Small turning radius adjusting system for coal mine transport vehicle and control method

Abstract

The invention discloses a small turning radius adjusting system for a coal mine transport vehicle, and relates to the field of mining rubber wheel transport vehicles, a steering gear is arranged on a front vehicle of the transport vehicle, a driver manually rotates the steering gear, a steering oil cylinder is driven by the steering gear until the maximum steering angle is reached, and the steering gear cannot continue to rotate; a valve element in the pilot control valve is triggered to reverse, a single-linkage valve set is controlled to be communicated with a high-pressure oil source and the suspension oil cylinder, and the single-linkage valve set is communicated with the high-pressure oil source, rodless cavities of the left front oil cylinder and the right rear oil cylinder and rod cavities of the left rear oil cylinder and the right front oil cylinder. Or the high-pressure oil source is communicated with rod cavities of the right front oil cylinder and the left rear oil cylinder and rodless cavities of the left front oil cylinder and the right rear oil cylinder, the turning radius of the transport vehicle is reduced by changing extrusion force of tires on the ground, and the passing performance of the transport vehicle in a roadway is improved; meanwhile, the invention further provides a control method of the adjusting system, the control method can automatically control the turning radius of the transport vehicle, and the transport efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of mining rubber-tired transport vehicles, and in particular to a small turning radius adjustment system and control method for coal mine transport vehicles. Background Technology

[0002] Due to the limited space in underground coal mine roadways, transport vehicles are often designed with a narrow and long structure and a central articulated steering mechanism to facilitate passage through these roadways. For example, the "Small Turning Articulated Support Transport Vehicle" disclosed in patent application CN119659751A uses a front-to-rear articulated steering design. The front vehicle has two load-bearing wheels, and the rear vehicle has left and right swing beams on both sides, which are rotatably connected to the rear vehicle. Each end of the left and right swing beams has a load-bearing wheel. Based on the actual conditions of underground coal mine roadways and the structure of the aforementioned transport vehicle, a new small turning radius adjustment system and control method are developed to further reduce the turning radius of the transport vehicle and improve its performance in narrow roadways. Summary of the Invention

[0003] The purpose of this invention is to provide a small turning radius adjustment system and control method for coal mine transport vehicles, so as to solve the problems existing in the prior art, reduce the turning radius of the transport vehicle, and improve the passage performance of the transport vehicle in underground coal mine roadways.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a small turning radius adjustment system for a coal mine transport vehicle, including a high-pressure oil source, a steering gear, a steering cylinder, a pilot control valve group, a single valve group, and a suspension cylinder; The steering gear is used to drive the extension and retraction of the steering cylinder, and the output end of the high-pressure oil source is connected to the steering cylinder through the steering gear; The suspension cylinder is a double-acting cylinder. The single valve group is equipped with a hydraulic multi-way directional valve. The input end of the pilot control valve group is connected to the high-pressure oil source, and the output end of the pilot control valve group is connected to the control oil circuit in the hydraulic multi-way directional valve. The suspension cylinder includes a left front cylinder, a right front cylinder, a left rear cylinder, and a right rear cylinder. A single-pole valve assembly is used to connect the high-pressure oil source with the rodless chamber of the left front cylinder and the right rear cylinder, as well as the rod chamber of the left rear cylinder and the right front cylinder, or to connect the high-pressure oil source with the rod chamber of the right front cylinder and the left rear cylinder, as well as the rodless chamber of the left front cylinder and the right rear cylinder.

[0005] In one embodiment, the steering cylinder includes a left steering cylinder and a right steering cylinder, both of which are double-acting cylinders. The steering gear is provided with at least two oil outlets, one of which is connected to the rod chamber of the left steering cylinder and the rodless chamber of the right steering cylinder, and the other oil outlet is connected to the rodless chamber of the left steering cylinder and the rod chamber of the right steering cylinder.

[0006] In one embodiment, the pilot control valve assembly includes a left pilot control valve and a right pilot control valve.

