CN220937429U - Folding bed - Google Patents

Abstract

The utility model provides a folding bed, including bed surface and bedstead, the bedstead includes two bedstead pipes and sets up at least one collapsible four-corner support frame of two bedstead pipe lower extreme, collapsible four-corner support frame includes a collapsible rectangular frame and four upper prop and four lower prop, collapsible rectangular frame includes two longitudinal bars, two horizontal poles and four connecting blocks, two longitudinal bars are parallel to locate the below of two bedstead pipes respectively, two horizontal poles are located perpendicularly respectively between the both ends of two longitudinal bars, four connecting blocks link together two longitudinal bars and the adjacent tip of two horizontal poles respectively, the lower extreme of four upper prop is detachably pegged graft respectively in the upper portion of four connecting blocks, two a set of respectively with a bedstead pipe detachably in the upper end of four upper prop is connected, the upper end of four lower prop is detachably pegged graft respectively in the lower part of four connecting blocks, the lower extreme of four lower prop is used for contacting with ground respectively. The folding bed has the advantages of high structural strength, good stability, small volume after folding, portability and the like.

Description

Folding bed

Technical Field

The utility model relates to the technical field of articles for daily use, in particular to a folding bed.

Background

Chinese patent CN202222965035.1 discloses a folding bed, which comprises a foldable bed surface cloth pad, a detachable folding support tube and a foldable support, wherein the support comprises a main shaft assembly with a supporting function and symmetrically distributed support assemblies, the main shaft assembly comprises a first cross bar fixedly connected by screws, a connecting seat and a second cross bar rotatably connected with the connecting seat by a rotating shaft, the support assemblies comprise a support with a connecting function, a first support leg and a second support leg with a supporting stabilizing function, limit sleeves with integrated structures are symmetrically arranged on the support, one ends of the first support legs are inserted into the support, one ends of the second support legs are inserted into the limit sleeves, and the ends of the first support legs far away from the support are provided with support heads.

In such a folding bed, since the support lacks a supporting function in the length direction (i.e., longitudinal direction) of the folding stay, the folding bed has a low overall structural strength, is not strong enough after being unfolded on the ground, and is easily collapsed, that is, the folding bed has to be improved in stability in use.

Disclosure of utility model

The utility model aims to overcome the defects of the prior art and provide the folding bed which has high structural strength and good firmness and is supported stably during use.

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

The folding bed comprises a bed surface and a bed frame, wherein the bed frame comprises two bed frame pipes which are arranged in parallel at intervals along the horizontal direction, the bed surface is made of flexible foldable materials, and two sides of the bed surface are respectively detachably connected with the two bed frame pipes; the folding rectangular frame comprises two longitudinal rods, two transverse rods and four connecting blocks, wherein the two longitudinal rods are respectively arranged below the two bedstead pipes in parallel, the two transverse rods are respectively and vertically arranged between two ends of the two longitudinal rods, the four connecting blocks are respectively used for connecting adjacent ends of the two longitudinal rods and the two transverse rods together, the lower ends of the four upper supporting rods are respectively detachably connected with the upper parts of the four connecting blocks, the upper ends of the four upper supporting rods are respectively detachably connected with the bedstead pipes in a group, the upper ends of the four lower supporting rods are respectively detachably connected with the lower parts of the four connecting blocks, and the lower ends of the four lower supporting rods are respectively used for contacting with the ground.

In one example, two ends of the two longitudinal rods are respectively fixedly connected with the corresponding connecting blocks; the two cross bars comprise a first cross bar, a second cross bar and a middle connecting piece, wherein the middle connecting piece is a U-shaped connecting piece which is arranged along the horizontal direction and is outwards opened, one end of the first cross bar extends into one end of the middle connecting piece and is fixedly connected with the upper side wall and the lower side wall of the middle connecting piece, the other end of the first cross bar is rotationally connected with a corresponding connecting block, one end of the second cross bar extends into the other end of the middle connecting piece and is rotationally connected with the upper side wall and the lower side wall of the middle connecting piece, and the other end of the second cross bar is rotationally connected with the corresponding connecting block; when the foldable rectangular frame is folded, the middle connecting pieces of the two cross bars are close to each other in opposite directions and drive the first cross bar and the second cross bar to rotate inwards to fold, so that the two longitudinal bars are urged to be close together in opposite directions.

