CN104354715B - A kind of automobile case track conveying device - Google Patents

Abstract

The invention discloses an automobile body rail transportation device, which comprises a front wheel frame, a rear wheel frame and a balance bar. shaped wheels; the balance bar has two, respectively set along the direction of the track, the balance bar can achieve a certain angle of elastic bending deformation, the angle is determined by the length between the two connection points of the balance bar and the two tracks at the same position The maximum height difference is determined; the two ends of the front wheel frame and the rear wheel frame are respectively provided with a support column on the plane, and a compression spring is respectively arranged between the support column and the front wheel frame and the rear wheel frame. The top of the support column is respectively provided with a U-shaped bracket with an upward opening, and the U-shaped groove of the U-shaped bracket is matched with the bottom beam of the car shell; derailment accident.

Description

A kind of car shell rail transportation device

technical field

The invention relates to a transportation device, in particular to an automobile body rail transportation device.

Background technique

The traditional automobile body rail transportation device includes a rigid underframe for carrying the automobile body. The bottom of the underframe is provided with four rectangularly arranged T-shaped wheels that are respectively matched with two rails. When walking, the flanges of the T-shaped wheels block the rails on both sides to prevent the derailment of the car body rail transport device. Because the assembly process of passenger cars is relatively complicated and needs to go through multiple processes, the track of the car body rail transport device is correspondingly long. After long-term use of the track, it is easy for two tracks to be in the same position due to the wear and tear of the track surface and partial shedding. There is a height difference, and when the car body rail transport device passes by here, since the three T-shaped wheels can form a plane, and the underframe is rigid, there must be a wheel suspended in the absence of external force. , if the suspended height is greater than the flange of the T-shaped wheel, a derailment accident may occur. Although these track defects can be repaired or replaced when the track is regularly inspected, there are still hidden dangers that are not conducive to safe production.

Contents of the invention

The technical problem to be solved by the present invention is to provide an automobile body rail transportation device which can prevent the vehicle body rail transportation device from derailing due to the suspension of T-shaped wheels.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A rail transportation device for automobile shells, comprising front wheel frames and rear wheel frames arranged along the track direction and at least one elastically deformable balance bar connecting the front wheel frames and the rear wheel frames, the bottom of the front wheel frame is provided with Two T-shaped wheels respectively matched with the two tracks, and two T-shaped wheels respectively matched with the two tracks are arranged at the bottom of the rear wheel frame; A support column is respectively arranged on the plane, and compression springs are respectively arranged between the support column and the corresponding front wheel frame and the rear wheel frame. A U-shaped bracket with an upward opening is respectively arranged on the top of the support column. The U-shaped groove of the bracket matches with the bottom beam of the car shell.

The two ends of the front wheel frame and the rear wheel frame are respectively symmetrically provided with a vertical standpipe, the compression spring is vertically arranged in the standpipe, the lower end of the support column is inserted into the standpipe, and the bottom surface of the support column is in contact with the compression spring. The top surfaces of the springs are against each other.

A rail transportation device for automobile shells, comprising a front wheel frame and a rear wheel frame arranged along the track direction and at least one elastically deformable balance bar connecting the front wheel frame and the rear wheel frame, the front wheel frame and the rear wheel frame Two wheel brackets corresponding to the two rails are arranged to slide up and down at the bottom of the frame respectively, and the lower part of the wheel bracket is rotatably connected with T-shaped wheels respectively matched with the corresponding rails; the upper parts of the two wheel brackets at the bottom of the front wheel frame The planes are respectively vertically provided with a support column that passes upwards from the upper plane of the front wheel frame, and the upper planes of the two wheel brackets at the bottom of the rear wheel frame are also vertically provided with a support column that passes upwards from the upper plane of the rear wheel frame. The support column can follow the corresponding wheel bracket and slide up and down relative to the front wheel frame or the rear wheel frame respectively. Compression springs are respectively arranged between the support column and the corresponding wheel bracket, and the top ends of the support column are respectively arranged There is an upward U-shaped support block with an opening, and the U-shaped groove of the U-shaped support block matches the bottom beam of the car shell.

