CN116968615A - Roof lifting device for caravan - Google Patents

Abstract

The application discloses a lifting device for a motor home, and relates to the technical field of motor home. The lifting device for the caravan comprises a bottom plate, wherein a lifting driving piece is arranged on the bottom plate, and a top plate is arranged at the output end of the lifting driving piece; the lifting driving piece comprises a first cylinder body, a second cylinder body and a lifting rod which are sequentially arranged, one end of the second cylinder body is slidably arranged in the first cylinder body, and one end of the lifting rod is slidably arranged in the second cylinder body. The application enables the roof of the caravan to realize two-stage lifting.

Description

Roof lifting device for caravan

Technical Field

The application relates to the technical field of motor home, in particular to a motor home jacking device.

Background

The caravan is a special vehicle type, which can run on the road and can be used for people to live. With the development of the motor home industry at present, in order to meet diversified motor home living requirements and national regulated motor home specifications, the interior space of the motor home is required to reach a regulated size, so the height of the motor home is correspondingly designed to be higher and higher to increase the interior space, but the roofs of all motor home with higher heights are usually designed to be capable of lifting due to the limitation of the driving heights of various cities.

The prior art discloses a lift-off car as a house, and it includes the vehicle body, is equipped with electric lift jar on the vehicle body, is equipped with the roof that can move about on electric lift jar's the output, thereby drives electric lift jar and can drive the roof and rise and accomplish the lift-off of car as a house.

With respect to the related schemes in the above, the inventors consider that there are the following drawbacks: on the one hand, after the roof of the motor home rises, the motor home is inconvenient to travel through the height-limiting road section, and on the other hand, if the motor home does not rise, the space in the motor home is smaller and people cannot be accommodated.

Disclosure of Invention

In order to enable personnel to be contained in the caravan after the roof is lowered to meet the height limiting requirement, the application provides the caravan lifting device.

The application provides a roof lifting device for a motor home, which adopts the following technical scheme:

the lifting device for the caravan comprises a bottom plate, wherein a lifting driving piece is arranged on the bottom plate, and a top plate is arranged at the output end of the lifting driving piece;

the lifting driving piece comprises a first cylinder body, a second cylinder body and a lifting rod which are sequentially arranged, one end of the second cylinder body is arranged in the first cylinder body in a sliding mode, and one end of the lifting rod is arranged in the second cylinder body in a sliding mode;

the second cylinder body comprises a first piston positioned in the first cylinder body, the first piston divides the inner space of the first cylinder body into a first cavity and a second cavity, a first oil port and a second oil port are formed in the first cylinder body, the first oil port is communicated with the first cavity, and the second oil port is communicated with the second cavity;

the jacking rod comprises a second piston positioned in the second cylinder body, the second piston divides the inner space of the second cylinder body into a third cavity and a fourth cavity, a through hole is formed in the first piston, the third cavity is communicated with the first cavity through the through hole, a third oil port is formed in the second cylinder body, and the third oil port is communicated with the fourth cavity.

Through adopting above-mentioned technical scheme, can realize the second grade lift of roof, the action that specifically can realize is: the first oil port is used for oil feeding, the third oil port is used for oil discharging, oil entering the first cavity from the first oil port enters the third cavity through the through hole, and the oil pushes the second piston to move, so that the jacking rod drives the top plate to move, and the second cylinder body does not act at the moment; and then the third oil port stops oil discharge, the second oil port discharges oil, and the oil can push the first piston to move, so that the second cylinder body moves, and the jacking rod can drive the top plate to move again. The roof can be driven to carry out secondary lifting by the roof through the action, namely, the roof can be lowered by a part, so that people can be accommodated in the caravan after the height limiting requirement is met. The descending and ascending heights of the top plate can be flexibly adjusted by controlling the oil inlet and outlet of the first oil port, the second oil port and the third oil port,

preferably, the bottom plate is further provided with a mounting shell, the mounting shell is provided with a jacking piece, the output end of the jacking piece is provided with a first supporting mechanism and a second supporting mechanism, the first supporting mechanism is used for supporting the output end of the jacking piece, and the second supporting mechanism is used for supporting the top plate;

the first supporting mechanism comprises a guide assembly and a locking assembly, the guide assembly is arranged on the output end of the jacking piece, the guide assembly is used for guiding the moving direction of the output end of the jacking piece, the locking assembly is arranged in the installation shell, and the locking assembly is used for locking and supporting the output end of the jacking piece.

