Oil drain valve, energy storage device, hydraulic system and work machine

Abstract

The present invention relates to the technical field of hydraulic systems, and provides an oil drain valve, an energy storage device, a hydraulic system and a working machine. The oil drain valve includes a valve body, a valve core and an elastic element. The valve body is provided with a first oil port and a second oil port. The valve core communicates with the first oil port and the second oil port, and the valve core can move in the valve body to switch the valve core between a first working position and a second working position. An elastic element is provided between the first end of the valve core and the valve body. The first end of the valve core communicates with the first oil port, and the second end of the valve core communicates with the second oil port. When the flow direction of the hydraulic oil in the oil drain valve is from the first oil port to the second oil port, the valve core can be switched from the second working position to the first working position under the action of the elastic element. When the flow direction of the hydraulic oil in the oil drain valve is from the second oil port to the first oil port, the valve core can compress the elastic element and switch from the first working position to the second working position. The flow rate of the oil drain valve when the valve core is in the second working position is less than the flow rate when the valve core is in the first working position.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and particularly to an oil drain valve, an energy storage device, a hydraulic system and a working machine. Background Art

[0002] Currently, in some hydraulic systems, an accumulator is usually provided to store or recover the hydraulic energy in the hydraulic system and release it when needed to achieve the purpose of energy saving.

[0003] For example, during the operation of a concrete pumping device, a set of hydraulic cylinders in the hydraulic system drive an S-valve to reciprocate in a hopper to convey the concrete in the hopper through a delivery cylinder and into a concrete pumping pipe, realizing the concrete conveying function. Among them, an accumulator is provided on the oil inlet circuit of the hydraulic cylinder to collect hydraulic energy when the accumulator is being filled with oil and supply hydraulic oil to the hydraulic cylinder when the accumulator is discharging oil.

[0004] However, in the related prior art, during the oil discharge process of the accumulator in the hydraulic system, the flow rate of the discharged hydraulic oil is not controlled. At the end of the cylinder stroke, the piston usually stops under the action of a rigid impact force, which is likely to damage the cylinder. Summary of the Invention

[0005] The present invention provides an oil drain valve, an energy storage device, a hydraulic system and a working machine to solve the problem that the accumulator in the hydraulic system of the prior art is likely to cause impact damage to the cylinder during the oil discharge process.

[0006] The present invention provides an oil drain valve, including a valve body, a valve core and an elastic element. The valve body is provided with a first oil port and a second oil port. The valve core is arranged between the first oil port and the second oil port and the valve core communicates with the first oil port and the second oil port. The valve core can move in the valve body to switch between a first working position and a second working position; an elastic element is arranged between the first end of the valve core and the valve body. The first end of the valve core is communicated with the first oil port, and the second end of the valve core is communicated with the second oil port;

[0007] When the hydraulic oil flow direction in the oil drain valve is from the first oil port to the second oil port, the valve core can switch from the second working position to the first working position under the action of the elastic element;

[0008] When the hydraulic oil flow direction in the oil drain valve is from the second oil port to the first oil port, the valve core can compress the elastic element and switch from the first working position to the second working position; the flow rate of the oil drain valve when the valve core works in the second working position is less than the flow rate when the valve core works in the first working position.

[0009] According to the present invention, an oil drain valve is provided. When the valve core works in the first working position and the second working position, the elastic element is in a compressed state, and the elastic force of the elastic element when the valve core works in the first working position is less than the elastic force of the elastic element when the valve core works in the second working position.

[0010] According to the present invention, an oil drain valve is provided. A limiting member is provided on the valve body. When the valve core works in the first working position, the limiting member prevents the valve core from moving away from the second working position.

[0011] According to the present invention, an oil drain valve is provided. An oil passage is provided in the valve body. A first back cavity is formed between the first end of the valve core and the valve body. The elastic element is arranged in the first back cavity. The oil passage communicates with the first back cavity and the first oil port to form a first feedback oil passage;

[0012] A cavity is provided at the second end of the valve core. The cavity communicates with the second oil port. A first oil hole is provided on the side wall of the cavity. The cavity communicates with the first oil port through the first oil hole; the opening degree of the first oil hole when the valve core works in the first working position is greater than the opening degree of the first oil hole when the valve core works in the second working position.

[0013] According to the present invention, an oil drain valve is further provided with a damping element. The damping element is arranged on the first feedback oil passage.

[0014] According to the present invention, the damping element is any one of a damping hole, a damper and an electronically controlled proportional flow valve.

[0015] According to the present invention, the damper is an adjustable damper.

