Side door opening and closing mechanism of automatic dumping car

Abstract

The invention provides a self-dumping car side door opening and closing mechanism, and relates to the technical field of self-dumping cars, the self-dumping car side door opening and closing mechanism comprises a first connecting rod mechanism, the first connecting rod mechanism comprises a first connecting rod, a second connecting rod and a third connecting rod of which one ends are hinged together, and the other end of the first connecting rod is hinged to a first hinge of a first side door of a carriage; the other end of the second connecting rod is hinged to a bottom beam, and the other end of the third connecting rod is hinged to a bottom frame of a carriage. The first connecting rod mechanism is used for achieving transmission between the compartment and the first side door, so that the first side door is driven to be opened when the compartment turns over towards the side where the first side door is located. The opening and closing mechanism of the whole first side door is composed of a plurality of connecting rods and is simple in structure and easy to assemble. And the rod piece is light in self weight and easy to produce and manufacture, the self weight of the door opening and closing mechanism of the automatic dumping car can be effectively reduced, and manufacturing and maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of self-rolling vehicles, and in particular to a side door opening and closing mechanism of a self-rolling vehicle. Background Art

[0002] A self-tipping vehicle is a railway vehicle for transporting bulk goods. It has the functions of self-tipping on both sides and automatic opening and closing of doors, which can save manpower and reduce labor intensity. At present, for the overturning mechanism of self-tipping vehicles with large load and volume, some adopt Figure 1 The large folding mechanism shown in the figure includes a restraining elbow 51, a spring 52, a support 53 and other structures, which has a relatively complex structure and high assembly requirements. In addition, the restraining elbow 51 is large in size and is usually a casting, which results in a larger size and weight of the entire tipping mechanism, and a higher manufacturing and maintenance cost. Summary of the invention

[0003] The problem solved by the invention is to design a self-turning vehicle side door opening and closing mechanism with light deadweight and low manufacturing and maintenance costs.

[0004] To solve the above-mentioned problem, the present invention provides a self-flipping side door opening and closing mechanism, including a first link mechanism, the first link mechanism including a first link, a second link and a third link hinged together at one end, the other end of the first link is hinged on the first hinge of the first side door of the car, the other end of the second link is hinged on the bottom beam, and the other end of the third link is hinged on the bottom frame of the car; the first link mechanism is used to realize the transmission between the car and the first side door, so that when the car flips to the side where the first side door is located, the first side door is driven to open.

[0005] Optionally, the common hinged end of the second connecting rod is higher than the other end, and the common hinged end is located on a side of the other end close to the first side door.

[0006] Optionally, the common hinged end of the third connecting rod is lower than the other end, and the common hinged end is located on a side of the other end close to the first side door.

[0007] Optionally, the second connecting rod and the third connecting rod are arranged in a V shape, and the top angle of the V shape is an acute angle.

[0008] Optionally, two ends of the first connecting rod are respectively located on two sides of the first side door, and the non-common hinged end is located at the bottom of the first side door.

[0009] Optionally, the main body of the first hinge extends obliquely downward from the bottom edge of the first side door, and the end portion is hinged to the first connecting rod.

[0010] Optionally, a plurality of the first link mechanisms are arranged at intervals along the length direction of the carriage.

[0011] Optionally, the axis of the hinge point of the second connecting rod on the bottom beam coincides with the first axis, wherein the first axis is the flipping centerline when the car body flips to the opposite side of the first side door.

[0012] Optionally, the first connecting rod, the second connecting rod and / or the third connecting rod are length-adjustable rods.

[0013] Optionally, the self-flipping side door opening and closing mechanism also includes a second link mechanism, the second link mechanism includes a fourth link, a fifth link and a sixth link hinged together at one end, the other end of the fourth link is hinged to the second hinge of the second side door of the car, the other end of the fifth link is hinged to the bottom beam, and the other end of the sixth link is hinged to the base frame of the car; the second link mechanism is used for transmission between the car and the first side door, so that when the car flips to the side where the second side door is located, the second side door is driven to open.

