High-precision multi-degree-of-freedom adjustable bearing platform

Abstract

The utility model relates to the technical field of assembly production equipment, and discloses a high-precision multi-degree-of-freedom adjustable bearing platform which comprises a walking mechanism, the walking mechanism comprises a bottom frame assembly, and guide rail assemblies are arranged at the two ends of the bottom frame assembly; a transverse adjusting mechanism is arranged on the bottom frame assembly and comprises an adjusting frame assembly, roller assemblies are arranged at the two ends of the adjusting frame assembly, and the roller assemblies are matched with the guide rail assemblies respectively, so that the adjusting frame assembly moves on the guide rail assemblies; a lifting mechanism is arranged on the transverse adjusting mechanism and comprises two lifting assemblies. A rolling mechanism used for containing a workpiece is arranged on the lifting mechanism and comprises a driving wheel assembly and a driven wheel assembly, and the driving wheel assembly drives the driven wheel assembly to rotate through the workpiece. According to the utility model, the precision of the assembly equipment in the assembly process of the large-sized cylindrical part is effectively improved, the repeated adjustment process is reduced, the operation is simpler, more convenient and more flexible, the hoisting stability is ensured, and the equipment universality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of assembly production equipment, in particular to a high-precision multi-degree-of-freedom adjustable bearing platform. Background Art

[0002] In the field of modern industrial manufacturing, large cylindrical parts are widely used in key fields such as energy, chemical industry, shipbuilding, aerospace, etc., and often have the characteristics of large size, high precision and high quality requirements. Due to their large size and complex structure, the precision control and operation difficulty in the assembly process are extremely high, and often require the collaboration of multiple departments.

[0003] At present, when assembling some large cylindrical workpieces, the assembly requirements can only be met by repeatedly lifting and adjusting the roller frame in conjunction with a crane, or by designing special tooling. During lifting and assembly, the position of the roller frame needs to be adjusted repeatedly, and then the workpiece is lifted to the designated position by the crane. However, the lifting process is not stable enough, and its operation accuracy is not high. After lifting to the designated position, it cannot be well fixed, and may be offset by external forces. After the workpiece is lifted onto the roller frame, in order to ensure that the contact between the roller frame and the cylindrical part is tight and uniform, and to avoid shaking or offset during the lifting process, the cylindrical part can only be adjusted axially, and the adjustment freedom is relatively single. The design of special tooling requires additional personnel, time and materials, and the loading and unloading of tooling is usually troublesome, difficult to operate, and not very versatile, which makes the existing large cylindrical parts have low adjustment accuracy during assembly, difficult to operate, and low assembly efficiency.

[0004] Therefore, in order to solve the problems that the assembly equipment of large cylindrical workpieces has low precision during the assembly process, needs repeated adjustment, is unstable and prone to offset after lifting, and is not flexible enough in adjustment, a high-precision multi-degree-of-freedom adjustable bearing platform is now provided. Utility Model Content

[0005] The utility model aims to provide a high-precision multi-degree-of-freedom adjustable bearing platform to solve the problems in the prior art that large cylindrical workpieces are not accurately assembled, require repeated adjustments, are not stable enough after hoisting, and are not flexible enough to adjust, resulting in a time-consuming and labor-intensive assembly process.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a high-precision multi-degree-of-freedom adjustable bearing platform, which realizes multi-degree-of-freedom adjustment by rotating horizontally left and right, vertically up and down, and forward and reverse directions. It can adjust the workpiece more flexibly, meet most workpiece assembly needs, improve the versatility of the equipment, and also improve the accuracy and stability of the adjustment, thereby improving assembly efficiency. Specifically, it includes a bearing platform electrically connected to the control cabinet, the bearing platform includes a walking mechanism, the walking mechanism includes a chassis component, guide rail assemblies are respectively provided at both ends of the chassis component, a sensor limit device is provided on the guide rail assembly, and the sensor limit device is electrically connected to the control cabinet; a lateral adjustment mechanism is provided on the chassis component, and the sensor limit device controls the moving range of the lateral adjustment mechanism; the lateral adjustment mechanism includes an adjustment frame component, roller assemblies are respectively provided at both ends of the adjustment frame component, and the roller assemblies cooperate with the guide rail assemblies respectively to make the adjustment frame component move on the guide rail assembly; a lifting mechanism is provided on the lateral adjustment mechanism, and the lifting mechanism includes two groups of lifting assemblies and linkage assemblies respectively connected to the two groups of lifting assemblies; a rolling mechanism for placing a workpiece is provided on the lifting mechanism, and the rolling angle of the rolling mechanism is 360°, and the rolling mechanism includes a driving wheel assembly and a driven wheel assembly, and the driving wheel assembly drives the driven wheel assembly to rotate through the workpiece.

