CN112775788A

CN112775788A - Machine tool for repairing surface of die

Info

Publication number: CN112775788A
Application number: CN202110004821.2A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-05-11

Abstract

The invention discloses a machine tool for repairing the surface of a die, which comprises a positioning frame mechanism and a trimming head mechanism, wherein the positioning frame mechanism has six spatial degrees of freedom, and each movable joint is provided with a graduated scale, the trimming head mechanism adopts five-gear variable transmission and is tightly arranged at the tail end of the positioning frame mechanism, is used for repairing the surface of the die, the trimming head mechanism adopts a gear with smaller transmission during idle stroke, can shorten the moving time of the polishing head, the gear with larger transmission is adopted when the surface of the die is trimmed, the processing quality of the surface of the die can be improved, the gear is changed by changing the position of the shift lever, the inside of the trimming head mechanism adopts a transmission structure of a worm gear, so that the transmission is stable, the self-locking function is realized, the reaction force of the mold surface to the polishing head cannot react on the hand wheel through the transmission mechanism, and the stable trimming processing can be carried out on the mold surface through rotating the hand wheel.

Description

Machine tool for repairing surface of die

Technical Field

The invention relates to the field of machining, in particular to a machine tool for repairing the surface of a die.

Background

Molds play an extremely important role in modern industry, and the quality of a mold directly determines the quality of a product. The mold industry in China is rapidly developed in recent years and ascends three mold production countries in the world, but the mold industry in China has a larger difference compared with the production level of foreign advanced molds, and the difference is mainly expressed in the aspects of long manufacturing period, low manufacturing precision, short service life of the molds and the like, wherein the problem of short service life of the molds is particularly prominent, and the resource waste and the production cost are directly increased, so that the failed molds are repaired and reused, the service time of the molds is prolonged, unnecessary loss in production is recovered, the development of industry and national economy is greatly promoted, and the mold industry has remarkable economic benefit and social significance.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a machine tool for repairing the surface of a mold, which is novel in structure and convenient to use.

The technical scheme adopted by the invention is as follows: the utility model provides a repair lathe on mould surface, includes locating rack mechanism and repaiies first mechanism, its characterized in that: the positioning frame mechanism has six spatial degrees of freedom, each movable joint is provided with a graduated scale, and the trimming head mechanism adopts five-gear variable transmission and is fixedly arranged at the tail end of the positioning frame mechanism for repairing the surface of the mold.

Preferably, the positioning frame mechanism comprises a base, a positioning sleeve, a sliding sleeve, an upright post, a second screw, a thimble sleeve, a fourth screw, a cross arm, a third screw, a first screw, a sixth screw, a swinging frame, a swinging rod, a fifth screw, a nut and a swinging head, wherein the base is fixedly arranged on the ground, the upright post is fixedly connected with the base, the sliding sleeve can move and rotate on the upright post through the pointer sleeve and is locked by the third screw, the positioning sleeve and the first screw are convenient for realizing the height positioning of the sliding sleeve, the cross arm and the sliding sleeve form a rotating pair and are locked by the second screw, the transverse swinging rod can form a rotating pair with the cross arm and is locked by the fourth screw, the swinging frame and the swinging rod form a rotating pair and is locked by the fifth screw, and the swinging head and the swinging frame form a rotating pair and is locked by the sixth screw.

Preferably, the trimming head mechanism is tightly connected with the tail end of the positioning frame mechanism and comprises a shell, a worm wheel, a threaded shaft, a moving shaft, a motor, a clamping piece, a polishing head, a fourth bevel gear, a worm, a third bevel gear, a second bevel gear tower, a first gear tower, a second bevel gear, a hand wheel, a rear cover, a top ball, a first bevel gear, a driven pinion, a second retaining rod, a transmission pinion, a driving gear, a driving pinion, a retaining sheet, a first retaining rod, a pull rod, a spring, a deflector rod and a sliding frame, wherein the shell is a supporting body, the motor drives the polishing head to rotate through the clamping piece to trim the surface of the mold, and the polishing head can be fed and retracted by rotating the hand wheel; the five-gear variable-speed transmission mechanism composed of the worm wheel, the threaded shaft, the moving shaft, the fourth bevel gear, the worm, the third bevel gear, the second gear tower, the first gear tower, the second bevel gear, the hand wheel, the rear cover, the first bevel gear, the driven pinion, the second retaining rod, the transmission pinion, the driving gear, the driving pinion, the retaining sheet, the first retaining rod, the pull rod, the spring, the shift rod and the sliding frame can adjust the transmission ratio according to the feeding requirement, the idle stroke can be fed by adopting a faster gear, the moving time of the polishing head is shortened, the surface of the mold can be fed by adopting a slower gear when being trimmed, and the surface processing quality of the mold is improved.

Preferably, the base is fixedly installed on the ground through foundation bolts to provide stable support for the positioning frame mechanism, the lower end of the upright post is fixedly installed on the upper side of the base through screws and enables the upright post to be kept in a vertical state, the front side surface of the upright post is provided with first scales, the left side of the upright post is vertically provided with a guide groove, the needle sleeve is of an open cylindrical structure, the upper end of the needle sleeve is provided with a third pointer, the inner side of the needle sleeve is longitudinally provided with a guide strip, the needle sleeve and the upright post are coaxially installed, the guide strip is installed in the guide groove, so that the needle sleeve and the upright post form a moving pair, the upper end of the sliding sleeve is provided with third scales, the left side of the sliding sleeve is provided with a fan-shaped structure, the fan-shaped structure is provided with second scales and an arc-shaped hole, a longitudinal opening formed in the right side of the sliding sleeve can be installed on the outer side of the needle sleeve and form a rotating pair, thereby realize the rotation locking and the high location of slip commentaries on classics cover, the position sleeve is opening ring shape structure, and the position sleeve can slide on the stand with stand coaxial arrangement, is equipped with the recess on the plane of position sleeve upper end, is convenient for read first scale, screws up first screw and can realize the fixed of position sleeve on the stand.

The auxiliary connecting part of the sliding sleeve is heavy and is not convenient for direct accurate height positioning, so when the height of the sliding sleeve needs to be adjusted, the first screw is firstly unscrewed, the positioning sleeve is moved to enable the upper end plane of the positioning sleeve to move to a target scale, the first screw is locked to enable the positioning sleeve to be fastened on the upright post, then the two third screws are unscrewed, the sliding sleeve is moved downwards to enable the lower end surface of the sliding sleeve to be tightly attached to the upper end plane of the positioning sleeve, and then the two third screws are locked, so that the accurate height adjustment of the sliding sleeve is completed.

