A grab driver's cabin lifting mechanism, control system and control method

Abstract

The present application belongs to the technical field of mechanical engineering, and particularly relates to a lifting mechanism, a control system and a control method for a driver's cabin of a grab machine. A hinge point A on a lifting frame of the driver's cabin is hinged to a secondary small arm, and the secondary small arm is hinged to a hinge point J of a triangular connecting frame. A hinge point B on the lifting frame of the driver's cabin is hinged to a secondary large arm, and the secondary large arm is hinged to a hinge point H of the triangular connecting frame. A hinge point C on a connecting support is hinged to a primary small arm, and a hinge point E on the connecting support is hinged to a primary large arm. The primary small arm is hinged to the hinge point H of the triangular connecting frame, and the primary large arm is hinged to a hinge point I of the triangular connecting frame. A power device is used to drive the two-stage parallel four-bar linkage lifting mechanism to move, so as to realize the translation of the driver's cabin, form a driver's cabin motion envelope in a space plane, and adjust the observation field of view in the driver's cabin to be optimal in real time according to different heights, distances, nearness and remoteness of the material piles in loading and unloading operations, so as to meet the switching of different loading and unloading scene working conditions.

Description

Technical Field

[0001] This invention belongs to the field of mechanical engineering technology, and in particular relates to a lifting mechanism, control system and control method for a material handling machine driver's cab. Background Technology

[0002] In bulk material loading and unloading operations at railway freight stations, ports, and docks, material handling machines are widely used. However, during use, the height, distance, and proximity of the objects being loaded and unloaded are often different. The operator's field of vision in the fixed driver's cab is difficult to meet the switching of different loading and unloading scenarios. The limited field of vision can also cause varying degrees of collision and damage to the surrounding area of ​​the material pile (such as the ship, carriage, personnel, etc.), which can easily lead to safety accidents.

[0003] In existing technologies, structures with adjustable driver's cabs generally achieve this through a single-stage lifting mechanism. For example, patent CN203391876U discloses a material handling machine equipped with a device for freely lifting and lowering the driver's cab. The lifting cab device includes a driver's cab assembly, a driver's cab support, an upper connecting rod, a lower connecting rod, a lifting support, and a lifting cylinder. The lifting support is mounted on a corresponding position on the platform assembly. One end of the upper and lower connecting rods is mounted on a corresponding position on the lifting support. The steel cylinder end of the lifting cylinder is connected to the lifting support, and the other end is connected to the lower connecting rod. The upper fulcrum of the driver's cab support is connected to the other end of the upper connecting rod, and the lower fulcrum is connected to the other end of the lower connecting rod. The driver's cab assembly is mounted on the driver's cab support. Similar to the above technologies, the adjustable range of a single lifting mechanism is limited, thus restricting the field of vision in both near and far directions. Summary of the Invention

[0004] To address the technical problems existing in the background art, the present invention provides a lifting mechanism for the driver's cab of a material handling machine, a control system, and a control method.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A lifting mechanism for the driver's cab of a material handling machine.

[0007] The lifting mechanism includes a driver's cab, a driver's cab lifting frame, a secondary forearm, a secondary boom, a triangular connecting frame, a primary forearm, a primary boom, a connecting support, and a power unit.

[0008] The driver's cab is fixed on the driver's cab frame. Hinge point A on the driver's cab frame is hinged to one end of the secondary boom, and the other end of the secondary boom is hinged to hinge point J of the triangular connecting frame. Hinge point B on the driver's cab frame is hinged to one end of the secondary boom, and the other end of the secondary boom is hinged to hinge point H of the triangular connecting frame. The driver's cab frame, secondary boom, secondary boom, and triangular connecting frame form a secondary parallel four-bar linkage lifting mechanism.

[0009] The hinge point C on the connecting support is hinged to one end of the primary forearm, and the hinge point E on the connecting support is hinged to one end of the primary boom; the other end of the primary forearm is hinged to the hinge point H of the triangular connecting frame, and the other end of the primary boom is hinged to the hinge point I of the triangular connecting frame; the connecting support, the primary forearm, the primary boom, and the triangular connecting frame form a primary parallel four-bar linkage lifting mechanism.

[0010] The power unit is used to drive the first-stage parallel four-bar linkage lifting mechanism and the second-stage parallel four-bar linkage lifting mechanism to achieve translation of the driver's cab.

