Special clamp for milling key groove in shifting fork handle shaft in vertical machining center

Abstract

The invention relates to the technical field of machining, in particular to a special fixture for a vertical machining center to mill a key groove in a shifting fork handle shaft, which comprises a bottom plate, and a plurality of groups of fixture units are mounted on the bottom plate. Each group of clamp unit comprises two V-shaped blocks which are symmetrically arranged, pressing plate assemblies which are in one-to-one correspondence with the V-shaped blocks, and a positioning assembly which is positioned on the V-shaped block on one side; the bottom face of the V-shaped block is fixed to the bottom plate, and a V-shaped groove used for containing a shifting fork handle shaft is formed in the top face of the V-shaped block. The positioning assembly is used for positioning a shifting fork; the pressing plate assembly is used for pressing and fixing the shifting fork handle shaft to the V-shaped block. The clamp has the advantages that a plurality of workpieces can be mounted on one clamp plate at a time, the positioning assemblies, the pressing plate assemblies and the limiting assemblies on the clamp can ensure accurate positioning of the workpieces, the structure is simple, operation is convenient, the machining efficiency can be improved, meanwhile, the workpieces can be assembled offline, unmanned assembly line operation on a machine tool line can be achieved, and the purpose of a flexible production line is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to a special clamp used for milling a keyway on a fork handle shaft in a vertical machining center. Background Art

[0002] In mechanical processing, keyway processing is a relatively common mechanical processing method. It is usually processed using a keyway milling cutter after positioning and clamping with a V-block. During the processing, the dimensional accuracy and symmetry requirements of the keyway must be guaranteed.

[0003] At present, in order to improve the processing efficiency and processing accuracy, people usually consider streamlining the internal structure of parts and improving the processing requirements of parts, and rarely make improvements on the processing fixtures.

[0004] Based on this, this case is brought forward. Summary of the invention

[0005] The purpose of the present invention is to provide a special fixture for milling a keyway on a fork handle shaft of a vertical machining center, so as to improve machining efficiency and machining accuracy.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A special fixture for milling a keyway on a fork handle shaft of a vertical machining center, comprising a base plate, on which a plurality of sets of fixture units are mounted, each set of fixture units comprising two symmetrically arranged V-shaped blocks, a pressure plate assembly corresponding to the V-shaped blocks one by one, and a positioning assembly located on one side of the V-shaped block;

[0008] The bottom surface of the V-shaped block is fixed to the bottom plate, and the top surface is provided with a V-shaped groove for placing the fork handle shaft;

[0009] The positioning assembly is used to position the shift fork;

[0010] The pressing plate assembly is used to press down the shift fork handle shaft and fix it on the V-block.

[0011] Furthermore, the base plate is provided with a keyway and a screw hole, the V-block is provided with a mounting hole corresponding to the screw hole and a key with a clearance fit with the keyway, and the V-block is fixedly connected to the base plate by the key and bolts.

[0012] Furthermore, the keyway 1 is an oblong hole type and is arranged along the axial direction of the fork, each keyway 1 is equipped with several groups of screw holes 1, several groups of screw holes 1 are arranged along the length direction of the keyway 1, and the two screw holes of each group of screw holes 1 are respectively arranged on both sides of the width direction of the keyway 1.

[0013] Furthermore, the positioning assembly includes a handle assembly, a positioning rod, a pin and a spring;

[0014] The positioning rod comprises an inserting section and a connecting section, and the diameter of the inserting section is larger than the diameter of the connecting section;

[0015] The handle assembly includes a hand wheel and a limiting part, the limiting part includes an axial limiting block and an anti-rotation limiting short column, one side of the axial limiting block is fixed to the anti-rotation limiting short column, and the other side is fixed to the hand wheel, a pin hole 1 is provided on the axial limiting block, a pin hole 2 corresponding to the pin hole 1 is provided on the insertion section, a mounting hole 2 for inserting the connecting section is provided on the axial limiting block, the mounting hole 2 is connected to the pin hole 1, and the pin shaft can be inserted into the pin hole 1 and the pin hole 2;

[0016] The V-shaped block is provided with a mounting hole 3 matching the insertion section, a mounting hole 4 matching the connection section, and a mounting hole 5 matching the anti-rotation limiting short column. The mounting hole 3 and the mounting hole 4 are coaxial and interpenetrating. The cross-sectional dimension of the mounting hole 3 is smaller than the cross-sectional dimension of the axial limiting block.

