CN111570706B

CN111570706B - Forging and pressing feeding device based on material forming processing

Info

Publication number: CN111570706B
Application number: CN202010447507.7A
Authority: CN
Inventors: 花少震; 王陈东; 刘华博; 孟凡净
Original assignee: Henan Institute of Technology
Current assignee: Dragon Totem Technology Hefei Co ltd; Shandong Jinaoer Abrasive Co.,Ltd.
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2021-08-03
Anticipated expiration: 2040-05-25
Also published as: CN111570706A

Abstract

The invention discloses a forging and pressing feeding device based on material forming machining, which comprises a main body seat; the main body seat is welded with a feeding cylinder and is also connected with a clamping structure in a sliding manner; the clamping structure is provided with an adjusting structure, and the clamping structure is welded with a discharging structure; the clamping structure comprises guide plates, the two guide plates are respectively welded on the rotating seats of the two idler wheels, and the rear end surfaces of the two guide plates are both inclined structures, so that when the electric telescopic rod is contracted, the electric telescopic rod drives the clamping structure and the adjusting structure to move backwards, at the moment, the two guide plates with the inclined rear end surfaces are firstly contacted with the part main body, and further can play a role in guiding when the part main body is clamped in a sliding manner; the adjusting structure comprises a sliding seat, the sliding seat is welded on the top end face of the first sliding rail, the sliding seat is connected to the sliding seat rail seat in a sliding mode, the sliding seat rail seat forms an axial limiting structure of the adjusting structure, and the bottom end face of the main body seat is fixedly connected with an electric telescopic rod through a bolt.

Description

Forging and pressing feeding device based on material forming processing

Technical Field

The invention belongs to the technical field of forging feeding devices, and particularly relates to a forging feeding device based on material forming machining.

Background

Forging is the combination of forging and stamping, and is a forming method for obtaining a product with a required shape and size by applying pressure to a blank by using a hammer head, an anvil block, a punch head or through a die of a forging and stamping machine to generate plastic deformation. Feeding by using a feeding device is often needed during forging.

Chinese patent application CN200680050053.8 discloses a feeding device, the feeding device comprises a positive and negative winder (31), a linear body (51) for positive winding, a linear body (61) for reverse winding, a reciprocating body (71) and the like, wherein the linear body (51) for positive winding and the linear body (61) for reverse winding are connected with the reciprocating body (71), the winding amount and the unwinding amount of the drum (37) of the positive and negative winder (31) to the linear body (51) for positive winding and the unwinding amount of the linear body (61) for reverse winding are equal to each other, the drum (37) of the positive and negative winder (31) during winding rotation moves along the axial direction corresponding to the winding pitch and the unwinding pitch of the two linear bodies (51), thus, the high precision and the improvement of the durability and the compactness of the structure based on the quiet and stable operation state can be realized, and the high precision and the improvement of the durability based on the proper winding and unwinding of the linear body can be realized.

The feeding device similar to the above application currently has the following disadvantages:

firstly, the feeding device of the existing device generally realizes the feeding of parts through a mechanical hand type clamp, the mechanical hand of the device mostly realizes the clamping and moving actions through a plurality of telescopic cylinders, the cost is higher, and the clamping and feeding actions can not be realized only by one telescopic cylinder through structural improvement; second, current feed arrangement generally only can realize the feeding effect, and can not realize unloading and residue clearance function simultaneously, and it is unloaded and most sets up alone of residue clearance, has promoted the cost on the one hand, and on the other hand has also increased the occupation of whole space.

In view of the above, the present invention provides a forging and pressing feeding device based on material forming process, which is improved in view of the conventional structure and defects, so as to achieve the purpose of higher practical value.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a forging and pressing feeding device based on material forming processing, and aims to solve the problems that the feeding device generally realizes the feeding of parts through a mechanical hand type clamp, most of mechanical hands realize clamping and moving actions through a plurality of telescopic cylinders, the cost is high, the clamping and feeding actions cannot be realized through only one telescopic cylinder through structural improvement, and the whole space is occupied.