[0014] The beneficial effects of the self-flipping vehicle side door opening and closing mechanism of the present invention are as follows: the opening and closing mechanism of the entire first side door is composed of a plurality of connecting rods, which has a simple structure and is easy to assemble; and the rods themselves are light in weight and easy to manufacture, which can effectively reduce the self-weight of the self-flipping vehicle door opening and closing mechanism and reduce manufacturing and maintenance costs. In addition, the kinematic pair in the connecting rod mechanism is generally a low pair, with a large surface contact pressure and a strong bearing capacity, and is easy to lubricate, which reduces wear, improves durability, and reduces the occurrence of self-flipping vehicle door opening failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a large folding mechanism in the background technology.

[0016] Figure 2 It is a schematic diagram of a cross-section of a compartment in the upright position of the self-rolling vehicle side door opening and closing mechanism of the present invention.

[0017] Figure 3 It is a schematic cross-sectional view of the right side flip of the vehicle compartment of the self-flipping vehicle side door opening and closing mechanism of the present invention.

[0018] Figure 4 It is a schematic diagram of the cross-section of the left side flip of the vehicle compartment of the self-flipping vehicle side door opening and closing mechanism of the present invention.

[0019] Figure 5 The diagram is a schematic diagram of the carriage upright position of the self-rolling vehicle side door opening and closing mechanism of the present invention.

[0020] Figure 6 It is a schematic diagram of the right side rollover of the vehicle compartment of the self-rollover side door opening and closing mechanism of the present invention.

[0021] Figure 7 It is a schematic diagram of the left side rollover of the vehicle compartment of the self-rollover side door opening and closing mechanism of the present invention.

[0022] Description of reference numerals:

[0023] 1. First connecting rod mechanism; 11. First connecting rod; 12. Second connecting rod; 13. Third connecting rod; 21. First side door; 211. First hinge; 22. Base frame; 23. Second side door; 231. Second hinge; 3. Second connecting rod mechanism; 31. Fourth connecting rod; 32. Fifth connecting rod; 33. Sixth connecting rod; 4. Bottom beam; 51. Restraining elbow; 52. Spring; 53. Support; 61. Cylinder; 621. Rotating shaft seat; 622. Rotating shaft section. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0025] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0026] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0027] like Figure 2-7 As shown, an embodiment of the present invention provides a self-flipping side door opening and closing mechanism, including a first link mechanism 1, the first link mechanism 1 includes a first link 11, a second link 12 and a third link 13, the other end of the first link 11 is hinged on the first hinge 211 of the first side door 21 of the car, the other end of the second link 12 is hinged on the bottom beam 4, and the other end of the third link 13 is hinged on the bottom frame 22 of the car; the first link mechanism 1 is used to realize the transmission between the car and the first side door 21, so that when the car flips to the side where the first side door 21 is located, the first side door 21 is driven to open.

[0028] It should be noted that the first link mechanism 1 is a planar link mechanism, that is, the first link 11, the second link 12 and the third link 13 all move within a certain cross section of the carriage. There is a side door on each side of the carriage, namely, the first side door 21 and the second side door 23. In this embodiment, the first side door 21 is an example of a right door; the bottom edges of the first side door 21 and the second side door 23 are both rotatably arranged on the carriage; the carriage is a self-turning structure, which can rotate around two axes respectively, and correspondingly realizes tipping to both sides.

[0029] For the convenience of description, in the motion plane of the first link mechanism 1, as Figure 2 As shown, the rotation axes of the first side door 21 and the second side door 23 on the car body correspond to points P and Q; the two axes of the car body tilting correspond to points M and N. The first connecting rod 11, the second connecting rod 12 and the third connecting rod 13 are connected to the hinge point B, and the hinge point B is a movable hinge point, which means that the position of the rotation axis at the connection point can be changed; the other end of the first connecting rod 11 is connected to the end of the first hinge 211 of the first side door 21 at the hinge point C; the other end of the third connecting rod 13 is connected to the bottom frame 22 of the car body at the hinge point A; the other end of the second connecting rod 12 is hinged to the bottom beam 4, and it will be mentioned later that the better way is to hinge to the point M.