By adopting the technical scheme, after the lifting driving piece lifts the top plate, the lifting driving piece is driven to drive the first supporting mechanism and the second supporting mechanism to move, the first supporting mechanism can support the output end of the lifting piece, the second supporting mechanism arranged on the output end of the lifting piece can support the top plate, and the combination of the first supporting mechanism and the second supporting mechanism can increase the bearing capacity of the top plate as much as possible, so that the bearing capacity of the roof of a house is increased as much as possible; the guide assembly can guide the movement of the output end of the jacking piece, and the locking assembly can lock and support the guide assembly so as to lock and support the output end of the jacking piece.

Preferably, the guide assembly comprises a mounting seat, and the mounting seat is arranged on the output end of the jacking piece; the movable first support rod that is equipped with on the mount pad, the one end activity that the mount pad was kept away from to first support rod is equipped with the slider, it has the spout to open on the inner wall of installation casing, the slider card just can be followed the removal direction slip of jacking piece to the slider in the spout.

Through adopting above-mentioned technical scheme, when the output of jacking spare removes, the slider can slide in the spout and guide the output removal of jacking spare.

Preferably, the locking assembly comprises a mounting block, the mounting block is arranged on the mounting shell, a sliding hole is formed in the mounting block, a sliding rod is arranged in the sliding hole in a penetrating manner, and the sliding rod can slide along the moving direction of the jacking piece; the top of slide bar passes through the connecting block and links to each other with the slider, it has first fastener to articulate on the lateral wall that the slide bar is close to the bottom, the one end that the slide bar was kept away from to first fastener articulates there is the second fastener, the one end that the first fastener was kept away from to the second fastener is articulated to be connected with the installation piece.

Through adopting above-mentioned technical scheme, the slide bar that links to each other with the slider can remove under the drive of slider, and first fastener and the second fastener of mutual articulated this moment can inject the removal of slide bar.

Preferably, the sliding rod is driven by the sliding block to have a first limit position and a second limit position, and the first limit position is higher than the second limit position; when the sliding rod is in the first limit position, the second clamping piece can clamp the first clamping piece; when the sliding rod is in the second limit position, the second clamping piece can clamp the sliding rod.

By adopting the technical scheme, when the sliding rod is in the first limit position, the top plate is in a state of being jacked up by the lifting driving piece, the second clamping piece can clamp the first clamping piece, and when the sliding rod is in the second limit position, the top plate is in a state of being lowered by the lifting driving piece, and the second clamping piece clamps the sliding rod; the above design allows the locking assembly to have a smaller overall size, both in the first limit position and in the second limit position.

Preferably, the second clamping piece is rotatably provided with a locking piece, and the locking piece is used for limiting the rotation of the second clamping piece so as to limit the movement of the sliding rod.

By adopting the technical scheme, the locking piece can rotate and then limit the movement of the sliding rod, so that the sliding rod can be locked and kept at the first limit position or the second limit position.

Preferably, the second supporting mechanism comprises a fixed seat, the fixed seat is arranged on the output end of the jacking piece, a plurality of second supporting rods are arranged on the fixed seat, and one end, far away from the fixed seat, of each second supporting rod is arranged on the top plate.

Through adopting above-mentioned technical scheme, a plurality of second bracing pieces can play the supporting role to the roof.

Preferably, a sliding groove is formed in the top plate corresponding to each second supporting rod, and the sliding groove extends to the center of the top plate; each second support rod is hinged to the fixing base, a sliding piece is arranged at one end, away from the jacking piece, of each second support rod, the sliding piece is clamped in the sliding groove, and the jacking piece can drive the sliding pieces to slide so that the second support rods gather together.

Through adopting above-mentioned technical scheme, after the roof was risen, can drive jacking piece and drive the fixing base and remove to make a plurality of second bracing pieces gather together mutually, then reduce the shared space of a plurality of second bracing pieces.

Preferably, the plurality of second support rods are uniformly distributed along the circumferential direction.

Through adopting above-mentioned technical scheme, a plurality of second supporting rods that so set up can be comparatively even distribution to the holding power of top board.

