Three-position four-way reversing valve

Abstract

The invention provides a three-position four-way reversing valve which comprises a valve body and an end cover, a valve sleeve, a first valve element and a second valve element are arranged in the valve body, the first valve element is movably arranged in the valve sleeve, and the second valve element is movably arranged in the first valve element. The second valve element moves to drive the first valve element to move so that liquid circulation can be controlled. According to the embodiment of the invention, pressure control in the prior art is replaced by position control of a plurality of valve elements in reversing and flow regulation, so that the valve has the outstanding advantages of more accurate control, lower control difficulty and the like, and has the characteristics of compact and simple structure and the like.

Description

Technical Field

[0001] The present disclosure relates to the technical field of directional control valves, and more particularly, to a three-position four-way directional control valve. Background Art

[0002] The electro-hydraulic control directional control valve is the control core component of the electro-hydraulic control system. It is a hydraulic directional control valve formed by combining an electromagnetic pilot valve and a main valve. The high-pressure liquid in the liquid path of the electromagnetic pilot valve is used to push the main valve spool to control the movement of the actuator. As a key component of the electro-hydraulic control of the hydraulic cylinder, the electro-hydraulic control directional control valve plays an important role in realizing the comprehensive mechanization, automation, and intelligent control of the hydraulic system. At the same time, with the popularization and application of intelligent control in various industries, the requirement for the control accuracy of the hydraulic system is getting higher and higher, and there is a need for flow regulation of the electro-hydraulic control directional control valve, so as to control the speed and direction of the actuator and achieve more precise control.

[0003] The flow control of the existing directional control valve depends on the opening degree of the main valve spool, and the opening degree of the main valve spool is determined by the balance position between the pilot liquid pressure and the spring force. The core of realizing high-precision flow control lies in controlling the pilot liquid pressure. The pilot liquid pressure in the prior art is regulated by controlling the opening degree of an electromagnetic pressure reducing valve, and there is also a solution that uses a high-speed switching valve for regulation. These solutions all have the problem of energy waste caused by continuous liquid drainage and pressure reduction, and put very high requirements on the design and processing of the electromagnet, pilot valve spool, and main valve spool. Currently, it is difficult to design and manufacture a high-precision electro-hydraulic proportional directional control valve and the cost is high. Summary of the Invention

[0004] In view of this, the present disclosure aims to provide a three-position four-way directional control valve to solve the technical problems such as energy waste caused by continuous liquid drainage and pressure reduction in the prior art and very high requirements for the design and processing of the electromagnet, pilot valve spool, and main valve spool.

[0005] The present disclosure provides a three-position four-way directional control valve, including a valve body and an end cover. A valve sleeve, a first valve spool, and a second valve spool are arranged in the valve body. The first valve spool is movably arranged in the valve sleeve, and the second valve spool is movably arranged in the first valve spool. By moving the second valve spool and driving the movement of the first valve spool, the flow of liquid is controlled.

[0006] In some embodiments, the valve sleeve adopts a cylindrical structure. An inlet liquid ring groove, a first working ring groove, a second working ring groove, and two return liquid ring grooves are arranged on the outer wall of the valve sleeve. The first working ring groove and the second working ring groove are symmetrically arranged with respect to the center line of the inlet liquid ring groove, and the two return liquid ring grooves are symmetrically arranged with respect to the center line of the inlet liquid ring groove.

[0007] In some embodiments, a liquid inlet, a liquid return port, a first working port, and a second working port are provided on the valve body; the liquid inlet communicates the system liquid inlet with the liquid inlet annular groove, the liquid return port communicates the system liquid return with the two liquid return annular grooves, the first working port communicates the actuator with the first working annular groove, and the second working port communicates the actuator with the second working annular groove.

[0008] In some embodiments, radial liquid passing holes are provided in the liquid inlet annular groove, the first working annular groove, the second working annular groove, and the two liquid return annular grooves, and the liquid in each annular groove enters the inside of the valve sleeve through the radial liquid passing holes.

[0009] In some embodiments, sealing rings are provided between the liquid inlet annular groove, the first working annular groove, the second working annular groove, and the two liquid return annular grooves.

[0010] In some embodiments, a pilot liquid inlet channel is provided in the middle of the first valve core, pilot liquid return channels are symmetrically provided on both sides of the pilot liquid inlet channel, a first liquid passing annular groove and a second liquid passing annular groove are respectively provided between the pilot liquid inlet channel and each pilot liquid return channel, and a first pilot liquid return annular groove and a second pilot liquid return annular groove are respectively provided outside the two pilot liquid return channels.