Further, an elastic self-locking piece is arranged at one end of the second cross rod, which is rotationally connected with the middle connecting piece, a lock hole penetrating through the wall body is formed in the upper side wall or the lower side wall of the middle connecting piece, when the foldable rectangular frame is in an unfolding state, the elastic self-locking piece is inserted into the lock hole, so that the second cross rod and the middle connecting piece are locked together, and at the moment, the foldable rectangular frame cannot be folded; and the lock hole is internally provided with an unlocking button in a sliding manner, the unlocking button is in propping fit with the insertion end of the elastic self-locking piece, the pressing part of the unlocking button is exposed out of the lock hole, and when the pressing part is pressed, the unlocking button moves inwards and drives the insertion end of the elastic self-locking piece to be separated from the lock hole.

Further, the first cross bar and the second cross bar are positioned on the same straight line when the foldable rectangular frame is in an unfolding state, the end of the second cross bar extending into the middle connecting piece is rotationally connected with the middle of the upper side wall and the lower side wall of the middle connecting piece by the adapter close to the outer side, and the rotational connection position is more outward than the fixed connection position of the first cross bar and the middle connecting piece on the one hand, and the distances from two connecting blocks which are rotationally connected with the first cross bar and the second cross bar on the other hand are equal.

Further, an introduction bevel opening positioned at the outer side of the lock hole is arranged on the inner surface of the upper side wall or the lower side wall of the middle connecting piece, and the introduction bevel opening can guide the elastic self-locking piece to be inserted into the lock hole when the foldable rectangular frame is unfolded.

In another example, two ends of the two cross bars are respectively and fixedly connected with the corresponding connecting blocks, the two longitudinal bars are respectively set as a first longitudinal bar and a second longitudinal bar, wherein one end of the first longitudinal bar is rotationally connected with the corresponding connecting block, the other end of the first longitudinal bar is in pluggable connection with the corresponding connecting block, one end of the second longitudinal bar opposite to the rotational connecting end of the first longitudinal bar is rotationally connected with the corresponding connecting block, and one end of the second longitudinal bar opposite to the pluggable connecting end of the first longitudinal bar is in pluggable connection with the corresponding connecting block; when the foldable rectangular frame is folded, the pluggable connecting end of the first longitudinal rod and the pluggable connecting end of the second longitudinal rod are respectively pulled out of the corresponding connecting blocks and then are folded inwards in a rotating way, and the two cross rods are oppositely closed together.

Further, a limiting marble is arranged at the outer side of the pluggable connecting end of the first vertical rod, a limiting hole for inserting the limiting marble is formed in a connecting block corresponding to the pluggable connecting end of the first vertical rod, an unlocking marble which is staggered with the corresponding connecting block and is in linkage connection with the limiting marble is arranged at the inner side of the pluggable connecting end of the first vertical rod, and the limiting marble can be separated from the limiting hole by pressing the unlocking marble; the pluggable connecting end of the second longitudinal rod is also tensioned on the corresponding connecting block through the elastic rope.

Or the pluggable connecting end of the first longitudinal rod and the pluggable connecting end of the second longitudinal rod are respectively tensioned on the corresponding connecting blocks through elastic ropes.

Furthermore, the two longitudinal rods are respectively arranged on the inner sides below the two bedstead pipes in parallel, and are positioned at the same horizontal height position, and the two transverse rods are also positioned at the same horizontal height position.

Further, four connecting blocks are located at the same horizontal height position, four upper supporting rods are inclined supporting rods with equal length and symmetrically arranged, four lower supporting rods are telescopic inclined supporting rods with equal length and symmetrically arranged, and foot pads used for being in contact with the ground are arranged at the lower ends of the four lower supporting rods.