There are two balance bars, one end of the balance bar is respectively connected to the front wheel frame by rotation, and the other end is respectively slidably connected to the rear wheel frame along the track direction and can be locked with the rear wheel frame; or the two ends of the balance bar are respectively along the The track direction is slidingly connected on the front wheel frame and the rear wheel frame, and can be locked with the front wheel frame and the rear wheel frame.

A tooth rack is symmetrically and axially fixed on the two side walls of the sliding connection between the balance bar and the front wheel frame and the rear wheel frame respectively, and a bottom plate is respectively symmetrically arranged at both ends of the front wheel frame and the rear wheel frame, and the bottom plate Side plates are vertically arranged on both sides; or a tooth rack is symmetrically and axially fixed on the two side walls of the sliding connection between the balance bar and the rear wheel frame, and a rack is symmetrically arranged at both ends of the rear wheel frame. Bottom plate, side plates are vertically arranged on both sides of the bottom plate; the upper surface of the bottom plate is provided with a through groove matching the part of the balance bar below the rack, the balance bar is slidably arranged in the through groove, and the rack just It is lapped on the upper surface of the bottom plate, and there are two gears meshing with the two racks between the two side plates. The two gears are connected in series on the same transmission shaft, and the two ends of the transmission shaft are respectively connected to the two On the side plate, one end of the transmission shaft protrudes from the corresponding side plate, and a hand wheel is fixedly connected to the extended end, and a second locking bolt is threaded on the side plate corresponding to the other end of the transmission shaft. The head of the locking bolt can be against the side wall of the corresponding gear.

A connecting shaft is fixedly connected between two opposite ends of the two transmission shafts.

A driven sprocket is fixedly sleeved in the middle of the connecting shaft, a motor is arranged at the bottom of the rear wheel frame, and a driving sprocket is fixedly sleeved on the output shaft of the reducer, and the driven sprocket passes through The chain is connected with the drive sprocket.

The two ends of the front wheel frame and the rear wheel frame that are slidably connected with the balance bar are respectively symmetrically provided with a sleeve that can pass through the balance bar. One end of the balance bar is respectively inserted into the sleeve on the front wheel frame. One end is respectively inserted into the bushing on the rear wheel frame; or the two ends of the rear wheel frame which are slidingly connected with the balance bar are respectively provided with a bushing which can pass through the balance bar, and one end of the balance bar is inserted in the rear In the casing on the wheel frame, the other end is rotatably connected to the front wheel frame; at least one first locking bolt is radially threaded on the wall of the casing, and the head of the first locking bolt can be connected to the inside of the casing. balance bar.

A vertical standpipe is respectively arranged on the upper plane of the wheel bracket, the compression spring is vertically arranged in the standpipe, the lower end of the support column is inserted into the standpipe, and the bottom surface of the support column is offset against the top surface of the compression spring.

The beneficial effects of the present invention are: when the automobile body rail transport device travels through the place where there is a height difference between the two rails, the compression spring can press the T-shaped wheel on the rail, so that the T-shaped wheel and the rail always keep in contact, preventing the T-shaped wheel from Suspended in the air, derailed from the track to cause a derailment accident of the car body rail transportation device. At the same time, the spring can also play a shockproof role and can effectively absorb the vibration transmitted to the car body by the wheels of the car body rail transportation device during transportation;

The invention can also adjust the distance between the front wheel frame and the rear wheel frame, can adapt to the transportation of automobile shells of various models, and saves capital investment and workshop space.

Description of drawings

Fig. 1 is a state diagram of the first embodiment of the present invention at a position with a height difference on the track;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the A-A view of Fig. 2;

Fig. 4 is a structural diagram of an improved solution of the first specific embodiment of the present invention;

Figure 5 is a top view of Figure 4;

Fig. 6 is a state diagram of the second embodiment of the present invention at a position with a height difference on the track.

