Hydraulic system for car dumper

Abstract

The present invention relates to a hydraulic system for a car dumper, which includes a double-pump and a car pressing control circuit connected to the double-pump. The car pressing control circuit includes a car pressing oil cylinder and a first three-position four-way directional control valve. The first outlet of the double-pump is connected to the first three-position four-way directional control valve. Two oil outlets of the first three-position four-way directional control valve are respectively connected to the rod chamber and the rodless chamber of the car pressing oil cylinder. A first hydraulic control check valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the rod chamber. The hydraulic control circuit of the first hydraulic control check valve is connected to the second outlet of the double-pump through a two-position four-way directional control valve. It provides driving force for the car pressing control circuit through the double-pump, and has a simple structure. After the car pressing oil cylinder is tightened, it is locked and not opened during the whole process of car tipping, ensuring the safety of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of tippers, and particularly to a hydraulic system for tippers. Background Art

[0002] With the continuous development of large industrial enterprises such as domestic power plants, steel plants, and ports, the demand for raw materials (such as coal, iron powder, etc.) is increasing. Therefore, the railway transportation of raw materials (such as coal, iron powder, etc.) is becoming more and more frequent. The tipper system is one of the main ways to unload railway raw materials (such as coal, iron powder, etc.). As an important part of the tipper system, the tipper is responsible for the main equipment for tipping the carriage. Its efficiency and stability are directly related to the unloading capacity of the entire tipper system.

[0003] The existing hydraulic system for tippers mainly relies on the pressing cylinders and the car-resting cylinders to fix and press the carriage. During the tipping process of the carriage, as the materials are dumped, the weight of the train carriage gradually decreases, and the springs at the chassis gradually release the compression caused by the materials. At this time, the reaction force from the carriage acts on the pressing cylinders, which is likely to cause the derailment or even dropping of the carriage. The existing technology conducts the tipping operation by means of a compensation cylinder to release the spring force of the carriage.

[0004] The existing hydraulic system for tippers includes a pressing circuit for controlling the pressing oil rod, a car-resting circuit for controlling the car-resting cylinders, and a balance control circuit (the balance circuit is used to control the compensation cylinder) connected in parallel to the car-resting circuit. Among them, the balance control circuit adjusts the increased oil pressure in the pressing cylinders when the on-board springs (carriage springs) of the tipper recover deformation by controlling the compensation cylinder. During the tipping process, the pressing cylinders need to release the spring force of the carriage in a floating state, and when the volume of the compensation cylinder is reached or when the master switch reaches 100 degrees, the pressing cylinders are locked. In this hydraulic system, in order to adjust the increased oil pressure in the pressing cylinders caused by the recovery deformation of the on-board springs (carriage springs) of the tipper, it is necessary to be achieved through an additional balance control circuit, which has a complex structure and control, is difficult to maintain, and has potential safety hazards during operation. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a hydraulic system for tippers, which has a simple structure, is safe and reliable.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The hydraulic system for a car dumper includes a double-pump and a car pressing control circuit connected to the double-pump. The car pressing control circuit includes a car pressing oil cylinder and a first three-position four-way directional control valve. The first outlet of the double-pump is connected to the first three-position four-way directional control valve. The two oil outlets of the first three-position four-way directional control valve are respectively connected to the rod chamber and the rodless chamber of the car pressing oil cylinder. A first pilot-operated check valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the rod chamber. The pilot control circuit of the first pilot-operated check valve is connected to the second outlet of the double-pump through a two-position four-way directional control valve.

[0008] Further, the neutral position function of the first three-position four-way directional control valve is Y or H type. A first one-way throttle valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the first pilot-operated check valve. A ball valve is arranged on the connecting oil path between the first one-way throttle valve and the first pilot-operated check valve. A second pilot-operated check valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the rodless chamber of the car pressing oil cylinder. A second one-way throttle valve is arranged on the connecting oil path between the second pilot-operated check valve and the rodless chamber of the car pressing oil cylinder. A ball valve is arranged on the connecting oil path between the second one-way throttle valve and the rodless chamber of the car pressing oil cylinder. The pilot control circuit of the second pilot-operated check valve is connected to the oil inlet circuit of the rod chamber of the car pressing oil cylinder. An overflow valve is arranged on the connecting oil path between the two-position four-way directional control valve and the second outlet of the double-pump. A pressure gauge and a one-way valve are arranged in sequence on the connecting oil path between the overflow valve and the second outlet of the double-pump.

[0009] Further, a first pressure relay is arranged on the connecting oil path between the pilot control port of the first pilot-operated check valve and the two-position four-way directional control valve. The first three-position four-way directional control valve is a three-position four-way electro-hydraulic directional control valve. The two-position four-way directional control valve is a two-position four-way electromagnetic directional control valve. A pressure relay is arranged on the pilot control circuit of the second pilot-operated check valve.

[0010] Further, the hydraulic system for the car dumper further includes a car leaning control circuit. The car leaning control circuit includes a car leaning oil cylinder and a second three-position four-way directional control valve. The car leaning oil cylinder is connected to the first outlet of the double-pump through the second three-position four-way directional control valve. A third pilot-operated check valve and a third one-way throttle valve are arranged in sequence on the connecting oil path between one oil outlet of the second three-position four-way directional control valve and the rod chamber of the car leaning oil cylinder. A ball valve is arranged on the connecting oil path between the third pilot-operated check valve and the third one-way throttle valve. A pressure reducing valve, a fourth pilot-operated check valve and a fourth one-way throttle valve are arranged in sequence on the connecting oil path between the other oil outlet of the second three-position four-way directional control valve and the rodless chamber of the car leaning oil cylinder. A ball valve is arranged on the connecting oil path between the pressure reducing valve and the fourth pilot-operated check valve. The pilot control circuit of the third pilot-operated check valve is connected to the oil inlet circuit of the rodless chamber of the car leaning oil cylinder. The pilot control circuit of the fourth pilot-operated check valve is connected to the oil inlet circuit of the rod chamber of the car leaning oil cylinder. The third one-way throttle valve and the fourth one-way throttle valve are integrally arranged.

