Gear shifting system and method of wheel excavator

Abstract

The gear shifting system comprises a transfer connector, a hydraulic motor A, a gear shifting control valve, a reduction gearbox and a hydraulic motor B. The transfer connector is connected with the gear shifting control valve, the gear shifting control valve is connected with the hydraulic motor A and the hydraulic motor B, and the hydraulic motor A and the hydraulic motor B are connected with the reduction gearbox. And the reduction gearbox is arranged on the frame. According to the system, gear shifting operation of the vehicle at any vehicle speed can be achieved, the hydraulic motor does not have the overspeed phenomenon in the gear shifting process, the comfort of a driver and the reliability of the hydraulic motor are improved, high-speed running can be continuously conducted, the working efficiency is improved, the hydraulic motor can be effectively protected through the balance valve, and the service life of the vehicle is prolonged. And the phenomenon of slope sliding can be prevented, and the safety of the whole vehicle is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle shifting systems, and in particular relates to a shifting system and method for a wheeled excavator. Background Art

[0002] The traditional wheeled excavator travel system mainly has two modes: shifting by stopping and shifting by controlling the vehicle speed. When shifting without stopping, the hydraulic motor is prone to overspeed, which affects the comfort and reliability of the operator. Therefore, a control system that can shift gears without stopping or controlling the vehicle speed is needed to improve the practical performance of the vehicle.

[0003] The patent document with the announcement number CN111962600A discloses a cruise control device for a wheeled excavator and a control method thereof. A gearbox is arranged inside the excavator, and the output end of the gearbox is connected to the front axle and the rear axle respectively. The input end of the gearbox is connected to a travel motor through a transmission shaft, and the travel motor is connected to a travel valve core through a hydraulic hose. The travel valve core is connected to an integrated solenoid valve through a hydraulic hose, and the integrated solenoid valve is connected to a shift solenoid valve, and the shift solenoid valve is connected to a shift handle. The integrated solenoid valve includes a forward valve, a reverse valve, and a neutral valve. The integrated solenoid valve is connected to an electromagnetic proportional valve through a hydraulic hose. The invention controls the engine speed by using a hydraulic valve, and controls the opening state of the electromagnetic proportional valve to remain constant through a switch and a controller, thereby realizing the electronically controlled hydraulic valve to adjust the speed, and the whole vehicle can cruise at a constant speed, and ensure that the power increase offsets the additional power consumption on the bumpy road. However, the patent does not have a specific valve structure and a valve adjustment method.

[0004] The patent document with the announcement number CN202914704U discloses a hydraulic three-position shift mechanism. In order to solve the shortcomings of the existing connecting rod shift mechanism, such as complex structure, low transmission efficiency and easy wear, a hydraulic three-position shift mechanism is provided. The mechanism includes a cylindrical outer shell, a cylindrical sliding block is slidably arranged in the outer shell, and a return spring is arranged at both ends of the sliding block and the two ends of the outer shell. A first oil chamber for pushing the sliding block to move to the right and a second oil chamber for pushing the sliding block to move to the left are arranged between the sliding block and the outer shell. The first and second oil chambers are respectively connected to the PA oil port and the PB oil port arranged on the outer shell; one end of the sliding block is a connecting part, and one end of the outer shell is provided with a window for the connecting part to extend. This mechanism adopts hydraulic drive, spring return and mechanical limit, and is used in conjunction with hydraulic or / and electronic control devices. It is directly installed in the speed change valve without adjustment. However, this patent has only two oil chambers, and the number of hydraulic motors connected and controlled is limited. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a gear shifting system and method for a wheeled excavator.

[0006] The present invention is achieved through the following technical solutions.

[0007] The shifting system of a wheeled excavator provided by the present invention comprises a transfer joint, a hydraulic motor A, a shifting control valve, a reduction box, and a hydraulic motor B. The transfer joint is connected to the shifting control valve, and the shifting control valve is respectively connected to the hydraulic motor A and the hydraulic motor B. The hydraulic motor A and the hydraulic motor B are respectively connected to the reduction box, and the reduction box is arranged on a vehicle frame.

