CN110770053B

CN110770053B - Vehicle and lifting device thereof

Info

Publication number: CN110770053B
Application number: CN201880032198.8A
Authority: CN
Inventors: 包玉奇; 任冠男; 刘玉洪
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2018-12-21
Filing date: 2018-12-21
Publication date: 2021-10-15
Anticipated expiration: 2038-12-21
Also published as: CN110770053A; WO2020124592A1

Abstract

A lifting device (200) and a vehicle (10) having the same. A lifting device (200) for connecting a suspension mechanism (300) of a vehicle (10) to a chassis (100), comprising: a multi-link mechanism and a deformation driving mechanism. The first end of the multi-link mechanism is hinged with the chassis (100), and the second end of the multi-link mechanism is hinged with the suspension mechanism (300). The deformation driving mechanism is in transmission connection with the multi-link mechanism and is used for driving the multi-link mechanism to drive the chassis (100) to move up and down. The chassis (100) can be lifted by the lifting device (200) to adjust the gravity center of the vehicle (10), so that the vehicle (10) can change the height of the chassis according to actual needs under high-speed motion, low-speed motion, climbing or other scenes.

Description

Vehicle and lifting device thereof

Technical Field

The invention relates to a vehicle and a lifting device thereof, belonging to the technical field of image shooting auxiliary equipment.

Background

In the film industry or shooting by a photo enthusiast, a pan-tilt vehicle provided with a pan-tilt and a camera is used for remote shooting and first-view-angle driving so as to shoot a picture with a special view angle. The existing cloud platform truck generally connects the chassis and the wheel shaft of the wheel pair together in a rotating manner, so that the chassis can be driven to lift through the rotation of the driving wheel group to adjust the integral gravity center of the cloud platform truck, and the possibility of tipping the cloud platform truck is reduced. However, as the pan tilt and the camera mounted on the chassis have heavy weight, the way of driving the chassis to move up and down by rotation cannot realize self-locking, and sometimes unbalanced stress occurs.

Disclosure of Invention

In order to solve the above and other potential problems in the prior art, embodiments of the present invention provide a vehicle and a lifting device thereof.

According to some embodiments of the present invention there is provided a lifting device for connecting a suspension mechanism and a chassis of a vehicle, comprising: a multi-link mechanism and a deformation driving mechanism; the first end of the multi-link mechanism is hinged with the chassis, and the second end of the multi-link mechanism is hinged with the suspension mechanism; the deformation driving mechanism is in transmission connection with the multi-link mechanism and is used for driving the multi-link mechanism to drive the chassis to move up and down.

According to some embodiments of the invention, there is provided a vehicle comprising: the device comprises a chassis, a plurality of suspension mechanisms, a plurality of wheel sets and a lifting device; the wheel sets are respectively arranged on two opposite sides of the chassis; the wheel set includes: the wheel shaft and the wheels are sleeved on the wheel shaft, each wheel shaft is rotatably connected with the corresponding suspension mechanism, and the suspension mechanisms are connected with the chassis through the lifting device; the lifting device comprises: a multi-link mechanism and a deformation driving mechanism; the first end of the multi-link mechanism is hinged with the chassis, and the second end of the multi-link mechanism is hinged with the suspension mechanism; the deformation driving mechanism is in transmission connection with the multi-link mechanism and is used for driving the multi-link mechanism to drive the chassis to move up and down.

According to the technical scheme of the embodiment of the invention, the lifting device for connecting the suspension mechanism and the chassis is arranged, and the lifting device can lift the chassis, so that the gravity center of the vehicle is adjusted, and the vehicle can change the height of the chassis according to needs in high-speed motion, low-speed motion, climbing or other scenes according to actual needs. Moreover, the lifting device adopts the multi-link mechanism driven by the deformation driving mechanism, so that the multi-link mechanism can be self-locked in the whole motion process through reasonable design of the multi-link mechanism, and the safety of the vehicle in the deformation process is improved.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and other objects, features and advantages of the embodiments of the present invention will become more readily understood by the following detailed description with reference to the accompanying drawings. Embodiments of the invention will now be described, by way of example and not limitation, in the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a first variation of a vehicle according to an embodiment of the present invention;

FIG. 2 is a top view of FIG. 1;

fig. 3 is a schematic structural diagram of a wheel set and a lifting device when the lifting device is located at a first position according to an embodiment of the present invention;

FIG. 4 is a top view of FIG. 3;

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4;

fig. 6 is a schematic structural diagram of the wheel set and the lifting device when the lifting device is located at the second position according to the embodiment of the present invention;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is a cross-sectional view taken along line B-B of FIG. 7;

fig. 9 is a schematic view of a second modification of the vehicle according to the embodiment of the invention;

FIG. 10 is a top view of FIG. 9;

FIG. 11 is an elevation view of a suspension mechanism and wheel set provided by an embodiment of the present invention;

fig. 12a to 12b are exploded views of fig. 11 from different perspectives;

FIG. 13 is a partial exploded view of the suspension mechanism as it is rotated to another position;

fig. 14a to 14c are schematic views illustrating a state that the suspension mechanism provided by the embodiment of the invention is rotated to different positions.

Wherein:

10-a vehicle; 20-a holder; 30-a camera; 100-a chassis; 110-an upper mounting plate; 120-lower mounting plate; 200-a lifting device; 210-a push rod; 220-a rocker arm; 230-a lifting arm; 240-chassis lifting driving motor; 250-a lead screw; 251-a screw; 252-a nut; 261-upper support arm; 262-a lower support arm; 270-a suspension; 271-first connecting arm; 272-suspension upper arm; 273-second connecting arm; 274-a lower suspension arm; 275-a base plate; 276-a support frame; 277-an articulated arm; 300-a suspension mechanism; 311-longitudinal beams; 312-a beam; 330-first part; 331-a first ratchet surface; 332-first shaft hole; 340-a second portion; 341-second ratchet surface; 342-a second shaft bore; 350-a rotating shaft; 400-wheel set; 401-vehicle wheels; 500-a vibration damping mechanism; 610-wheel angle adjustment motor.