[0016] According to the present invention, an oil drain valve is provided. The valve body includes a valve seat and a valve sleeve. The first oil port and the second oil port are both arranged on the valve seat. The valve seat is provided with a valve core cavity. The valve sleeve is fixed in the valve core cavity. The valve core is slidably arranged in the valve sleeve; a second oil hole is provided on the side wall of the valve sleeve. The second oil hole communicates with the first oil port and the first oil hole.

[0017] According to the present invention, the first back cavity is formed between the first end of the valve core and the first end of the valve sleeve. A damping hole is provided on the valve sleeve. The damping hole communicates with the first back cavity and the oil passage.

[0018] According to the present invention, an oil drain valve is provided. A first annular flow guide groove is provided on the inner side surface of the valve core cavity, and a second annular flow guide groove is provided on the inner side surface of the valve sleeve. The first oil port, the first annular flow guide groove, the second oil hole, the second annular flow guide groove, and the first oil hole are communicated in sequence.

[0019] The first oil hole includes a plurality of first through holes distributed along the circumferential direction of the valve core on the side wall of the cavity, and the second oil hole includes a plurality of second through holes distributed along the circumferential direction of the valve sleeve on the side wall of the valve sleeve.

[0020] According to the present invention, an oil drain valve is provided. The first oil hole includes a plurality of first through holes distributed along the axial direction of the valve core on the side wall of the cavity, and the aperture of the first through hole near the second end of the valve core is smaller than the aperture of the first through hole far from the second end of the valve core.

[0021] According to the present invention, an oil drain valve is provided. The elastic element is a return spring.

[0022] The present invention also provides an energy storage device, including an accumulator and any one of the above oil drain valves. The oil drain valve is installed at the oil outlet of the accumulator, and the oil outlet of the accumulator is communicated with the second oil port.

[0023] The present invention also provides a hydraulic system, including an oil pump, an actuating element, an accumulator, and any one of the above oil drain valves. The first oil port is respectively communicated with the oil outlet of the oil pump and the working oil port of the actuating element, and the second oil port is communicated with the oil outlet of the accumulator; or, the hydraulic system includes an oil pump, an actuating element, and the above energy storage device.

[0024] The present invention also provides a working machine, including the above hydraulic system.

[0025] The oil drain valve, energy storage device, hydraulic system, and working machine provided by the present invention connect the first oil port and the second oil port on the valve body through the valve core, form a first feedback oil path by connecting the first end of the valve core with the first oil port, form a second feedback oil path by connecting the second end of the valve core with the second oil port, and arrange an elastic element between the first end of the valve core and the valve body, so that when the flow direction of the hydraulic oil in the oil drain valve changes, the automatic switching of the working position of the valve core can be realized, and the flow rate of the hydraulic oil flowing through the oil drain valve is changed by setting the flow rate of different working positions, realizing the automatic control of its output flow rate. When the second oil port of the oil drain valve is communicated with the oil outlet of the accumulator for use, when the accumulator switches from oil filling to oil draining, the oil draining flow rate of the oil drain valve can be reduced by automatically switching the working position, preventing the actuating element from being damaged due to rigid impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is one of the schematic diagrams of the working principle of the oil drain valve provided by the present invention;

[0028] Figure 2 It is another schematic diagram of the working principle of the oil drain valve provided by the present invention;

[0029] Figure 3 It is the third schematic diagram of the working principle of the oil drain valve provided by the present invention;

[0030] Figure 4 It is one of the structural schematic diagrams of the oil drain valve provided by the present invention;

[0031] Figure 5 It is another structural schematic diagram of the oil drain valve provided by the present invention;

[0032] Reference numerals:

[0033] 100, oil drain valve; 1, valve body; 11, first oil port;

[0034] 12, second oil port; 13, spool cavity; 14, oil passage;

[0035] 15, valve seat; 16, valve sleeve; 161, damping hole;

[0036] 162, second oil hole; 163, second annular diversion groove; 17, buffer cavity;

[0037] 18, first annular diversion groove; 2, spool; 21, cavity;

[0038] 211, first oil hole; 3, elastic element; 4, first feedback oil passage;

[0039] 5, second feedback oil passage; 6, damping element; 200, accumulator. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts fall within the scope of protection of the present invention.

[0041] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "first" and "second" are used for numbering product components for clear illustration and do not represent any substantial difference. The directions of "left" and "right" are subject to the directions shown in the drawings. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The following Figures 1 to 5 describes the oil drain valve and energy storage device of the present invention.

[0044] As Figure 1 shown is one of the schematic diagrams of the working principle of the oil drain valve provided by the present invention, and as Figure 2 shown is another schematic diagram of the working principle of the oil drain valve provided by the present invention. As Figure 4 shown is one of the structural diagrams of the oil drain valve provided by the present invention, and as Figure 5 shown is another structural diagram of the oil drain valve provided by the present invention.

