CN218738105U

CN218738105U - Bed convenient for replacing bed sheet

Info

Publication number: CN218738105U
Application number: CN202222269201.4U
Authority: CN
Inventors: 王吴怡
Original assignee: Lingmi Technology Shanghai Co ltd
Current assignee: Lingmi Technology Shanghai Co ltd
Priority date: 2022-01-28
Filing date: 2022-08-26
Publication date: 2023-03-28
Anticipated expiration: 2032-08-26

Abstract

The utility model belongs to the technical field of the technique of furniture and specifically relates to a bed convenient to change sheet is related to, its base and the bed board of setting in the base top, the base with be equipped with glide machanism between the bed board, bed board and base accessible glide machanism are along base length direction relative displacement, glide machanism includes at least a set of guide assembly and at least two sets of supporting component that are used for forming the support to the bed board and reduce frictional force between bed board and the base along base length direction setting, still be equipped with between bed board and the base and be used for the locking mechanical system with both position relatively fixed. The utility model has the effect of convenient bed sheet replacement.

Description

Bed convenient for replacing bed sheet

Technical Field

The utility model belongs to the technical field of the technique of furniture and specifically relates to a bed convenient to change sheet.

Background

In hotel, hotel or family's accommodation place, when changing the sheet, pull out the bed by the wall earlier, remove the mattress with this to change the sheet, because the quality of bed and mattress is great, it is harder in the pulling in-process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art, and provides a bed convenient for replacing a bed sheet, which has the effect of conveniently replacing the bed sheet.

The above object of the present invention can be achieved by the following technical solutions:

a bed convenient for replacing a bed sheet comprises a base and a bed plate arranged above the base, wherein a sliding mechanism is arranged between the base and the bed plate, the bed plate can be displaced along the length direction of the base through the sliding mechanism, the sliding mechanism comprises at least one group of guide assemblies arranged along the length direction of the base and at least two groups of support assemblies used for supporting the bed plate and reducing the friction force between the bed plate and the base, and a locking mechanism used for relatively fixing the positions of the bed plate and the base is also arranged between the bed plate and the base;

the supporting component comprises a fixed supporting part and a sliding supporting part, the fixed supporting part is arranged on the base, the sliding supporting part is arranged at the position, close to the head part of the bed board, of the bottom surface of the bed board, and when the bed board moves relative to the base, the sliding supporting part moves on the base along with the bed board

Through adopting above-mentioned technical scheme, when the sheet needs to be changed, unblock locking mechanical system removes the bed board through the direction subassembly for bed board and base relative displacement, the user just need not remove whole bed frame alright change the sheet like this, has greatly alleviateed user's working strength, and the supporting component forms the support to the bed board, and alleviate frictional force between bed board and the base, further person of facilitating the use changes the sheet.

The present invention may be further configured in a preferred embodiment as: the guide assembly comprises a sliding block arranged on the bottom surface of the bed board or on the base and a sliding rail arranged on the base or on the bottom surface of the bed board, the sliding rail is arranged along the length direction of the base, and the sliding rail is connected with the sliding block in a sliding fit manner.

Through adopting above-mentioned technical scheme, because the slide rail sets up along base length direction, the bed board alright slide along slide rail length direction, slide guide can be accomplished with the slider cooperation on the one hand to the slide rail, and the another side can be with bed board and base sliding connection.

The present invention may be further configured in a preferred embodiment as: the sliding support part comprises at least two pulleys arranged in pairs.

The present invention in a preferred embodiment can be further configured to: the fixed supporting part is a pulley block, and the pulley block comprises at least two pulleys.

The present invention may be further configured in a preferred embodiment as: the fixed support part is provided with two pulley blocks which are arranged along the length direction of the base.

The present invention may be further configured in a preferred embodiment as: the locking mechanism comprises a lock catch arranged on the bottom surface of the bed board, a lock seat arranged on the base and an unlocking assembly used for driving the lock seat to unlock, and the lock catch and the lock seat are matched to lock the bed board and the base.

By adopting the technical scheme, when the bed sheet needs to be replaced, the unlocking state of the lock catch and the lock seat is firstly released through the unlocking assembly, so that the bed plate can be moved, and the bed sheet can be replaced; after the bed sheet is replaced, the bed plate is reset, and then the bed plate and the base are locked together through the lock catch and the lock seat.

