CN116639175A

CN116639175A - Child cart

Info

Publication number: CN116639175A
Application number: CN202310467554.1A
Authority: CN
Inventors: 王俊马; 吉跃
Original assignee: Goodbaby Child Products Co Ltd
Current assignee: Goodbaby Child Products Co Ltd
Priority date: 2023-04-27
Filing date: 2023-04-27
Publication date: 2023-08-25

Abstract

The invention relates to a child stroller, which comprises a frame, a front bracket, a side rod frame, a rear bracket, a supporting frame, a rear supporting frame, a push rod frame, a connecting frame and a bottom supporting frame, wherein the lower part of the side rod frame is rotationally connected with the upper part of the front bracket, the upper part of the side rod frame is rotationally connected to the push rod frame, and the upper part of the supporting frame is rotationally connected with the lower part of the side rod frame; the rear bracket can be arranged on the support frame in a sliding manner along the length extension direction of the support frame; the rear part of the bottom support frame is rotationally connected with the lower part of the support frame, the front part of the bottom support frame is rotationally connected with a first sliding piece, and the first sliding piece is slidingly arranged on the front support frame; the rear support frame is rotationally connected with the support frame, the upper part of the rear support frame is rotationally connected with the lower part of the push rod frame, the lower part of the rear support frame is rotationally connected with a second sliding piece, and the second sliding piece is slidingly arranged on the bottom support frame; the connecting frame is rotationally connected between the second sliding piece and the rear support, and the rear support can slide upwards relative to the support frame to be folded when the frame is folded.

Description

Child cart

Technical Field

The invention relates to the field of children products, in particular to a child trolley.

Background

The existing child cart has various structures, different rod pieces and different connection relations, correspondingly different folding principles, different folded forms and different folded sizes, and the aim of continuously pursuing by the technicians in the field is to ensure good stability and normal use performance of the cart, so that the structure of the cart frame is as simple as possible, the folding operation is more convenient, and the folded volume is as small as possible.

Disclosure of Invention

The invention aims to provide a novel child stroller.

In order to achieve the above purpose, the invention adopts the following technical scheme: a child stroller comprising a frame having an expanded configuration and a collapsed configuration, a front wheel assembly and a rear wheel assembly disposed at a bottom of the frame, the frame comprising:

the front support extends obliquely backwards from bottom to top, and the front wheel assembly is arranged at the lower part of the front support;

the side rod frame extends backwards and obliquely from bottom to top, and the lower part of the side rod frame is rotationally connected with the upper part of the front bracket;

the push rod frame extends backwards in an inclined mode from bottom to top, and the upper part of the side rod frame is rotationally connected to the push rod frame;

the support frame extends forwards in a tilting way from bottom to top, and the upper part of the support frame is rotationally connected with the lower part of the side rod frame;

the rear support extends forwards in an inclined mode from bottom to top, the rear wheel assembly is arranged at the lower part of the rear support, and the rear support can be arranged on the support in a sliding mode along the length extending direction of the support;

the bottom support frame extends along the front-back direction, the rear part of the bottom support frame is rotationally connected with the lower part of the support frame, the front part of the bottom support frame is rotationally connected with a first sliding piece, and the first sliding piece is slidably arranged on the front support frame along the length extending direction of the front support frame;

the rear support extends along the up-down direction, the rear support is rotationally connected with the supporting frame, the upper part of the rear support is rotationally connected with the lower part of the push rod frame, the lower part of the rear support is rotationally connected with a second sliding piece, and the second sliding piece can be slidingly arranged on the bottom support along the length extending direction of the bottom support;

and one end part of the connecting frame is rotationally connected to the second sliding piece, and the other end part of the connecting frame is rotationally connected to the rear bracket.

Preferably, the support frame and the rear support frame are parallel to each other or extend along the same length direction, the support frame and the rear support frame are connected with each other in a sliding manner along the length direction, and the rear support frame slides upwards along the support frame in the process of converting the unfolded state into the folded state.

Preferably, in the process of converting the frame from the unfolded state to the folded state, the rear support frame and the side rod frames turn backwards, the first sliding piece slides upwards along the front support frame, the second sliding piece slides forwards along the bottom support frame, and the rear support frame slides upwards along the support frame, so that the front support frame, the bottom support frame, the rear support frame, the side rod frames and the push rod frames are folded together along the front-rear direction.