Preferably, the left end of the cross arm is of an open structure and is provided with a second pointer, the right end of the cross arm is provided with a cross arm disc and a fourth pointer, the left side of the cross arm and the sliding sleeve form a rotating pair, a second screw can penetrate through an arc-shaped hole in the left side of the sliding sleeve to enable the left end of the cross arm to clamp a sector structure in the left side of the sliding sleeve, so that the rotation locking of the cross arm is realized, the rotating angle of the cross arm relative to the sliding sleeve can be indicated on a second scale by the second pointer, three arc-shaped holes are uniformly distributed in the circumferential direction on the cross arm disc, the upper end of the yaw rod is provided with an upper scale, the upper scale is provided with a fourth scale and three threaded holes uniformly distributed in the circumferential direction, the upper scale can form a rotating pair with the cross arm disc and can be locked by three fourth screws, the rotating angle of the yaw rod relative to the cross arm can be indicated on, the left side of the swing frame is provided with a swing frame disc and a fifth pointer, the upper side of the swing frame disc is provided with a sixth pointer, three arc-shaped holes are uniformly distributed on the swing frame disc in the circumferential direction, the swing frame disc and the lower dial form a revolute pair and can be locked by three fifth screws, the rotation angle of the swing frame relative to the transverse swing rod can be indicated on a fifth scale by the fifth pointer, the upper end of the swing head is of a semi-circular plate structure, the semi-circular plate structure is provided with sixth scales and the arc-shaped holes, the semi-circular plate structure and the right side of the swing frame form a revolute pair, the sixth screw penetrates through the arc-shaped hole on the semi-circular plate structure and forms a thread pair with the swing frame, the rotation of the swing head relative to the swing frame can be locked by screwing the sixth screw, the rotation angle of the swing head relative to the swing frame can be indicated on the sixth scales by the sixth pointer, the lower end of the swing head is provided with a thread pair, for locking the expansion device.

Preferably, the right end of the shell is provided with an internal spline, the side surface of the shell is provided with a transverse groove and a gear scale, the upper side of the transverse groove is provided with five top balls, each top ball corresponds to one gear and is used for realizing accurate positioning of the sliding frame, two side walls of the inner part of the transverse groove are horizontally provided with four guide rails, the rear cover is fixedly arranged at the left end of the shell through screws, the rear cover is provided with a threaded hole, the threaded hole and the threaded rod form a threaded pair and form a double-nut anti-loose structure through nut locking, so that the trimming head mechanism is fixedly connected with the tail end of the positioning frame mechanism, the hand wheel is arranged at the upper side of the shell and forms a rotating pair, the first bevel gear is coaxially and fixedly connected with the lower end of the hand wheel, the right end of the threaded shaft is provided with a threaded structure, the threaded shaft is, the worm and the worm wheel are meshed to form a worm and gear transmission structure, the fourth bevel gear is coaxially and tightly mounted at the left end of the worm, the polishing head is tightly connected with an output shaft of the motor through a clamping piece, the motor is fixedly mounted at the right end of the moving shaft, an external spline arranged at the left end of the moving shaft is matched and mounted with an internal spline at the right end of the shell, so that the moving shaft and the shell form a moving pair, a threaded hole arranged inside the moving shaft is matched and mounted with the right end of the threaded shaft to form a thread transmission structure, and the threaded shaft can drive the moving shaft to move rightwards and leftwards after rotating, so that feeding and.

Preferably, a five-layer gear structure is arranged on the first gear tower, the reference circle diameters of the five-layer gear structure are in an equal-difference number sequence and form five gears, the first gear tower is obliquely arranged in the shell and forms a rotating pair, the large end of the first gear tower faces to the right from the left, the second bevel gear is coaxially and fixedly connected with the left end of the first gear tower, the second bevel gear and the first bevel gear form gear meshing transmission, the parameters of the five-layer gear structure arranged on the second gear tower are the same as those of the five-layer gear structure on the first gear tower, the second gear tower is obliquely arranged in the shell and forms a rotating pair, the large end of the second gear tower faces to the left from the right, the second gear tower is positioned above the first gear tower, the central axes of the first gear tower and the second gear tower are parallel to each other, the third bevel gear tower is coaxially and fixedly connected with.

Preferably, the sliding frame is arranged inside the shell, the right end of the sliding frame is positioned in the transverse slot, the two sliding block structures arranged at the left end of the sliding frame and the two sliding block structures arranged at the right end of the sliding frame are respectively matched and arranged with four guide rails on two side walls inside the shell, so that the sliding frame and the shell form a moving pair, the sliding frame is provided with a round hole and a long slot hole close to the middle position, the right end of the sliding frame is provided with a gear pointer and a positioning hole, the second retaining rod is arranged in the round hole to form a rotating pair, two transmission auxiliary gears are respectively and coaxially and tightly arranged at two ends of the second retaining rod, the first retaining rod can slide in the long slot hole, the driving gear is positioned at the lower side between the first retaining rod and the second retaining rod, the two driving auxiliary gears are respectively and coaxially and tightly arranged at two ends of the driving gear, two ends, the driving pinion is always meshed with the driving pinion, an annular groove is formed in the middle of the driven gear to prevent interference with the driving gear when the feeding gear is changed, the driven gear is located on the upper side between the first retaining rod and the second retaining rod, the two driven pinions are respectively and coaxially and fixedly mounted at two ends of the driven gear, two ends of the driven gear are rotatably connected with the first retaining rod through the two retaining pieces, and two ends of the driven gear are further rotatably connected with the second retaining rod through the two retaining pieces to enable the driven pinions to be always meshed with the driving pinion.

Preferably, the left end of the pull rod and the first retaining rod form a rotating pair, a spring is arranged between the left end of the pull rod and the right side of the sliding frame, the right end of the pull rod and the upper end of the deflector rod form a rotating pair, and the lower end of the deflector rod is provided with a cross rod structure convenient to hold.

In the initial state, the deflector rod is in a vertical state, the pull rod moves leftwards under the action of the elastic force of the spring, so that the first retaining rod slides leftwards in the long slot, the driving gear moves downwards and is meshed with one gear of the first gear tower, and the driven gear moves upwards and is meshed with a corresponding gear on the second gear tower under the action of the thrust of the eight retaining pieces.

The motor can drive the polishing head to rotate, so that the surface of the die can be trimmed.

The chucking piece can be with polishing head and motor output shaft fastening connection, can take off the polishing head and change other kinds of polishing head according to mould material and surface characteristic after unscrewing the chucking piece.

When the surface of the die is repaired, firstly, the height of a sliding sleeve in a positioning frame mechanism and the rotation amount of each joint need to be adjusted, so that a polishing head is aligned to the position of the surface of the die to be corrected, and then a hand wheel is rotated to feed the polishing head forward, so that the repair of the surface of the die is gradually completed.

