A tapping machine for fastener production

Abstract

The utility model belongs to mechanical manufacturing equipment technical field, concretely relates to a tapping machine for fastener production. Including spindle, still include the tap anti -rotation clamping mechanism of installation in spindle, it includes: chuck body, with spindle fixed connection, its inside front end is equipped with the taper hole and the limiting step located taper hole rear; Elastic collet, install in the taper hole, be used for clamping tap; Locking nut, with chuck body front end screw connection, when screwing up push elastic collet contraction clamping; Anti -rotation positioning sleeve, through the front end of guiding lock structure slip -on chuck body and limit its circumferential rotation, anti -rotation positioning sleeve has axial limiting portion, when sliding into in place and limiting step abut, and anti -rotation positioning sleeve center is equipped with the anti -rotation hole of cooperation transmission torque with tap tail part, annular buffer, be equipped with between the rear end of axial limiting portion and elastic collet. The utility model through above -mentioned technical scheme can obtain a tapping machine for fastener production that can reliably prevent tap circumferential slip.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical manufacturing equipment technology, specifically relating to a tapping machine for fastener production. Background Technology

[0002] Tapping machines for fastener production are specialized equipment used to process internal threads on fasteners such as nuts and sleeves. They use a spindle to drive the tap to rotate and feed axially, cutting internal threads in the workpiece hole.

[0003] In existing tap clamping mechanisms of tapping machines, to prevent circumferential slippage of the tap under cutting torque, a threaded screw-in stop is typically installed within the chuck body. The stop has a square hole at its front end that engages with the square corner of the tap's tail to transmit torque. However, the threaded fit inherently contains clearance. Under high torque or high-frequency alternating cutting conditions, the stop is prone to circumferential deflection, leading to tap slippage, damaged nut threads, or even tap breakage, severely impacting product yield and production efficiency in batch processing. Therefore, there is an urgent need for a tapping machine for fastener production that can reliably prevent circumferential slippage of the tap. Utility Model Content

[0004] This invention solves the problems mentioned in the background art by setting an anti-rotation positioning sleeve and sliding it on the front end of the chuck body through a guide locking structure to restrict its circumferential rotation, thereby achieving reliable anti-rotation of the tap.

[0005] The technical solution of this utility model is implemented as follows: a tapping machine for fastener production includes a spindle and a tap anti-rotation clamping mechanism mounted on the spindle, which includes: The chuck body is fixedly connected to the main shaft, and its front end is provided with a tapered hole and a limiting step located behind the tapered hole; A flexible collet is installed inside the tapered hole to hold the tap; A locking nut is threaded to the front end of the chuck body, and when tightened, it pushes the elastic collet to reduce its diameter and clamp. The anti-rotation positioning sleeve is slidably mounted on the front end of the chuck body through a guide locking structure to restrict its circumferential rotation. The anti-rotation positioning sleeve has an axial limiting part that abuts against the limiting step when it slides into place. The anti-rotation positioning sleeve also has an anti-rotation hole at its center that cooperates with the tail of the tap to transmit torque. An annular buffer is clamped between the axial limiting part and the rear end of the elastic collet.

[0006] The present invention is further configured such that the guide locking structure includes a sliding groove formed on the inner wall of the chuck body and a sliding rib provided on the outer wall of the anti-rotation positioning sleeve, wherein the sliding rib is fitted into the sliding groove.

[0007] The present invention is further configured such that the cross-sections of the sliding rib and the sliding groove are both dovetail-shaped.

[0008] The present invention is further configured such that the axial limiting part is an annular limiting plate located at the front end of the anti-rotation positioning sleeve.

[0009] The present invention is further configured such that the inner wall of the front end of the locking nut is provided with an annular abutment platform, and the outer wall of the front end of the elastic collet is provided with an annular abutment groove.

[0010] The present invention is further configured such that the annular buffer is a polyurethane buffer gasket.

[0011] The present invention is further configured such that the anti-rotation hole is a square hole, and an inlet cone is provided at one end facing the elastic collet.

[0012] By adopting the above technical solution, the beneficial effects that this utility model can achieve are: 1. By using the guide locking structure between the anti-rotation positioning sleeve and the chuck body to restrict the circumferential rotation of the anti-rotation positioning sleeve, the four corners of the tap tail can stably cooperate with the anti-rotation hole to transmit torque, thereby improving the reliability of tap anti-rotation.