[0011] Further, the neutral position function of the second three-position four-way directional control valve is of Y type or H type.

[0012] Further, the pressure reducing valve is a one-way pilot-operated pressure reducing valve, the hydraulic control port of the one-way pilot-operated pressure reducing valve is connected to the oil tank, the first three-position four-way directional control valve is a three-position four-way electro-hydraulic directional control valve, and the second three-position four-way directional control valve is a two-three-position four-way electro-hydraulic directional control valve.

[0013] Further, the first outlet of the double-pump is connected to the main oil circuit through a first one-way valve, an electromagnetic overflow valve is arranged on the main oil circuit, and the main oil circuit is respectively connected to the first three-position four-way directional control valve and the second three-position four-way directional control valve.

[0014] Further, the hydraulic system for the car dumper further includes an oil tank, the double-pump is connected to the oil tank, a ball valve and an oil suction filter are arranged on the connecting oil circuit between the double-pump and the oil tank, and the double-pump is driven by a first motor.

[0015] Further, a liquid level gauge, an air filter, a liquid level detection switch and a heater are arranged on the oil tank; a drain ball valve is arranged at the bottom of the oil tank; the oil tank is connected to the return oil pipeline, and a return oil filter is arranged on the return oil pipeline.

[0016] Further, a standby double-pump is also included, the standby double-pump is arranged in parallel with the double-pump, the standby double-pump is driven by a second motor, the standby double-pump is connected to the oil tank, one outlet of the standby double-pump is connected to the main oil circuit through a one-way valve, and the other outlet is connected to the oil inlet of the two-position four-way directional control valve through a one-way valve.

[0017] The beneficial effects of the present invention compared with the prior art are as follows:

[0018] The hydraulic system for the car dumper provided by the present application includes a double-pump and a car pressing control circuit connected to the double-pump. The car pressing control circuit includes a car pressing oil cylinder and a first three-position four-way directional control valve. The first outlet of the double-pump is connected to the first three-position four-way directional control valve. The two oil outlets of the first three-position four-way directional control valve are respectively connected to the rod chamber and the rodless chamber of the car pressing oil cylinder. A first hydraulic control one-way valve is arranged on the connecting oil circuit between the first three-position four-way directional control valve and the rod chamber. The hydraulic control circuit of the first hydraulic control one-way valve is connected to the second outlet of the double-pump through a two-position four-way directional control valve. It provides driving force for the car pressing control circuit through the double-pump, and has a simple structure. After the car pressing oil cylinder is pressed tightly, it is locked and not opened during the whole process of car dumping, ensuring the safety of the equipment. Description of the Drawings

[0019] Figure 1 is the hydraulic schematic diagram of the embodiment of the present invention;

[0020] Figure 2Schematic diagram of the car pressing oil cylinder according to an embodiment of the present invention.

[0021] In the figure: 1. First earring, 2. First cylinder barrel, 2.1 Insertion part, 3. Bolt, 4. Gland, 5. Disc spring, 6. Second piston, 6.1 Annular flange, 7. Inner Seals, 8. Outer Seals, 9. Second cylinder barrel, 9.1 First cavity, 9.2 Second cavity, 9.3 Stopper, 10. Flange, 11. Screw, 12. Dust cover, 13. Piston rod, 14. First piston, 15. Seal, 16. Cylinder tail, 17. First oil port, 18. Second oil port, 19. Second earring, 20. Car pressing oil cylinder, 21. First three-position four-way directional control valve, 22. First pilot-operated check valve, 23. Two-position four-way directional control valve, 24. First pressure relay, 25. Relief valve, 26. First one-way throttle valve, 27. Second pilot-operated check valve, 28. Second one-way throttle valve, 29. Second pressure relay, 30. Oil tank, 31. Liquid level gauge, 32. Air filter, 33. Liquid level detection switch, 34. Heater, 35. Drain ball valve, 36. Return oil filter, 37. Return oil pipeline, 38. First branch oil circuit, 39. Second branch oil circuit, Duplex pump, 41. First outlet, 42. Second outlet, 43. Main oil circuit, 44. Pressure gauge, 45. Suction filter, 46. First motor, 47. Second motor, 48. Electromagnetic relief valve, 49. Spare duplex pump 49, 50. Car supporting oil cylinder, 51. Second three-position four-way directional control valve, 52. Third pilot-operated check valve, 53. Third one-way throttle valve, 54. Pressure reducing valve, 55. Fourth pilot-operated check valve, 56. Fourth one-way throttle valve. Specific embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0023] As Figure 1 shown, the hydraulic system for a car dumper includes: an oil tank 30, a duplex pump 40, a car pressing control circuit, and a car supporting control circuit. A liquid level gauge 31, an air filter 32, a liquid level detection switch 33, and a heater 34 are provided on the oil tank 30; a drain ball valve 35 is provided at the bottom of the oil tank 30, and the oil tank 30 is connected to a return oil pipeline 37, and a return oil filter 36 is provided on the return oil pipeline 37.