[0017] A limiting step is formed at the junction of the mounting hole three and the mounting hole four, and the spring is arranged in the mounting hole four, with two ends respectively resting on the limiting step and the end surface of the insertion section.

[0018] Furthermore, the pressure plate assembly includes a special screw, two special nuts and a special pressure plate. The base plate is provided with a special screw hole corresponding to the special screw. After the special screw is screwed into the special screw hole, one of the special nuts is screwed to the bottom of the special screw and tightens the base plate. The special pressure plate is slidably connected to the special screw and is located above the V-block. It is used to press down the fork handle shaft placed in the V-groove. The other special nut is located above the special pressure plate. After the special screw is screwed in, downward pressure is applied to the special pressure plate.

[0019] Furthermore, it includes a limit rod, which is fixed on the base plate and is located on one or both sides of the axial direction of the clamp unit and is used to abut against the end surface of the fork handle shaft.

[0020] Furthermore, the limit rod includes a connecting section and a limiting section. The base plate is provided with a mounting hole six. The connecting section of the limit rod is inserted into the mounting hole six with an interference fit, and the limiting section is used to abut against the end face of the fork handle shaft.

[0021] Furthermore, the limiting rod includes an external threaded section located between the connecting section and the limiting section.

[0022] Furthermore, at least two groups of clamp units are included, and the two groups of clamp units share a limiting rod, the two groups of clamp units are arranged side by side, and the limiting rod is located between the two groups of clamp units.

[0023] The advantages of the present invention are that multiple workpieces can be installed on a fixture plate at one time, the positioning assembly, pressure plate assembly and limit assembly on the fixture can ensure accurate positioning of the workpieces, the structure is simple and the operation is convenient, which can improve the processing efficiency. At the same time, the workpieces can be assembled offline and the machine tool line can be operated without an assembly line, thus realizing the purpose of a flexible production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the three-dimensional structure of a workpiece to be processed - a shift fork in an embodiment;

[0025] Figure 2 A schematic diagram of the three-dimensional structure of the special fixture in the embodiment;

[0026] Figure 3 It is a top view schematic diagram of assembling a workpiece to be processed on a special fixture in the embodiment;

[0027] Figure 4 for Figure 3 A schematic diagram of the main view;

[0028] Figure 5 A schematic diagram of a three-dimensional structure in which a single fixture unit is assembled on a bottom plate in an embodiment;

[0029] Figure 6 for Figure 5 A top view schematic diagram of

[0030] Figure 7 for Figure 6 AA cross-sectional view of ;

[0031] Figure 8 for Figure 6 BB cross-sectional view;

[0032] Fig. 9 An exploded schematic diagram of a positioning assembly and a pressing plate assembly in an embodiment;

[0033] Fig.10 A schematic diagram of the three-dimensional structure of a V-shaped block in the embodiment;

[0034] Fig.11 A schematic cross-sectional view of a V-shaped block in an embodiment;

[0035] Fig.12 A schematic cross-sectional view of a positioning assembly and a V-shaped block in an embodiment;

[0036] Description of symbols

[0037] 1. Fork; 101. Keyway to be cut and milled; 102. Shaft hole; 103. Handle shaft;

[0038] 2. Bottom plate; 201. Keyway 1; 202. Screw hole 1; 203. Mounting hole 6; 204. Special screw hole;

[0039] 3. V-shaped block; 301. V-shaped groove; 302. Mounting hole 1; 303. Key 1; 304. Mounting hole 3; 305. Mounting hole 4; 306. Mounting hole 5; 307. Limiting step;

[0040] 4. Positioning assembly; 401. Hand wheel; 402. Axial limit block; 403. Anti-rotation limit short column; 404. Pin hole 1; 405. Mounting hole 2; 406. Positioning rod; 4061. Connecting section; 4062. Insertion section; 4063. Pin hole 2; 407. Spring; 408. Pin shaft;

[0041] 5. Pressing plate assembly; 501. Special screw; 502. Special nut; 503. Special pressing plate;

[0042] 6. Limit rod; 601. Connecting section; 602. External thread section; 603. Limit section. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with the embodiments. It should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" herein are based on the directions or positional relationships shown in the accompanying drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0044] like Figure 1 As shown, the workpiece to be processed that needs to be clamped by the special fixture of this embodiment is a shift fork 1, which has shaft holes 102 at the bottom of both sides and is also equipped with a handle shaft 103. After the workpiece is clamped on the special fixture, a keyway 101 needs to be milled on the handle shaft 103, and the clamping stability of the workpiece to be processed needs to be ensured during the milling process.