[0011] Optionally, the power unit includes a secondary hydraulic cylinder and a primary hydraulic cylinder. The two ends of the secondary hydraulic cylinder are respectively connected to the F hinge point of the secondary boom and the J hinge point of the triangular connecting frame; the two ends of the primary hydraulic cylinder are respectively connected to the D hinge point of the connecting support and the G hinge point of the primary forearm.

[0012] Optionally, the F hinge point of the secondary boom is located in the middle of the secondary boom; the G hinge point of the primary forearm is located on the side of the primary forearm near the triangular connecting frame; the D hinge point of the connecting support is located between the C hinge point and the E hinge point of the connecting support, and on the side near the E hinge point.

[0013] A control system for the lifting mechanism of the operator's cab of a material handling machine, the control system comprising a gear pump, a safety valve, an unloading directional valve, a three-position four-way directional valve, a hydraulic lock, an accumulator, a primary cylinder, a secondary cylinder, a hydraulic resistance valve, a check valve, a normally closed directional valve, an emergency switch, a two-position three-way directional valve, a hydraulic oil tank, and an electronic controller.

[0014] The gear pump outputs pressurized oil, which is connected to the inlets of the safety valve, unloading directional valve, three-position four-way directional valve, and two-position three-way directional valve, respectively. The working port of the three-position four-way directional valve is connected to the inlet of the hydraulic lock, and the outlet of the hydraulic lock is connected to the large and small chambers of the first-stage cylinder, respectively. The working port of the two-position three-way directional valve is connected to the accumulator, the small chamber of the second-stage cylinder, and the hydraulic resistance via a check valve, respectively. The outlet of the hydraulic resistance is connected to the inlet of the normally closed directional valve and the emergency switch, respectively. The outlets of the safety valve, unloading directional valve, normally closed directional valve, and emergency switch, the return ports of the three-position four-way directional valve and the two-position three-way directional valve, and the large chamber of the second-stage cylinder converge and flow into the hydraulic oil tank. The signal terminals of the solenoid valves used for electrical control are all connected to the electronic controller.

[0015] A control method for a control system of a lifting mechanism in the driver's cab of a material handling machine is disclosed. The electronic controller issues commands to energize and de-energize the two signal terminals of a three-position four-way directional valve, thereby controlling the extension, retraction, and stop of the first-stage hydraulic cylinder. The electronic controller also issues commands to energize and de-energize the signal terminals of a two-position three-way directional valve or a normally closed directional valve, thereby controlling the extension, retraction, and stop of the second-stage hydraulic cylinder. Furthermore, the electronic controller issues commands to energize and de-energize the unloading solenoid valve, ensuring that the gear pump is in an unloaded state except when the first-stage hydraulic cylinder is extending or retracting and the second-stage hydraulic cylinder is retracting. A hydraulic lock is used to lock the first-stage hydraulic cylinder, and a check valve is used to lock the second-stage hydraulic cylinder. The small chamber of the second-stage hydraulic cylinder is connected to an accumulator for hydraulic damping to eliminate pulsations during the start-up or stop of the lifting mechanism.

[0016] A control method for the control system of the lifting mechanism of the operator's cab of a material handling machine: When the operator's cab needs to be lowered, an instruction is issued by the electronic controller to energize only the normally closed directional valve. The gravity of the operator's cab is transmitted to the secondary hydraulic cylinder. The oil in the small chamber of the secondary hydraulic cylinder is pressurized and flows back to the oil tank through the hydraulic resistance and the normally closed directional valve. The oil with a certain back pressure in the hydraulic oil tank is replenished to the large chamber of the secondary hydraulic cylinder, realizing the extension of the secondary hydraulic cylinder. The gear pump is in an unloaded state through the unloading directional valve. Gravity is used to realize the autonomous extension of the secondary hydraulic cylinder to lower the operator's cab.

[0017] A control method for the control system of the lifting mechanism of the driver's cab of a material handling machine: when the whole vehicle loses power due to a malfunction, the pressure oil in the small chamber of the secondary oil cylinder flows back to the oil tank through the hydraulic resistance and the emergency switch by switching the emergency switch, and the secondary oil cylinder is autonomously extended by gravity to lower the driver's cab.

