A cab lifting device, a commercial vehicle, and a cab lifting method thereof.

Abstract

This invention provides a cab lifting device, a commercial vehicle, and a cab lifting method thereof, relating to the field of cab lifting. The solution is as follows: the lifting cylinder body is rotatably mounted on the vehicle frame; the piston rod of the lifting cylinder is connected to the cab crossbeam; the upper end of a limiting plate is hinged to the piston rod of the lifting cylinder; the limiting plate is located on one side of the lifting cylinder; the limiting plate is provided with a communicating guide groove and a limiting groove; the limiting groove is located below the guide groove; a limiting shaft is provided at the upper end of the lifting cylinder body. When the cab tilts and returns to its original position, the guide groove and the limiting groove can slide relative to the limiting shaft. When the cab falls back during the lifting process, the limiting shaft can abut against the upper end of the limiting groove to prevent the cab from falling back; when the cab falls after being lifted to its final position, the limiting shaft can abut against the lower end of the limiting groove to prevent the cab from excessively tilting. This invention can improve the safety of cab tilting and avoid cab falling and tilting back when the lifting cylinder fails.

Description

Technical Field

[0001] This invention relates to the field of cab lifting, and more particularly to a cab lifting device, a commercial vehicle, and a cab lifting method thereof. Background Technology

[0002] Currently, the tilting mechanism for medium and heavy-duty commercial vehicle cabs is mainly hydraulic, which offers advantages such as high support force and reliability. However, during normal vehicle operation, the cab will bounce up and down due to varying road surface conditions. Since the lifting hydraulic cylinder is rigidly connected to the cab, the impact from these bumps and vibrations during vehicle movement can easily damage the lifting hydraulic cylinder or the cab crossbeams.

[0003] In the prior art, the patent application publication number is CN 109941360 Chinese invention patent application A discloses a vehicle hydraulic cylinder tilting mechanical floating assembly, including a bracket assembly, a swing arm assembly, and a hydraulic cylinder assembly. The bracket assembly is rotatably connected to the swing arm assembly, and the swing arm assembly is rotatably connected to the hydraulic cylinder assembly. The bracket assembly includes a bracket, a tilting limit block, two limit sleeves, three bolts, and three nuts. The two ends of the tilting limit block are welded into positioning grooves on both sides of the bracket. Two bolts pass through through holes on the bracket, are fitted into the limit sleeves, and are tightened by nuts. The bracket and the swing arm assembly are connected by another bolt. When the vehicle is in normal operation, the assembly can allow the cab to move up and down normally while ensuring that the hydraulic cylinder is not stressed and no damping force is generated inside, thus preventing damage to the floor beam. After the cab tilts past the center of gravity, it is locked by the tilting limit block in the bracket assembly and the limit block at the upper end of the hydraulic cylinder piston rod, thus limiting the movement. When the cab falls back from the position past the center of gravity, the hydraulic cylinder piston rod can pull the tilting limit block to make the cab fall back.

[0004] However, when using the above technical solutions, on the one hand, after the cab is tilted into place, it is limited by the piston rod engaging with the tilt limit block to prevent the cab from falling after tilting. During the limiting process, the lifting hydraulic cylinder is still under force. Once the lifting hydraulic cylinder fails, there is a risk that the cab will tilt and fall (the cab will tilt forward under its own weight). On the other hand, during the lifting process of the cab, if the lifting hydraulic cylinder fails, especially when the cab tilt angle is large, the cab will accelerate back down (the cab will rotate downward under its own weight), causing damage. It can be seen that the above technical solutions still cannot solve the safety problem during the cab lifting process. Summary of the Invention

[0005] In order to solve the technical problems of the cab's risk of falling back and tipping over in the prior art, the present invention provides a cab lifting device, a commercial vehicle and a cab lifting method thereof, which can improve the safety of cab tipping over and avoid the cab falling and falling back when the lifting cylinder fails.

[0006] In a first aspect, the present invention provides a cab lifting device to solve the above-mentioned technical problems, including a lifting cylinder, the cylinder body of which is rotatably mounted on the vehicle frame, the piston rod of which is connected to the cab crossbeam, and a limiting plate, the upper end of which is hinged to the piston rod of which is located on one side of which is located. The limiting plate is provided with a communicating guide groove and a limiting groove, the limiting groove being located below the guide groove. A limiting shaft is provided at the upper end of the cylinder body of which the lifting cylinder is located. When the cab is flipped and returned to its original position, the guide groove and the limiting groove can slide relative to the limiting shaft. When the cab falls back during the lifting process, the limiting shaft can abut against the upper end of the limiting groove to prevent the cab from falling back. When the cab is lifted to its final position, the limiting shaft can abut against the lower end of the limiting groove to prevent the cab from falling.