[0011] In some embodiments, a third liquid passing annular groove and a fourth liquid passing annular groove are symmetrically provided on the outer wall of the second valve core, and the third liquid passing annular groove and the fourth liquid passing annular groove are respectively communicated with the end faces on both sides of the second valve core through internal liquid passing channels.

[0012] In some embodiments, on the side of the valve body away from the end cover, the inner wall of one side of the valve body, the end face of the first valve core, and the end face of the second valve core enclose to form a first control cavity; on the other side of the valve body close to the end cover, the end face of the first valve core, the end face of the second valve core, and the end face of the end cover enclose to form a second control cavity.

[0013] In some embodiments, springs are respectively provided at both ends of the first valve core, one ends of the two springs are connected to the end face of the first valve core, and the other ends of the two springs respectively abut against the bottom surface of the valve body and the inner surface of the end cover.

[0014] In some embodiments, the end of the second valve core facing the end cover is connected to the first end of a connecting rod, and a driving assembly for driving the second valve core to reciprocate is connected to the second end of the connecting rod.

[0015] In the embodiments of the present disclosure, position control of multiple spool valves is used to replace pressure control in the prior art solutions during commutation and flow regulation, which has prominent advantages such as more precise control and lower control difficulty, and also has characteristics such as a compact and simple structure.

[0016] To make the above objects, features, and advantages of the present disclosure more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same reference numerals with alphabetic suffixes or different alphabetic suffixes may represent different instances of similar components. The drawings generally illustrate various embodiments by way of example rather than limitation, and are used together with the description and the claims to explain the disclosed embodiments. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be an exhaustive or exclusive embodiment of the apparatus or method. The drawings described herein are used to provide a further understanding of the present disclosure, form a part of this application, and the illustrative embodiments and descriptions thereof are used to explain the present disclosure without unduly limiting the present disclosure. In the drawings:

[0018] Figure 1 is a schematic diagram of the structure of a three-position four-way directional control valve provided by an embodiment of the present disclosure and in an initial state;

[0019] Figure 2 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a first state;

[0020] Figure 3 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a second state;

[0021] Figure 4 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a third state;

[0022] Figure 5 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a fourth state;

[0023] Figure 6 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a fifth state;

[0024] Figure 7 is a schematic diagram of the three-position four-way directional control valve provided by an embodiment of the present disclosure in a sixth state;

[0025] Figure 8It is a schematic diagram of the three-position four-way directional control valve provided by the embodiments of the present disclosure in the seventh state;

[0026] Figure 9 It is a schematic structural diagram of another three-position four-way directional control valve provided by the embodiments of the present disclosure.

[0027] Among them, the above-mentioned drawings include the following reference numerals:

[0028] 1 - valve body; 2 - valve sleeve; 3 - first spool; 4 - second spool; 5 - end cover; 6 - spring; 7 - connecting rod; 8 - driving assembly. Detailed Embodiments

[0029] Next, specific embodiments of the present disclosure will be described in detail with reference to the drawings, but it is not a limitation of the present disclosure.

[0030] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be regarded as a limitation, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present disclosure.

[0031] The drawings included in the specification and constituting a part of the specification show the embodiments of the present disclosure, and together with the general description of the present disclosure given above and the detailed description of the embodiments given below, are used to explain the principles of the present disclosure.

[0032] These and other features of the present disclosure will become apparent from the following description of the preferred forms of the embodiments given by way of non-limiting examples with reference to the drawings.

[0033] It should also be understood that although the present disclosure has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present disclosure, which have the features as described in the claims and thus are all within the protection scope defined thereby.

[0034] When combined with the drawings, the above and other aspects, features, and advantages of the present disclosure will become more apparent in view of the following detailed description.

[0035] Hereinafter, specific embodiments of the present disclosure will be described with reference to the drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details from obscuring the present disclosure. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but are merely used as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in substantially any suitable detailed structure in a variety of ways.

[0036] It should be noted that the terms "first", "second", etc. in the specification, claims and the above-mentioned drawings of the present disclosure are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0037] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", all of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0038] An embodiment of the present disclosure provides a three-position four-way directional control valve, as Figure 1 shown, the three-position four-way directional control valve includes a valve body 1 and a valve cover 5. A valve sleeve 2, a first spool 3 and a second spool 4 are arranged inside the valve body 1. The second spool 4 here is arranged inside the first spool 3. The valve sleeve 2 and the valve body 1 here can be tightly connected by a threaded manner, and in other embodiments, they can also be connected in other forms such as flanges, and the specific connection form is not limited.