The present invention in a preferred embodiment can be further configured to: and a power component for driving the bed plate to be separated from the base is arranged between the bed plate and the base.

Through adopting above-mentioned technical scheme, power component can further reduce user's intensity of labour, improves work efficiency.

The present invention in a preferred embodiment can be further configured to: the power assembly comprises a spring used for driving the bed board to be separated from the base, the locking mechanism further comprises a base used for installing the spring, and the base is installed on the base.

The present invention may be further configured in a preferred embodiment as: be equipped with the mounting panel between hasp and the bed board, the mounting panel is located base afterbody one side, the hasp is installed and is faced at the mounting panel power component one side.

Through adopting above-mentioned technical scheme, the mounting panel is used for installing parts such as hasp, avoids its direct mount on the bed board, causes the damage to the bed board.

The present invention may be further configured in a preferred embodiment as: the mounting panel is equipped with the bolster towards base one side, the bolster is located mounting panel towards power component one side.

Through adopting above-mentioned technical scheme, the striking that the mounting panel received can be alleviateed to the bed board, increase of service life.

The present invention may be further configured in a preferred embodiment as: be equipped with spacing subassembly between mounting panel and the base, spacing subassembly is including setting up the first locating part on the base and setting up the second locating part on mounting panel or bed board, first locating part and second locating part can form the closure state.

By adopting the technical scheme, the first limiting part and the second limiting part form a locking state, the sliding distance of the bed plate relative to the base is limited on one hand, and the position of the bed plate is fixed on the other hand, so that the inconvenience in use caused by the fact that the bed plate moves back and forth when the bed sheet is replaced is avoided.

The present invention in a preferred embodiment can be further configured to: the bottom surface of the bed board is provided with a limiting strip for limiting the supporting component at the tail part of the base, and the limiting strip is used for preventing the bed board from transversely displacing relative to the base.

Through adopting above-mentioned technical scheme, spacing is restricted the bed board afterbody, avoids colliding the afterbody of bed board, leads to bed board transverse swing.

To sum up, the utility model discloses a following at least one kind of useful technological effect:

1. the bed sheet is convenient for a user to replace, the working strength of the user is reduced, and the working efficiency is improved;

2. the support component can reduce the friction force between the bed plate and the base, prolong the service life of the whole bed and improve the working efficiency;

3. the stability and the safety of the overall structure of the bed can be ensured by arranging the locking mechanism.

Drawings

FIG. 1 is an overall configuration view of the embodiment in normal use;

FIG. 2 is a diagram showing the state of the bed board separated from the base when the bed sheet needs to be replaced in the embodiment;

FIG. 3 is a schematic perspective view of a base in the embodiment;

fig. 4 is a schematic view of the bottom surface of the bed plate in the embodiment;

FIG. 5 is a schematic view illustrating a sliding connection between the slide rail and the slider in the embodiment;

FIG. 6 is a schematic structural view of the base plate and the mounting plate engaged by the guide assembly in the embodiment;

FIG. 7 is a schematic view of a locking mechanism in an embodiment;

FIG. 8 is a schematic structural view of the latch of the embodiment;

FIG. 9 is a schematic view of the back side of the susceptor in the embodiment;

FIG. 10 is a schematic view of a connection structure of the unlocking assembly and the lock base in the embodiment;

FIG. 11 is a schematic view showing an internal structure of a lock housing in the embodiment;

FIG. 12 is a schematic front view of the lock case of the embodiment;

FIG. 13 is a schematic view of the bottom cover separated from the lock base in the embodiment;

FIG. 14 is a schematic view showing the inner structure of the lock holder of the embodiment after separating the bottom cover;

FIG. 15 is a schematic view showing the inner structure of the lock case of the embodiment after the bottom cover is separated;

fig. 16 is a schematic structural diagram of an unlocking assembly in the embodiment.