In order to achieve the purpose, the invention provides a forging and feeding device based on material forming processing, which comprises a main body seat; a feeding cylinder is welded on the main body seat, a part main body is placed in the feeding cylinder, and a clamping structure is connected to the main body seat in a sliding manner; the clamping structure is provided with an adjusting structure, and the clamping structure is welded with a discharging structure; the clamping structure comprises two guide plates, the two guide plates are welded on the rotating seats of the two idler wheels respectively, and the rear end surfaces of the two guide plates are both inclined structures, so that when the electric telescopic rod is contracted, the electric telescopic rod drives the clamping structure and the adjusting structure to move backwards, at the moment, the two guide plates with the inclined rear end surfaces are firstly contacted with the part main body, and further can play a role in guiding when the part main body is clamped in a sliding manner; the adjusting structure comprises a sliding seat, the sliding seat is welded on the top end face of the first sliding rail, the sliding seat is connected to the sliding seat rail seat in a sliding mode, and the sliding seat rail seat forms an axial limiting structure of the adjusting structure, so that the left and right limiting of the adjusting structure is realized while the front and back movement of the adjusting structure is not influenced; the bottom end face of the main body seat is fixedly connected with an electric telescopic rod through a bolt, the head end of the electric telescopic rod is fixedly connected with the adjusting structure through a bolt, and the main body seat is connected with the forging main body in a welded mode.

In a preferred embodiment, the main body seat includes a second sliding rail and a sliding seat rail seat, two second sliding rails are welded on the main body seat, and the sliding seat rail seat is welded at the center position of the bottom end surface of the main body seat; the feeding cylinder comprises a baffle plate, the feeding cylinder is of a cylindrical tubular structure, and the bottom end face of the feeding cylinder is welded with the baffle plate; and the bottom end face of the baffle is welded on the main body seat, and the thickness of the baffle is the same as that of the part main body.

In a preferred embodiment, the baffle is of an arc-shaped plate-shaped structure matched with the feeding cylinder, and the inner wall of the baffle is aligned with the inner wall of the feeding cylinder.

In a preferred embodiment, the clamping structure comprises two plate-shaped seats, a first sliding rod, a roller, a rectangular plate and a first elastic piece, wherein the two plate-shaped seats are respectively connected in the two second sliding tracks in a sliding manner; two first sliding rods are connected to each plate-shaped seat in a limiting sliding mode, and each first sliding rod is provided with a roller for clamping a part main body; the rectangular plate is connected to the two first sliding rods in a sliding mode and is of a stepped shaft-shaped structure; each first sliding rod is sleeved with a first elastic piece, the roller is in contact with the outer wall of the part main body under the elastic pushing of the first elastic piece, and the part main body is in an elastic clamping state at the moment.

In a preferred embodiment, the adjusting structure comprises a first sliding track, an adjusting rod and adjusting seats, the adjusting rod is rotationally connected in the first sliding track, and the two adjusting seats are slidably connected in the first sliding track; the two adjusting seats are respectively connected with the two rectangular plates in a welding manner, and the two adjusting seats are respectively connected to the left side and the right side of the adjusting rod in a threaded manner; the thread directions of the left end and the right end of the adjusting rod are opposite, and when the adjusting rod is rotated, the two adjusting seats simultaneously move in opposite directions.

In a preferred embodiment, the discharging structure comprises two rectangular seats, and the two rectangular seats are respectively and rotatably connected to the front end surfaces of the two plate-shaped seats through elastic hinges; the rectangle seat is one-way rotating structure, and the preceding terminal surface of rectangle seat contacts with last part main part during the feeding.

In a preferred embodiment, the discharging structure further comprises second sliding rods, cleaning blocks and second elastic pieces, wherein two second sliding rods are connected to each rectangular seat in a sliding manner, and the cleaning blocks are welded at the head ends of the two second sliding rods; the second sliding rod is sleeved with a second elastic piece, and the bottom end face of the cleaning block is in contact with the top end face of the main body seat under the pushing of the elastic force of the second elastic piece.