[0030] In the above-mentioned self-flipping side door opening and closing mechanism, the first link mechanism 1 is arranged under the car body, specifically between the bottom frame 22 and the bottom beam 4 of the car body, and the flipping action of the car body toward the first side door 21 is mechanically linked with the opening and closing action of the first side door 21. As the car body flips, the first side door 21 gradually opens, and as the car body resets, the first side door 21 gradually closes. The specific mechanical linkage process is as follows:

[0031] ① When the carriage tilts to the right side in the direction of the first side door 21, that is, the carriage rotates rightward around the second rotation axis where the rotation center N is located, the distance between the two points MA increases, driving the hinge point B to move to the left, thereby pulling the first connecting rod 11 to move to the left relative to the carriage, and then pulling the first side door 21 to rotate clockwise around the hinge point P through the hinge point C, so that the first side door 21 is opened, and finally forms a continuous surface with the floor of the carriage, as shown in FIG. Figure 3 As shown, the goods are completely unloaded; during this process, since the relative distance between the two points NE does not change, the relative positions of the rods of the second connecting rod mechanism 3 do not change either, so the second side door 23 always remains closed.

[0032] ② When the carriage returns to its original position, the relative distance between MA becomes smaller, driving the hinge point B to move to the right, thereby pushing the first connecting rod 11 to move to the right relative to the carriage, and pushing the first side door 21 to rotate counterclockwise around the hinge point P through the hinge point C, so that the first side door 21 is closed and finally returns to the adjacent position. Figure 2 position shown and maintain it.

[0033] Compared with the prior art, the opening and closing mechanism of the entire first side door 21 is composed of multiple connecting rods, which has a simple structure and is easy to assemble; and the rod itself is light in weight and easy to manufacture, which can effectively reduce the weight of the self-turning vehicle door opening and closing mechanism and reduce manufacturing and maintenance costs. In addition, the kinematic pair in the connecting rod mechanism is generally a low pair, with a large surface contact pressure and a strong bearing capacity, and is easy to lubricate, which reduces wear, improves durability, and reduces the occurrence of self-turning vehicle door opening failures.

[0034] Optionally, the common hinged end of the second connecting rod 12 is higher than the other end, and the common hinged end is located on a side of the other end close to the first side door 21 .

[0035] The common hinge end of the second link 12, i.e., the end at point B, is movable, and the hinge point at the other end hinged on the bottom beam 4 is fixed. Therefore, when the second link 12 is linked with the right flipping of the carriage, the movement generated is the rotation of the rod body around the other end. Therefore, when the carriage is in the upright position, Figure 2 As shown, the common hinge end of the second connecting rod 12 is higher than the other end, and the common hinge end is located on the side of the other end close to the first side door 21, which is conducive to driving the common hinge point B to move to the left when the car body is flipped to the right, thereby realizing the opening of the first side door 21.

[0036] Optionally, the common hinged end of the third connecting rod 13 is lower than the other end, and the common hinged end is located at a side of the other end close to the first side door 21 .

[0037] The other end of the third link 13 is connected to the base frame 22 of the car. When the car flips to the right, the other end of the third link 13 rotates and moves upward. Therefore, the common hinge end of the third link 13 is arranged to be lower than the other end, and the common hinge end is located on the side of the other end close to the first side door 21, which can ensure that the flipping of the car to the right drives the common hinge point B to move to the left, thereby realizing the opening of the first side door 21.

[0038] In this embodiment, the second connecting rod 12 and the third connecting rod 13 are arranged in a V shape, and the top angle of the V shape is an acute angle. Figure 2 As shown, when the carriage flips to the right, the V-shaped structural opening formed by the rod bodies of the second connecting rod 12 and the third connecting rod 13 gradually opens, the structural design is ingenious, and the transmission is stable and reliable.

[0039] In addition, if Figure 3 As shown, it can be designed that after the car body is tilted to the right, the second connecting rod 12 and the third connecting rod 13 are still arranged in a V shape, and the opening direction remains unchanged, still facing the second side door 23. Figure 2 As shown, the specific hinged position of the other end of the third connecting rod 13 on the base frame 22 can be designed to be located between the two ends of the third connecting rod 13 in the width direction of the carriage.

