CN223718714U

CN223718714U - A welding fixture for a bed frame with longitudinal beams

Info

Publication number: CN223718714U
Application number: CN202520066439.8U
Authority: CN
Inventors: 穆德敏; 陶林; 李海龙; 程亮; 黄小列; 苗斯琪; 白雪松; 姜兴权; 安俊枫; 李忠丽
Original assignee: Shenyang Institute of Technology
Current assignee: Shenyang Institute of Technology
Priority date: 2025-01-13
Filing date: 2025-01-13
Publication date: 2025-12-26
Anticipated expiration: 2035-01-13

Abstract

The utility model relates to a welding fixture for a bed frame with longitudinal beams, wherein a longitudinal beam positioning mechanism comprises a longitudinal beam pressing assembly and a longitudinal beam tightening assembly, the longitudinal beam pressing assembly is provided with a longitudinal beam positioning block with lifting degrees and rotation degrees, the longitudinal beam tightening assembly comprises a tightening seat, a tightening installation seat, tightening blocks and lifting blocks, the lower end of the tightening installation seat is arranged on a positioning frame, the upper end of the tightening installation seat is provided with a placing groove for placing two longitudinal beams, the tightening seat is arranged in the middle of the placing groove and between the two longitudinal beams, two sides of the tightening seat are provided with telescopic tightening blocks, lifting blocks are arranged in the tightening seat, lifting inclined planes are arranged on the lower sides of the lifting blocks, tightening inclined planes matched with the lifting inclined planes are arranged on the inner sides of the tightening blocks, tension spring connecting rods are arranged on the tightening blocks on two sides of the tightening seat, and tension spring connecting rods on the same side are connected through tension springs. The utility model can ensure that the frame, the longitudinal beam, the cross beam and the middle beam assembly forming the bedstead are positioned accurately during welding, thereby ensuring the welding quality.

Description

Welding fixture for bed frame with longitudinal beam

Technical Field

The utility model relates to the field of welding tools, in particular to a welding fixture for a bedstead with a longitudinal beam.

Background

With the development of the technology, some bed frame welding positioning tools appear in the prior art, for example, CN220659752U discloses a bed frame welding positioning tool, which includes a base plate and a plurality of positioning components, the base plate is provided with a plurality of installation positions arranged along the length direction, and the plurality of positioning components are respectively installed at each installation position and can be detached relative to the installation positions. But the locating component of this frock mainly comprises positioning seat and mounting panel, and when assembling locating component, the last connecting hole of mounting panel corresponds with the lower connecting hole on the bottom plate, then penetrates locating pin or bolt and can fix a position locating component on the installation position that corresponds and to the bed frame, when needing to adjust the size, only need to lift locating pin or bolt off and move locating component's position can.

CN210849011U patent discloses a flexible welding location frock for medical bed frame welding, it includes the base, and left side roof beam location tight assembly and right side roof beam location tight assembly are installed respectively to the left and right sides of base, and first intermediate beam location centre gripping assembly and back tip location hold-down assembly are installed to the rear end of base, and second intermediate beam location centre gripping assembly is installed to the front end of base, and left side roof beam, right side roof beam, first intermediate beam, second intermediate beam and back end roof beam to medical bed frame need press from both sides tight location when this frock uses.

However, some special-purpose frames, such as a pension frame, have structures including stringers along the length of the frame in addition to the frame and middle cross members, and the spacing between two adjacent stringers is often required, which requires further improvement of the existing welding fixture for the frame. For example, CN221159062U discloses a welding positioning device, it has set up longeron stop gear, and the longeron stop gear of the device includes the support frame, and both ends are provided with the longeron fixed subassembly that is used for spacing to longeron centre gripping on the support frame, be provided with the spacing clamping assembly of crossbeam centre gripping between the longeron fixed subassembly, the longeron fixed subassembly is including setting up screw rod on the support frame, be connected with spacing seat on the screw rod, the notch has been seted up to spacing seat opposite face, and this notch upper side sliding connection has the guide pillar, the guide pillar lower extreme is fixed with first clamp plate, the guide pillar external diameter is located first clamp plate upside cover is equipped with the spring, the clamping assembly is including fixing the backup pad of support frame both sides, sliding connection has the traveller in the backup pad, the traveller opposite end is fixed with splint, be located on the traveller splint with the cover is equipped with the spring between the backup pad, this longeron stop gear structure is complicated relatively.