In the figure, 100, the base; 200. a bed board; 201. a limiting strip; 300. a sliding mechanism; 310. a guide assembly; 311. a slide rail; 312. a slider; 320. a support assembly; 321. a fixed support part; 322. a sliding support part; 400. a locking mechanism; 410. locking; 411. a lock lever; 412. reinforcing ribs; 413. a base plate; 420. A lock seat; 421. a housing; 422. a first notch; 423. a latch bolt; 424. a first torsion spring; 425. a bottom cover; 426. a second notch; 427. a drive plate; 428. a drive plate; 429. a limiting plate; 4210. fixing the rod; 4211. A return tension spring; 4212. a second torsion spring; 4213. a first hinge shaft; 4214. a second hinge shaft; 430. a power assembly; 440. mounting a plate; 450. a buffer member; 460. an unlocking assembly; 461. a hauling rope; 4611. a conduit; 4612. a brake cable; 463. an elastic wrench; 464. a fixing plate; 465. a rotating plate; 466. a third hinge shaft; 467. a third torsion spring; 470. a base; 471. a groove; 500. a limiting component; 501. a first limit piece; 502. a second limiting member.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The embodiment is as follows:

referring to fig. 1-3, for the utility model discloses a bed convenient to change sheet, including base 100 and the bed board 200 of setting above base 100, be equipped with glide machanism 300 between base 100 and the bed board 200, the displacement of bed board 200 accessible glide machanism 300 along base 100 length direction still is equipped with between bed board 200 and the base 100 and is used for the locking mechanical system 400 with both positions relatively fixed.

Referring to fig. 2 and 3, the sliding mechanism 300 includes a guide assembly 310 disposed along a length direction of the base 100 and a support assembly 320 for supporting the deck 200 and reducing a frictional force between the deck 200 and the base 100.

Referring to fig. 2 and 3, the guiding assembly 310 mainly functions to prevent the movement direction of the bed board 200 from deviating when the bed board 200 needs to slide relative to the base 100, and the guiding assembly 310 may be a sliding rail assembly or a pulley assembly.

When the guide assembly 310 adopts a slide rail assembly, the slide rail assembly includes two parts, namely a slide block and a slide rail, one part of the slide block and the slide rail needs to be disposed on the bed board 200, and the other part needs to be disposed on the base 100. The slide block can be arranged on the base 100, and the slide rail is arranged on the bottom surface of the bed board 200; accordingly, when the slide rail is disposed on the bottom surface of the bed board 200, the slide block needs to be disposed on the base 100, which can achieve the guiding function of the guiding assembly 310.

The scheme shown in fig. 3-5 is that the sliding block 312 is disposed on the bottom surface of the bed board 200, the sliding rail 311 is disposed on the base 100, the sliding rail 311 is disposed along the length direction of the base 100, and in order to maintain the uniform and stable stress on the bed board 200 and the base 100 and maintain a good guiding effect, the sliding rail is disposed in the middle of the base 100.

When the guiding assembly 310 employs pulley assemblies, the pulley assemblies may be disposed on the base 100 or on the bottom surface of the bed board 200 or on both the base 100 and the bottom surface of the bed board 200, and when the pulley assemblies are disposed on both the base 100 and the bed board 200, at least two sets of pulley assemblies are required, at least one set is disposed on the base 100, and at least one set is disposed on the bottom surface of the bed board 200.

In summary, the guiding assemblies 310 are at least provided in one group, and the specific number can be set according to the specification of the bed, which structure of guiding assemblies 310 is adopted, and other practical situations.

Referring to fig. 3 and 4, the supporting assembly 320 mainly serves to provide a good support for the deck 200, prevent the deck 200 from being damaged due to uneven stress, and reduce friction between the deck 200 and the base 100 when the deck 200 slides.

The supporting assembly 320 includes a fixing supporting portion 321 and a sliding supporting portion 322, the fixing supporting portion 321 is disposed on the base 100, the sliding supporting portion 322 is disposed at a position near the head of the bedplate 200 at the bottom of the bedplate 200, and when the bedplate 200 is displaced relative to the base 100, the sliding supporting portion 322 moves on the base 100 along with the bedplate 200.

The sliding support 322 includes two pulleys disposed in pairs, and the two pulleys are respectively disposed at positions close to the side edges of the bed board 200, so as to stably support the bed board 200.

The fixing support 321 is a pulley block, two sets of pulley blocks are provided, the pulley blocks are arranged along the length direction of the base 100, and each pulley block comprises two pulleys. In the two groups of pulley blocks, one group is arranged at a position close to the tail part of the base 100, the other group is arranged at the middle part of the base 100, and two pulleys in the pulley blocks are arranged at positions close to the side edges of the base 100.