[0013] 2. By using the anti-rotation positioning sleeve to slide onto the front end of the chuck body with a guide locking structure, the axial straight insertion of the anti-rotation positioning sleeve is achieved, which improves the tap replacement efficiency.

[0014] 3. An annular buffer, clamped between the axial limiting part and the rear end of the elastic collet, provides axial preload, preventing the anti-rotation positioning sleeve from loosening and absorbing axial impact, thus improving machining stability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure; Figure 3 yes Figure 2 A magnified structural diagram of part A; Figure 4 This is an exploded view of this utility model; Figure 5 This is a partial structural schematic diagram of the present invention.

[0016] The attached diagram is labeled as follows: 1. Spindle; 2. Tap; 3. Chuck body; 4. Tapered hole; 5. Limiting step; 6. Elastic collet; 7. Locking nut; 8. Anti-rotation positioning sleeve; 9. Annular limiting plate; 10. Anti-rotation hole; 11. Annular buffer; 12. Slide groove; 13. Slide rib; 14. Annular abutment platform; 15. Annular abutment groove; 16. Inlet tapered hole. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-5 : Example: This embodiment provides a tapping machine for fastener production, including a spindle 1 and a tap 2 anti-rotation clamping mechanism mounted on the spindle 1, which includes: The chuck body 3 is fixedly connected to the main shaft 1, and its front end is provided with a tapered hole 4 and a limiting step 5 located behind the tapered hole 4; The elastic collet 6 is installed in the tapered hole 4 and is used to hold the tap 2; The locking nut 7 is threaded to the front end of the chuck body 3. When tightened, it pushes the elastic collet 6 to reduce its diameter and clamp. The anti-rotation positioning sleeve 8 is slidably mounted on the front end of the chuck body 3 through a guide locking structure and restricts its circumferential rotation. The anti-rotation positioning sleeve 8 has an axial limiting part, which abuts against the limiting step 5 when it slides into place. The center of the anti-rotation positioning sleeve 8 is provided with an anti-rotation hole 10 that cooperates with the tail of the tap 2 to transmit torque. An annular buffer 11 is clamped between the axial limiting part and the rear end of the elastic collet 6.

[0018] This embodiment relates to the technical field of fastener processing equipment, specifically a tapping machine for mass production of fasteners, especially suitable for multi-station rotary nut tapping equipment, used to achieve stable clamping and circumferential anti-rotation of tap 2. The structure, fit relationship and working process of each component are described in detail below.

[0019] The spindle 1 is the rotary power output component of the tapping machine. It is located at the power output end of the tapping station of the tapping machine. Its function is to transmit the rotational torque of the equipment drive mechanism outward, so as to drive the clamping mechanism at the front end and the tap 2 to rotate synchronously to complete the thread cutting operation. The front end of the spindle 1 is the coaxial mounting reference end. The rear end of the chuck body 3 is provided with a mounting taper shank. The front end of the spindle 1 is provided with a matching mounting taper hole 4. The taper shank and the taper hole 4 are fitted together to achieve coaxial positioning. At the same time, the rear end of the chuck body 3 and the end face of the spindle 1 are locked and fixed by multiple sets of circumferentially distributed locking bolts. A flat key is also provided between the two to transmit the rotational torque. After assembly, there is no relative rotation, so as to realize the synchronous transmission of torque.

[0020] The chuck body 3 is the base bearing component of the entire clamping mechanism. It has an axially continuous cylindrical structure. Its rear end is coaxially locked to the main shaft 1 via a tapered shank and a flat key, and rotates synchronously with the main shaft 1. The internal cavity of the chuck body 3 has a tapered hole 4 and a limiting step 5 arranged sequentially from front to back along the axial direction. The inner diameter of the tapered hole 4 gradually decreases from the front end to the rear, and the inner wall forms a tapered fitting surface to accommodate and adapt to the outer contour of the elastic collet 6. The limiting step 5 is an annular vertical end face formed behind the tapered hole 4 due to the reduction in inner diameter. Its function is to limit the backward movement of the anti-rotation positioning sleeve 8. The outer wall of the front end of the chuck body 3 The chuck body 3 has a continuous external thread structure for threaded engagement with the locking nut 7. The inner wall of the chuck body 3 has an axially oriented groove 12. The groove 12 extends from the front end face of the body to the front end face of the limiting step 5. The function of the groove 12 is to cooperate with the anti-rotation positioning sleeve 8 to restrict the circumferential rotation of the anti-rotation positioning sleeve 8. An inwardly tapering stop is provided at the entrance of the groove 12 at the front end of the chuck body 3. The inner diameter of the stop is smaller than the maximum outer diameter of the sliding rib 13 on the outer wall of the anti-rotation positioning sleeve 8. After the anti-rotation positioning sleeve 8 is completely slid into the groove 12, the stop prevents the sliding rib 13 from dislodging forward, forming a bidirectional axial limit with the rear limiting step 5.