[0045] like Figures 2 to 12 As shown, this embodiment proposes a special fixture for milling the keyway on the handle shaft 103 of the fork 1 in a vertical machining center, including a base plate 2, on which 8 sets of fixture units are arranged in two columns and four rows. Each set of fixture units includes two symmetrically arranged V-blocks 3, a pressure plate assembly 5 corresponding to the V-blocks 3 (i.e., two pressure plate assemblies 5), and a positioning assembly 4 located on one side of the V-block 3.

[0046] refer to Figure 5 , Figure 7 , Figure 8 and Fig.10The bottom surface of the V-shaped block 3 is fixed to the bottom plate 2 in the following manner: the bottom plate 2 is provided with a keyway 201 and a screw hole 202, the V-shaped block 3 is provided with a mounting hole 302 corresponding to the screw hole 202, and a key 303 having a clearance fit with the keyway 201, and the V-shaped block 3 is fixedly connected to the bottom plate 2 by means of a key and a bolt. Figure 5 As shown, under each set of clamp units, the keyway 201 under one of the V-blocks 3 is an oblong groove, but the length of the oblong groove is slightly larger than the key 303. After the V-block 3 is inserted into the keyway 201, it cannot move left and right. Therefore, only one group of screw holes 202 is provided there, and the two screw holes of one group of screw holes 202 are respectively provided on both sides of the width direction of the oblong groove; under each set of clamp units, the keyway 201 under another V-block 3 is an oblong groove, but the length of the oblong groove is more than twice the length of the key 303. After the V-block 3 is inserted into the keyway 201, it can be adjusted to move left and right according to the axial size of the workpiece to be processed. Therefore, multiple groups of screw holes 202 are provided there (two groups in this embodiment), and the two screw holes of each group of screw holes 202 are respectively provided on both sides of the width direction of the oblong groove.

[0047] like Figure 3 and Fig.10 As shown, the top surface of the V-shaped block 3 is provided with a V-shaped groove 301 for placing the handle shaft 103 of the fork 1. When the upper pressure plate assembly 5 applies downward pressure, the handle shaft 103 of the fork 1 can be pressed down and fixed on the V-shaped block 3 to prevent it from shaking forward and backward.

[0048] refer to Figure 5 and Fig. 9 The pressure plate assembly 5 includes a special screw 501, two special nuts 502 and a special pressure plate 503. The base plate 2 is provided with a special screw hole 204 corresponding to the special screw 501. After the special screw 501 is screwed into the special screw hole 204, one of the special nuts 502 is screwed to the bottom of the special screw 501 and pressed against the base plate 2, so that the special screw 501 can be fixed. The special pressure plate 503 is sleeved on the special screw 501 and can slide up and down relative to the special screw 501. The special pressure plate 503 is located above the V-block 3 and is used to press down the handle shaft 103 of the fork 1 placed in the V-groove 301. The other special nut 502 is located above the special pressure plate 503. After being screwed into the special screw 501, downward pressure is applied to the special pressure plate 503.