[0024] The double-pump 40 is connected to the fuel tank 30. A ball valve and an oil suction filter 45 are provided on the connecting oil path between the double-pump 40 and the fuel tank 30. The double-pump 40 is driven by a first motor 46. The double-pump 40 includes a first outlet 41 and a second outlet 42. The first outlet 41 of the double-pump 40 is connected to the main oil path 43 through a check valve. A pressure gauge 44 and an electromagnetic overflow valve 48 are provided on the main oil path 43. The pressure gauge 44 is located upstream of the electromagnetic overflow valve 48. The electromagnetic overflow valve 48 is composed of a pilot-operated overflow valve and a normally-open two-position two-way solenoid valve. The hydraulic control port of the pilot-operated overflow valve is connected to the normally-open two-position two-way solenoid valve. The double-pump 40 in this example is a vane pump, and the vane pump is connected to the first motor 46 through an elastic coupling. It should be noted that the double-pump 40 has one oil suction port and two pressure outlets (the first outlet 41 and the second outlet 42), can be driven by one motor 46, saves space, has a high rated pressure, low noise, and high efficiency.

[0025] The truck pressing control circuit is connected to the double-pump 40. The truck pressing control circuit includes a truck pressing oil cylinder 20 and a first three-position four-way directional control valve 21. The first outlet 41 of the double-pump 40 is connected to the first three-position four-way directional control valve 21. Two oil outlets of the first three-position four-way directional control valve 21 are respectively connected to the rod chamber and the non-rod chamber of the truck pressing oil cylinder 20. The oil inlet of the first three-position four-way directional control valve 21 is connected to the main oil path 43 through a first branch oil path 38. The oil return port of the first three-position four-way directional control valve 21 is connected to the oil return pipeline 37. When the first three-position four-way directional control valve 21 is in the middle position, the two oil outlets of the first three-position four-way directional control valve 21 are communicated with the oil return port. At this time, the remaining pressure in the pipeline can be released to prevent the second hydraulic control check valve 27 from being accidentally opened due to the remaining pressure in the pipeline. The middle position function of the first three-position four-way directional control valve 21 is of Y type or H type (that is, the connection mode of the oil inlet oil paths of the rod chamber and the non-rod chamber of the truck pressing oil cylinder 20 is floating connection). In this embodiment, the middle position function of the first three-position four-way directional control valve 21 is of Y type. The first three-position four-way directional control valve 21 can be manual, electromagnetic or electro-hydraulic. The first three-position four-way directional control valve 21 in this example is a three-position four-way electro-hydraulic directional control valve. When in the middle position, its oil return port is communicated with the two oil outlets, and the oil inlet is closed.

[0026] A first three-position four-way directional control valve 21 is provided with a first pilot-operated check valve 22 on the connecting oil path to the rod chamber of the car pressing oil cylinder 20. The pilot control circuit of the first pilot-operated check valve 22 is connected to the second outlet 42 of the double-pump 40 through a two-position four-way directional control valve 23. A first pressure relay 24 is provided on the connecting oil path between the pilot control port of the first pilot-operated check valve 22 and the two-position four-way directional control valve 23. In this embodiment, the pilot control port of the first pilot-operated check valve 22 is connected to one of the oil outlets of the two-position four-way directional control valve 23. The other oil outlet of the two-position four-way directional control valve 23 is connected to the fuel tank 30 through an oil return pipeline 37. The inlet port of the two-position four-way directional control valve 23 is connected to the second outlet 42 of the double-pump 40, and the oil return port of the two-position four-way directional control valve 23 is directly connected to the fuel tank 30 through a pipeline. In the first working position of the two-position four-way directional control valve 23, the inlet oil path is in communication with the fuel tank 30, and the pilot control circuit of the first pilot-operated valve is in communication with the fuel tank 30; in the second working position of the two-position four-way directional control valve 23, the inlet oil path is in communication with the pilot control circuit of the first pilot-operated check valve 22. An overflow valve 25 is provided on the connecting oil path between the two-position four-way directional control valve 23 and the second outlet 42 of the double-pump 40. A pressure gauge 44 and a check valve are sequentially provided on the connecting oil path between the overflow valve 25 and the second outlet 42 of the double-pump 40. The overflow valve 25 can be a direct-acting type or a pilot-operated type. The overflow valve 25 in this embodiment is a pilot-operated overflow valve 25, and the oil outlet of the overflow valve 25 is connected to the fuel tank 30. The two-position four-way directional control valve 23 can be a manual type or an electromagnetic type. The two-position four-way directional control valve 23 in this embodiment is a two-position four-way electromagnetic directional control valve. When it is de-energized, the inlet oil path is in communication with the fuel tank 30, and the pilot control circuit of the first pilot-operated check valve 22 is in communication with the fuel tank 30. When it is energized, the inlet oil path is in communication with the pilot control circuit of the first pilot-operated check valve 22.