[0008] Preferably, a balancing valve is provided on the hydraulic motor A, two or more hydraulic motors A are provided, and the liquid outlet and the liquid inlet of the hydraulic motor A are connected to the shift control valve through a single hydraulic motor oil pipe A respectively.

[0009] Preferably, two or more hydraulic motors B are provided, and the fluid outlet and fluid inlet of the hydraulic motor B are connected to the shift control valve through a single hydraulic motor oil pipe B respectively.

[0010] Preferably, a switching valve oil pipe is provided on the shift control valve, one end of the switching valve oil pipe is connected to the shift control valve, and the other end of the switching valve oil pipe is connected to the transfer joint, and the liquid outlet and liquid inlet of the transfer joint are respectively connected to the transfer joint through a single switching valve oil pipe.

[0011] Preferably, an end cover, a valve stem A and a valve stem B are provided on the shift control valve, and an oil chamber A, an oil chamber B, an oil chamber C and an oil chamber D are provided in the shift control valve. The valve stem A penetrates the oil chamber D for sliding connection, and the valve stem B penetrates the oil chamber C, the oil chamber B and the oil chamber A for sliding connection from left to right in sequence. The end covers are respectively provided on one side of the valve stem A and the valve stem B. The oil chamber A is connected to the oil inlet of the hydraulic motor A, the oil chamber B is connected to the oil outlet of the hydraulic motor A, the oil chamber C is connected to the oil outlet of the hydraulic motor B, and the oil chamber D is connected to the oil inlet of the hydraulic motor B.

[0012] Preferably, an opening A is provided on one side of the oil chamber A, and an opening B is provided on the other side of the oil chamber A. The oil chamber A is connected with the oil channel A through the opening B, and the oil chamber A is connected with the oil chamber D through the oil channel A. One side of the oil chamber B is connected with the oil channel A through the opening C, and the other side of the oil chamber B is connected with the oil chamber C through the opening D. An opening E is provided on the other side of the oil chamber C, an opening F is provided on one side of the oil chamber D, and the other side of the oil chamber D is connected to one side of the cavity A through the opening G. The other side of the cavity A is connected to one side of the cavity B through the opening H, and the other side of the cavity B is provided with an opening I.

[0013] Preferably, seal A, seal B and seal C are provided on the valve stem A, one end of the valve stem A is connected to the guide sleeve, and the other end of the valve stem A is connected to the control oil block A, an oil channel B is provided inside the control oil block A, and the oil channel B of the control oil block A is connected by a transfer joint.

[0014] Preferably, seals D, E, F, G and H are provided on the valve stem B, one end of the valve stem B is connected to the guide sleeve, the other end of the valve stem B is connected to the control oil block B, and the oil channel C of the control oil block B is connected to the transfer joint.

[0015] Preferably, an elastic member is disposed inside the end cover.

[0016] The shifting method of the gear shifting system of a wheeled excavator comprises the following steps:

[0017] S1: Hydraulic oil enters the shift control valve through oil chamber A. In low gear, the vehicle servo control system controls the hydraulic oil to push valve stem A and valve stem B to move rightward through control oil block A and control oil block B respectively, compressing the elastic member so that oil chamber A and oil chamber D are in a connected state, and oil chamber B and oil chamber C are in a connected state. The hydraulic oil drives hydraulic motor A and hydraulic motor B to rotate, and returns oil through oil chamber B and oil chamber C at the same time. The whole vehicle is driven by hydraulic motor A and hydraulic motor B at the same time.

[0018] S2: When shifting to high gear, the vehicle servo control system cuts off the oil circuit, the compressed elastic member resumes its extension and pushes valve stem A and valve stem B to move to the left, so that oil chamber A is in a closed state, and the hydraulic oil enters hydraulic motor A through oil chamber A. The entire vehicle is driven by hydraulic motor A. At this time, hydraulic motor A is in a high-speed rotation state. In this state, oil chamber B and oil chamber D are connected, and the return oil of hydraulic motor A enters hydraulic motor B through oil chamber D to flush and lubricate hydraulic motor B.