[0007] The principles and advantages of this solution are:

[0008] The primary difficulty in assembling large cylindrical parts is precision control. Due to their huge size, factors such as slight deformation, temperature changes, and material stress of cylindrical parts may have a significant impact on assembly accuracy. In addition to ensuring the stability and safety of the operation, the comfort and efficiency of the operator must also be considered during the assembly process to avoid long-term heavy physical labor that may cause safety hazards to the operator.

[0009] In order to improve assembly efficiency, ensure assembly stability while reducing operational difficulty, simplify the operation process, and ensure the production safety of operators, this application adopts a multi-layer structure to set up an adjustment mechanism, using a walking mechanism to realize the movement of the entire load-bearing platform to ensure the platform's carrying capacity, using a lateral adjustment mechanism to achieve lateral displacement, and using a lifting mechanism to achieve longitudinal adjustment. Finally, a rolling mechanism is used to achieve forward and reverse multi-degree-of-freedom adjustment, and precise adjustment control of multiple angles is achieved directly on the load-bearing platform to meet most assembly scenarios. During assembly, the workpiece only needs to be hoisted onto the rolling mechanism, thereby simplifying the hoisting operation process, ensuring the operator's operating safety, and ensuring the overall stability of the platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The utility model is a structural schematic diagram of a high-precision multi-degree-of-freedom adjustable load-bearing platform for assembling workpieces.

[0011] Figure 2 The utility model is a structural schematic diagram of a high-precision multi-degree-of-freedom adjustable bearing platform.

[0012] Figure 3 The utility model is a schematic diagram of the structure of a walking mechanism of a high-precision multi-degree-of-freedom adjustable load-bearing platform.

[0013] Figure 4 The utility model is a schematic structural diagram of a guide rail assembly of a walking mechanism of a load-bearing platform with high precision and multiple degrees of freedom adjustment.

[0014] Figure 5 The utility model is a schematic structural diagram of a lateral adjustment mechanism of a load-bearing platform with high-precision and multi-degree-of-freedom adjustment.

[0015] Figure 6 It is a side view of a lateral adjustment mechanism of a load-bearing platform with high precision and multiple degrees of freedom adjustment according to the utility model.

[0016] Figure 7 The utility model is a schematic diagram of the dynamic structure of a lateral adjustment mechanism of a load-bearing platform with high precision and multiple degrees of freedom adjustment.

[0017] Figure 8 The utility model is a schematic diagram of the lifting mechanism structure of a high-precision multi-degree-of-freedom adjustable load-bearing platform.

[0018] Fig. 9 It is a front view of a lifting mechanism of a load-bearing platform with high precision and multi-degree-of-freedom adjustment according to the utility model.

[0019] Fig.10 The utility model is a structural schematic diagram of a rolling mechanism of a high-precision multi-degree-of-freedom adjustable load-bearing platform.

[0020] Fig.11 The utility model is a schematic structural diagram of the cooperation between a rolling mechanism of a high-precision multi-degree-of-freedom adjustable bearing platform and a workpiece.