[0027] A first one-way throttle valve 26 and a ball valve are sequentially provided on the connecting oil path between the first three-position four-way directional control valve 21 and the first pilot-operated check valve 22; a second pilot-operated check valve 27, a second one-way throttle valve 28 and a ball valve are sequentially provided on the connecting oil path between the first three-position four-way directional control valve 21 and the rodless chamber of the car pressing oil cylinder 20. The first one-way throttle valve 26 and the second one-way throttle valve 28 are integrally provided. The pilot control circuit of the second pilot-operated check valve 27 is connected to the inlet oil circuit of the rod chamber of the car pressing oil cylinder 20; the node where the pilot control circuit of the second pilot-operated check valve 27 is connected to the inlet oil circuit is located upstream of the first one-way throttle valve 26, and a second pressure relay 29 is provided on the pilot control circuit of the second pilot-operated check valve 27. It should be noted that the pilot control circuit of the first pilot-operated check valve 22 in this example is supplied with oil separately through the second oil outlet 42 of the double-pump 40, which can prevent the influence of the back pressure of the car pressing oil cylinder 20, resulting in the phenomenon that the first pilot-operated check valve 22 cannot be opened when the back pressure of the car pressing oil cylinder 20 is too high. Cooperating with the first pressure relay 24 can detect the car pressing control circuit.

[0028] To provide sufficient power, eight car pressing cylinders 20 in this embodiment are arranged in parallel on the car pressing control circuit.

[0029] In the above technical solution, a double-pump is used to provide driving force for the car pressing control circuit, making the hydraulic system of the dumper simple and efficient. After the car pressing cylinder is tightened, it is locked and not opened during the whole dumper process, ensuring the safety of the equipment. And it can automatically compensate and release the spring force of the car body.

[0030] By setting the first three-position four-way directional control valve 21 in this embodiment as an electro-hydraulic type and the two-position four-way directional control valve 23 as an electromagnetic type, it is convenient to cooperate with the first pressure relay 24, the second pressure relay 29 and the electromagnetic overflow valve 48, which is beneficial to the transmission of pressure information and convenient for the precise control of the car pressing process.

[0031] The hydraulic system for the dumper described in this application further includes a car leaning control circuit. The car leaning control circuit is arranged in parallel with the car pressing control circuit. The car leaning control circuit is connected to the first outlet 41 of the double-pump 40. The car leaning control circuit includes a car leaning cylinder 50 and a second three-position four-way directional control valve 51. The car leaning cylinder 50 is connected to the first outlet 41 of the double-pump 40 through the second three-position four-way directional control valve 51. A third hydraulic check valve 52, a ball valve and a third one-way throttle valve 53 are sequentially arranged on the connecting oil path between one oil outlet of the second three-position four-way directional control valve 51 and the rod chamber of the car leaning cylinder 50. A pressure reducing valve 54, a ball valve, a fourth hydraulic check valve 55 and a fourth one-way throttle valve 56 are sequentially arranged on the connecting oil path between the other oil outlet of the second three-position four-way directional control valve 51 and the rodless chamber of the car leaning cylinder 50. The oil inlet of the second three-position four-way directional control valve 51 is connected to the main oil path 43 through the second branch oil path 39. The oil return port of the second three-position four-way directional control valve 51 is connected to the oil return pipeline 37.

[0032] The hydraulic control circuit of the third hydraulic check valve 52 is connected to the oil inlet circuit of the rodless cavity of the car-resting oil cylinder 50, and the hydraulic control circuit of the fourth hydraulic check valve 55 is connected to the oil inlet circuit of the rodless cavity of the car-resting oil cylinder 50. The third one-way throttle valve 53 and the fourth one-way throttle valve 56 are integrally arranged. The pressure reducing valve 54 is a one-way pilot-operated pressure reducing valve 54. The hydraulic control port of the one-way pilot-operated pressure reducing valve 54 is connected to the oil tank 30. When the second three-position four-way directional control valve 51 is in the neutral position, the two oil outlet ports of the second three-position four-way directional control valve 51 are communicated with the oil return port, which can release the residual pressure in the pipeline and prevent the third hydraulic check valve 52 and the fourth hydraulic check valve 55 from being accidentally opened due to the residual pressure in the pipeline. The neutral position function of the second three-position four-way directional control valve 51 is of Y type or H type (that is, the connection mode of the oil inlet circuits of the rodless cavity and the rod cavity of the car-resting oil cylinder 50 is floating connection). In this embodiment, the neutral position function of the second three-position four-way directional control valve 51 is of Y type. The second three-position four-way directional control valve 51 can be manual, electromagnetic or electro-hydraulic. In this embodiment, the second three-position four-way directional control valve 51 is a three-position four-way electro-hydraulic directional control valve. When in the neutral position, its oil return port is communicated with the two oil outlet ports, and the oil inlet port is closed. In order to provide sufficient power, four car-resting oil cylinders 50 are arranged in this embodiment, and the four car-resting oil cylinders 50 are arranged in parallel on the car-resting control circuit.

[0033] The hydraulic system for the dumper described in this application further includes a standby double-pump 49. The standby double-pump 49 is arranged in parallel with the double-pump 40. The standby double-pump 49 is driven by a second motor 47. The standby double-pump 49 is connected to the oil tank 30. One outlet of the standby double-pump 49 is connected to the main oil circuit 43 through a one-way valve, and the other outlet is connected to the oil inlet port of the two-position four-way directional control valve 23 through a one-way valve, a pressure gauge 44 and a relief valve 25. Only one set of double-pumps 40 works during use. It should be noted that the two sets of motor-pump units can be seamlessly switched and maintained online to ensure the stable operation of the equipment.

[0034] It should be noted that the first three-position four-way directional control valve 21, the two-position four-way directional control valve 23, the first pressure relay 24, the relief valve 25, the first one-way throttle valve 26, the second hydraulic check valve 27, the second one-way throttle valve 28, the second pressure relay 29, the pressure gauge 44, the electromagnetic relief valve 48, the second three-position four-way directional control valve 51, the third hydraulic check valve 52 and the pressure reducing valve 54 in this embodiment are integrated together.