[0007] In one embodiment, the hydraulic multi-way directional valve is a three-position five-way directional valve, and the high-pressure oil source includes an oil source and a hydraulic pump. The input end of the hydraulic pump is connected to the oil source, and the output end of the hydraulic pump is connected to the oil inlet of the three-position five-way directional valve. The oil outlets of the left and right pilot control valves are respectively connected to the two control oil circuits of the multi-way directional valve. The first working port on the multi-way directional valve corresponds to the control oil circuit connected to the left pilot control valve. The first working port is connected to the rodless chamber of the left front cylinder and the right rear cylinder, as well as the rod chamber of the left rear cylinder and the right front cylinder, through the left steering pipe. The second working port on the multi-way directional valve corresponds to the control oil circuit connected to the right pilot control valve. The second working port is connected to the rod chamber of the right front cylinder and the left rear cylinder, as well as the rodless chamber of the left front cylinder and the right rear cylinder, through the right steering pipe.

[0008] In one embodiment, a shuttle valve is provided between the left turn pipe and the right turn pipe. The two inlets of the shuttle valve are connected to the left turn pipe and the right turn pipe through pipes, and the outlet of the shuttle valve is connected to the overflow valve. The outlet of the overflow valve is connected to the oil source.

[0009] A control method for a small turning radius adjustment system for a coal mine transport vehicle includes the following steps: S1: When the steering gear is manually turned, the high-pressure oil drives the steering cylinder to move. When the steering gear is turned to the right, the piston rod of the left steering cylinder extends and the piston rod of the right steering cylinder retracts; when the steering gear is turned to the left, the piston rod of the right steering cylinder extends and the piston rod of the left steering cylinder retracts. The lead vehicle of the transport truck begins to turn until the steering gear can no longer be turned; S2: When the front vehicle of the transport vehicle turns, the inside of the front vehicle presses against the rear vehicle of the transport vehicle, and the pilot control valve group is activated. S3: The hydraulic oil in the left pilot control valve is squeezed into the hydraulic multi-way directional valve, driving the valve core in the hydraulic multi-way directional valve to move. The high-pressure oil source is connected to the suspension cylinder through the hydraulic multi-way directional valve. S4: When the transport vehicle turns right, the pressure between the right front tire and the left rear tire of the rear vehicle and the ground increases, while the pressure between the left front tire and the right rear tire and the ground decreases, causing the right turning center of the rear vehicle to move inward and reducing the right turning radius of the transport vehicle. When the transport vehicle turns left, the pressure between the left front tire and the right rear tire of the rear vehicle and the ground increases, while the pressure between the right front tire and the left rear tire and the ground decreases. This causes the left turning center of the rear vehicle to move inward, reducing the left turning radius of the transport vehicle.

[0010] In one embodiment, in step S2, the pilot control valve group includes a left pilot control valve and a right pilot control valve. The single valve group is provided with a hydraulic multi-way directional switch. The left pilot control valve and the right pilot control valve are respectively connected to different control oil circuits in the hydraulic multi-way directional switch. If the transport vehicle turns right, the right pilot control valve is activated. If the transport vehicle turns left, the left pilot control valve is activated.

[0011] In one embodiment, in step S3, the rear of the transport vehicle is rotatably equipped with a left swing beam and a right swing beam on both sides. The two ends of the left front oil cylinder and the left rear oil cylinder are respectively rotatably connected to the two ends of the left swing beam and the rear vehicle. The two ends of the right front oil cylinder and the right rear oil cylinder are respectively rotatably connected to the two ends of the right swing beam and the rear vehicle. The high-pressure oil source connects the rodless chamber of the left front cylinder and the right rear cylinder and the rod chamber of the right front cylinder and the left rear cylinder through a single valve group, causing the piston rods of the left front cylinder and the right rear cylinder to extend, while the piston rods of the right front cylinder and the left rear cylinder retract. If the right pilot control valve actuates, the hydraulic oil in the right pilot control valve is squeezed into the hydraulic multi-way directional switch, causing the valve core to move in the opposite direction. The high-pressure oil source connects the rodless chamber of the right front cylinder and the left rear cylinder, as well as the rod chamber of the left front cylinder and the right rear cylinder, through the single-joint valve group, causing the piston rods of the right front cylinder and the left rear cylinder to extend, while the piston rods of the left front cylinder and the right rear cylinder retract.