Detailed Description

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Fig. 1 is a schematic diagram of a first modification of the vehicle 10 according to the present embodiment, and fig. 2 is a plan view of fig. 1. As shown in fig. 1 and 2, the present embodiment provides a vehicle 10 including: the chassis 100, a plurality of suspension mechanisms 300, a plurality of wheel sets 400 disposed under the chassis 100, and the lifting device 200. Wherein a plurality of wheel sets 400 are respectively disposed at two opposite sides of the chassis 100, for example, fig. 1 and 2 illustrate a scheme in which four wheel sets 400 are respectively disposed at the left and right sides of the chassis 100. Of course, in other examples, there may be more or fewer wheel sets 400, such as two wheel sets 400, three wheel sets 400, or six wheel sets 400. It will be readily appreciated that when the vehicle 10 is provided with an odd number of wheel sets 400, the even number of wheel sets 400 may be divided on opposite sides of the chassis 100, with the other wheel set 400 being provided on one of the other sides. For example, when three wheel sets 400 are provided, the wheel sets 400 may be laid out in a regular triangle or an isosceles triangle manner.

Each wheel set 400 includes: an axle (not shown) and wheels 401 sleeved on the axle are rotated by the wheels 401 to drive the vehicle 10 to move forward, backward or turn. In this embodiment, the wheel axle is rotatably connected to its corresponding suspension mechanism 300, and the suspension mechanism 300 is connected to the chassis 100 via the lifting device 200. Meanwhile, in the embodiment, the chassis 100 can be lifted by the lifting device 200, that is, the lifting device 200 can adjust the height of the chassis 100 relative to the ground so as to adjust the center of gravity of the vehicle 10, thereby improving the stability of the vehicle 10 during operation and preventing the vehicle 10 from rolling over. It should be understood that the lifting device 200 can drive the chassis 100 to move in the vertical direction, can also drive the chassis 100 to tilt, or can also drive the chassis 100 to move along a curve, and the specific movement track can be designed according to actual needs, which is not limited in this embodiment.

In this embodiment, the chassis 100 may be a plate, block, or frame-like structure having a rectangular, circular, or any other suitable shape. For example, in some examples, stamped steel plates may be used as the chassis 100; in other examples, a chassis 100 molded in block form using plastic may also be used in order to make the vehicle 10 lighter. Of course, in other examples, a combination of metal and plastic may be used to balance weight and structural strength. In other examples, as shown in fig. 1, the chassis 100 may include an upper mounting plate 110 and a lower mounting plate 120 that are oppositely disposed, and a receiving cavity is formed between the upper mounting plate 110 and the lower mounting plate 120 to receive a portion of the lifting device 200.

Alternatively, various peripheral devices may be mounted on the chassis 100 in order to extend the functionality of the vehicle 10. For example, when it is desired to take a picture using the vehicle 10, an image pickup device, such as a camera 30 or a video camera, may be mounted on the chassis 100. In some examples, the pan/tilt head 20 (including but not limited to a single-axis pan/tilt head, a two-axis pan/tilt head, and a three-axis pan/tilt head) may be mounted on the chassis 100, and then the camera 30 or an image capturing device such as a video camera may be mounted on the pan/tilt head 20, so as to enhance the stability during shooting, avoid shaking or distortion of the shot picture, and the like. As another example, when it is desired to play a competitive game using the vehicle 10, a marble firing device capable of firing bullets (such as PP bullets) may be mounted on the chassis 100. In some examples, the marble firing device may also be mounted on the holder 20 described above in order to improve the stability of the marble firing device and thus improve the shooting accuracy.

As shown in fig. 1 and 2, the suspension mechanism 300 of the wheel set 400 includes two longitudinal beams 311 respectively disposed on the outer side and the inner side of the wheel 401, and a cross beam 312 located between the two longitudinal beams 311 and fixed to the two longitudinal beams 311, that is, the present embodiment provides the suspension mechanism 300 having all or a part thereof in a U-shape which is turned upside down over the wheel 401 in fig. 1 and 2. The bottom ends of the two longitudinal beams 311 may be provided with axle holes for passing through an axle, so that the wheels 401 sleeved on the axle can rotate relative to the suspension mechanism 300, so as to drive the vehicle 10 to move forward, backward, steer and the like. In some examples, wheels 401 may be configured as mecanum wheels to allow more flexible movement of vehicle 10 over the ground. It will be readily appreciated that when the suspension mechanism 300 includes the cross member 312 described above, the lifting device 200 may be hinged with the cross member 312. Of course, the suspension mechanism 300 is not limited to the above-mentioned structure, for example, in some examples, the suspension mechanism 300 may have only one longitudinal beam 311, and the lifting device 200 is hinged with the one longitudinal beam 311. For the sake of simplicity and convenience, the solution of the present embodiment will be described below by taking the U-shaped suspension mechanism 300 shown in fig. 1 and 2 as an example, but this should not be considered as a specific limitation of the solution, and a simple replacement on the basis thereof still belongs to the protection scope of the present embodiment.

In this embodiment, the lifting device 200 may be a cylinder, a linear motor, or the like. For example, when the lifting device 200 is a cylinder, a cylinder of the cylinder may be fixed to the cross beam 312 of the suspension mechanism 300, and a piston rod of the cylinder is fixed to the bottom surface of the chassis 100 to support the chassis 100. Thus, when the height of the chassis 100 needs to be adjusted, the piston is driven to move. Similarly, when the lifting device 200 is a linear motor, the stator of the linear motor may be fixed to the cross beam 312 of the suspension mechanism 300, and the output shaft of the linear motor may be fixed to the bottom surface of the chassis 100 to support the chassis 100. Of course, the lifting device 200 may also be another single component or an assembly formed by combining multiple single components, as long as it can drive the chassis 100 to move vertically, and in this embodiment, the specific structure of the lifting device 200 is not limited. However, in order to make the technical content of the present embodiment better understood by those skilled in the art, some alternative structures of the lifting device 200 will be exemplarily described below.

Fig. 3 is a schematic structural diagram of the wheel set and the lifting device 200 when the lifting device is located at the first position according to the embodiment; FIG. 4 is a top view of FIG. 3; FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4; fig. 6 is a schematic structural view of the wheel set and the lifting device when the lifting device is located at the second position according to the present embodiment; FIG. 7 is a top view of FIG. 6; fig. 8 is a sectional view taken along line B-B in fig. 7.