[0035] Action implementation process:

[0036] When pressing the car, the electromagnets YV1 (two-position two-way solenoid valve) and YV3 (left working position of the first three-position four-way directional valve 21) are energized. The hydraulic oil coming out of the first outlet 41 of the double-pump 40 enters the check valve, the first three-position four-way directional valve 21, the hydraulic control circuit of the second hydraulic control check valve 27 (opening the second hydraulic control check valve 27 to make it conduct reversely), and the first one-way throttle valve 26. It passes through 1B and the first hydraulic control check valve 22 to push the piston rod of the car pressing cylinder 20 to perform the car pressing action until the car pressing mechanism contacts the train carriage. After the car pressing reverse signal is sent by the second pressure relay 29, YV1 (two-position two-way solenoid valve) and YV3 (left working position of the first three-position four-way directional valve 21) are de-energized and the action stops. The hydraulic oil coming out of the second outlet 42 of the double-pump 40 enters the check valve, passes through the two-position four-way directional valve 23 and the return oil filter 36, and returns to the hydraulic oil tank 30 to realize the no-load cycle.

[0037] During the tipping process: The car pressing cylinder 20 is in a fully locked state under the action of the first hydraulic control check valve 22. As the material is tipped, the weight of the train carriage gradually decreases, and the springs of the chassis gradually release the compression caused by the material. At this time, it acts on the piston rod of the car pressing cylinder 20 through the carriage reaction. The disc spring arranged inside the rod chamber of the car pressing cylinder 20 is compressed, and the piston rod is stretched to realize the release of the carriage spring force.

[0038] When the car pressing returns: The electromagnet YV2 (two-position four-way directional valve 23) is energized. The hydraulic oil coming out of the second outlet 42 of the double-pump 40 enters the check valve, the overflow valve 25, the two-position four-way directional valve 23, and the hydraulic control circuit of the first hydraulic control check valve 22, opening the first hydraulic control check valve 22. After confirmation by the first pressure relay 24, YV1 (two-position two-way solenoid valve) and YV4 (right working position of the first three-position four-way directional valve 21) are energized. The hydraulic oil coming out of the first outlet 41 of the double-pump 40 enters the check valve, the first three-position four-way directional valve 21, the second hydraulic control check valve 27, and the second one-way throttle valve 28, passes through 1A, and pushes the car pressing cylinder 20 to extend until the car pressing mechanism contacts the limit, and then YV1 (two-position two-way solenoid valve), YV2 (two-position four-way directional valve 23), and YV4 (right working position of the first three-position four-way directional valve 21) are de-energized and stop.

[0039] When leaning against the car: YV1 (two-position two-way solenoid valve) and YV5 (left working position of the second three-position four-way directional valve 51) are energized. The hydraulic oil coming out of the first outlet 41 of the double-pump 40 enters the check valve, the second three-position four-way directional valve 51, the hydraulic control circuit of the third hydraulic control check valve 52 (opening the third hydraulic control check valve 52), the pressure reducing valve 54, the fourth hydraulic control check valve 55, and the fourth one-way throttle valve 56 to push the car leaning cylinder 50 to extend. The hydraulic oil coming out of the second outlet 42 of the double-pump 40 enters the check valve, passes through the two-position four-way directional valve 23 and the return oil filter 36, and returns to the hydraulic oil tank 30 to realize the no-load cycle.

[0040] When the car-approaching is in the reverse state: YV1 (two-position two-way solenoid valve) and YV6 (right working position of the second three-position four-way directional control valve 51) are energized. The hydraulic oil coming out from the first outlet 41 of the double-pump 40 enters the hydraulic control circuits of the check valve, the second three-position four-way directional control valve 51, the third hydraulic control check valve 52, the fourth hydraulic control check valve 55 (opening the fourth hydraulic control check valve 55), and the third one-way throttle valve 53, and pushes the car-approaching oil cylinder 50 to retract. The hydraulic oil coming out from the second outlet 42 of the double-pump 40 enters the check valve, passes through the two-position four-way directional control valve 23, and returns to the hydraulic oil tank 30 through the oil return filter 36 to achieve no-load circulation.

[0041] The beneficial effects of this embodiment compared with the prior art are as follows:

[0042] 1. The car-pressing control circuit and the car-approaching control circuit provide hydraulic power through the double-pump 40, enabling the dumper to perform tipping operations. The structure is simple, the operation is convenient, and it is safe and reliable;

[0043] 2. During the entire tipping process, the car-pressing oil cylinder 20 is in a locked state, making the hydraulic system safer;

[0044] 3. The integrated block has a smaller volume, saves more space, and is lighter in weight;

[0045] 4. The two sets of motor-pump units can be seamlessly switched and maintained online to ensure the stable operation of the equipment;

[0046] 5. By setting the first three-position four-way directional control valve 21 and the second three-position four-way directional control valve 51 in this embodiment as electro-hydraulic type, and setting the two-position four-way directional control valve 23 as electromagnetic type, it is convenient to cooperate with the first pressure relay 24, the second pressure relay 29, and the electromagnetic overflow valve 48, which is beneficial to the transmission of pressure information and convenient for the control of the hydraulic system of the dumper.