[0040] Optionally, two ends of the first connecting rod 11 are respectively located on two sides of the first side door 21 , and the non-common hinged end is located at the bottom of the first side door 21 .

[0041] like Figure 2 As shown, the non-public hinged end of the first connecting rod 11, i.e., the end where point P is located, extends out of the bottom of the carriage and is arranged on the outside of the first side door 21, having a larger adjustable range of movement, which facilitates opening of the first side door 21.

[0042] In this embodiment, the main body of the first hinge 211 extends obliquely downward from the bottom edge of the first side door 21, and the end is hinged to the first connecting rod 11. The bottom edge of the first side door 21 is hinged on the carriage, and a part of the bottom edge extends obliquely downward to form the first hinge 211. Figure 5-7 As shown, the first hinge 211 is fixed integrally with the first side door 21 to form a force arm for the first link mechanism 1 to drive the first side door 21 to rotate and open.

[0043] Alternatively, if Figure 4-7 As shown, a plurality of first link mechanisms 1 are arranged at intervals along the length direction of the carriage. The torque that a single first link mechanism 1 can provide is limited, so a plurality of first link mechanisms 1 can be evenly spaced along the length direction to evenly distribute the torque for rotating the first side door 21 or the torque for keeping the first side door 21 closed, so that the forces on each component during the operation of the entire opening and closing mechanism are more reasonable.

[0044] Optionally, the axis of the hinge point of the second connecting rod 12 on the bottom beam 4 coincides with the first axis, wherein the first axis is the flipping centerline when the vehicle compartment flips to the opposite side of the first side door 21 .

[0045] In the motion plane of the first linkage mechanism 1, as Figure 2-4 As shown, the point corresponding to the first axis is point M. The first axis is the flipping centerline when the car body rolls over to the opposite side of the first side door 21. The left end rotation axis of the second connecting rod 12 coincides with the first axis, so that the entire first connecting rod mechanism 1 is reasonably arranged in the width direction of the car body, and has better transmission and force effects.

[0046] Optionally, the first connecting rod 11, the second connecting rod 12 and / or the third connecting rod 13 are length-adjustable rods.

[0047] By designing the rod of the first connecting rod mechanism 1 to be adjustable in length, when the door is opened to the side where the first side door 21 is located, the opening speed of the first side door 21 can be adjusted by adjusting the length of one or more rods to adapt to the actual loading situation and meet the requirements of tipping stability; in addition, it is also possible to achieve automatic door opening without the car body tipping over, thereby realizing the functions of early door opening and early unloading.

[0048] Optionally, only the length of the first connecting rod 11 is adjustable, and when the door is opened toward the side where the first side door 21 is located, the length of the first connecting rod 11 is extended synchronously, so that the opening speed of the first side door 21 can be slowed down or even prevented from being opened, and vice versa, the length of the first connecting rod 11 is shortened synchronously, so that the opening speed of the first side door 21 can be accelerated. Of course, how to adjust the length of the first connecting rod 11 and how much to adjust it need to be designed and calculated according to actual conditions.

[0049] Optionally, the self-flipping side door opening and closing mechanism also includes a second link mechanism 3, the second link mechanism 3 includes a fourth link 31, a fifth link 32 and a sixth link 33 which are hinged together at one end, the other end of the fourth link 31 is hinged on the second hinge 231 of the second side door 23 of the car, the other end of the fifth link 32 is hinged on the bottom beam 4, and the other end of the sixth link 33 is hinged on the base frame 22 of the car; the second link mechanism 3 is used for transmission between the car and the first side door 21, so that when the car flips to the side where the second side door 23 is located, the second side door 23 is driven to open.

[0050] The second link mechanism 3 is similar in structure and working principle to the first link mechanism 1, except that the driving control object of the second link mechanism 3 is the second side door 23, so the structure needs to be adaptively adjusted. It should be noted that the second link mechanism 3 is also a planar link mechanism, that is, the fourth link 31, the fifth link 32 and the sixth link 33 all move within a certain cross section of the carriage.

