Electromagnetic reversing valve
By designing a three-position six-way structure solenoid reversing valve, the problem of lack of median unloading function in the hydraulic system is solved, the median unloading function is realized, the cost is reduced, and the chip-type multi-channel control valve is suitable for complex mechanical equipment.
Patent Information
- Application Number
- CN202422311267.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-09-20
AI Technical Summary
In existing hydraulic systems, the three-position four-way valve lacks the median unloading function in the middle, resulting in pressure instability and vibration problems, especially when using a quantitative pump.
An electromagnetic reversing valve is designed, with a three-position and six-way structure. By forming an oil inlet, a working oil port, a return oil port, an auxiliary oil port and a pressure oil tank in the valve body, the first auxiliary oil port and the second auxiliary oil port are connected in the middle, providing an unloading channel, and axial sliding of the valve core is used to drive the valve core to achieve valve position switching.
It realizes the median unloading function, is suitable for quantitative pump systems, reduces costs, and is suitable for complex mechanical equipment such as chip multi-channel control valves in engineering machinery and agricultural machinery.
Smart Images
Figure CN223090054U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to an electromagnetic directional control valve. Background Art
[0002] In a hydraulic system, a control valve is required to implement the functions of an actuator. For a hydraulic system with relatively complex operations, such as those in construction machinery, agricultural machinery, etc., the control valves for each actuator can be integrated together to form a wafer - type multi - way control valve. In such a wafer - type multi - way control valve, the directional control valve usually adopts an electro - hydraulic pilot - operated method to achieve valve position switching, resulting in a relatively high cost. On the other hand, the shift directional control valve is a three - position four - way valve, and the oil inlet and the oil return port are disconnected in the neutral position, so it does not have a neutral unloading function. When a fixed - displacement pump is used as the hydraulic source in the hydraulic system, it will cause problems such as unstable pressure and vibration in the hydraulic system. Utility Model Content
[0003] An object of the present application is to provide an improved electromagnetic directional control valve that can achieve a neutral unloading function.
[0004] To this end, in one aspect of the present application, an electromagnetic directional control valve is provided, which includes:
[0005] A valve body;
[0006] A spool, which is installed in the valve body in an axially slidable manner; and
[0007] An electromagnet installed at at least one control end of the valve body, configured to drive the spool to axially slide in the valve body so that the electromagnetic directional control valve realizes valve position switching;
[0008] Wherein, an oil inlet, a first working oil port, a second working oil port, an oil return port, a first auxiliary oil port, and a second auxiliary oil port are formed on the valve body, and a pressure oil groove is formed on the spool. Among them, in the neutral position of the electromagnetic directional control valve, the first auxiliary oil port and the second auxiliary oil port are communicated through the pressure oil groove, so that the first auxiliary oil port and the second auxiliary oil port are communicated to form an unloading channel.
[0009] According to an embodiment, in the valve body, the first auxiliary oil port leads to a first auxiliary oil cavity, the second auxiliary oil port leads to a pair of second auxiliary oil cavities formed on both axial sides of the first auxiliary oil cavity, and the pressure oil groove includes a pair of pressure oil grooves axially spaced from each other. Among them, in the neutral position of the electromagnetic directional control valve, the first auxiliary oil port and the second auxiliary oil port are communicated through the first auxiliary oil cavity, the pair of second auxiliary oil cavities, and the pair of pressure oil grooves.
[0010] According to an embodiment, at the first working valve position or the second working valve position, the first auxiliary oil chamber faces one of the pair of pressure oil grooves, one of the pair of second auxiliary oil chambers faces the other pressure oil groove of the pair of pressure oil grooves, and the other second auxiliary oil chamber of the pair of second auxiliary oil chambers faces the outer periphery of the valve core, so that the first auxiliary oil port and the second auxiliary oil port are cut off from each other.
[0011] According to an embodiment, the oil inlet, the first working oil port, and the second working oil port are arranged on the same lateral side of the valve body, and the oil inlet is set to sink relative to the first working oil port and the second working oil port.
[0012] According to an embodiment, the first working oil port and the second working oil port are arranged flush with each other. A one-way valve is installed in the oil inlet, and the one-way valve is oriented to only allow hydraulic oil to flow from the hydraulic oil source into the oil inlet, and the one-way valve does not extend beyond the first working oil port and the second working oil port.