Preferably, the fixing seat is higher than the mounting seat, a plurality of bearing columns are arranged at the top end of the mounting seat, and one end, far away from the mounting seat, of each bearing column is arranged at the bottom end of the fixing seat.

Through adopting above-mentioned technical scheme, a plurality of force-bearing columns can make first supporting mechanism not only play the supporting role to the output of jacking piece, and a plurality of force-bearing columns can also directly play the supporting role to second supporting mechanism.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the two-stage lifting of the top plate can be realized, and the specific actions can be realized as follows: the first oil port is used for oil feeding, the third oil port is used for oil discharging, oil entering the first cavity from the first oil port enters the third cavity through the through hole, and the oil pushes the second piston to move, so that the jacking rod drives the top plate to move, and the second cylinder body does not act at the moment; and then the third oil port stops oil discharge, the second oil port discharges oil, and the oil can push the first piston to move, so that the second cylinder body moves, and the jacking rod can drive the top plate to move again. The roof can drive the roof to descend by a part through the actions, so that people can be accommodated in the caravan after the height limiting requirement is met;

2. after the lifting driving piece lifts the top plate, the lifting driving piece is driven to drive the first supporting mechanism and the second supporting mechanism to move, the first supporting mechanism can support the output end of the lifting piece, the second supporting mechanism arranged on the output end of the lifting piece can support the top plate, and the bearing capacity of the top plate can be increased as much as possible through the combination of the first supporting mechanism and the second supporting mechanism;

3. the rotation locking piece can limit the movement of the sliding rod, so that the sliding rod can be locked to maintain the first limit position or the second limit position, and then the movement of the sliding block is limited;

4. when the top plate is lifted, the jacking piece can be driven to drive the fixing seat to move, so that the plurality of second support rods are gathered together, and the occupied space of the plurality of second support rods is reduced.

Drawings

FIG. 1 is a schematic overall structure of one view of a roof lifting device for a motor home according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a structure for embodying a lift drive;

FIG. 3 is a schematic view of a structure for embodying the roof mounting plate raised by the present application;

FIG. 4 is a schematic overall structure of another view angle of a roof lifting device for a motor home according to an embodiment of the present application;

FIG. 5 is an enlarged view of portion A of FIG. 4;

FIG. 6 is a schematic view of a structure for embodying the locking assembly with the slide bar in the first extreme position;

FIG. 7 is a schematic view of a structure for embodying the locking assembly with the slide bar in the neutral position;

FIG. 8 is a schematic view of a structure for embodying the locking assembly with the slide bar in the second extreme position;

fig. 9 is a schematic structural view for embodying the second supporting mechanism.

The reference numerals in the drawings: 1. a vehicle body; 11. a roof mounting plate; 2. a bottom plate; 21. a mounting shell; 211. a receiving hole; 22. a jacking member; 23. a first support mechanism; 231. a guide assembly; 2311. a mounting base; 23111. a force bearing column; 2312. a first support bar; 2313. a slide block; 2314. a chute; 232. a locking assembly; 2321. a mounting block; 23211. a third hinge shaft; 2322. a sliding hole; 2323. a slide bar; 2324. a connecting block; 2325. a first clamping piece; 23251. a first hinge shaft; 2326. a second clamping piece; 23261. a second hinge shaft; 2327. a locking member; 24. a second support mechanism; 241. a fixing seat; 242. a second support bar; 243. a slider; 244. a sliding groove; 3. a lifting driving member; 31. a first cylinder; 311. a first chamber; 312. a second chamber; 313. a first oil port; 314. a second oil port; 32. a second cylinder; 321. a first piston; 3211. a through hole; 322. a third chamber; 323. a fourth chamber; 324. a third oil port; 33. a lifting rod; 331. a second piston; 4. a top plate; 5. a hemispherical flange.

Detailed Description

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

In the description of the present application, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

Referring to fig. 1, the present application is based on a vehicle mounted to achieve a secondary lifting of a roof, the vehicle including a vehicle body 1 and a roof mounting plate 11, the present application being mounted to the vehicle body 1 with a top end of the present application connected to the roof mounting plate 11, the roof mounting plate 11 being driven to perform a secondary lifting by driving the present application.

