A diverter valve, hydraulic system and engineering machinery

Abstract

The invention discloses a diverter valve and its hydraulic system and engineering machinery. The diverter valve comprises a throttle valve, a first hydraulic control valve, a second hydraulic control valve, a check valve, a sequence valve, a third hydraulic control valve and a shuttle valve. The oil inlet of the diverter valve is connected to the confluence port through the throttle valve and the check valve in sequence. The pressure before the throttle valve and the pressure after the throttle valve are respectively connected to the control chamber at one end of the second hydraulic control valve. The outlet end of the throttle valve is respectively connected to the oil return port T2 through the first hydraulic control valve and the third hydraulic control valve in a working position, which is used for unloading through the first hydraulic control valve and the third hydraulic control valve. The control chamber of the first hydraulic control valve is connected to the oil return port T3 through the second hydraulic control valve in the first working position. The control port c1 and the control port c2 are respectively connected to an inlet of the shuttle valve. The working port of the shuttle valve is connected to the control chamber of the first hydraulic control valve through the second hydraulic control valve in the second working position. The confluence port P2 is connected to the control end of the third hydraulic control valve through the sequence valve. The confluence and unloading of the oil inlet flow or the confluence port pressure are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery, and in particular relates to a diverter valve and a hydraulic system thereof, and engineering machinery. Background Art

[0002] At present, the power source of the hydraulic system adopts the internal combustion engine. If the metering pump is used as the power element, the system flow will change with the speed of the internal combustion engine, which has a huge impact on the performance of the hydraulic system, especially when the speed of the internal combustion engine is low, the efficiency of the hydraulic system decreases significantly. If the displacement of the metering pump is increased to ensure the sufficient system flow when the internal combustion engine is at a low speed, then when the internal combustion engine is at a high speed, the metering pump will provide a large amount of excess flow, or throttling or overflow, which will cause energy waste. At the same time, when the system pressure is high, the torque required by the large-displacement metering pump will also increase, affecting the output of the power source. Generally, there is more than one actuator in the hydraulic system, and the required flow of multiple actuators is different. When designing, it can only be based on the actuator with the maximum flow, which will cause the flow of the actuator with low required flow to be wasted, and the flow exceeding the demand may cause harm. To solve this contradiction, the technical solution currently used in the market is to use a variable pump to provide the corresponding flow according to the needs of the actuator, but the variable pump has a high cost and a complex system. Summary of the invention

[0003] Purpose: In order to overcome the deficiencies in the prior art, the present invention provides a diverter valve and its hydraulic system and engineering machinery. According to the flow change of the hydraulic system pump, the flow converging into the system is automatically adjusted to ensure the flow of different actuators in the system, thereby avoiding energy waste and eliminating the harm caused by excessive flow. At the same time, the system flow is adjusted according to the system pressure to avoid excessive torque required by pumps one and two, which affects the output of the power source.

[0004] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is:

[0005] In a first aspect, a diverter valve is provided, including a throttle valve, a first hydraulically controlled valve, a second hydraulically controlled valve, a one-way valve, a sequence valve, a third hydraulically controlled valve, and a shuttle valve, wherein the diverter valve is provided with a control port c1, a control port c2, a confluence port P2, an oil inlet P3, an oil return port T2, and an oil return port T3;

[0006] The oil inlet P3 of the diverter valve is connected to the confluence port P2 through the throttle valve and the one-way valve in sequence. The pressure before the throttle valve is connected to the control chamber at one end of the second hydraulic control valve, and the pressure after the throttle valve is connected to the control chamber at the other end of the second hydraulic control valve, which is used to control the valve core position of the second hydraulic control valve.

[0007] The outlet end of the throttle valve is connected to the oil return port T2 through the first hydraulic control valve in one of the working positions and the third hydraulic control valve in one of the working positions, respectively, for unloading through the first hydraulic control valve and the third hydraulic control valve; the control chamber of the first hydraulic control valve is connected to the oil return port T3 through the second hydraulic control valve in the first working position;

[0008] One of the control ports c1 and c2 is connected to an inlet of the shuttle valve, and the other of the control ports c1 and c2 is connected to another inlet of the shuttle valve; the working port of the shuttle valve is connected to the control chamber of the first hydraulic control valve through the second hydraulic control valve in the second working position, so as to control the valve core position of the first hydraulic control valve;

[0009] One end of the sequence valve is connected to the confluence port P2, and the other end is connected to the control end of the third hydraulic control valve, so as to control the valve core position of the third hydraulic control valve.

