description of the present invention, the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship usually placed when the invention product is used. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", "overhanging", etc. do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. In the event of a conflict, the definitions in this specification shall prevail.

[0031] The present invention comprises: a main shaft 301 , an end cover 302 , a spring clamp 303 , a clamp body 304 , an adjustment nut 305 , a dial 308 , a synchronous pulley 311 , a housing 314 and a rolling bearing 319 .

[0032] The content of the present invention can be more easily understood by referring to the following preferred implementation methods of the present invention and the included examples.

[0033] Embodiment 1: As attached Figure 1 As shown, a spanner 306 is inserted into the radial hole on the outer wall of the adjusting nut 305. The rear end of the workpiece 300 is inserted into the hole in the end cover 302 and then clamped between a group of spring clamps 303 distributed in an annular manner.

[0034] In the embodiment of the present invention, the clamp body 304 is fixed to the spindle 301 by the third screws 322 distributed circumferentially, and the periphery of the annular end cover 302 is fixed to the front end surface of the clamp body 304 by a group of second screws 321. The clamp body 304 is equipped with a spring clamp 303 for clamping the workpiece 300. The rear part of the spring clamp 303 extends into the inner hole of the spindle 300 for positioning to ensure the coaxiality of the center of the workpiece 300 and the center of the spindle 301. It should be noted that when the clamp body 304 is installed on the front end of the spindle 301, it should be ensured that its inner conical surface is coaxial with the rotation axis of the spindle 301, and the coaxiality error between the outer conical surface of the clamp 303 and the inner hole should not be greater than 0.002mm.

[0035] In the embodiment of the present invention, further, a lining plate 313 installed in the inner hole of the main shaft 301 is used to support the distal end of the workpiece 300 extending into the main shaft 301 .

[0036] In the embodiment of the present invention, further, an annular groove is provided at the outer edge of the front section of the housing 314, and the rolling bearing 319 is mounted on the outer sleeve of the synchronous pulley 311 through the sleeve bushing, and the fourth screw 323 is installed on the edge of the ring platform at the rear end of the annular groove, and the axial installation position of the synchronous pulley 311 is accurately adjusted by screwing the fourth screw 323. A bushing 312 is provided at the rear section of the inner wall of the spring clamp 303, and correspondingly, a ring platform is provided on the inner wall of the deep part of the central axis hole inside the main shaft 301, and a ring-shaped liner 313 is crimped by the fifth screw 324. The rear end head of the workpiece 300 is inserted and fixed in the middle hole of the liner 313, and the outer wall of the rear end of the workpiece 300 is clamped into the inner wall of the bushing 312, so as to ensure that the rear end of the workpiece 300 is stable and centered.

[0037] In the embodiment of the present invention, the adjusting nut 305 is pressed onto the front end surface of the main shaft 301 through the supporting ring 307. Furthermore, a sealing gasket 316 is provided on the pressing interface between the main shaft 301 and the clamp body 304.

[0038] In the embodiment of the present invention, as a precision bearing assembly, an adjustment gasket 310 is installed on the inner side of the rolling bearing 319. The specific assembly method includes: stacking two rolling bearing monomers horizontally, shimming the outer ring of the lower rolling bearing monomer; separating the inner rings of the two rolling bearing monomers with a spacer; applying a preset force, i.e., the preload force after installation, to the outer ring of the upper rolling bearing monomer; then, measuring the height value between the outer rings of the two rolling bearing monomers, and the height difference between the height value and the spacer separating the two rolling bearing monomers is the thickness difference between the two gaskets of the inner and outer rings of the rolling bearing monomers. The left end face of the trimming dial 308 is pressed to tighten the outer ring of the rolling bearing 319, and the pressure cover 309 is tightened to press the inner ring of the rolling bearing 319, and then connected to the outer edge of the rear end of the housing 314 through a thread.

[0039] In the embodiment of the present invention, further, an adjusting nut 305 is installed in the clamp body 304, which is matched with the outer thread of the spring clamp jaw 303. A notch 315 with a certain angle is opened on the circumferential surface of the clamp body 304 corresponding to the axial position of the adjusting nut 305. There are several radial holes on the outer circumference of the adjusting nut 305, which are aligned with the notch 315 set on the outer wall of the clamp body 304. The wrench 306 is inserted into the radial hole on the circumferential surface of the adjusting nut 305 through the notch 315, and can be turned around the axis of the clamp body 304 to adjust the nut 305, so as to further adjust the coaxial mounting support ring 307 on the rear side of the nut 305. The size of the support ring 307 can be adjusted to just eliminate the axial clearance of the adjusting nut 305 in the clamp body 304, but the adjusting nut 305 can be rotated in the clamp body 304.

[0040] In the embodiment of the present invention, further, the wrench 306 is turned to drive the adjusting nut 305 to rotate. Since the adjusting nut 305 is limited in the axial movement space, the elastic clamping jaw 303 can only move axially; the conical inner wall at the front end of the spring clamping jaw 303 will shrink in radial dimension in proportion while moving axially, thereby achieving the purpose of clamping the workpiece 300. The front end cover 302 can provide an axial positioning reference surface for installing the workpiece 300.