After the hand wheel is rotated clockwise, the first bevel gear drives the first gear tower to rotate clockwise through the second bevel gear, the first gear tower drives the driving gear to rotate anticlockwise through gear meshing, so that the driving pinion rotating anticlockwise drives the driven pinion to rotate anticlockwise through the gear meshing relation between the driving pinion and the driven pinion, the driven pinion drives the second gear tower and the third bevel gear to rotate clockwise through the gear meshing relation between the driven gear and the second gear tower, the third bevel gear drives the fourth bevel gear and the worm to rotate clockwise, the worm drives the worm gear and the threaded shaft to rotate clockwise, and under the transmission action of the threaded pair, the moving shaft moves rightwards, so that the polishing head moves rightwards and feeds, and the surface of the die is trimmed; the backward movement of the polishing head can be realized by rotating the hand wheel anticlockwise.

When the transmission ratio needs to be increased to slow down the feeding speed, the shifting lever is pulled upwards to be in a horizontal state, in the process, the pull rod pulls the first retaining rod to move rightwards, the driving gear moves upwards and is disengaged from a gear on the first gear tower under the action of the pulling force of the eight retaining pieces, the driven gear moves downwards and is disengaged from a gear on the second gear tower, then the shifting lever moves rightwards to be in a proper gear position, the top ball is clamped into the positioning hole to accurately position the sliding frame, the shifting lever is pulled downwards to be in a vertical state, the driving gear is engaged with a smaller gear on the first gear tower at the moment, and the driven gear is engaged with a larger gear on the second gear tower, so that the transmission ratio between the first gear tower and the second gear tower is increased, and the feeding speed of the polishing head is slowed down; conversely, moving the lever to the left, the transmission ratio may be decreased to increase the feed rate of the sanding head.

The feed gear of the trimmer head mechanism can be indicated on the gear scale by the gear pointer.

The invention has the beneficial effects that:

firstly, the positioning frame mechanism has six spatial degrees of freedom and great flexibility, and the trimming head mechanism can trim the surface of any position and any angle on the die;

each movable joint of the positioning frame mechanism is provided with scale display, so that the head trimming mechanism can be accurately positioned in space;

each movable joint of the positioning frame mechanism is convenient to adjust, and electrified equipment is not adopted, so that the positioning frame mechanism is reliable in connection and positioning, low in failure rate, effective in reducing the manufacturing cost and beneficial to large-scale popularization and application;

the trimming head mechanism has a five-gear speed regulation function, adopts a small transmission ratio during idle stroke, can shorten the moving time of a polishing head, adopts a large transmission ratio during trimming the surface of the die, and can improve the processing quality of the surface of the die;

the feeding speed regulation of the trimming head mechanism is realized by changing the gear of the deflector rod to change the transmission ratio, when the deflector rod is at the left end gear, the feeding speed is fastest, when the deflector rod is at the right end gear, the feeding speed is slowest, and the feeding gear can be visually displayed on the gear scale by a gear pointer;

when the shift lever is adopted to adjust the gears, the driving gear is disengaged from the first gear tower, the driven gear is disengaged from the second gear tower, and then the positions of the driving gear and the driven gear are moved to carry out gear change, so that the transmission structure is very compact, and the problems of complex structure and large size of a multi-gear transmission device are solved by an innovative design;

and the inside of the trimming head mechanism adopts a transmission structure of a worm gear and a worm, so that the transmission is stable, the self-locking function is realized, the reaction force of the surface of the mold on the polishing head cannot react on the hand wheel through the transmission mechanism, and the surface of the mold can be trimmed and processed stably by rotating the hand wheel.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic view of the overall structure of the present invention.

Fig. 3 is a schematic overall structure diagram of the positioning frame mechanism.

Fig. 4 is an exploded view of the positioner mechanism.

Fig. 5 is a partial schematic view of the carriage mechanism.

Fig. 6 is a partial schematic view of the carriage mechanism.

Fig. 7 is a schematic view of the overall structure of the dressing head mechanism.

Fig. 8 is a schematic longitudinal sectional view of the trimming head mechanism at the left end gear position.

Fig. 9 is a schematic longitudinal sectional view of the dressing head mechanism in the right gear position.

Fig. 10 is a partial schematic view of the shifting mechanism.

Fig. 11 is a schematic diagram of an oblique cross-sectional structure of the trimming head mechanism.

Fig. 12 is a schematic diagram of an oblique cross-sectional structure of the trimming head mechanism.

Fig. 13 is a partial cross-sectional schematic view of a trimming head mechanism.

Fig. 14 is an exploded view of the dressing head mechanism.

Fig. 15 is a schematic view of the carriage.

Reference numerals: 1 positioning frame mechanism, 101 base, 102 positioning sleeve, 103 sliding sleeve, 103.1 second scale, 103.2 third scale, 104 upright post, 104.1 first scale, 104.2 guide groove, 105 second screw, 106 needle sleeve, 106.1 third pointer, 107 fourth screw, 108 cross arm, 108.1 cross arm disc, 108.2 fourth pointer, 108.3 second pointer, 109 third screw, 110 first screw, 111 sixth screw, 112 swinging frame, 112.1 sixth pointer, 112.2 swinging frame disc, 112.3 fifth pointer, 113 swinging rod, 113.1 upper scale, 113.2 lower scale, 114 fifth screw, 115 nut, 116 swinging head, 116.1 sixth scale, 116.2 threaded rod;

2 trimming head mechanism, 201 shell, 201.1 internal spline, 201.2 transverse groove, 201.3 gear scale, 202 worm wheel, 203 threaded shaft, 204 moving shaft, 205 motor, 205.1 clamping piece, 205.2 grinding head, 206 fourth bevel gear, 207 worm, 208 third bevel gear, 209 second gear tower, 210 first gear tower, 211 second bevel gear, 212 hand wheel, 213 back cover, 213.1 threaded hole, 214 top ball, 215 first bevel gear, 216 driven gear, 216.1 driven secondary gear, 217 second retaining rod, 217.1 transmission secondary gear, 218 driving gear, 218.1 driving secondary gear, 219 retaining piece, 220 first retaining rod, 221 pull rod, 222 spring, 223, 224 sliding frame, 224.1 round hole, 224.2 long groove hole, 224.3 gear pointer and 224.4 shift rod positioning hole.

Detailed Description

The invention will be further described with reference to the drawings and specific embodiments, which are illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 and 2, a machine tool for repairing a mold surface includes a positioning frame mechanism 1 and a trimming head mechanism 2, and is characterized in that: the positioning frame mechanism 1 has six spatial degrees of freedom, each movable joint is provided with a graduated scale, and the trimming head mechanism 2 adopts five-gear variable transmission and is fixedly arranged at the tail end of the positioning frame mechanism 1 and used for repairing the surface of a mold.