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

[0019] This invention designs a lifting mechanism and control system for the driver's cab of a material handling machine. It employs a dual lifting mechanism: a primary lifting mechanism adjusts the driver's cab's near and far field of vision; a secondary lifting mechanism adjusts the driver's cab's high and low field of vision. By adjusting the movements of the primary and secondary lifting mechanisms, a motion envelope diagram of the driver's cab is formed in the spatial plane. Based on the varying heights, distances, and nearness of the material pile during loading and unloading operations, the driver's cab's field of vision is adjusted in real time to achieve the optimal viewing angle, thus satisfying the switching needs of different loading and unloading scenarios.

[0020] The driver's cab lifting mechanism is hydraulically controlled. The movement of the primary and secondary lifting mechanisms is driven by hydraulic cylinders, which have a locking function to ensure that the mechanism does not sink in any state. The hydraulic lock, check valve, and accumulator connected to the control system realize hydraulic shock absorption, ensuring smooth operation of the mechanism without impact and improving ride comfort. At the same time, the secondary lifting mechanism adjusts the driver's cab descent by gravity autonomously, without the need for an external power source, which is energy-saving and environmentally friendly. In addition, the control system is equipped with an emergency switch for lowering the driver's cab. In emergency situations, such as when the vehicle loses power due to a malfunction, the emergency switch located in the driver's cab can ensure that the driver can evacuate safely and quickly. The entire system has low energy consumption, high reliability, and simple operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the lifting mechanism of the operator's cab of the material handling machine in this invention;

[0022] Figure 2 This is a schematic diagram of the lifting mechanism of the operator's cab of the material handling machine in this invention moving to its furthest position in the horizontal direction;

[0023] Figure 3 This is a schematic diagram of the lifting mechanism of the operator's cab of the material handling machine in the present invention moving to the highest position in the vertical direction;

[0024] Figure 4 This is an envelope diagram of the motion trajectory of the driver's cab of the lifting mechanism of the material handling machine in the present invention within a spatial plane;

[0025] Figure 5 This is a schematic diagram of the folding and storage of the driver's cab of the material handling machine driver's cab lifting mechanism in this invention;

[0026] Figure 6 for Figure 5 A schematic diagram showing the intermediate-level lifting mechanism linking the driver's cab to move in a distant direction;

[0027] Figure 7 for Figure 6 A schematic diagram showing the intermediate and secondary lifting mechanisms working in conjunction with the driver's cab to move to the furthest position in a distant direction;

[0028] Figure 8 for Figure 5 A schematic diagram showing the linkage between the secondary and intermediate lifting mechanisms and the driver's cab, indicating a horizontal movement towards a higher position.

[0029] Figure 9 for Figure 8 A schematic diagram showing the intermediate-level lifting mechanism linking the driver's cab to move upwards to the highest position;

[0030] Figure 10 This is a control system diagram of the lifting mechanism of the operator's cab of the material handling machine in this invention.

[0031] Attached reference numerals: 1-Driver's cab, 2-Driver's cab lifting frame, 3-Secondary boom, 4-Secondary boom, 5-Primary boom, 6-Connecting support, 7-Primary cylinder, 8-Primary boom, 9-Triangular connecting frame, 10-Secondary cylinder, 11-Gear pump, 12-Safety valve, 13-Unloading directional valve, 14-Three-position four-way directional valve, 15-Hydraulic lock, 16-Accumulator, 17-Hydraulic resistance, 18-Check valve, 19-Normally closed directional valve, 20-Emergency switch, 21-Two-position three-way directional valve, 22-Electrical controller, 23-Hydraulic oil tank. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0034] Example 1

[0035] like Figures 1-9 As shown, a lifting mechanism for the driver's cab of a material handling machine includes a driver's cab 1, a driver's cab lifting frame 2, two secondary forearms 3, two secondary booms 4, two triangular connecting frames 9, two primary forearms 5, two primary booms 8, a connecting support 6, and a power unit.

[0036] like Figure 1 As shown, the driver's cab 1 is fixed on the driver's cab support frame 2, which has an L-shaped structure. The driver's cab support frame 2 has vertical hinge points A and B. The triangular connecting frame 9 has hinge points J, H, and I arranged in a triangle, with hinge points J and H arranged vertically and hinge points H and I arranged horizontally. The connecting support 6 has horizontally arranged hinge points C, D, and E.