In the accompanying drawings: 1, T-shaped wheel, 2, front wheel frame, 3, rear wheel frame, 4, balance bar, 5, support column, 6, compression spring, 7, rack, 81, bottom plate, 82, side plate , 9, through slot, 10, gear, 11, transmission shaft, 12, hand wheel, 13, U-shaped bracket, 14, bushing, 15, first locking bolt, 16, connecting shaft, 17, driven chain Wheel, 18, motor, 19, driving sprocket, 20, chain, 21, standpipe, 22, track, 23, wheel support, 24, the second locking bolt.

detailed description

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 is the first kind of specific embodiment of the present invention, and as shown in the figure, a kind of automobile body rail transportation device, comprises front wheel frame 2 and rear wheel frame 3 that are arranged along track 22 directions and at least one connects front wheel frame 2 and the balance bar 4 with elastic deformation of the rear wheel frame 3, the bottom of the front wheel frame 2 is provided with two T-shaped wheels 1 respectively matched with two rails 22, and the bottom of the rear wheel frame 3 is also provided with Two T-shaped wheels 1 matched with two rails 22 respectively; the balance bar 4 can realize elastic bending deformation at a certain angle, and the angle is determined by the length between the two connection points of the balance bar 4 and the distance between the two rails 22 The maximum height difference at the same position is determined; the upper planes at both ends of the front wheel frame 2 and the rear wheel frame 3 are respectively provided with a support column 5, and the support column 5 is connected with the corresponding front wheel frame 2 and the rear wheel frame respectively. 3 are respectively provided with compression springs 6, and the top of the support column 5 is respectively provided with a U-shaped bracket 13 with an opening upward, and the U-shaped groove of the U-shaped bracket 13 is matched with the bottom beam of the vehicle shell.

Since the bottom of the support column 5 is provided with a compression spring 6, when the automobile body rail transport device travels through the position where the rails 22 on both sides have a height difference, the compression spring 6 above the suspended T-shaped wheel 1 will push the T-shaped wheel 1 downward. Correspondingly, the balance bar 4 will be bent and deformed until the T-shaped wheel 1 contacts the track 22, and the support column 5 can still make the U-shaped bracket 13 on the top of the support column 5 and the car shell due to the elastic force of the compression spring 6. Bottom beams offset.

Fig. 6 is the second kind of specific embodiment of the present invention, as shown in the figure, a kind of automobile body rail transportation device, comprises front wheel frame 2 and rear wheel frame 3 that are arranged along track 22 directions and at least one connects front wheel The balance bar 4 with elastic deformation of the frame 2 and the rear wheel frame 3, the bottoms of the front wheel frame 2 and the rear wheel frame 3 respectively slide up and down to be provided with two wheel brackets 23 corresponding to the two rails 22, and the wheel brackets 23 The lower part of the bottom is rotatably connected with T-shaped wheels 1 that are matched with the corresponding rails 22; Support column 5, the upper planes of the two wheel brackets 23 at the bottom of the rear wheel frame 3 are also vertically provided with a support column 5 that passes upwards from the upper plane of the rear wheel frame 3, and the support column 5 can follow the corresponding The wheel brackets 23 slide up and down relative to the front wheel frame 2 or the rear wheel frame 3 respectively, and compression springs 6 are respectively arranged between the support columns 5 and the corresponding wheel brackets 23, and an opening is respectively arranged at the top of the support columns 5 Upward U-shaped bracket 13, the U-shaped groove of U-shaped bracket 13 is matched with the bottom beam of the vehicle shell.

Since the wheel bracket 23 and the corresponding front wheel frame 2 and the rear wheel frame 3 are relatively slidingly connected up and down, when the automobile body rail transport device passes through the position where the rails 22 on both sides have a height difference, the above the suspended T-shaped wheel 1 The compression spring 6 will press the wheel bracket 23 downward, and the wheel bracket 23 will slide down relative to the front wheel frame 2 or the rear wheel frame 3 until the T-shaped wheel 1 contacts the track 22. In this process, the balance bar 4 is not deformed, and the U-shaped bracket 13 at the top of the support column 5 can still support the bottom beam of the car shell.