[0010] In some embodiments, the control port c1 of the diverter valve is connected to the lower inlet of the shuttle valve, the control port c2 is connected to the upper inlet of the shuttle valve, and the outlet of the throttle valve is connected to the oil return port T2 through the first hydraulic control valve in the right position and the third hydraulic control valve in the right position respectively;

[0011] When the flow rate of the oil inlet P3 does not exceed the set value, the control chamber of the first hydraulic control valve is connected to the oil return port T3 through the second hydraulic control valve in the upper position. The first hydraulic control valve is in the right position under the force of the return spring, and the flow rate of the oil inlet P3 cannot be unloaded through the first hydraulic control valve in the diverter valve, so that the flow rate of the oil inlet P3 flows to the confluence port P2 for merging;

[0012] When the flow rate of the oil inlet P3 exceeds the set value, the working port of the shuttle valve is connected to the control port of the first hydraulic control valve through the second hydraulic control valve in the lower position, the first hydraulic control valve moves left, and the flow rate of the oil inlet P3 is unloaded through the first hydraulic control valve in the diverter valve;

[0013] When the pressure at the confluence port P2 exceeds the preset value, the sequence valve opens, pushing the third hydraulic control valve to switch to the left position. The flow at the confluence port P2 is unloaded back to the hydraulic oil tank through the third hydraulic control valve, unloading the pressure at the confluence port P2.

[0014] In a second aspect, a hydraulic system is provided, including a hydraulic oil tank, a pump 1, a pump 2, a pilot valve, a multi-way valve, an actuator 1, an actuator 2 and the diverter valve; both the pump 1 and the pump 2 are quantitative pumps;

[0015] The pump 1 includes a front pump and a rear pump; the oil inlets of the front pump, the rear pump and the pump 2 are all connected to the hydraulic oil tank, the oil outlet of the front pump is connected to the oil inlet P1 of the multi-way valve and the confluence port P2 of the diverter valve, the oil outlet of the pump 2 is connected to the oil inlet P3 of the diverter valve, and the oil outlet of the rear pump is connected to the oil inlet P4 of the pilot valve; the control port a1 of the pilot valve is connected to the control port b1 of the multi-way valve and the control port c1 of the diverter valve, the control port a2 of the pilot valve is connected to the control port b2 of the multi-way valve and the control port c2 of the diverter valve, the control port a3 of the pilot valve is connected to the control port b3 of the multi-way valve, and the control port a4 of the pilot valve is connected to the control port b4 of the multi-way valve;

[0016] The working oil port A1 of the multi-way valve is connected to the rodless chamber oil port of the actuator one, the working oil port B1 of the multi-way valve is connected to the rod chamber oil port of the actuator one, the working oil port A2 of the multi-way valve is connected to the rodless chamber of the actuator two, and the working oil port B2 of the multi-way valve is connected to the rod chamber oil port of the actuator two;

[0017] The oil return port T1 of the multi-way valve and the oil return ports T2 and T3 of the diverter valve are connected to the hydraulic oil tank.

[0018] In some embodiments, the actuator 1 is a hydraulic cylinder.

[0019] In some embodiments, the second actuator is a hydraulic cylinder.

[0020] In some embodiments, the multi-way valve is a pilot-controlled multi-way valve.

[0021] In some embodiments, an overflow valve is also provided at the oil outlet of the rear pump, and the oil flows back to the hydraulic oil tank through the overflow port.

[0022] In a third aspect, the present invention further provides an engineering machinery comprising the above-mentioned hydraulic system.