[0007] This invention provides a limiting plate that is hinged to the piston rod of the lifting cylinder, and designs a connecting guide groove and a limiting groove on the limiting plate. In conjunction with the limiting shaft at the upper end of the cylinder, it provides a limiting function to prevent the cab from falling back during the lifting process and falling after being flipped into place when the lifting cylinder fails. This makes the limiting of the cab independent of the lifting cylinder, improving the reliability of the limiting and thus improving the safety of the cab flipping.

[0008] Furthermore, a transition groove is inclined between the guide groove and the limiting groove, and the transition groove is inclined towards the upper end of the limiting groove.

[0009] The present invention can ensure that the limiting shaft can smoothly enter the limiting groove by setting the transition groove, which greatly avoids movement jamming between the limiting plate and the limiting shaft.

[0010] Furthermore, the upper end of the limiting groove has an arc-shaped structure, and the top position of the upper end of the limiting groove is higher than the lower end position of the guide groove.

[0011] This invention sets the top of the limiting groove higher than the bottom of the guide groove, so that after the limiting is stopped, the limiting plate can engage with the limiting shaft, preventing the limiting shaft from slipping out of the limiting groove and entering the guide groove under external force, thus preventing the cab from falling back and causing damage.

[0012] Furthermore, a gate is rotatably mounted on the limiting plate at the upper end of the limiting groove, and a return spring is provided between the gate and the limiting plate. A limiting post is also provided on one side of the limiting plate at the upper end of the limiting groove. The return spring can drive the gate to return to a position below the limiting post and not abutting against the limiting post. The gate can rotate under the pushing action of the limiting shaft. When the limiting post abuts against the gate, the limiting shaft cannot enter the upper end of the limiting groove.

[0013] This invention effectively prevents the limiting shaft from entering the upper end of the limiting groove and causing movement jamming during the normal return of the cab by setting a gate, thus ensuring the normal return of the cab.

[0014] Furthermore, it also includes two floating plates. The lower end of the floating plates is hinged to the piston rod of the lifting cylinder, and the upper ends of the two floating plates are slidably connected to the connecting seats. The connecting seats are connected to the cab crossbeam. The connecting seats are provided with two sliding grooves along the length of the frame. The two sliding grooves are symmetrically arranged, and the pins at the upper end of the floating plates can slide along the corresponding sliding grooves.

[0015] This invention, by setting a floating pull plate, can prevent the cab from moving up and down under bumpy road conditions, thus eliminating the need for the lifting cylinder to reciprocate and extend, and avoiding the force exerted on the rigid connection between the lifting cylinder and the cab, which could cause damage to the cab or the lifting cylinder.

[0016] Furthermore, it also includes an installation component, which is connected to the vehicle frame and the lifting cylinder. The limiting plate is located outside the installation component, and the installation component is located directly below the connecting seat. The vertical center plane of the installation component is coplanar with the vertical center plane of the connecting seat. The limiting groove and the guide groove are both vertically arranged.

[0017] By ensuring that the vertical center plane of the mounting component is coplanar with the vertical center plane of the connecting seat, the present invention can guarantee that the lifting cylinder rotates at a small angle when the cab is lifted, thereby increasing the vertical force of the lifting cylinder. Compared with the inclined setting, this invention can reduce the number of lifting cylinders.

[0018] Furthermore, the mounting assembly includes a mounting base and a fixing base. The mounting base is connected to the vehicle frame. The mounting base has a Z-shaped structure, and the fixing base has a gate-shaped structure. The upper end of the lifting cylinder is rotatably disposed between the mounting base and the fixing base. The mounting base is located directly below the connecting base. The vertical center plane of the mounting base is coplanar with the vertical center plane of the connecting base. Pin holes are provided at the middle positions of the fixing base and the mounting base. The two ends of the limiting shaft extend from the corresponding pin holes, and the limiting plate is located on the outside of the fixing base.

[0019] The present invention enables reliable support and installation of the lifting cylinder through the mounting base and the fixing base.

[0020] Furthermore, a counterweight is provided on the limiting plate on one side of the limiting groove and at the lower part of the guide groove.

[0021] The present invention can drive the limiting plate to rotate by setting a counterweight, so that the limiting plate drives itself to rotate under its own weight, thereby making the limiting shaft enter the limiting groove more smoothly and further increasing the smoothness of the movement of the limiting shaft between the guide groove and the limiting groove.

