Walking chassis and control method

Abstract

The invention discloses a walking chassis and a control method, the walking chassis comprises a chassis main body structural member, a front axle and a rear axle, a horizontal tilt angle sensor is installed on the surface of the chassis main body structural member, the front axle and the rear axle are both integrated axles and are respectively hinged with the chassis main body structural member, double-acting oil cylinders are arranged on two sides of the top of the front axle, and the double-acting oil cylinders are connected with the chassis main body structural member. One end of the double-acting oil cylinder is hinged with the front axle, and the other end is hinged with the chassis main body structural member; the single-acting oil cylinders are arranged at the two ends of the upper surface of the rear axle and fixed to the chassis body structural part. The horizontal inclination angle sensors are adopted to detect the inclination conditions of the left side and the right side of the chassis body, the extending lengths of the single-acting oil cylinders on the left side and the right side are controlled according to the horizontal inclination angle conditions, the chassis is in a horizontal state in the left-right direction, and therefore it is guaranteed that an upper vehicle and a working table connected with the chassis are always in the horizontal state in the left-right direction; the driving feeling of operators is improved, and the stability and operation safety of the whole machine are improved.

Description

Technical Field

[0001] The present invention relates to a walking chassis, and particularly to a walking chassis and a control method. Background Art

[0002] Off-road scissor forklifts are an important branch of scissor-type aerial work platforms. Compared with conventional scissor forklifts, they have the characteristics of large load capacity, wide platform, large number of passengers, and strong road adaptability. They are mainly used in the construction and maintenance of construction venues, factories, and bridges. Most of the time, the ground of the working site is uneven, with many potholes and obstacles. And the vehicle needs to frequently change its working position or transfer during operation. Therefore, higher requirements are put forward for the off-road ability of the vehicle and the safety of the lifting operation on complex roads.

[0003] For existing off-road scissor forklifts, one type uses a fixed chassis, where the axle is rigidly connected to the chassis. When driving on an uneven road surface, the situation may occur that the tires cannot touch the ground simultaneously, and the suspended tires have the phenomenon of idling, resulting in insufficient driving force of the vehicle. At the same time, the chassis will tilt with the undulation of the ground, leading to the tilt of the workbench surface in the left and right directions. When the operator stands on the tilted workbench surface, it affects the driving experience of the operator when the boom is not lifted. In the state where the boom is lifted, the tilt of the workbench surface affects the safety of the operator's aerial work.

[0004] Another type has a floating front axle, and the rear axle is rigidly connected to the chassis. The front axle uses a single or double balance cylinders to achieve the up and down floating of the axle. When the ground is uneven, there are height differences in the contact surfaces of the four tires. At this time, the front axle floats to adapt to the road surface, which can ensure the grounding of the four tires to a certain extent. However, due to the rigid connection between the rear axle and the chassis, the chassis will tilt left and right, resulting in the tilt of the upper workbench surface connected to it. When the operator stands on the tilted workbench surface, it affects the driving experience of the operator when the boom is not lifted. In the state where the boom is lifted, the tilt of the workbench surface affects the safety of the operator's aerial work. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a walking chassis and a control method, which can achieve the left and right level of the chassis while ensuring that the rear wheels are always in contact with the ground.

[0006] Technical Solution: The present invention includes a chassis main structural member, a front axle, and a rear axle. A horizontal inclination sensor is installed on the surface of the chassis main structural member. Both the front axle and the rear axle adopt an integral axle. The front axle and the rear axle are respectively hinged to the chassis main structural member. Double-acting cylinders are arranged on both sides of the top of the front axle. One end of the double-acting cylinder is hinged to the front axle, and the other end is hinged to the chassis main structural member. Single-acting cylinders are arranged at both ends of the upper surface of the rear axle, and the single-acting cylinders are fixed to the chassis main structural member.

[0007] Pressure plates are provided at both ends of the upper surface of the rear axle, which are located directly below the single-acting cylinder. When the cylinder rod of the single-acting cylinder is extended, it presses against the pressure plates. In the initial horizontal state, the cylinder rods of the left and right single-acting cylinders are both in an extended state with the same extension length, and press against the left and right pressure plates to keep the rear axle in a relatively fixed state.

[0008] Hydraulic motors are fixed on both sides of the rear axle, and the hydraulic motors are connected to the rear wheels.

[0009] The rear axle is hinged to the main structural parts of the chassis through a pin.

[0010] A slideway connected to the scissor arm is arranged on the main chassis structure above the rear axle for installing the scissor arm.

