CN217196989U

CN217196989U - Mask folding edge welding machine

Info

Publication number: CN217196989U
Application number: CN202122956924.7U
Authority: CN
Inventors: 黄涛
Original assignee: Anshun Ankangfu Medical Technology Co ltd
Current assignee: Anshun Ankangfu Medical Technology Co ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-08-16
Anticipated expiration: 2031-11-29

Abstract

The utility model discloses a folding limit machine that welds of gauze mask, which comprises a bod, the feed inlet has been seted up at the upper end middle part of organism, the upper end of organism is provided with two slide rails, and the both ends of two slide rails are provided with two baffles jointly, and common sliding connection has the base on two slide rails, the upper end both sides of base all are provided with the standing groove, seted up two rectangular mouths on the base, two rectangular mouths set up the middle part in two standing grooves respectively. The utility model discloses can upgrade the folding limit machine of welding of gauze mask that the gauze mask of a traditional gauze mask adds the station into the folding limit machine of welding of gauze mask that two gauze masks add the station, can drive simultaneously and make two gauze masks add the station and carry out reciprocal switching, and can make the gauze mask add the station when switching to the relevant position and stop, provide time for the folding of gauze mask, thereby can be when the folding limit machining effect that welds of guarantee gauze mask, improve the machining efficiency of the folding limit machine that welds of gauze mask, make the production efficiency of gauze mask obtain improving.

Description

Mask folding edge welding machine

Technical Field

The utility model relates to a gauze mask production technical field especially relates to a folding limit machine that welds of gauze mask.

Background

Gauze mask mainly comprises gauze mask body and ear line, in the gauze mask production, need fix two ear lines on the gauze mask body through melting welding process, the protective effect is stronger in the gauze mask is KN95 and N95 etc, its gauze mask body has concave surface spatial structure usually, need weld the limit after carrying out the fifty percent discount through folding the plane gauze mask body that the limit machine will cut in process of production, but current folding limit machine that welds only has a gauze mask and adds the station, efficiency is lower in the gauze mask course of working, thereby the production efficiency who leads to the gauze mask is lower, so need improve.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming current folding limit machine of welding and only having a gauze mask processing position, adding man-hour machining efficiency lower to the gauze mask, the work efficiency that leads to the folding limit machine of welding of gauze mask is lower, influences the not enough of gauze mask production efficiency, and the folding limit machine of welding of a gauze mask that proposes.

In order to realize the purpose, the utility model adopts the following technical scheme:

a mask folding edge welding machine comprises a machine body, wherein a feed inlet is formed in the middle of the upper end of the machine body, two slide rails are arranged at the upper end of the machine body, two baffle plates are arranged at two ends of the two slide rails together, a base is connected to the two slide rails in a sliding mode together, two placing grooves are formed in two sides of the upper end of the base, two strip-shaped openings are formed in the base and are arranged in the middle of the two placing grooves respectively, the strip-shaped openings and the feed inlet are arranged correspondingly, a threaded sleeve is fixedly connected to the middle of one side of the base, a fixing ring is fixedly connected to one side of the threaded sleeve, rack groups are fixedly connected to the opposite inner walls of the fixing ring, a power mechanism is arranged on one side of the machine body, an incomplete gear is arranged on the power mechanism, the incomplete gear is arranged in the fixing ring, and the incomplete gear and the two rack groups are arranged correspondingly, the both sides of organism all are fixed with the loading board, are equipped with anti-skidding mechanism on two loading boards jointly, the last lead screw that is equipped with of anti-skidding mechanism, the both ends of lead screw all are rotated and have been cup jointed the fixed block, and the equal fixed connection of two fixed blocks is on the organism, threaded sleeve pipe thread cup joints on the lead screw.

Preferably, for the removal for the base provides power, realize the reciprocal purpose of switching of two standing grooves, power unit includes the fixed box of fixed connection in organism one side, fixed mounting has servo motor in the fixed box, servo motor's output shaft end runs through the upper end of fixed box and fixed connection in the middle part of the lower extreme of incomplete gear.