[0039] The end cover 5 and the valve sleeve 2 here can also be connected by a tightening method, which is used to limit the first spool 3 and the second spool 4 inside the valve sleeve 2, and a sealing structure is provided to prevent the liquid inside the valve sleeve 2 from leaking out.

[0040] Specifically, the valve body 1 here adopts a cylindrical structure. Along its length direction on the outer wall of the valve body 1, a liquid inlet, a liquid return port, a first working port, and a second working port are provided. Among them, the liquid inlet is located in the middle, the first working port and the second working port are respectively located on both sides of the liquid inlet, and the liquid return ports are respectively arranged outside the first working port and the second working port. The liquid inlet here is connected to the external system liquid inlet to serve as the input end of high-pressure liquid, and the liquid return port is connected to the external system liquid return, which has no pressure or the pressure is much lower than the liquid inlet pressure. The first working port and the second working port here serve as control ports to connect the actuators. For example, a hydraulic cylinder and a hydraulic motor can be respectively connected through the first working port and the second working port, and the movement direction and movement speed of different actuators can be adjusted by controlling the liquid flow direction and flow rate inside the three-position four-way directional control valve. An inlet chamber is formed inside the liquid inlet, a return chamber is formed inside the liquid return port, and working chambers are respectively formed inside the first working port and the second working port.

[0041] Furthermore, the valve sleeve 2 adopts a cylindrical structure. Along the length direction of the valve sleeve 2 on its outer wall, a liquid inlet ring groove P, a first working ring groove A, a second working ring groove B, and two liquid return ring grooves T are provided. Through the internal flow path of the valve body 1, the liquid inlet ring groove P is connected to the liquid inlet on the valve body 1, the two liquid return ring grooves T are simultaneously connected to the liquid return port, the first working ring groove A is connected to the first working port, and the second working ring groove B is connected to the second working port. In this way, the liquid inlet ring groove P is located in the middle of the valve sleeve 2, the first working ring groove A and the second working ring groove B are located on both sides of the liquid inlet ring groove P, and the liquid return ring grooves T are respectively arranged outside the first working ring groove A and the second working ring groove B. Among them, the first working ring groove A and the second working ring groove B have the same size, and the two liquid return ring grooves T have the same size.

[0042] Specifically, the liquid inlet ring groove P, the first working ring groove A, the second working ring groove B, and the two liquid return ring grooves T sequentially form five chambers. Among them, the first working ring groove A and the second working ring groove B are symmetrically arranged with respect to the center line of the liquid inlet ring groove P. Similarly, the two liquid return ring grooves T are symmetrically arranged with respect to the center line of the liquid inlet ring groove P.

[0043] Furthermore, the inside of the valve sleeve 2 here is set as a through smooth cylindrical surface. Radial liquid passing holes are provided in the above-mentioned respective ring grooves, and through the radial liquid passing holes, the liquid in each ring groove can enter the inside of the valve sleeve 2.

[0044] Furthermore, sealing rings are provided between the liquid inlet ring groove P, the first working ring groove A, the second working ring groove B, and the two liquid return ring grooves T. Through the sealing rings, the five chambers can be separated to prevent liquid from flowing between different chambers.

[0045] In this embodiment, the first valve core 3 is arranged inside the valve sleeve 2. It can adopt a hollow cylindrical structure. By setting reasonable shape parameters, the outer wall of the first valve core 3 is closely fitted with the inner wall of the valve sleeve 2. The first valve core 3 can reciprocate along the length direction of the valve sleeve 2 inside the valve sleeve 2. By different moving positions, the flow of liquid can be prevented, thus achieving the effect of controlling the liquid flow.

[0046] Furthermore, a pilot liquid inlet channel Px is arranged in the middle of the first valve core 3. Pilot liquid return channels Tx are symmetrically arranged on both sides of the pilot liquid inlet channel Px. A first liquid passing ring groove Ad and a second liquid passing ring groove Bd are respectively arranged along the length direction of the first valve core 3 between the pilot liquid inlet channel Px and the two pilot liquid return channels Tx. First pilot liquid return ring grooves Ta and second pilot liquid return ring grooves Tb are respectively arranged along the length direction of the first valve core 3 outside the two pilot liquid return channels Tx. Among them, the first liquid passing ring groove Ad and the second liquid passing ring groove Bd have the same size, and the first pilot liquid return ring groove Ta and the second pilot liquid return ring groove Tb have the same size.

