Length-adjustable trailer chassis

Abstract

The invention discloses a length-adjustable trailer motor home chassis, and belongs to the field of trailer motor home chassis, the length-adjustable trailer motor home chassis comprises a frame, supports are symmetrically mounted on the bottom wall of the frame, a rotating shaft is mounted on the two supports, and wheels are rotatably mounted at the two ends of the rotating shaft; a movable groove is formed in the frame, an extension frame is slidably mounted in the movable groove, and a fixing mechanism for fixing the extension frame at a specified position is arranged on the frame; extension plates are vertically, symmetrically and fixedly welded to the bottom wall of the end, away from the movable groove, of the extension frame; the movable arc-shaped plate and the fixed arc-shaped plate are fixed together through the bolt, so that the fixing effect on the extension frame is improved, the shaking probability of the extension frame is reduced, meanwhile, when the extension frame is pressed, part of pressure can be transmitted to the rotating shaft through the supporting rod, the pressure borne by the connecting part of the frame and the extension rod is reduced, and the service life of the extension frame is prolonged. The abrasion degree of the connecting part is reduced, namely, the damage probability of the connecting part is reduced, and the overall safety and stability of the touring car chassis are improved.

Description

Technical Field

[0001] The present invention relates to the field of trailer caravan chassis, and more particularly to a trailer caravan chassis with adjustable length. Background Art

[0002] RV is a fashionable and convenient vehicle. The household facilities on board include: bedding, stoves, refrigerators, cabinets, sofas and other furniture and electrical appliances. It can be divided into driving area, living area, bedroom area, etc.; trailer RV is a branch of RV. Unlike self-propelled RV, trailer RV has no power of its own and requires an additional vehicle to tow it.

[0003] There are many types of RVs, and the adjustable-length chassis can adapt to RV bodies of various sizes; for the adjustable-length RV chassis, it usually contains more movable parts and connecting mechanisms, such as telescopic rods, sliding rails, locking devices, etc.

[0004] For RV chassis with flexible length adjustment, in normal use, a pull-out adjustment method is usually used to meet different needs. However, after the pull-out adjustment, if heavy objects need to be placed on the extended part during use, these heavy objects will inevitably exert downward pressure on the extended part. At this time, this pressure will directly act on the connection between the extended part and the chassis. Since this connection is relatively fragile, it is easy to cause the connection to loosen, deform or even break under continuous pressure, thereby affecting the overall stability and safety of the RV chassis.

[0005] For this reason, a trailer caravan chassis with adjustable length is proposed. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a trailer RV chassis with adjustable length, which can provide stable support force for the extended part of the RV chassis and improve safety.

[0007] To solve the above problems, the present invention adopts the following technical solutions.

[0008] A trailer caravan chassis with adjustable length includes a frame, brackets are symmetrically mounted on the bottom wall of the frame, and a rotating shaft is commonly mounted on the two brackets; The frame is provided with a movable groove, in which an extension frame is slidably installed, and the frame is provided with a fixing mechanism for fixing the extension frame at a designated position; An extension plate is vertically installed on the bottom wall of the extension frame, and a mounting rod is installed on the side wall of the extension plate. The mounting rod is located below the plane where the bottom wall of the frame is located. A support rod is rotatably sleeved on the mounting rod, and a locking mechanism is provided at one end of the support rod away from the mounting rod. The locking mechanism is used to fix the support rod to the rotating shaft, and brackets for lifting the support rod are evenly and fixedly installed on the bottom wall of the frame.

[0009] Furthermore, the fixing mechanism includes a pressure plate mounted on the top wall of the frame, the pressure plate covers the surface of the movable groove, so that under the action of the pressure plate, the extension frame can be prevented from rotating when the extension frame is subjected to pressure; An upper fixing hole is provided on the pressing plate, and a lower fixing hole is provided on the bottom wall of the movable groove; The extension frame is provided with a movable hole, in which an inserting rod which is matched with the upper fixing hole and the lower fixing hole is vertically slidably inserted.

[0010] Furthermore, the locking mechanism comprises a fixed arc plate and a movable arc plate, wherein the fixed arc plate is fixedly mounted on the end of the support rod away from the mounting rod; and the movable arc plate is detachably mounted on the fixed arc plate by bolts.