Preferably, in order when the base is not promoted, restrict the removal of base, make base more stable when not promoted, anti-skidding mechanism includes two telescopic links of fixed connection in two loading board one sides respectively, the equal fixedly connected with friction member of one end of two telescopic links, and two friction members contradict respectively in both ends one side of lead screw, have all cup jointed the spring on two telescopic links, and the one end of two springs is fixed connection in one side of two loading boards respectively, and the other end of two springs is fixed connection respectively on two friction members.

Preferably, in order to press the gauze mask in the standing groove and enter into the organism and weld the limit, press the gauze mask simultaneously and enter into the organism when, can fold the gauze mask from the middle part and press and enter into the organism, realize that the gauze mask carries out automatic folding earlier when welding the limit, the upper end of organism is provided with elevating gear, the last lifter plate that is provided with of elevating gear, the lower extreme of lifter plate is provided with the folded sheet, the folded sheet corresponds the top that sets up at the feed inlet.

Preferably, in order to adjust the horizontal angle of the machine body, the machine body is more stable when in use, the four corners of the lower end of the machine body are provided with supporting screws, and the lower ends of the supporting screws are sleeved with pad pieces in a threaded manner.

Compared with the prior art, the beneficial effects of the utility model are that:

1. through the use of the power mechanism, the fixing ring, the rack groups and the base, incomplete gear rotation can be driven by the power mechanism, the incomplete gear rotation can respectively push two sets of rack groups, the two sets of rack groups are respectively pushed to drive the fixing ring to move in a reciprocating manner, meanwhile, the fixing ring can stay after moving to a limit position on one side and then move to the other side, so that the base can be driven to move in a reciprocating manner, two mask machining positions are arranged on the base and can be switched in a reciprocating manner, the working efficiency of the mask folding and edge welding machine can be improved, and the production efficiency of the masks can be increased;

2. by using the anti-slip mechanism, the movement of the base can be limited when the incomplete gear is not meshed with the rack assembly, so that a mask processing position on the base can be kept stable when the mask processing position is not pushed, the stability of the mask during processing on the folding edge welding machine is effectively guaranteed, and the processing effect and the processing efficiency of the mask folding edge welding machine can be improved;

to sum up, the utility model discloses can add the folding limit machine that welds of gauze mask of station to two gauze masks with the folding limit machine that welds of gauze mask of traditional gauze mask, can drive simultaneously and make two gauze masks add the station and carry out reciprocal switching to can make the gauze mask add the station and stop when switching to relevant position, provide time for the folding of gauze mask, thereby can be when the folding limit machining effect that welds of guarantee gauze mask, improve the machining efficiency of the folding limit machine that welds of gauze mask, make the production efficiency of gauze mask obtain improving.

Drawings

Fig. 1 is a top view of the present invention;

FIG. 2 is a schematic view of the connection structure of the present invention;

FIG. 3 is an enlarged view of the present invention at A;

fig. 4 is a schematic structural view of the fixing ring of the present invention.

In the figure: the device comprises a machine body 1, a lifting device 2, a lifting plate 3, a folding plate 4, a sliding rail 5, a baffle 6, a base 7, a placing groove 8, a long strip opening 9, a feed inlet 10, a threaded sleeve 11, a fixing ring 12, a rack group 13, an incomplete gear 14, a servo motor 15, a fixing box 16, a fixing block 17, a screw rod 18, a bearing plate 19, a telescopic rod 20, a friction piece 21, a spring 22, a support screw 23 and a cushion piece 24.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples, which are provided for the purpose of illustration only and are not intended to limit the scope of the invention.

Example 1

Referring to fig. 1-4, a mask folding and edge welding machine comprises a machine body 1, the machine body 1 is a device capable of automatically welding a mask body and an ear line, a feed inlet 10 is arranged in the middle of the upper end of the machine body 1, the mask body can be conveyed into the machine body 1 from the feed inlet 10 for edge welding processing through a matching component on the machine body 1, a lifting device 2 is arranged at the upper end of the machine body 1, a lifting plate 3 is arranged on the lifting device 2, a folding plate 4 is arranged at the lower end of the lifting plate 3, the folding plate 4 is correspondingly arranged above the feed inlet 10, the lifting device 2 is connected with the matching component, so that stable operation is facilitated, a program can be set, automatic operation is realized, the lifting plate 3 can be driven to lift through the operation of the lifting device 2, the lifting plate 3 can drive the folding plate 4 to lift, when the mask body moves to the feed inlet 10, the mask body can be inserted into the feed inlet 10 through the lowering of the folding plate 4, and when this integument of gauze mask inserted feed inlet 10 in, can make the gauze mask body begin to fold from the middle part to can reach and carry out folding effect to the gauze mask, carry the gauze mask body after folding in 1 organism from feed inlet 10, can weld the ear wire on the gauze mask body through the function of each part in the organism 1, realize then carrying out the folding mesh of welding the limit processing to the gauze mask.

