Limiting tool for machining key groove in workpiece

By designing a base and rotating disk assembly for the limiting fixture, and using screws and rollers to limit the broach runout, the instability problem of the broach when machining the keyway inside the workpiece is solved, and the consistency of the keyway depth and the improvement of machining accuracy are achieved.

CN223863341UActive Publication Date: 2026-02-03JIAXING BEIFEITE SPROCKET MFG CO LTD
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Patent Information

Application Number
CN202423245132.9
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-12-26
Publication Date
2026-02-03
Estimated Expiration
2034-12-26

AI Technical Summary

Technical Problem

When machining the keyway inside a workpiece, the broach is prone to jumping due to the instability of the moving mechanism, which affects the machining accuracy.

Method used

A limiting fixture was designed, including components such as a base, a rotating disk, a mounting base, a clamping block, a connecting block, a screw, and rollers. The screw drives the slider to make the rollers contact the broach, limiting the broach's runout and ensuring machining stability.

Benefits of technology

It effectively prevents the broach from jumping during machining, ensures consistent keyway depth, avoids workpiece machining errors, and improves machining accuracy.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a limiting tool for processing an inner key groove of a workpiece, which comprises a mounting seat, a tool outlet hole is arranged on the mounting seat, a clamping block is fixedly connected with one bottom surface of the mounting seat, a connecting column is integrally formed on the clamping block, the tool outlet hole of the mounting seat penetrates through the connecting column, and a connecting block is fixedly connected with the side wall of the mounting seat. The upper portion of the connecting block is in threaded connection with a vertical screw rod, the end of the screw rod is located in the polygonal limiting groove, a sliding block is embedded in the polygonal limiting groove, the sliding block is aligned with the clamping block on the other face of the mounting base, one end of the sliding block is rotationally connected with the end of the screw rod, and the other end of the sliding block is rotationally connected with a rolling wheel. The rolling wheel rotates on the vertical face and is located below the connecting block. According to the utility model, the workpiece is fixed on the mounting seat, and then the broach penetrates through the workpiece and the mounting seat, so that the roller is in contact with the upper part of the section with the largest sawteeth on the broach, and the broach is limited by the roller and cannot bounce upwards, so that the processing error of the workpiece is avoided.
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Description

Technical Field

[0001] This utility model relates to the field of workpiece internal keyway machining technology, and in particular to a limiting tooling for workpiece internal keyway machining. Background Technology

[0002] A keyway is a groove machined into a shaft or hole to fit a key, used to mount the key and transmit torque.

[0003] A keyway broaching machine is typically used when machining keyways. During operation, the workpiece is fixed on the machine, and the moving mechanism on the machine drives the keyway broach through the hole in the workpiece. The serrations of the keyway broach pass through the hole from small to large, thus exerting a force on the inner wall of the hole, thereby grinding a keyway on the inner wall. However, during machining, the hole in the workpiece is placed vertically, and the keyway broach passes horizontally through the hole. Because the keyway broach is relatively long, coupled with the force between the broach and the workpiece, the moving mechanism cannot stably drive the keyway broach through the hole, and the broach will bounce upward, affecting the machining of the workpiece. Utility Model Content

[0004] The purpose of this invention is to provide a limiting fixture for machining keyways in workpieces, which has the advantage of preventing the broach from running out of space during keyway machining.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0006] A limiting fixture for machining keyways in a workpiece includes a base with a rotating disk at one end. Both the rotating disk and the end of the base have aligning mounting holes. A groove is formed on the surface of the rotating disk, and the mounting holes on the rotating disk are located within the groove. The fixture also includes a limiting mechanism comprising a mounting base with a tool outlet hole at its center. A locking block is fixedly connected to one bottom surface of the mounting base. A connecting post is integrally formed on the surface of the locking block. The tool outlet hole of the mounting base passes through the connecting post, and the connecting post passes into the mounting holes at the ends of the rotating disk and the base. The locking block is located within the groove. The mounting base is in contact with the surface of the rotating disk and is fixed to the rotating disk by a connector. The side of the mounting base away from the rotating disk has a groove and a connecting block. One part of the connecting block is fixedly connected to the side wall of the mounting base, and the other part of the connecting block is free. The free part of the connecting block has a polygonal limiting groove, and a vertical screw is threaded to the upper part of the connecting block. The end of the screw is located in the polygonal limiting groove, and a slider is embedded in the polygonal limiting groove. The slider is aligned with a locking block on the other side of the mounting base. One end of the slider is rotatably connected to the end of the screw, and the other end is rotatably connected to a roller. The roller rotates on the vertical plane and is located below the connecting block.