[0013] According to an embodiment, a first pressure oil chamber, a first working oil chamber, a second pressure oil chamber, and a second working oil chamber are formed in the valve body. The first working oil chamber is communicated with the first working oil port, the second working oil chamber is communicated with the second working oil port, and the first pressure oil chamber and the second pressure oil chamber are communicated with the oil inlet; a first working oil groove and a second working oil groove are formed on the valve core; at the first working valve position, the first pressure oil chamber and the first working oil chamber are communicated through the first working oil groove; at the second working valve position, the second pressure oil chamber and the second working oil chamber are communicated through the second working oil groove.
[0014] According to an embodiment, a first oil return chamber and a second oil return chamber are formed in the valve body. The first oil return chamber and the second oil return chamber are communicated with the oil return port; a first oil return groove and a second oil return groove are formed on the valve core; at the first working valve position, the second working oil chamber and the second oil return chamber are communicated through the second oil return groove; at the second working valve position, the first working oil chamber and the first oil return chamber are communicated through the first oil return groove.
[0015] According to an embodiment, a first bypass oil passage is provided between the first working oil port and the first oil return chamber. A plug installed from the first axial side of the valve body blocks the first bypass oil passage or keeps the first bypass oil passage throttled and open.
[0016] According to an embodiment, a second bypass oil passage is provided between the second working oil port and the second oil return chamber. A plug installed from the second axial side of the valve body blocks the second bypass oil passage or keeps the second bypass oil passage throttled and open.
[0017] According to an embodiment, the first auxiliary oil port and the second auxiliary oil port are configured to be interchangeable with each other.
[0018] According to an embodiment, the electromagnetic directional control valve is configured as a wafer valve in a wafer multi-way control valve.
[0019] The electromagnetic directional control valve of the present application has a three-position six-way structure, which realizes the function of unloading in the middle position with a simple structure and is suitable for use in a fixed-displacement pump system. Therefore, it can be widely applied in various mechanical equipment (such as construction machinery, agricultural machinery, etc.). The valve position switching is realized by directly pushing the electromagnet, without the need for a pilot oil source, so the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The foregoing and other aspects of the present application will be more fully understood and appreciated from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0021] Figure 1 is the hydraulic diagram of the electromagnetic directional control valve of the present application;
[0022] Figure 2 is the sectional view of the electromagnetic directional control valve of the present application;
[0023] Figure 3 is the sectional view of the valve body of the electromagnetic directional control valve of the present application;
[0024] Figure 4 is the sectional view of the spool of the electromagnetic directional control valve of the present application;
[0025] Figure 5 is the sectional view of the electromagnetic directional control valve of the present application from another angle. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] The present application generally relates to an electromagnetic directional control valve for a hydraulic system. Figure 1 Schematically shows the hydraulic graphic symbol of the electromagnetic directional control valve of the present application. As Figure 1 shown, the electromagnetic directional control valve has six oil ports: an oil inlet port P, an oil return port T, a first working oil port A, a second working oil port B, an auxiliary oil inlet port P1, and an auxiliary oil return port P2, which are simply referred to as port P, port T, port A, port B, port P1, and port P2. Ports A and B are respectively used to connect to the two end oil ports of the actuator. Port P is used to connect to a hydraulic oil source, such as the output end of a hydraulic pump, especially a fixed-displacement pump. A check valve V1 can be installed at port P so that the high-pressure oil from the hydraulic oil source can only flow towards port P, and reverse flow is prohibited. Port P1 is also connected to this hydraulic oil source. When a check valve V1 is equipped at port P, port P1 is connected to this hydraulic oil source upstream of the check valve V1. Ports T and P2 are connected to the fuel tank.
[0027] The electromagnetic directional control valve has three valve positions, and the valve positions are controlled electromagnetically. In Figure 1In the shown neutral position, the connections between the P port, T port, A port, and B port are all truncated, and the P1 port is connected to the P2 port to achieve the neutral unloading function.