[0021] The elastic collet 6 is a radial clamping component for the cylindrical shank of the tap 2. It is an overall conical cylindrical structure with axial slots and has radial elastic deformation capability. It is assembled in the conical hole 4 inside the collet body 3, and the outer conical surface fits against the inner wall of the conical hole 4 of the collet body 3. The elastic collet 6 has an axially penetrating tool receiving hole for inserting the cylindrical shank of the tap 2. When the elastic collet 6 is subjected to axial thrust and moves backward along the conical hole 4, the inner wall of the conical hole 4 will apply radial extrusion force to the elastic collet 6, causing the inner diameter of the elastic collet 6 to shrink, thereby clamping the cylindrical shank of the tap 2 inside and achieving radial fixation of the tap 2. The outer wall of the front end of the elastic collet 6 has a concave annular abutment groove 15 for receiving the axial thrust transmitted by the locking nut 7. The rear end face of the elastic collet 6 forms an end face extrusion contact with the front end face of the annular buffer 11. When the elastic collet 6 moves backward to clamp the tap 2, it will simultaneously extrude the annular buffer 11 to cause it to undergo elastic deformation.

[0022] The locking nut 7 is an operating component that drives the elastic collet 6 to complete the clamping action. It is an annular sleeve structure with internal threads, which is fitted on the outer front end of the collet body 3. The internal threads machined on the inner wall mesh with the external threads at the front end of the collet body 3. It can move back and forth along the axial direction of the collet body 3 by rotation. The inner wall of the front end of the locking nut 7 protrudes inward to form an annular abutment platform. The abutment platform is embedded in the annular abutment groove 15 at the front end of the elastic collet 6. The two form an axial locking fit. When the locking nut 7 is rotated to move backward along the collet body 3, the abutment platform will push the elastic collet 6 to move backward synchronously, thereby causing the elastic collet 6 to be squeezed by the tapered hole 4 to produce a diameter reduction clamping action.

[0023] The anti-rotation positioning sleeve 8 is the core functional component for preventing the tap 2 from rotating circumferentially. It is an axially continuous sleeve structure, which slides inward axially from the front opening of the chuck body 3 to complete assembly. The outer wall of the anti-rotation positioning sleeve 8 has outwardly protruding sliding ribs 13 along the axial direction. The cross-sectional shape of the sliding ribs 13 matches the cross-sectional shape of the sliding grooves 12 on the inner wall of the chuck body 3. The sliding ribs 13 are embedded in the sliding grooves 12 to form a sliding fit. This fit structure allows the anti-rotation positioning sleeve 8 to move only along the axial direction of the chuck body 3, preventing circumferential rotation relative to the chuck body 3. In this embodiment, the cross-sections of both the sliding rib 13 and the sliding groove 12 are designed as dovetail shapes, and the two fit together to form a fit. In addition to restricting circumferential rotation, they can also restrict the radial movement of the anti-rotation positioning sleeve 8, improving the coaxiality and locking stability of the assembly. The front end of the anti-rotation positioning sleeve 8 is provided with an axial limiting part, which is an annular limiting plate 9 extending outward along the outer wall of the anti-rotation positioning sleeve 8. When the anti-rotation positioning sleeve 8 slides backward to the limit position, the rear end face of the annular limiting plate 9 abuts against the front end face of the limiting step 5 inside the chuck body 3, thereby restricting the anti-rotation positioning sleeve. 8 continues to move backward, completing the axial positioning to the rearward side; the annular limiting plate 9 of the anti-rotation positioning sleeve 8 has an annular groove on its front end face, and the annular buffer 11 is embedded in the groove as a whole. The inner and outer annular walls of the groove form a radial limit on the annular buffer 11, preventing the buffer from radially shifting under rotation conditions; the center of the anti-rotation positioning sleeve 8 has an axially penetrating anti-rotation hole 10. In one embodiment, the anti-rotation hole 10 is a square hole, and its inner contour shape is adapted to the square outer contour shape of the tail of the tap 2. After the tap 2 is inserted from the front end, its tail extends... Inside the anti-rotation hole 10, the hole wall fits against the side of the tail of the tap 2 to transmit torque and prevent the tap 2 from slipping circumferentially relative to the clamping mechanism. The anti-rotation hole 10 has an inlet cone at the front opening facing the elastic collet 6. The inner diameter of the inlet cone gradually narrows from the front end to the rear, forming a trumpet-shaped guide slope structure. During the clamping of the tap 2, the tail of the tap 2 can automatically slide into the square anti-rotation hole 10 along the slope of the inlet cone. The fit between the tail of the tap 2 and the anti-rotation hole 10 can be completed without manual precise alignment, reducing the difficulty of the clamping operation.