As shown in fig. 3-8, in some examples, the lifting device 200 includes: a multi-link mechanism and a deformation driving mechanism. Wherein a first end of the multi-link mechanism is used for hinging with the chassis 100 (please refer to fig. 1 and 2), and a second end thereof is used for hinging with the cross beam 312 of the suspension mechanism 300. Taking fig. 3 as an example, the left end of the multi-link mechanism is hinged to the cross beam 312, and the right end of the multi-link mechanism is hinged to the chassis 100. The deformation driving mechanism is in transmission connection with the multi-link mechanism, so that mutual positions among the links in the multi-link mechanism can be changed through the driving of the deformation driving mechanism, the chassis 100 hinged with the multi-link mechanism is driven to move vertically, and then the change of the gravity center of the vehicle 10 is realized. In some examples, the deformation drive mechanism may be a manual device, such as a hand wheel secured to one or more of the multi-link mechanisms. Of course, in other examples, the deformation driving mechanism may also be an electric device mounted on the suspension mechanism 300 or on the chassis 100, such as the chassis lifting driving motor 240 (see the detailed description below).

Based on the above, in the present embodiment, by providing the multi-link mechanism connecting the chassis 100 and the suspension mechanism 300, and driving the multi-link mechanism to move by the deformation driving mechanism to change the relative positions of the links of the multi-link mechanism, the height of the chassis 100 relative to the ground can be conveniently adjusted, so as to prevent the vehicle 10 from rolling over. It will be readily appreciated that when the vehicle 10 is required to run at a high speed, or the object on which the vehicle 10 rides is high, the height of the chassis 100 may be lowered by the lifting device 200 provided between the chassis 100 and the suspension mechanism 300 to improve the smoothness of the running of the vehicle 10.

Specifically, as shown in fig. 3 to 8, the multi-link mechanism includes: a push rod 210, a rocker arm 220, and a lift arm 230. The first end of the push rod 210 is hinged to the cross beam 312, the second end of the push rod 210 is hinged to the first end of the rocker arm 220, the second end of the rocker arm 220 is hinged to the first end of the lifting arm 230, and the second end of the lifting arm 230 is hinged to the chassis 100. Taking fig. 3 as an example, the bottom end of the push rod 210 is hinged to the right end of the cross beam 312, the top end of the push rod 210 is hinged to the left end of the swing arm 220, the right end of the swing arm 220 is hinged to the left end of the lifting arm 230, and the right end of the lifting arm 230 is hinged to the chassis 100. It will be readily appreciated that by configuring the lengths of the push rod 210, the swing arm 220, and the lift arm 230 to be in appropriate proportions, the trajectory of the chassis 100 with respect to the ground can be controlled, i.e., in some examples, the push rod 210, the swing arm 220, and the lift arm 230 can be designed to be of appropriate lengths to allow the chassis 100 to be raised and lowered vertically.

In some examples, a deformation drive mechanism may be provided on the chassis 100, the deformation drive mechanism including: chassis lift drive motor 240, upper support arm 261, and lead screw 250. The first end of the upper support arm 261 is hinged to the first end of the multi-link mechanism, the second end of the upper support arm 261 is fixed to the nut 252 of the screw 250, the screw 251 of the screw 250 is used for driving the nut 252 of the screw 250 to move, and the nut 252 of the screw 250 drives the upper support arm 261 to move, so that the movement of the upper support arm 261 drives the multi-link mechanism to move, and the chassis 100 is lifted. Taking fig. 3 and fig. 5 as an example, the chassis lifting driving motor 240 is fixed on the chassis 100, and the screw 251 of the screw 250 is fixed with the output shaft of the chassis lifting driving motor 240, for example, welded together; the nut 252 of the screw 250 is fixed to the bottom end of the upper support arm 261, and the top end of the upper support arm 261 is hinged to the lifting arm 230.

When the chassis lifting driving motor 240 is started to work, the output shaft of the chassis lifting driving motor 240 drives the screw 251 of the screw 250 to rotate, and the nut 252 of the screw, which is sleeved on the screw 251, moves linearly leftwards or rightwards along the axis of the screw 251, so that the upper supporting arm 261 is driven to move linearly leftwards or rightwards. Because the top end of the upper supporting arm 261 is hinged to the lifting arm 230, the lifting arm 230 is driven by the upper supporting arm 261 to rotate, and further drives the rocker arm 220 and the push rod 210 to move, and under the synthetic action of a plurality of forces, the chassis 100 moves relative to the ground, so that the purpose of changing the height of the chassis 100 relative to the ground is achieved. Reference may be made in particular to the illustrations of fig. 3 and 6, wherein fig. 3 illustrates the chassis 100 in a raised position relative to the ground and fig. 6 illustrates the chassis 100 in a lowered position relative to the ground.

It should be understood that the screw rod and the upper support arm 261 of the present embodiment are not necessarily provided with structures, as long as the configuration is proper, and in some realizations, the two structures can be completely omitted, and the chassis lifting driving motor 240 directly drives the lifting arm 230 to rotate. In the embodiment, the lead screw 250 and the upper support arm 261 are provided in consideration of the compact structure and the transmission of the chassis lifting driving motor 240, that is, the lead screw 250 and the upper support arm 261 are provided to drive the multi-link mechanism to move by using a low-power motor, and the overall size of the lifting device 200 can be reduced, that is, a link with an excessively long length is not required, so that the lifting device 200 and the vehicle 10 are compact. Similarly, the chassis lifting/lowering driving motor 240 is not necessary, and in some examples, the screw 251 of the screw 250 may be driven to rotate by a gear structure, a link structure, or any other suitable structure, so as to drive the nut 252 to move linearly. Of course, in some examples, a handle may be provided at one end of the screw 251, for example, manually, so that the screw 251 is rotated by driving the handle to rotate.

