People ascending vehicle and hydraulic system thereof

Abstract

The hydraulic system comprises a hydraulic control valve set connected into a hydraulic oil way, and the hydraulic control valve set comprises a proportional direction valve and a flow priority valve; when the proportional direction valve is small in opening degree, the flow priority valve works at the left position, and a lifting action oil way of the vehicle is conducted; when the proportional direction valve is in a large opening degree, the right position of the flow priority valve works, and an auxiliary action oil way of the vehicle is conducted; an unloading electromagnetic valve is arranged on the unloading oil way before the flow priority valve enters the vehicle lifting action oil way, when the flow priority valve works at the right position, a channel, connected to the oil return oil tank, of the unloading electromagnetic valve is opened, and redundant hydraulic oil passing through the flow priority valve to the lifting oil way directly returns through the unloading electromagnetic valve. The scheme can reduce energy consumption, prevent the output flow of the hydraulic pump from exceeding the actual demand, reduce the calorific value of the system and prolong the service life of hydraulic parts.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles for people to go up, and in particular to a vehicle for people to go up and a hydraulic system thereof. Background Art

[0002] With the continuous development of logistics technology, the labor cost is constantly increasing, and the warehouse shelves are getting higher and higher. As a result, the use of manned vehicles for picking is becoming more and more extensive, including manned three-way stackers, manned picking vehicles, etc. The main features of each manned vehicle are hydraulic transmission, high door frame, and heavy load when empty.

[0003] Since the hydraulic transmission system of the existing manned three-way stacker has a low degree of refinement and high energy consumption, it is necessary to reselect the main hydraulic components and optimize the hydraulic system principles and control strategies to improve energy utilization. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a person-moving vehicle and a hydraulic system thereof, which can reduce energy consumption and achieve the goals of energy saving, high efficiency and precise control.

[0005] A hydraulic system for a vehicle for people going up, comprising:

[0006] Motor,

[0007] A bidirectional gear pump driven by the motor to deliver hydraulic oil to the hydraulic oil circuit in a forward or reverse direction;

[0008] A hydraulic control valve group connected to the hydraulic oil circuit, the hydraulic control valve group includes a proportional directional valve and a flow priority valve; the proportional directional valve switches between a small opening and a large opening, and the flow priority valve switches between working in the left position and working in the right position; when the proportional directional valve is in a small opening, the flow priority valve works in the left position, the lifting action oil circuit of the vehicle is connected, and the auxiliary action oil circuit is cut off; when the proportional directional valve is in a large opening, the flow priority valve works in the right position, the auxiliary action oil circuit of the vehicle is connected, and the lifting action oil circuit is cut off;

[0009] A unloading solenoid valve is provided on the unloading oil circuit before the flow priority valve enters the vehicle lifting action oil circuit. When the flow priority valve is in the right position, the passage connecting the unloading solenoid valve to the return oil tank is opened, and the excess hydraulic oil that passes through the flow priority valve to the lifting oil circuit is directly returned through the unloading solenoid valve.

[0010] Preferably, a pressure relief oil circuit directly connected to the output end of the unloading solenoid valve is provided on the oil circuit between the outflow end of the proportional directional valve and the inflow port of the right position of the flow priority valve, and a damping hole is provided on the pressure relief oil circuit.

[0011] Preferably, a first one-way valve is provided between the flow priority valve and the lifting action oil circuit, and a second one-way valve is provided between the flow priority valve and the auxiliary action oil circuit.

[0012] Preferably, the direction from the first end to the second end of the first one-way valve is the conduction direction, the input end of the unloading oil circuit is connected to the first end of the first one-way valve, and the output end of the unloading oil circuit is connected to the return oil tank; the input end of the return oil circuit of the vehicle's lifting action oil circuit is connected to the second end of the first one-way valve, and the output end of the return oil circuit of the lifting action oil circuit is connected to the bidirectional gear pump.

[0013] Preferably, an oil return filter is provided at the output end of the unloading oil circuit.

[0014] Preferably, a control knob is included, and the control knob controls the current of the proportional directional valve to achieve a linear change in the opening of the directional valve; the control knob also performs linkage speed control on the output power of the motor.

[0015] Preferably, the relationship between the current of the proportional directional valve and the output power of the motor is preset according to the matching performance of the required flow of the lifting cylinder and the main gantry cylinder and the output flow of the bidirectional gear pump, and the control knob controls the proportional directional valve and the motor in linkage according to the preset relationship.