In some embodiments, the frame is in a folded state, the rear wheel assembly is suspended, and the lower part of the support frame and the lower part of the push rod frame are supported on the ground together.

In some embodiments, the frame further comprises a seat frame extending in a front-rear direction in a deployed state, a rear portion of the seat frame is rotatably connected to the rear bracket, and a third slider is rotatably provided on the side rod frame and slidably provided on the seat frame in a length extending direction of the seat frame.

In some embodiments, the front bracket comprises two front struts which are respectively arranged at the left side and the right side and extend along the up-down direction; the side lever frame is including locating left and right sides and all along two side levers that upper and lower direction extends, the support frame is including locating two bracing pieces of left and right sides about locating the frame, on each side about the frame, the upper portion of preceding branch with the lower part of side lever rotates ground around first rotation central line and is connected, the upper portion of bracing piece with the lower part of side lever rotates ground around the second rotation central line and is connected, first rotation central line with second rotation central line is parallel or collinearly extends each other.

In some embodiments, the lower part of the side lever is provided with a first connector and a second connector, the upper part of the front support rod is fixedly provided with a third connector, the frame is in a unfolding state, the first connector extends downwards and forwards obliquely from the lower part of the side lever, the second connector extends downwards and backwards obliquely from the lower part of the side lever, the third connector extends downwards and backwards obliquely from the upper part of the front support rod, the first connector and the third connector are rotationally connected around a first rotation center line, the upper part of the support rod and the second connector are rotationally connected around a second rotation center line, the first rotation center line is positioned below the second rotation center line, and the upper end part of the front support rod and the lower end part of the side lever are mutually propped against each other.

In some embodiments, the rear bracket comprises two rear struts arranged on the left side and the right side, and a group of rear wheel assemblies are arranged at the bottom of each rear strut; the rear supporting rods and the supporting rods on the same side are mutually parallel or extend along the same length direction, the rear supporting rods and the supporting rods are connected in a sliding manner along the length direction, the connecting frame comprises two connecting rods which are respectively arranged on the left side and the right side, the bottom support frame comprises two bottom supporting rods which are respectively arranged on the left side and the right side and extend along the front-rear direction, the left side and the right side of the frame are respectively provided with a first sliding piece, and the first sliding piece can be arranged on the front supporting rods in a sliding manner; the second sliding piece can be arranged on the bottom supporting rod in a sliding mode, the front portion of the bottom supporting rod is rotationally connected to the first sliding piece, the rear portion of the bottom supporting rod is rotationally connected to the lower portion of the supporting rod around a third rotation center line, one end portion of the connecting rod is rotationally connected to the second sliding piece around a fourth rotation center line, and the other end portion of the connecting rod is rotationally connected to the rear supporting rod around a fifth rotation center line.

In some embodiments, the rear strut includes two rear struts which are respectively disposed at the left and right sides and all extend along the up-down direction, the push rod frame includes two push rods which are respectively disposed at the left and right sides and all extend along the up-down direction, on each side of the frame, the upper parts of the side rods are rotationally connected to the push rods around a sixth rotation center line, the rear struts are mutually intersected with the support rods and rotationally connected around a seventh rotation center line at the intersection, the upper parts of the rear struts are rotationally connected with the lower parts of the push rods around an eighth rotation center line, the lower parts of the rear struts are rotationally connected to the second sliding member around a ninth rotation center line, wherein the sixth rotation center line and the eighth rotation center line are mutually parallel, and the ninth rotation center line and the fourth rotation center line are mutually parallel or collinearly extended.

In some embodiments, the rear supporting rod is provided with a hollow rod cavity penetrating along the length direction of the rear supporting rod, the rear supporting rod can be sleeved on the supporting rod in a sliding fit manner along the length direction of the rear supporting rod, and the lower part of the supporting rod penetrates through the lower part of the rear supporting rod and is rotationally connected with the rear part of the bottom supporting rod.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: in the child stroller, the frame can slide upwards relative to the support frame in the folding process, so that the rear wheel assembly can be lifted upwards, the size of the folded frame is reduced, and convenience is brought to daily carrying and use of a user.

