CN107323511B

CN107323511B - Baby carriage frame

Info

Publication number: CN107323511B
Application number: CN201710681478.9A
Authority: CN
Inventors: 杨正帆
Original assignee: SUNNYLOVE BABY PRODUCTS ZHUHAI CO LTD
Current assignee: SUNNYLOVE BABY PRODUCTS ZHUHAI CO LTD
Priority date: 2017-08-10
Filing date: 2017-08-10
Publication date: 2023-06-27
Anticipated expiration: 2037-08-10
Also published as: CN107323511A

Abstract

The invention discloses a baby carriage frame, wherein a rear wheel folding mechanism is folded through bending of a connecting rod group, so that a rear foot rod is driven to be folded towards a front wheel frame direction by taking a pivot shaft connected with the rear foot rod as a rotation center, a rear wheel frame component is guided by the connecting rod group to be folded towards the front in the front process, the rear foot rod is led to be relatively folded towards the middle direction of a carriage body, and finally, two rear wheels can be folded between two front wheels, so that the whole width and the volume of the baby carriage frame are greatly reduced, and the problem that the width and the volume of the folded baby carriage frame are difficult to be reduced after the two rear wheels are respectively positioned at the outer sides of the two front wheels is solved. On the other hand, in the folding process of the baby carriage frame, under the driving of the first joint assemblies at the left side and the right side, the seat cushion supporting mechanism can be automatically folded by directly pulling the whole seat cushion supporting mechanism through the supporting plate by the linkage shaft rod positioned in the carriage body.

Description

Baby carriage frame

[ field of technology ]

The invention relates to a stroller frame.

[ background Art ]

The existing baby carriage frame mainly comprises a frame body with a plurality of folding joints, front wheels are respectively arranged on the left side and the right side of the front end of the bottom of the frame body, rear wheels are respectively arranged on the left side and the right side of the rear end of the bottom of the frame body, and the baby carriage frame can be unfolded and folded through the frame body with the plurality of folding joints. After the baby carriage is unfolded, the baby carriage can be taken by a baby, so that a adult can push the baby carriage on the road surface; after folding, the space occupied by the stroller frame can be reduced, so that the stroller frame can be stored and carried conveniently.

However, the existing stroller frame is designed to provide good stability and steering flexibility during movement, and the spacing between the two rear wheels of the stroller frame must be greater than the spacing between the two front wheels. Because the folding mechanism of the existing baby carriage frame can generate the function of folding front and back by utilizing the frame body with a plurality of folding joints, when the baby carriage frame is folded, two rear wheels with wider intervals are required to be positioned behind or outside two front wheels with narrower intervals, so that the whole width of the baby carriage frame is still bigger after being folded, the size of the baby carriage frame is difficult to be reduced to be smaller, and the problem of occupied space exists. In addition, in the existing stroller frame, a simple connecting rod assembly is adopted to support the bearing mechanism, so that the bearing capacity provided by the simple connecting rod assembly still has the defects, and potential safety hazards exist.

The invention is researched and proposed to overcome the defects of the prior art.

[ invention ]

The technical problem to be solved by the invention is to provide the baby carriage frame, optimize the whole structure and solve the problem that after the existing baby carriage frame is folded, two rear wheels are respectively positioned at the outer sides of the two front wheels.

In order to solve the above technical problems, the stroller frame of the present invention comprises:

the frame body comprises a front wheel frame, a seat cushion supporting frame, two first joint assemblies, two push rods, two second joint assemblies, a handle, a first cross rod, a second cross rod and a linkage shaft rod.

The front wheel frame comprises two front foot rods which are opposite in left and right direction and extend obliquely from front to back upwards, the two first joint assemblies are respectively arranged between the seat cushion support frame and the two front foot rods, seat cushion plates are arranged on the seat cushion support frame, the lower ends of the two push rods are respectively connected with the two first joint assemblies, the upper ends of the two push rods are respectively connected with the two second joint assemblies, the two ends of the handle are respectively connected with the two second joint assemblies, an operation assembly is arranged on the handle to control the first joint assemblies to correspondingly act with the second joint assemblies, the first cross rod and the second cross rod are arranged below the seat cushion support frame, the second cross rod is arranged on the front lower side of the first cross rod in parallel, the two ends of the first cross rod are connected between the two first joint assemblies, the second cross rod is connected between the two front foot rods, and the linkage shaft rod is arranged below the rear bottom surface of the seat cushion plates and connected between the two first joint assemblies and is in linkage with the first joint assemblies.