[0011] The front axle is hinged to the main chassis structure through an axle.

[0012] A left steering knuckle and a right steering knuckle are arranged on the front axle, a steering tie rod is hinged between the left steering knuckle and the right steering knuckle, and a steering cylinder is hinged between the front axle and the right steering knuckle.

[0013] A left hydraulic motor is fixed on the left steering knuckle, and the left hydraulic motor is connected to the left transition connection plate. A right hydraulic motor is fixed on the right steering knuckle, and the right hydraulic motor is connected to the right transition connection plate.

[0014] A vehicle ladder is installed on one side of the chassis main structure.

[0015] A method for controlling a walking chassis, comprising:

[0016] When there is a height difference between the front wheels and the ground, the cylinder rods of the double-acting cylinders on the left and right sides of the front axle are controlled to extend and retract, and the front axle rotates around the axis to achieve floating of the front axle, so that the front wheels are always in contact with the ground;

[0017] When there is a height difference between the rear wheels and the ground, while ensuring that the two rear wheels are always in contact with the ground, the chassis is adjusted to left and right level by controlling the extension length of the single-acting cylinders on both sides according to the left and right inclination of the chassis body detected by the horizontal inclination sensor.

[0018] Beneficial effects: The present invention has the following advantages:

[0019] 1) The scissor-type aerial work platform walking chassis provided by the present invention has a floating front axle and a rear axle, and both are integrated axles with simple structure, high strength and good rigidity.

[0020] 2) Because a slideway connecting the scissor arms is arranged on the chassis structure above the rear axle, the space available for the cylinder installation is small, and single-acting cylinders are used on the left and right sides. The structure is simple and the cost is low. The single-acting cylinders can solve the cylinder installation space while realizing active floating of the rear axle.

[0021] 3) The floating of the front axle and the rear axle can be controlled separately, which can ensure that the four tires are always in contact with the ground at the same time, guarantee the driving force of the vehicle, and improve the driving performance.

[0022] 4) Due to the large front and rear wheelbase of the whole vehicle and the small left and right wheelbase, the whole vehicle is more sensitive to the left and right inclination. The floating of the rear axle is associated with the horizontal inclination angle of the chassis in the left and right directions. A horizontal inclination sensor is used to detect the inclination of the left and right sides of the chassis main body, and the extension length of the single-acting cylinders on the left and right sides is controlled according to the horizontal inclination condition, so as to make the left and right directions of the chassis in a horizontal state, thus ensuring that the upper vehicle and the workbench surface connected to the chassis are always in a horizontal state in the left and right directions, improving the driving experience of the operator, and enhancing the stability and operation safety of the whole machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the overall structure of the chassis of the present invention;

[0024] Figure 2 is a schematic diagram of the disassembled chassis of the present invention;

[0025] Figure 3 is a schematic diagram of the connection of the steering structure of the present invention;

[0026] Figure 4 is a schematic diagram of the overall structure of the chassis of the present invention applied to a scissor-type aerial work platform. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] Embodiment 1

[0029] As Figure 1 shown, the walking chassis of this embodiment includes a chassis main structure member 4, a front axle 7 and a rear axle 9. A ladder 1 is installed beside the chassis main structure member 4, and a horizontal inclination sensor 8 is installed on the surface of the chassis main structure member 4. The horizontal inclination sensor 8 can detect the horizontal inclination of the chassis main structure member 4; Tires 3 are installed on both sides of the front axle 7 and the rear axle 9.

[0030] As Figure 2 shown, the front axle 7 is an integral axle. The front axle 7 is hinged to the chassis main structure member 4 through a shaft 5. Double-acting cylinders are arranged on both sides of the top of the front axle 7, including a first double-acting cylinder 6 and a second double-acting cylinder 17. One end of the first double-acting cylinder 6 and the second double-acting cylinder 17 is hinged to the front axle 7 through a shaft, and the other end is hinged to the chassis main structure member 4 through a shaft. When the ground on the left side of the front wheel is high and the ground on the right side is low, the piston rod of the left double-acting cylinder retracts and the piston rod of the right double-acting cylinder extends, and the middle of the front axle 7 rotates around the shaft 5 to realize the floating of the front axle 7; when the ground on the right side is high and the ground on the left side is low, the floating direction of the front axle is opposite to the above.