[0019] The beneficial effects of the present invention are:

[0020] The system of the present invention can realize the gear shifting operation of the vehicle at any vehicle speed. The hydraulic motor will not overspeed during the gear shifting process, which improves the comfort of the driver and the reliability of the hydraulic motor. It can continuously travel at high speed and improve work efficiency. The balance valve can effectively protect the hydraulic motor, prevent the occurrence of slope sliding, and improve the safety of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the shift control valve of the present invention;

[0023] In the figure: 1-transfer joint, 2-hydraulic motor A, 3-balance valve, 4-hydraulic motor oil pipe A, 5-shift control valve, 51-end cover, 52-valve stem A, 521-seal A, 522-seal B, 523-seal C, 53-valve stem B, 531-seal D, 532-seal E, 533-seal F, 534-seal G, 535-seal H, 54-oil chamber A, 541-opening A, 542-opening B, 55-oil chamber B, 551-opening C, 552 -opening D, 56-oil chamber C, 561-opening E, 57-oil chamber D, 571-opening F, 572-opening G, 58-guide sleeve, 59-control oil block A, 591-oil channel B, 510-control oil block B, 5101-oil channel C, 511-oil channel A, 512-cavity A, 5121-opening H, 513-cavity B, 5131-opening I, 514-elastic part, 6-reduction gearbox, 7-hydraulic motor oil pipe B, 8-hydraulic motor B, 9-switching valve oil pipe, 101-frame. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0025] Example:

[0026] like Figure 1-2 As shown, the shifting system of the wheeled excavator includes a transfer joint 1, a hydraulic motor A2, a shift control valve 5, a reduction box 6, and a hydraulic motor B8. The transfer joint 1 is connected to the shift control valve 5, and the shift control valve 5 is respectively connected to the hydraulic motor A2 and the hydraulic motor B8. The hydraulic motor A2 and the hydraulic motor B8 are respectively connected to the reduction box 6, and the reduction box 6 is arranged on the frame 101.

[0027] The hydraulic motor A2 is provided with a balancing valve 3. Two or more hydraulic motors A2 are provided. In this embodiment, two hydraulic motors A2 are provided. The liquid outlet and the liquid inlet of the hydraulic motor A2 are respectively connected to the shift control valve 5 through a single hydraulic motor oil pipe A4.

[0028] The hydraulic motors B8 are provided with two or more. In the present embodiment, two hydraulic motors B8 are provided. The fluid outlet and the fluid inlet of the hydraulic motor B8 are respectively connected to the shift control valve 5 through a single hydraulic motor oil pipe B7.

[0029] A switching valve oil pipe 9 is provided on the shift control valve 5, one end of the switching valve oil pipe 9 is connected to the shift control valve 5, and the other end of the switching valve oil pipe 9 is connected to the transfer joint 1, and the liquid outlet and liquid inlet of the transfer joint 1 are respectively connected to the transfer joint 1 through a single switching valve oil pipe 9.

[0030] The shift control valve 5 is provided with an end cover 51, a valve stem A52, and a valve stem B53. The shift control valve 5 is provided with an oil chamber A54, an oil chamber B55, an oil chamber C56, and an oil chamber D57. The valve stem A52 penetrates the oil chamber D57 for sliding connection. The valve stem B53 penetrates the oil chamber C56, the oil chamber B55, and the oil chamber A54 for sliding connection from left to right in sequence. The end cover 51 is respectively provided on one side of the valve stem A52 and the valve stem B53. The oil chamber A54 is connected to the oil inlet of the hydraulic motor A2. The oil chamber B55 is connected to the oil outlet of the hydraulic motor A2. The oil chamber C56 is connected to the oil outlet of the hydraulic motor B8. The oil chamber D57 is connected to the oil inlet of the hydraulic motor B8.