As shown in fig. 3 to 6, the positioning frame mechanism 1 includes a base 101, a positioning sleeve 102, a sliding sleeve 103, a column 104, a second screw 105, a pointer sleeve 106, a fourth screw 107, a cross arm 108, a third screw 109, a first screw 110, a sixth screw 111, a swing frame 112, a yaw rod 113, a fifth screw 114, a nut 115, and a swing head 116, wherein the base 101 is fixedly mounted on the ground, the column 104 is fixedly connected with the base 101, the sliding sleeve 103 can move and rotate on the column 104 through the pointer sleeve 106 and is locked by the third screw 109, the positioning sleeve 102 and the first screw 110 facilitate height positioning of the sliding sleeve 103, the cross arm 108 and the sliding sleeve 103 form a rotation pair and is locked by the second screw 105, the yaw rod 113 and the cross arm 108 form a rotation pair and is locked by the fourth screw 107, the swing frame 112 and the yaw rod 113 form a rotation pair and is locked by the fifth screw 114, the swing head 116 may form a rotation pair with the swing frame 112 and be locked by the sixth screw 111.

As shown in fig. 7 to 15, the trimming head mechanism 2 is firmly connected to the end of the positioning frame mechanism 1, and includes a housing 201, a worm gear 202, a threaded shaft 203, a moving shaft 204, a motor 205, a clamping member 205.1, a polishing head 205.2, a fourth bevel gear 206, a worm 207, a third bevel gear 208, a second gear tower 209, a first gear tower 210, a second bevel gear 211, a hand wheel 212, a rear cover 213, a top ball 214, a first bevel gear 215, a driven gear 216, a driven pinion 216.1, a second holding rod 217, a transmission pinion 217.1, a driving gear 218, a driving pinion 218.1, a holding piece 219, a first holding rod 220, a pulling rod 221, a spring 222, a shifting rod 223, and a sliding frame 224, wherein the housing 201 is a supporting body, the motor 205 drives the polishing head 205.2 to rotate through the clamping member 205.1, so as to trim the surface of the mold, and the polishing head 205.2 can be fed and retracted by rotating the hand wheel 212; the five-gear variable transmission mechanism consisting of the worm wheel 202, the threaded shaft 203, the moving shaft 204, the fourth bevel gear 206, the worm 207, the third bevel gear 208, the second gear tower 209, the first gear tower 210, the second bevel gear 211, the hand wheel 212, the rear cover 213, the first bevel gear 215, the driven gear 216, the driven pinion 216.1, the second retaining rod 217, the transmission pinion 217.1, the driving gear 218, the driving pinion 218.1, the retaining piece 219, the first retaining rod 220, the pull rod 221, the spring 222, the shift lever 223 and the sliding frame 224 can adjust the transmission ratio according to the feeding requirement, can adopt a faster gear to feed during idle stroke, shortens the grinding head moving time, can adopt a slower gear to feed during the trimming of the surface of the mold, and improves the processing quality of the surface of the mold.

As shown in fig. 3 to 6, the base 101 is fixedly mounted on the ground through anchor bolts to provide stable support for the spacer mechanism 1, the lower end of the upright 104 is fixedly mounted on the upper side of the base 101 through screws to keep the upright 104 in a vertical state, the front side of the upright 104 is provided with a first scale 104.1, the left side of the upright 104 is vertically provided with a guide slot 104.2, the pointer sleeve 106 is an open cylindrical structure, the upper end of the pointer sleeve 106 is provided with a third pointer 106.1, the inner side of the pointer sleeve is longitudinally provided with a guide bar, the pointer sleeve 106 is coaxially mounted with the upright 104, the guide bar is mounted in the guide slot 104.2, so that the pointer sleeve 106 and the upright 104 form a moving pair, the upper end of the sliding sleeve 103 is provided with a third scale 103.2, the left side of the sliding sleeve is provided with a fan-shaped structure, the fan-shaped structure is provided with a second scale 103.1 and an arc-shaped hole, the longitudinal open circular hole formed on the right side of the sliding sleeve 103 can be mounted on the outer side of the pointer sleeve 106 and form, the two third screws 109 can enable the sliding sleeve 103 to clamp the thimble sleeve 106 and be fixed on the upright post 104, so that rotation locking and height positioning of the sliding sleeve 103 are realized, the positioning sleeve 102 is of an open circular ring structure, the positioning sleeve 102 and the upright post 104 are coaxially mounted and can slide on the upright post 104, a groove is formed in the plane of the upper end of the positioning sleeve 102, reading of the first scale 104.1 is facilitated, and the positioning sleeve 102 can be fixed on the upright post 104 by tightening the first screw 110.

When the height of the sliding sleeve 103 needs to be adjusted, the first screw 110 is firstly unscrewed, the positioning sleeve 102 is moved to move the upper end plane to the target scale, the first screw 110 is locked to fasten the positioning sleeve 102 on the upright post 104, then the two third screws 109 are unscrewed, the sliding sleeve 103 is moved downwards to enable the lower end plane to be tightly attached to the upper end plane of the positioning sleeve 102, and then the two third screws 109 are locked to finish the accurate height adjustment of the sliding sleeve 103.

The left end of the cross arm 108 is of an open structure and is provided with a second pointer 108.3, the right end of the cross arm 108 is provided with a cross arm disc 108.1 and a fourth pointer 108.2, the left side of the cross arm 108 and the sliding sleeve 103 form a rotation pair, the second screw 105 can penetrate through an arc hole on the left side of the sliding sleeve 103 to enable the left end of the cross arm 108 to clamp a sector structure on the left side of the sliding sleeve 103, so that the rotation locking of the cross arm 108 is realized, the rotation angle of the cross arm 108 relative to the sliding sleeve 103 can be indicated on a second scale 103.1 through the second pointer 108.3, three arc holes are uniformly distributed on the cross arm disc 108.1 in the circumferential direction, the upper end of the yaw rod 113 is provided with an upper scale 113.1, the upper scale 113.1 is provided with a fourth scale and three threaded holes uniformly distributed in the circumferential direction, the upper scale 113.1 can form a rotation pair with the cross arm disc 108.1 and can be locked through three fourth screws 107, the rotation angle of, the lower end of the horizontal swing rod 113 is provided with a lower dial 113.2, the lower dial 113.2 is provided with a fifth scale and three threaded holes which are uniformly distributed in the circumferential direction, the left side of the swing frame 112 is provided with a swing frame disc 112.2 and a fifth pointer 112.3, the upper side of the swing frame disc is provided with a sixth pointer 112.1, the upper side of the swing frame disc 112.2 is uniformly distributed with three arc-shaped holes in the circumferential direction, the swing frame disc 112.2 and the lower dial 113.2 can form a revolute pair and can be locked by three fifth screws 114, the rotating angle of the swing frame 112 relative to the horizontal swing rod 113 can be indicated on the fifth scale by the fifth pointer 112.3, the upper end of the swing head 116 is of a semicircular plate structure, the semicircular plate structure is provided with the sixth scale 116.1 and the arc-shaped holes, the semicircular plate structure and the right side of the swing frame 112 form a revolute pair, the sixth screw 111 passes through the arc-shaped holes on the semicircular plate structure and then forms a threaded pair with the swing frame 112, the sixth screw, the rotation angle of the swing head 116 relative to the swing frame 112 can be indicated on the sixth scale 116.1 by the sixth pointer 112.1, the lower end of the swing head 116 is provided with a threaded rod 116.2 for connecting the expansion device, and the nut 115 and the threaded rod 116.2 form a thread pair for locking the expansion device.