[0031] The rear axle 9 is an integrated axle, and hydraulic motors 16 are fixed on the left and right sides of the rear axle 9 respectively. The hydraulic motors 16 are connected to the rear wheels. The rear axle 9 is hinged to the chassis main structure 4 through a pin shaft 2. Single-acting cylinders are arranged at both ends of the upper surface of the rear axle 9, including a first single-acting cylinder 11 and a second single-acting cylinder 18. The first single-acting cylinder 11 and the second single-acting cylinder 18 are fixed to the chassis main structure 4 by bolts. The first single-acting cylinder 11 and the second single-acting cylinder 18 are provided with pressure plates 10 at the bottom. In the initial horizontal state, the cylinder rods of the left and right single-acting cylinders are in an extended state, and the extended lengths are consistent, and they support the left and right pressure plates 10 to keep the rear axle 9 in a relatively fixed state. When the ground is high on the left side and low on the right side of the rear wheel, the horizontal inclination sensor 8 detects that the chassis body is tilted to the right. In order to keep the chassis horizontal, the cylinder rods of the single-acting cylinders on both sides always keep against the pressure plate 10. At this time, the extension length of the cylinder rod of the right single-acting cylinder becomes longer, and the extension length of the cylinder rod of the left single-acting cylinder becomes shorter. The rear axle 9 rotates around the pin 2 in the middle to adjust the chassis body to a horizontal state; when the ground is high on the right side and low on the left side of the rear wheel, the floating direction of the rear axle is opposite to the above.

[0032] The rear axle 9 is of an integrated type with a simple structure and good structural rigidity and strength. A slideway connecting the scissor arms 02 is arranged at the main chassis structure 4 above the rear axle 9. The cylinder installation space is small, and single-acting cylinders are used on the left and right sides. The structure is simple and the cost is low. The single-acting cylinders can solve the cylinder installation space while realizing active floating of the rear axle.

[0033] like Figure 3 As shown, the front axle 7 is provided with a left steering knuckle 14 and a right steering knuckle 20, a steering tie rod 19 is connected between the left steering knuckle 14 and the right steering knuckle 20, and the two ends of the steering tie rod 19 are respectively hinged to the left steering knuckle 14 and the right steering knuckle 20. The front axle 7 is hinged to the upper and lower ends of the steering knuckles through shafts, a left hydraulic motor 13 is fixed to the left steering knuckle 14, and a right hydraulic motor 21 is fixed to the right steering knuckle 20, the transmission shaft of the left hydraulic motor 13 is connected to the left transition connection plate 15, and the transmission shaft of the right hydraulic motor 21 is connected to the right transition connection plate 22, and the outer rings of the transition connection plates on both sides are respectively connected to the tires 3, and a steering cylinder 12 is connected between the front axle 7 and the right steering knuckle 20, and the two ends of the steering cylinder 12 are respectively hinged to the front axle 7 and the right steering knuckle 20 through shafts.

[0034] When it is necessary to turn left, the rod of the steering cylinder 12 extends, driving the right steering knuckle 20 to swing to the left, and the right steering knuckle 20 drives the left steering knuckle 14 to swing to the left through the steering tie rod 19, thereby realizing the left steering function of the entire vehicle; when it is necessary to turn right, the rod of the steering cylinder 12 retracts, ultimately driving the steering knuckles on both sides to swing to the right, thereby realizing the right steering function of the entire vehicle.

[0035] As Figure 4 Figure 4 is a schematic diagram of applying the chassis of this embodiment to a scissor-type aerial work platform. The scissor-type aerial work platform includes a working platform 01, scissor arms 02, a walking chassis 03, and a box 04. The scissor arms 02 connect the working platform 01 and the walking chassis 03. Boxes 04 are arranged on both sides of the scissor arms 02, and liquid and electrical components are arranged inside the boxes 04. The scissor arms 02 are driven by lifting cylinders to lift up and down. The front end of the bottommost link of the scissor arms 02 is connected to the chassis in a hinged form, and the rear end is connected to the slideway arranged on the chassis in a sliding manner. The front end of the uppermost link of the scissor arms 02 is connected to the working platform 01 in a hinged form, and the rear end is connected to the slideway arranged at the bottom of the working platform 01 in a sliding manner. When the chassis main body tilts, the connected scissor arms 02 and the working platform 01 tilt accordingly.