[0037] like Figure 1 As shown, hinge point A on the driver's cab lifting frame 2 is hinged to one end of the secondary boom 3, and the other end of the secondary boom 3 is hinged to hinge point J of the triangular connecting frame 9; hinge point B on the driver's cab lifting frame 2 is hinged to one end of the secondary boom 4, and the other end of the secondary boom 4 is hinged to hinge point H of the triangular connecting frame 9; the driver's cab lifting frame 2, the secondary boom 3, the secondary boom 4, and the triangular connecting frame 9 constitute a secondary parallel four-bar linkage lifting mechanism.

[0038] like Figure 1 As shown, hinge point C on the connecting support 6 is hinged to one end of the first-stage forearm 5, and hinge point E on the connecting support 6 is hinged to one end of the first-stage boom 8; the other end of the first-stage forearm 5 is hinged to hinge point H of the triangular connecting frame 9, and the other end of the first-stage boom 8 is hinged to hinge point I of the triangular connecting frame 9; the connecting support 6, the first-stage forearm 5, the first-stage boom 8, and the triangular connecting frame 9 constitute a first-stage parallel four-bar linkage lifting mechanism.

[0039] In this invention, the power unit is used to drive the first-stage parallel four-bar linkage lifting mechanism and the second-stage parallel four-bar linkage lifting mechanism to achieve translation of the driver's cab.

[0040] like Figure 1 As shown, in this invention, the power unit includes two secondary hydraulic cylinders 10 and one primary hydraulic cylinder 7. The two ends of the secondary hydraulic cylinders 10 are respectively connected to the F hinge point of the secondary boom 4 and the J hinge point of the triangular connecting frame 9. The cylinder body of the secondary hydraulic cylinder 10 is connected to the F hinge point, and the piston rod of the secondary hydraulic cylinder 10 is connected to the J hinge point to ensure the realization of subsequent functions. The two ends of the primary hydraulic cylinder 7 are respectively connected to the D hinge point of the connecting support 6 and the G hinge point of the primary arm 5. The cylinder body of the primary hydraulic cylinder 7 is connected to the D hinge point, and the piston rod of the primary hydraulic cylinder 7 is connected to the G hinge point.

[0041] Furthermore, the F hinge point of the secondary boom 4 is located in the middle of the secondary boom 4; the G hinge point of the primary forearm 5 is located on the side of the primary forearm 5 near the triangular connecting frame 9; the D hinge point of the connecting support 6 is located between the C hinge point and the E hinge point of the connecting support 6, and on the side near the E hinge point.

[0042] In this invention, the parallelogram CEHI forms a first-level parallel four-bar linkage lifting mechanism. By adjusting the extension and retraction of the first-level hydraulic cylinder 7, the driver's cab 1 can be moved in the near and far directions, thereby adjusting the field of view in the near and far directions within the driver's cab.

[0043] In this invention, parallelograms ABHJ form a two-stage parallel four-bar linkage lifting mechanism. By adjusting the extension and retraction of the second-stage hydraulic cylinder 10, the driver's cab 1 can be moved in the height direction, thereby adjusting the field of view in the height direction within the driver's cab.

[0044] This invention designs a lifting mechanism and control system for a material handling machine's driver's cab. It employs a dual parallel four-bar linkage lifting mechanism. The first-stage parallel four-bar linkage adjusts the driver's cab's near and far field of vision; the second-stage parallel four-bar linkage adjusts the driver's cab's high and low field of vision. By adjusting the movements of the first and second-stage parallel four-bar linkages, a motion envelope diagram of the driver's cab is formed in the spatial plane. Based on the varying heights, distances, and nearness of the material pile during loading and unloading operations, the driver's cab's field of vision is adjusted in real time to achieve the optimal viewing angle, thus satisfying the switching needs of different loading and unloading scenarios.

[0045] like Figure 1 , Figure 2 , Figures 5-7 As shown: the connecting support 6, the primary boom 5, the primary boom 8, and the triangular connecting frame 9 form a parallelogram CEHI, which constitutes a primary parallel four-bar linkage lifting mechanism. When the primary cylinder 7 is extended, the primary parallel four-bar linkage lifting mechanism CEHI rotates counterclockwise around the connecting support 6, causing the driver's cab 1 to move horizontally in the farthest direction, with a movement distance of L2. If the secondary cylinder 10 is then shortened until the secondary boom 3 reaches a horizontal position, the driver's cab 1 will move the farthest distance L1.