[0024] The annular buffer 11 is an elastic component that achieves axial preload and impact buffering. It is a continuous annular sheet structure and is embedded in the annular groove at the front end of the annular limiting plate 9. It is clamped between the front end face of the annular limiting plate 9 and the rear end face of the elastic collet 6 and is in a compressed state after assembly. When the elastic collet 6 moves backward to complete the action of clamping the tap 2, its rear end face will squeeze the annular buffer 11, causing the buffer to undergo elastic deformation. The elastic force generated by the deformation acts forward on the anti-rotation positioning sleeve 8, so that the annular limiting plate 9 continues to fit on the limiting step 5, eliminating assembly gaps and preventing the anti-rotation positioning sleeve 8 from axial movement caused by vibration during processing. On the other hand, it acts on the elastic collet 6 to absorb the axial impact load generated during the cutting process of the tap 2 and reduce the rigid collision between the tail of the tap 2 and the inner wall of the anti-rotation hole 10. In one embodiment, the annular buffer 11 is a buffer washer made of polyurethane material, which has the characteristic of being resistant to cutting oil corrosion and can be adapted to the use environment of long-term contact with cutting oil during tapping operations.

[0025] The assembly process of the tapping machine clamping mechanism is as follows: First, align the sliding rib 13 of the anti-rotation positioning sleeve 8 with the sliding groove 12 on the inner wall of the chuck body 3, and push it inward from the front opening of the chuck body 3. After the sliding rib 13 passes through the inlet stop of the sliding groove 12, it continues to slide backward until the annular limiting plate 9 of the anti-rotation positioning sleeve 8 abuts against the limiting step 5. The inlet stop of the sliding groove 12, together with the limiting step 5, realizes the bidirectional limiting of the anti-rotation positioning sleeve 8, completing the pre-assembly of the anti-rotation positioning sleeve 8; then, embed the annular buffer 11 into the annular limiting plate 9. Within the annular groove at the front end, the radial displacement of the buffer component is restricted by the inner wall of the groove, allowing it to stably adhere to the front end face of the annular limiting plate 9. Then, the elastic collet 6 is inserted from the front end of the chuck body 3 into the tapered hole 4, so that the rear end face of the elastic collet 6 contacts the front end face of the annular buffer component 11. Finally, the locking nut 7 is fitted onto the front end of the chuck body 3, so that the abutment platform of the locking nut 7 is embedded in the abutment groove of the elastic collet 6. The locking nut 7 is rotated to move backward along the external thread of the chuck body 3, initially pushing the elastic collet 6 to be positioned backward.

[0026] When clamping tap 2, insert tap 2 into the front opening of locking nut 7. The cylindrical shank of tap 2 enters the tool receiving hole of elastic collet 6. The tail of tap 2 automatically slides into the anti-rotation hole 10 of the square structure along the guide slope of the inlet taper. There is no need to manually align the square contour. Continue to tighten locking nut 7. Locking nut 7 moves backward continuously due to thread engagement. The abutment platform pushes elastic collet 6 backward to squeeze the annular buffer 11. Elastic collet 6 is squeezed radially by the taper hole 4 of collet body 3, which clamps the cylindrical shank of tap 2. At the same time, the annular buffer 11 is continuously compressed to generate bidirectional elastic preload, thus completing the overall clamping of tap 2.