As shown in fig. 7 to 15, the right end of the housing 201 is provided with an internal spline 201.1, the side surface is provided with a transverse slot 201.2 and a gear scale 201.3, the upper side of the transverse slot 201.2 is provided with five top balls 214, each top ball 214 corresponds to a gear for accurately positioning the sliding frame 224, two side walls of the interior of the housing are horizontally provided with four guide rails, the rear cover 213 is fixedly mounted at the left end of the housing 201 through screws, the rear cover 213 is provided with a threaded hole 213.1, the threaded hole 213.1 and the threaded rod 116.2 form a threaded pair and are locked through a nut 115 to form a double-nut anti-loose structure, so as to realize the fastening connection of the trimming head mechanism 2 and the tail end of the positioning frame mechanism 1, the hand wheel 212 is mounted at the upper side of the housing 201 and form a rotating pair, the first bevel gear 215 is coaxially and fixedly connected with the lower end of the hand wheel 212, the right end of the, the worm wheel 202 is coaxially and tightly connected with the left end of the threaded shaft 203, the worm 207 is horizontally arranged in the shell 201 to form a rotation pair, the worm 207 is meshed with the worm wheel 202 to form a worm wheel and worm transmission structure, the fourth bevel gear 206 is coaxially and tightly arranged at the left end of the worm 207, the polishing head 205.2 is tightly connected with an output shaft of the motor 205 through a clamping piece 205.1, the motor 205 is fixedly arranged at the right end of the moving shaft 204, an external spline arranged at the left end of the moving shaft 204 is matched and arranged with an internal spline 201.1 at the right end of the shell 201, so that the moving shaft 204 and the shell 201 form a movement pair, a threaded hole arranged in the moving shaft 204 is matched and arranged with the right end of the threaded shaft 203 to form a thread transmission structure, and the threaded shaft 203 can drive the moving shaft 204 to move right.

The first gear tower 210 is provided with five layers of gear structures, the reference circle diameters of the five layers of gear structures are in an arithmetic progression and form five gears, the first gear tower 210 is obliquely arranged in the shell 201 and forms a revolute pair, and the big end is towards the left and the small end is towards the right, the second bevel gear 211 is coaxially and tightly connected with the left end of the first gear tower 210, the second bevel gear 211 and the first bevel gear 215 form gear mesh transmission, the parameters of a five-layer gear structure arranged on the second gear tower 209 are the same as those of the five-layer gear structure on the first gear tower 210, the second gear tower 209 is obliquely arranged inside the shell 201 and forms a revolute pair, and the large end to the right and the small end to the left, the second gear tower 209 is located above the first gear tower 210, the central axes of the third bevel gear 208 and the fourth bevel gear 206 are parallel to each other, the third bevel gear 208 is coaxially and fixedly connected with the right end of the second gear tower 209, and the third bevel gear 208 and the fourth bevel gear 206 form gear meshing transmission.

The sliding frame 224 is installed inside the casing 201, the right end of the sliding frame 224 is positioned in the transverse slot 201.2, the two sliding block structures arranged at the left end of the sliding frame 224 and the two sliding block structures arranged at the right end of the sliding frame 224 are respectively installed in a matching way with four guide rails on two side walls inside the casing 201, so that the sliding frame 224 and the casing 201 form a moving pair, the sliding frame 224 is provided with a round hole 224.1 and a long slot hole 224.2 near the middle position, the right end of the sliding frame 224 is provided with a gear position pointer 224.3 and a positioning hole 224.4, the second retaining rod 217 is installed in the round hole 224.1 to form a rotating pair, two transmission auxiliary gears 217.1 are respectively and coaxially and tightly installed at two ends of the second retaining rod 217, the first retaining rod 220 can slide in the long slot hole 224.2, the driving gear 218 is positioned at the lower side between the first retaining rod 220 and the second retaining rod 217, the two driving auxiliary gears 218., and both ends of the driving gear 218 are also rotatably connected with the second retaining rod 217 through two retaining pieces 219, so that the driving pinion 218.1 is always meshed with the transmission pinion 217.1, an annular groove is arranged in the middle of the driven gear 216 to prevent interference with the driving gear 218 when the feeding gear is changed, the driven gear 216 is positioned on the upper side between the first retaining rod 220 and the second retaining rod 217, the two driven pinions 216.1 are coaxially and fixedly installed at both ends of the driven gear 216 respectively, both ends of the driven gear 216 are rotatably connected with the first retaining rod 220 through the two retaining pieces 219, and both ends of the driven gear 216 are also rotatably connected with the second retaining rod 217 through the two retaining pieces 219, so that the driven pinion 216.1 is always meshed with the transmission pinion 217.1.

The left end of the pull rod 221 and the first holding rod 220 form a rotating pair, a spring 222 is arranged between the left end of the pull rod 221 and the right side of the sliding frame 224, the right end of the pull rod 221 and the upper end of the shift lever 223 form a rotating pair, and the lower end of the shift lever 223 is provided with a cross bar structure convenient for holding by hand.

In the initial state, the shift lever 223 is in the vertical state, the pull rod 221 moves to the left under the elastic force of the spring 222, so that the first holding rod 220 slides to the left in the slotted hole 224.2, the driving gear 218 moves downwards and engages with one gear of the first gear tower 210, and the driven gear 216 moves upwards and engages with a corresponding one gear of the second gear tower 209 under the pushing force of the eight holding pieces 219.

The motor 205 can drive the sanding head 205.2 to rotate, thereby realizing the surface finishing of the mold.

The retainer 205.1 may securely connect the sanding head 205.2 to the output shaft of the motor 205. after loosening the retainer 205.1, the sanding head 205.2 may be removed and replaced with another type of sanding head depending on the mold material and surface characteristics.