In other examples, a deformation drive mechanism may be provided on the cross beam 312 of the suspension mechanism 300, which may also include the chassis lift drive motor 240. Specifically, an output shaft of the chassis lifting driving motor 240 penetrates through a mounting hole formed in the push rod 210, and the output shaft is fixed to the push rod 210, so that the push rod 210 is driven to rotate through the output shaft, the rocker arm 220 and the lifting arm 230 are driven to move, and the chassis 100 connected with the lifting arm 230 is driven to move relative to the ground, so that the height of the chassis 100 relative to the ground is changed. Of course, in this example, the screw 250 and the upper support arm 261 may be provided as in the above example, so that the torque of the motor is transmitted to the push rod 210 through the screw 250 and the upper support arm 261, so as to drive the multi-link mechanism including the push rod 210, the rocker 220 and the lifting arm 230 to move, thereby lifting the chassis 100. For details of how to configure the chassis lifting driving motor 240, the lead screw and the upper supporting arm 261, reference may be made to the above examples and fig. 3 to 8, which are not described herein again.

Further, as shown in fig. 1 to 8, in some examples, the lifting device 200 may further include a damping mechanism 500, a first end of the damping mechanism 500 is hinged to the swing arm 220, and a second end of the damping mechanism 500 is fixed to the chassis 100. Taking fig. 3 as an example, the bottom end of the push rod 210 is hinged to the cross beam 312, and the top end of the push rod 210 is hinged to the left end of the lifting arm 230 and the left end of the damping mechanism 500, respectively; the lifting arm 230 is further in transmission connection with a deformation driving mechanism, for example, the lifting arm 230 is hinged with the top end of an upper support arm 261, the upper support arm 261 is fixed with a nut 252 of a lead screw, and as a screw 251 of the lead screw is fixed with an output shaft of the chassis lifting motor 240, the upper support arm 261 is in transmission connection with the chassis lifting driving motor 240 through the lead screw; the right end of the damping mechanism 500 is fixed to the chassis 100. In this example, damping mechanism 500 may be any suitable damping mechanism 500 including a damping spring. For convenience of description, the technical solution will be exemplarily described with a damping spring.

Further, as shown in fig. 3 to 8, in some examples, the swing arm 220 may be provided in a triangular structure, and the push rod 210, the lift arm 230, and the damping spring are respectively hinged at three vertices of the triangular structure. Taking fig. 3 as an example, the top end of the push rod 210 is hinged to the left vertex of the triangular rocker arm 220, the left end of the lift arm 230 is hinged to the lower vertex of the triangular rocker arm 220, and the left end of the damping spring is hinged to the right vertex of the triangular rocker arm 220. By arranging the swing arm 220 in a triangular structure and then respectively hinging the push rod 210, the lifting arm 230 and the damping spring at three vertices of the triangular swing arm 220, the damping spring can be always in a good working angle when the multi-link mechanism moves, that is, when the chassis 100 is lifted, so that the damping performance thereof is not substantially reduced.

Further, with continued reference to fig. 3-8, to improve the support force for the chassis 100, in some alternative examples, the multi-link mechanism further includes a suspension 270. A first end of the suspension 270 is articulated to the suspension mechanism 300, for example, by articulating the first end of the suspension 270 to the cross beam 312. The deformation driving mechanism further includes a lower support arm 262, a first end of the lower support arm 262 is hinged with a second end of the suspension 270, and a second end of the lower support arm 262 is fixed with the nut 252 of the screw 250. Taking fig. 3 as an example, the left end of the suspension 270 is hinged to the cross beam 312, the right end of the suspension 270 is hinged to the bottom end of the lower support arm 262, and the top end of the lower support arm 262 is fixed to the nut 252 of the screw 250. It should be appreciated that in some examples, the second end of the suspension 270 may also be directly or indirectly articulated with the multi-link mechanism, whereby the suspension 270, the multi-link mechanism, and a portion of the suspension mechanism form a polygonal structure to increase the support force for the chassis.

Specifically, when the chassis lifting driving motor 240 is started, the output shaft of the chassis lifting driving motor 240 drives the screw 251 of the screw 250 to rotate, and accordingly, the nut 252 sleeved on the screw 251 is driven to move linearly leftwards or rightwards. Since the nut 252 moves linearly to the left or right, the lower support arm 262 fixed to the nut 252 correspondingly moves linearly to the left or right, and the suspension 270 hinged to the lower support arm 262 is driven to rotate.

With continued reference to fig. 3-8, in some examples, suspension 270 includes: a first connecting arm 271, a suspension upper arm 272, a second connecting arm 273, and a suspension lower arm 274. The first connecting arm 271 is fixed to the suspension mechanism 300, for example, the first connecting arm 271 is fixed to the side member 311 located inside the wheel 401, or the first connecting arm 271 is fixed to the inner surface of the cross member 312. The second connecting arm 273 is fixed to the chassis 100, which may be directly or indirectly fixed. A first end of the suspension upper arm 272 is hinged to the top end of the first connecting arm 271, and a second end of the suspension upper arm 272 is hinged to the top end of the second connecting arm 273. Similarly, a first end of the suspension lower arm 274 is hinged to the bottom end of the first connecting arm 271, and a second end of the suspension lower arm 274 is hinged to the bottom end of the second connecting arm 273. Also, the first end of the lower support arm 262 is hinged to the second connecting arm 273, for example, the first end of the lower support arm 262 is hinged to the second end of the second connecting arm 273.

Specifically, taking fig. 3 as an example, the first connecting arm 271 is fixed to the inner side surface of the cross member 312, but may extend vertically to the position of the side member 311 located inside the wheel 401. The second connecting arm 273 is fixed to the chassis 100 and disposed opposite to the first connecting arm 271. The left end of the suspension upper arm 272 is hinged to the top end of the first connecting arm 271, and the right end of the suspension upper arm 272 is hinged to the top end of the second connecting arm 273. The lower suspension arm 274 is hinged at its left end to the bottom end of the first connecting arm 271, and the lower suspension arm 274 is hinged at its right end to the bottom end of the second connecting arm 273.

By providing the suspension 270 as a four-bar linkage, the supporting capability for the chassis 100 can be improved, and the stability of the suspension 270 when moving can be enhanced, thereby improving the smoothness of the chassis 100 when being lifted and lowered.

Alternatively, as shown in fig. 3 to 8, in some specific examples, the first connecting arm 271, the suspension upper arm 272, the second connecting arm 273, and the suspension lower arm 274 may be combined into a parallelogram structure. It is apparent that when suspension 270 is driven to move by the deformable drive mechanism, the angles between upper and

lower suspension arms

272 and 274 and the horizontal plane will change accordingly.