[0045] The oil drain valve 100 provided by the embodiments of the present invention includes a valve body 1, a valve core 2, and an elastic element 3. The valve body 1 is provided with a first oil port 11 and a second oil port 12. A valve core 2 is provided between the first oil port 11 and the second oil port 12, and the valve core 2 communicates with the first oil port 11 and the second oil port 12. The valve core 2 can move in the valve body 1 to switch the valve core 2 between a first working position and a second working position. An elastic element 3 is provided between the first end of the valve core 2 and the valve body 1. The first end of the valve core 2 communicates with the first oil port 11, and the second end of the valve core 2 communicates with the second oil port 12.

[0046] Figure 1 and Figure 4 show the state of the oil drain valve 100 when the valve core 2 is in the first working position, Figure 2 and Figure 5Shown is the state of the oil drain valve 100 when the valve core 2 is working in the second working position. When the hydraulic oil flow in the oil drain valve 100 is from the first oil port 11 to the second oil port 12, the valve core 2 can be switched from the second working position to the first working position under the action of the elastic element 3. When the hydraulic oil flow in the oil drain valve 100 is from the second oil port 12 to the first oil port 11, the valve core 2 can compress the elastic element 3 and be switched from the first working position to the second working position. The flow rate of the oil drain valve 100 when the valve core 2 is working in the second working position is less than the flow rate when the valve core 2 is working in the first working position.

[0047] Wherein, a cavity formed between the first end of the valve core 2 and the valve body 1 is communicated with the first oil port 11 to form a first feedback oil circuit 4. A cavity formed between the second end of the valve core 2 and the valve body 1 is communicated with the second oil port 12 to form a second feedback oil circuit 5. The elastic element 3 is arranged in the cavity formed between the first end of the valve core 2 and the valve body 1.

[0048] The oil drain valve provided by the embodiment of the present invention can be installed at the oil outlet of the accumulator 200, so that the oil outlet of the accumulator 200 is connected to the oil inlet of the actuator through the oil drain valve 100. In use, the second oil port 12 is used to connect to the oil outlet of the accumulator 200, and the first oil port 11 is used to connect to the working oil port of the actuator and the oil outlet of the oil pump. The charging and discharging of the accumulator 200 both pass through the oil drain valve 100. When charging, the oil pump pumps hydraulic oil to the accumulator 200 for energy storage. When discharging, the accumulator 200 supplies hydraulic energy to the actuator, and the oil drain valve 100 controls the hydraulic oil output volume of the accumulator 200.

[0049] As Figure 1 and Figure 4 shown, when the hydraulic oil flow in the oil drain valve 100 is from the first oil port 11 to the second oil port 12, that is, the first oil port 11 is used as the oil inlet and the second oil port 12 is used as the oil outlet, the valve core 2 works in the first working position, and the oil drain valve 100 is in the charging state to charge the accumulator 200.

[0050] As Figure 2 and Figure 5 shown, when the hydraulic oil flow in the oil drain valve 100 is switched from the first oil port 11 to the second oil port 12 to the second oil port 12 to the first oil port 11, that is, the second oil port 12 is switched to be the oil inlet and the first oil port 11 is switched to be the oil outlet, the oil drain valve 100 is switched from the charging state to the discharging state, and the valve core 2 can be switched from the first working position to the second working position, so that the flow rate of the hydraulic oil decreases.

[0051] Specifically, when the oil drain valve 100 is in a stable oil filling state, the valve core 2 operates in the first working position. At this time, the hydraulic pressure of the hydraulic oil in the first feedback oil circuit 4 on the first end of the valve core 2 is equal to the hydraulic pressure of the hydraulic oil in the second feedback oil circuit 5 on the second end of the valve core 2. Usually, there is also a pressure holding stage after the accumulator 200 is filled with oil. In the pressure holding state, the hydraulic pressures on both ends of the valve core 2 are also equal. When the oil drain valve 100 is in the oil filling state and the pressure holding state, the elastic element 3 exerts a leftward force on the first end of the valve core 2 to keep it operating in the first working position.

[0052] When the oil drain valve 100 switches from the oil filling state to the oil draining state, due to the change in the flow direction of the hydraulic oil, the acting force of the hydraulic oil in the first feedback oil circuit 4 on the second end of the valve core 2 is greater than the acting force of the hydraulic oil in the second feedback oil circuit 5 on the first end of the valve core 2, thereby pushing the valve core 2 to move to switch to the second working position, reducing the output flow rate of the oil drain valve 100.