Drawings

FIG. 1 is a schematic perspective view of a stroller in an unfolded state according to an embodiment of the present invention;

FIG. 2 is a schematic side view of the child stroller of FIG. 1;

FIG. 3 is a schematic view of the center lines of rotation identified on the basis of FIG. 1;

FIG. 4 is a schematic perspective view of the child stroller of FIG. 1 in a semi-collapsed condition;

FIG. 5 is a schematic side view of the child stroller of FIG. 4;

FIG. 6 is a schematic perspective view of the child stroller of FIG. 1 in a collapsed configuration;

FIG. 7 is a schematic side elevational view of the stroller of FIG. 6;

wherein: 1. a front bracket; 11. a front strut; 12. a front cross bar; 13. a third connector;

2. a side rod frame; 21. a side bar; 22. a first connector; 23. a second connector;

3. a rear bracket; 31. a rear strut;

4. a support frame; 41. a support rod; 42. a rear cross bar; 43. a fourth connector;

5. a rear bracket; 51. a rear stay;

6. a push rod frame; 61. a push rod; 61a, push down rod; 61b, a middle push rod; 61c, pushing up the rod; 62. an upper cross bar; 63. a handle bar;

7. a connecting frame; 71. a connecting rod;

8. a bottom bracket; 81. a bottom stay;

9. a first slider; 10. a second slider;

20. a seat frame; 201. a seat rod; 202. a third slider;

30. a front wheel assembly; 40. and a rear wheel assembly.

Detailed Description

The technical scheme of the invention is further described below with reference to the attached drawings and specific embodiments.

The following description of the directions such as front, rear, left, right, up, down and the like is defined with reference to the directions that a user observes when pushing the stroller in a state where the frame of the stroller is unfolded, and only aims to clearly describe the relative positional relationship of the respective rods/members in the stroller.

Referring to fig. 1-7, a stroller includes a frame having an expanded configuration and a collapsed configuration, front and rear wheel assemblies 30, 40 disposed at a bottom portion of the frame, and a locking mechanism for locking the frame in the expanded configuration.

The frame comprises a front bracket 1, a side rod frame 2, a rear bracket 3, a supporting frame 4, a rear supporting frame 5, a push rod frame 6, a connecting frame 7 and a bottom supporting frame 8, wherein the front bracket 1 extends obliquely backwards from bottom to top and a front wheel assembly 30 is arranged at the bottom of the front bracket 1 when the frame is in an unfolded state as shown in fig. 1 to 3; the side rod frame 2 extends backwards and obliquely from bottom to top, and the lower part of the side rod frame 2 is rotationally connected with the upper part of the front bracket 1; the push rod frame 6 extends obliquely backwards from bottom to top, and the upper part of the side rod frame 2 is rotationally connected to the push rod frame 6; the support frame 4 and the rear bracket 3 extend obliquely forward from bottom to top, respectively, the rear wheel assembly 40 is provided at a lower portion of the rear bracket 3, and the rear bracket 3 is slidably provided on the support frame 4 along a length extending direction of the support frame 4, specifically, the support frame 4 and the rear bracket 3 are parallel to each other or extend along the same length direction, so that both are slidably connected to each other along the length direction.

The upper part of the supporting frame 4 is rotationally connected with the lower part of the side rod frame 2; the bottom bracket 8 extends in the front-rear direction, the rear part of the bottom bracket 8 is rotatably connected to the lower part of the support frame 4, the front part of the bottom bracket 8 is rotatably connected to the first slider 9, and the first slider 9 is slidably arranged on the front bracket 1 in the length extending direction of the front bracket 1; the rear support 5 is rotatably connected with the support frame 4, the upper part of the rear support 5 is rotatably connected with the lower part of the push rod frame 6, the lower part of the rear support 5 is rotatably connected with a second sliding piece 10, and the second sliding piece 10 can be slidably arranged on the bottom support 8 along the length extending direction of the bottom support 8; one end of the link 7 is rotatably connected to the second slider 10, and the other end thereof is rotatably connected to the rear bracket 3.

The frame further comprises a seat frame 20 extending in the fore-and-aft direction in the unfolded state, the rear part of the seat frame being rotatably connected to the rear stay 5, the side pole frame 2 being rotatably provided with a third slider 202, the third slider 202 being slidably provided on the seat frame 20 in the longitudinal extension direction of the seat frame 20.