[0047] It should be noted that a return spring is provided in the rod chamber of the car-pressing oil cylinder 20, and the return spring can compensate for the excess pressure in the rod chamber of the hydraulic oil cylinder. It can be understood that as long as a hydraulic oil cylinder capable of realizing the pressure compensation function is provided in the rod chamber of the hydraulic oil cylinder, the above technical effects can be achieved, and the technical problems to be solved by this application can be solved. This embodiment discloses a preferred car-pressing oil cylinder 20, such as Figure 2As shown in the figure, a truck pressing oil cylinder 20 includes a first cylinder barrel 2, a second cylinder barrel 9, a first piston 14, a second piston 6, a cylinder tail 16, and a piston rod 13. One end of the first cylinder barrel 2 is fixedly welded to the cylinder tail 16, and the other end of the first cylinder barrel 2 is sealingly connected to the second cylinder barrel 9. The first cylinder barrel 2 and the second cylinder barrel 9 are coaxially arranged and communicate with each other. One end of the second cylinder barrel 9 away from the first cylinder barrel 2 is fixedly connected to a gland 4 through a first bolt 3. The piston rod 13 passes through the gland 4 and is located in the cavity formed by the first cylinder barrel 2 and the second cylinder barrel 9, and can perform telescopic movement in the cavity formed by the first cylinder barrel 2 and the second cylinder barrel 9. The first piston 14 is located in the first cylinder barrel 2, and the first piston 14 is fixedly connected to one end of the piston rod 13. It should be noted that the first piston 14 and the piston rod 13 can be fixed by welding or threaded connection. In this example, the first piston 14 and the piston rod 13 are threadedly connected. The second piston 6 is located in the second cylinder barrel 9, and the second piston 6 can move in the second cylinder barrel 9. The second piston 6 is slidably connected to the piston rod 13. A first oil port 17 is provided on the cylinder tail 16, and the first oil port 17 communicates with the first cylinder barrel 2. A second oil port 18 is provided on the second cylinder barrel 9, and the second oil port 18 is located between the first piston 14 and the second piston 6, and the second oil port 18 communicates with the second cylinder barrel 9.

[0048] A compression elastic member is provided between the second piston 6 and the gland 4; the compression elastic member can expand and contract with the change of the oil pressure in the truck pressing oil cylinder 20, and the elastic force (pre-tightening force) of the compression elastic member is greater than the pressure of the hydraulic oil when the truck pressing oil cylinder 20 is working (that is, when the piston rod 13 drives the load to expand and contract). During use, when the tensile force received by the piston rod 13 increases to the pre-tightening force of the compression elastic member, the compression elastic member will be compressed, causing the piston rod 13 to drive the piston 14 to move upward (extend outward). It should be noted that the pre-tightening force of the compression elastic member can be set according to the actual working needs. The compression elastic member presses the second piston 6 against one side of the second cylinder barrel 9 close to the first cylinder barrel 2. The compression elastic member can play a buffering role when the second piston 6 moves in the second cylinder barrel 9 towards the end away from the first cylinder barrel 2. At the same time, the compression elastic member and the second piston 6 cooperate to adjust the volume of the cavity of the second cylinder barrel 9, thereby changing the volume of the cavity of the truck pressing oil cylinder 20 formed by the first cylinder barrel 2 and the second cylinder barrel 9, and finally enabling the piston rod 13 to achieve flexible expansion and contraction according to the change of the load position during the working process (oil inlet into the rod chamber). The compression elastic member is a spring or a disc spring 5. The spring or the disc spring 5 is sleeved on the piston rod 13. One end of the spring or the disc spring 5 abuts against the gland 4, and the other end abuts against the second piston 6. The compression elastic member in this example is a disc spring 5. The selection of the disc spring 5 can increase the adjustment ability (i.e., the pre-tightening force) while reducing the volume of the oil cylinder.

[0049] It should be noted that the second piston 6 in the above technical solution will not displace during the normal telescoping of the piston rod 13 (i.e., the normal operation of the oil cylinder). Only when the piston rod 13 telescopes into the first cylinder barrel 2 and self-locks, and the oil pressure in the rod chamber of the first cylinder barrel 2 continues to increase, will the second piston 6 move within the second cylinder barrel 9. The design of the above technical solution can adjust the volume of the cavity of the second cylinder barrel 9 according to the change of the oil pressure in the rod chamber of the pressing vehicle oil cylinder 20 through the second piston 6 and the disc spring 5 arranged in the second cylinder barrel 9, realizing the flexible telescoping of the piston rod 13, thereby achieving automatic compensation and improving the working stability of the pressing vehicle oil cylinder 20.

[0050] To improve the sealing performance of the oil cylinder, a seal 15 is provided between the first piston 14 and the first cylinder barrel 2; an outer W-shaped seal 8 is provided between the second piston 6 and the second cylinder barrel 9, and an inner W-shaped seal 7 is provided between the second cylinder barrel 9 and the piston rod 13.

[0051] To facilitate the connection between the pressing vehicle oil cylinder 20 and external equipment, a first earring 1 is provided on the outer end face of the cylinder tail 16, and a second earring 19 is provided at one end of the piston rod 13 away from the first piston 14. A dust cover 12 is provided outside the gland 4. One end of the dust cover 12 is fixed to the gland 4, and the other end is fixed to the end of the piston rod 13. The dust cover 12 is used to isolate and seal the part of the piston rod 13 exposed to the outside from the outside world.