Further, the upper ends of the four upper struts are fixedly connected with clamping pieces with arc clamping sleeve parts, the arc clamping sleeve parts of the clamping pieces are respectively and detachably clamped on the corresponding bedstead pipes, and the sizes of the arc clamping sleeve parts are matched with the outer diameters of the bedstead pipes; in addition, four upper supporting rods and four lower supporting rods are all tensioned on the corresponding connecting blocks through elastic ropes.

Furthermore, the two sides of the bed surface are respectively sleeved on the two bedstead pipes through the sleeve penetrating parts arranged on the bed surface, the two bedstead pipes are composed of a plurality of sections of section pipes, in each bedstead pipe, every two adjacent sections of section pipes are detachably connected with each other in an inserting mode, all the section pipes are also tensioned together through an elastic rope penetrating through each section pipe, two ends of the elastic rope are respectively connected with a fixing plug, and the two fixing plugs are respectively inserted into the outer ends of the two sections of section pipes located at the outermost side.

Further, the foldable four-corner support frame is provided with two foldable four-corner support frames, and the foldable four-corner support frames are arranged at the lower ends of the two bedstead pipes at intervals along the length direction.

Compared with the prior art, the utility model has the following beneficial effects:

Firstly, the foldable four-corner support frame arranged at the lower ends of the two bedstead pipes can provide more stable support performance for the folding bed, in particular, four upper support rods and four lower support rods in the foldable four-corner support frame provide support at four diagonal positions along the up-down direction of the folding bed, two transverse rods in the foldable four-corner support frame provide support at two parallel interval positions along the transverse direction (i.e. the width direction) of the folding bed, and two longitudinal rods in the foldable four-corner support frame provide support at two parallel interval positions along the longitudinal direction (i.e. the length direction) of the folding bed.

In the utility model, the bed surface is folded and rolled together after being disassembled, the two bed frame pipes are disassembled and split into a plurality of sections of joint pipes to be folded together for storage, and the four upper support rods and the four lower support rods are disassembled and folded together for storage, and the foldable rectangular frame can also be folded and folded together, so that the whole folding bed has small volume after being folded and stored, is beneficial to saving occupied space and is convenient to carry.

Drawings

Fig. 1 is a schematic perspective view of a self-contained folding bed according to the utility model.

Fig. 2 is a schematic view of the structure of the bed surface in the present utility model.

Fig. 3 is a schematic view of the structure of the bed frame according to the present utility model.

Fig. 4 is a schematic view showing an unfolded state of the foldable four-corner support frame according to the first example of the present utility model.

Fig. 5 is a schematic view showing the upper and lower poles of the foldable four-corner support frame according to the first example of the present utility model in a disassembled state.

Fig. 6 is a schematic top view of the first rail or the second rail of fig. 4.

Fig. 7 is a schematic cross-sectional view of E-E of fig. 6.

Fig. 8 is an exploded view of the first rail or the second rail of fig. 4.

Fig. 9 is a schematic folding view of a foldable quadrangle support frame according to a first example of the present utility model.

Fig. 10 is a schematic view showing a folded state of two bed frame tubes according to the present utility model.

Fig. 11 is a schematic view of the folding bed of the present utility model in a fully folded state.

Fig. 12 is a schematic view showing an unfolded state of the foldable four-corner support frame according to the second example of the present utility model.

Fig. 13 is an enlarged schematic view of F in fig. 12.

Fig. 14 is a disassembled schematic of fig. 12.

Fig. 15 is a schematic structural view of a foldable quadrangle support frame according to a third example of the present utility model.

Detailed Description

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

As shown in fig. 1, 2, 3 and 11, the folding bed provided by the utility model comprises a bed surface 1 and a bed frame 2.

The bed frame 2 comprises two bed frame pipes 3a, 3b arranged in parallel at intervals along the horizontal direction, the bed surface 1 is made of flexible foldable materials, for example, cloth, and two sides of the bed surface 1 are respectively detachably connected with the two bed frame pipes 3a, 3 b.