[0028] In the first working valve position, the P port is connected to the A port, the T port is connected to the B port, and the P1 port and the P2 port are truncated. At this time, the hydraulic oil output from the hydraulic oil source is supplied to the actuator through the P port and A port of the electromagnetic directional valve, and the return oil of the actuator returns to the oil tank through the B port and T port of the electromagnetic directional valve, thereby realizing the forward actuation of the actuator.
[0029] In the second working valve position, the P port is connected to the B port, the T port is connected to the A port, and the P1 port and the P2 port are truncated. At this time, the hydraulic oil output from the hydraulic oil source is supplied to the actuator through the P port and B port of the electromagnetic directional valve, and the return oil of the actuator returns to the oil tank through the A port and T port of the electromagnetic directional valve, thereby realizing the reverse actuation of the actuator.
[0030] Figure 2 、 Figure 5 An exemplary structure of the electromagnetic directional valve is shown in, and at this time the electromagnetic directional valve is in the neutral position. The electromagnetic directional valve includes: a valve body 1; a valve core 2, which is axially slidably arranged in the valve body; a first electromagnet 3 and a second electromagnet 4, which are installed at both axial ends of the valve body 1 and are used to drive the valve core 2 to axially slide in the valve body 1 to realize the switching of the valve positions.
[0031] The structures of the first electromagnet 3 and the second electromagnet 4 are well-known in the art and can be standard components, for example, so they will not be described and shown in detail here.
[0032] The exemplary structures of the valve body 1 and the valve core 2 are respectively shown in Figure 3 、 Figure 4 respectively.
[0033] First, referring to Figure 3 , a valve chamber 10 extending axially is formed in the valve body 1 for accommodating the valve core 2. The P port, T port, A port, B port, P1 port, and P2 port are also formed on the valve body 1. Among them, the P port, A port, and B port are arranged on the same transverse side of the valve body 1, and the A port and B port are flush. The P port is located at a position sunken relative to the A port and B port in the valve body 1 between the A port and B port, so as to facilitate the installation of the one-way valve V1 at the P port. Thus, when the one-way valve V1 is installed, the one-way valve V1 will not protrude beyond the positions of the A port and B port, and thus will not interfere with the pipe connection operation of the A port and B port.
[0034] The T port, P1 port, and P2 port can each be arranged on the same transverse side as the P port, A port, and B port, but can also be arranged on other sides of the valve body 1 ( Figure 5 shows an example where the P1 port and P2 port are arranged on other sides of the valve body 1). In Figure 3Shown therein are a T cavity, a P1 cavity (first auxiliary oil cavity), and a P2 cavity (second auxiliary oil cavity) that communicate with a T port, a P1 port, and a P2 port respectively. Among them, the P1 cavity is formed facing the valve chamber 10 at the axial center of the valve chamber 10. The P2 cavity includes a pair of annular oil cavities (both axially spaced from the P1 cavity) facing the valve chamber 10 on both axial sides of the P1 cavity, which can be referred to as the first-side P2 cavity and the second-side P2 cavity. In addition, on the first axial side of the first-side P2 cavity, facing the valve chamber 10, a first pressure oil cavity 10pa, a first working oil cavity 10a, and a first oil return cavity 10t1 are sequentially formed (with the axial distance from the P1 cavity increasing). On the second axial side of the second-side P2 cavity, facing the valve chamber 10, a second pressure oil cavity 10pb, a second working oil cavity 10b, and a second oil return cavity 10t2 are sequentially formed (with the axial distance from the P1 cavity increasing). These cavities are all in the form of annular counterbores facing the valve chamber 10.
[0035] The T cavity is communicated with the first oil return cavity 10t1 through a first-side oil return passage 1t1 and with the second oil return cavity 10t2 through a second-side oil return passage 1t2. The A port is communicated with the first working oil cavity 10a through a first working oil passage 1a. The B port is communicated with the second working oil cavity 10b through a second working oil passage 1b. The P port is communicated with the first pressure oil cavity 10pa through a first pressure oil passage 1pa and with the second pressure oil cavity 10pb through a second pressure oil passage 1pb. These oil passages are all formed in the valve body 1.