With continued reference to fig. 3-8, in some examples, the first connecting arm 271 is integrally formed as one piece with a portion of the suspension mechanism 300. Specifically, the first connecting arm 271 and the cross member 312 or the side member 311 located inside the wheel 401 may be integrally formed. With continued reference to fig. 3, it can be seen that since the first connecting arm 271 is an integrally formed one-piece with the cross member 312 of the suspension mechanism 300, the left end of the push rod 210 is not only hinged with the cross member 312 of the suspension mechanism 300, but also simultaneously hinged with the top end of the first connecting arm 271. Of course, in other examples, when the first connecting arm 271 and the cross member 312 are two parts separately provided, the left end of the push rod 210 may be hinged to both the cross member 312 and the top end of the first connecting arm 271.

Further, with continued reference to fig. 3-8, in some examples, the lift device 200 further includes: a bottom plate 275, and a support bracket 276. Wherein, the supporting frame 276 and the second connecting arm 273 are fixed on the bottom plate 275, the supporting frame 276 is located at one side of the second connecting arm 273 far away from the first connecting arm 271, and the chassis lifting driving motor 240 is installed on the supporting frame 276. The installation of the chassis lifting drive motor 240 and the fixation to the chassis 100 are facilitated by the provision of the bottom plate 275 and the support bracket 276.

Alternatively, as shown in fig. 3 to 8, the lifting device 200 further includes an articulated arm 277 fixed to the base plate 275, the articulated arm 277 is disposed between the second connecting arm 273 and the support frame 276, and a top end of the articulated arm 277 is articulated to the second end of the lifting arm 230 described above. Specifically, as shown in fig. 3, an upwardly vertical hinge arm 277 is provided above the base plate 275, and the top end of the hinge arm 277 is hinged to the right end of the extended lifting arm 230. In this example, the upper support arm 261 may also be hinged with the right end of the lifting arm 230, but in some examples, as shown in fig. 3 to 8, the first end of the upper support arm 261 may be hinged between the first end of the lifting arm 230 and the second end of the lifting arm 230, and the hinge point of the upper support arm 261 and the lifting arm 230 is close to the second end of the lifting arm 230, so as to save the driving force, so that the chassis lifting driving motor 240 with small power may be used. Specifically, taking fig. 3 as an example, the right end of the lifting arm 230 is hinged to the top end of the hinged arm 277, the upper support arm 261 is located on the left side of the hinged arm 277, the hinged point of the hinged arm 277 and the lifting arm 230 is located between the left end and the right end of the lifting arm 230, and the hinged point is closer to the right end of the lifting arm 230, so that the chassis lifting drive motor 240 can move an object with a larger weight with a smaller torque because the pivot point is closer to the original force. From the above, through the reasonable arrangement of the supporting points, the chassis lifting driving motor 240 can pry an object with larger mass only by outputting a small force, so that the stability can be further improved.

Further, as shown in fig. 3 to 8, in some examples, the second connecting arm 273, the support bracket 276, the hinge arm 277, and the base plate 275 may be formed as a single piece by integral molding to improve strength. Moreover, the second connecting arm 273, the supporting bracket 276, the hinge arm 277 and the bottom plate 275, which are integrally formed, may be entirely or partially separated from each other, and may be entirely or partially accommodated in the accommodating space formed by the upper mounting plate 110 and the lower mounting plate 120, which are oppositely arranged.

Further, as shown in fig. 1 to 8, the vehicle 10 further includes a travel drive mechanism and a steering drive mechanism. For example, the travel driving mechanism may include a travel driving motor (not shown) in transmission connection with an axle, for driving the axle to drive the wheels 401 to rotate, so as to realize forward, backward, or steering of the vehicle 10; the steering driving mechanism may include a wheel angle adjustment motor 610 drivingly connected to the suspension mechanism 300 for selectively driving the suspension mechanism 300 to rotate the wheel 401 about the gravity direction. It will be readily appreciated that the rotational axis of the travel drive mechanism passes through the central axis of the wheel 401, and the rotational axis of the steering drive mechanism is substantially perpendicular to the central axis of the wheel body 21, i.e., the rotational axis of the steering drive mechanism is substantially perpendicular to the rotational axis of the travel drive mechanism.

It should be noted that the travel drive motor, the wheel angle adjustment motor 610, and one or more of the chassis elevation drive motor 240 described above and the suspension elevation drive motor described below in this example may be brushless motors, brushed motors, or other types of motors.

Specifically, the suspension mechanism 300 including the cross beam 312 and the two opposing longitudinal beams 311 is taken as an example: a mounting seat is arranged on the cross beam 312, a wheel angle adjusting motor 610 of the steering mechanism is mounted on the mounting seat, and an output shaft of the wheel angle adjusting motor 610 vertically penetrates through a shaft hole of the motor seat to drive the cross beam 312 to rotate. Accordingly, when the wheel angle adjustment motor 610 is activated, the output shaft of the wheel angle adjustment motor 610 drives the cross beam 312 to rotate around the gravity direction, that is, the imaginary line in fig. 5, and then drives the wheel set 400 inserted into the axle holes of the two longitudinal beams 311 to rotate around the imaginary line. It will be readily appreciated that in some examples, the steering mechanism may also include other transmission mechanisms, such as a gear train drivingly connected to the wheel angle adjustment motor 610.

In addition, the push rod 210, the swing arm 220, the lifting arm 230, the upper support arm 261, the lower support arm 262, the first connection arm 271, the suspension upper arm 272, the suspension lower arm 274, the second connection arm 273, and the hinge arm 277 described above are not limited to a specific configuration, and may be, for example, a rod member or a plate-like member.

As can be seen from the above description, the first modification of the vehicle 10 provided by the present embodiment generally relies on the lifting device 200 for connecting the suspension mechanism 300 and the chassis 100, and the lifting device 200 can lift the chassis 100 to adjust the gravity center of the vehicle 10, so as to enable the vehicle 10 to change the height of the chassis 100 as required in a high-speed movement, a low-speed movement, a climbing slope or other scenes according to actual needs. Moreover, since the lifting device 200 adopts the multi-link mechanism driven by the deformation driving mechanism, the multi-link mechanism can be self-locked in the whole movement process through reasonable design of the multi-link mechanism, so that the safety of the vehicle 10 in the deformation process is improved.