Disclosure of utility model

The utility model aims to provide a welding fixture for a bedstead with a longitudinal beam, which can ensure that the frame, the longitudinal beam, the cross beam and the middle beam component forming the bedstead are positioned accurately during welding, thereby ensuring the welding quality.

The aim of the utility model is realized by the following technical scheme:

A welded fastening frock for taking longeron bedstead, include the locating rack and locate frame locating component, crossbeam locating component, intermediate beam locating component and longeron locating mechanism on the locating rack, wherein longeron locating mechanism includes longeron hold-down subassembly and longeron and props tight subassembly, longeron hold-down subassembly is equipped with the longeron locating piece that has lift and rotation degree of freedom, longeron props tight subassembly including propping tight seat, propping tight mount pad, propping tight piece and lifting block, wherein prop tight mount pad lower extreme and locate the locating rack is last, the upper end is equipped with the standing groove of placing two longerons, props tight seat to locate the standing groove middle part just is located between two longerons, prop tight seat both sides and be equipped with telescopic and prop tight piece, prop tight seat inside to the lift piece downside is equipped with the lift inclined plane, prop tight piece inboard be equipped with the extension spring connecting rod of lift inclined plane complex and prop tight piece both sides and all be equipped with the extension spring connecting rod on propping tight piece of tight seat both sides, and the extension spring of homonymy passes through the connection.

The supporting installation seat is provided with a supporting cylinder, and the lifting block is driven to lift by the supporting cylinder.

The longitudinal beam pressing assembly comprises a pressing installation seat and a longitudinal beam positioning driving device, wherein the pressing installation seat is installed on the positioning frame, the longitudinal beam positioning driving device is arranged on the pressing installation seat, and the longitudinal beam positioning block is arranged on the longitudinal beam positioning driving device.

The frame positioning assembly and the beam positioning assembly are identical in structure and comprise positioning installation seats arranged on the positioning frames, press block driving devices, limiting blocks and jacking cylinders are arranged on the positioning installation seats, and positioning press blocks with lifting degrees of freedom and rotating degrees of freedom are arranged on the press block driving devices.

The middle beam positioning assembly comprises a middle beam positioning seat arranged on the positioning frame, a first positioning cylinder, a second positioning cylinder, a first limiting seat, a second limiting seat, a first compression driving device and a second compression driving device are arranged on the middle beam positioning seat, a first positioning block with lifting and rotating degrees of freedom is arranged on the first compression driving device, and a second positioning block with lifting and rotating degrees of freedom is arranged on the second compression driving device.

The middle beam assembly in the middle of the bedstead comprises a first middle beam and a second middle beam, wherein the first middle beam is matched with the first positioning cylinder and the first limiting seat to limit horizontal displacement, the first positioning block is pressed to limit vertical displacement, the second middle beam is matched with the second positioning cylinder and the second limiting seat to limit horizontal displacement, and the second positioning block is pressed to limit vertical displacement.

The locating rack passes through tilting mechanism drive rotation, tilting mechanism includes the base and locates the upset supporting seat at base both ends is equipped with the upset motor in one of them upset supporting seat, is equipped with the upset bearing frame in another upset supporting seat, the locating rack both ends are equipped with the upset and link the board, just the upset of locating rack one end link the board with the power shaft of upset motor is connected, be equipped with the pivot on the upset that the other end links the board install in the upset bearing frame.

The bedstead to be welded comprises a frame, wherein an intermediate beam assembly is arranged in the middle of the frame, two groups of longitudinal beams are arranged on two sides of the front part of the frame, a cross beam is arranged in the rear part of the frame, the frame is fixed through the frame positioning assembly, the cross beam is fixed through the cross beam positioning assembly, the intermediate beam assembly is fixed through the intermediate beam positioning assembly, and the longitudinal beams are positioned through the longitudinal beam positioning mechanism.

The utility model has the advantages and positive effects that:

1. The longitudinal beam positioning mechanism is provided with the longitudinal beam compression assembly and the longitudinal beam tightening assembly, wherein the two longitudinal beams are firstly placed in the placing grooves at the upper ends of the corresponding side longitudinal beam tightening assemblies to realize preliminary positioning, then the lifting blocks in the longitudinal beam tightening assemblies descend and drive the tightening blocks at the two sides of the tightening seat to outwards move to respectively prop against the longitudinal beams at the corresponding sides through the cooperation of the lifting inclined surfaces at the lower ends and the tightening inclined surfaces to finish horizontal positioning.