[0053] When the valve core 2 operates in the second working position, when the flow direction of the hydraulic oil in the oil drain valve 100 switches from the second oil port 12 to the first oil port 11 to the first oil port 11 to the second oil port 12, the oil drain valve 100 switches from the oil draining state to the oil filling state. At this time, due to the change in the flow direction of the hydraulic oil, the acting force of the hydraulic oil in the first feedback oil circuit 4 on the first end of the valve core 2 is greater than the acting force of the hydraulic oil in the second feedback oil circuit 5 on the second end of the valve core 2, thereby pushing the valve core 2 to move and compress the elastic element 3 at the same time, so that the valve core 2 switches from the second working position to the first working position to resume filling the accumulator 200 with a large flow rate.

[0054] The oil drain valve provided by the embodiment of the present invention connects the first oil port 11 and the second oil port 12 on the valve body 1 through the valve core 2, connects the first end of the valve core 2 with the first oil port 11 to form the first feedback oil circuit 4, connects the second end of the valve core 2 with the second oil port 12 to form the second feedback oil circuit 5, and is provided with an elastic element 3 between the first end of the valve core 2 and the valve body 1, so that when the flow direction of the hydraulic oil in the oil drain valve 100 changes, the automatic switching of the working position of the valve core 2 can be realized, and the flow rate of the hydraulic oil flowing through the oil drain valve 100 can be changed by setting the flow rates of different working positions, realizing the automatic control of its output flow rate. When the second oil port 12 of the oil drain valve 100 is connected to the oil outlet of the accumulator 200 for use, when the accumulator 200 switches from oil filling to oil draining, the oil draining flow rate of the oil drain valve 100 can be reduced by automatically switching the working position, preventing the actuator from being damaged due to rigid impact.

[0055] In the embodiment of the present invention, when the valve core 2 works in the first working position and the second working position, the elastic element 3 is in a compressed state, and the elastic force of the elastic element 3 when the valve core 2 works in the first working position is less than the elastic force of the elastic element 3 when the valve core 2 works in the second working position. When the valve core 2 works in the first working position, the elastic restoring force of the elastic element 3 is used to limit the valve core 2 to the first working position. When the valve core 2 switches from the first working position to the second working position, the elastic element 3 is compressed.

[0056] Among them, the elastic element 3 can be a return spring or a return spring piece, etc., which can act on the valve core 2 through the elastic restoring force to limit it to the first working position. One end of the return spring abuts against the first end of the valve core 2, and the other end abuts against the valve body 1.

[0057] Further, a limiting member (not shown in the figure) is provided on the valve body 1. When the valve core 2 works in the first working position, the limiting member prevents the valve core 2 from moving in the direction away from the second working position. When the valve core 2 works in the first working position, the elastic element 3 pushes the valve core 2 to abut against the limiting member, that is, the valve core 2 is limited between the elastic element 3 and the limiting member. Among them, the valve body 1 is provided with a valve core cavity 13, and the limiting member can be a limiting boss or a limiting ring protruding from the inner side wall of the valve core cavity 13; or the limiting member is a snap ring arranged on the inner side wall of the valve core cavity 13.

[0058] Such as Figure 4 and Figure 5 As shown, in the embodiment of the present invention, the valve body 1 of the oil drain valve 100 is provided with an oil passage 14. A first back cavity is formed between the first end of the valve core 2 and the valve body 1, and the elastic element 3 is arranged in the first back cavity. The oil passage 14 communicates the first back cavity and the first oil port 11 to form a first feedback oil passage 4. A cavity 21 is provided at the second end of the valve core 2, and the cavity 21 is communicated with the second oil port 12. A first oil hole 211 is provided on the side wall of the cavity 21, and the cavity 21 is communicated with the first oil port 11 through the first oil hole 211. The opening degree of the first oil hole 211 when the valve core 2 works in the first working position is greater than the opening degree of the first oil hole 211 when the valve core 2 works in the second working position.

[0059] Specifically, the valve body 1 is provided with a valve core cavity 13, and the valve core 2 is slidably installed in the valve core cavity 13 along its axial direction. The first end of the valve body 1 in the sliding direction of the valve core 2 is closed, and the first oil port 11 is opened on one side of the valve body 1 in the sliding direction of the valve core 2. The cavity formed between the first end of the valve body 1 and the first end of the valve core 2 is the first back cavity, and the first back cavity and the first oil port 11 are communicated through the oil passage 14 to form a first feedback oil passage 4.

[0060] The second oil port 12 is opened at the second end of the valve body 1 along the sliding direction of the spool 2, and an axially open cavity is formed between the valve body 1 and the spool 2. This cavity communicates with the second oil port 12 and the cavity 21 to form an oil passage along the axis of the spool 2, and this oil passage is the second feedback oil circuit 5. During the sliding process of the spool 2, the cavity 21 is always connected to the first oil port 11 and the second oil port 12.