Fig. 9 is a schematic view of a second modification of the vehicle according to the present embodiment, and fig. 10 is a plan view of fig. 9. Referring now to fig. 9 and 10, a further means of altering the center of gravity of vehicle 10 is provided, as will be apparent to those skilled in the art from the detailed description that follows, generally by driving suspension mechanism 300 in rotation relative to wheel 401 along an axis of rotation parallel to the central axis of wheel 401.

Fig. 11 is a front view of the suspension mechanism and the wheel set provided in the present embodiment, fig. 12a to 12b are exploded views of fig. 11 at different viewing angles, and fig. 13 is a partial exploded view when the suspension mechanism is rotated to another position.

Referring to fig. 11-13, in some examples, the suspension mechanism 300 includes a first portion 330 and a second portion 340 that are relatively rotatable, and a locking portion for locking the first portion 330 and the second portion 340; wherein, the first part 330 can be the above-mentioned mounting seat mounted on the cross beam 312, and the first part 330 is in transmission connection with the wheel angle adjusting motor 610; the second portion 340 is fixed to the chassis 100 or hinged to the lifting device 200, for example, the second portion 340 may be hinged to the multi-link mechanism, and the second portion 340 is further rotatably connected to the first portion 330 through the rotating shaft 350, so that the angle between the first portion 330 and the bottom surface, that is, the height of the chassis 100 relative to the ground, may be adjusted by rotating the first portion 330 around the rotating shaft 350, as shown in fig. 11 and 13.

Specifically, the first portion 330 is provided with a first shaft hole 332 for the shaft 350 to pass through, the second portion 340 is provided with a second shaft hole 342 for the shaft 350 to pass through, and after the shaft 350 passes through the second shaft hole 342 and the first shaft hole 332 in sequence, the first portion 330 and the second portion 340 can be connected together. In operation, the height of the chassis 100 can be adjusted by driving the first part 330 to rotate around the rotating shaft 350, and when the first part 330 rotates to a proper angle around the rotating shaft 350, the relative positions of the first part 330 and the second part 340 can be ensured not to change by locking the first part 330 and the second part 340 through the locking part.

Taking fig. 12b as an example, in some examples, the locking portion may include a first ratchet surface 331 provided at the first portion 330, and a second ratchet surface 341 provided at the second portion 340 to be engaged with the first ratchet surface 331. When first and second ratcheted

surfaces

331 and 341 are engaged, relative rotation of first and

second portions

330 and 340 does not occur. It will be readily appreciated that the locking of the positions of the first and

second portions

330, 340 is achieved by providing cooperating ratchet formations on the first and

second portions

330, 340, the length of the shaft 350 should generally be equal to or slightly greater than the sum of the depth of the first shaft bore 332 and the depth of the second shaft bore 342. It is understood that the length of the rotation shaft 350 should not exceed the sum of the depth of the first shaft hole 332, the depth of the second shaft hole 342 and the height of the ratchet teeth on the first ratchet tooth surface 331 at maximum.

Fig. 14a to 14c are schematic views illustrating states of the suspension mechanism provided in the present embodiment when the suspension mechanism is rotated to different positions. As shown in fig. 14a to 14c, when the height of the chassis 100 needs to be adjusted, the rotating shaft 350 is partially pulled out to disengage the first ratchet surface 331 and the second ratchet surface 341, then the first portion 330 can be rotated around the rotating shaft 350 to rotate the first portion 330 from the first position of fig. 14a to the third position of fig. 14c via the second position of fig. 14b, then the first ratchet surface 331 and the second ratchet surface 341 are engaged together, and finally the rotating shaft 350 is pushed inward, so that the positions of the first portion 330 and the second portion 340 can be locked. Of course, the suspension mechanism 300 may also be changed from the third position shown in fig. 14c to the first position shown in fig. 14a in accordance with the above-described operation.

Of course, in other examples, screw 251 is used as shaft 350. The locking portion includes a first internal thread provided in the first shaft hole 332, a second internal thread provided in the second shaft hole 342, and a first external thread and a second external thread provided on the screw 251 to be engaged with the first internal thread and the second internal thread, respectively. When the first part 330 and the second part 340 need to be locked, the screw 251 passes through the second shaft hole 342 and the first shaft hole 332 in sequence, and extends into the first shaft hole 332 to a proper length, so that the first external thread on the screw 251 is in threaded connection with the first internal thread in the first shaft hole 332, and meanwhile, the second external thread on the screw 251 is also in threaded connection with the second internal thread in the second shaft hole 342, so that the first part 330 and the second part 340 are fixedly connected together through the screw 251. When the height of the chassis 100 needs to be adjusted, the first part 330 can be driven to rotate relative to the screw 251 only by loosening the screw 251, so that the height of the chassis 100 connected with the second part 340 relative to the ground is changed, and the purpose of adjusting the gravity center of the vehicle 10 is achieved.

It will be readily appreciated that the second shaft aperture 342 may also be provided in some alternative ways without a second internal thread, and correspondingly, the screw 251 is also not provided with a second external thread. At this time, only when the screw 251 passes through the second shaft hole 342 and the first shaft hole 332 in sequence and is in threaded connection with the first internal thread, the head of the screw 251 can press the second part 340 against the first part 330, and the relative positions of the first part 330 and the second part 340 can be locked. When the first part 330 needs to be rotated, only the screw 251 needs to be loosened, and the operation is relatively simple and convenient.

In other examples, the shaft 350 may be closely fitted to the first shaft hole 332 and the second shaft hole 342, so that the first part 330 and the second part 340 can be fixedly connected together when the shaft 350 passes through the second shaft hole 342 and the first shaft hole 332 in sequence. Similarly, when the head of the shaft 350 has a rib extending in the radial direction, and the rib can press the second part 340 against the first part 330 after the shaft 350 passes through the second shaft hole 342 and the first shaft hole 332 in sequence, the shaft 350 may not be arranged in a tight fit with the second shaft hole 342.