[0011] When the extension frame is extended from the movable groove, the support rod is pulled out from each bracket in turn. When the support rod is out of contact with the last bracket, the support rod is rotated to rotate the support rod around the mounting rod, and then the extension frame is pushed to retract the extension frame into the movable groove until the fixed arc plate on the support rod rotates to the surface of the rotating shaft. At this time, the projections of the upper fixing hole, the movable hole and the lower fixing hole on the ground are concentric circles, and then the insertion rod is inserted into the upper fixing hole, the movable hole and the lower fixing hole, so that the extension frame can be fixed at the specified position; then the movable arc plate is sleeved on the rotating shaft, so that the movable arc plate and the fixed arc plate form a circular ring, and the rotating shaft is located in the circular ring, and then the movable arc plate and the fixed arc plate are fixed together by bolts, thereby improving the fixing effect of the extension frame and reducing the probability of the extension frame shaking. At the same time, when the extension frame is subjected to pressure, part of the pressure can be transmitted to the rotating shaft through the support rod, thereby reducing the pressure on the connection part between the frame and the extension rod, reducing the degree of wear of the connection part, that is, reducing the probability of damage to the connection, and improving the overall safety and stability of the RV chassis.

[0012] Furthermore, a cavity is provided on the extension frame, and lubricating oil is filled in the cavity. A hole communicating with the movable hole is provided on the side wall of the cavity, and an extrusion mechanism for extruding the lubricating oil is provided on the extension frame.

[0013] Furthermore, the extrusion mechanism includes a push plate vertically slidably installed on the side wall of the cavity, the push plate and the hole are located on the side wall on the same side of the cavity, a baffle is fixedly installed on the top wall of the push plate away from the hole, both ends of the baffle and the push plate are in contact with the side wall of the cavity, a memory alloy wire is jointly installed between the push plate and the bottom wall of the cavity, and a heat-conducting rod fixedly connected to the memory alloy wire is embedded on the side wall of the movable hole.

[0014] During the swinging of the extension frame, friction occurs between the insertion rod and the movable hole, the upper fixed hole and the lower fixed hole. The heat generated by the friction is transferred to the heat-conducting rod through heat exchange, and then to the memory alloy wire, so that the memory alloy wire can be stretched. During the stretching of the memory alloy wire, the push plate is driven to extend from the lubricating oil liquid surface and move upward. At this time, the space between the side wall of the cavity, the side wall of the baffle and the top wall of the push plate contains lubricating oil, and this part of the lubricating oil moves upward with the push plate; When the space between the side walls of the cavity, the side walls of the baffle and the top wall of the push plate is connected to the hole, the lubricating oil pushed upward will enter the hole. The lubricating oil entering the hole contacts the side walls of the plug rod, and then can lubricate the side walls of the plug rod, reducing the friction between the plug rod and the movable hole, the upper fixed hole and the lower fixed hole, preventing the degree of wear from deepening, and improving the stability and safety of the RV chassis.

[0015] Furthermore, the hole is in a truncated cone shape, and the diameter of the hole gradually decreases as the distance between the hole and the insertion rod decreases.

[0016] Therefore, the excess lubricating oil in the hole will flow into the cavity, which can reduce the lubricating oil consumption, save costs and increase the number of oiling times.

[0017] Furthermore, a spring is installed between the movable slot and the extension frame; when the extension frame is extended from the movable slot, the spring is in a deformed state, and at this time the spring has a tendency to recover, so the extension frame is subjected to horizontal pulling force, and the pulling force has a tendency to retract the extension frame into the movable slot, so that the insertion rod can exert pressure on the side walls of the upper fixing hole, the lower fixing hole and the movable hole, so that the insertion rod is tightly fixed to the side walls of the upper fixing hole, the lower fixing hole and the movable hole, thereby reducing the probability of the extension frame shaking and improving the protection effect of the connection between the frame and the extension frame.

[0018] Furthermore, the support rod comprises a sleeve and an extension rod, the sleeve is rotatably sleeved on the mounting rod, the extension rod is movably inserted in the sleeve, and the fixed arc plate is fixedly mounted on the end of the extension rod; A telescopic rod is fixedly installed in the sleeve, an output end of the telescopic rod is fixedly connected with the extension rod, and a trigger mechanism for triggering the telescopic rod to work is arranged on the vehicle frame.