[0022] Secondly, the present invention also provides a commercial vehicle, including a frame and a cab, the cab being rotatably mounted on the frame, and further including the aforementioned cab lifting device, the mounting seat being connected to the frame, and the connecting seat being connected to the crossbeam of the cab.

[0023] Thirdly, the present invention also provides a method for lifting the cab of a commercial vehicle, for use in the aforementioned commercial vehicle, comprising the following steps:

[0024] When the cab is subjected to bumps and moves up and down, the floating plate rotates and its upper end moves laterally along the slide groove. There is no force between the lifting cylinder and the crossbeam of the cab.

[0025] When the cab is lifted, the piston rod drives the limiting plate to move upward, and the guide groove and the limiting groove move relative to the limiting shaft;

[0026] When the lifting cylinder suddenly fails during the lifting process of the cab, and the limiting shaft is located in the limiting groove, the limiting plate moves downward, the limiting shaft abuts against the upper end of the limiting groove, and the cab no longer falls back down;

[0027] Once the cab is raised to its position, the limiting shaft abuts against the lower end of the limiting groove, preventing the cab from continuing to tilt and fall.

[0028] When the cab returns to its original position, the piston rod drives the limiting plate to move downward, and the limiting groove and the guide groove move relative to the limiting shaft.

[0029] As can be seen from the above technical solutions, the present invention has the following advantages:

[0030] This invention provides a cab lifting device, a commercial vehicle, and a cab lifting method thereof. By setting a limiting plate hinged to the piston rod of the lifting cylinder, and designing a connecting guide groove and a limiting groove on the limiting plate, in conjunction with a limiting shaft at the upper end of the cylinder, it provides a limiting effect on the cab's fall during lifting and after tilting to the correct position, even in the event of lifting cylinder failure. This makes cab limiting independent of the lifting cylinder, improving limiting reliability and thus enhancing cab tilting safety. The transition groove ensures smooth entry of the limiting shaft into the limiting groove, greatly avoiding movement jamming between the limiting plate and the limiting shaft. By setting the top of the limiting groove higher than the lower end of the guide groove, the limiting plate engages with the limiting shaft after limiting, preventing the limiting shaft from slipping into the guide groove under external force, thus preventing further damage from the cab's continued fall. The gate effectively prevents the limiting shaft from entering the upper end of the limiting groove during the normal return of the cab. The limiting mechanism causes movement stagnation, ensuring normal cab descent. The floating pull plate prevents the cab from moving up and down on bumpy roads, eliminating the need for the lifting cylinder to reciprocate and extend, thus avoiding the rigid connection between the lifting cylinder and the cab and preventing damage to either the cab or the lifting cylinder. The coplanarity of the vertical center plane of the mounting component with the vertical center plane of the connecting seat ensures that the lifting cylinder rotates at a small angle during cab lifting, increasing the vertical force of the lifting cylinder and reducing the number of lifting cylinders compared to an inclined setup. The mounting and fixing seats reliably support the lifting cylinder and prevent cylinder tilting, ensuring the piston rod extends vertically. The counterweight drives the limiting plate to rotate under its own weight, allowing the limiting shaft to enter the limiting groove more smoothly, further increasing the smoothness of the limiting shaft's movement between the guide groove and the limiting groove. Attached Figure Description

[0031] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0033] Figure 2 This is a schematic diagram of the lifting cylinder in Embodiment 1 of the present invention.

[0034] Figure 3 This is a schematic diagram of the installation component in Embodiment 1 of the present invention.

[0035] Figure 4This is a schematic diagram of the limiting plate in Embodiment 1 of the present invention.

[0036] Figure 5 This is a diagram showing the state of the cab moving downwards in Embodiment 1 of the present invention.

[0037] Figure 6 This is a diagram showing the state of the cab moving upwards in Embodiment 1 of the present invention.

[0038] Figure 7 The lifting state is as described in Embodiment 1 of the present invention. Figure 1 .

[0039] Figure 8 This is a state diagram of the limit position during the lifting process in Embodiment 1 of the present invention.

[0040] Figure 9 The lifting state is as described in Embodiment 1 of the present invention. Figure 2 .

[0041] Figure 10 This is a state diagram of the flip limit switch according to Embodiment 1 of the present invention.

[0042] Figure 11 This is a state diagram of the return position in Embodiment 1 of the present invention.

[0043] Figure 12 This is a schematic diagram of the assembly structure of the mounting components and the lifting cylinder in Embodiment 1 of the present invention.

