CN114310409B - Cutter tensioning and loosening device based on cam-screw mechanism - Google Patents

Abstract

The invention relates to a tool tightening and loosening device based on a cam-screw mechanism. The tool tensioning and loosening device based on the cam-screw mechanism comprises a stand column, wherein a spindle box moving up and down is assembled on the stand column in a sliding mode, and a spindle assembly with a rotation axis extending along the vertical direction is assembled in the spindle box in a rotating mode; the main shaft assembly comprises a main shaft, a screw rod, a guide rod, a pressure spring and a cutter claw, wherein the main shaft is provided with a central through hole, the screw rod is arranged on the upper side of the central through hole in a threaded manner, the guide rod is arranged in the central through hole on the lower side of the screw rod, the cutter claw is connected to the lower end of the guide rod, the pressure spring is sleeved on the guide rod and used for applying upward acting force to the downward guide rod, so that the guide rod is compressed and right when going down, the upward acting force is applied to the guide rod, and the central through hole is provided with a narrow diameter section and is located a wide diameter section. The invention improves the operation quality of the main shaft, prolongs the service life and the reliability of the main shaft, and improves the service life and the reliability of the bearing.

Description

A Tool Tensioning and Loosening Device Based on Cam-Screw Mechanism

technical field

The invention belongs to the technical field of machine tool auxiliary devices, in particular to a tool tightening and loosening device based on a cam-screw mechanism.

Background technique

In the field of mechanical manufacturing, the processing of a part requires the cooperation of multiple processes, and different types and sizes of tools are required to complete, so tool replacement is required.

At present, the tool change principle of the tool tightening and loosening device in the machining center on the market is: the movement of the spindle box along the column (Z direction) is converted into the translation (Z direction) movement of the shift fork through the horizontal axis swing follower moving the cam mechanism, Drive the tool rod (Z direction) to move to realize the tool tightening and loosening. During the tool change (knife punching) process of the current vertical or horizontal machining center, the following phenomena generally exist: (1) The shift fork of the tool change mechanism collides with the knife punching block, which generates an impact load and transmits it to the spindle mandrel and the front and rear of the spindle End support bearing (especially the rear end bearing); (2) There is a space for the shift fork to move on the spindle tool rod, causing the position of the shift fork to move and generate dynamic imbalance; (3) When changing the tool (tightening and loosening the tool) During the process, the spindle bearing always bears the axial force of the broach. The multiple tool change actions, impact load and axial force of the broach in the machining center make the running quality of the main shaft deteriorate, and the bearing fails in advance, which greatly reduces the service life of the bearing and even the main shaft. It is a common difficult problem in the field of machining center manufacturing.

Contents of the invention

In order to solve the above technical problems, the present invention provides a tool tightening and loosening device based on a cam-screw mechanism.

A kind of technical scheme of the tool tightening and unclamping device based on the cam-screw mechanism of the present invention is:

A tool tightening and loosening device based on a cam-screw mechanism, comprising a column on which a spindle box that moves up and down is slidably mounted, and a spindle assembly with a rotation axis extending vertically is rotatably installed in the spindle box;

The main shaft assembly includes a main shaft, a screw mandrel, a guide rod, a compression spring and a knife claw, the main shaft has a central through hole, the screw mandrel is threadedly installed on the upper side of the central through hole, and the guide rod guide is installed on the upper side of the central through hole. In the central through hole on the lower side of the screw rod, the claw is connected to the lower end of the guide rod, and the compression spring is sleeved on the guide rod to apply an upward force to the downward guide rod. The central through hole has a narrow-diameter section and a wide-diameter section. When the pressure spring is in a natural state, the claw arm of the knife claw abuts against the transition position between the narrow-diameter section and the wide-diameter section, so that the knife claw The claw arm is opened when going down, and the claw arm is contracted when the claw is going up;

The tool tightening and loosening device also includes a driving mechanism that drives the screw to rotate; the driving mechanism includes a cam and a cam follower, and one end of the cam follower is provided with a A matching plug, the cam follower is fitted with a guide sleeve, the guide sleeve is rotatably mounted on the headstock, the rotation axis of the guide sleeve extends vertically, and the cam is fixed on the column , the cam is provided with a space groove extending along the arc surface of the cam, one end of the cam follower is slidably installed in the space groove through a ball head, and the ball head slides along the space groove to drive The guide sleeve rotates along the guide sleeve.

As a further improvement to the above technical solution, the column is rotatably equipped with a vertically arranged screw, and the column is fixedly connected with a drive motor that drives the screw to rotate. The headstock includes a box body and a fixing seat. The fixing seat is slidably fitted on the column, and the fixing seat is threadedly engaged with the screw rod.