The two front wheel sets are respectively pivoted on the left side and the right side of the front end of the frame body, each front wheel set comprises a front wheel seat and a front wheel pivoted on the front wheel seat, and the front wheel seat is connected with the lower end of the front foot rod.

The seat cushion supporting mechanism can be movably assembled below the seat cushion plate and comprises a first arc-shaped plate, a second arc-shaped plate and a supporting plate, the upper end of the first arc-shaped plate is pivoted at the middle part of the bottom surface of the seat cushion plate, the lower end of the second arc-shaped plate is pivoted at the second cross rod, the upper end of the supporting plate is connected with the linkage shaft rod, and the lower ends of the first arc-shaped plate, the upper end of the second arc-shaped plate and the lower end of the supporting plate are coaxially pivoted.

The rear wheel folding mechanism is arranged at the rear side of the frame body and comprises two rear wheel frame components and two connecting rod groups.

The two rear wheel frame components can be movably assembled on the first cross rod, each rear wheel frame component comprises a rear wheel, a rear wheel seat, a rear foot rod and a connecting seat, the rear wheel is pivoted on one side of the rear wheel seat through a wheel shaft, the lower end of the rear foot rod is connected with the top of the rear wheel seat, an included angle formed by the rear foot rod and the wheel shaft of the rear wheel is an acute angle, the connecting seat is obliquely fixed on the first cross rod, the upper end of the rear foot rod is pivoted on the connecting seat, the connecting seat comprises a pivoting part, a fixedly connected part and a stopping part, the fixedly connected part is pivoted with the first cross rod, the connecting seat is pivoted with the upper end of the rear foot rod through the pivoting part and a pivot, the stopping part is positioned behind the upper end of the rear foot rod and used for limiting the angle of the rear foot rod relative to the connecting seat, the connecting seat is inclined from top to bottom to outside so that the two rear foot rods form a shape which is symmetrical from top to bottom of the front end, and the front wheel frame is inclined at a distance between the two front wheels, and the two front wheels are arranged between the two front wheels and the two front wheels are in a symmetrical shape, and the distance between the front wheels is large.

Each connecting rod group comprises a first connecting rod and a second connecting rod, one end of the first connecting rod is connected to the second cross rod, the other end of the first connecting rod is connected with one end of the second connecting rod through a first multidirectional connecting piece, and the other end of the second connecting rod is connected to the middle of the rear foot rod through a second multidirectional connecting piece.

And a limiting blocking part is arranged on the bottom end part of the first arc-shaped plate, below the pivot column and outside the top end of the second arc-shaped plate.

And the connecting rod groups are respectively arranged at two ends of the second cross rod and positioned at the outer sides of the rear foot rods and connected with the middle parts of the corresponding rear foot rods.

The telescopic support rod groups are respectively connected between the push rods on the left side and the right side of the frame body and the seat cushion support frame, each telescopic support rod group comprises a first support rod and a second support rod, the first support rod and the second support rod are arc-shaped rod pieces, one end of each first support rod is pivoted on the push rod, an arc-shaped slotted hole is formed in the side face of each first support rod, one end of each second support rod is pivoted on the side edge of the seat cushion support frame, the other end of each second support rod is movably connected to the other end of each first support rod, a limiting block is arranged at the other end of each second support rod, and the limiting blocks are arranged in the arc-shaped slotted holes to limit the telescopic length range of the first support rods relative to the second support rods.

The left side and the right side of the front end of the front wheel frame are respectively provided with a front wheel frame rod, and the front wheel seats of the two front wheel sets are respectively pivoted at the bottom of the front end of the front wheel frame rod.

The handle comprises a holding cross rod with an operation component and two rod parts which are formed by bending and extending the left end and the right end of the holding cross rod downwards respectively, and the lower ends of the two rod parts are connected with two second joint components respectively.

An elastic strip is connected between the middle parts of the two rear foot rods.

Each rear wheel seat is provided with a wheel locking device capable of selectively locking the rear wheel, a steel cable is connected between the two wheel locking devices to link the two wheel locking devices to actuate, and one of the wheel locking devices is provided with a pedal capable of controlling the wheel locking devices to actuate.