[0007] Using the above technical solution, first, the smaller serrated part of the broach is passed through the tool outlet hole of the mounting base. The broach is pulled so that the section with the largest serrated tooth on the broach is moved to the tool outlet hole of the mounting base. The screw on the connecting block is turned, and the screw pushes the slider to move vertically. The slider drives the rotating wheel to contact the upper surface of the largest serrated tooth of the broach. Then, the broach is removed from the mounting base. Next, the workpiece is placed into the groove of the mounting base, aligning the round hole of the workpiece with the tool outlet hole of the mounting base. The workpiece is fixed to the mounting base using a fastener. Then, one end of the broach is passed through the round hole of the workpiece, the tool outlet hole of the mounting base, and finally through the mounting base. The broach is fixed to the base end, and the moving mechanism on the base pulls the broach along the workpiece's circular hole. The broach's serrations, from small to large, pass through the workpiece's circular hole, exerting force on the inner wall of the hole, thus grinding a keyway on the inner wall. The workpiece debris generated during machining falls into the collection box. When the largest serration on the broach moves to the workpiece's circular hole, the broach contacts the roller above it. The movement of the broach causes the roller to rotate. The broach is restricted by the roller and will not jump upwards, thus preventing the keyway depth from exceeding the height of the largest serration on the broach and causing workpiece machining errors.

[0008] Preferably, the connecting component is a bolt, the surface of the mounting base has two symmetrical through holes, the bottom surface of the slot of the rotating disk has a threaded hole corresponding to the through holes, and the two through holes of the mounting base are respectively threaded through the bolts, which are threaded to the rotating disk through the threaded hole on the bottom surface of the slot.

[0009] Using the above technical solution, by tightening bolt one on the rotating disk, the tail of bolt one presses against the mounting seat, thereby fixing the mounting seat on the rotating disk. Similarly, by unscrewing bolt one from the rotating disk, the mounting seat can be removed from the rotating disk.

[0010] Preferably, a collection box is fixedly connected to the end of the base, and the collection box is located below the rotating disk.

[0011] Using the above technical solution, the processed workpiece debris and the finished workpiece fall into the collection box.

[0012] Preferably, a support plate is fixedly connected to the side of the collection box opposite to the rotating disk, and a horizontal rotating shaft is rotatably connected to the upper part of the support plate.

[0013] Using the above technical solution, the broach is placed on the rotating shaft of the support plate, and then one end of the broach is passed through the round hole of the workpiece, so that the end of the broach passing through the workpiece is fixedly connected to the base. The moving mechanism pulls the broach along the round hole of the workpiece. The moving broach drives the rotating shaft to rotate, and the rotating shaft supports the broach to prevent one end of the broach from being unbalanced and causing the broach to deflect.

[0014] Preferably, a lubricating fluid delivery pipe is fixedly connected to the side of the base.

[0015] By adopting the above technical solution, lubricant can be sprayed onto the workpiece and broach through the delivery pipe during workpiece processing, thereby improving the processing effect. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the embodiment;

[0017] Figure 2 This is a side view of an embodiment;

[0018] Figure 3 This is a front view of an embodiment;

[0019] Figure 4 This is a top view of an embodiment;

[0020] Figure 5 This is a schematic diagram of the overall structure of the limit fixture and the rotating disk;

[0021] Figure 6 This is an overall schematic diagram of the limiting fixture from another perspective;

[0022] Figure 7 This is a sectional view of the workpiece along the AA direction.

[0023] Reference numerals in the attached diagram: 1. Base; 2. Rotating disc; 3. Mounting base; 4. Clamping block; 5. Connecting column; 6. Connecting block; 7. Screw; 8. Sliding block; 9. Roller; 10. Bolt 1; 11. Bolt 2; 12. Pressure block; 13. Nut; 14. Bolt 3; 15. Collection box; 16. Rotating shaft; 17. Conveying pipe. Detailed Implementation

[0024] The following description is merely a preferred embodiment of this utility model, and the scope of protection is not limited to this embodiment. All technical solutions falling within the scope of this utility model should be considered within the protection scope of this utility model. It should also be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