[0049] The positioning assembly 4 includes a handle assembly, a positioning rod 406, a pin 408 and a spring 407. Figure 8 , Fig. 9 , Fig.11 , Fig.12As shown, the positioning rod 406 includes an insertion section 4062 and a connecting section 4061, and the diameter of the insertion section 4062 is larger than the diameter of the connecting section 4061. The handle assembly includes a hand wheel 401 and a limiting portion, the limiting portion includes an axial limiting block 402 and two anti-rotation limiting short columns 403, one side of the axial limiting block 402 is fixed to the two anti-rotation limiting short columns 403, and the other side is fixed to the hand wheel 401, the axial limiting block 402 is provided with a pin hole 1 404, the insertion section 4062 is provided with a pin hole 2 4063 corresponding to the pin hole 1 404, the center of the axial limiting block 402 is provided with a mounting hole 2 405 for the connecting section 4061 to be inserted, the mounting hole 2 405 is communicated with the pin hole 1 404, and the two anti-rotation limiting short columns 403 are located on both sides of the mounting hole 2 405. The V-shaped block 3 is provided with a mounting hole 304 matching the insertion section 4062, a mounting hole 405 matching the connection section 4061, and two mounting holes 506 matching the anti-rotation limiting short column 403. Due to the matching arrangement, the diameter of the mounting hole 405 is larger than that of the mounting hole 304. The mounting hole 304 and the mounting hole 405 are coaxial and interpenetrating. The two mounting holes 506 are located at the upper and lower sides of the mounting hole 304. The cross-sectional dimension of the mounting hole 304 is smaller than that of the axial limiting block 402. A limiting step 307 is formed at the junction of the mounting hole 305 and the mounting hole 405. The spring 407 is arranged in the mounting hole 405, and both ends are respectively against the limiting step 307 and the end surface of the insertion section 4062. When the spring 407 is compressed, the insertion section 4062 is located in the mounting hole 405. When the spring 407 is stretched, the insertion section 4062 is exposed from the mounting hole 405.

[0050] During installation, first put the spring 407 into the fourth installation hole 305, then insert the positioning rod 406 from the side of the fourth installation hole 305, and the connecting section 4061 of the positioning rod 406 passes through the fourth installation hole 305 and enters the third installation hole 304. At this time, the spring 407 abuts against the limiting step 307 and the end face of the insertion section 4062. Press the insertion section 4062 to make the second pin hole 4063 of the connecting section 4061 exposed from the third installation hole 304 and enter the second installation hole 405 of the handle assembly, insert the pin 408, so that the handle assembly is connected with the positioning rod 406, and then release the hand pressing the insertion section 4062. The handle assembly moves toward the third installation hole 304 under the action of the spring 407 until the anti-rotation limiting short column 403 completely enters the fifth installation hole 306, and the axial limiting block 402 abuts against the end face of the third installation hole 304, and the installation is completed. At this time, pulling outward and releasing the hand wheel 401 can make the insertion section 4062 of the positioning rod 406 enter and exit the mounting hole 29 305. In this structure, the axial limit block 402 is used to limit the length of the insertion section 402 extending out of the mounting hole 29, and the anti-rotation limit short column 403 is used to prevent the rotation of the positioning rod after positioning.

[0051] like Figure 8 As shown, the insertion section 4062 of the positioning assembly 4 is used to enter the shaft hole 102 of the fork 1 to achieve positioning. Figure 4 As shown, the positioning assembly 4 of each group of clamp units is arranged on the V-shaped block 3 on one side, which realizes positioning while preventing the shift fork 1 from moving to the side where the positioning assembly 4 is arranged. However, since the other side is not provided with the positioning assembly 4, it may move to that side. As an improvement, this embodiment also includes a limit rod 6, which is against the end face of the shift fork handle shaft to prevent the shift fork 1 from moving to the other side. Figure 2 As shown, in this embodiment, the two groups of clamp units share a limiting rod 6, and the limiting rod 6 is located between the two groups of clamp units.

[0052] like Figure 8 As shown, the limit rod 6 includes a plug section 601, an external thread section 602 and a limit section 603 from bottom to top. The base plate 2 is provided with a mounting hole 6 203. The plug section 601 of the limit rod 6 is inserted into the mounting hole 6 203 with interference fit. The limit section 603 is used to abut against the end face of the handle shaft 103 of the fork 1 to ensure the accurate length of the workpiece. The external thread section 602 is provided to facilitate the replacement of the positioning rod 406. Since the limit rod 6 is interference fitted on the base plate 2 and the limit rod 6 is a metal round rod, it is difficult to clamp and pull out. After the external thread section 602 is provided, a special pulling tool can be used. When pulling, the threaded sleeve of the pulled workpiece is threadedly connected with the external thread section 602, and then force is applied upward to pull, so that the limit rod 6 can be removed.

[0053] The use process of the clamp is as follows: loosen the special pressure plate 503, insert the fork 1, place the handle shafts 103 on both sides of the fork 1 in the V-shaped grooves 301 on both sides, pull the handwheel 401, so that the positioning rod 406 enters the shaft hole 102 on one side of the fork 1, and the shaft end face of the fork 1 on the other side is abutted against the limit rod 6, screw in the special nut 502, and apply downward pressure to the special pressure plate 503, so that the special pressure plate 503 presses the fork 1 tightly in the V-shaped groove 301, and then the cutting and milling process can be carried out.