[0061] Install the drain valve 100 at the oil outlet of the accumulator 200, and connect the second oil port 12 to the oil outlet of the accumulator 200. When the accumulator 200 discharges oil, the hydraulic oil in the accumulator 200 enters the drain valve 100 along the axis of the spool 2, and then discharges from the first oil port 11 along the radial direction of the spool 2 through the cavity 21. When the accumulator 200 is filled with oil, the external hydraulic oil enters the cavity 21 from the first oil port 11 along the radial direction of the spool 2, and then is filled into the accumulator 200 from the second oil port 12 along the axis of the spool 2.

[0062] It should be noted that the second oil port 12 can also be opened on one side of the valve body 1 along the sliding direction of the spool 2, and the second end of the valve body 1 along the sliding direction of the spool 2 is closed, so that the cavity formed between the second end of the valve body 1 and the second end of the spool 2 is the second back cavity, and the second back cavity communicates with the second oil port 12 to form the second feedback oil circuit 5.

[0063] As Figure 4 shown, when the drain valve 100 is in a stable oil filling state, the hydraulic oil enters the drain valve 100 from the first oil port 11. A part of the hydraulic oil flows from the first oil port 11 into the cavity 21, and the other part of the hydraulic oil flows into the first back cavity through the oil passage 14. At this time, the first end and the second end of the spool 2 are subjected to the same magnitude of hydraulic pressure. At this time, the spool 2 is kept working at the first working position under the action of the elastic element to ensure that the opening of the first oil hole 211 on the spool 2 is the largest, realizing large-flow oil filling.

[0064] As Figure 5 shown, when the drain valve 100 is switched from the above oil filling state to the oil discharging state, due to the change in the flow direction of the liquid oil, the hydraulic oil entering the second feedback oil circuit 5 generates a steady-state hydraulic force, and the steady-state hydraulic force gradually increases. When the resultant force of the steady-state hydraulic force acting on the second end of the spool 2 and the hydraulic pressure is greater than the resultant force of the hydraulic pressure and the elastic force acting on the first end of the spool 2, the spool 2 is pushed to move to the right, and the spool 2 is switched to the second working position. At this time, the opening of the first oil hole 211 on the spool 2 is reduced, so that the first oil port 11 outputs hydraulic oil with a small amount.

[0065] When the oil drain valve 100 is switched from the above-mentioned oil drain state to the oil filling state, due to the change in the flow direction of the hydraulic oil and the throttling effect of the first oil hole 211, the acting force of the hydraulic oil on the first end of the valve core 2 is greater than the acting force of the hydraulic oil on the second end of the valve core 2, thereby pushing the valve core 2 to move leftward and switching the valve core 2 to the first working position. At this time, the opening degree of the first oil hole 211 on the valve core 2 returns to the maximum opening degree, so that the second oil port 12 outputs hydraulic oil at a large flow rate.

[0066] As Figure 1 and Figure 2 shown, the oil drain valve provided by the embodiment of the present invention further includes a damping element 6, and the damping element 6 is arranged on the first feedback oil circuit 4. Among them, the damping element 6 can be a damping hole or a damper or a proportional flow valve arranged on the first feedback oil circuit 4.

[0067] When the valve core 2 of the oil drain valve 100 works in the first working position, the flow direction of the hydraulic oil is switched from the first oil port 11 to the second oil port 12. At this time, due to the existence of the damping element 6, the hydraulic pressure acting on the first end of the valve core 2 cannot be immediately unloaded, so that the valve core 2 remains in the first working position within a certain period of time, enabling the accumulator 200 to have a relatively high outlet flow rate to meet the large flow rate requirements of the working element in the early stage.

[0068] After a certain period of time, as the hydraulic oil is discharged from the first feedback oil circuit 4 to the first oil port 11, the hydraulic pressure acting on the first end of the valve core 2 decreases. When the hydraulic pressure acting on the second end of the valve core 2 is greater than the hydraulic pressure acting on the first end of the valve core 2, the valve core 2 is switched to the second working position to achieve small-flow oil drainage, so as to avoid a large rigid impact at the end of the stroke of the actuator.

[0069] Among them, the matching adjustment of the hydraulic systems of different types of actuators can be realized by replacing damping elements 6 of different specifications. Further, as Figure 3 shown is the third schematic diagram of the working principle of the oil drain valve provided by the present invention.