2. The frame positioning assembly and the beam positioning assembly have the same structure, so that the number of positioning assembly modules can be reduced, and the cost is further reduced.

3. The positioning frame can be driven to turn over through the turning mechanism to meet the multi-angle welding requirement of the welding robot.

Drawings

Figure 1 is a schematic view of the structure of the present utility model,

Figure 2 is an enlarged view at a in figure 1,

Figure 3 is a top view of the frame positioning assembly of figure 2,

Figure 4 is an enlarged view at B in figure 1,

Figure 5 is a top view of the center sill positioning assembly of figure 4,

Figure 6 is an enlarged view at C in figure 1,

Figure 7 is a top view of the stringer bracing assembly of figure 6,

Figure 8 is a view H-H of figure 7,

Figure 9 is a cross-sectional view of the utility model of figure 1,

Fig. 10 is a schematic view of the bed frame in fig. 1.

Wherein 1 is a bedstead, 101 is a frame, 102 is a longitudinal beam, 103 is a middle beam component, 1031 is a first middle beam, 1032 is a second middle beam, 104 is a cross beam, 2 is a frame positioning component, 201 is a pressing cylinder, 202 is a positioning press block, 203 is a press block driving device, 204 is a positioning mounting seat, 205 is a positioning block, 3 is a cross beam positioning component, 4 is a middle beam positioning component, 401 is a first positioning block, 402 is a second positioning cylinder, 403 is a first pressing driving device, 404 is a first positioning cylinder, 405 is a middle beam positioning seat, 406 is a second pressing driving device, 407 is a second positioning block, 5 is a longitudinal beam positioning mechanism, 501 is a longitudinal beam pressing component, 5011 is a longitudinal beam positioning block, 5012 is a longitudinal beam positioning driving device, 5013 is a pressing mounting seat, 502 is a longitudinal beam pressing component, 5021 is a pressing seat, 5022 is a pressing cylinder, 5023 is a pressing mounting seat, 31 is a placing groove, 4 is a pressing block, 50241 is a pressing inclined surface, 5 is a tension spring, 6 is a lifting block, 407 is a motor, 407 is a turnover seat, 602 is a turnover seat, 6011 is a turnover seat, and 6011 is a turnover seat.

Detailed Description

The utility model is described in further detail below with reference to the accompanying drawings.

As shown in fig. 1 to 10, the utility model comprises a positioning frame 601, a frame positioning assembly 2, a cross beam positioning assembly 3, a middle beam positioning assembly 4 and a longitudinal beam positioning mechanism 5 which are arranged on the positioning frame 601, wherein as shown in fig. 10, the utility model is directed to a bedstead 1 which comprises a frame 101, the middle part of the frame 101 is provided with a middle beam assembly 103, two groups of longitudinal beams 102 are arranged on two sides of the front part of the frame 101, the distance between the two longitudinal beams 102 in each group is equal and the design requirement needs to be met, and a cross beam 104 is arranged in the rear part of the frame 101. In operation of the utility model, the frame 101 is fixed by the frame positioning assembly 2, the cross beam 104 is fixed by the cross beam positioning assembly 3, the intermediate beam assembly 103 is fixed by the intermediate beam positioning assembly 4, and the longitudinal beam 102 is positioned by the longitudinal beam positioning mechanism 5.