[0012] The present invention achieves the following technical effects compared to the prior art: The steering gear is mounted on the front of the transport vehicle. The driver manually turns the steering gear, directing high-pressure oil from the high-pressure oil source to the steering cylinders until the steering gear can no longer be turned. At this point, the pilot control valve activates, driving the valve core in the hydraulic multi-way directional valve to move. This valve connects the high-pressure oil source and the suspension cylinders via a single-pole valve assembly. The suspension cylinders include the left front cylinder, right front cylinder, left rear cylinder, and right rear cylinder. When the steering gear controls the transport vehicle to turn left, the single-pole valve assembly connects the high-pressure oil source to the rodless chambers of the left front and right rear cylinders, as well as the rod chambers of the left rear and right front cylinders, increasing the pressure between the left front and right rear tires of the rear vehicle and the ground. At the same time, it reduces the pressure between the left rear tire and the right front tire and the ground, causing the left turning center of the rear of the transport vehicle to move inward, thus reducing the overall left turning radius of the transport vehicle. When the steering gear controls the transport vehicle to turn right, the single-valve group connects the high-pressure oil source with the rod chambers of the right front cylinder and the left rear cylinder, as well as the rodless chambers of the left front cylinder and the right rear cylinder. This increases the pressure between the right front tire and the left rear tire of the rear of the transport vehicle and the ground, while reducing the pressure between the right rear tire and the left front tire and the ground. This causes the right turning center of the rear of the transport vehicle to move inward, reducing the overall right turning radius of the transport vehicle and improving the transport vehicle's passability in underground coal mine tunnels. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the small-turn articulated support transport vehicle in an embodiment of the present invention; Figure 2 This is a schematic diagram of the small turning radius adjustment system in an embodiment of the present invention; Among them, 1. Front vehicle; 2. Rear vehicle; 3. Left steering cylinder; 4. Right steering cylinder; 5. Left swing beam; 6. Right swing beam; 7. Left front tire; 8. Left rear tire; 9. Right front tire; 10. Right rear tire; 11. Left front cylinder; 12. Left rear cylinder; 13. Right front cylinder; 14. Right rear cylinder; 15. Steering gear; 16. Hydraulic pump; 17. Oil source; 18. Left pilot control valve; 19. Right pilot control valve; 20. Single valve assembly; 21. Hydraulic multi-way directional valve; 22. Shuttle valve; 23. Relief valve. Detailed Implementation

[0015] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The purpose of this invention is to provide a small turning radius adjustment system and control method for coal mine transport vehicles, so as to solve the problems existing in the prior art, reduce the turning radius of the transport vehicle, and improve the passage performance of the transport vehicle in underground coal mine roadways.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Please refer to Figures 1 to 2The small turning radius adjustment system of this invention includes a high-pressure oil source 17, a steering gear 15, a steering cylinder, a pilot control valve group, a single-valve group 20, and a suspension cylinder. The steering gear 15 is installed on the front vehicle 1 of the transport vehicle. The driver turns the steering gear by turning the steering wheel, controlling the high-pressure oil output from the high-pressure oil source 17 to enter the corresponding steering cylinder. The front vehicle 1 is turned by the extension and retraction of the steering cylinder. Since the turning angle of the front vehicle 1 is limited, after the steering wheel is turned to the limit position, the turning radius adjustment system between the front vehicle 1 and the rear vehicle 2 is reduced. The pilot control valve group starts to operate. The input end of the pilot control valve group is connected to the high-pressure oil source 17. The high-pressure oil source 17 provides high-pressure oil to the pilot control valve group. The output end of the pilot control valve group is connected to the control oil circuit in the hydraulic multi-way directional valve 21 in the single valve group 20. The pilot control valve group drives the valve core in the hydraulic multi-way directional valve 21 to move through the high-pressure oil according to the steering situation of the front vehicle 1. The hydraulic multi-way directional valve 21 connects the suspension cylinder and the high-pressure oil source 17. The suspension cylinder is a double-acting cylinder. The suspension cylinders include a left front cylinder 11, a right front cylinder 13, a left rear cylinder 12, and a right rear cylinder 14. When the pilot control valve group drives the valve core in the hydraulic multi-way directional valve 21 to move through the high pressure oil, the single valve group 20 connects the high pressure oil source 17 with the rodless chambers of the left front cylinder 11 and the right rear cylinder 14, as well as the rod chambers of the left rear cylinder 12 and the right front cylinder 13. This increases the pressure between the left front tire 7 and the right rear tire 10 in the rear vehicle 2 and the ground, while the pressure between the left rear tire 8 and the right front tire 9 and the ground decreases. This causes the steering center of the transport vehicle to move closer to the direction of the transport vehicle when it turns left, thereby reducing the turning radius of the transport vehicle when it turns left. Similarly, the single-valve assembly 20 connects the high-pressure oil source 17 to the rod chambers of the right front cylinder 13 and the left rear cylinder 12, as well as the rodless chambers of the left front cylinder 11 and the right rear cylinder 14, thereby reducing the compressive force between the left front tire 7 and the right rear tire 10 in the rear vehicle 2 and the ground, while increasing the compressive force between the corresponding left rear tire 8 and the right front tire 9 and the ground. This causes the steering center of the transport vehicle to move closer to the direction of the transport vehicle when it turns right, thereby reducing the turning radius of the transport vehicle when it turns right.