[0041] In the embodiment of the present invention, further, the main shaft 301 is connected to the dial 308 through the third screw 322, the dial 308 is connected to the synchronous pulley 311 through the first screw 320, the synchronous pulley 311 is supported on the front end outer edge of the shell 314 through the rolling bearing 319, the pressure cover 309 fixes the rolling bearing shaft 319 on the shell 314, and at the same time, there is a gap between the dial 308 and the pressure cover 309 and they can rotate relative to each other; the gap of the rolling bearing 319 can be eliminated by adjusting the thickness of the gasket 310, so that the synchronous pulley 311 can rotate smoothly without swaying; the first skeleton rotating seal ring 317 is embedded in the inner edge of the dial 308, and the second skeleton rotating seal ring 318 is embedded in the inner edge of the rear port of the synchronous pulley 311 to protect the rolling bearing 319. The skeleton rotary seal ring 317 prevents leakage of the oil pool of the main shaft 301 and also prevents the coolant used for external processing from flowing into the oil pool of the main shaft 301 and the rolling bearing 319; the skeleton rotary seal ring 318 mainly prevents the coolant used for external processing from flowing into the rolling bearing 319.

[0042] In the embodiment of the present invention, further, the synchronous pulley 311 is driven to rotate by the motor through the synchronous belt transmission, thereby driving the main shaft 301 and the workpiece 300 to rotate.

[0043] In the embodiment of the present invention, manual operation is first performed to insert and move the handle 306 to drive the adjusting nut 305 to rotate and then drive the clamping jaw 303 to move left to achieve radial contraction and clamp the workpiece 300. After the workpiece 300 is clamped, it is necessary to remove the wrench 306 and then rotate the spindle 301 to perform processing.

[0044] Preferably, a 1.5 mm thick tin bronze layer is cast on the inner wall of the shell 314, and the tin bronze layer is in the gap between the shell 314 and the spindle 301. The tin bronze layer surrounds the hardened outer wall of the spindle 301 inwardly to improve the friction performance between the inner wall of the shell 314 and the outer wall of the spindle 301. In addition, the inner wall of the shell 314 is precisely scraped to ensure the uniformity of the contact between the inner wall of the shell 314 and the outer wall of the spindle 301. Further, a plurality of axial oil grooves are evenly distributed on the surface circumference of the cast tin bronze layer on the inner wall of the shell 314 to improve the lubrication performance between the inner wall of the shell 314 and the outer wall of the spindle 301; and the spindle 301 is immersed in the oil pool. These measures ensure the precision and accuracy of the rotation of the spindle 301, and the radial runout of the end of the spindle 301 is controlled at 0.003 mm. Among them, tin bronze contains 3% to 14% tin, and phosphorus, zinc, lead and other elements are often added. It is corrosion-resistant and wear-resistant, has good mechanical properties and process properties, and can be well welded and brazed. It does not produce sparks when impacted. It is divided into processed tin bronze and cast tin bronze. The tin content of cast tin bronze is 10% to 14%. Tin bronze is a non-ferrous metal alloy with the smallest casting shrinkage rate. It can be used to produce castings with complex shapes, clear contours and low airtightness requirements. Tin bronze is very corrosion-resistant in the atmosphere, seawater, fresh water and steam. Phosphorus-containing tin bronze has good mechanical properties and can be used as wear-resistant parts and elastic parts of high-precision machine tools. Lead-containing tin bronze is often used as wear-resistant parts and sliding bearings.

[0045] Based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

Claims

1. A rotating spindle workpiece anti-sway and easily adjustable clamping device with optimized stability, comprising an end cover (302), a spring clamp (303), a clamp body (304), an adjustment nut (305), a dial (308), a synchronous pulley (311), a housing (314) and a rolling bearing (319); characterized in that: The front section of the outer wall of the shell (314) is sleeved with a rolling bearing (319), the rolling bearing (319) is sleeved with a synchronous pulley (311), the front ends of the rolling bearing (319) and the synchronous pulley (311) are crimped with a dial (308), the front end of the shell (314) is connected to the clamp body (304), the inner wall of the axial middle hole of the shell (314) and the clamp body (304) is lined with a spring clamping claw (303), and the front end surface of the clamp body (304) and the spring clamping claw (303) is crimped with an end cover (302); the inner wall of the rear section of the middle hole of the clamp body (304) is enlarged and coaxially embedded with an adjusting nut (305); a multi-stage composite clamping adjustment mechanism that cooperates with each other is set, and the coaxiality error between the outer cone surface of the clamping claw 303 and the inner hole is not greater than 0.002mm; the radial runout of the end of the main shaft 301 is controlled within 0.003mm.

2. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1 is characterized in that: A bushing (312) is installed on the inner wall of the rear end of the hole in the spring clamp (303).

3. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: An annular lining plate (313) is coaxially mounted on the rear side of the spring clamp (303).

4. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: A support ring (307) is coaxially embedded and crimped into the rear side of the adjusting nut (305) in the expanded middle hole of the rear section of the clamp body (304).

5. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: The clamp body (304) is installed on the front end of the main shaft (301), and the inner conical surface of the clamp body (304) is coaxial with the rotation axis of the main shaft (301).

6. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: The rear end face of the dial (308) has an annular groove around the axial hole, in which an annular pressure cover (309) is embedded and installed, and the rolling bearing (319) is pressed by the pressure cover (309).

7. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: The inner wall of the middle hole of the dial (308) is sleeved with an annular first skeleton rotary sealing ring (317), and a ring platform is arranged around the middle hole of the rear end surface of the synchronous pulley (311), in which a second skeleton rotary sealing ring (318) is embedded.

8. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: The inner wall groove of the shell (314) is cast with a 1.5 mm thick tin bronze layer, and a plurality of axial oil grooves are evenly opened.

9. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 1, characterized in that: The rolling bearing (319) is lined with an adjusting gasket (310).

10. The anti-sway and easily adjustable clamping device for a rotary spindle workpiece with optimized stability according to claim 6, characterized in that: The left end surface of the dial (308) presses the outer ring of the rolling bearing (319), and the pressure cover (309) presses the inner ring of the rolling bearing (319) and is connected to the outer edge of the rear end of the housing (314) through a thread.

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