Referring to fig. 1 and 2, two slide rails 5 are disposed at the upper end of a machine body 1, two ends of the two slide rails 5 are commonly provided with two baffles 6, a base 7 is commonly slidably connected to the two slide rails 5, the base 7 can slide on the upper end of the machine body 1 through the two slide rails 5, the two ends of the two slide rails 5 can be blocked by the two baffles 6, so as to prevent the base 7 from falling off when sliding on the two slide rails 5, the base 7 can move on the two slide rails 5 in parallel, and the rotation of the base 7 can be limited by the two slide rails 5, so that the base 7 can move more stably, both sides of the upper end of the base 7 are provided with placing grooves 8, the base 7 is provided with two strip openings 9, the two strip openings 9 are respectively disposed at the middle parts of the two placing grooves 8, the strip openings 9 and the feed inlet 10 are correspondingly disposed, the placing grooves 8 are used for placing a mask body, when the base 7 moves, can drive two standing groove 8 and remove, reciprocating motion through base 7, can reciprocate two standing groove 8 and switch, when one of them standing groove 8 drove the gauze mask body and removes relevant position, rectangular mouth 9 in one of them standing groove 8 just in time is located the top of feed inlet 10, 4 decline of folded sheet can be with the gauze mask body in the standing groove 8 press from the middle part in entering into rectangular mouth 9, again from rectangular mouth 9 enter into feed inlet 10 in, when the gauze mask body enters into rectangular mouth 9, the gauze mask body is folded from the middle part, thereby can carry the gauze mask body after folding in organism 1 from feed inlet 10.

Referring to fig. 1, 2 and 4, a threaded sleeve 11 is fixedly connected to the middle of one side of the base 7, a fixing ring 12 is fixedly connected to one side of the threaded sleeve 11, the fixing ring 12 can move to drive the threaded sleeve 11 to move, the threaded sleeve 11 can move to drive the base 7 to move, the opposite inner walls of the fixed ring 12 are fixedly connected with rack groups 13, each rack group 13 is composed of a plurality of teeth, when the rack groups 13 are pushed, can drive the fixed ring 12 to move, the two groups of rack sets 13 are positioned on the opposite inner walls of the fixed ring 12, when one group of the rack bar groups 13 is pushed, the fixing ring 12 can be driven to move to one side, and when the other group of the rack bar groups 13 is pushed, can drive the fixed ring 12 to move towards the other side, so that the fixed ring 12 realizes the reciprocating motion effect, therefore, the base 7 can be driven to reciprocate through the threaded sleeve 11, and the purpose of reciprocating switching of the two placing grooves 8 is achieved.

Referring to fig. 1, 2 and 4, a power mechanism is disposed on one side of a machine body 1, an incomplete gear 14 is disposed on the power mechanism, the incomplete gear 14 is disposed in a fixing ring 12, when the power mechanism operates, the incomplete gear 14 can be driven to rotate, the incomplete gear 14 is a component having a plurality of teeth on one side, the power mechanism includes a fixing box 16 fixedly connected to one side of the machine body 1, a servo motor 15 is fixedly mounted in the fixing box 16, an output shaft of the servo motor 15 penetrates through an upper end of the fixing box 16 and is fixedly connected to a lower middle portion of the incomplete gear 14, the fixing box 16 can bear the servo motor 15, the servo motor 15 is mounted on one side of the machine body 1, the servo motor 15 is connected with a matching component, stable operation is facilitated, a program can be set, automatic operation is achieved, the incomplete gear 14 can be driven to rotate through operation of the servo motor 15, the incomplete gear 14 and the two rack groups 13 are correspondingly arranged, the incomplete gear 14 can be meshed with one of the rack groups 13 when rotating to a corresponding position, after the incomplete gear 14 is pushed to the corresponding position, the incomplete gear can not be meshed with the rack group 13, when the incomplete gear 14 is not meshed with the rack group 13, the fixed ring 12 does not move, the base 7 can be made to stop for a short time, when the incomplete gear 14 rotates to the other rack group 13, the incomplete gear can be pushed to the other rack group 13 to move towards the other direction through the meshing with the other rack group 13, the base 7 can be made to move back, and the purpose of reciprocating motion of the base 7 can be achieved.