The embodiment of the application discloses a lifting device for a motor home. Referring to fig. 1 and 2, the car as a house jack-up device includes bottom plate 2 and roof 4 that from the bottom up set gradually, and bottom plate 2 installs on vehicle body 1, and roof 4 pastes and locates roof mounting panel 11 bottom, and the bottom plate 2 top is equipped with four lift driving pieces 3, and four lift driving pieces 3 are located the four corners department of bottom plate 2 respectively, and the output of each lift driving piece 3 all links to each other with roof 4 bottom, can drive roof 4 through the synchronous work of four lift driving pieces 3 and carry out the second grade and go up and down to drive roof mounting panel 11 second grade and go up and down.

Referring to fig. 2, specifically, four lifting driving members 3 have the same structure, and taking the structure of one lifting driving member 3 as an example: the lifting driving piece 3 comprises a first cylinder body 31, a second cylinder body 32 and a lifting rod 33 which are sequentially arranged from bottom to top, the first cylinder body 31, the second cylinder body 32 and the lifting rod 33 are coaxially arranged, the bottom end of the second cylinder body 32 is slidably arranged in the first cylinder body 31, and the bottom end of the lifting rod 33 is slidably arranged in the second cylinder body 32; the second cylinder 32 comprises a first piston 321 positioned in the first cylinder 31, the first piston 321 divides the inner space of the first cylinder 31 into a first cavity 311 and a second cavity 312 from bottom to top, the first cylinder 31 is provided with a first oil port 313 and a second oil port 314, the first oil port 313 is communicated with the first cavity 311, and the second oil port 314 is communicated with the second cavity 312; the lifting rod 33 comprises a second piston 331 located in the second cylinder 32, the second piston 331 divides the inner space of the second cylinder 32 into a third cavity 322 and a fourth cavity 323 from bottom to top, a through hole 3211 is formed in the first piston 321, the third cavity 322 is communicated with the first cavity 311 through the through hole 3211, a third oil port 324 is formed in the second cylinder 32, and the third oil port 324 is communicated with the fourth cavity 323. Referring to fig. 1, in order to make the top plate 4 have a certain micro-motion capability, a hemispherical flange 5 is disposed at the connection between the lifting rod 33 and the top plate 4, and the hemispherical flange 5 can make a certain adjustment amount at the connection between the lifting rod 33 and the top plate 4.

The secondary lifting action process of the top plate 4 is as follows: the first oil port 313 is used for oil feeding, the third oil port 324 is used for oil discharging, the oil entering the first cavity 311 from the first oil port 313 enters the third cavity 322 through the through hole 3211, the oil pushes the second piston 331 to move upwards, so that the lifting rod 33 drives the top plate 4 to move upwards, the top plate 4 is lifted for the first stage, and the second cylinder 32 does not act; after that, the third oil port 324 stops discharging oil, the second oil port 314 discharges oil, and the oil pushes the first piston 321 to move upwards, so that the second cylinder 32 moves upwards, and the lifting rod 33 drives the top plate 4 to move upwards again, which is the second stage lifting of the top plate 4. In addition, the distance of the lifting and lowering of the top plate 4 can be controlled by flexibly controlling the oil inlet and outlet amount of the first oil port 313, so that the top plate 4 is locked and positioned.

The secondary descending action process of the top plate 4 is as follows: on the basis that the top plate 4 is completely lifted, the third oil port 324 is used for oil feeding, the first oil port 313 is used for oil discharging, and the oil drives the second piston 331 to move downwards, so that the first stage of the top plate 4 descends; after that, the second oil port 314 is filled with oil, the first oil port 313 continues to discharge oil, and the first piston 321 descends, which is the second stage of the top plate 4 descends.

Referring to fig. 3 and 4, the central position of the top end of the bottom plate 2 is further fixedly provided with a mounting housing 21, the front end and the top end of the mounting housing 21 are both in an open state, a jacking member 22 is arranged on the inner bottom surface of the mounting housing 21, the jacking member 22 is a hydraulic cylinder, a first supporting mechanism 23 and a second supporting mechanism 24 are arranged on the output end of the jacking member 22, the first supporting mechanism 23 is used for supporting the output end of the jacking member 22, the second supporting mechanism 24 is used for supporting the top plate 4, and the first supporting mechanism 23 and the second supporting mechanism 24 can move under the driving of the jacking member 22. Since the four lifting driving members 3 can drive the top plate 4 to lift, the top plate 4 has two states of a high state and a low state, but the first supporting mechanism 23 can always support the output end of the lifting member 22 and the second supporting mechanism 24 can always support the top plate 4 no matter whether the top plate 4 is in the high state or the low state.