[0016] Preferably, a proportional flow valve, a descending solenoid valve and a return oil back pressure valve are provided on the return oil circuit of the vehicle's lifting action oil circuit. When the vehicle is descending, the proportional flow valve and the descending solenoid valve are opened, and the hydraulic oil returning from the vehicle's lifting action oil circuit passes through the proportional flow valve, the descending solenoid valve and the return oil back pressure valve and enters the bidirectional gear pump.

[0017] Preferably, it also includes an emergency oil return circuit, on which an emergency lowering valve is provided, and the hydraulic oil returning from the vehicle's lifting action oil circuit directly enters the bidirectional gear pump through the emergency lowering valve.

[0018] The purpose of the present application is also to provide a vehicle for people to go up, comprising a hydraulic system of the vehicle for people to go up as described in any of the above items.

[0019] Due to the adoption of the above scheme, this application has the following advantages:

[0020] 1. Through the linear change of the opening of the proportional directional valve, the flow priority valve can dynamically distribute the flow, reducing energy consumption; at the same time, it can prevent the hydraulic pump output flow from exceeding the actual demand, reduce the system heat, and extend the life of hydraulic parts;

[0021] 2. It can avoid unstable cylinder movement caused by insufficient flow (such as shaking of the lifting cylinder or sluggishness of the auxiliary cylinder) and improve the overall stability of the hydraulic system.

[0022] 3. Flow priority can also simplify operation and improve controllability. The operator does not need to manually adjust the flow distribution. The system automatically optimizes the flow distribution, reduces the difficulty of operation, and improves the controllability and operating efficiency of the forklift;

[0023] 4. By controlling the switching of the unloading solenoid valve on the unloading oil circuit between power on and power off, and controlling the auxiliary action oil circuit to be in the on working state, the excess flow of the oil limited valve can be directly and completely unloaded through the unloading oil circuit without the need to unload through the overflow valve, thus avoiding energy loss;

[0024] 5. The control knob controls the current size of the proportional control valve and the output power of the motor in a linked speed manner, combining motor speed regulation with proportional flow control to achieve precise control of the actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the hydraulic system oil circuit structure of this application;

[0026] Figure 2 A schematic diagram of the structure of a vehicle for people going up for this application;

[0027] Figure 3 A schematic diagram of the structural arrangement of the hydraulic system of the present application on a vehicle for people to travel on;

[0028] Figure 4 This is a schematic diagram of the hydraulic control valve group layout.

[0029] Reference numerals:

[0030] 1 bidirectional gear pump, 2 proportional directional valve, 3 flow priority valve, 41 first one-way valve, 42 second one-way valve, 5 lifting cylinder, 6 main gantry cylinder, 7 unloading solenoid valve, 8 damping hole, 9 overflow valve, 10 proportional flow valve, 11 emergency lowering valve, 12 lowering solenoid valve, 13 return oil back pressure valve, 14 return oil filter, 17 pump motor, 18 hydraulic control valve group. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below.

[0032] This embodiment provides a vehicle for people to go up, such as Figure 2 As shown, it mainly includes a gantry system and a hydraulic control system.

[0033] The gantry system includes a main gantry, a lifting platform slidingly arranged on the main gantry, a main gantry oil cylinder 6 for realizing the lifting of the gantry, and a lifting cylinder 5 for driving the lifting platform to lift. The lifting platform can be an operating platform or a fork. In addition to lifting, the lifting platform can also realize auxiliary actions such as horizontal movement, front and rear tilt adjustment, etc. by the hydraulic system and auxiliary action oil cylinder.

[0034] The hydraulic control system includes a lifting action oil circuit and an auxiliary action oil circuit connected to the gantry system, wherein the lifting action oil circuit is connected to the main gantry cylinder 6 and the lifting cylinder, and the lifting action control of the gantry lift platform is realized by controlling the hydraulic oil entering and exiting the main gantry cylinder 6 and the lifting cylinder; the auxiliary action oil circuit is connected to the auxiliary action oil volume, and the auxiliary action control of the vehicle is realized by controlling the hydraulic oil entering and exiting the auxiliary action cylinder.