[0052] In this embodiment, a plug-in part 2.1 is provided at one end of the first cylinder barrel 2 close to the second cylinder barrel 9. The plug-in part 2.1 is inserted into the stop 9.3 in the second cylinder barrel 9, and the plug-in part 2.1 is in sealing cooperation with the stop 9.3. The insertion of the first cylinder barrel 2 and the second cylinder barrel 9 can improve the sealing performance. A flange 10 is fixedly provided at one end of the first cylinder barrel 2 close to the second cylinder barrel 9. A screw 11 passes through the through hole in the flange 10 and is fastened in the corresponding threaded hole on the end face of the second cylinder barrel 9. The first cylinder barrel 2 and the second cylinder barrel 9 are fixedly connected through the flange 10 and the screw 11, which can improve the sealing performance and rigidity.

[0053] The second cylinder 9 in this embodiment includes a first cavity 9.1 and a second cavity 9.2. The first cavity 9.1 and the second cavity 9.2 are two stepped hole structures. The inner diameter of the first cavity 9.1 is smaller than that of the second cavity 9.2. The first cavity 9.1 is located on the side close to the first cylinder 2. A Vespel seal 8 is arranged between one end of the second piston 6 and the first cavity 9.1. The other end of the second piston 6 is located in the second cavity 9.2. An annular flange 6.1 is arranged on the second piston 6. The annular flange 6.1 is located in the second cavity 9.2. A disc spring 5 is arranged between the annular flange 6.1 and the gland 4. The disc spring 5 is sleeved on the second piston 6. One end of the disc spring 5 abuts against the side of the annular flange 6.1 close to the gland 4, and the other end abuts against the inner wall of the gland 4. It should be noted that the disc spring 4 in this embodiment can be replaced with a spring.

[0054] During use, in the absence of pressure, the disc spring 5 is in a released state, and the side of the annular flange 6.1 away from the gland 4 abuts against the stepped surface of the stepped hole. It should be noted that when there is no pressure, the disc spring 5 can also be in a micro energy storage (micro compression) state. The disc spring 5 restricts the movement of the second piston 6 in the second cylinder 9 through its own elasticity. When the tensile force on the piston rod 13 increases to the pre-tightening force of the disc spring 5, the disc spring 5 will be compressed, causing the piston rod 13 to drive the piston 14 to move upward (extend outward).

[0055] The arrangement of the first cavity 9.1 and the second cavity 9.2 can ensure the sealing between the second piston 6 and the second cylinder 9 while also improving the energy storage capacity of the disc spring 5 during compression. Thus, a greater compensation performance can be exerted. It should be noted that the sizes of the first cavity 9.1 and the second cavity 9.2 can be designed according to actual needs.

[0056] During use, when oil enters the first oil port 17, the first piston 14 moves leftward under the push of hydraulic oil, and the piston rod 13 extends. When it moves to the leftmost limit, the first piston 14 stops moving and reaches the left end point. When oil enters the second oil port 18, the first piston 14 moves rightward under the push of hydraulic oil, and the piston rod 13 contracts. When it moves to the rightmost limit, the first piston 14 stops moving and reaches the right end point. At this time, when the piston rod 13 is subject to a reaction force (i.e., a force that stretches it outward), the pressure of the second oil port 18 will increase. When the pressure value of the second oil port 18 continuously rises to overcome the elastic force (pre-tightening force) of the disc spring 5 itself, the disc spring 5 compresses, and the second piston 6 moves in the direction close to the gland 4 (i.e., moves leftward), and the piston rod 13 extends a certain distance (i.e., moves leftward) to release the excess pressure to achieve a compensation effect. When the reaction force (i.e., a force that stretches it outward) acting on the piston rod 13 disappears, the pressure value of the second oil port 18 decreases, and the disc spring 5 relies on its own elastic force to reset the second piston 6. Under the action of the pressure oil in the rod chamber, the first piston 14 drives the piston rod 13 to contract. And finally, it is ensured that the piston rod 13 realizes flexible telescoping during the contraction operation.

[0057] It should be noted that during use, the car pressing oil cylinder 20 is installed on the car pressing device of the dumper, and the piston rod 13 is drivingly connected to the car pressing device. The process of the piston rod 13 contracting and moving is the process in which the car pressing device approaches, contacts, and fixes the train carriage. When the piston rod 13 contracts and moves a certain distance, the car pressing device driven by the piston rod 13 completes the fixation of the train carriage. To ensure the stability of the relative position between the car pressing device and the train carriage, at this time, the car pressing oil cylinder 20 is in a self-locking state under the action of the first hydraulic control one-way valve 22 on the car pressing control loop. As the material is overturned, the weight of the train carriage gradually decreases, and the springs of the chassis gradually release the compression amount caused by the material. At this time, it acts on the piston rod 13 through the reaction of the carriage, which will cause the pressure of the second oil port 18 (i.e., the rod chamber) to increase. When the pressure value of the second oil port 18 continuously rises to overcome the elastic force (pre-tightening force) of the disc spring 5 itself, the disc spring 5 compresses, and the second piston 6 moves in the direction close to the gland 4 (i.e., moves leftward), thereby increasing the volume of the cavity of the second cylinder barrel 9, and the piston rod 13 is stretched out a certain distance to release the excess pressure to achieve a compensation effect, ensuring the relative stability between the car pressing device and the train carriage. It avoids the possibility that the train carriage derails or even falls off due to the piston rod 13 being subject to the reaction force from the carriage during the car pressing operation, which causes the train carriage to deviate from the positioning limit of the car pressing device.

[0058] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent replacements or changes, shall be covered by the protection scope of the present invention.