Referring to fig. 1-4, both sides of the machine body 1 are fixed with bearing plates 19, the two bearing plates 19 are provided with an anti-skid mechanism together, part of components on the anti-skid mechanism can be loaded through the bearing plates 19, the components on the anti-skid mechanism are arranged on the machine body 1, the anti-skid mechanism is provided with a lead screw 18, both ends of the lead screw 18 are rotatably sleeved with fixing blocks 17, the two fixing blocks 17 are fixedly connected to the machine body 1, a threaded sleeve 11 is in threaded sleeve connection with the lead screw 18, the lead screw 18 can be mounted on the machine body 1 through the two fixing blocks 17, the lead screw 18 can rotate on the two fixing blocks 17, the lead screw 18 is provided with spiral threads, the threaded sleeve 11 is provided with internal threads, when the base 7 drives the threaded sleeve 11 to move, the lead screw 18 can be pushed to rotate, and when the lead screw 18 is limited to rotate, the movement of the threaded sleeve 11 is limited, the anti-skid mechanism comprises two telescopic rods 20 respectively fixedly connected to one side of two bearing plates 19, one end of each telescopic rod 20 is fixedly connected with a friction piece 21, the two friction pieces 21 are respectively abutted to one side of two ends of a lead screw 18, the friction pieces 21 can be kept to stably move when moving through the telescopic rods 20, the telescopic rods 20 are telescopic parts, springs 22 are respectively sleeved on the two telescopic rods 20, one ends of the two springs 22 are respectively fixedly connected to one side of the two bearing plates 19, the other ends of the two springs 22 are respectively fixedly connected to the two friction pieces 21, the springs 22 have elasticity, the friction pieces 21 can be abutted to one side of two ends of the lead screw 18 through the springs 22, the friction pieces 21 abutted to one side of two ends of the lead screw 18 can limit the rotation of the lead screw 18 through friction force, when the threaded sleeve 11 is not driven to move, the friction force of the lead screw 18 can be applied through the friction pieces 21, the movement of the threaded sleeve 11 is limited, so that the threaded sleeve 11 and the base 7 are kept stable when not pushed, and the stability of the mask in the placing groove 8 during processing is effectively guaranteed.

Example 2

Referring to fig. 1 and 2, two slide rails 5 are disposed at the upper end of a machine body 1, two ends of the two slide rails 5 are commonly provided with two baffles 6, a base 7 is commonly slidably connected to the two slide rails 5, the base 7 can slide on the upper end of the machine body 1 through the two slide rails 5, the two ends of the two slide rails 5 can be blocked by the two baffles 6, so as to prevent the base 7 from falling off when sliding on the two slide rails 5, the base 7 can move on the two slide rails 5 in parallel, and the rotation of the base 7 can be limited by the two slide rails 5, so that the base 7 can move more stably, both sides of the upper end of the base 7 are provided with placing grooves 8, the base 7 is provided with two strip openings 9, the two strip openings 9 are respectively disposed at the middle parts of the two placing grooves 8, the strip openings 9 and the feed inlet 10 are correspondingly disposed, the placing grooves 8 are used for placing a mask body, when the base 7 moves, can drive two standing grooves 8 and remove, reciprocating motion through base 7, can reciprocate two standing grooves 8 and switch, when one of them standing groove 8 drove the gauze mask body and moves the relevant position, rectangular mouth 9 in one of them standing groove 8 just in time is located the top of feed inlet 10, 4 descends and to press the gauze mask body in the standing groove 8 from the middle part and enter into rectangular mouth 9 in, again from rectangular mouth 9 enter into feed inlet 10 in, when the gauze mask body enters into rectangular mouth 9 in, the gauze mask body begins to fold from the middle part, thereby can be after folding with the gauze mask body after the feed inlet 10 carry in the organism 1.