[0044] In the diagram, 1. Lifting cylinder; 1-1. Cylinder body; 1-2. Limiting shaft; 1-3. Piston rod; 2. Limiting plate; 2-1. Guide groove; 2-2. Limiting groove; 2-3. Transition groove; 2-4. Counterweight; 3. Brake; 4. Limiting post; 5. Frame; 6. Floating pull plate; 7. Connecting seat; 8. Crossbeam; 9. Pin shaft; 10. Mounting assembly; 10-1. Mounting seat; 10-2. Fixing seat; 10-3. Pin hole; 11. Slide groove. Detailed Implementation

[0045] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0046] Example 1

[0047] like Figure 1 and Figure 4As shown, this specific embodiment provides a cab lifting device, including a lifting cylinder 1. The cylinder body 1-1 of the lifting cylinder 1 is rotatably mounted on the vehicle frame 5. The piston rod 1-3 of the lifting cylinder 1 is connected to the cab crossbeam 8. It also includes a limiting plate 2. The upper end of the limiting plate 2 is hinged to the piston rod 1-3 of the lifting cylinder 1. The limiting plate 2 is located on one side of the lifting cylinder 1. The extension and retraction of the piston rod 1-3 can drive the limiting plate 2 to move up and down. The limiting plate 2 is provided with a communicating guide groove 2-1 and a limiting groove 2-2. The limiting groove 2-2 is located within the guide groove 2-1. Below the side of 1, the upper end of the cylinder body 1-1 of the lifting cylinder 1 is provided with a limiting shaft 1-2. The limiting shaft 1-2 extends into the guide groove 2-1 or the limiting groove 2-2 of the limiting plate 2. When the cab is flipped and returned to its original position, the guide groove 2-1 and the limiting groove 2-2 can slide relative to the limiting shaft 1-2. When the cab falls back during the lifting process, the limiting shaft 1-2 can abut against the upper end of the limiting groove 2-2 to prevent the cab from falling back. When the cab is lifted into place, the limiting shaft 1-2 can abut against the lower end of the limiting groove 2-2 to prevent the cab from falling.

[0048] This embodiment sets up a limiting plate 2 that is hinged to the piston rod 1-3 of the lifting cylinder 1, and designs a guide groove 2-1 and a limiting groove 2-2 that are connected on the limiting plate 2. Together with the limiting shaft 1-2 at the upper end of the cylinder body 1-1, it provides a limiting effect on the cab's fall during the lifting process and the fall after it is flipped into place when the lifting cylinder 1 fails. This makes the limiting of the cab independent of the lifting cylinder 1, improves the reliability of the limiting, and thus improves the safety of the cab flipping.

[0049] To ensure that the limiting shaft 1-2 can smoothly move in and out between the guide groove 2-1 and the limiting groove 2-2 during the movement of the limiting plate 2, such as Figure 4 As shown, in this embodiment, a transition groove 2-3 is inclined between the guide groove 2-1 and the limiting groove 2-2, and the transition groove 2-3 is inclined towards the upper end of the limiting groove 2-2. Furthermore, in order to prevent the limiting shaft 1-2 from sliding off under external force after it abuts against the upper end of the limiting groove 2-2, the upper end of the limiting groove 2-2 has an arc-shaped structure, and the top position of the upper end of the limiting groove 2-2 is higher than the lower end position of the guide groove 2-1. With this setting, after the limiting is achieved, the limiting plate 2 can engage with the limiting shaft 1-2, preventing the limiting shaft 1-2 from sliding off the limiting groove 2-2 and entering the guide groove 2-1 under external force, which would cause the cab to continue to fall and cause damage.