[0019] The steering cylinder includes a left steering cylinder 3 and a right steering cylinder 4. The left steering cylinder 3 and the right steering cylinder 4 are double-acting cylinders. The steering gear 15 is provided with at least two oil outlets. One oil outlet is connected to the rod chamber of the left steering cylinder 3 and the rodless chamber of the right steering cylinder 4. The other oil outlet is connected to the rodless chamber of the left steering cylinder 3 and the rod chamber of the right steering cylinder 4. When the driver turns the steering wheel to the left, the high-pressure oil source 17 introduces high-pressure oil through the steering gear 15 into the rodless chamber of the right steering cylinder 4 and the rod chamber of the left steering cylinder 3, causing the left steering cylinder 3 to contract and the right steering cylinder 4 to extend, so that the transport vehicle turns with the minimum left turning radius. Similarly, when the driver turns the steering wheel to the right, the high-pressure oil source 17 supplies high-pressure oil through the steering gear 15 to the rod chamber of the right steering cylinder 4 and the rodless chamber of the left steering cylinder 3, causing the right steering cylinder 4 to contract and the left steering cylinder 3 to extend, so that the transport vehicle turns with the minimum right turning radius.

[0020] The pilot control valve assembly is located at the front end of the rear vehicle 2. The pilot control valve assembly includes a left pilot control valve 18 and a right pilot control valve 19. The left pilot control valve 18 is located on the left side of the left steering cylinder 3, while the right pilot control valve 19 is located on the right side of the right steering cylinder 4. When the driver turns the steering wheel to its limit position, the front vehicle 1 begins to turn with the minimum turning radius. At this time, the front vehicle 1 compresses the pilot control valve assembly located on the rear vehicle 2, causing the pilot control valve assembly to start operating. That is, when the front vehicle 1 turns left, it compresses the left pilot control valve 18, and when the front vehicle 1 turns right, it compresses the right pilot control valve 19. The pilot control valve assembly controls the single valve assembly 20 to connect the high-pressure oil source 17 to different suspension cylinders, thereby changing the compressive force between different tires on the rear vehicle 2 and the ground.

[0021] Preferably, the hydraulic multi-way directional valve 21 is a three-position five-way directional valve, and the high-pressure oil source 17 includes an oil source 17 and a hydraulic pump 16. The input end of the hydraulic pump 16 is connected to the oil source 17, and the output end of the hydraulic pump 16 is connected to the oil inlet of the three-position five-way directional valve. The oil outlets of the left pilot control valve 18 and the right pilot control valve 19 are respectively connected to the two control oil circuits of the multi-way directional valve. The first working port on the multi-way directional valve corresponds to the control oil circuit connected to the left pilot control valve 18. The first working port is connected to the rodless chamber of the left front cylinder 11 and the right rear cylinder 14, and the rod chamber of the left rear cylinder 12 and the right front cylinder 13 through the left steering pipe. The second working port on the multi-way directional valve corresponds to the control oil circuit connected to the right pilot control valve 19. The second working port is connected to the rod chamber of the right front cylinder 13 and the left rear cylinder 12, and the rodless chamber of the left front cylinder 11 and the right rear cylinder 14 through the right steering pipe.