Referring to fig. 4 and 5, specifically, the first supporting mechanism 23 includes a guide assembly 231 and a locking assembly 232, the guide assembly 231 is disposed on the output end of the jack 22, and the guide assembly 231 is used for guiding the up-and-down movement of the output end of the jack 22; the locking assembly 232 is disposed in the mounting housing 21, and the locking assembly 232 enables the locking assembly 232 to always lock and support the output end of the jacking member 22 through the guide assembly 231, regardless of whether the top plate 4 is in the high position or the low position, so that the top plate 4 is locked and supported by the second supporting mechanism 24 mounted on the output end of the jacking member 22.

Referring to fig. 5, more specifically, the guide assembly 231 includes a mounting seat 2311, and the mounting seat 2311 is disposed on the output end of the jacking member 22; four first supporting rods 2312 are movably arranged on the side wall of the mounting seat 2311, sliding blocks 2313 are movably arranged at the lower end of each first supporting rod 2312, a sliding groove 2314 is formed in the inner wall of the mounting shell 21, the sliding blocks 2313 are clamped in the sliding grooves 2314 and can slide along the vertical direction, and the design can guide the movement of the output end of the jacking piece 22.

Referring to fig. 4 and 5, the locking assemblies 232 are provided in two and are all disposed in the mounting housing 21, and one locking assembly 232 locks two sliders 2313 correspondingly, and the two locking assemblies 232 have the same and symmetrical structure, taking the structure of the left locking assembly 232 as an example: referring to fig. 6, the locking assembly 232 includes a mounting block 2321, the mounting block 2321 is fixedly disposed on the mounting housing 21, a sliding hole 2322 disposed along a vertical direction is formed in the mounting block 2321, a sliding rod 2323 is disposed in the sliding hole 2322 in a penetrating manner, and the sliding rod 2323 can slide along the vertical direction.

With reference to fig. 6 and 7, continuing to exemplify the structure of the left locking assembly 232: the top end of the sliding rod 2323 is fixedly connected with the two sliding blocks 2313 through a connecting block 2324, two first clamping pieces 2325 are hinged to the side wall, close to the bottom end, of the sliding rod 2323 through two first hinge shafts 23251, the two first clamping pieces 2325 are symmetrical to each other, a second clamping piece 2326 is hinged to one end, far away from the sliding rod 2323, of each first clamping piece 2325 through a second hinge shaft 23261, the two second clamping pieces 2326 are symmetrical to each other, one end, far away from the first clamping piece 2325, of each second clamping piece 2326 is hinged to the mounting block 2321 through a third hinge shaft 23211, the axis of the first hinge shaft 23251, the axis of the second hinge shaft 23261 and the axis of the third hinge shaft 23211 are parallel to each other, and in order to prevent dead points in the movement process of the locking assembly 232, and projection of the first hinge shaft 23251 and the third hinge shaft 23211 on a vertical plane is misplaced with each other. In addition, the second engaging member 2326 on the left side is rotatably provided with a locking member 2327, and the locking member 2327 is used to limit rotation of the two second engaging members 2326 so as to limit movement of the sliding rod 2323.

Referring to fig. 4, the sliding rod 2323 also has a respective highest first limit position and a lowest second limit position corresponding to the high state and the low state of the top plate 4, and fig. 6, 7 and 8 are, in combination, schematic structural views sequentially shown as the sliding rod 2323 being in the first limit position, the intermediate position and the second limit position. When the sliding rod 2323 is located at the first limit position, the two second engaging members 2326 engage the two first engaging members 2325, and the locking member 2327 is sleeved on the two second engaging members 2326 to limit rotation of the two second engaging members 2326, so that the sliding rod 2323 cannot move; when the sliding rod 2323 is located at the second limit position, the two second engaging members 2326 engage the sliding rod 2323, and the locking member 2327 can be sleeved on the two second engaging members 2326 and also limit the two second engaging members 2326 to rotate, so that the sliding rod 2323 cannot move. The above arrangement allows the locking member 2327 to always restrict movement of the sliding bar 2323, whether the top plate 4 is in the high state or the low state. Referring again to fig. 4, in order to prevent the sliding bar 2323 from striking the inner bottom of the installation housing 21 during the downward movement, the inner bottom of the installation housing 21 is provided with a receiving hole 211 corresponding to each sliding bar 2323, and the receiving hole 211 penetrates the bottom plate 2 downward.