[0050] Because the limiting plate 2 moves in both vertical and horizontal directions during the cab's tilting and lowering process, to prevent the limiting shaft 1-2 from getting stuck in the upper end of the limiting groove 2-2 during normal cab tilting, thus affecting the normal raising of the limiting plate 2, as follows: Figure 4 and Figure 9As shown, in this embodiment, a gate 3 is rotatably mounted on the limiting plate 2 at the upper end of the limiting groove 2-2. A return spring is provided between the gate 3 and the limiting plate 2. A limiting post 4 is also provided on one side of the limiting plate 2 at the upper end of the limiting groove 2-2. The return spring can drive the gate 3 to return to a position below the limiting post 4 without abutting against the limiting post 4. The gate 3 can rotate under the pushing action of the limiting shaft 1-2. When the limiting post 4 abuts against the gate 3, the limiting shaft 1-2 cannot enter the upper end of the limiting groove 2-2. Specifically, a mounting shaft is provided on the limiting plate 2, and the gate 3 is rotatably mounted on the mounting shaft through a bushing and a nut. A return spring is installed between the limit plate 2 and the limit plate 2. The return spring is a torsion spring, which is rotatably mounted on the mounting shaft. The two support legs of the torsion spring abut against the gate and the limit plate 2 respectively. When the limit plate 2 rises and the limit groove 2-2 rises relative to the limit shaft 1-2, the gate 3 rotates downward to one side under the pushing action of the limit shaft 1-2 and then returns to its original position. This does not obstruct the relative movement between the limit groove 2-2 and the limit shaft 1-2. When the limit groove 2-2 moves downward relative to the limit shaft 1-2, the limit shaft 1-2 pushes the gate 3 upward to abut against the limit post 4. Under the obstruction of the gate 3, the limit shaft 1-2 will not enter the top of the limit groove 2-2. With the movement of the limit plate 2, it smoothly enters the guide groove 2-1, ensuring the normal descent of the cab.

[0051] Under bumpy road conditions, the cab will move up and down. If the lifting cylinder 1 is directly hinged to the cab crossbeam 8, there will be a force between the cab and the lifting cylinder 1, causing damage to both. To avoid this problem, such as Figure 1 , Figure 5 and Figure 6 As shown, in this embodiment, two floating plates 6 are also included. The lower end of the floating plates 6 is hinged to the piston rod 1-3 of the lifting cylinder 1 by a pin. The upper ends of the two floating plates 6 are slidably connected to the connecting seat 7. The connecting seat 7 is connected to the cab crossbeam 8. Two sliding grooves 11 are provided on the connecting seat 7 along the length direction of the frame 5. The two sliding grooves 11 are symmetrically arranged. The pin 9 at the upper end of the floating plates 6 can slide along the corresponding sliding groove 11. When the cab is bumped and moves upward, the upper end of the floating plates 6 moves towards the middle along the sliding groove 11 to ensure that the piston rod and the cab crossbeam 8 are not impacted. When the cab is bumped and moves downward, the upper end of the floating plates 6 moves towards both ends along the sliding groove 11 to ensure that the piston rod and the cab crossbeam 8 are not impacted.

[0052] In the prior art, due to the space limitations between the cab and the frame 5, the lifting cylinder 1 is in an inclined state before the cab is lifted. The thrust of the lifting cylinder 1 is only the upward component used to lift the cab. When dealing with heavy cabs, at least two lifting cylinders 1 are often required to lift the cab, increasing cost and structural complexity. In this embodiment, as... Figure 1 , Figure 3 and Figure 12 As shown, it also includes an installation assembly 10, which is connected to the vehicle frame 5 and the lifting cylinder 1. The limiting plate 2 is located outside the installation assembly 10, which is located directly below the connecting seat 7. The vertical center plane of the installation assembly 10 is coplanar with the vertical center plane of the connecting seat 7. The limiting groove 2-2 and the guide groove 2-1 are both vertically arranged. By ensuring that the vertical center plane of the installation assembly 10 is coplanar with the vertical center plane of the connecting seat 7, it is possible to ensure that the lifting cylinder 1 is nearly vertical, i.e., with a small tilt angle to the vertical direction. Consequently, when the cab is lifted, the lifting cylinder 1 rotates at a small angle, increasing the vertical force of the lifting cylinder 1. Compared with the tilted arrangement in the prior art, this reduces the number of lifting cylinders 1. Furthermore, the installation assembly 10 includes a mounting seat 10-1 and a fixing seat 10-2. The mounting seat 10-1 is connected to the vehicle frame 5, and both the mounting seat 10-1 and the fixing seat 10-2 are... The structure is a bent structure. The mounting base 10-1 has a U-shaped structure, and the fixing base 10-2 has a door-shaped structure. The two ends of the mounting base 10-1 are bolted to the frame 5, and the two ends of the fixing base 10-2 are bolted to the two sides of the protruding part in the middle of the mounting base 10-1. The upper end of the cylinder body 1-1 of the lifting cylinder 1 is rotatably disposed between the mounting base 10-1 and the fixing base 10-2. The mounting base 10-1 is located directly below the connecting base 7. The vertical center plane of the mounting base 10-1 is coplanar with the vertical center plane of the connecting base 7. The fixing base 10-2 and the mounting base 10-1 are provided with pin holes 10-3 in the middle position. The two ends of the limiting shaft 1-2 extend from the corresponding pin holes 10-3. The limiting plate 2 is located outside the fixing base 10-2. The cooperation between the fixing base 10-2 and the mounting base 10-1 can reliably support the lifting cylinder 1 and further ensure a large vertical force component.