Referring to fig. 1, 2 and 4, a threaded sleeve 11 is fixedly connected to the middle of one side of the base 7, a fixing ring 12 is fixedly connected to one side of the threaded sleeve 11, the fixing ring 12 can move to drive the threaded sleeve 11 to move, the threaded sleeve 11 can move to drive the base 7 to move, the opposite inner walls of the fixed ring 12 are fixedly connected with rack groups 13, each rack group 13 is composed of a plurality of teeth, when the rack groups 13 are pushed, can drive the fixed ring 12 to move, the two groups of rack sets 13 are positioned on the opposite inner walls of the fixed ring 12, when one set of the rack set 13 is pushed, the fixing ring 12 can be driven to move to one side, and when the other set of the rack set 13 is pushed, can drive the fixed ring 12 to move towards the other side, so that the fixed ring 12 realizes the reciprocating motion effect, therefore, the base 7 can be driven to reciprocate through the threaded sleeve 11, and the purpose of reciprocating switching of the two placing grooves 8 is achieved.

Referring to fig. 1-4, both sides of the machine body 1 are fixed with bearing plates 19, the two bearing plates 19 are provided with an anti-skid mechanism together, part of components on the anti-skid mechanism can be loaded through the bearing plates 19, the components on the anti-skid mechanism are arranged on the machine body 1, the anti-skid mechanism is provided with a lead screw 18, both ends of the lead screw 18 are rotatably sleeved with fixing blocks 17, the two fixing blocks 17 are fixedly connected to the machine body 1, a threaded sleeve 11 is in threaded sleeve connection with the lead screw 18, the lead screw 18 can be mounted on the machine body 1 through the two fixing blocks 17, the lead screw 18 can rotate on the two fixing blocks 17, the lead screw 18 is provided with spiral threads, the threaded sleeve 11 is provided with internal threads, when the base 7 drives the threaded sleeve 11 to move, the lead screw 18 can be pushed to rotate, and when the lead screw 18 is limited to rotate, the movement of the threaded sleeve 11 is limited, the anti-skid mechanism comprises two telescopic rods 20 fixedly connected to one side of two bearing plates 19 respectively, one end of each telescopic rod 20 is fixedly connected with a friction piece 21, the two friction pieces 21 are respectively abutted to one side of two ends of a lead screw 18, the friction pieces 21 can be kept to stably move during moving through the telescopic rods 20, the telescopic rods 20 are telescopic parts, springs 22 are sleeved on the two telescopic rods 20 respectively, one ends of the two springs 22 are respectively and fixedly connected to one side of the two bearing plates 19, the other ends of the two springs 22 are respectively and fixedly connected to the two friction pieces 21, the springs 22 have elasticity, the friction pieces 21 can be abutted to one side of two ends of the lead screw 18 through the springs 22, the friction pieces 21 can limit the rotation of the lead screw 18 through friction force when abutting to one side of two ends of the lead screw 18, when the threaded sleeve 11 is not driven to move, the friction force of the lead screw 18 can be exerted on the lead screw through the friction pieces 21, the movement of the threaded sleeve 11 is limited, so that the threaded sleeve 11 and the base 7 are kept stable when not pushed, and the stability of the mask in the placing groove 8 during processing is effectively guaranteed.

Referring to fig. 2, the lower extreme four corners of organism 1 all is provided with supporting screw 23, and the equal screw thread of the lower extreme of supporting screw 23 has cup jointed pad 24, and pad 24 can go up and down through rotating on supporting screw 23, can adjust the support angle to organism 1 through the lift of pad 24 to can adjust the horizontal angle of organism 1, make organism 1 keep steady when the function, improve the stability of organism 1.

Compared with embodiment 1, the present embodiment can adjust the horizontal state of the machine body 1, so that the machine body 1 is more stable during operation.