[0051] like Figure 2 As shown, in the motion plane of the second link mechanism 3, the fourth link 31, the fifth link 32 and the sixth link 33 are commonly connected at the hinge point F, and the hinge point F is a movable hinge point, and the movable hinge point refers to a connection point at which the position of the rotation axis can be changed; the other end of the fourth link 31, i.e. the left end, is connected to the end of the second hinge 231 of the second side door 23 at the hinge point G; the other end of the sixth link 33, i.e. the right end, is connected to the base frame 22 of the car at the hinge point E; the other end of the fifth link 32, i.e. the right end, is hinged to the bottom beam 4, and it will be mentioned later that the better way is to be hinged at point N.

[0052] In the above-mentioned self-flipping side door opening and closing mechanism, the second link mechanism 3 is arranged between the bottom frame 22 and the bottom beam 4 of the carriage, and the flipping action of the carriage toward the second side door 23 is mechanically linked with the opening and closing action of the second side door 23. As the carriage flips, the second side door 23 gradually opens, and as the carriage resets, the second side door 23 gradually closes. The specific mechanical linkage process is as follows:

[0053] ① When the carriage tilts around the first axis toward the direction of the second side door 23, i.e., the left side, that is, the carriage rotates to the left around the axis where the rotation center M is located, the relative distance between the two points NE increases, driving the hinge point F to move to the right, thereby pulling the fourth connecting rod 31 to move to the right relative to the carriage, and then pulling the second side door 23 to rotate counterclockwise around the hinge point G through the hinge point G, so that the second side door 23 is opened, and finally forms a continuous surface with the floor of the carriage, as shown in FIG. Figure 4 As shown, the goods are completely unloaded; during this process, since the relative distance between MA does not change, the relative positions of the various rods of the first connecting rod mechanism 1 do not change either, so the first side door 21 always remains in a closed state.

[0054] ② When the carriage returns to its original position, the relative distance between points NE decreases, driving the hinge point F to move to the right, thereby pushing the fourth connecting rod 31 to move to the left relative to the carriage, and pushing the second side door 23 to rotate clockwise around the hinge point Q through the hinge point G, thereby closing the second side door 23 and finally returning to the adjacent position. Figure 2 position shown and maintain it.

[0055] In addition, a plurality of second link mechanisms 3 are also arranged at intervals along the length direction of the carriage, and it is noted that they are staggered with the first link mechanism 1, such as Figure 5-7 Moreover, if the arrangement of the rods of the second link mechanism 3 and the first link mechanism 1 is not staggered, they are symmetrical about the longitudinal center plane of the carriage, so the specific structure will not be described in detail.

[0056] There are various ways to realize the self-turning structure of the carriage, such as Figure 5-7 As shown, a structural example is given. A left-side pushing mechanism and a right-side rotating shaft assembly are arranged between the bottom frame 22 and the bottom beam 4. The left-side pushing mechanism and the right-side rotating shaft assembly cooperate to drive the carriage to flip around the second axis toward the side where the first side door 21 is located. Figure 5-7 As shown: the left-side pushing mechanism includes two oil cylinders 61, the cylinder bodies of the oil cylinders 61 are arranged on the bottom beam 4, and the piston rod ends of the oil cylinders 61 are arranged on the bottom frame 22; the right-side rotating shaft assembly includes two sets of mutually adapted and separable rotating shaft seats 621 and rotating shaft sections 622, the rotating shaft seats 621 are arranged on the bottom beam 4, and the rotating shaft sections 622 are arranged on the bottom frame 22. The rotating shaft sections 622 are all one-segment shaft structures, and the axes of the two rotating shaft sections 622 are collinear. The second axis is the turning center line when the carriage is turned over to the opposite side of the second side door 23. Figure 2 The corresponding point in is N, and when the carriage is not overturned, it contributes to the two rotating shaft segments 622.

[0057] Similarly, a right-side pushing mechanism and a left-side rotating shaft assembly are also arranged between the base frame 22 and the bottom beam 4. The right-side pushing mechanism and the left-side rotating shaft assembly cooperate to drive the car body to flip sideways around the first axis to the opposite side of the first side door 21; the specific structure is similar to the corresponding left-side pushing mechanism and the right-side rotating shaft assembly mentioned above, and will not be described in detail.