Claims

1. Hydraulic system for a car dumper, characterized in that: It includes a double pump and a car pressing control circuit connected to the double pump. The car pressing control circuit includes a car pressing oil cylinder and a first three-position four-way directional control valve. The first outlet of the double pump is connected to the first three-position four-way directional control valve. The two oil outlets of the first three-position four-way directional control valve are respectively connected to the rod chamber and the rodless chamber of the car pressing oil cylinder. A first pilot-operated check valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the rod chamber. The pilot control circuit of the first pilot-operated check valve is connected to the second outlet of the double pump through a two-position four-way directional control valve. The neutral position function of the first three-position four-way directional control valve is of Y type or H type. A first one-way throttle valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the first pilot-operated check valve. A ball valve is arranged on the connecting oil path between the first one-way throttle valve and the first pilot-operated check valve. A second pilot-operated check valve is arranged on the connecting oil path between the first three-position four-way directional control valve and the rodless chamber of the car pressing oil cylinder. A second one-way throttle valve is arranged on the connecting oil path between the second pilot-operated check valve and the rodless chamber of the car pressing oil cylinder. A ball valve is arranged on the connecting oil path between the second one-way throttle valve and the rodless chamber of the car pressing oil cylinder. The pilot control circuit of the second pilot-operated check valve is connected to the oil inlet circuit of the rod chamber of the car pressing oil cylinder. An overflow valve is arranged on the connecting oil path between the two-position four-way directional control valve and the second outlet of the double pump. A pressure gauge and a check valve are arranged in sequence on the connecting oil path between the overflow valve and the second outlet of the double pump. A return spring is arranged in the rod chamber of the car pressing oil cylinder, and the return spring compensates the pressure in the rod chamber of the hydraulic oil cylinder.

2. The hydraulic system for a car dumper according to claim 1, wherein: A first pressure relay is arranged on the connecting oil path between the pilot control port of the first pilot-operated check valve and the two-position four-way directional control valve. The first three-position four-way directional control valve is a three-position four-way electro-hydraulic directional control valve. The two-position four-way directional control valve is a two-position four-way electromagnetic directional control valve. A pressure relay is arranged on the pilot control circuit of the second pilot-operated check valve.

3. The hydraulic system for a car dumper according to claim 1, characterized in that: The hydraulic system for the dumper also includes a car leaning control circuit. The car leaning control circuit includes a car leaning oil cylinder and a second three-position four-way directional control valve. The car leaning oil cylinder is connected to the first outlet of the double pump through the second three-position four-way directional control valve. A third pilot-operated check valve and a third one-way throttle valve are arranged in sequence on the connecting oil path between one oil outlet of the second three-position four-way directional control valve and the rod chamber of the car leaning oil cylinder. A ball valve is arranged on the connecting oil path between the third pilot-operated check valve and the third one-way throttle valve. A pressure reducing valve, a fourth pilot-operated check valve and a fourth one-way throttle valve are arranged in sequence on the connecting oil path between the other oil outlet of the second three-position four-way directional control valve and the rodless chamber of the car leaning oil cylinder. A ball valve is arranged on the connecting oil path between the pressure reducing valve and the fourth pilot-operated check valve. The pilot control circuit of the third pilot-operated check valve is connected to the oil inlet circuit of the rodless chamber of the car leaning oil cylinder. The pilot control circuit of the fourth pilot-operated check valve is connected to the oil inlet circuit of the rod chamber of the car leaning oil cylinder. The third one-way throttle valve and the fourth one-way throttle valve are integrally arranged.

4. The hydraulic system for a car dumper according to claim 3, wherein: The neutral position function of the second three-position four-way directional control valve is of Y type or H type.

5. The hydraulic system for a car dumper according to claim 3, characterized in that: The pressure reducing valve is a one-way pilot-operated pressure reducing valve, the hydraulic control port of the one-way pilot-operated pressure reducing valve is connected to the oil tank, the first three-position four-way directional control valve is a three-position four-way electro-hydraulic directional control valve, and the second three-position four-way directional control valve is a two-three-position four-way electro-hydraulic directional control valve.

6. The hydraulic system for a car dumper according to claim 3, wherein: The first outlet of the double pump is connected to the main oil circuit through a one-way valve, an electromagnetic overflow valve is arranged on the main oil circuit, and the main oil circuit is respectively connected to the first three-position four-way directional control valve and the second three-position four-way directional control valve.

7. The hydraulic system for a car dumper according to any one of claims 1-6, characterized in that: The hydraulic system for the car dumper further includes an oil tank, the double pump is connected to the oil tank, a ball valve and an oil suction filter are arranged on the connecting oil circuit between the double pump and the oil tank, and the double pump is driven by a first motor.

8. The hydraulic system for a car dumper according to claim 7, characterized in that: A liquid level gauge, an air filter, a liquid level detection switch and a heater are arranged on the oil tank; a drain ball valve is arranged at the bottom of the oil tank; the oil tank is connected to the oil return pipeline, and an oil return filter is arranged on the oil return pipeline.

9. The hydraulic system for a car dumper according to claim 7, characterized in that: The hydraulic system for the car dumper further includes a spare double pump, the spare double pump is arranged in parallel with the double pump, the spare double pump is driven by a second motor, the spare double pump is connected to the oil tank, one outlet of the spare double pump is connected to the main oil circuit through a one-way valve, and the other outlet is connected to the oil inlet of the two-position four-way directional control valve through a one-way valve.

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