[0035] like Figure 1 and Figure 3 As shown, the power structure of the hydraulic control system mainly includes a motor and a bidirectional gear pump 1. The motor in this embodiment refers to a pump motor 17, which drives the bidirectional gear pump 1 to deliver hydraulic oil in the hydraulic control system. The hydraulic control system also includes a hydraulic control valve group 18, such as Figure 4 As shown, multiple hydraulic control valves in the hydraulic control valve group 18 in this embodiment are concentrated on a valve group mounting seat. This arrangement facilitates the connection between the hydraulic pipeline and the hydraulic valve group in the hydraulic control system, and the connection relationship of each hydraulic control valve can be arranged on the valve group mounting seat in advance, which can improve the assembly efficiency and improve the structural compactness of the vehicle.

[0036] In the hydraulic oil circuit, the hydraulic control valve group 18 includes a proportional directional valve 2 and a flow priority valve 3; the proportional directional valve 2 switches between a small opening and a large opening, and the flow priority valve 3 switches between working in the left position and working in the right position; when the proportional directional valve 2 is in a small opening, the flow priority valve 3 works in the left position, the vehicle's lifting action oil circuit is connected, and the auxiliary action oil circuit is cut off; when the proportional directional valve 2 is in a large opening, the flow priority valve 3 works in the right position, the vehicle's auxiliary action oil circuit is connected, and the lifting action oil circuit is cut off. Figure 1 As shown, in this embodiment, the 5th and 6th ports of the flow priority valve 3 are the hydraulic oil input ends, and the 7th and 8th ports are the hydraulic oil output ends. In one working state, the bidirectional gear pump 1 is running, the proportional directional valve 2QN1 is opened slightly, the bidirectional gear pump 1 outputs hydraulic oil, most of the oil cannot pass through the proportional directional valve 2, the oil goes from position 1 to the flow priority valve 3, so that the oil generates a hydraulic control force pushing to the right from position 6, so that the flow priority valve 3 works in the left position, and the hydraulic oil is output from the 8th port of the flow priority valve 3 to the lifting action oil circuit, and the vehicle realizes the lifting action. In another working state, the bidirectional gear pump 1 is running, the proportional directional valve 2QN1 is opened widely, the bidirectional gear pump 1 outputs hydraulic oil, most of the oil passes through the proportional directional valve 2 to the flow priority valve 3, the oil generates a hydraulic control force pushing to the left from position 5, so that the flow priority valve 3 works in the right position, and the hydraulic oil is output from the 7th port of the flow priority valve 3 to the auxiliary action oil circuit, and the vehicle realizes the auxiliary action.

[0037] By cooperating with the above-mentioned proportional directional valve 2 and flow priority valve 3 to control the hydraulic oil to enter the lifting action oil circuit or the auxiliary action oil circuit, the flow priority valve 3 can dynamically distribute the flow through the linear change of the opening of the proportional directional valve 2, thereby reducing energy consumption; at the same time, it can prevent the hydraulic pump output flow from exceeding actual demand, reduce system heat generation, and extend the life of hydraulic components; and it can also prevent unstable cylinder action due to insufficient flow (such as shaking of the lifting cylinder or sluggishness of the auxiliary cylinder), thereby improving the overall stability of the hydraulic system.

[0038] In this embodiment, a relief solenoid valve 7 is provided on the unloading oil circuit before the flow priority valve 3 enters the vehicle lifting action oil circuit. When the flow priority valve 3 works in the right position, the passage connecting the said relief solenoid valve 7 to the oil return tank is opened, and the excess hydraulic oil passing through the flow priority valve 3 to the lifting oil circuit is directly returned through the relief solenoid valve 7. In this way, during the auxiliary action, the hydraulic oil passing through the flow priority valve 3 to the lifting action oil circuit can be completely unloaded. If there is no relief valve, the excess flow of the flow priority valve 3 can only overflow from the overflow valve 9, thus generating a large amount of heat and causing energy loss. Further, a pressure relief oil circuit directly connected to the output end of the unloading solenoid valve 7 is provided on the oil circuit between the outflow end of the proportional directional valve 2 and the inflow port of the flow priority valve 3 working in the right position, and a damping hole 8 is provided on the said pressure relief oil circuit. The damping hole 8 is provided to relieve pressure, which can ensure the unloading of the hydraulic control force on the right side of the flow priority valve 3, and the valve core can easily move to the right, so as to achieve smooth switching of the lifting action, and effectively improve the overall stability of the hydraulic system. Preferably, an oil return filter 14 is provided at the output end of the unloading oil circuit, so that the oil return from the unloading oil circuit is filtered and then returned to the oil tank, which can prevent impurities from entering and improve the NAS level of cleanliness of the entire system.