In a preferred embodiment, the forging body is welded with a cleaning hole, the length of the cleaning hole is equal to the length of the cleaning block, and the width of the cleaning hole is half of the width of the cleaning block.

In a preferred embodiment, when the electric telescopic rod extends out of the feeding hole to the maximum feeding distance, the cleaning block is located at the front position of the cleaning hole.

Compared with the prior art, the forging and feeding device based on material forming processing has the following beneficial effects:

1. the invention improves a feeding structure and an auxiliary structure of the feeding structure, can automatically realize smooth elastic clamping of a part main body when an electric telescopic rod contracts and can automatically realize unloading and automatic cleaning of residues generated by forging when the electric telescopic rod extends, and specifically comprises the following steps: when the electric telescopic rod contracts, the electric telescopic rod pulls the adjusting structure and the clamping structure to move backwards, and a part main body at the lowest position in the feeding cylinder can be clamped through the clamping structure; the second, because of the rear end face of two guide boards is slope column structure to when electric telescopic handle contracts, electric telescopic handle drives clamping structure and adjusts the structure and removes backward, two rear end faces are the guide board of slope form at this moment at first with the contact of part main part, and then can play the guide effect when the tight part main part of slip clamp.

2. When the electric telescopic rod stretches, the electric telescopic rod pushes the adjusting structure and the clamping structure to move forwards to push the part main body to the position below the forging main body, and at the moment, firstly, the rectangular seat is of a one-way rotating structure, and the front end face of the rectangular seat is in contact with the previous part main body during feeding, so that the previous part main body can be automatically unloaded while feeding; secondly, because the second elastic piece is sleeved on the second sliding rod, and the bottom end face of the cleaning block is pushed by the elasticity of the second elastic piece to be in contact with the top end face of the main body seat, the residue can be scraped in the feeding process.

3. The invention improves the structure of the feeding cylinder, and can realize the vertical falling and position limiting of a part main body through improvement, which comprises the following steps: firstly, as the bottom end face of the baffle is welded on the main body seat, the thickness of the baffle is the same as that of the part main body, so that the single part main body can be completely exposed, and the clamping and feeding are convenient; and secondly, the baffle is of an arc-shaped plate structure matched with the feeding cylinder, and the inner wall of the baffle is aligned with the inner wall of the feeding cylinder, so that the part main body is limited on the basis that the part main body does not normally slide downwards.

Drawings

Fig. 1 is a schematic axial view of a forging and feeding device according to the present invention.

FIG. 2 is a schematic axial view of the forging body removed in accordance with the present invention.

Fig. 3 is a schematic top view of the forging feeder according to fig. 2.

Fig. 4 is a schematic axial view of the forging feeder according to the other direction of the material forming process of fig. 2.

Fig. 5 is an enlarged schematic view of fig. 4 at a.

Fig. 6 is an enlarged view of the structure of fig. 4B according to the present invention.

FIG. 7 is an enlarged, isometric view of the clamping and adjustment structures of the present invention.

Fig. 8 is an enlarged view of the structure of fig. 7 at C according to the present invention.

Fig. 9 is an enlarged schematic axial view of the feed cylinder of the present invention.

In the drawings, the corresponding relationship between the component names and the reference numbers is as follows:

1. a main body seat; 101. a second slide rail; 102. a sliding seat rail seat; 2. a feeding cylinder; 201. a baffle plate; 3. a clamping structure; 301. a plate-shaped seat; 302. a first slide bar; 303. a roller; 304. a rectangular plate; 305. a first elastic member; 306. a guide plate; 4. an adjustment structure; 401. a first slide rail; 402. a sliding seat; 403. adjusting a rod; 404. an adjusting seat; 5. an electric telescopic rod; 6. a discharging structure; 601. a rectangular base; 602. a second slide bar; 603. cleaning the block; 604. a second elastic member; 7. a part body; 8. forging and pressing the main body; 801. and (6) cleaning the holes.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