The utility model discloses in, when the usual use: two mask bodies are placed in two placing grooves 8, a servo motor 15 is controlled to operate through a matched control device, the servo motor 15 drives an incomplete gear 14 to rotate, the incomplete gear 14 pushes one group of rack groups 13 to move, one group of rack groups 13 drives a fixing ring 12 to move, the fixing ring 12 drives a threaded sleeve 11 to move, the threaded sleeve 11 drives a base 7 to move, the base 7 drives two mask bodies in the two placing grooves 8 to move, when a long strip opening 9 in one placing groove 8 is positioned above a feed inlet 10, the incomplete gear 14 is not meshed with one group of rack groups 13, the base 7 stops moving, the lifting device 2 is controlled to operate through the matched control device, the lifting device 2 drives a lifting plate 3 to descend, the lifting plate 3 drives a folding plate 4 to descend, the folding plate 4 presses the mask body in one placing groove 8 into the long strip opening 9, rethread feed inlet 10 enters into organism 1 in, when the folded sheet 4 pressed the gauze mask body and entered into rectangular mouth 9 in, can make the gauze mask body fold, the gauze mask body that enters into in the organism 1 passes through the function of the interior supporting part of organism 1 with two ear wire welding on the gauze mask body, after the welding was accomplished, elevating gear 2 drives folded sheet 4 and rises, incomplete gear 14 rotates simultaneously and meshes with another group rack group 13, through the promotion to another group rack group 13, make base 7 drive two standing groove 8 and remove, long strip mouth 9 in another standing groove 8 removes the top of feed inlet 10, can realize the effect of two standing groove 8 reciprocal switchings, the processing production efficiency of gauze mask has been improved.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a mask folding edge welding machine, includes organism (1), its characterized in that: a feed inlet (10) is formed in the middle of the upper end of the machine body (1), two slide rails (5) are arranged at the upper end of the machine body (1), two baffle plates (6) are arranged at two ends of the two slide rails (5) together, a base (7) is connected to the two slide rails (5) together in a sliding manner, placing grooves (8) are formed in two sides of the upper end of the base (7), two strip openings (9) are formed in the base (7), the two strip openings (9) are respectively arranged in the middle of the two placing grooves (8), the strip openings (9) and the feed inlet (10) are arranged correspondingly, a threaded sleeve (11) is fixedly connected to the middle of one side of the base (7), a fixing ring (12) is fixedly connected to one side of the threaded sleeve (11), a rack group (13) is fixedly connected to the opposite inner wall of the fixing ring (12), and a power mechanism is arranged on one side of the machine body (1), be equipped with incomplete gear (14) on power unit, incomplete gear (14) set up in retainer plate (12), incomplete gear (14) and two rack group (13) correspond the setting, the both sides of organism (1) all are fixed with loading board (19), are equipped with anti-skidding mechanism on two loading boards (19) jointly, be equipped with lead screw (18) on the anti-skidding mechanism, fixed block (17) have all been cup jointed in the both ends of lead screw (18) rotation, and two equal fixed connection in fixed block (17) are on organism (1), threaded sleeve (11) screw thread cup joints on lead screw (18).

2. The mask folding and edge welding machine of claim 1, wherein: the power mechanism comprises a fixed box (16) fixedly connected to one side of the machine body (1), a servo motor (15) is fixedly mounted in the fixed box (16), and the tail end of an output shaft of the servo motor (15) penetrates through the upper end of the fixed box (16) and is fixedly connected to the middle of the lower end of the incomplete gear (14).

3. The mask folding and edge welding machine of claim 1, wherein: antiskid includes two telescopic links (20) of fixed connection respectively in two loading boards (19) one side, the equal fixedly connected with friction member (21) of one end of two telescopic links (20), two friction member (21) are contradicted respectively in both ends one side of lead screw (18), spring (22) have all been cup jointed on two telescopic links (20), the one end of two spring (22) is fixed connection respectively in one side of two loading boards (19), the other end difference fixed connection of two spring (22) is on two friction member (21).

4. The mask folding and edge welding machine of claim 1, wherein: the upper end of organism (1) is provided with elevating gear (2), be provided with lifter plate (3) on elevating gear (2), the lower extreme of lifter plate (3) is provided with folded sheet (4), folded sheet (4) correspond the top that sets up at feed inlet (10).

5. The mask folding and edge welding machine of claim 1, wherein: supporting screws (23) are arranged at four corners of the lower end of the machine body (1), and pad pieces (24) are sleeved at the lower ends of the supporting screws (23) in a threaded manner.