The invention relates to a baby carriage frame, which mainly utilizes a rear wheel folding mechanism connected to the rear side of a frame body, wherein the rear wheel folding mechanism is symmetrically arranged on a first cross rod of the frame body in a bending and oblique way by two rear wheel frame components, and a rear foot rod of the rear wheel frame component is connected with a second cross rod of the frame body by a connecting rod group. On the other hand, the baby carriage frame forms a multi-point supporting mechanism which can be unfolded and folded by utilizing the seat cushion supporting mechanism which is connected to the bottom of the seat cushion plate, is arranged between the linkage shaft rod and the first cross rod and is provided with the folding function, so that stable auxiliary supporting force is provided for the seat cushion plate, the baby carriage is ensured to be unfolded and used in a stable and stretching state, and the baby carriage can walk on the ground stably.

When the baby carriage frame is folded, the rear wheel folding mechanism is folded through the bending of the connecting rod group, so that the rear foot rod is driven to be close towards the front wheel frame direction by taking the pivot connected with the rear foot rod as the rotation center, the rear wheel frame component is guided by the connecting rod group to be relatively close towards the middle direction of the carriage body in the forward folding process, and finally, the two rear wheels can be folded between the two front wheels, so that the whole width and the volume of the baby carriage frame are greatly reduced, and the problem that the occupied space of the width and the volume of the folded baby carriage frame is difficult to be reduced because the two rear wheels are respectively positioned at the outer sides of the two front wheels after the baby carriage frame is folded is solved. On the other hand, in the folding process of the baby carriage frame, under the driving of the first joint assemblies at the left side and the right side, the seat cushion supporting mechanism can be automatically folded by directly pulling the whole seat cushion supporting mechanism through the supporting plate by the linkage shaft rod positioned in the carriage body.

[ description of the drawings ]

The invention is described in further detail below with reference to the attached drawing figures, wherein:

fig. 1 is a schematic perspective view of a stroller frame according to the present invention.

FIG. 2 is a schematic diagram showing a second perspective view of a stroller frame according to the present invention.

Fig. 3 is a side view of the stroller frame of the present invention.

Fig. 4 is a partial bottom perspective view of the stroller frame of the present invention.

Fig. 5 is a bottom plan view of the stroller frame of the present invention.

Fig. 6 is a partially enlarged rear perspective view of the stroller frame according to the present invention.

Fig. 7 is a partial bottom plan view of a stroller frame according to the present invention.

FIG. 8 is a schematic side plan view of the stroller frame of the present invention in a collapsed state.

Fig. 9 is a schematic perspective view of the stroller frame according to the present invention in a folded state.

Fig. 10 is a plan view schematically showing a stroller frame according to the present invention in a folded state.

[ detailed description ] of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 3 and 5, a preferred embodiment of the stroller frame of the present invention comprises a frame body 1, two front wheel sets 2, a seat cushion supporting mechanism 3 and a rear wheel folding mechanism 4.

As shown in fig. 1 to 5, the frame body 1 includes a front wheel frame 10, a seat cushion supporting frame 11, two first joint components 12A, two push rods 13, two second joint components 12B, a seat pad 111, a handle 14, a first cross bar 16, a second cross bar 17 and a linkage shaft 121, the front wheel frame 10 includes two front foot rods 101 which are opposite from each other in left and right directions and extend obliquely from front to rear upwards, each of the left and right sides of the front end of the front wheel frame 10 has a front wheel frame rod 102, the seat cushion supporting frame 11 is assembled on the two front foot rods 101 through the two first joint components 12A, the lower ends of the two push rods 13 are respectively connected with the two first joint components 12A, and the two second joint components 12B are respectively connected with the upper ends of the two push rods 13. The seat cushion plate 111 is disposed on the seat cushion supporting frame 11, the handle 14 includes a holding cross bar 141, and two rod portions 142 formed by bending and extending from the left and right ends of the holding cross bar 141, wherein the two rod portions 142 are respectively connected to the two second joint assemblies 12B, and an operation assembly 15 is disposed in the holding cross bar 141 to control the corresponding actions of the first joint assemblies 12A and the second joint assemblies 12B.

In the frame body 1, the first joint component 12A and the second joint component 12B have clutch control and rotation functions and are controlled by the operation component 15, so that the frame body 1 can be folded, folded and unfolded for positioning, and the first joint component 12A, the second joint component 12B and the operation component 15 are not part of the invention, and can be selected from various known joint structures, and detailed structures thereof are not repeated herein.