As shown in Figures 1 to 6, there are two balance poles 4, one end of the balance pole 4 is respectively connected to the front wheel frame 2 in rotation, and the other end is respectively slidably connected to the rear wheel frame 3 along the direction of the track 22 and can be connected to the rear wheel frame 3. The rear wheel frame 3 is locked; or the two ends of the balance bar 4 are slidably connected to the front wheel frame 2 and the rear wheel frame 3 along the direction of the track 22, and can be locked with the front wheel frame 2 and the rear wheel frame 3.

The distance between the front wheel frame 2 and the rear wheel frame 3 can be adjusted like this, which can adapt to the transportation of various types of automobile shells; one end of the balance bar 4 is rotationally connected with the front wheel frame 2. When the device passes through the position where there is a difference in height between the rails 22 on both sides, the torsion force received by the balance bar 4 is released through the rotating connection pair, so that only one bending moment is received, so that the balance bar 4 is bent and deformed.

As shown in Figures 1 to 3, the first specific implementation of the rail transport device for automobile shells, the two side walls of the sliding connection between the balance bar 4 and the front wheel frame 2 and the rear wheel frame 3 are symmetrical axially respectively. A rack 7 is fixedly arranged, and a bottom plate 81 is arranged symmetrically at both ends of the front wheel frame 2 and the rear wheel frame 3, and side plates 82 are vertically arranged on both sides of the bottom plate 81; or the balance bar 4 and the rear wheel frame A tooth rack 7 is symmetrically and axially fixed on the two side walls of the sliding joint of the wheel frame 3, respectively, and a bottom plate 81 is symmetrically arranged at both ends of the rear wheel frame 3, and side plates are vertically arranged on both sides of the bottom plate 81. 82; the upper surface of the bottom plate 81 is provided with a through groove 9 matching the part of the balance bar 4 below the rack 7, the balance bar 4 is slidably arranged in the through groove 9, and the rack 7 just overlaps the bottom plate 81 on the upper surface, two gears 10 respectively meshed with the two racks 7 are arranged between the two side plates 82, the two gears 10 are connected in series on the same transmission shaft 11, and the two ends of the transmission shaft 11 rotate respectively Connected to the two side plates 82, one end of the transmission shaft 11 protrudes from the corresponding side plate 82, and a hand wheel 12 is fixedly connected to the extended end, and the corresponding side plate 82 at the other end of the transmission shaft 11 is threaded with a second Two locking bolts 24 , the head of the second locking bolt 24 can abut against the side wall of the corresponding gear 10 .

The balance bar 4 connects the front wheel frame 2 and the rear wheel frame 3 through the gear 10 and the rack 7, or the balance bar 4 connects the rear wheel frame 3 through the gear 10 and the rack 7, so that the adjustment between the front wheel frame 2 and the rear wheel frame 3 The distance between them is more convenient and labor-saving.

As shown in FIG. 2 , a connecting shaft 16 is fixedly connected between two opposite ends of the two transmission shafts 11 . In this way, the relative movement between the two balance bars 4 and the rear wheel frame 3 can be synchronized, and the adjustment and measurement of the distance between the front wheel frame 2 and the rear wheel frame 3 can be saved twice Work on the parallelism of the front wheel frame 2 and the rear wheel frame 3.

As shown in Figure 2, a driven sprocket 17 is fixedly sleeved in the middle of the connecting shaft 16, a motor 18 is arranged at the bottom of the rear wheel frame 3, and a driving chain is fixedly sleeved on the output shaft of the reducer 18. The driven sprocket 17 is connected with the driving sprocket 19 through a chain 20 . Utilize motor 18 to drive gear 10 to rotate like this, thereby regulate the distance between front wheel frame 2 and rear wheel frame 3, not only convenient, but also labor-saving.

Fig. 4 and Fig. 5 show the improved scheme of the first specific embodiment of a rail transport device for automobile shells, in which the two ends of the front wheel frame 2 and the rear wheel frame 3 which are slidingly connected with the balance bar 4 are arranged symmetrically There is a sleeve 14 that can be passed through by the balance bar 4, one end of the balance bar 4 is respectively inserted in the sleeve 14 on the front wheel frame 2, and the other end is respectively inserted in the sleeve 14 on the rear wheel frame 3 Or, the two ends of the rear wheel frame 3 slidingly connected with the balance bar 4 are respectively provided with a sleeve 14 that can pass through the balance bar 4, and one end of the balance bar 4 is inserted into the rear wheel frame 3 In the casing 14, the other end is rotatably connected to the front wheel frame 2; on the pipe wall of the casing 14, at least one first locking bolt 15 is radially threaded, and the head of the first locking bolt 15 can be connected with the The balance bar 4 in the sleeve pipe 14 offsets.