Specifically, referring to the drawings, in this embodiment, the rods/members on the frame are arranged as follows:

the front bracket 1 comprises two front struts 11 which are respectively arranged at the left side and the right side and extend along the up-down direction, and a front cross rod 12 which is fixedly arranged between the lower parts of the two front struts 11 and extends along the left-right direction, and the front wheel assembly 30 is provided with two groups which are respectively arranged at the left side and the right side, wherein the front wheel assembly 30 is a universal wheel assembly and is arranged on the end part of the front cross rod 12.

The side bar frame 2 includes two side bars 21 which are respectively arranged at the left and right sides and extend along the up-down direction, the supporting frame 4 includes two supporting bars 41 which are respectively arranged at the left and right sides and extend along the up-down direction, the upper part of the front supporting bar 11 is rotationally connected with the lower part of the side bar 21 around a first rotation center line X1, the upper part of the supporting bar 41 is rotationally connected with the lower part of the side bar 21 around a second rotation center line X2, and the first rotation center line X1 and the second rotation center line X2 are mutually parallel or collinearly extended.

Here, referring to fig. 2, the lower part of the side bar 21 has a first connector 22 and a second connector 23, the upper part of the front strut 11 has a third connector 13, the first connector 22 extends downward and forward obliquely from the lower part of the side bar 21 in the unfolded state of the frame, the second connector 23 extends downward and backward obliquely from the lower part of the side bar 21, the third connector 13 extends downward and backward obliquely from the upper part of the front strut 11, the first connector 22 and the third connector 13 are rotatably connected around a first rotation center line X1, the upper part of the support bar 41 and the second connector 23 are rotatably connected around a second rotation center line X2, the first rotation center line X1 and the second rotation center line X2 are parallel to each other and the first rotation center line X1 is positioned below the second rotation center line X2, the upper end part of the front strut 11 and the lower end part of the side bar 21 are abutted against each other, and when the frame is folded, the lower part of the side bar 21 and the upper part of the front strut 11 can be separated from each other, thereby facilitating other rod members on the frame to be tightly folded between the front strut 11 and the side bar 21.

The rear bracket 3 includes two rear struts 31 which are respectively provided at the left and right sides and extend in the up-down direction, and a group of rear wheel assemblies 40 are respectively provided at the bottoms of the rear struts 31 at each side. The rear struts 31 and the support bars 41 on the same side extend parallel to each other or in the same length direction, and the rear struts 31 and the support bars 41 are slidably connected to each other in the length direction. In this embodiment, the rear strut 31 has a hollow rod cavity penetrating along its length direction, and the rear strut 31 is slidably fitted over the support rod 41, so that the rear strut 31 and the support rod 41 can slide relative to each other along its length direction. The rear wheel assembly 40 is mounted on the rear side of the rear strut 31. The support frame 4 further comprises a rear cross bar 42 fixedly arranged between the lower parts of the support bars 41 at two sides and extending along the left and right directions, the left and right end parts of the rear cross bar 42 are fixedly provided with fourth connectors 43 respectively, and the fourth connectors 43 extend forwards and downwards in a tilting manner when the frame is in a unfolding state so as to be rotationally connected with the rear part of the bottom support frame 8.

The connecting frame 7 includes two connecting rods 71 respectively disposed on the left and right sides, the bottom bracket 8 includes two bottom brackets 81 respectively disposed on the left and right sides and extending in the front and rear directions, the first sliding member 9 is slidably disposed on the front strut 11 along the length extending direction of the front strut 11, and the second sliding member 10 is slidably disposed on the bottom brackets 81 along the length extending direction of the bottom brackets 81, where the first sliding member 9 and the second sliding member 10 are sliding sleeves.

The front part of the bottom stay 81 is rotatably connected to the first slider 9, and the rear part of the bottom stay 81 is rotatably connected to the lower part of the support bar 41, specifically, rotatably connected to the fourth connector 43, about the third rotation center line X3; one end of the connecting rod 71 is rotatably connected to the second slider 10 about the fourth rotation center line X4, and the other end of the connecting rod 71 is rotatably connected to the rear strut 31 about the fifth rotation center line X5.