The bed frame 2 further comprises at least one foldable quadrangle support frame 4 arranged at the lower ends of the two bed frame pipes 3a, 3 b. The foldable quadrangle support frame 4 comprises a foldable rectangular frame 41, four upper struts 42a, 42b, 42c, 42d and four lower struts 43a, 43b, 43c, 43d. The foldable rectangular frame 41 includes: two side rails 411, 412, two cross rails 413, 414, and four attachment blocks 415, 416, 417, 418. The two vertical rods 411, 412 are respectively arranged below the two bedstead pipes 3a, 3b in parallel, the two cross rods 413, 414 are respectively and vertically arranged between the two ends of the two vertical rods 411, 412, the four connecting blocks 415, 416, 417, 418 respectively connect the two vertical rods 411, 412 with the adjacent ends of the two cross rods 413, 414, the lower ends of the four upper supporting rods 42a, 42b, 42c, 42d are respectively and detachably inserted into the upper parts of the four connecting blocks 415, 416, 417, 418, the upper ends of the four upper supporting rods 42a, 42b, 42c, 42d are respectively and detachably connected with the bedstead pipes 3a or 3b in groups, and the upper ends of the four lower supporting rods 43a, 43b, 43c, 43d are respectively and detachably inserted into the lower parts of the four connecting blocks 415, 416, 417, 418, and the lower ends of the four lower supporting rods 43a, 43b, 43c, 43d are respectively used for contacting the ground.

When the folding bed is unfolded and used on the ground, the four upper struts 42a, 42b, 42c, 42d and the four lower struts 43a, 43b, 43c, 43d provide support in the up-down direction of the folding bed at four diagonal positions, the two cross bars 413, 414 provide support in the transverse direction W (i.e., the width direction) of the folding bed at two parallel spaced positions, and the two longitudinal bars 411, 412 provide support in the longitudinal direction L (i.e., the length direction) of the folding bed at two parallel spaced positions, so that stability of the folding bed in unfolded and use can be ensured.

As shown in fig. 4, 5, 6, 7, 8 and 9, in the first example of the foldable four-corner support frame 4 of the present utility model, two ends of two longitudinal bars 411, 412 are fixedly connected to corresponding connection blocks 415, 416, 417, 418, respectively. Both crossbars 413, 414 include a first crossbar 34a, a second crossbar 34b, and an intermediate connection 34c. The middle connecting piece 34c is a U-shaped connecting piece which is arranged along the horizontal direction and is opened outwards, one end of the first cross rod 34a extends into one end of the middle connecting piece 34c and is fixedly connected with the upper side wall 34c 1 and the lower side wall 34c2 of the middle connecting piece 34c, the other end of the first cross rod 34a is rotatably connected with the corresponding connecting block 415 or 416, one end of the second cross rod 34b extends into the other end of the middle connecting piece 34c and is rotatably connected with the upper side wall 34c 1 and the lower side wall 34c2 of the middle connecting piece 34c, and the other end of the second cross rod 34b is rotatably connected with the corresponding connecting block 417 or 418.

The end of the second cross bar 34b, which is rotatably connected with the middle connecting piece 34c, is provided with an elastic self-locking piece 5, the lower side wall 34c2 of the middle connecting piece 34c is provided with a locking hole 34c3 penetrating through the wall body, when the foldable rectangular frame 41 is in an unfolded state, the elastic self-locking piece 5 is inserted into the locking hole 34c3, so that the second cross bar 34b and the middle connecting piece 34c are locked together, and at the moment, the foldable rectangular frame 41 cannot be folded, so that the stability of the foldable rectangular frame 41 in unfolding use can be ensured.