[0046] like Figure 1 , Figure 3 , Figure 5 , Figure 8 and Figure 9 As shown: The driver's cab lifting frame 2, the secondary boom 3, the secondary boom 4, and the triangular connecting frame 9 form a parallelogram ABHJ, which constitutes a secondary parallel four-bar linkage lifting mechanism. When the secondary cylinder 10 is shortened, the secondary parallel four-bar linkage lifting mechanism ABHJ rotates clockwise around the triangular connecting frame 9, causing the driver's cab 1 to move horizontally upwards by a distance of H2. If the primary cylinder 7 is then extended until the primary boom 5 or the primary boom 8 reaches a vertical position, the driver's cab 1 will move upwards by a distance of H1.

[0047] like Figure 4 As shown: By arbitrarily adjusting the extension and retraction of the first-stage hydraulic cylinder 7 and the second-stage hydraulic cylinder 10, the movement trajectory of the driver's cab 1 forms an envelope diagram in the spatial plane. Depending on the height, distance, and proximity of the material pile during loading and unloading operations, the driver's cab 1 can be moved to any point within the envelope diagram, thereby achieving the best field of view and meeting the needs of different loading and unloading scenarios.

[0048] Example 2

[0049] like Figure 10 As shown, a control system for the lifting mechanism of the operator's cab of a material handling machine includes a gear pump 11, a safety valve 12, an unloading directional valve 13, a three-position four-way directional valve 14, a hydraulic lock 15, an accumulator 16, a primary cylinder 7, a secondary cylinder 10, a hydraulic resistance 17, a check valve 18, a normally closed directional valve 19, an emergency switch 20, a two-position three-way directional valve 21, a hydraulic oil tank 23, and an electronic controller 22.

[0050] The hydraulic control system is connected as follows: the gear pump 11 outputs pressure oil, which is connected to the inlet of safety valve 12, unloading directional valve 13, three-position four-way directional valve 14, and two-position three-way directional valve 21 respectively; the working port of three-position four-way directional valve 14 is connected to the inlet of hydraulic lock 15, and the outlet of hydraulic lock 15 is connected to the large and small chambers of primary cylinder 7 respectively; the working port of two-position three-way directional valve 21 is connected to accumulator 16, small chamber of secondary cylinder 10 and hydraulic resistance 17 respectively via check valve 18, and the outlet of hydraulic resistance 17 is connected to the inlet of normally closed directional valve 19 and emergency switch 20 respectively; the outlets of safety valve 12, unloading directional valve 13, normally closed directional valve 19, and emergency switch 20, the return ports of three-position four-way directional valve 14 and two-position three-way directional valve 21, and the large chamber of secondary cylinder 10 converge into hydraulic oil tank 23; all solenoid valve signal terminals used for electrical control are connected to electronic controller 22.

[0051] Example 3

[0052] like Figure 10 As shown, a control method for the control system of the lifting mechanism of the operator's cab of a material handling machine is specifically as follows:

[0053] The electronic controller 22 is used to issue commands to turn the two signal terminals of the three-position four-way directional valve 14 on and off, thereby controlling the extension, retraction and stop of the first-stage hydraulic cylinder 7.

[0054] The electronic controller 22 is used to issue commands to turn the signal terminal of the two-position three-way directional valve 21 or the normally closed directional valve 19 on or off, thereby controlling the extension, retraction and stop of the secondary cylinder 10.

[0055] The electronic controller 22 is used to issue commands to control the unloading solenoid valve 13 to be on or off, so that the gear pump 11 is in an unloading state except when the first-stage cylinder 7 extends or retracts and the second-stage cylinder 10 retracts, which saves energy and is environmentally friendly.

[0056] Hydraulic lock 15 is used to lock the first-stage cylinder 7, and check valve 18 is used to lock the second-stage cylinder 10, ensuring that the mechanism does not sink in any state.

[0057] The small chamber of the secondary hydraulic cylinder 10 is connected to the accumulator 16, which is used to realize hydraulic shock absorption to eliminate pulsation when the lifting mechanism starts or stops, so as to ensure smooth operation of the mechanism without impact and improve ride comfort.

[0058] When the driver's cab 1 needs to be lowered, the secondary hydraulic cylinder 10 can extend autonomously by gravity alone, without the need for an additional power source.

[0059] When the vehicle loses power due to a malfunction, the emergency switch 20 installed in the driver's cab 1 can be activated to ensure that the driver's cab 1 can be lowered smoothly by its own weight, allowing the driver to evacuate quickly and safely.