[0023] Beneficial effects: The diverter valve and its hydraulic system and engineering machinery provided by the present invention add a pump 2. The diverter valve automatically adjusts the flow rate of the system according to the flow change of pump 2 and the operation of the actuator, so as to ensure that the actuator 1 always meets the large flow demand of the double pump confluence, and ensure the relative flow rate of the actuator 2 is stable. When the flow rate of pump 2 is large, pump 1 supplies oil and pump 2 is unloaded. When the flow rate of pump 2 is insufficient, the double pumps are confluent, which reduces energy waste and avoids the harm caused by large flow. When the system pressure exceeds a certain value, pump 2 is unloaded through the diverter valve to ensure that the torque required by pump 1 and pump 2 is controlled within a certain range without affecting the output of the power source. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a diverter valve according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of a hydraulic system according to an embodiment of the present invention;

[0026] Figure 3 It is the principle diagram of pump 1 in the embodiment;

[0027] In the figure: hydraulic oil tank 1, pump 1 2, pump 2 3, pilot valve 4, multi-way valve 5, diverter valve 6, actuator 1 7, actuator 2 8; front pump 21, rear pump 22, overflow valve 23; throttle valve 61, first hydraulic control valve 62, second hydraulic control valve 63, check valve 64, sequence valve 65, third hydraulic control valve 66, shuttle valve 67. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0030] Example 1

[0031] like Figure 1 As shown, a diverter valve includes a throttle valve 61, a first hydraulic control valve 62, a second hydraulic control valve 63, a check valve 64, a sequence valve 65, a third hydraulic control valve 66, and a shuttle valve 67. The diverter valve is provided with a control port c1, a control port c2, a confluence port P2, an oil inlet P3, an oil return port T2, and an oil return port T3;

[0032] The oil inlet P3 of the diverter valve 6 is connected to the confluence port P2 through the throttle valve 61 and the one-way valve 64 in sequence. The pressure before the throttle valve 61 is connected to the control chamber at one end of the second hydraulic control valve 63, and the pressure after the throttle valve 61 is connected to the control chamber at the other end of the second hydraulic control valve 63, which is used to control the valve core position of the second hydraulic control valve 63;

[0033] The outlet end of the throttle valve 61 is connected to the oil return port T2 through the first hydraulic control valve 62 in one of the working positions and the third hydraulic control valve 66 in one of the working positions, respectively, for unloading through the first hydraulic control valve 62 and the third hydraulic control valve 66; the control chamber of the first hydraulic control valve 62 is connected to the oil return port T3 through the second hydraulic control valve 63 in the first working position;

[0034] One of the control ports c1 and c2 is connected to an inlet of the shuttle valve 67, and the other of the control ports c1 and c2 is connected to another inlet of the shuttle valve 67; the working port of the shuttle valve 67 is connected to the control chamber of the first hydraulic control valve 62 through the second hydraulic control valve 63 in the second working position, so as to control the valve core position of the first hydraulic control valve 62;

[0035] One end of the sequence valve 65 is connected to the confluence port P2 , and the other end is connected to the control end of the third hydraulically controlled valve 66 , so as to control the valve core position of the third hydraulically controlled valve 66 .

[0036] In some embodiments, Figure 1 As shown, the control port c1 of the diverter valve 6 is connected to the lower inlet of the shuttle valve 67, the control port c2 is connected to the upper inlet of the shuttle valve 67, and the outlet end of the throttle valve 61 is connected to the oil return port T2 through the first hydraulic control valve 62 in the right position and the third hydraulic control valve 66 in the right position respectively;

[0037] When the flow rate of the oil inlet P3 does not exceed the set value, the control chamber of the first hydraulic control valve 62 is connected to the oil return port T3 through the second hydraulic control valve 63 in the upper position. The first hydraulic control valve 62 is in the right position under the force of the return spring, and the flow rate of the oil inlet P3 cannot be unloaded through the first hydraulic control valve 62 in the diverter valve 6, so that the flow rate of the oil inlet P3 flows to the confluence port P2 for merging;

[0038] When the flow rate of the oil inlet P3 exceeds the set value, the working port of the shuttle valve 67 is connected to the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63 in the lower position, the first hydraulic control valve 62 moves left, and the flow rate of the oil inlet P3 is unloaded through the first hydraulic control valve 62 in the diverter valve 6;

[0039] When the pressure at the confluence port P2 exceeds a preset value, the sequence valve 65 opens, pushing the third hydraulic control valve 66 to switch to the left position, and the flow at the confluence port P2 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, unloading the pressure at the confluence port P2.