When the surface of the mold is modified, firstly, the height of the sliding sleeve 103 in the positioning frame mechanism 1 and the rotation amount of each joint need to be adjusted, so that the polishing head 205.2 is aligned to the position of the surface of the mold to be modified, and then the hand wheel 212 is rotated to feed the polishing head 205.2 forward, so that the surface of the mold is gradually repaired.

After the handwheel 212 is rotated clockwise, the first bevel gear 215 drives the first gear tower 210 to rotate clockwise through the second bevel gear 211, the first gear tower 210 drives the driving gear 218 to rotate anticlockwise through gear meshing, so that the driving pinion 218.1 rotating anticlockwise drives the driven pinion 216.1 to rotate anticlockwise through the gear meshing relationship between the driving pinion 217.1 and the driven pinion 216.1, the driven pinion 216.1 drives the second gear tower 209 and the third bevel gear 208 to rotate clockwise through the gear meshing relationship between the driven gear 216 and the second gear tower 209, the third bevel gear 208 drives the fourth bevel gear 206 and the worm 207 to rotate clockwise, the worm 207 drives the worm wheel 202 and the threaded shaft 203 to rotate clockwise, the moving shaft 204 moves rightwards under the transmission effect of the threaded pair, so that the polishing head 205.2 moves rightwards to feed, and the surface of the mold is trimmed; the retraction of the sanding head 205.2 may be accomplished by turning the handwheel 212 counterclockwise.

When the transmission ratio needs to be increased to slow down the feeding speed, the shift lever 223 is pulled upwards to be in a horizontal state, in the process, the pull rod 221 pulls the first retaining rod 220 to move rightwards, under the action of the pulling force of the eight retaining pieces 219, the driving gear 218 moves upwards and is disengaged from the gear on the first gear tower 210, the driven gear 216 moves downwards and is disengaged from the gear on the second gear tower 209, then the shift lever 223 moves rightwards to a proper gear, the top ball 214 is clamped into the positioning hole 224.4 to accurately position the sliding frame 224, the shift lever 223 is pulled downwards to be in a vertical state, at the moment, the driving gear 218 is engaged with the smaller gear on the first gear tower 210, the driven gear 216 is engaged with the larger gear on the second gear tower 209, so that the transmission ratio between the first gear tower 210 and the second gear tower 209 is increased, and the feeding speed of the polishing head 205.2 is slowed down; conversely, moving the position of the lever 223 to the left, the transmission ratio may be decreased to increase the feed speed of the sanding head 205.2.

The feed gear of the trimmer head mechanism 2 can be indicated on the gear scale 201.3 by the gear pointer 224.3.

The references to "front", "back", "left", "right", etc., are to be construed as references to orientations or positional relationships based on the orientation or positional relationship shown in the drawings or as orientations and positional relationships conventionally found in use of the product of the present invention, and are intended to facilitate the description of the invention and to simplify the description, but do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and is therefore not to be construed as limiting the invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

Claims

1. The utility model provides a repair lathe on mould surface, includes locating rack mechanism (1) and repaiies first mechanism (2), its characterized in that: the positioning frame mechanism (1) has six spatial degrees of freedom, each movable joint is provided with a graduated scale, and the trimming head mechanism (2) adopts five-gear variable-speed transmission and is fixedly arranged at the tail end of the positioning frame mechanism (1) for repairing the surface of a mold;

the positioning frame mechanism (1) comprises a base (101), a positioning sleeve (102), a sliding sleeve (103), an upright post (104), a second screw (105), a pointer sleeve (106), a fourth screw (107), a cross arm (108), a third screw (109), a first screw (110), a sixth screw (111), a swinging frame (112), a swinging rod (113), a fifth screw (114), a nut (115) and a swinging head (116), wherein the base (101) is fixedly arranged on the ground, the upright post (104) is fixedly connected with the base (101), the sliding sleeve (103) can move and rotate on the upright post (104) through the pointer sleeve (106) and is locked by the third screw (109), the positioning sleeve (102) and the first screw (110) are convenient for realizing the height positioning of the sliding sleeve (103), the cross arm (108) and the sliding sleeve (103) form a rotating pair, and are locked by the second screw (105), the transverse swing rod (113) and the cross arm (108) can form a rotation pair and are locked by a fourth screw (107), the swing frame (112) and the transverse swing rod (113) can form a rotation pair and are locked by a fifth screw (114), and the swing head (116) and the swing frame (112) can form a rotation pair and are locked by a sixth screw (111);

the trimming head mechanism (2) is fixedly connected with the tail end of the positioning frame mechanism (1) and comprises a shell (201), a worm wheel (202), a threaded shaft (203), a moving shaft (204), a motor (205), a clamping piece (205.1), a polishing head (205.2), a fourth bevel gear (206), a worm (207), a third bevel gear (208), a second gear tower (209), a first gear tower (210), a second bevel gear (211), a hand wheel (212), a rear cover (213), a top ball (214), a first bevel gear (215), a driven gear (216), a driven pinion (216.1), a second retaining rod (217), a transmission pinion (217.1), a driving gear (218), a driving pinion (218.1), a retaining sheet (219), a first retaining rod (220), a pull rod (221), a spring (222), a shifting rod (223) and a sliding frame (224), wherein the shell (201) is a supporting main body, the motor (205) drives the polishing head (205.2) to rotate through the clamping piece (205.1), the surface of the die is trimmed, and the grinding head (205.2) can be fed and retracted by rotating a hand wheel (212); a five-gear variable transmission mechanism consisting of a worm wheel (202), a threaded shaft (203), a moving shaft (204), a fourth bevel gear (206), a worm (207), a third bevel gear (208), a second gear tower (209), a first gear tower (210), a second bevel gear (211), a hand wheel (212), a rear cover (213), a first bevel gear (215), a driven gear (216), a driven pinion (216.1), a second retaining rod (217), a transmission pinion (217.1), a driving gear (218), a driving pinion (218.1), a retaining sheet (219), a first retaining rod (220), a pull rod (221), a spring (222), a shift lever (223) and a sliding frame (224) can adjust the transmission ratio according to the feeding requirement, and can adopt a faster gear to feed during idle stroke so as to shorten the moving time of a polishing head, when the surface of the die is trimmed, the die can be fed by a slower gear, so that the machining quality of the surface of the die is improved.