[0060] The specific control method is as follows:

[0061] When the electronic controller 22 issues a command to energize and switch the unloading directional valve 13 and the three-position four-way directional valve 14 to the left or right position, the pressure oil output by the gear pump 11 flows into the large or small chamber of the first-stage cylinder 7 through the three-position four-way directional valve 14 and the hydraulic lock 15, thereby realizing the extension and retraction of the first-stage cylinder 7.

[0062] When the electronic controller 22 issues a command to energize and switch the unloading directional valve 13 and the two-position three-way directional valve 21, the pressure oil output by the gear pump 11 flows into the accumulator 16 and the secondary cylinder 10 through the two-position three-way directional valve 21 and the check valve 18, respectively, thereby shortening the secondary cylinder 10. At the moment of starting or stopping, the accumulator 16 plays a role in hydraulic damping to eliminate impact pulsation and ensure the smooth operation of the mechanism.

[0063] When the electronic controller 22 issues a command, only the normally closed directional valve 19 is energized and reversed. Due to the gravity of the driver's cab 1 being transmitted to the secondary cylinder 10, the oil in the small chamber of the secondary cylinder 10 is pressurized and flows back to the hydraulic oil tank 23 through the hydraulic resistance 17 and the normally closed directional valve 19. The oil in the hydraulic oil tank 23 with a certain back pressure is replenished to the large chamber of the secondary cylinder 10, realizing the extension of the secondary cylinder 10. No power source is involved in this process. The gear pump 11 is in an unloaded state through the unloading directional valve 13. Gravity is used to realize the autonomous extension of the secondary cylinder 10 to lower the driver's cab 1.

[0064] When the vehicle loses power due to a malfunction, the emergency switch 20 installed in the driver's cab 1 is activated to reverse the direction. The pressure oil in the small chamber of the secondary cylinder 10 flows back to the hydraulic oil tank 23 through the hydraulic resistor 17 and the emergency switch 20. Gravity is used to enable the secondary cylinder 10 to extend autonomously to lower the driver's cab 1. The driver's cab 1 can be lowered smoothly, ensuring that the driver can evacuate safely and quickly.

[0065] The hydraulic lock 15, which is connected to the large and small chambers of the first-stage cylinder 7, and the one-way valve 18, which is connected to the small chamber of the second-stage cylinder 10, play the role of locking the position of the cylinder. When the grabber is subjected to impact and vibration during operation, it ensures that the lifting mechanism does not sink in any state, thus improving the riding comfort.

[0066] The driver's cab lifting mechanism is hydraulically controlled. The movement of the first and second stage parallel four-bar lifting mechanisms is driven by hydraulic cylinders, which have a locking function to ensure that the mechanism does not sink in any state. The hydraulic lock 15, one-way valve 18, and accumulator 16 connected to the control system realize hydraulic shock absorption, ensuring smooth operation of the mechanism without impact and improving ride comfort. At the same time, the second stage parallel four-bar lifting mechanism adjusts the driver's cab descent by gravity autonomously, without the need for an external power source, which is energy-saving and environmentally friendly. In addition, the control system is equipped with an emergency switch for lowering the driver's cab. In emergency situations, such as when the vehicle loses power due to a malfunction, the emergency switch located in the driver's cab can ensure that the driver can evacuate safely and quickly. The entire system has low energy consumption, high reliability, and simple operation.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lifting device for the operator's cab of a material handling machine, characterized in that: Including the lifting mechanism and control system; The lifting mechanism includes a driver's cab, a driver's cab lifting frame, a secondary forearm, a secondary boom, a triangular connecting frame, a primary forearm, a primary boom, a connecting support, and a power unit. The driver's cab is fixed on the driver's cab frame. Hinge point A on the driver's cab frame is hinged to one end of the secondary boom, and the other end of the secondary boom is hinged to hinge point J of the triangular connecting frame. Hinge point B on the driver's cab frame is hinged to one end of the secondary boom, and the other end of the secondary boom is hinged to hinge point H of the triangular connecting frame. The driver's cab frame, secondary boom, secondary boom, and triangular connecting frame form a secondary parallel four-bar linkage lifting mechanism. The hinge point C on the connecting support is hinged to one end of the primary forearm, and the hinge point E on the connecting support is hinged to one end of the primary boom; the other end of the primary forearm is hinged to the hinge point H of the triangular connecting frame, and the other end of the primary boom is hinged to the hinge point I of the triangular connecting frame; the connecting support, the primary forearm, the primary boom, and the triangular connecting frame form a primary parallel four-bar linkage lifting mechanism. The power unit is used to drive the first-stage parallel four-bar linkage lifting mechanism and the second-stage parallel four-bar linkage lifting mechanism to achieve translation of the driver's cab; The control system includes a gear pump, safety valve, unloading directional valve, three-position four-way directional valve, hydraulic lock, accumulator, primary cylinder, secondary cylinder, hydraulic resistance, check valve, normally closed directional valve, emergency switch, two-position three-way directional valve, hydraulic oil tank and electronic controller. The gear pump outputs pressurized oil, which is connected to the inlets of the safety valve, unloading directional valve, three-position four-way directional valve, and two-position three-way directional valve, respectively. The working port of the three-position four-way directional valve is connected to the inlet of the hydraulic lock, and the outlet of the hydraulic lock is connected to the large and small chambers of the first-stage cylinder, respectively. The working port of the two-position three-way directional valve is connected to the accumulator, the small chamber of the second-stage cylinder, and the hydraulic resistance via a check valve, respectively. The outlet of the hydraulic resistance is connected to the inlet of the normally closed directional valve and the emergency switch, respectively. The outlets of the safety valve, unloading directional valve, normally closed directional valve, and emergency switch, the return ports of the three-position four-way directional valve and the two-position three-way directional valve, and the large chamber of the second-stage cylinder converge and flow into the hydraulic oil tank. The signal terminals of the solenoid valves used for electrical control are all connected to the electronic controller.