[0039] like Figure 1 As shown, a first one-way valve 41 is provided between the flow priority valve 3 and the lifting action oil circuit, and a second one-way valve 42 is provided between the flow priority valve 3 and the auxiliary action oil circuit. By providing the first one-way valve 41 and the second one-way valve 42, it is ensured that sufficient hydraulic oil is required to enter the corresponding action oil circuit, and precise control can be achieved. The direction from the first end to the second end of the first one-way valve 41 is the conduction direction, the input end of the unloading oil circuit is connected to the first end of the first one-way valve 41, and the output end of the unloading oil circuit is connected to the return oil tank; the input end of the return oil circuit of the lifting action oil circuit of the vehicle is connected to the second end of the first one-way valve 41, and the output end of the return oil circuit of the lifting action oil circuit is connected to the bidirectional gear pump 1. According to the above arrangement, the conduction direction of the first one-way valve can be used to match whether the hydraulic oil of the vehicle is returned from the unloading oil circuit or the return oil circuit under different working conditions, and the structure is simple.

[0040] The return oil circuit of the vehicle's lifting action oil circuit is provided with a proportional flow valve 10, a descending solenoid valve 12 and an oil return back pressure valve 13. When the vehicle is descending, the proportional flow valve 10 and the descending solenoid valve 12 are opened, and the hydraulic oil returning from the vehicle's lifting action oil circuit passes through the proportional flow valve 10, the descending solenoid valve 12 and the oil return back pressure valve 13 and enters the bidirectional gear pump 1. In actual working conditions, the high mast frequently descends without load. When descending, the large chambers of the full free lifting cylinder 5 and the main mast oil cylinder 6 are connected in series in pairs; the proportional flow valve 10QN2 is energized, and the proportional solenoid valve and pressure compensation valve inside it can control different descending speeds, and through the pressure compensation function, different load conditions can be guaranteed, and the speed is stable during the descent process to prevent the high mast from stalling and causing accidents when descending with heavy load; the descending solenoid valve 12QM2 is energized to achieve double protection for descent to prevent safety problems caused by the failure of the proportional flow valve 10.

[0041] According to the above arrangement, when the high mast is lowered, the oil in the large cylinder chambers of the main mast cylinder 6 and the lifting cylinder 5 passes through the proportional flow valve 10, the lowering solenoid valve 12 and the return oil back pressure valve 13, and enters the two-way gear pump 1, driving the two-way gear pump 1 to rotate in the opposite direction, and driving the motor to convert the pressure energy into electrical energy, thereby realizing the energy recovery function of the high mast load lowering. Preferably, it also includes an emergency return oil circuit, and an emergency lowering valve 11 is provided on the emergency return oil circuit. After the emergency lowering valve 11 is opened, the hydraulic oil returning from the vehicle's lifting action oil circuit directly passes through the emergency lowering valve 11 and enters the two-way gear pump 1. The emergency lowering valve 11 provides a safety mechanism for the vehicle to ensure that the lifting platform can be safely lowered from a high position when the system fails.

[0042] On the other hand, the vehicle also includes a control knob, which controls the current of the proportional directional valve 2 to achieve a linear change in the opening of the proportional directional valve; the control knob also performs linkage speed control on the output power of the motor. In this embodiment, the specific linkage method of the two is to preset the relationship between the current of the proportional directional valve 2 and the output power of the motor according to the matching performance of the required flow of the lifting cylinder 5 and the main mast oil cylinder 6 and the output flow of the bidirectional gear pump 1, and the control knob performs linkage control on the proportional directional valve 2 and the motor according to the preset relationship. Thus, the motor speed regulation is combined with the proportional flow control to achieve precise control of the actuator. Especially in heavy-load micro-operation conditions, the control knob is set to a small opening, and the handle can control the small displacement of the oil cylinder at a large angle, greatly improving the controllability.

[0043] Specifically, during the lifting action, the pump motor 17 outputs a constant flow rate, which is adjusted by the knob in the cab to control the current of the proportional directional valve 2QN1, thereby realizing a linear change in the valve opening. The oil passes through the bypass of the proportional directional valve 2 and then passes through the left position function of the flow priority valve 3. At the same time, the knob controls the motor speed in a linked manner, which can effectively improve the matching performance of the required flow of the full-free lifting cylinder 5 and the main mast cylinder 6 and the output flow of the bidirectional gear pump 1, thereby reducing the heat generated by flow redundancy.