In the frame body 1, as shown in fig. 1 to 5, the first rail 16 and the second rail 17 are disposed below the seat support frame 11, wherein the first rail 16 is laterally connected between the two first joint assemblies 12A. The second cross bar 17 is disposed in parallel to the front lower side of the first cross bar 16, and the second cross bar 17 is connected between the left and right front foot bars 101 of the front wheel frame 10. The linkage shaft 121 is disposed below the rear portion of the bottom surface of the seat cushion 111, and is connected between the two first joint assemblies 12A, and is linked with the first joint assemblies 12A.

As shown in fig. 1, 3, 4 and 5, the frame body 1 is connected with a telescopic support rod set 18 between the push rod 13 and the seat cushion support frame 11 at the left and right sides, the telescopic support rod set 18 includes a first support rod 181 and a second support rod 182, the first support rod 181 and the second support rod 182 are arc-shaped rods, one end of the first support rod 181 is pivotally connected with the push rod 13, an arc-shaped slot 1811 is formed on a side surface of the first support rod 181, one end of the second support rod 182 is pivotally connected to a side edge of the seat cushion support frame 11, the other end of the second support rod 182 is movably connected to the other end of the first support rod 181, and a limiting block 1821 is disposed at the other end of the second support rod 182, and the limiting block 1821 is disposed in the arc-shaped slot 1811 to limit a length range of the relative expansion of the first support rod 181 and the second support rod 182.

As shown in fig. 1, 3, 4 and 5, two front wheel sets 2 are respectively pivoted on the left and right sides of the front end of the front wheel frame 10, each front wheel set 2 includes a front wheel seat 20 and a front wheel 21 pivoted on the front wheel seat 20, and the front wheel seat 20 is pivoted on the bottom of the front end of the front wheel frame bar 102 to control or change the traveling direction of the front wheel 21.

As shown in fig. 1, 3, 4 and 5, the seat cushion supporting mechanism 3 is movably disposed in the frame body 1, and the seat cushion supporting mechanism 3 is connected to the bottom of the seat cushion plate 111 and located between the first rail 16 and the second rail 17, the seat cushion supporting mechanism 3 includes a first arc plate 31, a second arc plate 32 and a supporting plate 33, the upper end of the first arc plate 31 is pivoted to the middle of the bottom surface of the seat cushion plate 111, the lower end of the second arc plate 32 is pivoted to the second rail 17, the upper end of the supporting plate 33 is connected with the linkage shaft 121, the lower end of the first arc plate 31, the upper end of the second arc plate 32 and the lower end of the supporting plate 33 are coaxially pivoted by a pivot 34, and a limit stop 311 is disposed at the lower end of the first arc plate 31 and below the pivot 34 and outside the upper end of the second arc plate 32, so as to form a foldable multi-point supporting mechanism.

As shown in fig. 2, 3, 5 and 6, the rear wheel folding mechanism 4 is disposed at the rear side of the frame body 1 and behind the left and right front wheels 21 relative to the front end of the frame body 1, and the rear wheel folding mechanism 4 includes two rear wheel frame assemblies 40 and two link groups 50.

As shown in fig. 2, 3, 5 and 6, two rear wheel frame assemblies 40 are movably disposed at the rear side of the frame body 1, each rear wheel frame assembly 40 includes a rear wheel 41, a rear wheel seat 42, a rear foot bar 43 and a connection seat 44, the rear wheel 41 has an axle, the rear wheel 41 is pivotally disposed at one side of the rear wheel seat 42 through the axle, the lower end of the rear foot bar 43 is fixedly connected with the top of the rear wheel seat 42, an included angle formed by the central axis of the rear foot bar 43 and the central axis of the axle of the rear wheel 41 is an acute angle, the connection seat 44 is pivotally connected to the upper end of the rear foot bar 43 and is obliquely fixed on the first cross bar 16 of the frame body 1, the connection seat 44 includes a pivot portion 441, a fixing portion 442 and a stop portion 443, the pivot portion 441 of the connection seat 44 is pivotally connected to the upper end of the rear foot bar 43 through the pivot, and the stop portion 443 is located at the rear end of the rear foot bar 43 and can limit the angle of the rear foot bar 43 relative to the connection seat 44. The connecting seat 44 of the two rear wheel frame assemblies 40 is inclined from top to bottom (to left and right, and outside) and is located between the two second joint assemblies 12B of the frame body 1, and the two rear foot rods 43 form a splayed structure through the connecting seat 44 arranged obliquely, that is, the two rear foot rods 43 are inclined from top to bottom from front to back and gradually from top to bottom and are symmetrical. When the two rear wheel frame assemblies 40 are in the unfolded state, the rear foot bars 43 of the two rear wheel frame assemblies 40 extend from the upper part of the front end to the lower part of the rear end, and the distance between the upper ends of the two rear foot bars 43 is smaller than the distance between the lower ends of the two rear foot bars 43, and the distance between the two rear wheels 41 is larger than the distance between the two front wheels 21. When the two rear wheel frame assemblies 40 are in the folded state, the distance between the two rear wheels 41 is smaller than the distance between the two front wheels 21, and the two rear wheels 41 are arranged between the inner sides of the two front wheels 21.