as shown in fig. 1 to 9, a forging and feeding device based on material forming process according to a preferred embodiment of the present invention includes a main body housing 1. A feeding cylinder 2 is welded on the main body seat 1, a part main body 7 is placed in the feeding cylinder 2, and a clamping structure 3 is connected to the main body seat 1 in a sliding mode. The clamping structure 3 is provided with an adjusting structure 4, and the clamping structure 3 is further welded with an unloading structure 6. Referring to fig. 4 and 5, the clamping structure 3 includes two guide plates 306, the two guide plates 306 are provided, and the two guide plates 306 are welded on the rotating seats of the two rollers 303, respectively. And the rear end face of two guide plates 306 is the slope column structure to when electric telescopic handle 5 contracts, electric telescopic handle 5 drives clamping structure 3 and adjusts structure 4 and moves backward, and two rear end faces are the guide plate 306 of slope column at this moment and at first contact with part main part 7, and then can play the guide effect when slip clamp part main part 7. Referring to fig. 2 and 7, the adjusting structure 4 includes a sliding seat 402, the sliding seat 402 is welded on the top end surface of the first sliding rail 401, the sliding seat 402 is slidably connected to the sliding seat rail seat 102, and the sliding seat rail seat 102 constitutes an axial limiting structure of the adjusting structure 4, so that the left and right limiting of the adjusting structure 4 is realized while the front and back movement of the adjusting structure 4 is not influenced; the bottom end face of the main body seat 1 is fixedly connected with an electric telescopic rod 5 through a bolt, the head end of the electric telescopic rod 5 is fixedly connected with an adjusting structure 4 through a bolt, and the main body seat 1 is connected with a forging main body 8 in a welding mode.

Example 2:

referring to fig. 1 and 4, the main body housing 1 includes a second slide rail 101 and a slide housing rail housing 102. Two second sliding rails 101 are welded on the main body seat 1, and a sliding seat rail seat 102 is welded at the center of the bottom end face of the main body seat 1; the feeding cylinder 2 comprises a baffle 201, the feeding cylinder 2 is of a cylindrical tubular structure, and the baffle 201 is welded on the bottom end face of the feeding cylinder 2. And the bottom end face of baffle 201 welds on main part seat 1, and the thickness of baffle 201 is the same with the thickness of part main part 7 to can guarantee that the completion of single part main part 7 exposes, be used for convenient centre gripping feeding.

Referring to fig. 9, the baffle 201 is an arc-shaped plate-shaped structure matched with the feeding cylinder 2, and the inner wall of the baffle 201 is aligned with the inner wall of the feeding cylinder 2, so that the part main body 7 is limited on the basis that the normal downward sliding of the part main body 7 is not influenced.

Example 3:

referring to fig. 4 and 7, the clamping structure 3 includes a plate-shaped seat 301, a first sliding bar 302, a roller 303, a rectangular plate 304, and a first elastic member 305, the plate-shaped seat 301 is provided in two, and the two plate-shaped seats 301 are slidably coupled in the two second sliding rails 101, respectively. Two first sliding rods 302 are connected to each plate-shaped seat 301 in a limiting sliding manner, and each first sliding rod 302 is provided with a roller 303 for clamping the part main body 7. The rectangular plate 304 is slidably connected to the two first sliding rods 302, and the rectangular plate 304 has a stepped shaft-like structure. Each first sliding rod 302 is sleeved with a first elastic piece 305, and the roller 303 is in contact with the outer wall of the part main body 7 under the elastic pushing of the first elastic piece 305, and at the moment, the part main body 7 is in an elastic clamping state, so that the clamping damage phenomenon of the part main body 7 can be avoided.

Referring to fig. 4 and 7, the adjusting structure 4 includes a first sliding rail 401, an adjusting lever 403, and an adjusting seat 404. An adjusting rod 403 is rotatably connected in the first sliding track 401, and two adjusting seats 404 are slidably connected in the first sliding track 401. The two adjusting bases 404 are respectively connected with the two rectangular plates 304 by welding, and the two adjusting bases 404 are respectively connected with the left side and the right side of the adjusting rod 403 by screw threads. The thread directions of the left end and the right end of the adjusting rod 403 are opposite, and when the adjusting rod 403 is rotated, the two adjusting seats 404 simultaneously move in opposite directions, so that synchronous quick adjustment of the two adjusting seats 404 can be realized, further, the rectangular plate 304 is adjusted, the position of the roller 303 is also adjusted, and the clamping of the part main bodies 7 with different sizes can be realized.