[0019] Furthermore, the trigger mechanism includes an inner mounting groove and an outer mounting groove provided on the bottom wall of the extension frame, the inner mounting groove and the outer mounting groove are always located above the movable groove, and the spacing between the inner mounting groove and the outer mounting groove is 40-60 cm, the inner mounting groove and the outer mounting groove are respectively provided with an inner ranging module and an outer ranging module, and the top walls of the inner mounting groove and the outer mounting groove are in the same horizontal plane, and the inner ranging module and the outer ranging module are ultrasonic ranging sensors of the same model; therefore, when the extension frame is in a horizontal state, the data detected by the inner ranging module and the outer ranging module are the same; buffer pads are installed on the top wall and the bottom wall of the extension frame, and since buffer pads are installed on the top wall and the bottom wall of the extension frame, when the extension frame is subjected to uniform force, each part of each buffer pad is subjected to uniform force and the degree of deformation is also the same, that is, the extension frame is in a stable state, so that the connection part between the extension frame and the frame will not be subjected to excessive pressure, and a detection hole is provided on the buffer pad on the bottom wall of the extension frame, and the detection hole passes through the buffer pad; The frame is provided with a calculation module, a comparison module and a control module; The internal distance measurement module and the external distance measurement module simultaneously send the detected data to the calculation module; The calculation module calculates the received data and sends the calculation result to the comparison module; The comparison module sends the comparison result to the control module; The control module is used to control the extension amount of the telescopic rod.

[0020] Furthermore, the calculation module calculates the received data: Wherein, B is the difference between the data detected by the inner ranging module and the outer ranging module; d 内 The distance between the position of the inner distance measuring module detected by the inner distance measuring module and the bottom wall of the movable slot; d 外 The distance between the position of the external distance measuring module detected by the external distance measuring module and the bottom wall of the movable groove; The comparison module compares the received data: When B=0, the control module does not work; When B≠0, the control module works and the telescopic rod extends. At the same time, the internal distance measurement module, the external distance measurement module, the calculation module and the comparison module work synchronously. When B=0 again, the control module stops working.

[0021] Since the vehicle will pass through bumpy sections during driving, the connection between the frame and the extension frame is easy to shake when passing through bumpy sections. At this time, under the action of friction, the connection is easy to loosen. Therefore, when the extension frame is subjected to greater pressure, the extension frame will not be able to maintain a horizontal state. At this time, the data detected by the internal distance measurement module and the external distance measurement module are sent to the calculation module, and the calculation module sends the calculation result to the comparison module, and then the comparison module sends the comparison result to the control module, so that the telescopic rod can be controlled to work when the extension frame is not in a horizontal state, so that the telescopic rod is extended until the extension frame is in a horizontal state again. In this way, the pressure on the connection between the frame and the extension frame can be reduced, the protection effect on this part is improved, and the stability of the RV chassis is improved.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) The movable arc plate and the fixed arc plate are fixed together by bolts, thereby improving the fixing effect of the extension frame and reducing the probability of the extension frame shaking. At the same time, when the extension frame is under pressure, part of the pressure can be transferred to the rotating shaft through the support rod, reducing the pressure on the connection between the frame and the extension rod, reducing the degree of wear at the connection, that is, reducing the probability of damage to the connection, and improving the overall safety and stability of the RV chassis; (2) When the extension frame is not in a horizontal state, the telescopic rod can be controlled to work and extend until the extension frame is in a horizontal state again. This can reduce the pressure on the connection between the frame and the extension frame, improve the protection effect on the connection, and improve the stability of the RV chassis; (3) When the space between the side wall of the cavity, the side wall of the baffle and the top wall of the push plate is connected to the hole, the lubricating oil pushed upward will enter the hole. The lubricating oil entering the hole will contact the side wall of the plug rod, thereby lubricating the side wall of the plug rod, reducing the friction between the plug rod and the movable hole, the upper fixed hole and the lower fixed hole, preventing the degree of wear from deepening, and improving the stability and safety of the RV chassis. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the top view structure of the present invention; Figure 2 It is a bottom view structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the overall structure of the frame of the present invention; Figure 4 is a cross-sectional view of a frame of the present invention; Figure 5 It is a schematic diagram of the enlarged structure of A in FIG. 4 of the present invention; Figure 6 It is a schematic diagram of the enlarged structure of B in FIG. 4 of the present invention; Figure 7It is a working flow chart of the internal detection module, external detection module, calculation module, comparison module and control module of the present invention.