[0036] In addition, optionally, a bypass oil passage 11 that communicates the A port with the first oil return cavity 10t1 is further formed in the valve body 1. A plug 12 is installed from the first axial side of the valve body 1. A part of the plug 12 is located in the bypass oil passage 11. The plug 12 can have at least two configurations. In the illustrated configuration, the plug 12 blocks the bypass oil passage 11. In a configuration not shown, the plug 12 is designed to constitute a throttle in the bypass oil passage 11, that is, to maintain a throttled communication between the A port and the first oil return cavity 10t1. The specific configuration of the plug 12 can be selected according to specific needs. The throttle can be realized in the form of an internal throttle passage, an external throttle passage, etc. inside the plug 12.
[0037] Similarly, on the second axial side of the valve body 1, a similar plug and bypass oil passage can be provided, and a specific plug can be selected according to needs to block or throttle the communication between the B port and the second oil return cavity 10t2.
[0038] Next, refer to Figure 4, the main body of the spool 2 is generally cylindrical. An annular oil groove (undercut groove) introduced below is formed on the outer periphery of the spool 2. Specifically, a pair of pressure oil grooves 2p axially spaced from each other are formed in the axial middle, called the first-side pressure oil groove 2p and the second-side pressure oil groove 2p. On the first axial side of the first-side pressure oil groove 2p, a first working oil groove 2a is formed, and a first spool section 21 is interposed between the first-side pressure oil groove 2p and the first working oil groove 2a. On the second axial side of the second-side pressure oil groove 2p, a second working oil groove 2b is formed, and a second spool section 22 is interposed between the second-side pressure oil groove 2p and the second working oil groove 2b. The first spool section 21 and the second spool section 22 cooperate with the valve chamber so that the spool 2 can slide axially in the valve body 1. A plurality of annular grooves axially spaced from each other can be respectively formed on the outer peripheral surfaces of the first spool section 21 and the second spool section 22. After the annular grooves are filled with hydraulic oil, the sliding resistance of the spool 2 can be reduced. On the first axial side of the first working oil groove 2a, a first oil return groove 2t1 axially spaced from the first working oil groove 2a by a first spacer section 23 is formed. On the second axial side of the second working oil groove 2b, a second oil return groove 2tb axially spaced from the second working oil groove 2b by a second spacer section 24 is formed.
[0039] In addition, in order to improve the flow characteristics during valve position switching, radial throttling grooves 2a1, 2a2 can be respectively formed on the first and second axial side end faces of the first working oil groove 2a, radial throttling grooves 2b1, 2b2 can be respectively formed on the first and second axial side end faces of the second working oil groove 2b, a throttling groove 2p1 can be formed on the first axial side end face of the first-side pressure oil groove 2p, and a throttling groove 2p2 can be formed on the second axial side end face of the second-side pressure oil groove 2p.
[0040] Combined Figures 2 - 5 , when neither the first electromagnet 3 nor the second electromagnet 4 is energized, the electromagnetic reversing valve is in the neutral position. The first pressure oil chamber 10pa and the second pressure oil chamber 10pb respectively face the first spool section 21 and the second spool section 22, the first working oil chamber 10a faces the first working oil groove 2a, and the second working oil chamber 10b faces the second working oil groove 2b. The first spacer section 23 and the second spacer section 24 respectively face the wall surface of the valve chamber 10. In this way, the P port, the T port, the A port, and the B port are all cut off. On the other hand, the first axial side part of the P1 chamber is communicated with the first-side P2 chamber through the first-side pressure oil groove 2p, and the second axial side part of the P1 chamber is communicated with the second-side P2 chamber through the second-side pressure oil groove 2p, which makes the P1 port and the P2 port communicate, thereby generating a unloading channel to realize the neutral unloading function.
[0041] In the first working valve position of the electromagnetic reversing valve, the first electromagnet 3 is energized to push the spool 2 towards Figure 2The rightward movement in [description] causes the first working oil chamber 10a and the first pressure oil chamber 10pa to face the first working oil groove 2a, connecting the P port to the A port. The second working oil chamber 10b and the second oil return chamber 10t2 face the second working oil groove 2b, connecting the T port to the B port. The first side P2 chamber faces the first valve core section 21, the P1 chamber faces the first side pressure oil groove 2p, and the P2 chamber faces the second side pressure oil groove 2p, cutting off the P1 port from the P2 port.