Although fig. 11-14 illustrate the position of the suspension mechanism 300 being changed manually, it should be understood that it may be accomplished in an automated manner. For example, in some examples, the axle of the wheel set 400 may be a hollow shaft (i.e., the axle is hollow), and a mounting beam for suspending the lift driving motor is inserted into the hollow shaft, and the mounting beam is fixed to the at least one longitudinal beam 311. A suspension hoist drive motor (i.e. the second part of the suspension mechanism) is mounted on the mounting beam, which is accommodated in the hollow shaft and the output shaft of which extends in the direction of one of the longitudinal beams 311 and is in driving connection with this longitudinal beam 311. When the suspension lifting driving motor is started, the output shaft thereof can drive the suspension mechanism 300 to rotate around the axis parallel to the hollow shaft, so that the height of the suspension mechanism 300 can be adjusted, that is, the suspension mechanism can be at least switched from the high position to the low position and from the low position to the high position, and the height of the chassis 100 can be adjusted in the lifting process of the suspension mechanism 300. Although in this example the longitudinal beams are used as the first part of the suspension means or some of the structures of the first part, in other examples other alternative structures may be used as the first part of the suspension means. Furthermore, the second part of the suspension mechanism is not limited to only comprising the suspension hoist drive motor, but may also comprise other structures, such as an auxiliary transmission structure.

Specifically, in some examples, a through hole may be formed in the longitudinal beam 311, a diameter of the through hole near the outer side portion is smaller than a diameter of the through hole near the inner side portion, an output shaft of the suspension lifting drive motor is mounted on a portion of the through hole near the outer side through a first bearing, and a hollow shaft is mounted on a portion of the through hole near the inner side through a second bearing. It should be understood that the first bearing and the second bearing may or may not be coaxially arranged, depending on the actual design.

In other embodiments, to implement the second variant of the vehicle in an automatic manner, the locking portion between the first part 330 and the second part 340 may be replaced by a slip ring structure provided with a rotary electrical connection, which may be driven by a driving device, and when it is necessary to adjust the rotation angle between the first part 330 and the second part 340, it may be achieved by controlling the relative rotation of the slip ring structure. For example, in some examples, the slip ring structure includes an inner ring and an outer ring that are relatively rotatable, and the inner ring and the outer ring can ensure electrical contact in both a stationary state and a rotating state. It will be readily appreciated that when installed, the outer ring is fixedly connected to one of the first and

second portions

330, 340 and correspondingly, the inner ring is fixedly connected to the other of the first and

second portions

330, 340, although the fixed connection may be a direct fixed connection or an indirect fixed connection via intermediate components.

Further, other auxiliary transmission structures, such as a link structure, a rack and pinion structure, etc., may be added to assist in the conversion of the angle between the first portion 330 and the second portion 340.

Further, in the example where the position of the suspension mechanism 300 is changed by applying the driving force, whether or not the driving force itself is provided may serve as locking of the first and second portions. For example, the suspension elevation drive motor itself may serve as a locking portion for locking the first and second portions.

It should be understood that the above two variants can be used alone or in combination. Obviously, when the two deformation modes are used independently, the chassis of the vehicle has at least two different heights, and the gravity center of the vehicle can be positioned at two different positions; when the two variants are combined, the chassis of the vehicle can have at least four heights, so that the center of gravity of the vehicle can be at least in four different positions.

Finally, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also include such advantages, and not all embodiments describe all of the advantages of the invention in detail, and all advantages resulting from the technical features of the embodiments should be construed as advantages which distinguish the invention from the prior art, and are within the scope of the invention.

Claims

1. A lift assembly for connecting a suspension mechanism to a chassis of a vehicle, comprising: a multi-link mechanism and a deformation driving mechanism;

the first end of the multi-link mechanism is hinged with the chassis, and the second end of the multi-link mechanism is hinged with the suspension mechanism;

the deformation driving mechanism is in transmission connection with the multi-link mechanism and is used for driving the multi-link mechanism to drive the chassis to move up and down.

2. The lift device of claim 1, wherein the multi-link mechanism comprises: the first end of the push rod is used for being hinged with the suspension mechanism, the second end of the push rod is hinged with the first end of the rocker arm, the second end of the rocker arm is hinged with the first end of the lifting arm, and the second end of the lifting arm is used for being hinged with the chassis.

3. The lifting device of claim 2, further comprising: and the first end of the vibration reduction mechanism is hinged with the rocker arm, and the second end of the vibration reduction mechanism is used for being fixed with the chassis.

4. The lifting device as claimed in claim 3, wherein the rocker arm is of a triangular structure, and the second end of the push rod, the first end of the lifting arm and the first end of the damping mechanism are respectively hinged at three vertices of the triangular structure.

5. The lifting device as claimed in any one of claims 2 to 4, wherein the deformation driving mechanism comprises a chassis lifting driving motor fixed to the suspension mechanism for driving the push rod to rotate.

6. The lifting device as claimed in any one of claims 2 to 4, wherein the deformation driving mechanism comprises a chassis lifting driving motor fixed on the chassis for driving the lifting arm to rotate.

7. The lift device of claim 1, wherein the deformation drive mechanism comprises: an upper support arm and a lead screw; the first end of going up the support arm with many link mechanism's first end is articulated, go up the second end of support arm with the nut of lead screw is fixed, the screw drive of lead screw the nut motion of lead screw, the nut of lead screw drives go up the support arm motion, the motion of going up the support arm drives many link mechanism motion.

8. The lift device of claim 7, wherein the multi-link mechanism further comprises a suspension having a first end for articulation of the suspension mechanism;

the deformation driving mechanism further comprises a lower supporting arm, the first end of the lower supporting arm is hinged with the second end of the suspension, and the second end of the lower supporting arm is fixed with the nut of the lead screw.

9. The lift device of claim 8, wherein the suspension comprises: the suspension device comprises a suspension upper arm, a suspension lower arm, a first connecting arm and a second connecting arm;

the first connecting arm is used for being fixed with the suspension mechanism, and the second connecting arm is used for being fixed with the chassis;

the first end of the upper suspension arm is hinged with the top end of the first connecting arm, and the second end of the upper suspension arm is hinged with the top end of the second connecting arm;

the first end of the suspension lower arm is hinged with the bottom end of the first connecting arm, and the second end of the suspension lower arm is hinged with the bottom end of the second connecting arm;

and the first end of the lower supporting arm is hinged with the second connecting arm.

10. The lift mechanism of claim 9, wherein the upper suspension arm, the lower suspension arm, the first connecting arm, and the second connecting arm form a parallelogram structure.