As a further improvement to the above technical solution, two slide rails arranged in parallel and spaced apart are provided on the column, and slide grooves slidingly matched with the slide rails are provided on the fixing seat.

As a further improvement to the above technical solution, the upper end of the guide rod is provided with a flange extending radially along the guide rod, the central through hole is provided with a step on the lower side of the flange, the pressing The upper end of the spring abuts against the flange, and the lower end abuts against the step.

As a further improvement to the above technical solution, the upper and lower ends of the main shaft are respectively installed in the main shaft box through bearing rotation, the upper end of the main shaft is provided with an upper bearing end cover, and the lower end of the main shaft is provided with a lower bearing end cover.

The invention provides a tool tightening and loosening device based on a cam-screw mechanism. Compared with the prior art, the beneficial effects are:

The tool change principle of the tool tightening and loosening device based on the cam-screw mechanism of the present invention is as follows: the drive motor drives the screw to rotate, the screw drives the headstock to move vertically upward, the cam follower slides along the space groove on the cam, and the cam The follower moves toward the headstock under the action of the guide sleeve until the other end of the cam follower approaches the lead screw and is fixed with the lead screw. The drive motor continues to drive the spindle box upward, the cam follower rotates, and drives the screw to rotate downward. During the downward rotation of the screw, the guide rod is pushed down, and the guide rod compresses the compression spring, and pushes the knife claw. During the downward movement, the contact part between the claw arm of the claw and the transition position between the narrow-diameter section and the wide-diameter section of the central through hole moves downward, and the claw arm opens under the action of its own elastic force, and the knife in the claw The handle is loosened to complete the knife release operation. The drive motor rotates in the opposite direction, driving the screw to rotate upwards, the guide rod goes up under the action of the compression spring, the guide rod drives the claws to go up, and the claw arm of the claw contacts the transition position between the narrow diameter section and the wide diameter section of the central through hole The part moves upwards, and the transition position between the narrow diameter section and the wide diameter section makes the claw arms of the knife claws close, clamps the handle of the knife, and completes the broaching operation. Compared with the tool tensioning and loosening device in the prior art, the tool tensioning and loosening device based on the cam-screw mechanism of the present invention has the following effects:

1. There is no need to set the lever, the axial dimension of the main shaft is reduced, the structure is compact, the hidden danger of the main shaft dynamic unbalance change is eliminated, and the running quality of the main shaft is improved.

2. The axial force during the tool tightening and loosening process is the internal force of the main shaft, which avoids the extra load of the main shaft bearing and improves the service life and reliability of the main shaft.

3. During the tool change process, the force of tightening and loosening the tool handle has nothing to do with the spindle bearing, which eliminates the impact load on the spindle bearing and improves the life and reliability of the bearing.

Description of drawings

Fig. 1 is the structural representation of the tool tightening and unclamping device based on the cam-screw mechanism of the present invention;

Fig. 2 is the partial structure schematic diagram of the tool tightening and unclamping device based on the cam-screw mechanism of the present invention;

Fig. 3 is the structural representation of the cam and the cam follower in the tool tightening and loosening device based on the cam-screw mechanism of the present invention;

4 is a schematic diagram of the internal structure of the headstock of the tool tensioning and loosening device based on the cam-screw mechanism of the present invention;

In the figure: 1. column; 2. slide rail; 3. drive motor; 4. fixed seat; 5. box body; 6. spindle box; 7. chute; 8. cam; Moving part; 11, ball head; 12, guide sleeve; 13, main shaft; 14, nut; 15, nut end cover; 16, sleeve; 17, screw rod; 18, upper bearing end cover; 19, lock nut; 20. Bearing; 21. Lower bearing retaining ring; 22. Lower bearing end cover; 23. Connecting flange; 24. Guide rod; 25. Compression spring; 26. Knife claw. .

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

The specific embodiment of the tool tightening and loosening device based on the cam 8-screw mechanism of the present invention, as shown in Fig. track 2. A screw rod is installed at a position between the two slide rails 2 of the column 1, and the axis of the screw rod extends vertically. The upper end and the lower end of the screw are respectively installed on the column 1 through bearing rotation, the upper end of the screw protrudes to the upper side of the bearing, the drive motor 3 is fixedly installed on the column 1, and the output shaft of the drive motor 3 is fixed to the upper end of the screw through a coupling connect. After the drive motor 3 starts, the drive screw rotates.