[0042] In the second working valve position of the electromagnetic directional valve, the second electromagnet 4 is energized to push the valve core 2 [description] Figure 2 The leftward movement in [description] causes the second working oil chamber 10b and the second pressure oil chamber 10pb to face the second working oil groove 2b, connecting the P port to the B port. The first working oil chamber 10a and the first oil return chamber 10t1 face the first working oil groove 2a, connecting the T port to the A port. The first side P2 chamber faces the first side pressure oil groove 2p, the P1 chamber faces the second side pressure oil groove 2p, and the P2 chamber faces the second valve core section 22, cutting off the P1 port from the P2 port.
[0043] When a plug in the form of a throttle is provided between the A port and the first oil return chamber 10t1, in the second working valve position, the A port and the T port are in throttled communication. When a plug in the form of a throttle is provided between the B port and the second oil return chamber 10t2, in the first working valve position, the B port and the T port are in throttled communication. This throttled communication is beneficial for the working requirements of certain actuators, for example, it can achieve speed control of the actuator in a certain direction.
[0044] Furthermore, as [description] Figure 5 As shown, in the neutral position of the directional valve, the P1 port is connected to the axial inner part of the two pressure oil grooves 2p from one side, and the P2 port is connected to the axial outer part of the two pressure oil grooves 2p from the other side through two branches (a pair of second auxiliary oil chambers). This structure enables the P1 port and the P2 port to be interchangeable. Therefore, the P1 port can be called the first auxiliary oil port, and the P2 port can be called the second auxiliary oil port.
[0045] In addition, in [description] Figure 1 In the pipeline connection mode shown, in the neutral position of the directional valve, the hydraulic oil flows from the P1 port to the P2 port to achieve neutral unloading. However, through a pipeline connection mode different from [description] Figure 1 As shown, the P2 port can be connected to the hydraulic oil source upstream of the one-way valve V1, and the P1 port can be connected to the oil tank. In this way, a reverse neutral flow direction can be achieved, that is, the hydraulic oil flows from the P2 port to the P1 port, also achieving neutral unloading. Figure 1
[0046] Through the interchangeability of the P1 port and the P2 port and the property of reversible flow direction, the flexibility in the application of the directional valve can be improved.
[0047] In addition, in the previously described examples, the control ends on both sides of the electromagnetic directional valve adopt the solenoid actuation method; however, it is also possible to adopt the solenoid actuation method only on one control end of the electromagnetic directional valve and adopt other actuation methods, such as manual, hydraulic, etc., on the other control end.
[0048] The exemplary structure of the electromagnetic directional valve of the present application has been described above. Those skilled in the art can make various adaptive modifications to the specific structures of the various components of the electromagnetic directional valve, especially the specific structures of the valve body and the valve core, based on specific applications.
[0049] The electromagnetic directional valve of the present application has a three-position six-way structure and has a neutral unloading function, which is suitable for use in a fixed-displacement pump system, so it can be widely used in various mechanical equipment. The valve position is switched by direct push of the solenoid, without the need for a pilot oil source, so the cost is low.
[0050] The electromagnetic directional valve of the present application can be made into a wafer valve, so that it can be stacked with other wafer valves (regardless of the valve position switching method) to form a wafer multi-way control valve. Such a wafer multi-way control valve is advantageous for mechanical equipment with complex motion requirements, and can be well applied to, for example, construction machinery, agricultural machinery, etc.
[0051] Although the present application has been described here with reference to specific exemplary embodiments, the scope of the present application is not limited to the details shown. Various modifications can be made to these details without departing from the basic principles of the present application.
Claims
1. An electromagnetic directional valve, comprising: a valve body (1); a spool (2) which is installed in the valve body (1) in a manner capable of axial sliding; and an electromagnet installed at at least one control end of the valve body (1), configured to drive the spool (2) to axially slide in the valve body so that the electromagnetic directional valve realizes valve position switching; characterized in that an oil inlet (P), a first working oil port (A), a second working oil port (B), an oil return port (T), a first auxiliary oil port (P1), and a second auxiliary oil port (P2) are formed on the valve body (1), a pressure oil groove (2p) is formed on the spool (2), wherein, in the neutral position of the electromagnetic directional valve, the first auxiliary oil port (P1) and the second auxiliary oil port (P2) are communicated through the pressure oil groove (2p), so that the first auxiliary oil port (P1) and the second auxiliary oil port (P2) are communicated to form a unloading channel.