[0040] Example 2

[0041] like Figure 2As shown, a hydraulic system includes a hydraulic oil tank 1, a pump 1 2, a pump 2 3, a pilot valve 4, a multi-way valve 5, an actuator 1 7, an actuator 2 8 and the above-mentioned diverter valve 6; the pump 1 2 and the pump 2 3 are both quantitative pumps;

[0042] like Figure 3 As shown, the pump 1 2 includes a front pump 21, a rear pump 22, and a relief valve 23; the oil inlets of the front pump 21, the rear pump 22, and the pump 2 3 are all connected to the hydraulic oil tank 1, the oil outlet of the front pump 21 is connected to the oil inlet P1 of the multi-way valve 5 and the confluence port P2 of the diverter valve 6, the oil outlet of the pump 2 3 is connected to the oil inlet P3 of the diverter valve 6, and the oil outlet of the rear pump 22 is connected to the oil inlet P4 of the pilot valve 4; the control port a1 of the pilot valve 4 is connected to the control port b1 of the multi-way valve 5 and the control port c1 of the diverter valve 6, the control port a2 of the pilot valve 4 is connected to the control port b2 of the multi-way valve 5 and the control port c2 of the diverter valve 6, the control port a3 of the pilot valve 4 is connected to the control port b3 of the multi-way valve 5, and the control port a4 of the pilot valve 4 is connected to the control port b4 of the multi-way valve 5;

[0043] The working oil port A1 of the multi-way valve 5 is connected to the rodless chamber oil port of the actuator 1 7, the working oil port B1 of the multi-way valve 5 is connected to the rod chamber oil port of the actuator 1 7, the working oil port A2 of the multi-way valve 5 is connected to the rodless chamber of the actuator 2 8, and the working oil port B2 of the multi-way valve 5 is connected to the rod chamber oil port of the actuator 2 8;

[0044] The oil return port T1 of the multi-way valve 5 and the oil return ports T2 and T3 of the diverter valve 6 are connected to the hydraulic oil tank 1 .

[0045] In some embodiments, actuator 1 and actuator 2 include but are not limited to hydraulic cylinders.

[0046] In some embodiments, the multi-way valve 5 is a pilot-controlled multi-way valve.

[0047] In some embodiments, Figure 3 As shown, an overflow valve 23 is also provided at the oil outlet of the rear pump 22, and the oil flows back to the hydraulic oil tank 1 through the overflow port.

[0048] The flow of the pump 2 3 passes through the diverter valve 6. According to the different flow rates of the pump 2 3 and different operating requirements, the diverter valve 6 is controlled to merge the flow into the system.

[0049] Based on the above structure, the oil inlets of pump 1 2 and pump 2 3 can be connected to the hydraulic oil tank 1 respectively, or the oil inlets of the two pumps can be connected and then connected to the hydraulic oil tank 1. Pump 1 2, pump 2 3 and hydraulic oil tank 1 can be connected directly or through a filter element to filter impurities in the hydraulic oil.

[0050] The working process of the present invention is as follows: when there is no operating action in the system, there is no pressure in the control ports of the pilot valve 4, the multi-way valve 5 and the diverter valve 6, the valve core of the multi-way valve 5 is in the middle position, the flow of pump 1 2 flows in through the oil port P1 of the multi-way valve 5, and directly returns to the oil tank from the oil return port T1 of the multi-way valve 5; the flow of pump 2 3 flows from the oil port P3 of the diverter valve 6 through the internal one-way valve 64, and then flows in through the oil port P1 of the multi-way valve 5, and also directly returns to the oil tank from the oil return port T1 of the multi-way valve 5.

