Three-way proportional valve

Abstract

The three-way proportional valve comprises a valve body (1) which defines a valve chamber (10) and is provided with an oil inlet (P), oil return ports (Ta and Tb), a first working oil cavity (A) and a second working oil cavity (B); the valve core (2) is mounted in the valve chamber (10) and can axially slide to limit a neutral valve position, a first working valve position and a second working valve position of the three-way proportional valve; the hydraulic system is characterized in that the first working oil cavity (A) and the second working oil cavity (B) are communicated to a single working oil duct; the valve body (1) and the valve element (2) are configured in the mode that at the first working valve position, an oil inlet (P) is communicated with the working oil way through a first working oil cavity (A) and a second working oil cavity (B), and oil return openings (Ta and Tb) are cut off; and at the second working valve position, the oil inlet (P) is cut off, and the working oil channel is communicated with the oil return ports (Ta and Tb) through the first working oil cavity (A) and the second working oil cavity (B) respectively.

Description

Technical Field

[0001] This application relates to a three-way proportional valve, specifically a three-way proportional valve with built-in dual flow channels. Background Technology

[0002] In the field of hydraulic oil transportation, directional valves are frequently used. Figure 1 The image shows a standard three-position four-way valve, including port P (inlet), port T (outlet), port A (first working port), and port B (second working port). In the neutral position, all ports are disconnected. In one working position, port P is connected to port A, and port B is connected to port T; in another working position, port P is connected to port B, and port A is connected to port T. It can be seen that in either working position, there are two flow paths within the valve. In some specific applications, such as when used as a pilot valve, only one working port is needed; therefore, one of the working ports is often blocked, for example... Figure 1 As shown, by blocking port B and leaving only port A open as the output port, the three-position four-way valve is converted into a three-position three-way valve. In this case, in any working valve position, only one of the two flow channels inside the valve functions, while the other flow channel is cut off and therefore ineffective, resulting in waste. Utility Model Content

[0003] One object of this application is to provide a three-way proportional valve that can fully utilize the two flow paths within the valve in the working valve position.

[0004] To this end, this application provides a three-way proportional valve in one aspect, comprising: a valve body defining a valve chamber and having an oil inlet, an oil return port, a first working oil chamber, and a second working oil chamber; and a valve core mounted in the valve chamber and axially slidable to define a neutral valve position, a first working valve position, and a second working valve position of the three-way proportional valve; characterized in that the first working oil chamber and the second working oil chamber are connected to a single working oil passage; the valve body and the valve core are configured such that, in the first working valve position, the oil inlet is connected to the working oil passage via the first working oil chamber and the second working oil chamber respectively, and the oil return port is cut off; in the second working valve position, the oil inlet is cut off, and the working oil passage is connected to the oil return port via the first working oil chamber and the second working oil chamber respectively.

[0005] In one feasible exemplary embodiment, the valve body and valve core are further configured such that, in the neutral valve position, the oil inlet, the first working oil chamber, the second working oil chamber, and the oil return port are all cut off; or, in the neutral valve position, the oil inlet, the first working oil chamber, the second working oil chamber, and the oil return port are throttled and connected.

[0006] In one feasible exemplary embodiment, first to fifth oil grooves are sequentially formed on the outer periphery of the valve core, the first to fifth oil grooves dividing the valve core body into first to sixth valve core segments; wherein, grooves are formed on the side of the second valve core segment and the third valve core segment facing the second oil groove, a groove is formed on the side of the fourth valve core segment facing the third oil groove, and a groove is also formed on the side of the fifth valve core segment facing the fifth oil groove.

[0007] In one feasible exemplary embodiment, throttling oil grooves are formed on the side of the second valve core section facing the first oil groove, the side of the third valve core section facing the third oil groove, and the sides of the fourth and fifth valve core sections facing the fourth oil groove 2d, respectively, to achieve the throttling connection in the neutral valve position.

[0008] In one feasible exemplary embodiment, the valve body defines a first working oil port communicating with the first working oil chamber and a second working oil port communicating with the second working oil chamber; the first working oil port and the second working oil port are combined into the working oil passage through an external line.

[0009] In one feasible exemplary embodiment, the flow area of ​​the oil inlet is equal to the sum of the flow areas of the first working oil inlet and the second working oil inlet.