The lock hole 34c3 is slidably provided with an unlocking button 6 which is in abutting fit with the insertion end of the elastic self-locking member 5, the pressing portion 61 of the unlocking button 6 is exposed out of the lock hole 34c3, when the pressing portion 61 is pressed, the unlocking button 6 moves inwards and urges the insertion end of the elastic self-locking member 5 to be out of the lock hole 34c3, at this time, the foldable rectangular frame 41 is in a foldable state, specifically, when the foldable rectangular frame 41 is folded, the intermediate connecting members 34c of the two cross bars 413 and 414 approach each other and drive the respective first cross bar 34a and second cross bar 34b to rotate inwards to fold, and further urge the two longitudinal bars 411 and 412 to approach each other.

The first cross bar 34a and the second cross bar 34B are positioned on the same straight line when the foldable rectangular frame 41 is in the unfolded state, the end of the second cross bar 34B extending into the middle connecting piece 34c is rotatably connected with the middle of the upper and lower side walls 34c 1, 34c2 of the middle connecting piece 34c by the adapter 7, and the rotation connecting position A1 is more outside than the fixed connecting position B1 of the first cross bar 34a and the middle connecting piece 34c, and the distances from two connecting blocks 415 and 417/416 and 418 which are rotatably connected with the first cross bar 34a and the second cross bar 34B are equal, so that the first cross bar 34a and the second cross bar 34B can be ensured to be in the flush posture after being folded.

The lower side wall 34c2 of the intermediate connecting member 34c is provided on the inner surface thereof with a lead-in bezel 34c4 located outside the lock hole 34c3, the lead-in bezel 34c4 guiding the insertion of the elastic self-locking member 5 into the lock hole 34c3 when the foldable rectangular frame 41 is unfolded. Of course, in other alternatives, the locking hole 34c3 and the lead-in bevel 34c4 may be provided on the upper side wall 34c 1 of the intermediate connector 34 c.

As shown in fig. 12, 13 and 14, in the second example of the foldable four-corner support frame 4 of the present utility model, two ends of two cross bars 413, 414 are fixedly connected to corresponding connection blocks 415, 416, 417, 418, respectively, and two longitudinal bars 411, 412 are respectively set as a first longitudinal bar 411 and a second longitudinal bar 412, wherein one end of the first longitudinal bar 411 is rotatably connected to the corresponding connection block 415, the other end of the first longitudinal bar 411 is removably connected to the corresponding connection block 416, one end of the second longitudinal bar 412 opposite to the rotatably connected end of the first longitudinal bar 411 is rotatably connected to the corresponding connection block 418, and one end of the second longitudinal bar 412 opposite to the removably connected end of the first longitudinal bar 411 is removably connected to the corresponding connection block 417.

The outer side of the pluggable connecting end of the first longitudinal rod 411 is provided with a limiting marble 8, and the connecting block 416 corresponding to the pluggable connecting end of the first longitudinal rod 411 is provided with a limiting hole 4161 for inserting the limiting marble 8, so that the pluggable connecting end of the first longitudinal rod 411 cannot be automatically separated in use; the pluggable connection end of the second side rail 412 is also pulled tightly against the corresponding connection block 417 by the bungee cord 200 such that the pluggable connection end of the second side rail 412 is not free to pull out during use. Thereby, it can ensure the stability of the foldable rectangular frame 41 when unfolded for use.

The inner side of the pluggable connection end of the first vertical rod 411 is provided with unlocking marble 9 which is staggered with the corresponding connection block 416 and is in linkage connection with the limiting marble 8, and the limiting marble 8 can be separated from the limiting hole 4161 by pressing the unlocking marble 9, at this time, the pluggable connection end of the first vertical rod 411 can be pulled out of the connection block 416. In this structure, the setting of the unlocking marble 9 can facilitate the unlocking operation of the spacing marble 8.

When the foldable rectangular frame 41 is folded, the unlocking marble 9 is pressed first to enable the limiting marble 8 to be separated from the limiting hole 4161, then the pluggable connecting end of the first longitudinal rod 411 and the pluggable connecting end of the second longitudinal rod 412 are respectively pulled out of the corresponding connecting blocks 416 and 417 and then are rotated inwards to be folded, and finally the two cross rods 413 and 414 are oppositely closed together.