[0031] An opening A541 is provided on one side of the oil chamber A54, and the end cover 51 on one side of the oil chamber A54 is connected through the opening A541. An opening B542 is provided on the other side of the oil chamber A54, and the oil chamber A54 is connected with the oil passage A511 through the opening B542, and the oil chamber A54 is connected with the oil chamber D57 through the oil passage A511. One side of the oil chamber B55 is connected with the oil passage A511 through the opening C551, and the other side of the oil chamber B55 is connected with the oil chamber C56 through the opening D552. An opening E561 is provided on the other side of the oil chamber C56. An opening F571 is provided on one side of the oil chamber D57, and the other side of the oil chamber D57 is connected with one side of the cavity A512 through the opening G572. The other side of the cavity A512 is connected with one side of the cavity B513 through the opening H5121. An opening I5131 is provided on the other side of the cavity B513, and the end cover 51 on one side of the cavity B513 is connected through the opening I5131.

[0032] The valve stem A52 is provided with a seal A521, a seal B522 and a seal C523. One end of the valve stem A52 is connected to the guide sleeve 58, and the other end of the valve stem A52 is connected to the control oil block A59. The control oil block A59 is provided with an oil passage B591 inside. The oil passage B591 of the control oil block A59 is connected to the transfer joint 1 through the switching valve oil pipe 9. The seal A521 is used to block the opening F571 for sealing, the seal B522 is used to block the opening G572 for sealing, and the seal C523 is used to block the opening H5121 for sealing.

[0033] The valve stem B53 is provided with a seal D531, a seal E532, a seal F533, a seal G534 and a seal H535. One end of the valve stem B53 is connected to the guide sleeve 58, and the other end of the valve stem B53 is connected to the control oil block B510. The oil passage C5101 of the control oil block B510 is connected to the transfer joint 1 through the switching valve oil pipe 9. The seal D531 is used to block the opening E561 for sealing, the seal E532 is used to block the opening D552 for sealing, the seal F533 is used to block the opening C551 for sealing, the seal G534 is used to block the opening B542 for sealing, and the seal H535 is used to block the opening A541 for sealing.

[0034] An elastic member 514 is disposed in the end cover 51 , one end of the elastic member 514 is connected to the inner wall of the end cover 51 , and the other end of the elastic member 514 is connected to the valve stem A52 or the valve stem B53 through a guide sleeve 58 .

[0035] The shifting method of the gear shifting system of a wheeled excavator comprises the following steps:

[0036] S1: Hydraulic oil enters the shift control valve 5 through the oil chamber A54. In the off-road low-speed gear, the vehicle servo control system controls the hydraulic oil to push the valve stem A52 and the valve stem B53 to move to the right through the control oil block A59 and the control oil block B510 respectively, compressing the elastic member 514, so that the oil chamber A54 and the oil chamber D57 are in a connected state, and the oil chamber B55 and the oil chamber C56 are in a connected state. The hydraulic oil drives the hydraulic motor A2 and the hydraulic motor B8 to rotate, and returns the oil through the oil chamber B55 and the oil chamber C56 at the same time. The whole vehicle is driven by two hydraulic motors A2 and two hydraulic motors B8 at the same time, meeting the off-road driving requirements.

[0037] S2: When shifting to high gear, the vehicle servo control system cuts off the oil circuit, and the control oil block A59 and the control oil block B510 have no thrust on the valve stem A52 and the valve stem B53. The compressed elastic member 514 resumes its extension and pushes the valve stem A52 and the valve stem B53 to move to the left, so that the oil chamber A54 is in a closed state, and the hydraulic oil enters the hydraulic motor A2 through the oil chamber A54. The whole vehicle is driven by two hydraulic motors A2. At this time, the hydraulic motor A2 is in a high-speed rotation state, meeting the high-speed driving requirements. In this state, the oil chamber B55 and the oil chamber D57 are connected, and the return oil of the hydraulic motor A2 enters the hydraulic motor B8 through the oil chamber D57, flushing and lubricating the hydraulic motor B8, ensuring the high-speed rotation requirements of the hydraulic motor B8 and improving the reliability of the motor.