[0053] Because the lifting cylinder 1 is vertically positioned, the piston rod 1-3 extends and retracts vertically, thereby driving the limiting plate 2 to rise and fall vertically. However, during vertical rise and fall, when the limiting shaft 1-2 moves in and out between the guide groove 2-1 and the limiting groove 2-2, the limiting shaft 1-2 first has a collision effect on the limiting plate 2. Then, the limiting plate 2 swings under the action of the limiting shaft 1-2 before entering the limiting groove 2-2. There is a large force between the limiting shaft 1-2 and the limiting plate 2, which adversely affects the service life of both. To solve this problem, such as Figure 4As shown, a counterweight 2-4 is provided on the limiting plate 2 on one side of the limiting groove 2-2 and at the lower part of the guide groove 2-1. With this arrangement, the counterweight 2-4 can drive the limiting plate 2 to swing actively. When it reaches the transition part, the limiting shaft 1-2 can smoothly generate relative movement and enter the limiting groove 2-2.

[0054] Example 2

[0055] This embodiment provides a commercial vehicle, including a frame 5 and a cab. The cab is rotatably mounted on the frame 5 via a rotating support assembly. It also includes the cab lifting device from Embodiment 1. The mounting seat 10-1 is connected to the frame 5, and the connecting seat 7 is connected to the crossbeam 8 of the cab.

[0056] Example 3

[0057] like Figures 5 to 12 As shown, this embodiment provides a method for lifting the cab of a commercial vehicle, used in the commercial vehicle of Embodiment 2, including the following steps:

[0058] When the cab is subjected to bumps and moves up and down, the floating pull plate 6 rotates and its upper end moves laterally along the slide 11, and there is no force between the lifting cylinder 1 and the crossbeam 8 of the cab.

[0059] When the cab is lifted, the piston rod 1-3 drives the limiting plate 2 to move upward. The guide groove 2-1 and the limiting groove 2-2 move relative to the limiting shaft 1-2. First, the guide groove 2-1 moves relative to the limiting shaft 1-2. Then, through the transition part, the limiting groove 2-2 moves relative to the limiting shaft 1-2. When the upper end of the limiting groove 2-2 begins to enter through the limiting shaft 1-2, the gate 3 is pushed downward by the limiting shaft 1-2 until the limiting groove 2-2 moves upward continuously. The limiting shaft 1-2 no longer contacts the gate 3, and the gate 3 resets.

[0060] When the lifting cylinder 1 suddenly fails during the lifting process of the cab, and the limiting shaft 1-2 is located in the limiting groove 2-2, the limiting plate 2 moves downward, and the limiting shaft 1-2 abuts against the upper end of the limiting groove 2-2, and the cab no longer falls back. When the lifting cylinder 1 suddenly fails while the limiting shaft 1-2 is located in the guide groove 2-1, the cab has already returned to its original position and is relatively close to the frame 5. Compared with the sudden failure when the limiting shaft 1-2 is located in the limiting groove 2-2, the damage to the cab is smaller or even non-existent. Therefore, there is no need to add a limiting device in the guide groove 2-1 to prevent it from falling back.

[0061] Once the cab is raised to its position, the limiting shaft 1-2 abuts against the lower end of the limiting groove 2-2, preventing the cab from continuing to tilt and fall.

[0062] When the cab returns to its original position, the piston rod 1-3 drives the limiting plate 2 to move downward. The limiting groove 2-2 and the guide groove 2-1 move relative to the limiting shaft 1-2. First, the limiting groove 2-2 moves relative to the limiting shaft 1-2, and then, through the transition section, the guide groove 2-1 moves relative to the limiting shaft 1-2. When the upper end of the limiting groove 2-2 begins to leave the limiting shaft 1-2, the gate 3 is pushed upward by the limiting shaft 1-2 until the gate 3 abuts against the limiting post 4. The limiting plate 2 continues to move downward, and the limiting shaft 1-2 enters the guide groove 2-1 through the transition section.