As shown in fig. 2, 3, 5 and 6, an elastic strip 45 is connected between the middle parts of the two rear foot rods 43 of the two rear wheel frame assemblies 40, the elastic strip 45 can be made of spring steel sheets, and the range of the two rear foot rods 43 after being stretched is limited by the elastic strip 45. The rear wheel seat 42 of the two rear wheel frame components 40 can be further provided with wheel locking devices 60, a flexible steel cable 62 can be connected between the two wheel locking devices 60, a pedal 61 is arranged on one of the wheel locking devices 60, the wheel locking devices 60 are controlled by the pedal 61, and the wheel locking devices 60 respectively arranged in the two rear wheel seats 42 are linked by the steel cable 62. The wheel locking device is not an inventive part of the present invention, and various known wheel locking devices can be used, and detailed structures thereof are not described herein.

As shown in fig. 2, 3, 5 and 6, the two link groups 50 are respectively disposed at two ends of the second cross bar 17 of the frame body and located at the outer sides of the rear foot bars 43 of the two rear wheel frame assemblies 40 to connect the corresponding rear foot bars 43, each link group 50 includes a first link 51, a second link 52, a first multi-directional connecting piece 53 and a second multi-directional connecting piece 54, one end of the first link 51 is connected to the second cross bar 17, the other end of the first link 51 is connected to one end of the second link 52 through the first multi-directional connecting piece 53, the other end of the second link 52 is connected to the middle part of the rear foot bar 43 through the second multi-directional connecting piece 54, and the two rear wheel frame assemblies 40 can be unfolded and folded back, forward and left and right relatively relative to the frame body 1 by using the first multi-directional connecting piece 53 connected between the first link 51 and the second link 52 and the second multi-directional connecting piece 54 connected between the second link 52 and the rear foot bar 43.

Regarding the working principle of the stroller frame of the present invention, as shown in fig. 1 to 3, when the stroller frame is unfolded, the left and right push rods 13 of the frame body 1 are respectively extended upwards through the first joint assemblies 12A, the handles 14 are respectively extended upwards through the second joint assemblies 12B, the telescopic support rod assemblies 18 on the left and right sides are respectively extended, and the seat support frame 11 provides stable supporting force for the seat cushion plate 111, so that the frame body 1 is in a stable unfolded state.

As shown in fig. 1 to 6, the rear wheel folding mechanism 4 is located at the rear side of the frame body 1, two rear wheel frame assemblies 40 in the rear wheel folding mechanism 4 extend rearward, the rear foot bar 43 is guided to extend rearward and outward by the connecting seats 44 provided at the outer sides of the two rear wheel frame assemblies 40 in a slanting manner, the distance between the two rear wheels 41 is further made to be larger than the distance between the two front wheels 21, and simultaneously, the rear foot bar 43 extending rearward is provided with supporting force by using the link groups 50 respectively connected between the two ends of the second cross bar 17 and the middle part of the rear foot bar 43, and each rear wheel frame assembly 40 abuts against the upper part of the rear foot bar 43 by the stop 443 at the rear side of the lower end of the connecting seat 44.

In addition, the stroller frame also utilizes the foldable seat cushion supporting mechanism to form a multi-point supporting mechanism capable of being unfolded and folded on the bottom of the seat cushion plate 111, and provides stable auxiliary supporting force for the seat cushion plate 111. The rear wheel folding mechanism 4 is in a stable extending state when the baby carriage frame is unfolded, so that the baby carriage frame can be stably and safely pushed to walk on the ground.