[0025] See Figure 1 , Figure 5 and Figure 6A limiting fixture for machining keyways in workpieces includes a base 1 with a moving mechanism mounted on top, and a broach installed on the moving mechanism. A rotating disk 2 is located at one end of the base 1. Both the end of the base 1 and the rotating disk 2 have mounting block holes. A slot is formed on the surface of the rotating disk 2, and the mounting hole of the rotating disk 2 is located in the slot and at the center of the rotating disk 2, through which the broach passes. The fixture also includes a mounting base 3 with a tool exit hole at its center. A locking block 4 corresponding to the slot of the rotating disk 2 is integrally formed on one bottom surface of the mounting base 3. A connecting post 5 corresponding to the mounting hole of the chuck is integrally formed on the surface of the locking block 4. The tool exit hole of the mounting base 3 passes through the connecting post 5. The connecting post 5 passes into the mounting holes at the end of the base 1 and the rotating disk 2. The locking block 4 is located in the slot, the mounting base 3 is in contact with the surface of the rotating disk 2, and the tool exit hole of the mounting base 3 is aligned with the mounting hole, through which the broach passes. The mounting base 3 has a groove on the side away from the rotating disk 2. The surface of the mounting base 3 has two symmetrical through holes. The bottom surface of the slot of the rotating disk 2 has a threaded hole corresponding to the through hole. Bolt 10 is inserted into the two through holes of the mounting base 3 respectively. Bolt 10 is threaded to the rotating disk 2 through the threaded hole on the bottom surface of the slot, thereby fixing the mounting base 3 and the rotating disk 2.

[0026] Figure 2 , Figure 5 and Figure 7 A connecting block 6 is bolted to the side wall of the mounting base 3. A portion of the connecting block 6 extends to the outside of the side wall of the mounting base 3. The portion of the connecting block 6 located on the outside of the side wall of the mounting base 3 has a polygonal limiting groove. A vertical screw 7 is threaded to the upper part of the connecting block 6, and the end of the screw 7 is located in the polygonal limiting groove. A slider 8 is embedded in the polygonal limiting groove. The slider 8 is aligned with the locking block 4 on the other side of the mounting base 3. One end of the slider 8 located in the polygonal limiting groove is rotatably connected to the end of the screw 7. The other end of the slider 8 located outside the polygonal limiting groove is rotatably connected to a roller 9. The roller 9 rotates on a vertical plane and is located below the connecting block 6.

[0027] See Figure 3 — Figure 5 Multiple bolts 11 are fixedly connected to the surface of the rotating disk 2. The bolts 11 are perpendicular to the surface of the rotating disk 2. Each bolt 11 has a pressure block 12 through it. Each pressure block 12 has a waist-shaped groove. The bolt 11 passes through the waist-shaped groove of the pressure block 12. The pressure block 12 can slide and rotate on the bolt 11. The bolt 11 is threaded with a nut 13. The pressure block 12 is located between the nut 13 and the rotating disk 2. Near its end, the pressure block 12 is threaded with a bolt 14. The end of the bolt 14 contacts the surface of the rotating disk 2.

[0028] See Figure 1 and Figure 2A collection box 15 is fixedly connected to one end of the base 1. The collection box 15 is located below the rotating disk 2. A support plate is fixedly connected to the side of the collection box 15 opposite to the rotating disk 2. A horizontal rotating shaft 16 is rotatably connected to the upper part of the support plate. A lubricating fluid delivery pipe 17 is fixedly connected to the side of the base 1. The delivery pipe 17 includes a support pipe. One end of the support pipe is divided into two branches. Each branch is connected to a hose. The outlet of the hose is close to the center of the rotating disk 2. The other end is connected to a rubber tube, which is connected to a water pump.

[0029] Working principle: First, pass the smaller part of the broach through the blade outlet hole of the mounting base 3, pull the broach so that the part with the largest serration on the broach moves to the blade outlet hole of the mounting base 3, turn the screw 7 on the connecting block 6, the screw 7 pushes the slider 8 to move vertically, and the slider 8 drives the rotating wheel to contact the upper surface of the largest serration of the broach.