[0038] The system of the present invention is suitable for a wheeled excavator. The hydraulic oil provided by the hydraulic pump on the wheeled excavator is transmitted from the upper platform of the vehicle to the chassis of the wheeled excavator through the transfer joint 1. The hydraulic oil on the transfer joint 1 is distributed to the hydraulic motor B8 and the hydraulic motor A2 installed on the reduction box 6 through the hydraulic motor oil pipe B7 and the hydraulic motor oil pipe A4 through the shift control valve 5, thereby driving the gears in the reduction box 6 to rotate and providing driving force for the whole vehicle.

[0039] When off-road driving requires a low speed gear, the shift control valve 5 distributes the hydraulic oil to the two hydraulic motors A2 and the two hydraulic motors B8. The four hydraulic motors provide a large torque to meet the vehicle's off-road driving, climbing and other driving requirements. When in a high speed gear, the shift control valve 5 distributes the hydraulic oil to the two hydraulic motors A2. The two hydraulic motors A2 are in a small displacement state and rotate at a high speed, thereby driving the gears of the reduction box 6 to rotate at a high speed, thereby achieving high-speed driving capability.

[0040] When changing from low speed to high speed during driving, by operating the shift control valve 5, the drive from two hydraulic motors A2 and two hydraulic motors B8 is converted to the drive from two hydraulic motors A2, and the rotation speed of the two hydraulic motors A2 is increased, thereby increasing the driving speed of the whole vehicle; when changing from high speed to low speed, the drive from two hydraulic motors A2 is converted to the drive from two hydraulic motors A2 and two hydraulic motors B8, and the rotation speed of all motors is reduced, thereby slowly reducing the speed of the whole vehicle; because the shifting is controlled by full hydraulic pressure, the vehicle speed is controlled by changing the number and displacement of the hydraulic motors in operation, and there is no need to limit the vehicle speed or stop, and the gears can be freely shifted at any speed without the technical problem of motor overspeed; at the same time, the balance valve 3 arranged on the hydraulic motor A2 can prevent the vehicle from sliding downhill when going downhill, thereby ensuring the safety of the vehicle.

Claims

1. The gear shifting system of a wheeled excavator is characterized by: The invention comprises a transfer joint (1), a hydraulic motor A (2), a shift control valve (5), a reduction box (6), and a hydraulic motor B (8); the transfer joint (1) is connected to the shift control valve (5); the shift control valve (5) is respectively connected to the hydraulic motor A (2) and the hydraulic motor B (8); the hydraulic motor A (2) and the hydraulic motor B (8) are respectively connected to the reduction box (6); and the reduction box (6) is arranged on a vehicle frame (101).

2. The gear shifting system for a wheeled excavator according to claim 1, characterized in that: The hydraulic motor A (2) is provided with a balancing valve (3), and two or more hydraulic motors A (2) are provided. The liquid outlet and the liquid inlet of the hydraulic motor A (2) are respectively connected to the shift control valve (5) through a single hydraulic motor oil pipe A (4).

3. The gear shifting system for a wheeled excavator according to claim 1, characterized in that: Two or more hydraulic motors B (8) are provided, and the liquid outlet and liquid inlet of the hydraulic motor B (8) are respectively connected to the shift control valve (5) through a single hydraulic motor oil pipe B (7).

4. The gear shifting system for a wheeled excavator according to claim 1, characterized in that: The shift control valve (5) is provided with a switching valve oil pipe (9), one end of the switching valve oil pipe (9) is connected to the shift control valve (5), and the other end of the switching valve oil pipe (9) is connected to the transfer joint (1), and the liquid outlet and liquid inlet of the transfer joint (1) are respectively connected to the transfer joint (1) through a single switching valve oil pipe (9).