As shown in fig. 6-8, in this embodiment, the longitudinal beam positioning mechanism 5 includes a longitudinal beam compressing assembly 501 and a longitudinal beam tightening assembly 502, wherein the longitudinal beam compressing assembly 501 is provided with a longitudinal beam positioning block 5011 having lifting degrees and rotation degrees, the longitudinal beam tightening assembly 502 includes a tightening seat 5021, a tightening installation seat 5023, a tightening block 5024 and a lifting block 5027, wherein the lower end of the tightening installation seat 5023 is arranged on the positioning frame 601, a placing groove 50231 for placing two longitudinal beams 102 is arranged at the upper end of the positioning frame 601, the tightening seat 5021 is arranged in the middle of the placing groove 50231 and between the two longitudinal beams 102, telescopic tightening blocks 5024 are arranged on two sides of the tightening seat 5021, lifting blocks 5027 are arranged inside the tightening seat 5021, lifting inclined planes are arranged on the lower sides of the lifting blocks 5027, tension springs 50241 matched with the lifting inclined planes are arranged on the inner sides of the tightening blocks 5024, as shown in fig. 7, and tension springs 5025 are arranged on the two sides of the tightening seat 5021 and connected with tension springs 5025 through the tension springs 5026. When the utility model works, the two stringers 102 are firstly placed in the placing groove 50231 at the upper end of the corresponding side stringer tightening assembly 502 to realize preliminary positioning, then as shown in fig. 8, the lifting blocks 5027 are lowered and drive the tightening blocks 5024 at the two sides of the tightening seat 5021 to move outwards to respectively prop against the stringers 102 at the corresponding side through the cooperation of the lifting inclined surface at the lower end and the tightening inclined surface 50241 to finish positioning in the horizontal direction, the stringer positioning blocks 5011 in the stringer pressing assembly 501 are lowered to tightly prop against the stringers 102 at the corresponding side to finish positioning in the vertical direction, after the processing is finished, the stringer positioning blocks 5011 are raised and rotated by 90 degrees to ensure that the bedstead 1 can be taken out, and the lifting blocks 5027 are raised to enable the tightening blocks 5024 at the two sides to move inwards under the action of the tension springs 5026 to not prop up the stringers 102.

As shown in fig. 6-8, in this embodiment, a tightening cylinder 5022 is disposed on the tightening mounting base 5023, and the lifting block 5027 is driven to lift by the tightening cylinder 5022.

As shown in fig. 6-8, in this embodiment, the longitudinal beam compressing assembly 501 includes a compressing installation seat 5013 and a longitudinal beam positioning driving device 5012, wherein the compressing installation seat 5013 is installed on the positioning frame 601, the longitudinal beam positioning driving device 5012 is disposed on the compressing installation seat 5013, and the longitudinal beam positioning block 5011 is disposed on the longitudinal beam positioning driving device 5012. In this embodiment, the longitudinal beam positioning driving device 5012 includes a cylinder and a motor which are sequentially connected, and the longitudinal beam positioning block 5011 is mounted on the motor, the motor is driven by the cylinder to lift together with the longitudinal beam positioning block 5011, and the longitudinal beam positioning block 5011 is driven by the motor to rotate to ensure that the bed frame 1 can be put in or taken out.

As shown in fig. 1 to 3, in this embodiment, the frame positioning assembly 2 and the beam positioning assembly 3 have the same structure, and each of them includes a positioning mounting seat 204 disposed on the positioning frame 601, and the positioning mounting seat 204 is provided with a press block driving device 203, a limiting block 205 and a tightening cylinder 201, and the press block driving device 203 is provided with a positioning press block 202 having lifting and rotating degrees of freedom. When the utility model works, the limiting block 205 and the jacking cylinder 201 are matched with the corresponding side beams or the corresponding cross beams 104 of the fixed frame 101 along the horizontal direction, and the positioning pressing block 202 is pressed against the corresponding side beams or the corresponding cross beams 104 of the fixed frame 101 along the vertical direction. In this embodiment, the press block driving device 203 and the longitudinal beam positioning driving device 5012 have the same structure and each include a motor and a cylinder, so that the positioning press block 202 can rotate by 90 ° to ensure that the bed frame 1 is put in and taken out.

In addition, as shown in fig. 1-2, the utility model can also set only the frame pressing assembly 7 on the outer side of any side beam of the frame 101 to realize auxiliary pressing according to the requirement, wherein the frame pressing assembly 7 only comprises the pressing block driving device 203 and the positioning pressing block 202.

As shown in fig. 4 to 5, in this embodiment, the middle beam assembly 103 of the bed frame 1 includes a first middle beam 1031 and a second middle beam 1032, the middle beam positioning assembly 4 includes a middle beam positioning seat 405 disposed on the positioning frame 601, and a first positioning cylinder 404, a second positioning cylinder 402, a first limiting seat, a second limiting seat, a first compression driving device 403 and a second compression driving device 406 are disposed on the middle beam positioning seat 405, wherein the first compression driving device 403 has a first positioning block 401 with lifting and rotating degrees of freedom, and the second compression driving device 406 has a second positioning block 407 with lifting and rotating degrees of freedom. When the utility model works, the first middle beam 1031 is matched with the first positioning cylinder 404 to limit the horizontal displacement, the first positioning block 401 is used for compressing and limiting the vertical displacement, the second middle beam 1032 is matched with the second positioning cylinder 402 and the second positioning block 407 to limit the horizontal displacement, the second positioning block 407 is used for compressing and limiting the vertical displacement, the first compression driving device 403, the second compression driving device 406 and the longitudinal beam positioning driving device 5012 have the same structure, and the first middle beam 1031 and the second middle beam include a motor and a cylinder, so that the first positioning block 401 and the second positioning block 407 can rotate by 90 degrees to ensure that the bedstead 1 is put in or taken out.