[0024] Description of the numbers in the figure: 1. Frame; 2. Bracket; 3. Rotating shaft; 4. Extension frame; 5. Extension plate; 6. Mounting rod; 7. Support rod; 701. Sleeve; 702. Extension rod; 8. Bracket; 9. Press plate; 10. Upper fixing hole; 11. Lower fixing hole; 12. Movable hole; 13. Insert rod; 14. Fixed arc plate; 15. Moving arc plate; 16. Cavity; 17. Hole; 18. Push plate; 19. Baffle; 20. Memory alloy wire; 21. Heat conducting rod; 22. Spring; 23. Telescopic rod; 24. Internal distance measuring module; 25. External distance measuring module; 26. Buffer pad; 27. Calculation module; 28. Comparison module; 29. ​​Control module. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention. Embodiment 1:

[0026] See also Figures 1 to 7 A trailer caravan chassis with adjustable length includes a frame 1, brackets 2 are symmetrically mounted on the bottom wall of the frame 1, a rotating shaft 3 is commonly mounted on the two brackets 2, and wheels are rotatably mounted on both ends of the rotating shaft 3; The frame 1 is provided with a movable groove, in which an extension frame 4 is slidably installed, and the frame 1 is provided with a fixing mechanism for fixing the extension frame 4 at a specified position; An extension plate 5 is vertically and symmetrically fixedly welded on the bottom wall of the extension frame 4 at one end away from the movable groove, and a mounting rod 6 is welded on the side wall of the extension plate 5. The mounting rod 6 is parallel to the rotating shaft 3 and is located below the plane where the bottom wall of the frame 1 is located. A support rod 7 is rotatably sleeved on the mounting rod 6. A locking mechanism is provided at one end of the support rod 7 away from the mounting rod 6. The locking mechanism is used to fix the support rod 7 to the rotating shaft 3. A U-shaped bracket 8 with an opening upward is evenly fixedly installed on the bottom wall of the frame 1. The bracket 8 is used to store the support rod 7 to prevent the end of the support rod 7 away from the mounting rod 6 from rotating to the ground or hanging in the air, thereby improving the safety during driving. The fixing mechanism includes a pressure plate 9 mounted on the top wall of the frame 1, and the pressure plate 9 covers the surface of the movable groove, so that under the action of the pressure plate 9, the extension frame 4 can be prevented from rotating when the extension frame 4 is subjected to pressure; An upper fixing hole 10 is formed on the pressing plate 9, and a lower fixing hole 11 is formed on the bottom wall of the movable groove; The extension frame 4 is provided with a movable hole 12 , into which a plug rod 13 is vertically slidably inserted to cooperate with the upper fixing hole 10 and the lower fixing hole 11 .

[0027] The locking mechanism comprises a fixed arc plate 14 and a movable arc plate 15 . The fixed arc plate 14 is fixedly mounted on the end of the support rod 7 away from the mounting rod 6 ; the movable arc plate 15 is detachably mounted on the fixed arc plate 14 by bolts.

[0028] During the process of extending the extension frame 4 from the movable groove, the support rod 7 is pulled out from each bracket 8 in turn. When the support rod 7 is out of contact with the last bracket 8, the support rod 7 is rotated to rotate the support rod 7 around the mounting rod 6, and then the extension frame 4 is pushed to retract the extension frame 4 into the movable groove until the fixed arc plate 14 on the support rod 7 rotates to the surface of the rotating shaft 3. At this time, the projections of the upper fixing hole 10, the movable hole 12 and the lower fixing hole 11 on the ground are concentric circles. Then the insertion rod 13 is inserted into the upper fixing hole 10, the movable hole 12 and the lower fixing hole 11, so that the extension frame 4 can be fixed at the specified position; then the movable hole 12 is moved to the movable hole 12, and the lower fixing hole 1 ... The arc plate 15 is sleeved on the rotating shaft 3, so that the movable arc plate 15 and the fixed arc plate 14 form a circular ring, and the rotating shaft 3 is located in the circular ring, and then the movable arc plate 15 and the fixed arc plate 14 are fixed together by bolts, thereby improving the fixing effect of the extension frame 4 and reducing the probability of the extension frame 4 shaking. At the same time, when the extension frame 4 is subjected to pressure, part of the pressure can be transmitted to the rotating shaft 3 through the support rod 7, thereby reducing the pressure on the connection part between the frame 1 and the extension rod 702, reducing the degree of wear on the connection part, that is, reducing the probability of damage to the connection, and improving the overall safety and stability of the RV chassis.