[0022] A shuttle valve 22 is installed between the left and right turn pipes. The shuttle valve 22 is connected in parallel with the left and right turn pipes, and the control port is connected to the overflow valve 23 to form a closed-loop pressure regulation system. When the internal pressure of the left and right turn pipes reaches the threshold, the overflow valve 23 releases the pressure inside the left and right turn pipes. The maximum pressure between the tire and the ground can be limited by adjusting the overflow pressure to avoid overload of the internal pressure of the left and right turn pipes. The high-pressure oil discharged from the outlet of the overflow valve 23 flows back to the oil source 17. Preferably, the overflow valve 23 can be a manual overflow valve. After the rear vehicle 2 is loaded, the pressure threshold of the overflow valve 23 can be manually adjusted according to the actual load of the rear vehicle 2. The overflow valve 23 can also be an electronically controlled overflow valve, which can automatically adjust the overflow pressure according to the real-time load of the rear vehicle 2. That is, during the loading process, the actual load of the rear vehicle is calculated based on the load of the four sets of suspension cylinders, and the pressure of the overflow valve 23 is dynamically adjusted according to the actual load to achieve the ideal turning radius adjustment effect.

[0023] A control method for a small turning radius adjustment system for a coal mine transport vehicle includes the following steps: S1: By manually turning the steering wheel, the steering gear 15 is turned, and the high-pressure oil drives the steering cylinder to move. When the steering gear 15 turns to the right, the piston rod of the left steering cylinder 3 extends and the piston rod of the right steering cylinder 4 retracts; when the steering gear 15 turns to the left, the piston rod of the right steering cylinder 4 extends and the piston rod of the left steering cylinder 3 retracts; the front vehicle 1 of the transport vehicle begins to turn until the steering gear 15 can no longer turn. At this time, the transport vehicle turns with the minimum turning radius before the adjustment system intervenes. S2: When the front vehicle 1 of the transport vehicle turns, the inside of the front vehicle 1 presses against the front end of the rear vehicle 2 of the transport vehicle, and the pilot control valve group is activated. Preferably, in step S2, when the front vehicle 1 turns to its limit position, the inner side of the front vehicle 1 presses against the front end of the rear vehicle 2, and the pilot control valve group is located at the front end of the rear vehicle 2. The pilot control valve group starts to operate after being pressed by the front vehicle 1. The pilot control valve group includes a left pilot control valve 18 and a right pilot control valve 19. The single valve group 20 is equipped with a hydraulic multi-way directional switch. The left pilot control valve 18 and the right pilot control valve 19 are respectively connected to different control oil circuits in the hydraulic multi-way directional switch. If the transport vehicle turns right, the right pilot control valve 19 operates. If the transport vehicle turns left, the left pilot control valve 18 operates. S3: The hydraulic oil in the pilot control valve group is squeezed into the hydraulic multi-way directional valve 21, driving the valve core in the hydraulic multi-way directional valve 21 to move. The high-pressure oil source 17 is connected to the suspension cylinder through the hydraulic multi-way directional valve 21. Preferably, in step S3, the rear vehicle 2 of the transport vehicle is rotatably equipped with a left swing beam 5 and a right swing beam 6 on both sides. The two ends of the left front cylinder 11 and the left rear cylinder 12 are rotatably connected to the two ends of the left swing beam 5 and the rear vehicle 2, respectively. The two ends of the right front cylinder 13 and the right rear cylinder 14 are rotatably connected to the two ends of the right swing beam 6 and the rear vehicle 2, respectively. The high-pressure oil source 17 connects the rodless chambers of the left front cylinder 11 and the right rear cylinder 14, as well as the rod chambers of the right front cylinder 13 and the left rear cylinder 12, through the single valve group 20, so that the piston rods of the left front cylinder 11 and the right rear cylinder 14 extend, while the piston rods of the right front cylinder 13 and the left rear cylinder 12 retract. If the right pilot control valve 19 actuates, the hydraulic oil in the right pilot control valve 19 is squeezed into the hydraulic multi-way directional switch, causing the valve core to move in the opposite direction. The high-pressure oil source 17 connects the rodless chambers of the right front cylinder 13 and the left rear cylinder 12, as well as the rod chambers of the left front cylinder 11 and the right rear cylinder 14, through the single-port valve assembly 20, causing the piston rods of the right front cylinder 13 and the left rear cylinder 12 to extend, while the piston rods of the left front cylinder 11 and the right rear cylinder 14 retract. S4: After adjustments in steps S1 to S3, such as Figure 1 As shown, when the transport vehicle turns right, the pressure between the right front tire 9 and the left rear tire 8 of the rear vehicle 2 and the ground increases, while the pressure between the left front tire 7 and the right rear tire 10 and the ground decreases, causing the right turning center of the rear vehicle 2 to move inward and reducing the right turning radius of the transport vehicle. Similarly, when the transport vehicle turns left, the pressure between the left front tire 7 and the right rear tire 10 of the rear vehicle 2 and the ground increases, while the pressure between the right front tire 9 and the left rear tire 8 and the ground decreases, causing the left turning center of the rear vehicle 2 to move inward and reducing the left turning radius of the transport vehicle.