[0030] Remove the broach from the mounting base 3, then place the workpiece into the groove of the mounting base 3, aligning the round hole of the workpiece with the tool outlet hole of the mounting base 3. Adjust the distance between the pressure block 12 and the rotating disk 2 by tightening bolt 3 14. Then rotate and move the pressure block 12 to press the workpiece down. Tighten nut 13 to push the pressure block 12 to press the workpiece firmly, fixing the workpiece on the mounting base 3. Place the broach on the rotating shaft 16 of the support plate. Then, pass one end of the broach through the round hole of the workpiece, the tool outlet hole of the mounting base 3, and finally through the end of the base 1 where the mounting base 3 is located, fixing the broach to the moving mechanism. The moving mechanism pulls the broach along the round hole of the workpiece. The moving broach drives the rotating shaft 16 to rotate, and the rotating shaft 16 supports the broach to prevent one end of the broach from being unbalanced and causing the broach to deflect. The serrations of the broach pass through the round hole of the workpiece from small to large, exerting force on the inner wall of the round hole, thereby grinding a keyway on the inner wall. The workpiece debris generated during processing falls into the collection box 15. When the largest section of the broach's serrations moves to the workpiece's circular hole, the broach contacts the roller 9 above it. The movement of the broach causes the roller 9 to rotate. The broach is restricted by the roller 9 and will not jump upwards, thus preventing the keyway depth from exceeding the height of the broach's largest serration and causing workpiece processing errors.

Claims

1. A limiting fixture for machining a keyway in a workpiece, comprising a base (1), wherein a rotating disk (2) is provided at one end of the base (1), and mounting holes are respectively provided on the rotating disk (2) and the end of the base (1) thereon, and a slot is provided on the surface of the rotating disk (2), wherein the mounting hole of the rotating disk (2) is located in the slot, characterized in that, It also includes a limiting mechanism, which includes a mounting base (3), a knife-out hole at the center of the mounting base (3), a locking block (4) fixedly connected to one bottom surface of the mounting base (3), a connecting post (5) integrally formed on the surface of the locking block (4), the knife-out hole of the mounting base (3) penetrating the connecting post (5), the connecting post (5) penetrating into the mounting holes at the ends of the rotating disk (2) and the base (1), the locking block (4) being located in the slot, the mounting base (3) contacting the surface of the rotating disk (2), the mounting base (3) being fixed to the rotating disk (2) by a connector, a groove being provided on the side of the mounting base (3) away from the rotating disk (2), and also includes a connecting block (6), connecting... One part of the connecting block (6) is fixedly connected to the side wall of the mounting base (3), and the other part of the connecting block (6) is free. The free part of the connecting block (6) is provided with a polygonal limiting groove, and the upper part of the connecting block (6) is threaded with a vertical screw (7). The end of the screw (7) is located in the polygonal limiting groove. The polygonal limiting groove is embedded with a slider (8). The slider (8) is aligned with the locking block (4) on the other side of the mounting base (3). One end of the slider (8) is rotatably connected to the end of the screw (7), and the other end is rotatably connected to a roller (9). The roller (9) rotates on the vertical plane and is located below the connecting block (6). The surface of the rotating disk (2) is provided with a fixing member.

2. The limiting fixture for machining the inner keyway of a workpiece according to claim 1, characterized in that, The connecting component is bolt one (10). The surface of the mounting base (3) is provided with two symmetrical through holes. The bottom surface of the slot of the rotating disk (2) is provided with a threaded hole corresponding to the through hole. Bolt one (10) is inserted into the two through holes of the mounting base (3). Bolt one (10) is threadedly connected to the rotating disk (2) through the threaded hole on the bottom surface of the slot.

3. A limiting fixture for machining an inner keyway of a workpiece according to claim 1, characterized in that, The fasteners include bolt two (11), pressure block (12), nut (13) and bolt three (14). There are multiple bolt two (11) and pressure block (12). Bolt two (11) is fixedly connected to the surface of the rotating disk (2). Each pressure block (12) has a waist-shaped groove. Bolt two (11) passes through the waist-shaped groove of the pressure block (12). The pressure block (12) and bolt two (11) are slidably and rotatably connected. Bolt two (11) is threadedly connected to nut (13). The pressure block (12) is located between nut (13) and rotating disk (2). Bolt three (14) is threadedly connected to the end of pressure block (12). The end of bolt three (14) is in contact with the surface of rotating disk (2).

4. A limiting fixture for machining an inner keyway of a workpiece according to claim 1, characterized in that, A collection box (15) is fixedly connected to the end of the base (1), and the collection box (15) is located below the rotating disk (2).

5. A limiting fixture for machining an inner keyway of a workpiece according to claim 4, characterized in that, The collection box (15) is fixedly connected to a support plate on the side opposite to the rotating disk (2), and a horizontal rotating shaft (16) is rotatably connected to the upper part of the support plate.

6. A limiting fixture for machining an inner keyway of a workpiece according to claim 1, characterized in that, The base (1) has a lubricating fluid delivery pipe (17) fixedly connected to its side.