Utilize the first locking bolt 15 radially arranged on the pipe wall of sleeve pipe 14 and sleeve pipe 14 to fix balance bar 4, loosen the two sleeve pipes 14 on the front wheel frame 2 and/or rear wheel frame 3. After the first locking bolt 15, the distance between the front wheel frame 2 and the rear wheel frame 3 can be adjusted. After the adjustment is completed, the first locking bolt 15 is tightened until the head of the bolt is in contact with the balance bar 4. The scheme is simple in structure and convenient to manufacture.

In the first specific embodiment of a rail transport device for automobile shells as shown in Figures 1 to 5, a vertical standpipe 21 is symmetrically arranged at both ends of the front wheel frame 2 and the rear wheel frame 3, respectively. The compression spring 6 is vertically arranged in the standpipe 21 , the lower end of the support column 5 is inserted into the standpipe 21 , and the bottom surface of the support column 5 is against the top surface of the compression spring 6 .

In the second specific embodiment of a rail transport device for automobile shells as shown in Figure 6, a vertical standpipe 21 is respectively arranged on the upper plane of the wheel bracket 23, and the compression spring 6 is vertically arranged on the standpipe 21 , the lower end of the support column 5 is inserted into the standpipe 21 , and the bottom surface of the support column 5 is against the top surface of the compression spring 6 .

After the standpipe 21 is added, the side bending of the compression spring 6 can be prevented. When there is a gap of 2 mm to 3 mm between the standpipe 21 and the support column 5, the support column 5 will not be tilted due to the up and down movement of the T-shaped wheel .

The working process of the present invention is: the first embodiment of the present invention shown in Fig. 1～Fig. The bottom beam of the car shell can be placed in the U-shaped bracket 13 at the top of the support column 5. The specific working process is to first loosen the second locking bolt 24, then start the motor 18 or turn the hand wheel, so that the gear 10 and the rack 8 are opposite to each other. Move until the center distance between the support column 5 on the front wheel frame 2 and the support column 5 on the rear wheel frame 3 meets the requirements, then tighten the second locking bolt 24, and then lift the car shell to the car shell track Slowly descend above the transport device, and at the same time adjust the horizontal position of the car shell, until finally the bottom beam of the car shell is placed in the U-shaped bracket 13 of the support column 5;

Then manpower promotes or pulls the automobile body rail transport device to move, when the automobile body rail transport device travels through the position where the rails 22 on both sides have a height difference, the compression spring 6 above the T-shaped wheel 1 that is suspended in the air with the rail 22 releases elastic force, so that The T-shaped wheel 1 moves downward until the track 22 contacts, and at the same time, the balance bar 4 undergoes elastic bending deformation, and the balance bar 4 rotates relative to the front wheel frame 2, and the support bar 4 is under the elastic force of the compression spring 6. The U-shaped bracket 13 is still against the bottom beam of the automobile shell. After the T-shaped wheel 1 passes through the track 22 with a height difference, the T-shaped wheel 1 moves upwards along the track 22, and the compression spring 6 returns to the compressed state, and the balance bar 4 Return to original state.

As shown in Fig. 4 and Fig. 5, the improvement scheme of the first specific embodiment of the present invention, its working process is, first loosen the first locking bolt 15 on the high pipe 14, then slide the front wheel along the direction of the balance bar 4 frame 2 and/or rear wheel frame 3 until the distance between the front wheel frame 2 and the rear wheel frame 3 meets the requirements for use, and then put the car shell on the rail transport device of the car shell, so that the bottom beam of the car shell is placed Into the U-shaped bracket 13 at the top of the support column 5, and then manually push or pull the car body rail transport device to move. The compression spring 6 above the T-shaped wheel 1 releases the elastic force, so that the T-shaped wheel 1 moves downwards so as to contact the track 22. At the same time, the balance bar 4 undergoes elastic bending deformation and torsional deformation. Next, the U-shaped support block 13 at its top is still against the bottom beam of the automobile shell. After the T-shaped wheel 1 passes through the track 22 with a height difference, the T-shaped wheel 1 moves upward along the track 22, and the compression spring 6 returns to the compressed state. state, the balance bar 4 returns to the original state.