When the bed board 200 slides on the base 100, the fixing support 321 is fixedly arranged on the base 100, and the sliding support 322 moves on the base 100 along with the bed board 200, so that the sliding support 322 can continuously support the head of the bed board 200, and prevent the bed board 200 from being fractured due to overweight of the mattress.

The guide assembly 310 and the support assembly 320 may be cooperatively disposed according to the above schemes, the scheme shown in fig. 3 and 4 is that the guide assembly 310 employs a sliding rail assembly, and the support assembly 320 employs three sets of pulley assemblies, wherein one set of pulley assembly is disposed at a position of the base 100 near the tail thereof, one set is disposed at a position of the bed board 200 near the head thereof, and the last set is disposed between the two sets of pulley assemblies and disposed on the base 100.

The bottom surface of the bed board 200 is provided with a limiting strip 201 for limiting the fixing and supporting part 321 at the tail part of the base 100, the limiting strip 201 is used for preventing the bed board 200 from transversely moving relative to the base 100, and the two limiting strips 201 are inwards contracted along the head part of the bed board 200 towards the tail part. The limiting strips 201 limit the tail of the bed plate 200, and the collision of the tail of the bed plate 200 is avoided, so that the bed plate 200 can swing transversely.

Referring to fig. 3, 4 and 7, a power assembly 430 for driving the base 100 and the bed board 200 to move relatively is disposed between the base 100 and the bed board 200, and the power assembly 430 is disposed at the bottom of the base 100 or the bed board 200. The power assembly 430 may adopt a structure of an air cylinder, an electric push rod, a spring, and the like.

The scheme that shows in the figure is for adopting the spring mounting on base 100, and locking mechanical system 400 still includes base 470 that is used for installing the spring, and lock seat 420 also installs on base 470, and the spring is equipped with two, and two springs set up respectively in lock seat 420 both sides, are equipped with two recesses 471 on base 470, and two springs are located the recess 471 respectively, and the spring sets up along base 100 length direction, and the spring first half exposes outside the recess 471 to can realize exerting the effort to bed board 200.

The bottom surface of the bed board 200 is provided with a mounting plate 440, and the mounting plate 440 is used for mounting each component, so that damage to the structure of the bed board 200 caused by the fact that each component is directly mounted on the bottom surface of the bed board 200 is avoided. The mounting plate 440 is provided with a buffer 450 towards the base 470, and the buffer 450 reduces the impact on the mounting plate 440 in the using process, and prolongs the service life of the mounting plate 440.

A limiting component 500 for limiting the sliding distance of the bed board 200 relative to the base 100 is arranged between the mounting plate 440 and the base 100. The limiting assembly 500 includes a first limiting member 501 disposed on the base 100 and a second limiting member 502 disposed on the mounting plate 440 or the bed board 200, when the bed sheet needs to be replaced, after the bed board 200 moves to a set position, a locking state is formed between the first limiting member 501 and the second limiting member 502.

To prevent the deck 200 from being separated from the base 100 when the deck 200 is pulled, the stop assembly 500 limits this. The first limiting member 501 and the second limiting member 502 form a locking state, which limits the sliding distance of the bed board 200 relative to the base 100 on one hand, and fixes the position of the bed board 200 on the other hand, thereby preventing the bed board 200 from moving back and forth and causing inconvenience in use when the bed sheet is replaced.

Referring to fig. 1 to 16, the locking mechanism 400 includes a lock catch 410 and a lock seat 420, and further includes an unlocking assembly 460 for driving the lock seat 420 to unlock, wherein the lock catch 410 cooperates with the lock seat 420 to lock the bed board 200 with the base 100.

The lock holder 420 includes a rectangular housing 421, a first notch 422 is formed in the housing 421, a locking tongue 423 is rotatably connected to the housing 421 through a first hinge shaft 4213, a first torsion spring 424 is arranged on the first hinge shaft 4213, one end of the first torsion spring 424 is abutted to the locking tongue 423, the other end of the first torsion spring 424 is abutted to a bottom cover 425 covering the housing 421, and a second notch 426 corresponding to the first notch 422 is formed in the bottom cover 425.