Referring to fig. 9, the second supporting mechanism 24 includes a fixing base 241, the fixing base 241 is disposed on an output end of the jacking member 22, the fixing base 241 is located above the mounting seat 2311, six second supporting rods 242 are hinged on the fixing base 241, the six second supporting rods 242 are uniformly distributed along a circumferential direction, a sliding member 243 is disposed at an upper end of each second supporting rod 242, the sliding member 243 is a sliding ball, a sliding groove 244 is disposed on a lower end surface of the top plate 4 corresponding to each second supporting rod 242, the sliding groove 244 extends toward a center of the top plate 4, the sliding member 243 is clamped in the sliding groove 2314, and when the top plate 4 is motionless, the output end of the jacking member 22 descends to drive the six sliding members 243 to slide toward a center position of the top plate 4, so that the six second supporting rods 242 gather together.

When the vehicle body 1 runs to the open area, the possibility of falling of the heavy objects is low, and at this time, in order to reduce the space occupied by the present application, the lifting member can be driven to drive the fixing seat 241 to move downward, so that the six second support rods 242 gather together.

Referring to fig. 9, in order to make the first supporting mechanism 23 not only support the output end of the jack-up member 22, but also support the second supporting mechanism 24, the top end of the mounting seat 2311 is provided with a plurality of bearing columns 23111, and the upper end of each bearing column 23111 is fixedly arranged at the bottom end of the fixing seat 241.

The implementation principle of the roof lifting device of the motor home in the embodiment of the application is as follows: the four lifting driving pieces 3 are driven to jack up the top plate 4, then after the top plate 4 reaches a high-position state, the plurality of second supporting rods 242 are in a gathering state, then the two locking pieces 2327 are required to be rotated firstly, the locking pieces 2327 release the locking of the two second clamping pieces 2326, then the lifting piece 22 is driven, at the moment, along with the rising of the output end of the lifting piece 22, the fixing seat 241 moves upwards, the plurality of sliding pieces 243 slide towards the peripheral direction of the top plate 4, and the plurality of second supporting rods 242 scatter to support the top plate 4; and along with the upward movement of the fixing base 241, the mounting seat 2311 and the sliding blocks 2313 also move upward, the sliding rod 2323 can be changed from the second limit position to the first limit position, and then the locking piece 2327 is rotated to sleeve the two second clamping pieces 2326 so as to lock the two second clamping pieces 2326, so that the locking of the top plate 4 in the high-position state can be completed.

The embodiments of the present application are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in this way, therefore: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims (10)

1. The utility model provides a car as a house jack-up device which characterized in that: the lifting device comprises a bottom plate (2), wherein a lifting driving piece (3) is arranged on the bottom plate (2), and a top plate (4) is arranged at the output end of the lifting driving piece (3);

the lifting driving piece (3) comprises a first cylinder body (31), a second cylinder body (32) and a lifting rod (33) which are sequentially arranged, one end of the second cylinder body (32) is slidably arranged in the first cylinder body (31), and one end of the lifting rod (33) is slidably arranged in the second cylinder body (32);

the second cylinder body (32) comprises a first piston (321) positioned in the first cylinder body (31), the first piston (321) divides the inner space of the first cylinder body (31) into a first cavity (311) and a second cavity (312), a first oil port (313) and a second oil port (314) are formed in the first cylinder body (31), the first oil port (313) is communicated with the first cavity (311), and the second oil port (314) is communicated with the second cavity (312);

the jacking rod (33) comprises a second piston (331) located in the second cylinder body (32), the second piston (331) divides the inner space of the second cylinder body (32) into a third cavity (322) and a fourth cavity (323), a through hole (3211) is formed in the first piston (321), the third cavity (322) is communicated with the first cavity (311) through the through hole (3211), a third oil port (324) is formed in the second cylinder body (32), and the third oil port (324) is communicated with the fourth cavity (323).