[0051] When the system operates the actuator 2 8 to extend, the pilot valve 4 connects the oil inlet P4 and the control port a2, the oil at the outlet of the rear pump 22 in the pump 1 2 enters the control port b2 of the multi-way valve 5 through the pilot valve 4, the actuator 2 8 in the multi-way valve 5 controls the valve core to move left, and the excess oil at the outlet of the rear pump 22 overflows back to the hydraulic oil tank 1 from the overflow valve 23, the oil at the outlet of the pump 2 3 passes through the diverter valve 6, merges with the front pump 21 of the pump 1 2, and then enters the rodless chamber of the actuator 2 8 through the multi-way valve 5, and the actuator 2 8 extends. When the operating element 2 8 is extended, the pressure at the control port a2 of the pilot valve 4 is transmitted to the control port c2 of the diverter valve 6 at the same time. The shuttle valve 67 in the diverter valve 6 opens in the upper position and closes in the lower position. The pressure at the control port c2 enters the oil inlet of the second hydraulic control valve 63. The oil at the outlet of the pump 2 3 generates pressure loss when flowing through the throttle valve 61 in the diverter valve 6. The pressure loss is proportional to the flow rate of the pump 2 3. The pressure before the throttle valve 61 is connected to the control chamber at the lower end of the second hydraulic control valve 63, and the pressure after the throttle valve 61 is connected to the control chamber at the upper end of the second hydraulic control valve 63. When the flow rate of pump 23 is small, the pressure difference at both ends of the throttle valve 61 is not enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 is in the upper position, the control chamber of the first hydraulic control valve 62 is connected to the hydraulic oil tank 1 through the second hydraulic control valve 63, the first hydraulic control valve 62 is in the right position under the return spring force, and the pump 23 cannot be unloaded through the first hydraulic control valve 62 in the diverter valve 6, so that the double pumps merge and the large flow is supplied to the actuator 28. When the flow rate of pump 23 exceeds a certain value, the pressure at both ends of the throttle valve 61 is enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 is in the lower position, the pressure of the diverter valve control port c2 is connected to the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63, the first hydraulic control valve 62 moves to the left, and the pump 23 is unloaded through the first hydraulic control valve 62 in the diverter valve 6, so as to realize the unloading of the pump 23. As the load of actuator 2 8 changes, when the system pressure is higher than a certain value, the sequence valve 65 in the diverter valve 6 opens, pushing the third hydraulic control valve 66 to switch to the left position, and pump 2 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66. When the system high pressure is achieved, pump 2 3 is unloaded, and the required torque of pump 1 2 and pump 2 3 is controlled to be below a certain value.

[0052] When the system operates the actuator 2 8 to be retracted, the pilot valve 4 connects the oil inlet P4 and the control port a1, the oil at the outlet of the rear pump 22 in the pump 1 2 enters the control port b1 of the multi-way valve 5 through the pilot valve 4, the actuator 2 8 in the multi-way valve 5 controls the valve core to move right, and the excess oil at the outlet of the rear pump 22 overflows back to the hydraulic oil tank 1 from the overflow valve 23, the oil at the outlet of the pump 2 3 passes through the diverter valve 6, merges with the pump 1 2, and then enters the rod chamber of the actuator 2 8 through the multi-way valve 5, and the actuator 2 8 is retracted. When the actuator 2 8 is retracted, the pressure of the control port a1 of the pilot valve 4 is transmitted to the control port c1 of the diverter valve 6 at the same time. The shuttle valve 67 in the diverter valve 6 opens in the lower position and closes in the upper position. The pressure of the control port c1 enters the oil inlet of the second hydraulic control valve 63. The oil at the outlet of the pump 2 3 generates pressure loss when flowing through the throttle valve 61 in the diverter valve 6. The pressure loss is proportional to the flow of the pump 2 3. The pressure before the throttle valve 61 is connected to the control chamber at the lower end of the second hydraulic control valve 63, and the pressure after the throttle valve 61 is connected to the control chamber at the upper end of the hydraulic control valve. When the flow of the pump 2 3 is small, the pressure difference between the two ends of the throttle valve 61 is not enough to overcome the return spring force of the second hydraulic control valve 63. The second hydraulic control valve 63 is in the upper position, and the control chamber of the first hydraulic control valve 62 is connected to the hydraulic oil tank 1 through the second hydraulic control valve 63. The first hydraulic control valve 62 is in the right position under the return spring force. The pump 2 3 cannot be unloaded through the first hydraulic control valve 62 in the diverter valve 6, so that the double pumps merge and a large flow is supplied to the actuator 2 8. When the flow of pump 23 exceeds a certain value, the pressure at both ends of the throttle valve 61 is sufficient to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 is in the lower position, the pressure of the diverter valve control port c1 is connected to the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63, the first hydraulic control valve 62 moves left, and pump 23 is unloaded through the first hydraulic control valve 62 in the diverter valve 6, realizing the unloading of pump 23. As the load of actuator 28 changes, when the system pressure is higher than a certain value, the sequence valve 65 in the diverter valve 6 opens, pushing the third hydraulic control valve 66 to switch to the left position, and pump 23 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66. When the system high pressure is achieved, pump 23 is unloaded, and the required torque of pump 12 and pump 23 is controlled below a certain value.