[0044] During auxiliary action, the pump motor 17 outputs a constant flow rate, which is adjusted by the knob in the cab to control the current of the proportional directional valve 2QN1, thereby achieving a linear change in the valve opening, and the oil passes through the proportional directional valve 2 and the right position function of the flow priority valve 3; at the same time, the knob controls the motor speed in linkage, which can effectively improve the matching performance of the required flow of the auxiliary fork swing cylinder and the side shift cylinder and the output flow of the bidirectional gear pump 1, and reduce the heat generated by flow redundancy.

[0045] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A hydraulic system for a vehicle for people to go up, characterized in that: include: Motor, A bidirectional gear pump driven by the motor to deliver hydraulic oil to the hydraulic oil circuit in a forward or reverse direction; A hydraulic control valve group connected to the hydraulic oil circuit, the hydraulic control valve group includes a proportional directional valve and a flow priority valve; the proportional directional valve switches between a small opening and a large opening, and the flow priority valve switches between working in the left position and working in the right position; when the proportional directional valve is in a small opening, the flow priority valve works in the left position, the lifting action oil circuit of the vehicle is connected, and the auxiliary action oil circuit is cut off; when the proportional directional valve is in a large opening, the flow priority valve works in the right position, the auxiliary action oil circuit of the vehicle is connected, and the lifting action oil circuit is cut off; A unloading solenoid valve is provided on the unloading oil circuit before the flow priority valve enters the vehicle lifting action oil circuit. When the flow priority valve is in the right position, the passage connecting the unloading solenoid valve to the return oil tank is opened, and the excess hydraulic oil that passes through the flow priority valve to the lifting oil circuit is directly returned through the unloading solenoid valve.

2. The hydraulic system of a vehicle for people climbing up according to claim 1, characterized in that: The oil circuit between the outflow end of the proportional directional valve and the inflow port of the right-position working flow priority valve is provided with a pressure relief oil circuit directly connected to the output end of the unloading solenoid valve, and a damping hole is provided on the pressure relief oil circuit.

3. The hydraulic system of a vehicle for people climbing up according to claim 1, characterized in that: A first one-way valve is arranged between the flow priority valve and the lifting action oil circuit, and a second one-way valve is arranged between the flow priority valve and the auxiliary action oil circuit.

4. The hydraulic system of a vehicle for people traveling on foot according to claim 3, characterized in that: The direction from the first end to the second end of the second solenoid valve is the conduction direction, the input end of the unloading oil circuit is connected to the first end of the second solenoid valve, and the output end of the unloading oil circuit is connected to the return oil tank; the input end of the return oil circuit of the vehicle's lifting action oil circuit is connected to the second end of the second solenoid valve, and the output end of the return oil circuit of the lifting action oil circuit is connected to the bidirectional gear pump.

5. The hydraulic system of a vehicle for people climbing up according to claim 1, characterized in that: An oil return filter is provided at the output end of the unloading oil circuit.

6. The hydraulic system of a vehicle for people traveling on foot according to claim 1, characterized in that: It includes a control knob, which controls the current size of the proportional directional valve to achieve a linear change in the opening of the proportional directional valve; the control knob also performs linkage speed control on the output power of the motor.

7. The hydraulic system of a vehicle for people traveling on foot according to claim 6, characterized in that: According to the matching performance of the required flow of the lifting cylinder and the main mast cylinder and the output flow of the bidirectional gear pump, the relationship between the current size of the proportional directional valve and the output power of the motor is preset, and the control knob controls the proportional directional valve and the motor in linkage according to the preset relationship.

8. The hydraulic system of a vehicle for people traveling on foot according to claim 1, characterized in that: A proportional flow valve, a descending solenoid valve and a return oil back pressure valve are provided on the return oil circuit of the vehicle's lifting action oil circuit. When the vehicle is descending, the proportional flow valve and the descending solenoid valve are opened, and the hydraulic oil returning from the vehicle's lifting action oil circuit passes through the proportional flow valve, the descending solenoid valve and the return oil back pressure valve into the bidirectional gear pump.

9. The hydraulic system of a vehicle for people traveling on foot according to claim 6, characterized in that: It also includes an emergency oil return circuit, on which an emergency lowering valve is arranged, and the hydraulic oil returning from the vehicle's lifting action circuit directly enters the bidirectional gear pump through the emergency lowering valve.

10. A vehicle for people to go up, characterized in that: A hydraulic system comprising a human climbing vehicle as described in any one of claims 1-10.

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