In this embodiment, the tool tightening and loosening device based on the cam 8-screw mechanism also includes a spindle box 6, the spindle box 6 includes a fixing seat 4 and a box body 5, and the side of the fixing seat 4 facing the column 1 has two vertical shafts. To the extending chute 7 , the two slide rails 2 are in an I-shaped structure, and the chute 7 is in a shape matched with the slide rail 2 . A threaded hole matching the screw rod is provided on the fixing base 4, and is installed on the screw rod through the threaded hole. When the driving motor 3 drives the screw to rotate, the screw drives the fixed seat 4 to move up and down.

In this embodiment, the main shaft assembly is installed in the box body 5, and the main shaft assembly includes the main shaft 13, the screw rod 17, the guide rod 24, the pressure spring 25 and the knife claw 26, and the box body 5 has installation holes running through the upper and lower ends of the box body 5. , the axes of the mounting holes are arranged vertically. Bearings 20 are respectively installed at the upper and lower ends of the mounting holes, and the main shaft 13 is inserted in the bearings 20 . A sleeve 16 between the bearings at both ends is installed in the mounting hole, and the inner wall of the sleeve 16 is closely attached to the outer wall of the main shaft 13 . The upper and lower ends of the casing 5 are respectively sleeved with an upper bearing end cover 18 and a lower bearing end cover 22, the upper bearing end cover 18 is used to compress the bearing at the upper end, and the lower bearing end cover 22 is used to compress the bearing at the lower end. The lower bearing has a lower bearing retaining ring 21 for compressing the lower end bearing, and the lower bearing end cover 22 is used for compressing the bearing retaining ring. The upper bearing end cover 18 and the lower bearing end cover 22 limit the axial movement of the main shaft 13 . The upper side of the upper bearing end cover 18 has a locking nut 19 for limiting the movement of the upper bearing end cover 18 . A connecting flange 23 is connected to the lower side of the lower bearing end cover 22 .

In this embodiment, the main shaft 13 has a central through hole, a nut 14 is installed on the upper side of the central through hole, and a nut end cover 15 is provided on the upper side of the central through hole, and the nut end cover 15 is used to limit the nut 14 along the axial direction of the central through hole. Movement, screw mandrel 17 threads are installed in the nut 14. The guide rod 24 is guided and installed in the central through hole on the lower side of the screw mandrel 17, the claw 26 is connected to the lower end of the guide rod 24, and the clip spring 25 is sleeved on the guide rod 24 for An upward force is applied to the downward guide rod 24, so that the guide rod 24 is compressed when it descends and an upward force is applied to the guide rod 24. The central through hole has a narrow diameter section and a wide diameter section, When the compression spring 25 is in the natural state, the claw arm of the knife claw 26 abuts against the transition position between the narrow diameter section and the wide diameter section, so that the claw arm opens when the knife claw 26 descends, and the The claw arm shrinks when the knife claw 26 goes up and down. The upper end of the guide rod 24 is provided with a flange extending radially along the guide rod 24, and a step positioned at the lower side of the flange is provided in the central through hole, and the upper end of the clip spring 25 is in contact with the flange. Abutting, the lower end abuts against the step. The upper end of the screw rod 17 is provided with a socket, and the outer wall of the main shaft 13 has a through hole communicating with the socket.

In this embodiment, the tool tightening and loosening device based on the cam 8-screw mechanism also includes a driving mechanism that drives the screw mandrel 17 to rotate. The driving mechanism includes a cam 8 and a cam follower 10, and the cam follower 10 One end is provided with a plug that fits with the screw rod 17 , and the plug is inserted into the socket on the screw rod 17 through the through hole on the main shaft 13 to realize the fixed connection between the cam follower 10 and the screw rod 17 . A guide sleeve 12 is set on the cam follower 10, and the guide sleeve 12 is rotatably mounted on the fixed seat 4. The rotation axis of the guide sleeve 12 extends vertically, and the cam 8 is fixed on the column 1. Above, the cam 8 is provided with a space groove extending along the arc surface of the cam 8, and one end of the cam follower 10 is slidably installed in the space groove through a ball head 11, and the ball head 11 is installed along the arc surface of the cam. When the space groove slides, the guide sleeve 12 is driven to rotate along the guide sleeve 12 .