[0047] The inside of the first valve core 3 here is set as a through smooth cylindrical surface. The pilot liquid inlet channel Px is used to connect the inner hole of the second valve core 4 and the liquid inlet ring groove P. The two pilot liquid return channels Tx are respectively used to connect the first pilot liquid return ring groove Ta and the second pilot liquid return ring groove Tb on both sides and the liquid return ring groove T.

[0048] Furthermore, the second valve core 4 is arranged inside the first valve core 3. It can adopt a cylindrical structure. By setting reasonable shape parameters, the outer wall of the second valve core 4 is closely fitted with the inner wall of the first valve core 3. The second valve core 4 can reciprocate along the length direction of the first valve core 3 inside the first valve core 3. By different moving positions, the flow of liquid can be prevented, thus achieving the effect of controlling the liquid flow.

[0049] In addition, in order to enhance the effect of the first valve core 3 and the second valve core 4 in blocking the medium flow between chambers, a sealing member can be arranged at the closely fitted position.

[0050] Further, a third liquid passing ring groove Ax and a fourth liquid passing ring groove Bx are provided on the outer wall of the second valve core 4 along its length direction. Among them, the third liquid passing ring groove Ax and the fourth liquid passing ring groove Bx are respectively communicated with the end faces on both sides through internal liquid passing channels. Among them, the third liquid passing ring groove Ax and the fourth liquid passing ring groove Bx have the same size.

[0051] Further, on the side of the valve body 1 away from the end cover 5, the inner wall of one side of the valve body 1, the end face of the first valve core 3, and the end face of the second valve core 4 enclose to form a first control cavity KA. On the other side of the valve body 1 close to the end cover 5, the end face of the first valve core 3, the end face of the second valve core 4, and the end face of the end cover 5 enclose to form a second control cavity KB.

[0052] The first valve core 3 is in a zero-position control state during initial installation. In this zero-position control state, the center of the first valve core 3 is oppositely arranged with the center of the liquid inlet ring groove P, and each

[0053] ring groove is in a symmetric structure.

[0054] In some embodiments, as Figure 9 shown, in order to ensure that the first valve core 3 maintains the zero position state during initial installation, springs 6 are respectively arranged at both ends of the first valve core 3. The two springs 6 have the same shape and the same compression state. One ends of the two springs 6 are both connected to the end face of the first valve core 3, and the other ends of the two springs 6 respectively abut against the bottom surface of the valve body 1 and the inner surface of the end cover 5, or can also be connected to components that remain relatively stationary with the valve sleeve 2.

[0055] In other embodiments, in order to ensure the control effect and control accuracy, a displacement sensor (not shown) is provided on the first valve core 3 and / or the second valve core 4, and the position information of the first valve core 3 and / or the second valve core 4 is fed back to an external control device to form a displacement closed-loop control. In other embodiments, a flow sensor (not shown) can also be provided at the position of the first working port and / or the second working port, and the output flow information is fed back to the external control device to form a flow closed-loop control.

[0056] The three-position four-way reversing valve of this embodiment can realize the function of controlling the reverse flow of liquid. During the control process of the three-position four-way reversing valve, by controlling the reciprocating movement of the second valve core 4, the high-pressure liquid in the liquid inlet ring groove P enters the first control cavity KA or the second control cavity KB, and then drives the first valve core 3 to move accordingly, so that the first valve core 3 blocks the liquid return cavity and connects the working cavity and the liquid inlet cavity, achieving the purpose of controlling the flow direction of the medium.

[0057] Further, continue as Figure 9 shown. To control the second spool 4, the end of the second spool 4 facing the end cap 5 is connected to the first end of the connecting rod 7, and a driving assembly 8 is connected to the second end of the connecting rod 7. Here, the cooperation of the driving assembly 8 and the connecting rod 7 is used to control the movement of the second spool 4. In addition, since the second spool 4 is smaller in size and subject to less load, a driving assembly with lower power can be used for control, making it easier to achieve control in situations where the power consumption at the control end is limited.