[0024] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0025] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0026] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A small turning radius adjustment system for a coal mine transport vehicle, characterized in that, Includes a high-pressure oil source (17), a steering gear (15), a steering cylinder, a pilot control valve assembly, a single valve assembly (20), and a suspension cylinder; The steering gear (15) is used to drive the steering cylinder to extend and retract, and the output end of the high-pressure oil source (17) is connected to the steering cylinder through the steering gear (15); The suspension cylinder is a double-acting cylinder. The single valve group (20) is equipped with a hydraulic multi-way directional valve (21). The input end of the pilot control valve group is connected to the high-pressure oil source (17). The output end of the pilot control valve group is connected to the control oil circuit in the hydraulic multi-way directional valve (21). The suspension cylinder includes a left front cylinder (11), a right front cylinder (13), a left rear cylinder (12), and a right rear cylinder (14). The single-joint valve group (20) is used to connect the high-pressure oil source (17) with the rodless chamber of the left front cylinder (11) and the right rear cylinder (14) and the rod chamber of the left rear cylinder (12) and the right front cylinder (13), or, to connect the high-pressure oil source (17) with the rod chamber of the right front cylinder (13) and the left rear cylinder (12) and the rodless chamber of the left front cylinder (11) and the right rear cylinder (14).

2. The small turning radius adjustment system for coal mine transport vehicles according to claim 1, characterized in that, The steering cylinder includes a left steering cylinder (3) and a right steering cylinder (4). The left steering cylinder (3) and the right steering cylinder (4) are double-acting cylinders. The steering gear (15) is provided with at least two oil outlets. One of the oil outlets is connected to the rod chamber of the left steering cylinder (3) and the rodless chamber of the right steering cylinder (4). The other oil outlet is connected to the rodless chamber of the left steering cylinder (3) and the rod chamber of the right steering cylinder (4).

3. The small turning radius adjustment system for coal mine transport vehicles according to claim 2, characterized in that, The pilot control valve group includes a left pilot control valve (18) and a right pilot control valve (19).

4. The small turning radius adjustment system for coal mine transport vehicles according to claim 3, characterized in that, The hydraulic multi-way directional valve (21) is a three-position five-way directional valve. The high-pressure oil source (17) includes an oil source (17) and a hydraulic pump (16). The input end of the hydraulic pump (16) is connected to the oil source (17), and the output end of the hydraulic pump (16) is connected to the oil inlet of the three-position five-way directional valve. The oil outlets of the left pilot control valve (18) and the right pilot control valve (19) are respectively connected to the two control oil circuits of the multi-way directional valve. The first working port on the multi-way directional valve corresponds to the control oil circuit connected to the left pilot control valve (18). The first working port is connected to the rodless chamber of the left front cylinder (11) and the right rear cylinder (14) and the rod chamber of the left rear cylinder (12) and the right front cylinder (13) through the left steering pipe. The second working port on the multi-way directional valve corresponds to the control oil circuit connected to the right pilot control valve (19). The second working port is connected to the rod chamber of the right front cylinder (13) and the left rear cylinder (12) and the rodless chamber of the left front cylinder (11) and the right rear cylinder (14) through the right steering pipe.