The tool change principle of the tool tensioning and loosening device based on the cam 8-screw mechanism of the present invention is as follows: the driving motor 3 drives the screw to rotate, the screw drives the spindle box 6 to move vertically upward, and the cam follower 10 moves along the cam 8. The space groove slides, and the cam follower 10 moves toward the headstock 6 under the action of the guide sleeve 12 until the other end of the cam follower 10 approaches the screw mandrel 17 and is fixed with the screw mandrel 17 . Drive motor 3 continues to drive headstock 6 to go up, and cam follower 10 rotates, and drives screw mandrel 17 to rotate downwards, and screw mandrel 17 pushes guide rod 24 to go down during the downward rotation process, and guide rod 24 compresses clip spring 25, and Push the claw 26 to think about it. During the downward process of the claw 26, the contact part between the claw arm of the claw 26 and the transition position between the narrow diameter section and the wide diameter section of the central through hole moves downward, and the claw 26 is on the claw arm. Open under the action of elastic force, the handle of a knife in the claw 26 is loosened, and the operation of loosening the knife is completed. Drive motor 3 counter-rotates, drives screw mandrel 17 to rotate upwards, and guide rod 24 goes up under stage clip 25 effects, and guide rod 24 drives knife claw 26 to go up, and the claw arm of knife claw 26 and the narrow diameter section and the width of central through hole The contact part of the transition position of the diameter section moves upwards, and the transition position of the narrow diameter section and the wide diameter section makes the claw arm of the knife claw 26 close up, the handle of a knife is clamped, and the broaching operation is completed. Compared with the tool tensioning and loosening device in the prior art, the tool tensioning and loosening device based on the cam 8-screw mechanism of the present invention has the following effects: 1. It does not need to set a lever, reducing the number of shafts of the main shaft 13 The dimension is small, the structure is compact, the hidden danger of the dynamic imbalance of the main shaft 13 is eliminated, and the running quality of the main shaft 13 is improved.

2. During the tightening and loosening process of the tool, the axial force is the internal force of the main shaft 13, which avoids the extra load of the bearing of the main shaft 13 and improves the service life and reliability of the main shaft 13.

3. During the tool change process, the force of tightening and loosening the tool handle has nothing to do with the bearing of the main shaft 13, which eliminates the impact load on the bearing of the main shaft 13 and improves the life and reliability of the bearing.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (5)

1. A cutter tensioning and loosening device based on a cam-screw mechanism is characterized by comprising a stand column, wherein a spindle box which moves up and down is assembled on the stand column in a sliding mode, and a spindle assembly with a rotating axis extending vertically is assembled in the spindle box in a rotating mode;

the main shaft assembly comprises a main shaft, a screw rod, a guide rod, a pressure spring and a cutter claw, wherein the main shaft is provided with a central through hole, the screw rod is installed on the upper side of the central through hole in a threaded manner, the guide rod is installed in the central through hole on the lower side of the screw rod in a guiding manner, the cutter claw is connected to the lower end of the guide rod, the pressure spring is sleeved on the guide rod and is used for applying upward acting force to a descending guide rod, the central through hole is provided with a narrow diameter section and a wide diameter section, and a claw arm of the cutter claw is abutted to the transition position of the narrow diameter section and the wide diameter section when the pressure spring is in a natural state, so that the claw arm is expanded when the cutter claw descends and the claw is contracted when the cutter claw ascends;

the tool tensioning and loosening device also comprises a driving mechanism for driving the screw rod to rotate; the driving mechanism comprises a cam and a cam follower, one end of the cam follower is provided with a plug matched with the screw rod in a plug-in mounting mode, the cam follower is sleeved with a guide sleeve, the guide sleeve is rotatably installed on the spindle box, the rotation axis of the guide sleeve extends vertically, the cam is fixed on the stand column, the cam is provided with a space groove extending along the arc surface of the cam, one end of the cam follower is slidably installed in the space groove through a ball head, and the ball head drives the guide sleeve to rotate along the guide sleeve when sliding in the space groove.

2. The cam-screw mechanism-based tool tensioning and releasing device according to claim 1, wherein the upright is rotatably assembled with a vertically arranged screw, the upright is fixedly connected with a driving motor for driving the screw to rotate, the spindle box comprises a box body and a fixed seat, the fixed seat is slidably assembled on the upright, and the fixed seat is in threaded fit with the screw.

3. The cutter tensioning and releasing device based on the cam-screw mechanism as claimed in claim 2, wherein two parallel slide rails are arranged on the upright post at intervals, and the fixing seat is provided with a sliding groove in sliding fit with the slide rails.

4. The cutter tightening and loosening device based on the cam-and-screw mechanism as claimed in any one of claims 1 to 3, wherein the guide rod is provided at an upper end thereof with a flange extending in a radial direction of the guide rod, a step is provided in the central through hole at a lower side of the flange, and the compression spring is abutted at an upper end thereof with the flange and at a lower end thereof with the step.

5. The tool tightening and loosening device based on the cam-screw mechanism as claimed in any one of claims 1 to 3, wherein the upper and lower ends of the main shaft are rotatably mounted in the main spindle box through bearings, respectively, the upper end of the main shaft is provided with an upper bearing cap, and the lower end of the main shaft is provided with a lower bearing cap.

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