[0021] Fig.12 The utility model is a structural schematic diagram of the use state of a high-precision multi-degree-of-freedom adjustable load-bearing platform. DETAILED DESCRIPTION

[0022] The following is further described in detail through specific implementation methods:

[0023] In the accompanying drawings: carrying platform 1, walking mechanism 2, chassis assembly 20, guide rail assembly 21, plane guide rail 201, V-shaped guide rail 202, sensor limit device 22, U-shaped frame 23, wheel assembly 24, lateral adjustment mechanism 3, adjustment frame assembly 30, roller assembly 31, plane roller 301, V-shaped roller 302, adjustment motor 32, ball screw 33, ball screw nut 34, lifting mechanism 4, lifting assembly 41, elevator 401, linkage assembly 42, transmission shaft 402, large and small synchronous wheels 403, longitudinal limit assembly 43, lifting motor 45, rolling mechanism 5, rolling frame assembly 501, driving wheel assembly 51, driven wheel assembly 52, parking brake mechanism 10, workpiece 12.

[0024] Embodiment 1

[0025] This embodiment is basically as shown in the attached Figure 1 As shown, a high-precision multi-degree-of-freedom adjustable bearing platform in this embodiment provides a more universal movable and high-degree-of-freedom assembly platform for workpieces with a diameter range of 740mm-6000mm and a weight of less than 15t. It can meet most assembly scenarios through motor control and adjustment, reduce the difficulty of workpiece assembly, and ensure the stability of workpiece assembly. At the same time, in this embodiment, for workpieces that are too long and weigh more than 15t, multiple bearing platforms can be used in combination in the axial direction of the workpiece. Specifically, it includes a control cabinet, and a bearing platform 1 electrically connected to the control cabinet, combined with the attached Figure 2 As shown, the carrying platform 1 includes a walking mechanism 2 with an overall rectangular structure, a lateral adjustment mechanism 3 that can move laterally is installed on the walking mechanism 2, a lifting mechanism 4 that can move up and down is installed on the lateral adjustment mechanism 3, and a rolling mechanism 5 that can rotate with multiple degrees of freedom is installed on the lifting mechanism 4. The rolling mechanism 5 is used to place the workpiece 12.

[0026] As attached Figure 3 As shown, the walking mechanism 2 includes a chassis component 20, and a wheel component 24 is installed below the chassis component 20 by bolts to ensure that the carrying capacity of the platform of the walking mechanism 2 meets the workpiece assembly requirements. In this embodiment, the wheel component 24 includes four wheel groups, which are respectively installed at the four corners of the chassis component 20 through wheel seats, and are connected to the parking brake mechanism 10 to control the operation of the wheel component 24. The wheel component 24 can ensure that the bearing platform 1 can travel straight on the standard track, and the parking brake mechanism 10 adopts a manual mode to ensure that the braking is stable and reliable when the entire equipment stops moving.

[0027] Combined with Figure 4 As shown, guide rail components 21 are fixedly installed at both ends of the upper surface of the bottom frame component 20 through hexagonal nuts. Figure 3As shown, the guide rail assembly 21 includes two groups of planar guide rails 201 and two groups of V-shaped guide rails 202, wherein the planar guide rails 201 and the V-shaped guide rails 202 are arranged on both sides of the chassis assembly 20 relatively, and are respectively located at the four corners of the chassis assembly 20. In this embodiment, the guide rail assembly 21 adopts a heavy-duty guide rail, and its length is adjusted and set according to the platform moving distance, and can also be set to a fixed length according to demand, which is not limited in this embodiment. At the same time, in this embodiment, the planar guide rail 201 is a guide rail with an overall rectangular structure, which has a limiting function through the rectangular structure, and the V-shaped guide rail 202 is a guide rail with an overall trapezoidal structure. The use of a trapezoidal structure can provide a certain degree of freedom, avoiding the situation where the planar guide rails on both sides are easily stuck, and at the same time avoiding the situation where the V-shaped guide rails have poor limiting effects and are easy to jump. By combining the planar guide rails and the V-shaped guide rails, both the limiting stability can be guaranteed and the adjustment freedom can be provided, so as to achieve a flexible and stable effect.