[0036] The front axle and the rear axle of this embodiment are both floating type and are hinged to the vehicle frame through pin shafts. Two balance cylinders are arranged on each of the front axle and the rear axle. Among them, the front axle uses a double-acting balance cylinder, and the rear axle uses a single-acting balance cylinder. When the ground is uneven, the front axle and the rear axle can ensure that all four tires are always in contact with the ground through the floating of the axles, ensuring the driving force of the vehicle and improving the driving performance. Due to the large front and rear wheelbase of the whole vehicle and the small wheelbase in the left and right directions, the whole vehicle is more sensitive to tilting in the left and right directions. The simultaneous floating of the front axle and the rear axle can keep the left and right directions of the chassis always in a horizontal state, so as to ensure that the upper vehicle and the working table surface connected to the chassis are always in a horizontal state in the left and right directions, improving the stability of the whole machine and the operation safety.

[0037] The front axle and the rear axle of this embodiment are both controlled to float independently. The floating situation of the front axle is related to the height difference of the ground where the two front wheels are located. According to the ground tilt situation of the front wheels, the rod of the double-acting cylinders on both sides of the front axle is controlled to extend and retract, so as to ensure that the two front wheels are always in contact with the ground; when there is a height difference between the ground where the two rear wheels are located, while ensuring that the two rear wheels are always in contact with the ground, according to the tilt situation of the left and right sides of the chassis main body detected by the horizontal inclination sensor, the extension length of the single-acting cylinders on both sides is controlled to change, so as to adjust the chassis to be horizontal in the left and right directions.

[0038] Embodiment 2

[0039] The control method of the walking chassis of this embodiment includes:

[0040] When there is a height difference in the ground where the front wheels are located, control the rod of the double-acting cylinders on both sides of the front axle to extend and retract, and the front axle rotates around the axis to realize the floating of the front axle, so that the front wheels always contact the ground;

[0041] When there is a height difference on the ground where the rear wheels are located, while ensuring that the two rear wheels are always in contact with the ground, according to the inclination of the left and right sides of the chassis main body detected by the horizontal inclination sensor, by controlling the change in the extension length of the single-acting cylinders on both sides, the chassis is adjusted to be horizontally level on the left and right.

Claims

1. A walking chassis, characterized in that, It includes a chassis main structure, a front axle and a rear axle. A horizontal inclination sensor is installed on the surface of the chassis main structure. The front axle and the rear axle both adopt an integrated axle. The front axle and the rear axle are respectively hinged to the chassis main structure. Double-acting cylinders are arranged on both sides of the top of the front axle, one end of the double-acting cylinder is hinged to the front axle, and the other end is hinged to the chassis main structure. Single-acting cylinders are arranged at both ends of the upper surface of the rear axle, and the single-acting cylinders are fixed on the chassis main structure.

2. The walking chassis according to claim 1, wherein, Both ends of the upper surface of the rear axle are provided with pressure plates, which are located just below the single-acting oil cylinder. When the cylinder rod of the single-acting oil cylinder is extended, the pressure plates are supported.

3. The walking chassis according to claim 1, characterized in that, Hydraulic motors are respectively fixed on both sides of the rear axle, and the hydraulic motors are connected to the rear wheels.

4. The walking chassis according to claim 3, characterized in that, The rear axle is hinged to the chassis main structure through a pin shaft.

5. The walking chassis according to claim 4, characterized in that, A slideway connected to the scissor arms is arranged at the chassis main structure above the rear axle.

6. The walking chassis according to claim 1, wherein The front axle is hinged to the chassis main structure through an axle.

7. The walking chassis according to claim 6, characterized in that, A left steering knuckle and a right steering knuckle are arranged on the front axle, a steering tie rod is hinged between the left steering knuckle and the right steering knuckle, and a steering oil cylinder is hinged between the front axle and the right steering knuckle.

8. The walking chassis according to claim 7, wherein, A left hydraulic motor is fixed on the left steering knuckle, and the left hydraulic motor is connected to the left transition connection plate. A right hydraulic motor is fixed on the right steering knuckle, and the right hydraulic motor is connected to the right transition connection plate.

9. The walking chassis according to claim 1, wherein A vehicle ladder is installed on one side of the chassis main structure.

10. A control method for a walking chassis according to any one of claims 1 to 9, characterized in that, include: When there is a height difference between the front wheels and the ground, the cylinder rods of the double-acting cylinders on the left and right sides of the front axle are controlled to extend and retract, and the front axle rotates around the axis to achieve floating of the front axle, so that the front wheels are always in contact with the ground; When there is a height difference between the rear wheels and the ground, while ensuring that the two rear wheels are always in contact with the ground, the chassis is adjusted to left and right level by controlling the extension length of the single-acting cylinders on both sides according to the left and right inclination of the chassis body detected by the horizontal inclination sensor.

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