The positioning mounting seat 204, the middle beam positioning seat 405, the compression mounting seat 5013 and the tightening mounting seat 5023 may be fixed structures, or may be movable and adjustable sliding structures according to actual needs, for example, the lower ends of the above-mentioned respective seats are provided with sliding grooves and corresponding beam bodies on the positioning frame 601 are in sliding fit, and meanwhile, the respective seats are provided with locking bolts or other locking elements to ensure locking and positioning, or may also adopt sliding connection structures in CN210849011U, which is a well-known technology in the art.

As shown in fig. 1 and 9, in this embodiment, the positioning frame 601 is driven to rotate by the turnover mechanism 6, the turnover mechanism 6 includes a base 605 and turnover supporting seats 604 disposed at two ends of the base 605, one of the turnover supporting seats 604 is provided with a turnover motor 602, the other turnover supporting seat 604 is provided with a turnover bearing seat 603, two ends of the positioning frame 601 are provided with turnover connecting plates 6011, the turnover connecting plates 6011 at one end of the positioning frame 601 are connected with a power shaft of the turnover motor 602, and a rotation shaft is disposed on the turnover connecting plates 6011 at the other end of the positioning frame 601 and is mounted in the turnover bearing seat 603.

The working principle of the utility model is as follows:

When the utility model works, the frame 101, the longitudinal beam 102, the middle beam assembly 103 and the cross beam 104 which form the bedstead 1 are placed at the corresponding positions on the positioning frame 601 by a mechanical arm or manually, then the frame positioning assembly 2, the cross beam positioning assembly 3, the middle beam positioning assembly 4 and the longitudinal beam positioning mechanism 5 are started to respectively finish the positioning of the parts in the horizontal direction and the vertical direction, after the positioning is finished, the welding mechanical arm is started to weld the parts according to the set degree, after the welding is finished, the positioning blocks in the positioning assemblies are lifted firstly, and then rotated for 90 degrees to avoid blocking the bedstead 1, and then the mechanical arm or manually takes down the bedstead 1 which is finished in the welding.

As shown in fig. 10, two sides of the front part of the bed frame 1 are provided with longitudinal beams 102, and the positions of each group of longitudinal beams 102 and the distance between the two longitudinal beams 102 in each group are required, so that the longitudinal beam positioning mechanism 5 is provided with a longitudinal beam compacting assembly 501 and a longitudinal beam tightening assembly 502, when the utility model works, the two longitudinal beams 102 are firstly placed in a placing groove 50231 at the upper end of the corresponding side longitudinal beam tightening assembly 502 to realize preliminary positioning, then as shown in fig. 8, the lifting block 5027 descends and drives the tightening blocks 5024 at the two sides of the tightening seat 5021 to outwards move to respectively prop against the longitudinal beams 102 at the corresponding side through the cooperation of the lifting inclined surface at the lower end and the tightening inclined surface 50241 to finish positioning in the horizontal direction, and the longitudinal beam positioning block 5011 in the longitudinal beam compacting assembly 501 descends to tightly press the longitudinal beam 102 at the corresponding side to finish positioning in the vertical direction, so that the positioning of each group of longitudinal beams 102 can be fully ensured to be accurate, and the accurate subsequent welding position is ensured.

Claims

1. A welded fastening tool for a bed frame with longitudinal beams is characterized by comprising a positioning frame (601) and a frame positioning assembly (2), a beam positioning assembly (3), a middle beam positioning assembly (4) and a longitudinal beam positioning mechanism (5) which are arranged on the positioning frame (601), wherein the longitudinal beam positioning mechanism (5) comprises a longitudinal beam pressing assembly (501) and a longitudinal beam tightening assembly (502), the longitudinal beam pressing assembly (501) is provided with a longitudinal beam positioning block (5011) with lifting and rotating degrees of freedom, the longitudinal beam tightening assembly (502) comprises a tightening seat (5021), a tightening installation seat (5023), a tightening block (5024) and a lifting block (5027), the lower end of the tightening installation seat (5023) is arranged on the positioning frame (601), the upper end of the tightening installation seat is provided with a placing groove (50231) for placing two longitudinal beams (102), the tightening seat (5021) is arranged in the middle of the placing groove (50231) and between the two longitudinal beams (102), two sides of the tightening seat (501) are provided with telescopic tightening blocks (4), the inside of the tightening seat (5021) is provided with a tightening block (5027) and the inside of the lifting block (5027) is provided with a lifting inclined plane (5025), and the tension spring connecting rods (5025) on the same side are connected through tension springs (5026).