As shown in fig. 15, in a third example of the foldable four-corner support stand 4 of the present utility model, this example is different from the second example in that: the pluggable connection end of the first side rail 411 and the pluggable connection end of the second side rail 412 are respectively tensioned on the corresponding connection blocks 416, 417 by the elastic cords 101, 102, so that the pluggable connection end of the first side rail 411 and the pluggable connection end of the second side rail 412 do not pull out by themselves during use. When the foldable rectangular frame 41 needs to be folded, only the pluggable connection end of the first longitudinal bar 411 and the pluggable connection end of the second longitudinal bar 412 need to be forced to pull out the corresponding connection blocks 416 and 417 respectively, and then to rotate inwards for folding, and then the two cross bars 413 and 414 are close together in opposite directions.

As shown in fig. 3, the two vertical bars 411, 412 are respectively disposed in parallel below and inside the two bed frame pipes 3a, 3b, and the two vertical bars 411, 412 are at the same horizontal level, and the two cross bars 413, 414 are also at the same horizontal level.

As shown in fig. 4, the four connection blocks 415, 416, 417, 418 are located at the same horizontal height, the four upper struts 42a, 42b, 42c, 42d are all inclined struts with equal length and symmetrically arranged, the four lower struts 43a, 43b, 43c, 43d are all telescopic inclined struts with equal length and symmetrically arranged, and the lower ends of the four lower struts 43a, 43b, 43c, 43d are all provided with foot pads for contacting with the ground so as to increase the stability of the ground.

As shown in fig. 3 and 4, the upper ends of the four upper struts 42a, 42b, 42c, 42d are fixedly connected with a clamping member 10 having an arc clamping sleeve portion 100, the arc clamping sleeve portion 100 of each clamping member 10 is respectively and detachably clamped on the corresponding bedstead pipe 3a, 3b, and the size of the arc clamping sleeve portion 100 is matched with the outer diameter of the bedstead pipe 3a, 3b, so that the bedstead pipe 3a, 3b cannot be loosened in use.

As shown in fig. 5, the four upper struts 42a, 42b, 42c, 42d are all tensioned on the corresponding connection blocks 415, 416, 417, 418 by the elastic ropes 103, 104, 105, 106, and the four lower struts 43a, 43b, 43c, 43d are all tensioned on the corresponding connection blocks 415, 416, 417, 418 by the elastic ropes 201, 202, 203, 204, so that the stability of the four upper struts 42a, 42b, 42c, 42d and the four lower struts 43a, 43b, 43c, 43d when the folding bed is unfolded and used can be improved, and the four upper struts 42a, 42b, 42c, 42d and the four lower struts 43a, 43b, 43c, 43d can be completely separated from the foldable rectangular frame 41 when the folding bed is disassembled.

As shown in fig. 1 and 2, two sides of the bed surface 1 are respectively sleeved on the two bedstead pipes 3a and 3b through sleeve penetrating parts 11 and 12 arranged on the bed surface, and in order not to influence the arc-shaped clamping sleeve parts 100 of the clamping pieces 10 to be clamped on the two bedstead pipes 3a and 3b, gaps 110 and 120 are arranged on the sleeve penetrating parts 11 and 12 corresponding to the clamping sleeve positions.

As shown in fig. 3 and 10, two bed frame pipes 3a and 3b are composed of a plurality of sections of joint pipes 300, in each bed frame pipe, two adjacent sections of joint pipes 300 are detachably connected with each other, all the joint pipes 300 are also tensioned together by an elastic rope 107 penetrating through each joint pipe, two ends of the elastic rope 107 are respectively connected with a fixing plug 400, and the two fixing plugs 400 are respectively inserted into the outer ends of the two sections of joint pipes 300 positioned at the outermost side. In this way, each section of the section pipe 300 will not loose automatically in use, and meanwhile, when the folding bed needs to be folded and stored, the two bedstead pipes 3a and 3b can be split into multiple sections for storage.