[0058] Further, the connecting rod 7 here can pass through the end cap 5, and corresponding seals are provided between the connecting rod 7 and the end cap 5. In another embodiment, the driving assembly is integrally provided inside the valve body 1 and inside the end cap 5.

[0059] The driving assembly 8 here can be a manual lifting device, or an electro-controlled translation device such as an electromagnet or a linear motor, as long as it can drive the second spool 4 to reciprocate.

[0060] The working principle of the three-position four-way directional control valve according to the embodiments of the present disclosure is as follows:

[0061] As Figure 1 shown, in the initial state, the first spool 3 is in the zero-position control state. At this time, the first liquid-passing ring groove Ad connects the first working ring groove A and the return liquid ring groove T on one side, and the second liquid-passing ring groove Bd connects the second working ring groove B and the return liquid ring groove T on the other side. This makes the two working ring grooves on both sides communicate with the return liquid ring groove T at the same time, and there is a predetermined distance between the first liquid-passing ring groove Ad and the second liquid-passing ring groove Bd and the liquid inlet ring groove P. At this time, the first spool 3, the second spool 4 and each channel maintain static balance, without any action or medium flow.

[0062] Here, by setting the spring 6, it is convenient to make the first spool 3 in the zero-position control state. Among them, when the first spool 3 is in the zero-position control state, the spring forces of the two springs 6 on both sides are the same; when the first spool 3 moves a certain distance in any direction, the spring force on one side decreases while the spring force on the other side increases, which will cause the unbalance of the forces on both sides of the first spool 3. At this time, it is necessary to adjust the structural parameter settings of the second spool 4 to change the position of the first spool 3. Specifically, the third liquid-passing ring groove Ax of the second spool 4 is simultaneously communicated with the pilot liquid inlet channel Px and the pilot liquid return channel Tx, and a liquid pressure FKA that just balances the spring force is formed in one side of the control chamber, that is, fKA + FKA = fKB (here it is assumed that after the first spool 3 moves to the right, fKA < fKB). In this way, the first spool 3 will be in a dynamic balance state. As the moving distance of the first spool 3 is different, the magnitudes of fKA and fKB are also different. However, since the second spool 4 is controlled not to act, the first spool 3 realizes floating automatic balance, that is, it will automatically find and adjust the balance point of the opening degree of the communication between the third liquid-passing ring groove Ax and the pilot liquid inlet channel Px and the pilot liquid return channel Tx, so as to achieve the above dynamic balance state.

[0063] As Figure 2 shown, when the second spool 4 moves in the direction towards the valve cover 5 ( Figure 2 the right side in

[0064] As Figure 3 shown, when the second spool 4 continues to move in the direction towards the valve cover 5 ( Figure 3moves to the right side in (the figure) and moves to the working position. When the third liquid passing ring groove Ax communicates with the pilot liquid inlet channel Px, the core part on the left side of the third liquid passing ring groove Ax completely blocks the pilot liquid return channel Tx. The high-pressure liquid enters the first control cavity KA through the third liquid passing ring groove Ax and the internal channel of the second valve core 4, causing the pressure in the cavity to rise. At this time, the left side of the first valve core 3 is affected by the liquid pressure, while the right side of the first valve core 3 continues to communicate with the liquid return ring groove T without pressure, causing the first valve core 3 to move to the right under the action of the liquid pressure.

[0065] As Figure 4 shown, the first valve core 3 continues to move in the direction towards the valve cover 5 ( Figure 4 the right side in the figure) under the action of the liquid pressure. At this time, the second valve core 4 does not move under the action of the external control device. In this way, after the first valve core 3 moves to the right for a certain distance, the communication between the third liquid passing ring groove Ax and the pilot liquid inlet channel Px will be disconnected and at the same time it will communicate with the pilot liquid return channel Tx on one side. The high-pressure liquid in the first control cavity KA will be quickly discharged through the pilot liquid return channel Tx, so that the liquid pressures on both sides of the first valve core 3 are rebalanced, and at this time the relative positions of the first valve core 3 and the second valve core 4 are in the above dynamic balance state.

[0066] At this time, although the first valve core 3 moves a certain distance in the direction towards the valve cover 5 ( Figure 4 the right side in the figure), only the core part outside the first liquid passing ring groove Ad blocks a part of the pilot liquid return channel Tx, but the pilot liquid inlet channel Px is not yet communicated.