[0029] As shown in FIG. 5 , a cavity 16 is provided on the extension frame 4 , and lubricating oil is filled in the cavity 16 . A hole 17 communicating with the movable hole 12 is provided on the side wall of the cavity 16 , and an extrusion mechanism for extruding the lubricating oil is provided on the extension frame 4 .

[0030] The extrusion mechanism includes a push plate 18 vertically slidably mounted on the side wall of the cavity 16. The push plate 18 and the hole 17 are located on the side wall on the same side of the cavity 16. A baffle 19 is fixedly mounted on the top wall of the push plate 18 away from the hole 17. Both ends of the baffle 19 and the push plate 18 are in contact with the side wall of the cavity 16. A memory alloy wire 20 is installed between the push plate 18 and the bottom wall of the cavity 16. A heat-conducting rod 21 fixedly connected to the memory alloy wire 20 is embedded on the side wall of the movable hole 12.

[0031] During the shaking of the extension frame 4, friction occurs between the insertion rod 13 and the movable hole 12, the upper fixing hole 10 and the lower fixing hole 11. The heat generated by the friction is transferred to the heat-conducting rod 21 by heat exchange, and then to the memory alloy wire 20, so that the memory alloy wire 20 can be stretched. During the stretching of the memory alloy wire 20, the push plate 18 is driven to extend from the lubricating oil liquid surface and move upward. At this time, the space between the side wall of the cavity 16, the side wall of the baffle 19 and the top wall of the push plate 18 contains lubricating oil, and this part of the lubricating oil moves upward with the push plate 18; When the space between the side wall of the cavity 16, the side wall of the baffle 19 and the top wall of the push plate 18 is connected to the hole 17, the lubricating oil pushed upward will enter the hole 17. The lubricating oil entering the hole 17 contacts the side wall of the plug rod 13, and then can lubricate the side wall of the plug rod 13, thereby reducing the friction between the plug rod 13 and the movable hole 12, the upper fixed hole 10 and the lower fixed hole 11, preventing the degree of wear from deepening, and improving the stability and safety of the RV chassis.

[0032] As shown in FIG. 5 , the hole 17 is in a truncated cone shape, and the diameter of the hole 17 gradually decreases as the distance between the hole 17 and the insertion rod 13 decreases.

[0033] Therefore, the excess lubricating oil in the hole 17 will flow into the cavity 16, which can reduce the lubricating oil consumption, thus saving costs and increasing the number of oiling times.

[0034] As shown in FIG. 4 , a spring 22 is installed between the movable slot and the extension frame 4. When the extension frame 4 extends from the movable slot, the spring 22 is in a deformed state. At this time, the spring 22 has a tendency to recover. Therefore, the extension frame 4 is subjected to a horizontal pulling force, and the pulling force has a tendency to retract the extension frame 4 into the movable slot, so that the insertion rod 13 can apply pressure to the side walls of the upper fixing hole 10, the lower fixing hole 11, and the movable hole 12, so that the insertion rod 13 is tightly fixed to the side walls of the upper fixing hole 10, the lower fixing hole 11, and the movable hole 12, thereby reducing the probability of the extension frame 4 shaking and improving the protection effect of the connection part between the frame 1 and the extension frame 4.

[0035] As shown in FIG. 6 , the support rod 7 includes a sleeve 701 and an extension rod 702 . The sleeve 701 is rotatably sleeved on the mounting rod 6 , the extension rod 702 is movably inserted in the sleeve 701 , and the fixed arc plate 14 is fixedly mounted on the end of the extension rod 702 . The telescopic rod 23 is fixedly installed in the sleeve 701 , the output end of the telescopic rod 23 is fixedly connected to the extension rod 702 , and a trigger mechanism for triggering the telescopic rod 23 to work is provided on the vehicle frame 1 .