5. The gear shifting system for a wheeled excavator according to claim 1, characterized in that: The shift control valve (5) is provided with an end cover (51), a valve stem A (52), and a valve stem B (53). An oil chamber A (54), an oil chamber B (55), an oil chamber C (56), and an oil chamber D (57) are provided in the shift control valve (5). The valve stem A (52) penetrates the oil chamber D (57) for sliding connection. The valve stem B (53) penetrates the oil chamber C (56), the oil chamber B (55), and the oil chamber A (54) in sequence from left to right for sliding connection. The end cover (51) is respectively provided on one side of the valve stem A (52) and the valve stem B (53). The oil chamber A (54) is connected to an oil inlet of a hydraulic motor A (2). The oil chamber B (55) is connected to an oil outlet of the hydraulic motor A (2). The oil chamber C (56) is connected to an oil outlet of a hydraulic motor B (8). The oil chamber D (57) is connected to an oil inlet of the hydraulic motor B (8).

6. The gear shifting system for a wheeled excavator according to claim 5, characterized in that: An opening A (541) is provided on one side of the oil chamber A (54), and an opening B (542) is provided on the other side of the oil chamber A (54). The oil chamber A (54) is communicated with the oil passage A (511) through the opening B (542), and the oil chamber A (54) is communicated with the oil chamber D (57) through the oil passage A (511). One side of the oil chamber B (55) is communicated with the oil passage A (511) through the opening C (551), and the other side of the oil chamber B (55) is communicated with the oil passage A (511) through the opening D (552). The oil chamber C (56) is connected to the oil chamber C (56), an opening E (561) is provided on the other side of the oil chamber C (56), an opening F (571) is provided on one side of the oil chamber D (57), the other side of the oil chamber D (57) is connected to one side of the cavity A (512) through the opening G (572), the other side of the cavity A (512) is connected to one side of the cavity B (513) through the opening H (5121), and the other side of the cavity B (513) is provided with an opening I (5131).

7. The gear shifting system for a wheeled excavator according to claim 5, characterized in that: The valve stem A (52) is provided with a seal A (521), a seal B (522) and a seal C (523); one end of the valve stem A (52) is connected to a guide sleeve (58); the other end of the valve stem A (52) is connected to a control oil block A (59); an oil passage B (591) is provided inside the control oil block A (59); and the oil passage B (591) of the control oil block A (59) is connected to a transfer joint (1).

8. The gear shifting system for a wheeled excavator according to claim 5, characterized in that: The valve stem B (53) is provided with a seal D (531), a seal E (532), a seal F (533), a seal G (534) and a seal H (535); one end of the valve stem B (53) is connected to a guide sleeve (58); the other end of the valve stem B (53) is connected to a control oil block B (510); and the oil passage C (5101) of the control oil block B (510) is connected to a transfer joint (1).

9. The gear shifting system for a wheeled excavator according to claim 5, characterized in that: An elastic member (514) is disposed inside the end cover (51).

10. The shifting method of the shifting system of a wheeled excavator according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: Hydraulic oil enters the shift control valve (5) through the oil chamber A (54). In the low gear, the vehicle servo control system controls the hydraulic oil to push the valve stem A (52) and the valve stem B (53) to move rightward through the control oil block A (59) and the control oil block B (510), respectively, compressing the elastic member (514), so that the oil chamber A (54) and the oil chamber D (57) are in a connected state, and the oil chamber B (55) and the oil chamber C (56) are in a connected state; the hydraulic oil drives the hydraulic motor A (2) and the hydraulic motor B (8) to rotate, and returns the oil through the oil chamber B (55) and the oil chamber C (56) at the same time, and the whole vehicle is driven by the hydraulic motor A (2) and the hydraulic motor B (8) at the same time; S2: When shifting to a high gear, the vehicle servo control system cuts off the oil circuit, the compressed elastic member (514) resumes its extension and pushes the valve stem A (52) and the valve stem B (53) to move to the left, so that the oil chamber A (54) is in a closed state, and the hydraulic oil enters the hydraulic motor A (2) through the oil chamber A (54). The entire vehicle is driven by the hydraulic motor A (2), and the hydraulic motor A (2) is in a high-speed rotation state; in this state, the oil chamber B (55) and the oil chamber D (57) are connected, and the return oil of the hydraulic motor A (2) enters the hydraulic motor B (8) through the oil chamber D (57), so as to flush and lubricate the hydraulic motor B (8).

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