[0028] In this embodiment, the guide rail assembly 21 further includes a U-shaped frame 23 installed on the outside of the guide rail. The U-shaped frame 23 includes two frames, which are respectively installed on both sides of the base frame assembly 20. A sensor limit device 22 is installed on a hole on the inner side of the U-shaped frame 23 facing the center of the base frame assembly 20. The sensor limit device 22 is electrically connected to the control cabinet. Figure 5 As shown, a lateral adjustment mechanism 3 is installed between the U-shaped frames 23 on both sides. The lateral adjustment mechanism 3 can move laterally on the guide rail assembly 21, thereby moving laterally in the U-shaped frame 23, and the lateral movement range is controlled by the sensor limit device 22 in the U-shaped frame 23. When the lateral adjustment mechanism 3 moves laterally to the specified position, the sensor signal is triggered, and the control cabinet controls the motor to cut off power to achieve limiting, thereby limiting the lateral displacement of the lateral adjustment mechanism 3 within the travel range, thereby ensuring the accuracy and stability of the adjustment.

[0029] In this embodiment, as shown in the attached Figure 6As shown, the lateral adjustment mechanism 3 includes an adjustment frame assembly 30, and roller assemblies 31 are respectively installed below the two ends of the adjustment frame assembly 30. The roller assemblies 31 are respectively arranged above the guide rail assembly 21, and slide on the guide rail assembly 21 to make the adjustment frame assembly 30 move left and right on the guide rail assembly 21. In this embodiment, the roller assembly 31 includes two groups of plane rollers 301 and two groups of V-shaped rollers 302. The plane rollers 301 are movably arranged on the plane guide rail 201, and the V-shaped rollers 302 are movably arranged on the V-shaped guide rail 202. The plane rollers 301 are two groups of rollers arranged horizontally, each group of rollers includes two plane rollers arranged horizontally relatively, so that the rolling surfaces of the plane rollers directly slide in contact with the upper surface of the plane guide rail 201 to achieve limited sliding; the V-shaped rollers 302 are two groups of rollers arranged relatively tilted to form a V-shaped structure, each group of rollers includes two inclined rollers arranged relatively tilted to form a V-shaped structure, so that the relative rolling surfaces of the inclined rollers slide in contact with the two side surfaces of the V-shaped guide rail 202 to achieve adjustable sliding. At the same time, in this embodiment, combined with the attached Figure 5 and attached Figure 7 As shown, the lateral adjustment mechanism 3 also includes an adjustment motor 32 installed at the bottom of the adjustment frame assembly 30, and an electrical control mechanism connected to the adjustment motor 32. The electrical control mechanism is integrated in the control cabinet, and the motor operation is accurately controlled by the control cabinet to control the line speed within 0-250mm / min (stepless frequency conversion speed regulation) to achieve precise control. Figure 7 As shown, the adjustment motor 32 is also connected to a reducer and a ball screw 33. Bearing seats are installed at both ends of the ball screw 33 to ensure the stability of operation. A ball screw nut 34 is installed on the ball screw 33. One end of the ball screw nut 34 is installed on the adjustment frame assembly 30. The motor operation is controlled by an electrical control mechanism to drive the ball screw 33 to rotate. The ball screw nut 34 converts the rotational motion into linear motion, driving the adjustment frame assembly 30 to move laterally on the guide rail assembly 21, thereby realizing the lateral movement adjustment of the lateral adjustment mechanism 3.

[0030] As attached Figure 8 As shown, a lifting mechanism 4 is provided on the lateral adjustment mechanism 3, and the lifting mechanism 4 includes two groups of lifting components 41 and linkage components 42 respectively connected to the two groups of lifting components 41. Fig. 9 As shown, the lifting assembly 41 includes a lift 401 connected to an electrical control mechanism, and a lifting motor 45 is provided at the bottom of the lifting mechanism 4. Figure 6As shown, the lifting motor 45 is installed at the bottom of the chassis component 20, and the operation of the lifting motor 45 is controlled by the electrical control mechanism to realize the rise or fall adjustment of the elevator 401, and the linear speed of the lifting motor 45 is controlled at 0-250mm / min (stepless frequency conversion speed regulation) to achieve precise control. The linkage component 42 includes a transmission shaft 402 connected to the two groups of elevators 401 at both ends, and large and small synchronous wheels 403 are installed on the transmission shaft 402. The large and small synchronous wheels 403 are connected to the lifting motor 45 and drive the transmission shaft 402 to rotate, ensuring that the two groups of elevators 401 are lifted and lowered synchronously, improving the adjustment accuracy and ensuring the consistency of the adjustment. At the same time, the rotation speed of the lifting motor 45 can be reduced by the large and small synchronous wheels 403 to avoid excessive lifting speed and improve the control accuracy and stability. In this embodiment, a variable frequency motor can also be used to control the lifting speed.