As shown in fig. 1 and 3, the number of foldable quadrangular supporting frames 41 can be determined according to the lengths of the two frame pipes 3a, 3 b. In a preferred embodiment of the present utility model, the foldable four-corner support frame 41 has two, which are disposed at the lower ends of the two frame tubes 3a, 3b at intervals in the length direction.

The foregoing description is only illustrative of the preferred embodiments of the present utility model and is not intended to limit the scope of the utility model, i.e., the utility model is not limited to the specific embodiments described herein, but is to be accorded the full scope of the claims.

Claims (13)

1. The folding bed comprises a bed surface and a bed frame, wherein the bed frame comprises two bed frame pipes which are arranged in parallel at intervals along the horizontal direction, the bed surface is made of flexible foldable materials, and two sides of the bed surface are respectively detachably connected with the two bed frame pipes; the method is characterized in that: the folding rectangular frame comprises two longitudinal rods, two transverse rods and four connecting blocks, wherein the two longitudinal rods are respectively arranged below the two bedstead pipes in parallel, the two transverse rods are respectively and vertically arranged between two ends of the two longitudinal rods, the four connecting blocks are respectively used for connecting adjacent ends of the two longitudinal rods and the two transverse rods together, the lower ends of the four upper supporting rods are respectively detachably connected with the upper parts of the four connecting blocks, the upper ends of the four upper supporting rods are respectively detachably connected with the bedstead pipes in a group, the upper ends of the four lower supporting rods are respectively detachably connected with the lower parts of the four connecting blocks, and the lower ends of the four lower supporting rods are respectively used for contacting with the ground.

2. A folding bed according to claim 1, characterized in that: two ends of the two longitudinal rods are fixedly connected with the corresponding connecting blocks respectively; the two cross bars comprise a first cross bar, a second cross bar and a middle connecting piece, wherein the middle connecting piece is a U-shaped connecting piece which is arranged along the horizontal direction and is outwards opened, one end of the first cross bar extends into one end of the middle connecting piece and is fixedly connected with the upper side wall and the lower side wall of the middle connecting piece, the other end of the first cross bar is rotationally connected with a corresponding connecting block, one end of the second cross bar extends into the other end of the middle connecting piece and is rotationally connected with the upper side wall and the lower side wall of the middle connecting piece, and the other end of the second cross bar is rotationally connected with the corresponding connecting block; when the foldable rectangular frame is folded, the middle connecting pieces of the two cross bars are close to each other in opposite directions and drive the first cross bar and the second cross bar to rotate inwards to fold, so that the two longitudinal bars are urged to be close together in opposite directions.

3. A folding bed according to claim 2, characterized in that: an elastic self-locking piece is arranged at one end of the second cross rod, which is rotationally connected with the middle connecting piece, a lock hole penetrating through the wall body is formed in the upper side wall or the lower side wall of the middle connecting piece, when the foldable rectangular frame is in an unfolding state, the elastic self-locking piece is inserted into the lock hole, so that the second cross rod and the middle connecting piece are locked together, and at the moment, the foldable rectangular frame cannot be folded; and the lock hole is internally provided with an unlocking button in a sliding manner, the unlocking button is in propping fit with the insertion end of the elastic self-locking piece, the pressing part of the unlocking button is exposed out of the lock hole, and when the pressing part is pressed, the unlocking button moves inwards and drives the insertion end of the elastic self-locking piece to be separated from the lock hole.

4. A folding bed according to claim 3, characterized in that: the first cross rod and the second cross rod are positioned on the same straight line when the foldable rectangular frame is in an unfolding state, the end, extending into the middle connecting piece, of the second cross rod is rotationally connected with the middle of the upper side wall and the lower side wall of the middle connecting piece through an adapter, the outer side of the middle of the upper side wall and the outer side of the middle connecting piece is located at the rotational connecting position, on one hand, compared with the fixed connecting position of the first cross rod and the middle connecting piece, on the other hand, the distance between the two connecting blocks which are rotationally connected with the first cross rod and the second cross rod is equal.