[0070] In an embodiment of the present invention, the damping element 6 is selected as an adjustable damper. So as to facilitate adjusting the delay time for the oil drain valve 100 to switch from the first working position to the second working position by adjusting the damper. To match the hydraulic systems of different types of actuators.

[0071] In another embodiment of the present invention, the damping element 6 is selected as an electronically controlled proportional flow valve, and the adjustment of the delay time when the oil drain valve 100 switches from the first working position to the second working position can also be achieved.

[0072] In an embodiment of the present invention, the valve body 1 includes a valve seat 15 and a valve sleeve 16. The first oil port 11, the second oil port 12, and the spool cavity 13 are all provided in the valve seat 15, and the valve sleeve 16 is fixed within the spool cavity 13. The spool 2 is slidably disposed within the valve sleeve 16. A second oil hole 162 is provided on the side wall of the valve sleeve 16, and the second oil hole 162 communicates the first oil port 11 and the first oil hole 211.

[0073] Wherein, the first end of the valve sleeve 16 and the first end of the spool 2 correspond to each other and are both in communication with the first oil port 11, and the second end of the valve sleeve 16 and the second end of the spool 2 correspond to each other and are both in communication with the second oil port 12.

[0074] In an embodiment of the present invention, a first back cavity is formed between the first end of the spool 2 and the first end of the valve sleeve 16. A damping hole 161 is provided on the valve sleeve 16, and the damping hole 161 communicates the first back cavity and the oil passage 14. The damping hole 161 serves as Figures 1 - 3 the damping element 6 on the first feedback oil passage 4 as shown, or a damping element 6 is installed at the damping hole 161, so as to realize the switching of the spool 2 from the first working position to the second working position under the action of hydraulic pressure after a certain period of time.

[0075] Optionally, a buffer cavity 17 is formed between the first end of the valve sleeve 16 and the valve seat 15, and the buffer cavity 17 communicates the damping hole 161 and the oil passage 14. The damping hole 161 is provided at the first end of the valve sleeve 16. Optionally, the central axis of the damping hole 161 coincides with the central axis of the spool 2. The first oil port 11, the oil passage 14, the buffer cavity 17, the damping hole 161, and the first back cavity are sequentially communicated to form the first feedback oil passage 4.

[0076] In an embodiment of the present invention, a first annular diversion groove 18 is provided on the inner side surface of the spool cavity 13, and a second annular diversion groove 163 is provided on the inner side surface of the valve sleeve 16. The first oil port 11, the first annular diversion groove 18, the second oil hole 162, the second annular diversion groove 163, and the first oil hole 211 are sequentially communicated. Wherein, the first oil hole 211 includes a plurality of first through holes distributed circumferentially on the side wall of the cavity 21 along the spool 2, and the second oil hole 162 includes a plurality of second through holes distributed circumferentially on the side wall of the valve sleeve 16 along the valve sleeve 16.

[0077] The hydraulic oil entering the cavity 21 from the second oil port 12 can enter the first annular diversion groove 18 through a plurality of first through holes circumferentially arranged on the spool 2, then enter the second annular diversion groove 163 through a plurality of second through holes circumferentially arranged on the valve sleeve 16, and finally flow out from the first oil port 11.

[0078] In the embodiment of the present invention, the first oil hole 211 includes a plurality of first through holes axially distributed on the side wall of the cavity 21 along the valve core 2, and the aperture of the first through hole near the second end of the valve core 2 is smaller than the aperture of the first through hole far from the second end of the valve core 2. In this way, when the valve core 2 is switched from the first working position to the second working position, the control of the oil discharge flow rate can be completed by moving a smaller stroke, which is beneficial to reducing the volume of the oil discharge valve 100. Correspondingly, the second oil hole 162 includes a plurality of second through holes axially distributed on the side wall of the valve sleeve 16 along the valve sleeve 16.

[0079] Further, a plurality of first through holes axially distributed on the side wall of the cavity 21 along the circumferential direction of the valve core 2 form a first oil hole group, and the first oil hole 211 includes a plurality of first oil hole groups axially distributed on the side wall of the cavity 21 along the valve core 2. That is, the plurality of first through holes are arranged in a matrix on the side wall of the cavity 21. Correspondingly, a plurality of second through holes axially distributed on the side wall of the valve sleeve 16 along the circumferential direction of the valve sleeve 16 form a second oil hole group, and the second oil hole 162 includes a plurality of second oil hole groups axially distributed on the side wall of the valve sleeve 16 along the valve sleeve 16. That is, the plurality of second oil holes are arranged in a matrix on the side wall of the valve sleeve 16.

[0080] The present invention also provides an energy storage device, which includes an accumulator 200 and any one of the above oil discharge valves 100. The oil discharge valve 100 is installed at the oil outlet of the accumulator 200, and the oil outlet of the accumulator 200 is communicated with the second oil port 12.