The latch base 420 further includes a driving plate 427 connected to and driven by the unlatching assembly 460, the driving plate 427 is rotatably connected to the housing 421, a driving plate 428 is disposed in the housing 421, and the driving plate 428 is driven by the driving plate 427 to slide back and forth. A fixing rod 4210 is arranged in the shell 421, a return tension spring 4211 is arranged between the fixing rod 4210 and the transmission plate 428, a limiting plate 429 is further arranged in the shell 421, the limiting plate 429 is rotatably arranged in the shell 421 through a second hinge shaft 4214, a second torsion spring 4212 is arranged in the shell 421, the second torsion spring 4212 is arranged in the shell 421 through a rod body, one end of the second torsion spring 4212 abuts against the limiting plate 429 to drive the limiting plate 429 to move towards the direction of the bolt 423, and the other end of the second torsion spring 4212 abuts against the inner wall of the shell 421.

The end of the driving plate 428 opposite to the driving plate 427 is connected to the end of the retainer plate 429, and when the driving plate 427 drives the driving plate 428 to slide, the driving plate 428 drives the retainer plate 429 to rotate around the second hinge axis 4214

The lock 410 can adopt a shaft which is clamped into the lock seat 420 to form locking, and the structure of the lock 410 can be optimized on the basis of the shaft, mainly to realize locking with the lock seat 420; in this embodiment, the latch 410 includes a bottom plate 413 and a lock rod 411 vertically disposed on the bottom plate 413, and a reinforcing rib 412 is disposed between the lock rod 411 and the bottom plate 413 to enhance the structural stability between the lock rod 411 and the base 100.

The unlocking assembly 460 includes a pulling string 461 connected to the latch holder 420, and the latch holder 420 can be unlocked by pulling the pulling string 461. The haulage rope 461 dorsad lock seat 420 one end is connected with elastic wrench 463, elastic wrench 463 include fixed plate 464 and rather than articulated rotor plate 465, rotor plate 465 is connected through third articulated axle 466 with fixed plate 464, the cover is equipped with third torsional spring 467 on the third articulated axle 466, third torsional spring 467 one end is contradicted with fixed plate 464, the other end is contradicted with rotor plate 465, haulage rope 461 one end is passed fixed plate 464 and is connected rotor plate 465. It should be noted that the traction rope 461 is a brake cable 4612, and a spool 4611 is sleeved outside the brake cable 4612.

In the locked state, the locking rod 411 of the lock catch 410 abuts against the locking tongue 423, the locking tongue 423 is forced to rotate around the first hinge shaft 4213, after the locking rod 411 enters the first notch 422 of the housing 421, the locking tongue 423 returns to the original position under the action of the first torsion spring 424 to block the first notch 422, and simultaneously the top end of the limiting plate 429 blocks the end of the locking tongue 423, so that the locking rod 411 is locked.

When the unlocking is needed, the rotating plate 465 is driven, the rotating plate 465 pulls the brake cable 4612, the brake cable 4612 drives the driving plate 427 to rotate, the other end of the driving plate 427 drives the driving plate 428 to slide, the driving plate 428 drives the other end of the limiting plate 429 to be far away from the locking tongue 423, at the moment, the locking rod 411 can push the locking tongue 423 to rotate around the first hinge shaft 4213 until the locking tongue 423 leaves the first notch 422, and the locking tongue 423 is reset under the action of the first torsion spring 424.

It should be noted that only one specific mode of the lock seat, the lock catch and the unlocking assembly is disclosed in the embodiment, in actual use, selection can be performed according to actual conditions, and only the functions of locking and unlocking need to be realized.

The implementation principle of the embodiment is as follows: when the bed sheet needs to be replaced, the lock catch 410 and the lock seat 420 are unlocked by pulling the pulling rope 461, the power assembly 430 pushes the bed sheet 200 to be separated from the base 100, and the moving direction of the bed sheet 200 cannot deviate under the combined action of the guide assembly 310 and the support assembly 320, and in addition, the guide assembly 310 and the support assembly 320 adopt a sliding rail assembly and a pulley assembly, so that the friction force received by the bed sheet 200 when moving is reduced, a user can conveniently pull the bed sheet 200, and the user can replace the bed sheet.

When the bed sheet is replaced, the bed sheet 200 is reset by pushing the bed sheet 200 back, and the lock catch 410 and the lock seat 420 form locking, so that the positions of the bed sheet 200 and the base 100 are relatively fixed, and the bed sheet 200 and the base 100 are prevented from moving relatively when a user uses the bed sheet, so that the overall safety is ensured.