Example 4:

referring to fig. 1 and 4, the discharging structure 6 includes two rectangular bases 601, and the two rectangular bases 601 are respectively rotatably connected to the front end surfaces of the two plate-shaped bases 301 through elastic hinges; rectangular seat 601 is one-way rotating-structure, and during the feeding before rectangular seat 601 terminal surface and last part main part 7 contact to can realize the automatic discharge of last part main part 7 in the feeding.

Referring to fig. 4 and 6, the discharging structure 6 further includes second sliding rods 602, cleaning blocks 603 and second elastic members 604, two second sliding rods 602 are slidably connected to each rectangular seat 601, and the cleaning blocks 603 are welded to the head ends of the two second sliding rods 602; the second sliding rod 602 is sleeved with a second elastic member 604, and the bottom end surface of the lower cleaning block 603 is pushed by the elastic force of the second elastic member 604 to contact with the top end surface of the main body seat 1, so that the residue can be scraped off in the feeding process.

Example 5:

referring to fig. 1 and 4, the forging body 8 includes a clearance hole 801, one clearance hole 801 is welded on the forging body 8, the length of the clearance hole 801 is equal to the length of the clearance block 603, and the width of the clearance hole 801 is half of the width of the clearance block 603. When the electric telescopic rod 5 extends out of the feeding position to the maximum feeding distance, the cleaning block 603 is located at the front side position of the cleaning hole 801, so that the residue is cleaned.

When the forging and pressing feeding device based on material forming processing is used, when the electric telescopic rod 5 contracts, the electric telescopic rod 5 pulls the adjusting structure 4 and the clamping structure 3 to move backwards, and a part main body 7 at the lowest part in the feeding cylinder 2 can be clamped through the clamping structure 3. At this time, firstly, the first elastic member 305 is sleeved on each first sliding rod 302, and the roller 303 is pushed by the elasticity of the first elastic member 305 to contact with the outer wall of the part main body 7, and at this time, the part main body 7 is in an elastic clamping state, so that the clamping damage phenomenon of the part main body 7 can be avoided; second, because of the rear end face of two guide boards 306 is slope column structure to when electric telescopic handle 5 contracts, electric telescopic handle 5 drives clamping structure 3 and adjusts structure 4 and moves backward, and two rear end faces are the guide board 306 of slope form at this moment at first with part main part 7 contact, and then can play the guide effect when slip clamp part main part 7. When the electric telescopic rod 5 stretches, the electric telescopic rod 5 pushes the adjusting structure 4 and the clamping structure 3 to move forwards to push the part main body 7 to a position below the forging and pressing main body 8. At this time, firstly, the rectangular base 601 is of a unidirectional rotating structure, and the front end face of the rectangular base 601 is in contact with the previous part main body 7 during feeding, so that automatic discharging of the previous part main body 7 can be realized while feeding; secondly, the second sliding rod 602 is sleeved with the second elastic member 604, and the bottom end surface of the lower cleaning block 603 is pushed by the elastic force of the second elastic member 604 to contact with the top end surface of the main body seat 1, so that the residue can be scraped off in the feeding process.

The embodiments of the present invention have been presented for purposes of illustration and description, and are not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. The utility model provides a forging and pressing feeding device based on material contour machining which characterized in that: comprises a main body seat (1); a feeding cylinder (2) is welded on the main body seat (1), a part main body (7) is placed in the feeding cylinder (2), and the main body seat (1) is also connected with a clamping structure (3) in a sliding manner; an adjusting structure (4) is arranged on the clamping structure (3), and a discharging structure (6) is welded on the clamping structure (3); the clamping structure (3) comprises two guide plates (306), the two guide plates (306) are welded on the rotating seats of the two rollers (303) respectively, and the rear end surfaces of the two guide plates (306) are both of inclined structures; the adjusting structure (4) comprises a sliding seat (402), the sliding seat (402) is welded on the top end face of the first sliding rail (401), the sliding seat (402) is connected to the sliding seat rail seat (102) in a sliding mode, and the sliding seat rail seat (102) forms an axial limiting structure of the adjusting structure (4); the bottom end face of the main body seat (1) is fixedly connected with an electric telescopic rod (5) through a bolt, the head end of the electric telescopic rod (5) is fixedly connected with the adjusting structure (4) through a bolt, and the main body seat (1) is connected with a forging main body (8) in a welding mode;