[0053] When the system operates the actuator 17 to extend, the pilot valve 4 connects the oil inlet port P4 and the control port a4, the oil at the outlet of the rear pump 22 in the pump 12 enters the control port b4 of the multi-way valve 5 through the pilot valve 4, the actuator 17 in the multi-way valve 5 controls the valve core to move left, the excess oil at the outlet of the rear pump 22 overflows from the overflow valve 23 back to the hydraulic oil tank 1, the oil at the outlet of the pump 23 passes through the diverter valve 6, merges with the pump 2, and then enters the rodless chamber of the actuator 17 through the multi-way valve 5, and the actuator 17 extends. When the actuator 17 is extended, the control ports a1 and a2 of the pilot valve 4 are both pressure-free, so the control ports c1 and c2 of the diverter valve 6 are also pressure-free. No matter how much the flow of the pump 23 is, the second hydraulic control valve 63 in the diverter valve 6 is in any position, the first hydraulic control valve 62 is always in the right position, and the pump 23 cannot be unloaded through the first hydraulic control valve 62 in the diverter valve 6, so that the double pumps merge and a large flow is supplied to the actuator 17. As the load of actuator 1 7 changes, when the system pressure is higher than a certain value, the sequence valve 65 in the diverter valve 6 opens, pushing the third hydraulic control valve 66 to switch to the left position, and pump 2 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66. When the system high pressure is achieved, pump 2 3 is unloaded, and the required torque of pump 1 2 and pump 2 3 is controlled below a certain value.

[0054] When the system operates the actuator 17 to retract, the pilot valve 4 connects the oil inlet P4 and the control port a3, the oil at the outlet of the rear pump 22 in the pump 12 enters the control port b3 of the multi-way valve 5 through the pilot valve 4, the actuator 17 in the multi-way valve 5 controls the valve core to move right, the excess oil at the outlet of the rear pump 22 overflows from the overflow valve 23 back to the hydraulic oil tank 1, the oil at the outlet of the pump 23 passes through the diverter valve 6, merges with the pump 2, and then enters the rod chamber of the actuator 17 through the multi-way valve 5, and the actuator 17. When the actuator 17 is retracted, the control ports a1 and a2 of the pilot valve 4 are both pressure-free, so the control ports c1 and c2 of the diverter valve 6 are also pressure-free, no matter how much the flow of the pump 23 is, causing the second hydraulic control valve 63 in the diverter valve 6 to be in any position, the first hydraulic control valve 62 is always in the right position, the pump 23 cannot be unloaded through the first hydraulic control valve 62 in the diverter valve 6, and the double pumps are merged, and a large flow is supplied to the actuator 17. As the load of actuator 1 7 changes, when the system pressure is higher than a certain value, the sequence valve 65 in the diverter valve 6 opens, pushing the third hydraulic control valve 66 to switch to the left position, and pump 2 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66. When the system high pressure is achieved, pump 2 3 is unloaded, and the required torque of pump 1 2 and pump 2 3 is controlled below a certain value.

[0055] During the operation of the system, when the system pressure is higher than the set value of the multi-way valve 5 safety valve, the multi-way valve 5 safety valve opens, and the flow of pump 2 is unloaded through the multi-way valve 5 safety valve.

[0056] Example 3

[0057] On the other hand, there is also provided an engineering machine comprising the above-mentioned hydraulic system.

[0058] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0059] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A diverter valve, characterized in that: It includes a throttle valve, a first hydraulic control valve, a second hydraulic control valve, a one-way valve, a sequence valve, a third hydraulic control valve, and a shuttle valve. The diverter valve is provided with a control port c1, a control port c2, a confluence port P2, an oil inlet P3, an oil return port T2, and an oil return port T3; The oil inlet P3 of the diverter valve is connected to the confluence port P2 through the throttle valve and the one-way valve in sequence. The pressure before the throttle valve is connected to the control chamber at one end of the second hydraulic control valve, and the pressure after the throttle valve is connected to the control chamber at the other end of the second hydraulic control valve, which is used to control the valve core position of the second hydraulic control valve. The outlet end of the throttle valve is connected to the oil return port T2 through the first hydraulic control valve in one of the working positions and the third hydraulic control valve in one of the working positions, respectively, for unloading through the first hydraulic control valve and the third hydraulic control valve; the control chamber of the first hydraulic control valve is connected to the oil return port T3 through the second hydraulic control valve in the first working position; One of the control ports c1 and c2 is connected to an inlet of the shuttle valve, and the other of the control ports c1 and c2 is connected to another inlet of the shuttle valve; the working port of the shuttle valve is connected to the control chamber of the first hydraulic control valve through the second hydraulic control valve in the second working position, so as to control the valve core position of the first hydraulic control valve; One end of the sequence valve is connected to the confluence port P2, and the other end is connected to the control end of the third hydraulic control valve, so as to control the valve core position of the third hydraulic control valve.