[0027] During tapping operations, the spindle 1 drives the chuck body 3 to rotate as a whole by the conical surface contact and the key transmission. The chuck body 3 transmits the rotational torque to the anti-rotation positioning sleeve 8 through the engagement of the sliding groove 12 and the sliding rib 13. Then, the torque is transmitted to the tail of the tap 2 through the contact surface of the square anti-rotation hole 10. At the same time, the elastic collet 6 holds the cylindrical shank of the tap 2 and transmits the rotational power synchronously. The dual torque transmission path ensures that the tap 2 rotates synchronously with the spindle 1 and does not slip in the circumferential direction. During the cutting process, the axial impact generated by the feed of the tap 2 and chip jamming is transmitted to the elastic collet 6 and the annular buffer 11 in sequence. The annular buffer 11 in the compressed state absorbs and reduces the impact load, avoiding the impact from acting directly on the anti-rotation positioning sleeve 8 and the tail of the tap 2, and reducing the wear caused by the rigid collision between the two.

[0028] This structure replaces the traditional screw-in stop structure with a guide locking structure that slides and engages with the sliding groove 12 and the sliding rib 13, eliminating the risk of circumferential deflection caused by the thread fit clearance and improving the reliability of tap 2 anti-rotation. The anti-rotation positioning sleeve 8 adopts a front-end sliding assembly method, which can be disassembled and assembled without rotation or screwing, making it easy to replace corresponding components of different specifications and adapting to the scenario of frequently changing the specifications of tap 2 in fastener production. The inlet stop of the sliding groove 12, together with the rear end limiting step 5, forms a bidirectional axial limit to prevent the anti-rotation positioning sleeve 8 from coming off before and after assembly and operation. The annular groove limits the radial displacement of the buffer component, ensuring the continuous stability of the buffer and pre-tightening functions. The annular buffer component 11 simultaneously realizes the axial pre-tightening of the anti-rotation positioning sleeve 8 and the buffering of cutting impact. The overall structure is suitable for the operation conditions of batch continuous tapping of fasteners.

[0029] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made based on the structure, shape, and principle of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A tapping machine for fastener production, comprising a spindle (1), characterized in that, It also includes an anti-rotation clamping mechanism mounted on the spindle (1) and used for the tap (2), which includes: The chuck body (3) is fixedly connected to the main shaft (1), and its front end is provided with a tapered hole (4) and a limiting step (5) located behind the tapered hole (4). The elastic collet (6) is installed in the tapered hole (4) and is used to hold the tap (2). The locking nut (7) is threaded to the front end of the chuck body (3), and when tightened, it pushes the elastic collet (6) to reduce its diameter and clamp. The anti-rotation positioning sleeve (8) is slidably mounted on the front end of the chuck body (3) through a guide locking structure and restricts its circumferential rotation. The anti-rotation positioning sleeve (8) has an axial limiting part, which abuts against the limiting step (5) when it slides into place. The center of the anti-rotation positioning sleeve (8) is provided with an anti-rotation hole (10) that cooperates with the tail of the tap (2) to transmit torque. An annular buffer (11) is clamped between the axial limiting part and the rear end of the elastic collet (6).

2. The tapping machine for fastener production according to claim 1, wherein The guide locking structure includes a groove (12) formed on the inner wall of the chuck body (3) and a rib (13) provided on the outer wall of the anti-rotation positioning sleeve (8), wherein the rib (13) is fitted into the groove (12).

3. The tapping machine for fastener production according to claim 2, wherein The cross-sections of the sliding rib (13) and the sliding groove (12) are both dovetail-shaped.

4. A tapping machine for fastener production according to claim 1, characterized in that, The axial limiting part is an annular limiting plate (9) located at the front end of the anti-rotation positioning sleeve (8).

5. The tapping machine for fastener production according to claim 1, wherein The locking nut (7) has an annular abutment platform (14) on its front inner wall, and the elastic collet (6) has an annular abutment groove (15) on its front outer wall.

6. The tapping machine for fastener production according to claim 1, wherein The annular buffer (11) is a polyurethane buffer gasket.

7. The tapping machine for fastener production according to claim 1, wherein The anti-rotation hole (10) is a square hole, and an inlet cone is provided at one end facing the elastic collet (6).

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