The embodiment of this specific implementation mode is the preferred embodiment of the present invention, not limit according to this the utility model discloses a protection scope, so: all equivalent changes made according to the structure, shape and principle of the utility model are covered within the protection scope of the utility model.

Claims

1. The utility model provides a bedding convenient to change sheet, includes base (100) and bed board (200) of setting in base (100) top, its characterized in that: a sliding mechanism (300) is arranged between the base (100) and the bed plate (200), the bed plate (200) can be displaced along the length direction of the base (100) through the sliding mechanism (300), the sliding mechanism (300) comprises at least one group of guide assemblies (310) arranged along the length direction of the base (100) and at least two groups of support assemblies (320) used for supporting the bed plate (200) and reducing the friction force between the bed plate (200) and the base (100), and a locking mechanism (400) used for relatively fixing the positions of the bed plate (200) and the base (100) is further arranged between the bed plate (200) and the base (100);

support assembly (320) include fixed support portion (321) and slide supporting portion (322), fixed support portion (321) set up on base (100), slide supporting portion (322) set up in the position that bed board (200) bottom surface is close to its head, when relative base (100) displacement of bed board (200), slide supporting portion (322) move on base (100) along with bed board (200).

2. The bedding set convenient for changing bed sheets as claimed in claim 1, wherein: the guide assembly (310) comprises a sliding block arranged on the bottom surface of the bed board (200) or on the base (100) and a sliding rail arranged on the base (100) or on the bottom surface of the bed board (200), the sliding rail is arranged along the length direction of the base (100), and the sliding rail is connected with the sliding block in a sliding fit manner.

3. A bed set convenient for changing sheets according to any one of claims 1-2, wherein: the sliding support (322) comprises at least two pulleys arranged in pairs.

4. The bedding set convenient for changing bed sheets as claimed in claim 3, wherein: the fixed supporting part (321) is a pulley block, and the pulley block comprises at least two pulleys.

5. The bed tool convenient for changing the bed sheet as claimed in claim 4, wherein: the fixed supporting part (321) is provided with two pulley blocks which are arranged along the length direction of the base (100).

6. The bedding set convenient for changing bed sheets as claimed in claim 5, wherein: the locking mechanism (400) comprises a lock catch (410) arranged on the bottom surface of the bed plate (200) and a lock seat (420) arranged on the base (100), and further comprises an unlocking assembly (460) used for driving the lock seat (420) to unlock, and the lock catch (410) and the lock seat (420) are matched to form locking between the bed plate (200) and the base (100).

7. The bedding set convenient for changing bed sheets as claimed in claim 6, wherein: and a power component (430) for driving the bed plate (200) to be separated from the base (100) is arranged between the bed plate (200) and the base (100).

8. The bedding set convenient for changing bed sheets as claimed in claim 7, wherein: the power assembly (430) comprises a spring for driving the bed plate (200) to be separated from the base (100), the locking mechanism (400) further comprises a base (470) for mounting the spring, and the base (470) is mounted on the base (100).

9. The bedding set convenient for changing bed sheets as claimed in claim 8, wherein: be equipped with between hasp (410) and bed board (200) mounting panel (440), mounting panel (440) are located base (470) towards base (100) afterbody one side, hasp (410) are installed and are faced in mounting panel (440) power component (430) one side.

10. The bedding set convenient for changing bed sheets as claimed in claim 9, wherein: the side, facing the base (470), of the mounting plate (440) is provided with a buffer (450), and the buffer (450) is located on the side, facing the power assembly (430), of the mounting plate (440).

11. The bedding set facilitating sheet change of claim 10, wherein: be equipped with spacing subassembly (500) between mounting panel (440) and base (100), spacing subassembly (500) are including setting up first locating part (501) on base (100) and setting up second locating part (502) on mounting panel (440) or bed board (200), first locating part (501) and second locating part (502) can form locking state when being close to.

12. The bedding set convenient for changing bed sheets as claimed in claim 5, wherein: the limiting device is characterized in that a limiting strip (201) used for limiting a tail fixing and supporting part (321) of the base (100) is arranged on the bottom surface of the bed plate (200), and the limiting strip (201) is used for limiting the transverse displacement of the bed plate (200) relative to the base (100).