[0081] Among them, the second oil port 12 of the oil discharge valve 100 and the oil outlet of the accumulator 200 can be fixedly connected so that the oil discharge valve 100 and the accumulator 200 are integrated into a whole, which is convenient for the installation of the energy storage device. Alternatively, the second oil port 12 of the oil discharge valve 100 and the oil outlet of the accumulator 200 are detachably connected by threads or flanges, so as to facilitate the installation, disassembly and replacement of the oil discharge valve 100 and the accumulator 200.

[0082] The present invention also provides a hydraulic system. The hydraulic system includes an oil pump, an actuator, an accumulator 200 and any one of the oil discharge valves 100 described in the above embodiments. The first oil port 11 is respectively communicated with the oil outlet of the oil pump and the working oil port of the actuator, and the second oil port 12 is communicated with the oil outlet of the accumulator 200.

[0083] Alternatively, the hydraulic system includes an oil pump, an actuator and the energy storage device described in the above embodiment. The oil outlet of the oil pump is communicated with the first oil port 11, and the first oil port 11 is communicated with the working oil port of the actuator.

[0084] Among them, the oil pump is used to fill hydraulic oil into the accumulator 200 or the energy storage device. When the actuator is unloaded, the accumulator 200 is used to supply hydraulic oil to the actuator. By setting the oil drain valve 100 provided by the present invention, the amount of hydraulic oil supplied by the accumulator 200 to the actuator can be controlled, preventing a large impact on the actuator during the oil draining process of the accumulator 200 to protect the actuator.

[0085] Further, the oil pump can be used as the power source of the actuator, that is, the accumulator and the actuator share the power source. Among them, the hydraulic system further includes a reversing valve, and the oil pump is connected to the actuator through the reversing valve. The reversing valve includes a first reversing port, a second reversing port, an oil inlet, and an oil return port. The oil outlet of the oil pump is respectively connected to the oil inlet of the reversing valve and the first oil port 11 of the oil drain valve 100, the first reversing port and the second reversing port are respectively connected to the first control oil port and the second control oil port of the actuator, and the oil return port of the reversing valve is connected to the fuel tank.

[0086] The reversing valve is provided with a first working position and a second working position. When the spool of the reversing valve works in the first working position, the oil inlet of the reversing valve is connected to the first reversing port, and the oil return port of the reversing valve is connected to the second reversing port. When the spool of the reversing valve works in the second working position, the oil inlet of the reversing valve is connected to the second reversing port, and the oil return port of the reversing valve is connected to the first reversing port.

[0087] When the actuator is a hydraulic cylinder, the first control oil port is connected to the rodless cavity of the hydraulic cylinder, and the second control oil port is connected to the rod cavity of the hydraulic cylinder. During the working process of the hydraulic system, when the spool of the reversing valve works in the first working position, a part of the hydraulic oil pumped out by the oil pump sequentially passes through the oil inlet and the first reversing port of the reversing valve and enters the rodless cavity of the working cylinder to drive the piston of the working cylinder to extend and do work; another part passes through the first oil port 11 and enters the accumulator 200 to fill the accumulator 200 with oil.

[0088] When the spool of the reversing valve works in the second working position, the hydraulic oil pumped out by the oil pump sequentially passes through the oil inlet and the second reversing port of the reversing valve and enters the rod cavity of the working cylinder to drive the piston of the working cylinder to retract. At the same time, the accumulator 200 enters the oil draining state and also supplies hydraulic oil to the rod cavity of the working cylinder to drive the piston of the working cylinder to contract rapidly.

[0089] When a damping element 6 is provided on the first feedback oil circuit 4 of the oil drain valve 100, during a certain period at the beginning when the spool of the reversing valve switches from the first working position to the second working position, that is, during a certain period at the beginning after the spool of the oil drain valve 100 switches from the oil filling state to the oil draining state, the piston of the working oil cylinder can contract at a relatively fast speed. After a certain period, the spool of the oil drain valve 100 switches to the second working position, reducing the output flow of the accumulator 200 to reduce the oil supply to the rod chamber of the working oil cylinder, thereby avoiding a rigid collision between the piston and the cylinder block at the end of the stroke.