The push rod frame 6 includes two push rods 61 respectively arranged at the left and right sides and extending in the up-down direction, wherein the push rods 61 are telescopic rods, and specifically include a lower push rod 61a, a middle push rod 61b and an upper push rod 61c which are sequentially in sliding sleeve connection; the push rod frame 6 further includes an upper cross rod 62 fixed between the tops of the push rods 61c on both sides and extending in the left-right direction, and push rod bars 63 provided separately from left and right end portions of the upper cross rod 62 and extending forward. The rear bracket 5 includes two rear stay bars 51 which are respectively provided on the left and right sides and extend in the up-down direction, and on the left and right sides of the frame, the upper parts of the side bars 21 are rotatably connected to the lower push bars 61a around a sixth rotation center line X6; the rear stay 5 is located between the two sets of support rods 31 in the left-right direction, the rear stay 51 and the support rods 31 are intersected with each other and rotatably connected around a seventh rotation center line X7 at the intersection, the upper portion of the rear stay 51 is rotatably connected with the lower portion of the lower push rod 61a around an eighth rotation center line X8, the lower portion of the rear stay 51 is rotatably connected with the second slider 10 around a ninth rotation center line X9, wherein a sixth rotation center line X6 is located at the eighth rotation center line X8 in the length extending direction of the lower push rod 61 a; the ninth rotation center line X9 and the fourth rotation center line X4 extend parallel or collinear with each other; the seventh rotation center line X7 is located below the second rotation center line X2 in the length extending direction of the support lever 41, and the seventh rotation center line X7 is located above the fifth rotation center line X5.

The seat frame 20 includes two seat bars 201 respectively disposed on the left and right sides and extending in the front-rear direction, the rear portion of the seat bar 201 is rotatably connected to the upper portion of the rear stay 51, and a third slider 202 is rotatably connected to the side bar 21, and the third slider 202 is a sliding sleeve slidably fitted over the seat bar 201.

Referring to fig. 1 to 3, in the unfolded state of the vehicle frame, the upper part of the front bracket 1 abuts against the lower part of the side bar frame 2, the support frame 3 and the bottom bracket 8 extend forward from bottom to top to be supported below the rear of the side bar frame 2 and the front bracket 1, the rear bracket 3 is positioned at the lower part of the support frame 4, and the front wheel assembly 30 and the rear wheel assembly 40 are supported on the ground together.

When the frame needs to be folded, referring to fig. 4 and 5, an operator can hold the handle bars 63 at both sides with both hands and press down, so that the push rods 61 at both sides shorten the length along the length direction, meanwhile, the push rod frame 6 moves down integrally, drives the upper parts of the side rod frame 2 and the rear support frame 5 to move backward and downward, drives the lower part of the rear support frame 5 to move forward and upward, drives the second sliding piece 10 to move forward along the bottom support frame 8, and the rear support frame 3 slides upward along the support frame 4 under the action of the connecting frame 7, so that the bottom support frame 8, the rear support frame 3 and the support frame 4 are folded along the front and rear directions; the first slider 9 slides upward along the front bracket 1 and causes the front bracket 1 to retract rearward with the floor frame 8 in the front-rear direction.

The folded frame is shown in fig. 6 and 7, wherein the front bracket 1, the bottom bracket 8, the rear bracket 3, the support frame 4, the rear bracket 5, the side rod frame 2 and the push rod frame 6 are folded together along the front-rear direction, the two front wheel assemblies 30 are positioned between the rod assemblies on the left side and the right side of the frame along the left-right direction, the two rear wheel assemblies 40 are suspended in the air, the lower part of the support frame 4 and the lower part of the push rod frame 6 are jointly supported on the ground, and the self-standing of the folded frame is formed. The height of the folded frame is approximately consistent with the length of the support frame 3, the size is relatively small, and convenience is brought to daily storage and carrying of users.

The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and to implement the same, but are not intended to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a children's shallow, includes the frame that has expansion state and folding state, locates front wheel subassembly and rear wheel subassembly of frame bottom, its characterized in that: in the unfolded state, the frame comprises:

2. The stroller of claim 1, wherein: the support frame with the back support is parallel or extend along same length direction each other, the support frame with the back support is connected with each other in a sliding manner along length direction, the frame is from the in-process of expansion state to folding state conversion, the back support is followed the support frame upwards slides.