11. The lift device recited in claim 9 wherein said first link arm is integrally formed as a single piece with a portion of said suspension mechanism.

12. The lift device recited in claim 9 wherein said multi-bar linkage includes a push rod having a first end for articulation with said suspension mechanism and a first end for simultaneous articulation with a top end of said first link arm.

13. The lift device of claim 11, wherein a first end of the lower support arm is hingedly coupled to a second end of the second link arm.

14. The lifting device according to any one of claims 9 to 13, further comprising: a bottom plate and a support frame; the support frame with the second linking arm is fixed on the bottom plate, just the support frame is located the second linking arm is kept away from one side of first linking arm, the support frame is used for installing chassis lift driving motor.

15. The lift device of claim 14, further comprising an articulated arm disposed between the second link arm and the support frame and secured to the base plate; the second end of the lifting arm is hinged with the hinged arm.

16. The lift mechanism of claim 15, wherein a first end of the upper support arm is hinged between the first end of the lift arm and the second end of the lift arm, and wherein the hinge point of the upper support arm to the lift arm is proximate the second end of the lift arm.

17. The lift device of claim 15, wherein the second link arm, support bracket, hinged arm, and base plate are an integrally formed unitary piece.

18. A vehicle, characterized by comprising: the device comprises a chassis, a plurality of suspension mechanisms, a plurality of wheel sets and a lifting device; the wheel sets are respectively arranged on two opposite sides of the chassis; the wheel set includes: the wheel shaft and the wheels are sleeved on the wheel shaft, each wheel shaft is rotatably connected with the corresponding suspension mechanism, and the suspension mechanisms are connected with the chassis through the lifting device;

the lifting device comprises: a multi-link mechanism and a deformation driving mechanism;

19. The vehicle of claim 18, characterized in that the multi-link mechanism comprises: the first end of the push rod is used for being hinged with the suspension mechanism, the second end of the push rod is hinged with the first end of the rocker arm, the second end of the rocker arm is hinged with the first end of the lifting arm, and the second end of the lifting arm is used for being hinged with the chassis.

20. The vehicle of claim 19, further comprising: and the first end of the vibration reduction mechanism is hinged with the rocker arm, and the second end of the vibration reduction mechanism is used for being fixed with the chassis.

21. The vehicle of claim 20, wherein the rocker arm is of a triangular configuration, and the second end of the push rod, the first end of the lift arm, and the first end of the damping mechanism are each hinged at three vertices of the triangular configuration.

22. The vehicle of any one of claims 19 to 21, characterized in that the deformation driving mechanism comprises a chassis lift driving motor fixed to the suspension mechanism for driving the push rod to rotate.

23. The vehicle of any one of claims 19 to 21, characterized in that the deformation drive mechanism comprises a chassis lift drive motor fixed to the chassis for driving rotation of the lift arm.

24. The vehicle of claim 18, characterized in that the deformation drive mechanism comprises: an upper support arm and a lead screw; the first end of going up the support arm with many link mechanism's first end is articulated, go up the second end of support arm with the nut of lead screw is fixed, the screw drive of lead screw the nut motion of lead screw, the nut of lead screw drives go up the support arm motion, the motion of going up the support arm drives many link mechanism motion.

25. The vehicle of claim 24, characterized in that the multi-link mechanism further comprises a suspension having a first end for articulation of the suspension mechanism;

26. The vehicle of claim 25, characterized in that the suspension comprises: the suspension device comprises a suspension upper arm, a suspension lower arm, a first connecting arm and a second connecting arm;

27. The vehicle of claim 26, characterized in that the upper suspension arm, the lower suspension arm, the first connecting arm and the second connecting arm form a parallelogram structure.

28. The vehicle of claim 26, characterized in that the first connecting arm is an integrally formed one-piece member with a portion of the suspension mechanism.

29. The vehicle of claim 26, characterized in that the multi-link mechanism comprises a push rod having a first end for articulation with the suspension mechanism and a first end for simultaneous articulation with a top end of the first connecting arm.

30. The vehicle of claim 28, characterized in that the first end of the lower support arm is hinged to the second end of the second connecting arm.

31. The vehicle of any of claims 26-30, further comprising: a bottom plate and a support frame; the support frame with the second linking arm is fixed on the bottom plate, just the support frame is located the second linking arm is kept away from one side of first linking arm, the support frame is used for installing chassis lift driving motor.

32. The vehicle of claim 31, further comprising an articulated arm disposed between the second connecting arm and a support bracket and secured to the floor; the second end of the lifting arm is hinged with the hinged arm.

33. The vehicle of claim 32, characterized in that a first end of the upper support arm is hinged between a first end of the lift arm and a second end of the lift arm, and the hinge point of the upper support arm and the lift arm is proximate the second end of the lift arm.

34. The vehicle of claim 32, characterized in that the second connecting arm, the support bracket, the hinge arm, and the floor are an integrally formed unitary piece.

35. The vehicle of claim 18, characterized in that the number of wheel sets is four.

36. The vehicle of claim 18, wherein the wheels are mecanum wheels.

37. The vehicle of claim 18, characterized in that the wheel set further comprises: a travel drive mechanism;

the walking driving mechanism is in transmission connection with the wheel shaft and is used for driving the wheel shaft to drive the wheels to rotate.

38. The vehicle of claim 37, further comprising a steering mechanism drivingly connected to the suspension mechanism for selectively driving rotation of the suspension mechanism to rotate the wheel about an axis of rotation perpendicular to the axle.

39. The vehicle of claim 38, characterized in that the suspension mechanism comprises: a cross beam and two longitudinal beams; the two longitudinal beams are respectively arranged on the inner side and the outer side of the wheel and are rotationally connected with the wheel shaft; the cross beam is arranged between the two longitudinal beams and fixed with the two longitudinal beams; the steering mechanism is in transmission connection with the cross beam; the lifting device is hinged with the cross beam.

40. The vehicle of any of claims 18, 35-39, characterized in that a pan-tilt is mounted on the chassis.

41. The vehicle of any one of claims 18 and 35-39, characterized in that the chassis comprises an upper mounting plate and a lower mounting plate which are oppositely arranged, and a part of the lifting device is accommodated in an accommodating space formed by the upper mounting plate and the lower mounting plate.