[0090] The present invention also provides a working machine, which can be a working machine such as a concrete pump truck, a truck-mounted pump, a trailer pump, a crane, and a fire truck. The working machine includes the hydraulic system described in the above embodiments. When the working machine is a concrete pump truck, the actuating elements include a first swing cylinder and a second swing cylinder. The rodless chamber of the first swing cylinder is communicated with the first reversing port of the reversing valve, the rod chamber of the first swing cylinder is communicated with the rod chamber of the second swing cylinder, and the rodless chamber of the second swing cylinder is communicated with the second reversing port of the reversing valve.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oil drain valve, characterized in that, It includes a valve body, a valve core and an elastic element. The valve body is provided with a first oil port and a second oil port. The valve core is arranged between the first oil port and the second oil port and the valve core communicates with the first oil port and the second oil port. The valve core can move in the valve body so as to switch between a first working position and a second working position; an elastic element is arranged between the first end of the valve core and the valve body. The first end of the valve core communicates with the first oil port, and the second end of the valve core communicates with the second oil port; When the hydraulic oil in the oil drain valve flows from the first oil port to the second oil port, the valve core can switch from the second working position to the first working position under the action of the elastic element; When the hydraulic oil in the oil drain valve flows from the second oil port to the first oil port, the valve core can compress the elastic element and switch from the first working position to the second working position; the flow rate of the oil drain valve when the valve core works in the second working position is less than the flow rate when the valve core works in the first working position; An oil passage is arranged in the valve body. A first back cavity is formed between the first end of the valve core and the valve body. The elastic element is arranged in the first back cavity. The oil passage communicates with the first back cavity and the first oil port to form a first feedback oil passage; A cavity is arranged at the second end of the valve core. The cavity is communicated with the second oil port. A first oil hole is arranged on the side wall of the cavity. The cavity is communicated with the first oil port through the first oil hole; when the valve core works in the first working position, the opening degree of the first oil hole is greater than the opening degree of the first oil hole when the valve core works in the second working position.

2. The oil drain valve according to claim 1, wherein When the valve core works in the first working position and the second working position, the elastic element is in a compressed state, and the elastic force of the elastic element when the valve core works in the first working position is less than the elastic force when the valve core works in the second working position.

3. The oil drain valve according to claim 1, characterized in that, A limiting member is arranged on the valve body. When the valve core works in the first working position, the limiting member prevents the valve core from moving in the direction away from the second working position.

4. The drain valve according to claim 1, characterized in that, It further includes a damping element. The damping element is arranged on the first feedback oil passage.

5. The oil drain valve according to claim 4, characterized in that, The damping element is any one of a damping hole, a damper and an electronically controlled proportional flow valve.

6. The oil drain valve according to claim 5, characterized in that, The damper is an adjustable damper.

7. The oil drain valve according to claim 3, characterized in that, The valve body includes a valve seat and a valve sleeve. The first oil port and the second oil port are both arranged on the valve seat. The valve seat is provided with a valve core cavity. The valve sleeve is fixed in the valve core cavity. The valve core is slidably arranged in the valve sleeve; a second oil hole is arranged on the side wall of the valve sleeve. The second oil hole communicates with the first oil port and the first oil hole.

8. The oil drain valve according to claim 7, characterized in that, The first back cavity is formed between the first end of the valve core and the first end of the valve sleeve. A damping hole is arranged on the valve sleeve. The damping hole communicates with the first back cavity and the oil passage.

9. The oil drain valve according to claim 7, characterized in that, A first annular diversion groove is arranged on the inner side surface of the valve core cavity. A second annular diversion groove is arranged on the inner side surface of the valve sleeve. The first oil port, the first annular diversion groove, the second oil hole, the second annular diversion groove and the first oil hole are communicated in sequence; The first oil hole includes a plurality of first through holes circumferentially distributed on the side wall of the cavity along the spool, and the second oil hole includes a plurality of second through holes circumferentially distributed on the side wall of the valve sleeve along the valve sleeve.

10. The drain valve according to claim 3, wherein The first oil hole includes a plurality of first through holes axially distributed on the side wall of the cavity along the spool, and the aperture of the first through hole near the second end of the spool is smaller than the aperture of the first through hole far from the second end of the spool.

11. The oil drain valve according to any one of claims 1 to 3, characterized in that, The elastic element is a return spring.

12. An energy storage device, characterized in that, It includes an accumulator and an oil drain valve according to any one of claims 1-11, the oil drain valve is installed at the oil outlet of the accumulator, and the oil outlet of the accumulator is communicated with the second oil port.

13. A hydraulic system, characterized in that, It includes an oil pump, an actuator, an accumulator and an oil drain valve according to any one of claims 1-11, the first oil port is respectively communicated with the oil outlet of the oil pump and the working oil port of the actuator, and the second oil port is communicated with the oil outlet of the accumulator; Alternatively, the hydraulic system includes an oil pump, an actuator and an energy storage device according to claim 12.

14. An earthmoving machine, characterized in that, It includes a hydraulic system according to claim 13.

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