[0031] A longitudinal limit assembly 43 is also installed on the lifting mechanism 4 to control the lifting travel range of the lifting mechanism 4. In this embodiment, the longitudinal limit assembly 43 is a block installed at the bottom of the rotating screw rod of the elevator 401, which realizes the mechanical limitation of the up and down travel range of the elevator and ensures the adjustment accuracy.

[0032] A rolling mechanism 5 for placing the workpiece 12 is installed above the lifting mechanism 4. Fig.10 As shown, the rolling mechanism 5 includes a rolling frame assembly 501, which is installed on the upper end of the elevator 401 through a connecting plate, and the rolling mechanism 5 is driven to move up and down by the lifting mechanism 4. A driving wheel assembly 51 and a driven wheel assembly 52 are installed on the rolling frame assembly 501. The driving wheel assembly 51 is arranged at one end of the rolling frame assembly 501, and the driven wheel assembly 52 is arranged at the other end of the rolling frame assembly 502. The distance between the driving wheel assembly 51 and the driven wheel assembly 52 is set to 450-1400mm. In this embodiment, the distance between the driven wheel assemblies can be adjusted within a range according to the size of the workpiece. The driving wheel assembly 51 rotates, driving the workpiece 12 to rotate and thereby driving the driven wheel assembly 52 to rotate. In this embodiment, the rolling angle of the rolling mechanism 5 is 360°, the diameter range of the supported workpiece 12 is 740mm-6000mm, and the linear speed is controlled at 0-500mm / min (stepless frequency conversion speed regulation), realizing precise control and multi-degree-of-freedom angle adjustment.

[0033] Combined with Fig.11 As shown, the driving wheel assembly 51 includes two driving wheels arranged side by side, the two driving wheels are connected by a first coupling, and the motor drives the driving wheels to roll through the coupling. The driven wheel assembly 52 includes two driven wheels arranged side by side, the two driven wheels are arranged opposite to the two driving wheels, and the two driven wheels are connected by a second coupling. The two driven wheels roll with the workpiece 12. In this embodiment, the driving wheel and the driven wheel are both rollers with a hard rubber surface to avoid damage to the workpiece 12.

[0034] The specific implementation process is as follows:

[0035] As attached Figure 1 To Attachment Fig.12 As shown, the docking and assembly work of a cylindrical part with a diameter of 2000mm, a height of 1800mm and a weight of 2t. The cylindrical part is suspended on the rolling mechanism 5 of the bearing platform 1 in this embodiment, so that the cylindrical part is placed between the driving wheel assembly 51 and the driven wheel assembly 52. ​​The cylindrical part is transported to the specified position by the walking mechanism 2, and braked by the parking brake mechanism 10 to ensure stability. Connect the cable between the control cabinet and the bearing platform 1, select the operation mode, and select the operation mode according to the operation requirements. The operation mode includes lateral left shift, lateral right shift, rise, fall, roll forward and roll reverse. The adjustment and alignment of the workpiece is achieved through the combination of multiple degrees of freedom, ensuring the accuracy of the position of the cylindrical part and reducing the difficulty of operation. Specifically, when assembling the cylindrical part, first select to adjust the lifting mechanism 4 to reach a predetermined height, then adjust the lateral adjustment mechanism 3 to make left and right fine adjustments, so that the cylindrical part is aligned with the assembly position, and finally adjust the rolling mechanism 5, screw the cylindrical part in, and complete the assembly.