As shown in fig. 8 to 10, when the stroller frame is folded, the first joint assembly 12A and the second joint assembly 12B are switched to the unlocked state by the operation assembly 15 on the handle 14, so that the stroller frame can be folded, the two first joint assemblies 12A bend the two push rods 13 of the stroller frame body 1 forward and close to the two front legs 101 of the front wheel frame 10, and the two second joint assemblies 12B bend the handle 14 reversely and close to the two push rods 13, so that the seat cushion supporting mechanism 3 can be folded automatically by pulling the whole seat cushion supporting mechanism 3 through the supporting plate 33 under the driving of the first joint assemblies 12A on the left and right sides of the linkage shaft 121 in the stroller frame body 1, and the first arc plate 31, the second arc plate 32 and the supporting plate 33 of the seat cushion supporting mechanism 3 are folded in the stroller frame body 1.

On the other hand, the rear wheel folding mechanism 4 is folded by bending the two connecting rod sets 50, so as to drive the rear foot rods 43 to be folded in the forward direction of the front wheel frame 10 by taking the pivot in the pivot joint 441 of the connecting seat 44 as the rotation center, and the two connecting rod sets 50 are utilized to greatly reduce the overall width and the volume of the stroller frame after folding, thereby realizing the volume minimization and convenient people travel carrying and storage by using the first multi-directional connecting piece 53 connected between the first connecting rod 51 and the second connecting rod 52 and the second multi-directional connecting piece 54 connected between the rear foot rods 43, so that the two rear wheel frame assembly 40 is folded forward, and simultaneously, the left rear foot rod 43 and the right rear foot rod 43 are guided to be relatively close towards the middle direction of the frame body 1.

Claims

1. A stroller frame comprising:

a frame body (1), wherein the frame body (1) comprises a front wheel frame (10), a seat cushion supporting frame (11), two first joint components (12A), two push rods (13), two second joint components (12B), a handle (14), a first cross rod (16), a second cross rod (17) and a linkage shaft lever (121);

the front wheel frame (10) comprises two front foot rods (101) which are opposite in left and right and extend obliquely from front to back upwards, two first joint assemblies (12A) are respectively arranged between a seat cushion support frame (11) and the two front foot rods (101), seat cushion plates (111) are arranged on the seat cushion support frame (11), the lower ends of two push rods (13) are respectively connected with the two first joint assemblies (12A), the upper ends of the two push rods (13) are respectively connected with two second joint assemblies (12B), two ends of a handle (14) are respectively connected with the two second joint assemblies (12B), an operation assembly (15) is arranged on the handle (14) to control the corresponding operation of the first joint assemblies (12A) and the second joint assemblies (12B), the first cross rods (16) and the second cross rods (17) are arranged below the seat cushion support frame (11), the second cross rods (17) are arranged on the front lower sides of the first cross rods (16) in parallel, the two ends of the first cross rods (16) are respectively connected with the two second joint assemblies (12B), two ends of each handle (14) are respectively connected with the two second joint assemblies (12A), and the two end faces of each second cross rods (17) are connected with the front foot rods (12A) in parallel to each other, and the two end faces of each other are connected with the two end faces of the corresponding to the corresponding operation rod (12A;

the two front wheel sets (2), the two front wheel sets (2) are respectively pivoted on the left side and the right side of the front end of the frame body (1), the front wheel sets (2) comprise a front wheel seat (20) and a front wheel (21) pivoted on the front wheel seat (20), and the front wheel seat (20) is connected with the lower end of a front foot rod (101);

the seat cushion supporting mechanism (3), the seat cushion supporting mechanism (3) can be movably assembled below the seat cushion plate (111), the seat cushion supporting mechanism (3) comprises a first arc-shaped plate (31), a second arc-shaped plate (32) and a supporting plate (33), the upper end of the first arc-shaped plate (31) is pivoted at the middle part of the bottom surface of the seat cushion plate (111), the lower end of the second arc-shaped plate (32) is pivoted at the second cross rod (17), the upper end of the supporting plate (33) is connected with the linkage shaft rod (121), and the lower ends of the first arc-shaped plate (31), the upper end of the second arc-shaped plate (32) and the lower end of the supporting plate (33) are coaxially pivoted;