[0067] As Figure 5 shown, if it is necessary to change the connection state of each chamber through the first valve core 3, it is necessary to continue to move the second valve core 4 in the direction towards the valve cover 5 ( Figure 5 the right side in the figure). Using the above-mentioned valve core following action, the first valve core 3 continues to move to the right. In this way, by controlling the second valve core 4 to continue to move in the first direction, the first valve core 3 is in a follow-up state to regulate the output or input of the fluid medium to the corresponding working port. As Figure 5 shown, when the second valve core 4 continues to move in the direction towards the valve cover 5 ( Figure 5Move (to the right side in []) to the connected position. Here, based on following motion, when the first valve core 3 moves to a position where the first liquid passage ring groove Ad communicates with the liquid inlet ring groove P, the pilot liquid return passage Tx is blocked simultaneously to prevent liquid from entering the pilot liquid return ring groove Ta, and the second liquid passage ring groove Bd communicates completely with the corresponding liquid return ring groove. In this way, the first liquid passage ring groove Ad of the first valve core 3 always communicates with the first working port A, and the second liquid passage ring groove Bd of the first valve core 3 always communicates with the second working port B.

[0068] When the first valve core 3 is in the following state, the moving distance of the first valve core 3 is the same as that of the second valve core 4. In this way, the moving direction and distance of the first valve core 3 completely follow those of the second valve core 4.

[0069] Specifically, due to the following state between the first valve core 3 and the second valve core 4, even if the first valve core 3 changes the communication state of each chamber to allow liquid to flow between the chambers, but if the position of the second valve core 4 does not change, the dynamic position of the first valve core 3 will not change. Also, since the medium flow rate through the hydraulic valve is positively correlated with the opening degree of the first valve core 3 (i.e., the relative position between the first valve core 4 and the liquid inlet ring groove P of the valve sleeve 2), the position of the first valve core 3 can be controlled through the position of the second valve core 4, and finally, the output or input of a certain flow rate of fluid medium to the corresponding working port can be regulated.

[0070] Figure 6 As shown, when the first valve core 3 moves to a position where the first liquid passage ring groove Ad just communicates with the liquid inlet ring groove P, when the first valve core 3 has a locking structure size, the first valve core 3 just completely shields the pilot liquid return passage Tx, so that the working port does not communicate with either the pilot liquid inlet passage Px or the pilot liquid return passage Tx; in other embodiments, when the first valve core 3 has a non-locking structure size, the size of the first valve core 3 is set such that only one of the pilot liquid inlet passage Px and the pilot liquid return passage Tx can be shielded. For example, the pilot liquid return passage Tx can be completely shielded first, and then the first liquid passage ring groove Ad can be communicated with the liquid inlet ring groove P by moving the first valve core 3. At this time, a locking state where the working port neither communicates with the liquid inlet port nor the liquid return port will be achieved. As Figure 7 and Figure 8 shown, the first valve core 3 and the second valve core 4 continue to move in the direction towards the valve cover 5 ( Figure 7Move it to the right (on the right side in the figure) until the right end face of the first spool 3 abuts against the end cover to reach a preset limit position. At this time, even if there is high-pressure liquid in the first control chamber KA, the generated liquid pressure will be transmitted to the end cover and prevent it from moving. At the same time, a limiting device (not shown in the figure) for the second spool 4 is provided to ensure that the movement of the second spool 4 does not exceed the preset limit position. During the entire control process of the second spool 4, the pilot liquid inlet channel Px is always in communication with the liquid inlet, and the first pilot liquid return annular groove Ta and the second pilot liquid return annular groove Tb are always in communication with the liquid return port.

[0071] Due to the symmetrical arrangement of the first spool 3 and the second spool 4, at any of the above positions, if it is necessary to reduce the opening degree of the first spool 3 or switch to the second working port B for liquid inlet, it is only necessary to move the second spool 4 to the other side, that is, the second direction (i.e., move to the left in the figure). In other words, by moving the second spool 4 left and right, the connection direction and flow rate of the three-way four-way directional control valve can be arbitrarily adjusted.

[0072] In the embodiments of the present disclosure, during commutation and flow regulation, position control of multiple spools is used to replace pressure control in the prior art solutions, which has prominent advantages such as more precise control and lower control difficulty. At the same time, it has the characteristics of compact and simple structure.

[0073] The above has described multiple embodiments of the present disclosure in detail, but the present disclosure is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications to the embodiments based on the concept of the present disclosure, and these variations and modifications should fall within the scope required to be protected by the present disclosure.