[0063] This embodiment achieves a closed-loop safety system for the entire cab lifting process by precisely timing the buffering function of the floating pull plate 6 and the mechanical protection function of the limiting plate 2. Under bumpy conditions, the floating pull plate 6 completely removes the interaction force between the lifting cylinder 1 and the cab through rotation and lateral sliding, effectively protecting the hydraulic system. During the lifting process, the limiting plate 2 moves synchronously with the piston rod 1-3, and its guide groove 2-1 forms a dynamic fit with the limiting shaft 1-2. In particular, when the lifting cylinder 1 suddenly fails, the limiting plate 2 moves downward, causing the limiting shaft 1-2 to momentarily abut against the upper end of the limiting groove 2-2 to form a mechanical brake, completely eliminating the risk of the cab accelerating back down. After the cab is lifted to the correct position, the limiting shaft 1-2 and the lower end of the limiting groove 2-2 form a hard limit to prevent overturning accidents. Through pure mechanical linkage, the entire process of passive safety control is achieved without the need for external energy or control units, significantly improving the operational safety and system reliability of commercial vehicles.

[0064] As can be seen from the above specific embodiments, the present invention has the following beneficial effects:

[0065] 1. By setting a limiting plate 2 that is hinged to the piston rod 1-3 of the lifting cylinder 1, and designing a connecting guide groove 2-1 and a limiting groove 2-2 on the limiting plate 2, in conjunction with the limiting shaft 1-2 at the upper end of the cylinder body 1-1, a limiting function is provided to prevent the cab from falling back during the lifting process and falling after being tilted into place when the lifting cylinder 1 fails. This makes the limiting of the cab independent of the lifting cylinder 1, improving the reliability of the limiting and thus improving the safety of the cab tilting. The transition groove 2-3 ensures that the limiting shaft 1-2 can smoothly enter the limiting groove 2-2, greatly avoiding movement jamming between the limiting plate 2 and the limiting shaft 1-2.

[0066] 2. By setting the top of the limiting groove 2-2 higher than the bottom of the guide groove 2-1, the limiting plate 2 can engage with the limiting shaft 1-2 after the limiting is completed, preventing the limiting shaft 1-2 from slipping off from the limiting groove 2-2 and entering the guide groove 2-1 under external force, thus preventing the cab from falling back and causing damage.

[0067] 3. By setting the gate 3, the limit shaft 1-2 is effectively prevented from entering the upper end of the limit groove 2-2 and causing movement jamming during the normal return of the cab, thus ensuring the normal return of the cab.

[0068] 4. By setting up the floating pull plate 6, it can be prevented from moving up and down with the cab under bumpy road conditions, without the need for the lifting cylinder 1 to reciprocate and extend, thus avoiding the force between the rigid connection between the lifting cylinder 1 and the cab, which could cause damage to the cab or the lifting cylinder 1.

[0069] 5. By having the vertical center plane of the mounting component 10 coplanar with the vertical center plane of the connecting seat 7, it can be ensured that the lifting cylinder 1 rotates at a small angle when the cab is lifted, thereby increasing the vertical force of the lifting cylinder 1. Compared with the inclined setting, the number of lifting cylinders 1 can be reduced.

[0070] 6. The mounting base 10-1 and the fixed base 10-2 provide reliable support for the lifting cylinder 1 and prevent the cylinder body 1-1 from tilting, ensuring that the piston rod 1-3 extends vertically.

[0071] 7. By setting the counterweight 2-4, the limiting plate 2 can be driven to rotate, so that the limiting plate 2 can rotate under its own gravity, thereby making the limiting shaft 1-2 enter the limiting groove 2-2 more smoothly, and further increasing the smoothness of the movement of the limiting shaft 1-2 between the guide groove 2-1 and the limiting groove 2-2.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cab lifting device, comprising a lifting cylinder (1), characterized in that, The cylinder body (1-1) of the lifting cylinder (1) is rotatably mounted on the vehicle frame (5). The piston rod (1-3) of the lifting cylinder (1) is connected to the cab crossbeam (8). It also includes a limiting plate (2). The upper end of the limiting plate (2) is hinged to the piston rod (1-3) of the lifting cylinder (1). The limiting plate (2) is located on one side of the lifting cylinder (1). The limiting plate (2) is provided with a communicating guide groove (2-1) and a limiting groove (2-2). The limiting groove (2-2) is located below and to the side of the guide groove (2-1). The upper end of the cylinder body (1-1) of the lifting cylinder (1) is provided with a limiting shaft (1-2). When the cab is flipped and returned to its original position, the guide groove (2-1) and the limiting groove (2-2) can slide relative to the limiting shaft (1-2). When the cab falls back during the lifting process, the limiting shaft (1-2) can abut against the upper end of the limiting groove (2-2) to prevent the cab from falling back. When the cab falls after being lifted to its position, the limiting shaft (1-2) can abut against the lower end of the limiting groove (2-2) to prevent the cab from overturning.