2. A machine tool for repairing a surface of a mold as defined in claim 1, wherein: the base (101) is fixedly arranged on the ground through foundation bolts and provides stable support for the positioning frame mechanism (1), the lower end of the upright post (104) is fixedly arranged on the upper side of the base (101) through screws and enables the upright post (104) to keep a vertical state, the front side surface of the upright post (104) is provided with a first scale (104.1), the left side of the upright post (104) is vertically provided with a guide groove (104.2), the pointer sleeve (106) is of an open cylindrical structure, the upper end of the pointer sleeve is provided with a third pointer (106.1), the inner side of the third pointer is longitudinally provided with a guide bar, the pointer sleeve (106) and the upright post (104) are coaxially arranged, the guide bar is arranged in the guide groove (104.2), so that the pointer sleeve (106) and the upright post (104) form a moving pair, the upper end of the sliding sleeve (103) is provided with a third scale (103.2), the left side of the sliding sleeve is provided with a fan-shaped structure, the fan-shaped structure is provided with a second scale (103.1) and an arc, the rotating angle of the sliding sleeve (103) relative to the pointer sleeve (106) can be indicated on a third scale (103.2) by a third pointer (106.1), the sliding sleeve (103) can be clamped by two third screws (109) and fixed on the pointer sleeve (106) on the upright post (104) so as to realize the rotation locking and height positioning of the sliding sleeve (103), the positioning sleeve (102) is of an open circular ring structure, the positioning sleeve (102) and the upright post (104) are coaxially mounted and can slide on the upright post (104), a groove is formed in the plane of the upper end of the positioning sleeve (102) so as to facilitate reading of the first scale (104.1), and the fixing of the positioning sleeve (102) on the upright post (104) can be realized by screwing the first screw (110);

because the weight of the accessory connecting part of the sliding and rotating sleeve (103) is large, and accurate height positioning is not convenient to directly carry out, when the height of the sliding and rotating sleeve (103) needs to be adjusted, the first screw (110) is firstly unscrewed, the positioning sleeve (102) is moved to enable the upper end plane of the positioning sleeve to move to a target scale, the first screw (110) is locked, the positioning sleeve (102) is fastened on the upright post (104), then the two third screws (109) are unscrewed, the sliding and rotating sleeve (103) is moved downwards to enable the lower end plane of the sliding and rotating sleeve (103) to be tightly attached to the upper end plane of the positioning sleeve (102), and the two third screws (109) are locked, so that the accurate height adjustment of the sliding and rotating sleeve (103).

3. A machine tool for repairing a surface of a mold as defined in claim 1, wherein: the left end of the cross arm (108) is of an open structure and is provided with a second pointer (108.3), the right end of the cross arm is provided with a cross arm disc (108.1) and a fourth pointer (108.2), the left side of the cross arm (108) and the sliding sleeve (103) form a rotation pair, a second screw (105) can penetrate through an arc-shaped hole in the left side of the sliding sleeve (103) to enable the left end of the cross arm (108) to clamp a sector structure in the left side of the sliding sleeve (103), so that the rotation locking of the cross arm (108) is realized, the rotation angle of the cross arm (108) relative to the sliding sleeve (103) can be indicated on a second scale (103.1) through the second pointer (108.3), three arc-shaped holes are uniformly distributed in the circumferential direction on the cross arm disc (108.1), an upper dial (113.1) is arranged at the upper end of the cross arm (113), a fourth scale and three threaded holes are uniformly distributed in the circumferential direction are arranged on the upper dial (113.1), the upper dial (113.1) can form a rotation pair with the, the rotating angle of the transverse swing rod (113) relative to the cross arm (108) can be indicated on a fourth scale by a fourth pointer (108.2), the lower end of the transverse swing rod (113) is provided with a lower dial (113.2), the lower dial (113.2) is provided with a fifth scale and three threaded holes which are uniformly distributed in the circumferential direction, the left side of the swing frame (112) is provided with a swing frame disc (112.2) and a fifth pointer (112.3), the upper side of the swing frame disc is provided with a sixth pointer (112.1), the upper side of the swing frame disc (112.2) is uniformly distributed with three arc-shaped holes in the circumferential direction, the swing frame disc (112.2) and the lower dial (113.2) can form a rotating pair and can be locked by three fifth screws (114), the rotating angle of the swing frame (112) relative to the transverse swing rod (113) can be indicated on the fifth scale by the fifth pointer (112.3), the upper end of the swing head (116) is in a semi-circular plate structure, the semi-circular plate structure and the rotating pair are arranged on the semi-circular plate structure and the swing frame (112), the sixth screw (111) penetrates through an arc-shaped hole in the semicircular plate structure and then forms a thread pair with the swing frame (112), the rotation of the swing head (116) relative to the swing frame (112) can be locked by screwing the sixth screw (111), the rotation angle of the swing head (116) relative to the swing frame (112) can be indicated on a sixth scale (116.1) by a sixth pointer (112.1), a threaded rod (116.2) is arranged at the lower end of the swing head (116) and used for connecting expansion equipment, and a nut (115) and the threaded rod (116.2) form a thread pair for locking the expansion equipment.

4. A machine tool for repairing a surface of a mold as defined in claim 1, wherein: the right end of the shell (201) is provided with an internal spline (201.1), the side surface of the shell is provided with a transverse slot (201.2) and gear scales (201.3), the upper side of the transverse slot (201.2) is provided with five top beads (214), each top bead (214) corresponds to one gear and is used for accurately positioning a sliding frame (224), two side walls of the inner part of the shell are horizontally provided with four guide rails, a rear cover (213) is fixedly arranged at the left end of the shell (201) through screws, a threaded hole (213.1) is arranged on the rear cover (213), the threaded hole (213.1) and a threaded rod (116.2) form a thread pair and are locked through a nut (115) to form a double-nut anti-loosening structure, so that the fastening connection of the trimming head mechanism (2) and the tail end of the positioning frame mechanism (1) is realized, a hand wheel (212) is arranged at the upper side of the shell (201) and forms a rotation pair, a first bevel gear (215, the screw shaft (203) is arranged in the shell (201) and forms a rotating pair with the shell (201) through two bearings, the worm wheel (202) is coaxially and tightly connected with the left end of the screw shaft (203), the worm (207) is horizontally arranged in the shell (201) and forms a rotating pair, the worm (207) is meshed with the worm wheel (202) to form a worm and gear transmission structure, the fourth bevel gear (206) is coaxially and tightly arranged at the left end of the worm (207), the polishing head (205.2) is tightly connected with an output shaft of the motor (205) through a clamping piece (205.1), the motor (205) is fixedly arranged at the right end of the moving shaft (204), an external spline arranged at the left end of the moving shaft (204) is matched and arranged with an internal spline (201.1) at the right end of the shell (201), so that the moving shaft (204) and the shell (201) form a moving pair, a threaded hole arranged in the moving shaft (204) is matched and arranged at the right end of the screw, after the threaded shaft (203) rotates, the movable shaft (204) can be driven to move rightwards and leftwards, so that the feeding and retreating actions of the polishing head (205.2) are realized.