the rear wheel folding mechanism (4) is arranged at the rear side of the frame body (1), and the rear wheel folding mechanism (4) comprises two rear wheel frame components (40) and two connecting rod groups (50);

the two rear wheel frame components (40) are movably assembled on the first cross bar (16), each rear wheel frame component (40) comprises a rear wheel (41), a rear wheel seat (42), a rear foot rod (43) and a connecting seat (44), the rear wheel (41) is pivoted on one side of the rear wheel seat (42) through a wheel shaft, the lower end of the rear foot rod (43) is connected with the top of the rear wheel seat (42), an included angle formed by the rear foot rod (43) and the wheel shaft of the rear wheel (41) is an acute angle, the connecting seat (44) is obliquely fixed on the first cross bar (16), the upper end of the rear foot rod (43) is pivoted on the connecting seat (44), the connecting seat (44) comprises a pivoting part (441) and a fixing part (442) positioned at the upper end of the pivoting part (441) and a stopping part (443) positioned at the lower end of the pivoting part (441), the connecting seat (44) is fixedly connected with the top of the first cross bar (16) through the fixing part (442), the connecting seat (44) is pivoted on the upper end of the rear foot rod (43) relative to the pivoting part (43) in a limited manner, the connecting seat (44) of the two rear wheel frame components (40) is inclined from top to bottom and outwards so that the two rear foot rods (43) form an involute inclined from the upper part of the front end to the lower part of the rear end and are symmetrical, when the rear wheel frame components are unfolded, the distance between the two rear wheels (41) is larger than the distance between the two front wheels (21), and when the rear wheel frame components are folded, the two rear wheels (41) are arranged at the position between the two front wheels (21);

each connecting rod group (50) comprises a first connecting rod (51) and a second connecting rod (52), one end of the first connecting rod (51) is connected to the second cross rod (17), the other end of the first connecting rod (51) is connected with one end of the second connecting rod (52) through a first multidirectional connecting piece (53), and the other end of the second connecting rod (52) is connected to the middle of the rear foot rod (43) through a second multidirectional connecting piece (54).

2. The stroller frame according to claim 1, characterized in that a limit stop (311) is provided on the bottom end of the first arcuate plate (31) below the pivot post (34) and outside the top end of the second arcuate plate (32).

3. The stroller frame according to claim 1, characterized in that the two link groups (50) are respectively arranged at two ends of the second cross bar (17) and are positioned outside the rear foot bar (43) to be connected with the middle parts of the corresponding rear foot bars (43).

4. The stroller frame according to claim 1, wherein a telescopic support bar set (18) is respectively connected between the push bars (13) and the seat cushion support frame (11) at the left and right sides of the frame body (1), each telescopic support bar set (18) comprises a first support bar (181) and a second support bar (182), the first support bar (181) and the second support bar (182) are arc-shaped bars, one end of the first support bar (181) is pivoted on the push bars (13), the side surface of the first support bar (181) is provided with an arc-shaped slot hole (1811), one end of the second support bar (182) is pivoted on the side edge of the seat cushion support frame (11), the other end of the second support bar (182) is movably connected with the other end of the first support bar (181), the other end of the second support bar (182) is provided with a limiting block (1821), and the limiting block (1821) is arranged in the arc-shaped slot hole (1811) to limit the telescopic length range of the first support bar (181) relative to the second support bar (182).

5. A stroller frame according to claim 3, wherein the front wheel frame (10) has a front wheel frame bar (102) on each of the left and right sides of the front end, and the front wheel seats (20) of the two front wheel sets (2) are respectively pivoted to the bottom of the front ends of the front wheel frame bars (102).

6. The stroller frame according to claim 1, wherein the handle (14) comprises a holding cross bar (141) having an operating component (15) and two bar portions (142) formed by bending and extending downwards from the left and right ends of the holding cross bar (141), and the lower ends of the two bar portions (142) are respectively connected to the two second joint components (12B).

7. A stroller frame according to any of the claims 1-6, characterized in that an elastic strip (45) is connected between the middle parts of the two rear foot bars (43).

8. The stroller frame according to claim 7, wherein each of the rear wheel seats (42) is provided with a wheel locking device (60) capable of selectively locking the rear wheel (41), a wire rope (62) is connected between the two wheel locking devices (60) to link the two wheel locking devices (60) for actuation, and wherein one of the wheel locking devices (60) is provided with a pedal (61) capable of controlling the actuation of the wheel locking device (60).