2. The caravan lifting device of claim 1, wherein:

the bottom plate (2) is also provided with a mounting shell (21), the mounting shell (21) is provided with a jacking piece (22), the output end of the jacking piece (22) is provided with a first supporting mechanism (23) and a second supporting mechanism (24), the first supporting mechanism (23) is used for supporting the output end of the jacking piece (22), and the second supporting mechanism (24) is used for supporting the top plate (4);

the first supporting mechanism (23) comprises a guide assembly (231) and a locking assembly (232), the guide assembly (231) is arranged on the output end of the jacking piece (22), the guide assembly (231) is used for guiding the moving direction of the output end of the jacking piece (22), the locking assembly (232) is arranged in the installation shell (21), and the locking assembly (232) is used for locking and supporting the output end of the jacking piece (22).

3. The caravan lifting device of claim 2, wherein: the guide assembly (231) comprises a mounting seat (2311), and the mounting seat (2311) is arranged at the output end of the jacking piece (22); the movable first support rod (2312) that is equipped with on mount pad (2311), the one end activity that mount pad (2311) was kept away from to first support rod (2312) is equipped with slider (2313), it has spout (2314) to open on the inner wall of installation casing (21), slider (2313) card is in spout (2314) and slider (2313) can be along the direction of movement slip of jacking piece (22).

4. The caravan lifting device of claim 2, wherein: the locking assembly (232) comprises a mounting block (2321), the mounting block (2321) is arranged on the mounting shell (21), a sliding hole (2322) is formed in the mounting block (2321), a sliding rod (2323) is arranged in the sliding hole (2322) in a penetrating mode, and the sliding rod (2323) can slide along the moving direction of the jacking piece (22); the top of sliding rod (2323) passes through connecting block (2324) and links to each other with slider (2313), it has first fastener (2325) to articulate on the lateral wall that sliding rod (2323) is close to the bottom, one end that sliding rod (2323) was kept away from to first fastener (2325) articulates there is second fastener (2326), one end that first fastener (2325) was kept away from to second fastener (2326) is articulated with installation piece (2321).

5. The caravan lifting device of claim 4, wherein: the sliding rod (2323) is driven by the sliding block (2313) to have a first limit position and a second limit position, and the first limit position is higher than the second limit position; when the sliding rod (2323) is in a first limit position, the second clamping piece (2326) can clamp the first clamping piece (2325); when the sliding rod (2323) is in the second limit position, the second engagement member (2326) can engage the sliding rod (2323).

6. The caravan lifting device of claim 5, wherein: the second clamping piece (2326) is rotatably provided with a locking piece (2327), and the locking piece (2327) is used for limiting rotation of the second clamping piece (2326) so as to limit movement of the sliding rod (2323).

7. The caravan lifting device of claim 2, wherein: the second supporting mechanism (24) comprises a fixed seat (241), the fixed seat (241) is arranged on the output end of the jacking piece (22), a plurality of second supporting rods (242) are arranged on the fixed seat (241), and one end, far away from the fixed seat (241), of each second supporting rod (242) is arranged on the top plate (4).

8. The caravan lifting device of claim 7, wherein: a sliding groove (244) is formed in the top plate (4) corresponding to each second supporting rod (242), and the sliding groove (244) extends to the center of the top plate (4); each second supporting rod (242) is hinged to the fixing base (241), a sliding piece (243) is arranged at one end, far away from the jacking piece (22), of each second supporting rod (242), the sliding piece (243) is clamped in the sliding groove (2314), and the jacking piece (22) can drive the sliding pieces (243) to slide so that the second supporting rods (242) can be gathered.

9. The caravan lifting device of claim 8, wherein: the second support rods (242) are uniformly distributed along the circumferential direction.

10. The caravan lifting device of claim 9, wherein: the fixing base (241) is higher than the mounting base (2311), a plurality of bearing columns (23111) are arranged at the top end of the mounting base (2311), and one end, far away from the mounting base (2311), of each bearing column (23111) is arranged at the bottom end of the fixing base (241).