the main body seat (1) comprises second sliding rails (101) and sliding seat rail seats (102), the two second sliding rails (101) are welded on the main body seat (1), and the sliding seat rail seats (102) are welded at the center of the bottom end face of the main body seat (1); the feeding cylinder (2) comprises a baffle plate (201), the feeding cylinder (2) is of a cylindrical tubular structure, and the baffle plate (201) is welded on the bottom end face of the feeding cylinder (2); the bottom end face of the baffle plate (201) is welded on the main body seat (1), and the thickness of the baffle plate (201) is the same as that of the part main body (7);

the clamping structure (3) comprises two plate-shaped seats (301), a first sliding rod (302), a roller (303), a rectangular plate (304) and a first elastic piece (305), wherein the two plate-shaped seats (301) are respectively connected in the two second sliding tracks (101) in a sliding manner; two first sliding rods (302) are connected to each plate-shaped seat (301) in a limiting sliding mode, and each first sliding rod (302) is provided with a roller (303) used for clamping the part main body (7); the rectangular plate (304) is connected to the two first sliding rods (302) in a sliding mode, and the rectangular plate (304) is of a stepped shaft-shaped structure; each first sliding rod (302) is sleeved with a first elastic piece (305), the roller (303) is in contact with the outer wall of the part main body (7) under the elastic pushing of the first elastic piece (305), and the part main body (7) is in an elastic clamping state;

the discharging structure (6) comprises two rectangular seats (601), and the two rectangular seats (601) are respectively connected to the front end surfaces of the two plate-shaped seats (301) in a rotating mode through elastic hinges; the rectangular base (601) is of a unidirectional rotating structure, and the front end face of the rectangular base (601) is in contact with the upper part main body (7) during feeding; the discharging structure (6) further comprises second sliding rods (602), cleaning blocks (603) and second elastic pieces (604), two second sliding rods (602) are connected onto each rectangular seat (601) in a sliding mode, and the cleaning blocks (603) are welded at the head ends of the two second sliding rods (602); a second elastic piece (604) is sleeved on the second sliding rod (602), and the bottom end surface of the cleaning block (603) is in contact with the top end surface of the main body seat (1) under the pushing of the elasticity of the second elastic piece (604); a cleaning hole (801) is welded on the forging main body (8), the length of the cleaning hole (801) is equal to that of the cleaning block (603), and the width of the cleaning hole (801) is one half of that of the cleaning block (603); when the electric telescopic rod (5) extends out and feeds materials to the maximum feeding distance, the cleaning block (603) is located at the front side position of the cleaning hole (801).

2. A material forming process based forging and feeding apparatus as claimed in claim 1, wherein: the baffle (201) is of an arc-shaped plate-shaped structure matched with the feeding cylinder (2), and the inner wall of the baffle (201) is aligned with the inner wall of the feeding cylinder (2).

3. A material form working based forge feeding apparatus according to claim 2 wherein: the adjusting structure (4) further comprises a first sliding track (401), an adjusting rod (403) and an adjusting seat (404), the adjusting rod (403) is rotatably connected in the first sliding track (401), and the two adjusting seats (404) are slidably connected in the first sliding track (401); the two adjusting seats (404) are respectively connected with the two rectangular plates (304) in a welding mode, and the two adjusting seats (404) are respectively connected to the left side and the right side of the adjusting rod (403) in a threaded mode; the thread directions of the left end and the right end of the adjusting rod (403) are opposite, and when the adjusting rod (403) is rotated, the two adjusting seats (404) simultaneously move in opposite directions.