2. The welding fixture for the bed frame with the longitudinal beam of claim 1, wherein the tightening installation seat (5023) is provided with a tightening cylinder (5022), and the lifting block (5027) is driven to lift through the tightening cylinder (5022).

3. The welding fixture for a bed frame with a longitudinal beam of claim 1, wherein the longitudinal beam pressing assembly (501) comprises a pressing mounting seat (5013) and a longitudinal beam positioning driving device (5012), wherein the pressing mounting seat (5013) is mounted on the positioning frame (601), the longitudinal beam positioning driving device (5012) is arranged on the pressing mounting seat (5013), and the longitudinal beam positioning block (5011) is arranged on the longitudinal beam positioning driving device (5012).

4. The welding fixture for the bed frame with the longitudinal beam of claim 1, wherein the frame positioning assembly (2) and the cross beam positioning assembly (3) are identical in structure and comprise positioning installation seats (204) arranged on the positioning frame (601), a pressing block driving device (203), a limiting block (205) and a jacking cylinder (201) are arranged on the positioning installation seats (204), and a positioning pressing block (202) with lifting and rotating degrees of freedom is arranged on the pressing block driving device (203).

5. The welding fixture for a bed frame with longitudinal beams according to claim 1, wherein the middle beam positioning assembly (4) comprises a middle beam positioning seat (405) arranged on the positioning frame (601), a first positioning cylinder (404), a second positioning cylinder (402), a first limiting seat, a second limiting seat, a first compression driving device (403) and a second compression driving device (406) are arranged on the middle beam positioning seat (405), a first positioning block (401) with lifting and rotating degrees of freedom is arranged on the first compression driving device (403), and a second positioning block (407) with lifting and rotating degrees of freedom is arranged on the second compression driving device (406).

6. The welding fixture for a frame with stringers according to claim 5, wherein the middle beam assembly (103) of the middle portion of the frame (1) comprises a first middle beam (1031) and a second middle beam (1032), and the first middle beam (1031) is compressed and defined by the first positioning cylinder (404) and the first limiting seat to displace in a horizontal direction, the first positioning block (401) is compressed and defined by the first positioning block (401), and the second middle beam (1032) is compressed and defined by the second positioning cylinder (402) and the second limiting seat to displace in a horizontal direction, and the second positioning block (407) is compressed and defined by the second positioning block to displace in a vertical direction.

7. The welding fixture for the bed frame with the longitudinal beams according to claim 1, wherein the positioning frame (601) is driven to rotate through a turnover mechanism (6), the turnover mechanism (6) comprises a base (605) and turnover supporting seats (604) arranged at two ends of the base (605), a turnover motor (602) is arranged in one turnover supporting seat (604), a turnover bearing seat (603) is arranged in the other turnover supporting seat (604), turnover connecting plates (6011) are arranged at two ends of the positioning frame (601), the turnover connecting plates (6011) at one end of the positioning frame (601) are connected with a power shaft of the turnover motor (602), and a rotating shaft is arranged on the turnover connecting plates (6011) at the other end of the positioning frame (601) and is arranged in the turnover bearing seat (603).

8. The welding fixture for a bed frame with longitudinal beams according to claim 1, wherein the bed frame (1) to be welded comprises a frame (101), an intermediate beam assembly (103) is arranged in the middle of the frame (101), two groups of longitudinal beams (102) are arranged on two sides of the front part of the frame (101), a transverse beam (104) is arranged in the rear part of the frame (101), the frame (101) is fixed through the frame positioning assembly (2), the transverse beam (104) is fixed through the transverse beam positioning assembly (3), the intermediate beam assembly (103) is fixed through the intermediate beam positioning assembly (4), and the longitudinal beams (102) are positioned through the longitudinal beam positioning mechanism (5).