3. The stroller of claim 1, wherein: in the process of converting the frame from an unfolding state to a folding state, the rear support frame and the side rod frames turn backwards, the first sliding piece upwards slides along the front support frame, the second sliding piece forwards slides along the bottom support frame, and the rear support frame upwards slides along the support frame, so that the front support frame, the bottom support frame, the rear support frame, the side rod frames and the push rod frames are folded together along the front-rear direction.

4. A stroller according to claim 3, wherein: the frame is in a folding state, the rear wheel assembly is suspended, and the lower part of the support frame and the lower part of the push rod frame are jointly supported on the ground.

5. The stroller of claim 1, wherein: the frame also comprises a seat frame which extends along the front-back direction in the unfolded state, the rear part of the seat frame is rotationally connected to the rear supporting frame, a third sliding piece is rotationally arranged on the side rod frame, and the third sliding piece can be slidingly arranged on the seat frame along the length extending direction of the seat frame.

6. A stroller according to any one of claims 1 to 5, wherein: the front support comprises two front support rods which are respectively arranged at the left side and the right side and extend along the up-down direction; the side lever frame is including locating left and right sides and all along two side levers that upper and lower direction extends, the support frame is including locating two bracing pieces of left and right sides about locating the frame, on each side about the frame, the upper portion of preceding branch with the lower part of side lever rotates ground around first rotation central line and is connected, the upper portion of bracing piece with the lower part of side lever rotates ground around the second rotation central line and is connected, first rotation central line with second rotation central line is parallel or collinearly extends each other.

7. The stroller of claim 6, wherein: the lower part of side lever has first connector and second connector, the upper portion of preceding branch has set firmly the third connector, the frame is in under the state of expanding, first connector certainly the lower part of side lever is down and forward slope extension, the second connector certainly the lower part of side lever is down and backward slope extension, the third connector certainly the upper portion of preceding branch is down and backward slope extension, first connector with the third connector is around first rotation central line rotationally connected, the upper portion of bracing piece with the second connector is around second rotation central line rotationally connected, first rotation central line is located the below of second rotation central line, the upper end of preceding branch with the lower tip of side lever is mutually supported.

8. The stroller of claim 6, wherein: the rear support comprises two rear supporting rods which are respectively arranged at the left side and the right side, and a group of rear wheel assemblies are arranged at the bottom of each rear supporting rod; the rear supporting rod and the supporting rod on the same side are mutually parallel or extend along the same length direction, and the rear supporting rod and the supporting rod are mutually connected in a sliding way along the length direction,

the connecting frame comprises two connecting rods which are respectively arranged at the left side and the right side, the bottom support frame comprises two bottom support rods which are respectively arranged at the left side and the right side and extend along the front-rear direction, the first sliding piece is arranged on the front support rod in a sliding manner on each of the left side and the right side of the frame; the second sliding piece can be arranged on the bottom supporting rod in a sliding mode, the front portion of the bottom supporting rod is rotationally connected to the first sliding piece, the rear portion of the bottom supporting rod is rotationally connected to the lower portion of the supporting rod around a third rotation center line, one end portion of the connecting rod is rotationally connected to the second sliding piece around a fourth rotation center line, and the other end portion of the connecting rod is rotationally connected to the rear supporting rod around a fifth rotation center line.

9. The stroller of claim 8, wherein: the back strut is including locating left and right sides and all along two back vaulting poles that extend of upper and lower direction respectively, the push rod frame is including locating left and right sides and all along two push rods that extend of upper and lower direction respectively, on each side about the frame, the upper portion of side lever rotationally connect on the push rod around sixth rotation central line, back vaulting pole with the bracing piece is crisscross and rotationally connect around seventh rotation central line in the intersection, back vaulting pole upper portion with the lower part of push rod rotationally connects around eighth rotation central line, back vaulting pole lower part rotationally connect around ninth rotation central line in on the second slider, wherein, sixth rotation central line with eighth rotation central line is parallel to each other, ninth rotation central line with fourth rotation central line is parallel or collinearly extends each other.

10. The stroller of claim 8, wherein: the rear supporting rod is provided with a hollow rod cavity penetrating along the length direction of the rear supporting rod, the rear supporting rod can be sleeved on the supporting rod in a sliding fit manner along the length direction of the rear supporting rod, and the lower part of the supporting rod penetrates through the lower part of the rear supporting rod and is rotationally connected with the rear part of the bottom supporting rod.