[0036] In this embodiment, the workpiece is placed on the rolling mechanism 5 and the workpiece can be rotated by the active wheel rolling, so that the multi-axis and multi-angle adjustment of the workpiece can be realized, and the adjustment freedom is improved. The roller assembly 31 is driven by the motor to move laterally on the guide rail assembly 21 to realize the lateral movement of the workpiece. The lifting mechanism 4 drives the workpiece up and down, so that the workpiece can have a high degree of adjustment freedom on the bearing platform 1, while ensuring the stability and accuracy of the adjustment, thereby improving the applicability and versatility of assembly, meeting most assembly requirements, without frequently changing the assembly platform, reducing the difficulty and complexity of operation, and improving convenience. At the same time, the wheel assembly 24 of the walking mechanism 2 can place the bearing platform 1 on the rail and run stably on the rail to ensure stability.

[0037] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A high-precision multi-degree-of-freedom adjustable bearing platform, characterized in that: It includes a bearing platform electrically connected to the control cabinet, the bearing platform includes a walking mechanism, the walking mechanism includes a chassis component, guide rail assemblies are respectively provided at both ends of the chassis component, a sensor limit device is provided on the guide rail assembly, and the sensor limit device is electrically connected to the control cabinet; a lateral adjustment mechanism is provided on the chassis component, and the sensor limit device controls the moving range of the lateral adjustment mechanism; the lateral adjustment mechanism includes an adjustment frame component, roller assemblies are respectively provided at both ends of the adjustment frame component, and the roller assemblies cooperate with the guide rail assemblies respectively to make the adjustment frame component move on the guide rail assembly; a lifting mechanism is provided on the lateral adjustment mechanism, and the lifting mechanism includes two groups of lifting assemblies and linkage assemblies respectively connected to the two groups of lifting assemblies; a rolling mechanism for placing a workpiece is provided on the lifting mechanism, and the rolling angle of the rolling mechanism is 360°, and the rolling mechanism includes a driving wheel assembly and a driven wheel assembly, and the driving wheel assembly drives the driven wheel assembly to rotate through the workpiece.

2. A high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: The guide rail assembly comprises two groups of planar guide rails and two groups of V-shaped guide rails. The planar guide rails and the V-shaped guide rails are arranged opposite to each other and are respectively arranged at the four corners of the base frame.

3. A high-precision multi-degree-of-freedom adjustable bearing platform according to claim 2, characterized in that: The roller assembly comprises two groups of plane rollers and two groups of V-shaped rollers. The plane rollers are movably arranged on the plane guide rails, and the V-shaped rollers are movably arranged on the V-shaped guide rails.

4. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: The lifting assembly includes a lift connected to an electrical control mechanism; the linkage assembly includes a transmission shaft connected to the lift, on which are arranged large and small synchronous wheels, which are connected to a motor and drive the transmission shaft to rotate.

5. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: The rolling mechanism includes a rolling frame component, which is arranged on the lifting mechanism; the driving wheel assembly is arranged at one end of the rolling frame component, and the driven wheel assembly is arranged at the other end of the rolling frame component; the distance between the driving wheel assembly and the driven wheel assembly is 450-1400mm.

6. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 2, characterized in that: The guide rail assembly includes a U-shaped frame arranged on the outside of the guide rail, and the U-shaped frame is arranged on the base frame assembly; the sensor limit device is arranged on the inside of the U-shaped frame to monitor the lateral movement distance of the roller assembly.

7. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 3, characterized in that: The plane rollers are two groups of rollers arranged horizontally, each group including two plane rollers arranged oppositely; the V-shaped rollers are two groups of rollers arranged to form a V-shaped structure at an angle relative to each other, each group including two inclined rollers arranged to be inclined relative to each other.

8. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: The driving wheel assembly includes two driving wheels arranged side by side, and the two driving wheels are connected through a first coupling; the driven wheel assembly includes two driven wheels arranged side by side, the two driven wheels are arranged opposite to the two driving wheels, and the two driven wheels are connected through a second coupling.

9. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: The lifting mechanism is also provided with a longitudinal limit assembly to control the lifting travel range of the lifting mechanism.

10. The high-precision multi-degree-of-freedom adjustable bearing platform according to claim 1, characterized in that: A wheel component is also provided below the underframe component.

Images