[0054] The above embodiments are only used to explain the concept of the present invention, rather than to limit the protection of the rights of the present invention. Any non-substantial changes to the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center, comprising a base plate, characterized in that: A plurality of groups of fixture units are installed on the bottom plate, each group of fixture units includes two symmetrically arranged V-shaped blocks, a pressure plate assembly corresponding to the V-shaped blocks one by one, and a positioning assembly located on one side of the V-shaped blocks; The bottom surface of the V-shaped block is fixed to the bottom plate, and the top surface is provided with a V-shaped groove for placing the fork handle shaft; The positioning assembly is used to position the shift fork; The pressing plate assembly is used to press down the shift fork handle shaft and fix it on the V-block.

2. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 1, characterized in that: The base plate is provided with a keyway and a screw hole, the V-shaped block is provided with a mounting hole corresponding to the screw hole and a key with a clearance fit with the keyway, and the V-shaped block is fixedly connected to the base plate through the key and bolts.

3. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 2, characterized in that: The keyway 1 is an oblong hole type and is arranged along the axial direction of the fork. Each keyway 1 is equipped with several groups of screw holes 1, and several groups of screw holes 1 are arranged along the length direction of the keyway 1, and the two screw holes of each group of screw holes 1 are respectively arranged on both sides of the width direction of the keyway 1.

4. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 1, characterized in that: The positioning assembly includes a handle assembly, a positioning rod, a pin and a spring; The positioning rod comprises an inserting section and a connecting section, and the diameter of the inserting section is larger than the diameter of the connecting section; The handle assembly includes a hand wheel and a limiting part, the limiting part includes an axial limiting block and an anti-rotation limiting short column, one side of the axial limiting block is fixed to the anti-rotation limiting short column, and the other side is fixed to the hand wheel, a pin hole 1 is provided on the axial limiting block, a pin hole 2 corresponding to the pin hole 1 is provided on the insertion section, a mounting hole 2 for inserting the connecting section is provided on the axial limiting block, the mounting hole 2 is connected to the pin hole 1, and the pin shaft can be inserted into the pin hole 1 and the pin hole 2; The V-shaped block is provided with a mounting hole 3 matching the insertion section, a mounting hole 4 matching the connection section, and a mounting hole 5 matching the anti-rotation limiting short column. The mounting hole 3 and the mounting hole 4 are coaxial and interpenetrating. The cross-sectional dimension of the mounting hole 3 is smaller than the cross-sectional dimension of the axial limiting block. A limiting step is formed at the junction of the mounting hole three and the mounting hole four, the spring is arranged in the mounting hole four, and the two ends are respectively against the limiting step and the end surface of the insertion section; when the spring is compressed, the insertion section is located in the mounting hole four, and when the spring is stretched, the insertion section is exposed from the mounting hole four.

5. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 1, characterized in that: The pressure plate assembly includes a special screw, two special nuts and a special pressure plate. The base plate is provided with a special screw hole corresponding to the special screw. After the special screw is screwed into the special screw hole, one of the special nuts is screwed to the bottom of the special screw and tightens the base plate. The special pressure plate is slidably connected to the special screw and is located above the V-block. It is used to press down the fork handle shaft placed in the V-groove. The other special nut is located above the special pressure plate. After the special screw is screwed in, downward pressure is applied to the special pressure plate.

6. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 1, characterized in that: It comprises a limiting rod, which is fixed on the bottom plate and is located on one or both sides of the axial direction of the clamp unit and is used to abut against the end surface of the fork handle shaft.

7. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 6, characterized in that: The limit rod includes a connecting section and a limiting section. The base plate is provided with a mounting hole six. The connecting section of the limit rod is inserted into the mounting hole six with an interference fit, and the limiting section is used to abut against the end surface of the fork handle shaft.

8. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 7, characterized in that: The limiting rod comprises an external thread section located between the connecting section and the limiting section.

9. A special fixture for milling the keyway on the fork handle shaft of a vertical machining center as claimed in claim 6, characterized in that: At least two groups of clamp units are included, and the two groups of clamp units share a limiting rod. The two groups of clamp units are arranged side by side, and the limiting rod is located between the two groups of clamp units.

Images