5. A machine tool for repairing a surface of a mold as defined in claim 1, wherein: the first gear tower (210) is provided with a five-layer gear structure, the reference circle diameters of the five-layer gear structure are in an equal-difference number series and form five gears, the first gear tower (210) is obliquely arranged in the shell (201) and forms a revolute pair, the large end of the first gear tower is towards the left and the small end of the first gear tower is towards the right, a second bevel gear (211) is coaxially and fixedly connected with the left end of the first gear tower (210), the second bevel gear (211) and a first bevel gear (215) form gear meshing transmission, the parameters of the five-layer gear structure arranged on a second gear tower (209) are the same as those of the five-layer gear structure arranged on the first gear tower (210), the second gear tower (209) is obliquely arranged in the shell (201) and forms a revolute pair, the large end of the second gear tower (209) is towards the right and the small end of the first gear tower (210), the central axes of the second gear tower (209) are parallel to each other, a third bevel gear, the third bevel gear (208) and the fourth bevel gear (206) form gear meshing transmission;

the sliding frame (224) is arranged inside the shell (201), the right end of the sliding frame is positioned in the transverse groove (201.2), two sliding block structures arranged at the left end of the sliding frame (224) and two sliding block structures arranged at the right end of the sliding frame (224) are respectively matched and arranged with four guide rails on two side walls inside the shell (201), so that the sliding frame (224) and the shell (201) form a moving pair, a round hole (224.1) and a long groove hole (224.2) are arranged at the position, close to the middle, of the sliding frame (224), a gear pointer (224.3) and a positioning hole (224.4) are arranged at the right end of the sliding frame, the second retaining rod (217) is arranged in the round hole (224.1) to form a rotating pair, two transmission auxiliary gears (217.1) are respectively and coaxially and fixedly arranged at two ends of the second retaining rod (217), the first retaining rod (220) can slide in the long groove hole (224.2), the driving gear (218) is positioned at the lower side between the first retaining rod (220) and the second retaining, the two ends of the driving gear (218) are rotatably connected with the first holding rod (220) through two holding pieces (219), the two ends of the driving gear (218) are also rotatably connected with the second holding rod (217) through the two holding pieces (219), so that the driving pinion (218.1) is always meshed with the transmission pinion (217.1), an annular groove is arranged in the middle of the driven gear (216) to prevent interference with the driving gear (218) when the feeding gear is changed, the driven gear (216) is positioned on the upper side between the first holding rod (220) and the second holding rod (217), the two driven pinions (216.1) are coaxially and fixedly arranged at the two ends of the driven gear (216), the two ends of the driven gear (216) are rotatably connected with the first holding rod (220) through the two holding pieces (219), and the two ends of the driven gear (216) are also rotatably connected with the second holding rod (217) through the two holding pieces (219), the driven pinion (216.1) is always meshed with the transmission pinion (217.1);

the left end of the pull rod (221) and the first holding rod (220) form a rotating pair, a spring (222) is arranged between the left end of the pull rod (221) and the right side of the sliding frame (224), the right end of the pull rod (221) and the upper end of the shifting rod (223) form a rotating pair, and the lower end of the shifting rod (223) is provided with a cross rod structure convenient for holding;

in the initial state, the shifting lever (223) is in a vertical state, the pull rod (221) moves leftwards under the elastic force of the spring (222), so that the first retaining rod (220) slides leftwards in the long slotted hole (224.2), under the thrust action of the eight retaining pieces (219), the driving gear (218) moves downwards and is meshed with one gear of the first gear tower (210), and the driven gear (216) moves upwards and is meshed with a corresponding gear of the second gear tower (209).

6. A machine tool for repairing a surface of a mold as defined in claim 1, wherein: the motor (205) can drive the grinding head (205.2) to rotate, so that the surface of the die can be trimmed;

the clamping piece (205.1) can tightly connect the polishing head (205.2) with the output shaft of the motor (205), and the polishing head (205.2) can be taken down and replaced by other types of polishing heads according to the material and surface characteristics of the die after the clamping piece (205.1) is unscrewed;

when the surface of a die is trimmed, firstly, the height of a sliding sleeve (103) in a positioning frame mechanism (1) and the rotation amount of each joint need to be adjusted, so that a polishing head (205.2) is aligned to the position of the surface of the die, which needs to be corrected, and then a hand wheel (212) is rotated to feed the polishing head (205.2) forwards, so that the repair of the surface of the die is gradually completed;

after the hand wheel (212) is rotated clockwise, the first bevel gear (215) drives the first gear tower (210) to rotate clockwise through the second bevel gear (211), the first gear tower (210) drives the driving gear (218) to rotate anticlockwise through gear meshing, so that the driving pinion (218.1) rotating anticlockwise drives the driven pinion (216.1) to rotate anticlockwise through the gear meshing relationship between the driving pinion (217.1) and the driven pinion (216.1), the driven pinion (216.1) drives the second gear tower (209) and the third bevel gear (208) to rotate clockwise through the gear meshing relationship between the driven gear (216) and the second gear tower (209), the third bevel gear (208) drives the fourth bevel gear (206) and the worm (207) to rotate clockwise, the worm (207) drives the worm gear (202) and the threaded shaft (203) to rotate clockwise, and under the transmission effect of the threaded pair, the moving shaft (204) moves rightwards, so that the polishing head (205.2) moves rightwards and feeds, and the surface of the die is trimmed; the backward movement of the polishing head (205.2) can be realized by rotating the hand wheel (212) anticlockwise;

when the transmission ratio needs to be increased to slow down the feeding speed, the shifting lever (223) is firstly pulled upwards to be in a horizontal state, in the process, the pull rod (221) pulls the first retaining rod (220) to move rightwards, under the action of the pulling force of the eight retaining pieces (219), the driving gear (218) moves upwards and is disengaged from the gear on the first gear tower (210), the driven gear (216) moves downwards and is disengaged from the gear on the second gear tower (209), then the shifting lever (223) moves rightwards to a proper gear, the top ball (214) is clamped into the positioning hole (224.4) to accurately position the sliding frame (224), the shifting lever (223) is pulled downwards to be in a vertical state, at the moment, the driving gear (218) is engaged with the smaller gear on the first gear tower (210), the driven gear (216) is engaged with the larger gear on the second gear tower (209), and therefore the transmission ratio between the first gear tower (210) and the second gear tower (209) is increased, -slowing down the feed speed of the sanding head (205.2); conversely, by moving the position of the shift lever (223) to the left, the transmission ratio can be reduced to increase the feed speed of the sanding head (205.2);

the feed gear of the trimming head mechanism (2) can be indicated on the gear scale (201.3) by a gear pointer (224.3).