The second specific embodiment of the present invention shown in Figure 6, its working process is, at first loosen the first locking bolt 15 on the high pipe 14, then slide the front wheel frame 2 and/or the rear along the direction of the balance bar 4 Wheel frame 3, until the distance between the front wheel frame 2 and the rear wheel frame 3 meets the requirements for use, then the car shell is placed on the car shell track transport device, so that the bottom beam of the car shell is placed on the top of the support column 5 In the U-shaped support block 13, then manpower promotes or pulls the automobile shell rail transport device to move, when the automobile shell rail transport device travels through the position where the rails 22 on both sides have a height difference, the compression spring on the top of the suspended T-shaped wheel 1 6 will press the wheel bracket 23 downward, and the wheel bracket 23 will slide down relative to the front wheel frame 2 or the rear wheel frame 3 until the T-shaped wheel 1 contacts the track 22. In this process, the balance beam 4 will not Bending deformation and torsional deformation occur, and the U-shaped bracket 13 at the top of the support column 5 can still be offset against the bottom beam of the car shell due to the elastic force of the compression spring 6 in the support column 5, thereby effectively preventing the vehicle shell rail transport device from being damaged Derailment caused by the suspension of T-shaped wheels.

Claims (9)

1. An automobile body rail transport device is characterized in that it comprises a front wheel frame (2) and a rear wheel frame (3) arranged along the track (22) direction and at least one connecting front wheel frame (2) and a rear wheel frame The balance bar (4) with elastic deformation of the wheel frame (3), the bottom of the front wheel frame (2) is provided with two T-shaped wheels (1) respectively matched with the two rails (22), the rear The bottom of the wheel frame (3) is also provided with two T-shaped wheels (1) that match the two rails (22) respectively; A support column (5) is provided, and compression springs (6) are respectively arranged between the support column (5) and the corresponding front wheel frame (2) and the rear wheel frame (3), and the support column (5) The top of the top is respectively provided with an upward U-shaped bracket (13) with an opening, and the U-shaped groove of the U-shaped bracket (13) cooperates with the bottom beam of the car shell. 2. A kind of automobile body rail transportation device according to claim 1, characterized in that, a vertical standpipe ( 21), the compression spring (6) is vertically arranged in the standpipe (21), the lower end of the support column (5) is inserted into the standpipe (21), and the bottom surface of the support column (5) is in contact with the compression spring ( 6) offset the top surface. 3. An automobile body rail transportation device, characterized in that it comprises front wheel frames (2) and rear wheel frames (3) arranged along the track (22) direction and at least one connecting front wheel frame (2) and rear wheel frames The balance bar (4) of the wheel frame (3) has elastic deformation, and the bottoms of the front wheel frame (2) and the rear wheel frame (3) slide up and down respectively and are provided with two corresponding to the two rails (22). Wheel brackets (23), the bottom of the wheel brackets (23) are rotatably connected with T-shaped wheels (1) that match the corresponding rails (22) respectively; two wheel brackets (23) at the bottom of the front wheel bracket (2) The upper plane of the front wheel frame (2) is vertically provided with a support column (5) that passes through the upper plane of the front wheel frame (2) respectively, and the upper planes of the two wheel brackets (23) at the bottom of the rear wheel frame (3) are also vertically respectively To be provided with a support column (5) that passes upwards out of the upper plane of the rear wheel frame (3), the support column (5) can follow the corresponding wheel bracket (23) respectively relative to the corresponding front wheel frame (2) or The rear wheel frame (3) slides up and down, and compression springs (6) are respectively arranged between the support columns (5) and the corresponding wheel brackets (23), and the tops of the support columns (5) are respectively provided with an opening upward U-shaped bracket (13), the U-shaped groove of the U-shaped bracket (13) is matched with the cross beam at the bottom of the car shell. 