[0036] The trigger mechanism includes an inner mounting groove and an outer mounting groove opened on the bottom wall of the extension frame 4, the inner mounting groove and the outer mounting groove are always located above the movable groove, and the spacing between the inner mounting groove and the outer mounting groove is 40-60 cm, and the inner mounting groove and the outer mounting groove are respectively provided with an inner ranging module 24 and an outer ranging module 25, and the top walls of the inner mounting groove and the outer mounting groove are in the same horizontal plane, and the inner ranging module 24 and the outer ranging module 25 are ultrasonic ranging sensors of the same model; therefore, when the extension frame 4 is in a horizontal state, the inner ranging module 24 is the same as the data detected by the external ranging module 25; buffer pads 26 are installed on the top wall and the bottom wall of the extension frame 4. Since buffer pads 26 are installed on the top wall and the bottom wall of the extension frame 4, when the extension frame 4 is subjected to uniform force, each part of each buffer pad 26 is subjected to uniform force and the degree of deformation is also the same, that is, the extension frame 4 is in a stable state, so the connection part between the extension frame 4 and the frame 1 will not be subjected to excessive pressure. The buffer pad 26 on the bottom wall of the extension frame 4 is provided with a detection hole, and the detection hole passes through the buffer pad 26; The frame 1 is provided with a calculation module 27, a comparison module 28 and a control module 29; The internal distance measurement module 24 and the external distance measurement module 25 simultaneously send the detected data to the calculation module 27; The calculation module 27 calculates the received data and sends the calculation result to the comparison module 28; The comparison module 28 sends the comparison result to the control module 29; The control module 29 is used to control the extension amount of the telescopic rod 23 .

[0037] The calculation module 27 calculates the received data: Wherein, B is the difference between the data detected by the inner distance measurement module 24 and the outer distance measurement module 25; d 内 The distance between the position of the inner distance measuring module 24 and the bottom wall of the movable groove detected by the inner distance measuring module 24; d 外 The distance between the position of the external distance measuring module 25 detected by the external distance measuring module 25 and the bottom wall of the movable groove; The comparison module 28 compares the received data: When B=0, the control module 29 does not work; When B≠0, the control module 29 works, and the telescopic rod 23 extends. At the same time, the internal distance measurement module 24, the external distance measurement module 25, the calculation module 27, and the comparison module 28 work synchronously. When B=0 again, the control module 29 stops working.

[0038] Since the vehicle will pass through bumpy sections during driving, the connection between the frame 1 and the extension frame 4 is easy to shake when passing through bumpy sections. At this time, under the action of friction, the connection is easy to loosen. Therefore, when the extension frame 4 is subjected to greater pressure, the extension frame 4 will not be able to maintain a horizontal state. At this time, the data detected by the internal distance measurement module 24 and the external distance measurement module 25 are sent to the calculation module 27, and the calculation module 27 sends the calculation result to the comparison module 28, and then the comparison module 28 sends the comparison result to the control module 29, so that the telescopic rod 23 can be controlled to work when the extension frame 4 is not in a horizontal state, so that the telescopic rod 23 is extended until the extension frame 4 is in a horizontal state again. In this way, the pressure on the connection between the frame 1 and the extension frame 4 can be reduced, the protection effect on the part is improved, and the stability of the RV chassis is improved.

[0039] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A trailer caravan chassis with adjustable length, comprising a frame (1), brackets (2) being symmetrically mounted on the bottom wall of the frame (1), and a rotating shaft (3) being mounted on two brackets (2); Features: The vehicle frame (1) is provided with a movable groove, an extension frame (4) is slidably mounted in the movable groove, and a fixing mechanism for fixing the extension frame (4) at a specified position is provided on the vehicle frame (1); An extension plate (5) is vertically mounted on the bottom wall of the extension frame (4), a mounting rod (6) is mounted on the side wall of the extension plate (5), the mounting rod (6) is located below the plane where the bottom wall of the frame (1) is located, a support rod (7) is rotatably sleeved on the mounting rod (6), a locking mechanism is provided at one end of the support rod (7) away from the mounting rod (6), the locking mechanism is used to fix the support rod (7) to the rotating shaft (3), and a bracket (8) for lifting the support rod (7) is evenly and fixedly mounted on the bottom wall of the frame (1).