5. The small turning radius adjustment system for coal mine transport vehicles according to claim 4, characterized in that, A shuttle valve (22) is provided between the left turn pipe and the right turn pipe. The two inlets of the shuttle valve (22) are connected to the left turn pipe and the right turn pipe through pipes. The outlet of the shuttle valve (22) is connected to the overflow valve (23). The outlet of the overflow valve (23) is connected to the oil source (17).

6. A control method for a small turning radius adjustment system for coal mine transport vehicles as described in claim 5, characterized in that, Includes the following steps: S1: Manually rotate the steering gear (15), and the high-pressure oil drives the steering cylinder to move. When the steering gear (15) turns to the right, the piston rod of the left steering cylinder (3) extends and the piston rod of the right steering cylinder (4) retracts. When the steering gear (15) turns to the left, the piston rod of the right steering cylinder (4) extends and the piston rod of the left steering cylinder (3) retracts. The lead vehicle (1) of the transport vehicle begins to turn until the steering gear (15) can no longer turn; S2: After the front vehicle (1) of the transport vehicle turns to the maximum steering angle, the inner side of the front vehicle (1) of the transport vehicle squeezes the rear vehicle (2) of the transport vehicle, and the pilot control valve group is activated. S3: The hydraulic oil in the left pilot control valve (18) is squeezed into the hydraulic multi-way directional valve (21), driving the valve core in the hydraulic multi-way directional valve (21) to move. The high-pressure oil source (17) is connected to the suspension cylinder through the hydraulic multi-way directional valve (21). S4: When the transport vehicle turns right, the pressure between the right front tire (9) and the left rear tire (8) of the rear vehicle (2) of the transport vehicle and the ground increases, and the pressure between the left front tire (7) and the right rear tire (10) and the ground decreases, so that the right turning center of the rear vehicle (2) of the transport vehicle moves inward and the right turning radius of the transport vehicle is reduced. When the transport vehicle turns left, the pressure between the left front tire (7) and the right rear tire (10) of the rear vehicle (2) and the ground increases, while the pressure between the right front tire (9) and the left rear tire (8) and the ground decreases, causing the left turning center of the rear vehicle (2) of the transport vehicle to move inward and reducing the left turning radius of the transport vehicle.

7. The control method for the small turning radius adjustment system of a coal mine transport vehicle according to claim 6, characterized in that, In step S2, the pilot control valve group includes the left pilot control valve (18) and the right pilot control valve (19). The single valve group (20) is equipped with a hydraulic multi-way directional switch. The left pilot control valve (18) and the right pilot control valve (19) are respectively connected to different control oil circuits in the hydraulic multi-way directional switch. If the transport vehicle turns right, the right pilot control valve (19) will be activated. If the transport vehicle turns left, the left pilot control valve (18) will be activated.

8. The control method for the small turning radius adjustment system of a coal mine transport vehicle according to claim 6, characterized in that, In step S3, the rear vehicle (2) of the transport vehicle is rotatably equipped with a left swing beam (5) and a right swing beam (6) on both sides. The two ends of the left front cylinder (11) and the left rear cylinder (12) are rotatably connected to the two ends of the left swing beam (5) and the rear vehicle (2), respectively. The two ends of the right front cylinder (13) and the right rear cylinder (14) are rotatably connected to the two ends of the right swing beam (6) and the rear vehicle (2), respectively. The high-pressure oil source (17) connects the rodless chamber of the left front cylinder (11) and the right rear cylinder (14) and the rod chamber of the right front cylinder (13) and the left rear cylinder (12) through the single valve group (20), causing the piston rods of the left front cylinder (11) and the right rear cylinder (14) to extend, while causing the piston rods of the right front cylinder (13) and the left rear cylinder (12) to retract. If the right pilot control valve (19) is activated, the hydraulic oil in the right pilot control valve (19) is squeezed into the hydraulic multi-way directional switch, causing the valve core to move in the opposite direction. The high-pressure oil source (17) connects the rodless chamber of the right front cylinder (13) and the left rear cylinder (12) and the rod chamber of the left front cylinder (11) and the right rear cylinder (14) through the single valve group (20), causing the piston rods of the right front cylinder (13) and the left rear cylinder (12) to extend, while causing the piston rods of the left front cylinder (11) and the right rear cylinder (14) to retract.

Images