4. A kind of automobile body rail transportation device according to claim 1 or 3, characterized in that, the number of said balance poles (4) is two, and one end of the balance poles (4) is respectively connected to the front wheel on the frame (2), and the other ends are slidingly connected to the rear wheel frame (3) along the direction of the track (22) and can be locked with the rear wheel frame (3); or the two ends of the balance bar (4) are respectively along the track (22) ) direction sliding connection on the front wheel frame (2) and the rear wheel frame (3), and can be locked with the front wheel frame (2) and the rear wheel frame (3). 5. A kind of automobile body rail transportation device according to claim 4, characterized in that, the two side walls of the sliding connection between the balance bar (4) and the front wheel frame (2) and the rear wheel frame (3) A tooth bar (7) is arranged symmetrically and axially on the top respectively, and a bottom plate (81) is respectively symmetrically arranged at both ends of the front wheel frame (2) and the rear wheel frame (3), and the two sides of the bottom plate (81) are respectively vertical A side plate (82) is provided to the side plate (82); or a tooth rack (7) is respectively symmetrically and axially fixed on the two side walls of the sliding joint between the balance bar (4) and the rear wheel frame (3), and the rear wheel A bottom plate (81) is arranged symmetrically at both ends of the frame (3), and side plates (82) are vertically arranged on both sides of the bottom plate (81); The part below the rack (7) matches the through groove (9), the balance bar (4) is slidably arranged in the through groove (9), and the rack (7) just overlaps the upper surface of the bottom plate (81) , there are also two gears (10) meshing with the two racks (7) between the two side plates (82), the two gears (10) are connected in series on the same transmission shaft (11), and the transmission The two ends of the shaft (11) are rotatably connected to the side plates (82) respectively, and one end of the transmission shaft (11) protrudes from the corresponding side plate (82), and a hand wheel (12) is fixedly connected to the protruding end. ), the corresponding side plate (82) at the other end of the transmission shaft (11) is threadedly connected with a second locking bolt (24), and the head of the second locking bolt (24) can be connected with the corresponding gear (10) side walls against each other. 6 . The vehicle body rail transportation device according to claim 5 , characterized in that, a connecting shaft ( 16 ) is fixedly connected between two opposite ends of the two transmission shafts ( 11 ). 6 . 7. A kind of automobile body rail transportation device according to claim 6, characterized in that, a driven sprocket (17) is fixedly sleeved in the middle of the connecting shaft (16), and the rear wheel frame (3 ) bottom is provided with a motor (18), and a driving sprocket (19) is fixedly sleeved on the output shaft of the motor (18), and the driven sprocket (17) is connected with the driving sprocket by a chain (20) (19) CONNECTION. 8. A rail transportation device for automobile shells according to claim 4, characterized in that the two ends of the front wheel frame (2) and the rear wheel frame (3) which are slidingly connected with the balance bar (4) are respectively symmetrical A sleeve (14) that can pass through the balance bar (4) is provided, one end of the balance bar (4) is respectively inserted into the sleeve (14) on the front wheel frame (2), and the other end is respectively inserted into the In the sleeve pipe (14) on the rear wheel frame (3); or, the two ends of the rear wheel frame (3) that are slidably connected with the balance bar (4) are respectively provided with a One end of the balance bar (4) is inserted into the sleeve (14) on the rear wheel frame (3), and the other end is rotatably connected to the front wheel frame (2); the sleeve At least one first locking bolt (15) is radially threaded on the pipe wall of the pipe (14), and the head of the first locking bolt (15) can offset the balance bar (4) in the casing (14) . 9. A kind of automobile body rail transportation device according to claim 3, characterized in that, a vertical standpipe (21) is respectively arranged on the upper plane of the wheel bracket (23), and the compression spring (6 ) is vertically arranged in the standpipe (21), the lower end of the support column (5) is inserted in the standpipe (21), and the bottom surface of the support column (5) is against the top surface of the compression spring (6).