2. The lifting device for the operator's cab of the material handling machine according to claim 1, characterized in that: The power unit includes a secondary hydraulic cylinder and a primary hydraulic cylinder. The two ends of the secondary hydraulic cylinder are connected to the F hinge point of the secondary boom and the J hinge point of the triangular connecting frame, respectively. The two ends of the primary hydraulic cylinder are connected to the D hinge point of the connecting support and the G hinge point of the primary forearm, respectively.

3. The lifting device for the operator's cab of the material handling machine according to claim 2, characterized in that: The F hinge point of the secondary boom is located in the middle of the secondary boom; the G hinge point of the primary forearm is located on the side of the primary forearm near the triangular connecting frame; the D hinge point of the connecting support is located between the C hinge point and the E hinge point of the connecting support, and on the side near the E hinge point.

4. A control method for the lifting device of the operator's cab of a material handling machine as described in claim 1, characterized in that: The electronic controller is used to issue commands to turn the two signal terminals of the three-position four-way directional valve on and off, thereby controlling the extension, retraction and stop of the first-stage hydraulic cylinder. The electronic controller is used to issue commands to turn the two-position three-way reversing valve or the normally closed reversing signal terminal on and off, thereby controlling the extension, retraction and stop of the secondary cylinder; The electronic controller is used to issue commands to control the unloading solenoid valve to be powered on or off, so that the gear pump is in an unloading state except when the first-stage cylinder extends or retracts and the second-stage cylinder retracts. The hydraulic lock is used to lock the first-stage cylinder, and the check valve is used to lock the second-stage cylinder. The secondary cylinder's small chamber is connected to an accumulator, which is used to achieve hydraulic damping and eliminate pulsation when the lifting mechanism starts or stops.

5. The control method for the lifting device of the operator's cab of the grabber according to claim 4, characterized in that: When the driver's cab needs to be lowered, a command is issued via the electronic controller to energize and switch the normally closed directional valve. The weight of the driver's cab is transferred to the secondary hydraulic cylinder. The hydraulic fluid in the small chamber of the secondary hydraulic cylinder is pressurized and flows back to the oil tank through the hydraulic resistance and the normally closed directional valve. The hydraulic fluid in the hydraulic tank with a certain back pressure is replenished to the large chamber of the secondary hydraulic cylinder, realizing the extension of the secondary hydraulic cylinder. The gear pump is in an unloaded state through the unloading directional valve, and the secondary hydraulic cylinder extends autonomously by gravity to carry out the driver's cab lowering operation.

6. The control method for the lifting device of the operator's cab of the grabber according to claim 4, characterized in that: When the vehicle loses power due to a malfunction, the pressure oil in the small chamber of the secondary cylinder flows back to the oil tank through the hydraulic resistance and the emergency switch via the emergency switch. Gravity is then used to enable the secondary cylinder to extend autonomously to lower the driver's cab.

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