[0074] In the above embodiments of the present disclosure, the descriptions of the various embodiments have their respective emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0075] For ease of description, spatial relative terms such as "above...", "above...", "on the upper surface of...", "above" can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation except for the orientation of the device described in the figures. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned "below other devices or structures" or "beneath other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned or rotated in other different ways by 90 degrees or in other orientations, and corresponding explanations are made for the spatial relative descriptions used here.

[0076] In addition to the above, it should be noted that the "one embodiment", "another embodiment", "embodiment" and the like mentioned in this specification refer to the specific features, structures or characteristics described in connection with that embodiment being included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in connection with any one embodiment, it is intended that the implementation of such feature, structure or characteristic in combination with other embodiments also fall within the scope of this disclosure.

[0077] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0078] The above are only the preferred embodiments of this disclosure and are not intended to limit this disclosure. For those skilled in the art, various modifications and changes can be made to this disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this disclosure shall be included within the protection scope of this disclosure.

Claims

1. A three-position four-way directional control valve, characterized in that, It includes a valve body and an end cover. A valve sleeve, a first valve core and a second valve core are arranged inside the valve body. The first valve core is movably arranged inside the valve sleeve, and the second valve core is movably arranged inside the first valve core. By moving the second valve core and driving the movement of the first valve core, the control of liquid flow is realized.

2. The three-position four-way reversing valve according to claim 1, characterized in that, The valve sleeve adopts a cylindrical structure. An inlet liquid ring groove, a first working ring groove, a second working ring groove and two return liquid ring grooves are arranged on the outer wall of the valve sleeve. The first working ring groove and the second working ring groove are symmetrically arranged with respect to the center line of the inlet liquid ring groove, and the two return liquid ring grooves are symmetrically arranged with respect to the center line of the inlet liquid ring groove.

3. The four-way three-position reversing valve according to claim 2, characterized in that, An inlet liquid port, a return liquid port, a first working port and a second working port are arranged on the valve body; the inlet liquid port connects the system inlet liquid with the inlet liquid ring groove, the return liquid port connects the system return liquid with the two return liquid ring grooves, the first working port connects the actuator with the first working ring groove, and the second working port connects the actuator with the second working ring groove.

4. The three-position four-way reversing valve according to claim 2, characterized in that, Radial liquid passing holes are arranged in the inlet liquid ring groove, the first working ring groove, the second working ring groove and the two return liquid ring grooves. Through the radial liquid passing holes, the liquid in each ring groove enters the inside of the valve sleeve.

5. The four-way three-position directional control valve according to claim 2, characterized in that, Sealing rings are arranged between the inlet liquid ring groove, the first working ring groove, the second working ring groove and the two return liquid ring grooves.

6. The four-way three-position directional control valve according to claim 2, wherein A pilot inlet liquid channel is arranged in the middle of the first valve core. Pilot return liquid channels are symmetrically arranged on both sides of the pilot inlet liquid channel. A first liquid passing ring groove and a second liquid passing ring groove are respectively arranged between the pilot inlet liquid channel and each pilot return liquid channel. First pilot return liquid ring grooves and second pilot return liquid ring grooves are respectively arranged on the outer sides of the two pilot return liquid channels.

7. The four-way three-position directional control valve according to claim 1, characterized in that, Third liquid passing ring grooves and fourth liquid passing ring grooves are symmetrically arranged on the outer wall of the second valve core. The third liquid passing ring groove and the fourth liquid passing ring groove are respectively communicated with the end faces on both sides of the second valve core through internal liquid passing channels.

8. The four-way three-position directional control valve according to claim 1, characterized in that, On the side of the valve body away from the end cover, the inner wall of one side of the valve body, the end face of the first valve core and the end face of the second valve core enclose to form a first control cavity; on the other side of the valve body close to the end cover, the end face of the first valve core, the end face of the second valve core and the end face of the end cover enclose to form a second control cavity.

9. The four-way three-position directional control valve according to claim 1, wherein Springs are respectively arranged at both ends of the first valve core. One ends of the two springs are both connected to the end face of the first valve core, and the other ends of the two springs respectively abut against the bottom surface of the valve body and the inner surface of the end cover.

10. The three-position four-way directional control valve according to claim 1, characterized in that, The end of the second valve core facing the end cover is connected to the first end of a connecting rod, and a driving assembly for driving the second valve core to reciprocate is connected to the second end of the connecting rod.

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