[0058] When in use, the carriage is in the upright position and is used for transportation, such as Figure 2 As shown, the doors on both sides, namely the first side door 21 and the second side door 23, are both self-locking; when the car body needs to roll over to the side where the first side door 21 is located and the first side door 21 is opened: the car body is driven to roll over to the side where the first side door 21 is located, and the first side door 21 is driven to open by the first connecting rod mechanism 1 during the rollover process, and the second side door is self-locking at this time; when the car body needs to roll over to the side where the second side door 23 is located and the second side door 23 is driven to open by the second connecting rod mechanism 3 during the rollover process, and the first side door is self-locking at this time; when the rollover is completed and needs to be reset, the car body is driven to flip and reset, the doors that are not opened remain self-locked, and the opened doors are naturally reset.

[0059] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A self-rolling vehicle side door opening and closing mechanism, characterized in that: The invention comprises a first link mechanism (1), wherein the first link mechanism (1) comprises a first link (11), a second link (12) and a third link (13) which are hinged together at one end, the other end of the first link (11) being hinged on a first hinge (211) of a first side door (21) of a carriage, the other end of the second link (12) being hinged on a bottom beam (4), and the other end of the third link (13) being hinged on a bottom frame (22) of the carriage; The first connecting rod mechanism (1) is used to realize transmission between the vehicle body and the first side door (21), so that when the vehicle body rolls over to the side where the first side door (21) is located, the first side door (21) is driven to open.

2. The self-rolling side door opening and closing mechanism according to claim 1, characterized in that: The common hinged end of the second connecting rod (12) is higher than the other end, and the common hinged end is located on a side of the other end close to the first side door (21).

3. The self-rolling side door opening and closing mechanism according to claim 2, characterized in that: The common hinged end of the third connecting rod (13) is lower than the other end, and the common hinged end is located on a side of the other end close to the first side door (21).

4. The self-rolling side door opening and closing mechanism according to claim 3, characterized in that: The second connecting rod (12) and the third connecting rod (13) are arranged in a V shape, and the top angle of the V shape is an acute angle.

5. The self-rolling side door opening and closing mechanism according to claim 2, characterized in that: The two ends of the first connecting rod (11) are respectively located on two sides of the plane where the first side door (21) is located, and the non-common hinged end is located at the bottom of the first side door (21).

6. The self-flipping side door opening and closing mechanism according to claim 5, characterized in that: The main body of the first hinge (211) extends obliquely downward from the bottom edge of the first side door (21), and the end portion is hinged to the first connecting rod (11).

7. The self-rolling side door opening and closing mechanism according to claim 1, characterized in that: A plurality of the first link mechanisms (1) are arranged at intervals along the length direction of the carriage.

8. The self-rolling side door opening and closing mechanism according to claim 1, characterized in that: The axis of the hinge point of the second connecting rod (12) on the bottom beam (4) coincides with the first axis, wherein the first axis is the turning center line when the carriage turns over to the opposite side of the first side door (21).

9. The self-rolling side door opening and closing mechanism according to claim 1, characterized in that: The first connecting rod (11), the second connecting rod (12) and / or the third connecting rod (13) are length-adjustable rods.

10. The self-rolling side door opening and closing mechanism according to claim 1, characterized in that: The vehicle further comprises a second link mechanism (3), the second link mechanism (3) having the same structure as the first link mechanism (1), comprising a fourth link (31), a fifth link (32) and a sixth link (33) hinged together at one end, the other end of the fourth link (31) being hinged to a second hinge (231) of a second side door (23) of the vehicle compartment, the other end of the fifth link (32) being hinged to a bottom beam (4), and the other end of the sixth link (33) being hinged to a bottom frame (22) of the vehicle compartment; The second connecting rod mechanism (3) is used for transmission between the carriage and the second side door (23), so that when the carriage rolls over to the side where the second side door (23) is located, the second side door (23) is driven to open.

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