2. The electromagnetic directional control valve according to claim 1, wherein In the valve body (1), the first auxiliary oil port (P1) leads to a first auxiliary oil chamber, the second auxiliary oil port (P2) leads to a pair of second auxiliary oil chambers formed on both axial sides of the first auxiliary oil chamber, the pressure oil groove (2p) includes a pair of pressure oil grooves axially spaced from each other, wherein, in the neutral position of the electromagnetic directional valve, the first auxiliary oil port (P1) and the second auxiliary oil port (P2) are communicated through the first auxiliary oil chamber, the pair of second auxiliary oil chambers and the pair of pressure oil grooves.
3. The electromagnetic reversing valve according to claim 2, wherein In the first working valve position or the second working valve position, one of the pair of pressure oil grooves of the first auxiliary oil chamber faces one of the pair of pressure oil grooves, one of the pair of second auxiliary oil chambers faces the other of the pair of pressure oil grooves, and the other of the pair of second auxiliary oil chambers faces the outer periphery of the spool (2), so that the communication between the first auxiliary oil port (P1) and the second auxiliary oil port (P2) is cut off.
4. The electromagnetic directional control valve according to claim 1, characterized in that, The oil inlet (P), the first working oil port (A), and the second working oil port (B) are arranged on the same lateral side of the valve body (1), and the oil inlet (P) is set to sink relative to the first working oil port (A) and the second working oil port (B).
5. The electromagnetic directional control valve according to claim 4, characterized in that, The first working oil port (A) and the second working oil port (B) are arranged flush, a check valve (V1) is installed in the oil inlet (P), the check valve (V1) is oriented to only allow hydraulic oil to flow from a hydraulic oil source into the oil inlet (P), and the check valve (V1) does not protrude beyond the first working oil port (A) and the second working oil port (B).
6. The electromagnetic directional control valve according to any one of claims 1-5, characterized in that, A first pressure oil chamber (10pa), a first working oil chamber (10a), a second pressure oil chamber (10pb), and a second working oil chamber (10b) are formed in the valve body (1). The first working oil chamber (10a) communicates with the first working oil port (A), the second working oil chamber (10b) communicates with the second working oil port (B), and the first pressure oil chamber (10pa) and the second pressure oil chamber (10pb) communicate with the oil inlet port (P); a first working oil groove (2a) and a second working oil groove (2b) are formed on the spool (2); in the first working valve position, the first pressure oil chamber (10pa) and the first working oil chamber (10a) communicate with each other through the first working oil groove (2a); in the second working valve position, the second pressure oil chamber (10pb) and the second working oil chamber (10b) communicate with each other through the second working oil groove (2b).
7. The electromagnetic directional valve according to claim 6, characterized in that, A first oil return chamber (10t1) and a second oil return chamber (10t2) are formed in the valve body (1). The first oil return chamber (10t1) and the second oil return chamber (10t2) communicate with the oil return port (T); a first oil return groove (2t1) and a second oil return groove (2tb) are formed on the spool (2); in the first working valve position, the second working oil chamber (10b) and the second oil return chamber (10t2) communicate with each other through the second oil return groove (2tb); in the second working valve position, the first working oil chamber (10a) and the first oil return chamber (10t1) communicate with each other through the first oil return groove (2t1).
8. The electromagnetic directional control valve according to claim 7, wherein, A first bypass oil passage (11) is provided between the first working oil port (A) and the first oil return chamber (10t1). A plug (12) installed on the first axial side of the valve body (1) blocks the first bypass oil passage (11) or keeps the first bypass oil passage (11) throttled and open; and / or A second bypass oil passage is provided between the second working oil port (B) and the second oil return chamber (10t2). A plug installed on the second axial side of the valve body (1) blocks the second bypass oil passage or keeps the second bypass oil passage throttled and open.
9. The electromagnetic reversing valve according to any one of claims 1-5, characterized in that, The first auxiliary oil port (P1) and the second auxiliary oil port (P2) are configured to be interchangeable with each other.
10. The electromagnetic directional valve according to any one of claims 1-5, characterized in that, The electromagnetic directional control valve is configured as a wafer valve in a wafer - type multi - way control valve.