5. A folding bed according to claim 3, characterized in that: the inner surface of the upper side wall or the lower side wall of the middle connecting piece is provided with a leading-in bevel opening positioned at the outer side of the lock hole, and the leading-in bevel opening can guide the elastic self-locking piece to be inserted into the lock hole when the foldable rectangular frame is unfolded.

6. A folding bed according to claim 1, characterized in that: two ends of the two cross bars are respectively and fixedly connected with the corresponding connecting blocks, the two longitudinal bars are respectively set into a first longitudinal bar and a second longitudinal bar, one end of the first longitudinal bar is rotationally connected with the corresponding connecting block, the other end of the first longitudinal bar is in pluggable connection with the corresponding connecting block, one end of the second longitudinal bar opposite to the rotational connecting end of the first longitudinal bar is rotationally connected with the corresponding connecting block, and one end of the second longitudinal bar opposite to the pluggable connecting end of the first longitudinal bar is in pluggable connection with the corresponding connecting block; when the foldable rectangular frame is folded, the pluggable connecting end of the first longitudinal rod and the pluggable connecting end of the second longitudinal rod are respectively pulled out of the corresponding connecting blocks and then are folded inwards in a rotating way, and the two cross rods are oppositely closed together.

7. A folding bed according to claim 6, characterized in that: the outer side of the pluggable connecting end of the first longitudinal rod is provided with a limiting marble, the connecting block corresponding to the pluggable connecting end of the first longitudinal rod is provided with a limiting hole for inserting the limiting marble, the inner side of the pluggable connecting end of the first longitudinal rod is provided with an unlocking marble which is staggered with the corresponding connecting block and is in linkage connection with the limiting marble, and the limiting marble can be separated from the limiting hole by pressing the unlocking marble; the pluggable connecting end of the second longitudinal rod is also tensioned on the corresponding connecting block through the elastic rope.

8. A folding bed according to claim 6, characterized in that: the pluggable connecting end of the first longitudinal rod and the pluggable connecting end of the second longitudinal rod are respectively tensioned on the corresponding connecting blocks through elastic ropes.

9. A folding bed according to any one of claims 1 to 8, characterized in that: the two longitudinal rods are respectively arranged on the inner sides of the lower parts of the two bedstead pipes in parallel, and are positioned at the same horizontal height position, and the two transverse rods are also positioned at the same horizontal height position.

10. A folding bed according to any one of claims 1 to 8, characterized in that: four connecting blocks are located at the same horizontal height position, four upper supporting rods are inclined supporting rods with equal length and symmetrically arranged, four lower supporting rods are telescopic inclined supporting rods with equal length and symmetrically arranged, and foot pads used for being in contact with the ground are arranged at the lower ends of the four lower supporting rods.

11. A folding bed according to claim 1, characterized in that: the upper ends of the four upper struts are fixedly connected with clamping pieces with arc clamping sleeve parts, the arc clamping sleeve parts of the clamping pieces are respectively and detachably clamped on the corresponding bedstead pipes, and the sizes of the arc clamping sleeve parts are matched with the outer diameters of the bedstead pipes; in addition, four upper supporting rods and four lower supporting rods are all tensioned on the corresponding connecting blocks through elastic ropes.

12. A folding bed according to claim 1, characterized in that: the two sides of the bed surface are respectively sleeved on the two bedstead pipes through the sleeve penetrating parts arranged on the bed surface, the two bedstead pipes are composed of a plurality of sections of section pipes, in each bedstead pipe, every two adjacent sections of section pipes are detachably connected with each other in an inserting mode, all the section pipes are also tensioned together through an elastic rope penetrating through each section pipe, two ends of the elastic rope are respectively connected with a fixing plug, and the two fixing plugs are respectively inserted into the outer ends of the two sections of section pipes located at the outermost side.

13. A folding bed according to any one of claims 1 to 8, characterized in that: the foldable four-corner support frames are arranged at the lower ends of the two bedstead pipes at intervals along the length direction.