2. The length-adjustable trailer chassis according to claim 1, characterized in that: The fixing mechanism comprises a pressure plate (9) mounted on the top wall of the frame (1), the pressure plate (9) covering the surface of the movable groove; an upper fixing hole (10) is formed on the pressure plate (9), and a lower fixing hole (11) is formed on the bottom wall of the movable groove; The extension frame (4) is provided with a movable hole (12), and an insertion rod (13) which cooperates with the upper fixing hole (10) and the lower fixing hole (11) is vertically slidably inserted into the movable hole (12).

3. The length-adjustable trailer chassis according to claim 2, characterized in that: The locking mechanism comprises a fixed arc plate (14) and a movable arc plate (15); the fixed arc plate (14) is fixedly mounted on an end of the support rod (7) away from the mounting rod (6); and the movable arc plate (15) is detachably mounted on the fixed arc plate (14) by means of bolts.

4. The length-adjustable trailer chassis according to claim 3, characterized in that: The extension frame (4) is provided with a cavity (16) filled with lubricating oil, a hole (17) communicating with the movable hole (12) is provided on the side wall of the cavity (16), and an extrusion mechanism for mixing the lubricating oil is provided on the extension frame (4).

5. The length-adjustable trailer chassis according to claim 4, characterized in that: The extrusion mechanism comprises a push plate (18) vertically slidably mounted on the side wall of the cavity (16); the push plate (18) and the hole (17) are located on the side wall on the same side of the cavity (16); a baffle (19) is fixedly mounted on the top wall of the push plate (18) away from the hole (17); both ends of the baffle (19) and the push plate (18) are in contact with the side wall of the cavity (16); a memory alloy wire (20) is installed between the push plate (18) and the bottom wall of the cavity (16); and a heat conducting rod (21) fixedly connected to the memory alloy wire (20) is embedded on the side wall of the movable hole (12).

6. The length-adjustable trailer chassis according to claim 5, characterized in that: The hole (17) is in the shape of a truncated cone, and the diameter of the hole (17) gradually decreases as the distance between the hole and the insertion rod (13) decreases.

7. The length-adjustable trailer chassis according to claim 1, characterized in that: A spring (22) is installed between the movable groove and the extension frame (4).

8. The length-adjustable trailer chassis according to claim 6, characterized in that: The support rod (7) comprises a sleeve (701) and an extension rod (702); the sleeve (701) is rotatably sleeved on the mounting rod (6); the extension rod (702) is movably inserted into the sleeve (701); and the fixed arc plate (14) is fixedly mounted on the end of the extension rod (702); A telescopic rod (23) is fixedly installed in the sleeve (701), an output end of the telescopic rod (23) is fixedly connected to the extension rod (702), and a trigger mechanism for triggering the telescopic rod (23) to operate is provided on the vehicle frame (1).

9. The length-adjustable trailer caravan chassis according to claim 8, characterized in that: The trigger mechanism comprises an inner mounting groove and an outer mounting groove formed on the bottom wall of the extension frame (4), the inner mounting groove and the outer mounting groove being always located above the movable groove, and an inner distance measuring module (24) and an outer distance measuring module (25) being respectively disposed in the inner mounting groove and the outer mounting groove; a buffer pad (26) is mounted on both the top wall and the bottom wall of the extension frame (4), and a detection hole is disposed on the buffer pad (26) on the bottom wall of the extension frame (4); The frame (1) is provided with a calculation module (27), a comparison module (28) and a control module (29); The internal distance measurement module (24) and the external distance measurement module (25) simultaneously send the detected data to the calculation module (27); The calculation module (27) calculates the received data and sends the calculation result to the comparison module (28); The comparison module (28) sends the comparison result to the control module (29); The control module (29) is used to control the extension amount of the telescopic rod (23).

10. The length-adjustable trailer chassis according to claim 9, characterized in that: The calculation module (27) calculates the received data: Wherein, B is the difference between the data detected by the inner distance measurement module (24) and the data detected by the outer distance measurement module (25); d 内 The distance between the position of the inner distance measuring module (24) and the bottom wall of the movable groove detected by the inner distance measuring module (24); d 外 The distance between the position of the external distance measuring module (25) and the bottom wall of the movable groove detected by the external distance measuring module (25); The comparison module (28) compares the received data: When B=0, the control module (29) does not work; When B≠0, the control module (29) operates and the telescopic rod (23) extends.

Images