2. The cab lifting device as described in claim 1, characterized in that, A transition groove (2-3) is inclined between the guide groove (2-1) and the limiting groove (2-2), and the transition groove (2-3) is inclined towards the upper end of the limiting groove (2-2).

3. The cab lifting device as described in claim 2, characterized in that, The upper end of the limiting groove (2-2) has an arc-shaped structure, and the top of the upper end of the limiting groove (2-2) is higher than the lower end of the guide groove (2-1).

4. The cab lifting device as described in claim 3, characterized in that, A gate (3) is rotatably mounted on the limiting plate (2) at the upper end of the limiting groove (2-2). A reset spring is provided between the gate (3) and the limiting plate (2). A limiting post (4) is also provided on one side of the limiting plate (2) at the upper end of the limiting groove (2-2). The reset spring can drive the gate (3) to reset to the position below the limiting post (4) and not to abut against the limiting post (4). The gate (3) can rotate under the pushing action of the limiting shaft (1-2). When the limiting post (4) abuts against the gate (3), the limiting shaft (1-2) cannot enter the upper end of the limiting groove (2-2).

5. The cab lifting device as described in claim 4, characterized in that, It also includes two floating plates (6), the lower end of which is hinged to the piston rod (1-3) of the lifting cylinder (1), the upper ends of the two floating plates (6) are slidably connected to the connecting seat (7), the connecting seat (7) is connected to the cab crossbeam (8), and the connecting seat (7) is provided with two sliding grooves (11) along the length direction of the frame (5). The two sliding grooves (11) are symmetrically arranged, and the pin (9) at the upper end of the floating plate (6) can slide along the corresponding sliding groove (11).

6. The cab lifting device as described in claim 5, characterized in that, It also includes an installation component (10), which is connected to the frame (5) and the lifting cylinder (1). The limiting plate (2) is located outside the installation component (10). The installation component (10) is located directly below the connecting seat (7). The vertical center plane of the installation component (10) is coplanar with the vertical center plane of the connecting seat (7). The limiting groove (2-2) and the guide groove (2-1) are both vertically arranged.

7. The cab lifting device as described in claim 6, characterized in that, The mounting assembly (10) includes a mounting base (10-1) and a fixing base (10-2). The mounting base (10-1) is connected to the frame (5). The mounting base (10-1) has a U-shaped structure, and the fixing base (10-2) has a door-shaped structure. The upper end of the cylinder body (1-1) of the lifting cylinder (1) is rotatably disposed between the mounting base (10-1) and the fixing base (10-2). The mounting base (10-1) is located directly below the connecting seat (7). The vertical center plane of the mounting base (10-1) is coplanar with the vertical center plane of the connecting seat (7). The fixing base (10-2) and the mounting base (10-1) are provided with pin holes (10-3) at the middle position. The two ends of the limiting shaft (1-2) extend from the corresponding pin holes (10-3) respectively. The limiting plate (2) is located outside the fixing base (10-2).

8. The cab lifting device as described in claim 7, characterized in that, The limiting plate (2) is provided with a counterweight (2-4) located on one side of the limiting groove (2-2) and below the guide groove (2-1).

9. A commercial vehicle, comprising a frame (5) and a cab, the cab being rotatably mounted on the frame (5), characterized in that, It also includes the cab lifting device as described in claim 8, wherein the mounting base (10-1) is connected to the frame (5) and the connecting base (7) is connected to the crossbeam (8) of the cab.

10. A method for lifting the cab of a commercial vehicle, characterized in that, For use in the commercial vehicle as described in claim 9, the method includes the following steps: When the cab is subjected to bumps and moves up and down, the floating pull plate (6) rotates and its upper end moves laterally along the slide groove (11), and there is no force between the lifting cylinder (1) and the crossbeam (8) of the cab; When the cab is lifted, the piston rod (1-3) drives the limiting plate (2) to move upward, and the guide groove (2-1) and the limiting groove (2-2) move relative to the limiting shaft (1-2); When the lifting cylinder (1) suddenly fails during the lifting process of the cab, and the limiting shaft (1-2) is located in the limiting groove (2-2), the limiting plate (2) moves downward, the limiting shaft (1-2) abuts against the upper end of the limiting groove (2-2), and the cab no longer falls back down; Once the cab is raised to its position, the limiting shaft (1-2) abuts against the lower end of the limiting groove (2-2), preventing the cab from continuing to roll and fall. When the cab returns to its original position, the piston rod (1-3) drives the limiting plate (2) to move downward, and the limiting groove (2-2) and the guide groove (2-1) move relative to the limiting shaft (1-2).

Images