2. The diverter valve according to claim 1, characterized in that: The control port c1 of the diverter valve is connected to the lower inlet of the shuttle valve, the control port c2 is connected to the upper inlet of the shuttle valve, and the outlet of the throttle valve is connected to the oil return port T2 through the first hydraulic control valve in the right position and the third hydraulic control valve in the right position respectively; When the flow rate of the oil inlet P3 does not exceed the set value, the control chamber of the first hydraulic control valve is connected to the oil return port T3 through the second hydraulic control valve in the upper position. The first hydraulic control valve is in the right position under the force of the return spring, and the flow rate of the oil inlet P3 cannot be unloaded through the first hydraulic control valve in the diverter valve, so that the flow rate of the oil inlet P3 flows to the confluence port P2 for merging; When the flow rate of the oil inlet P3 exceeds the set value, the working port of the shuttle valve is connected to the control port of the first hydraulic control valve through the second hydraulic control valve in the lower position, the first hydraulic control valve moves left, and the flow rate of the oil inlet P3 is unloaded through the first hydraulic control valve in the diverter valve; When the pressure at the confluence port P2 exceeds the preset value, the sequence valve opens, pushing the third hydraulic control valve to switch to the left position. The flow at the confluence port P2 is unloaded back to the hydraulic oil tank through the third hydraulic control valve, unloading the pressure at the confluence port P2.

3. A hydraulic system, characterized in that: It comprises a hydraulic oil tank, a pump 1, a pump 2, a pilot valve, a multi-way valve, an actuator 1, an actuator 2 and a diverter valve as claimed in claim 1 or 2; the pump 1 and the pump 2 are both quantitative pumps; The pump 1 includes a front pump and a rear pump; the oil inlets of the front pump, the rear pump and the pump 2 are all connected to the hydraulic oil tank, the oil outlet of the front pump is connected to the oil inlet P1 of the multi-way valve and the confluence port P2 of the diverter valve, the oil outlet of the pump 2 is connected to the oil inlet P3 of the diverter valve, and the oil outlet of the rear pump is connected to the oil inlet P4 of the pilot valve; the control port a1 of the pilot valve is connected to the control port b1 of the multi-way valve and the control port c1 of the diverter valve, the control port a2 of the pilot valve is connected to the control port b2 of the multi-way valve and the control port c2 of the diverter valve, the control port a3 of the pilot valve is connected to the control port b3 of the multi-way valve, and the control port a4 of the pilot valve is connected to the control port b4 of the multi-way valve; The working oil port A1 of the multi-way valve is connected to the rodless chamber oil port of the actuator one, the working oil port B1 of the multi-way valve is connected to the rod chamber oil port of the actuator one, the working oil port A2 of the multi-way valve is connected to the rodless chamber of the actuator two, and the working oil port B2 of the multi-way valve is connected to the rod chamber oil port of the actuator two; The oil return port T1 of the multi-way valve and the oil return ports T2 and T3 of the diverter valve are connected to the hydraulic oil tank.

4. The hydraulic system according to claim 3, characterized in that: The first actuator is a hydraulic cylinder.

5. The hydraulic system according to claim 3, characterized in that: The second actuator is a hydraulic cylinder.

6. The hydraulic system according to claim 3, characterized in that: The multi-way valve is a pilot-controlled multi-way valve.

7. The hydraulic system according to claim 3, characterized in that: An overflow valve is also provided at the oil outlet of the rear pump, and the oil flows back to the hydraulic oil tank through the overflow port.

8. An engineering machine, characterized in that: Comprising a hydraulic system as described in any one of claims 3-7.

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