[0010] In one feasible exemplary embodiment, the valve body defines a single working port, and the first working oil chamber and the second working oil chamber are connected to the single working port through an internal circuit. The working port is connected to the working oil passage or constitutes the working oil passage.

[0011] In one feasible exemplary embodiment, the flow area of ​​the oil inlet is equal to the flow area of ​​the single working oil port.

[0012] In one feasible exemplary embodiment, the oil return port includes a first oil return port and a second oil return port, which are connected to each other through an internal channel formed in the valve body.

[0013] In one feasible exemplary embodiment, the three-way proportional valve is configured as a pilot valve to supply control oil pressure to the control end of the main control valve in the hydraulic system.

[0014] According to the three-way proportional valve of this application, two working oil chambers are joined together through external or internal wiring to provide a single working oil passage. In any working valve position, both flow channels within the valve are utilized for hydraulic oil transmission within the valve. Compared to the prior art solution of blocking one working port of a three-position four-way valve, the three-way proportional valve of this application eliminates wasted flow channels. Compared to a standard three-position three-way valve, the three-way proportional valve of this application can provide a larger flow rate by utilizing two parallel flow channels within the valve. Attached Figure Description

[0015] The foregoing and other aspects of this application will be more fully understood and appreciated through the following detailed description with reference to the accompanying drawings, in which:

[0016] Figure 1 This is a hydraulic symbol diagram of a three-position three-way valve modified by blocking one of the working ports of a three-position four-way valve in the existing technology.

[0017] Figure 2 , Figure 3 This is a hydraulic symbol diagram of an exemplary three-way proportional valve of this application;

[0018] Figure 4 This is a cross-sectional view of an exemplary structure of the three-way proportional valve of this application;

[0019] Figure 5 , Figure 6 These are cross-sectional views of the valve body and valve core of the three-way proportional valve of this application, respectively.

[0020] Figure 7 , Figure 8 These are cross-sectional views of the three-way proportional valve of this application at two working valve positions;

[0021] Figure 9 This is a schematic cross-sectional view of a modified three-way proportional valve of this application. Detailed Implementation

[0022] This application generally relates to a three-way proportional valve for controlling the delivery of hydraulic oil, wherein one type of the three-way proportional valve is represented by the hydraulic symbol in... Figure 2 As shown in the image. From Figure 2 As can be seen, this three-way proportional valve is a three-position four-way directional valve with three valve positions and four ports. The three valve positions are: neutral position, first working position, and second working position. The four ports are: P port (inlet), T port (return port), A port (first working port), and B port (second working port). The valve position switching of this three-way proportional valve is achieved by driving the valve core through the control terminals on both sides. Figure 2 In the example shown, the two control terminals of the three-way proportional valve are driven by electromagnets. However, the two control terminals of the three-way proportional valve can also be driven by hydraulics, hydraulics combined with electromagnets, etc. Furthermore, in any working valve position, the flow area of ​​the three-way proportional valve is positively correlated with the driving force of the corresponding control terminal.

[0023] In the neutral valve position of this three-way proportional valve, the ports P, T, A, and B are all cut off.

[0024] In the first working valve position, port P is connected to both ports A and B, while port T is cut off.

[0025] In the second working valve position, port T is connected to both ports A and B, while port P is cut off.

[0026] Furthermore, ports A and B can be connected via an external line to form a single working oil passage for supplying hydraulic oil to the same working device. For example, hydraulic oil can be supplied to a hydraulic actuator through the single working oil passage, or the three-way proportional valve can act as a pilot valve to supply control oil pressure to a control terminal of the main control valve of the hydraulic system.

[0027] According to a modification, such as Figure 3 As shown, in Figure 2 Based on the three-way proportional valve shown, the neutral valve position is modified to allow throttling and connection between ports P, T, A, and B. For Figure 3 The modified version shown also connects ports A and B through an external line to form a single working oil passage.

[0028] The following reference Figures 4-8 describe Figure 2 An exemplary structure of the three-way proportional valve shown is illustrated. Figure 4 The image shows the neutral position of the three-way proportional valve. Figure 7 The first working position of the three-way proportional valve is shown in the figure. Figure 8 The second working position of the three-way proportional valve is shown in the figure.

[0029] See Figure 4 The three-way proportional valve includes a valve body 1 and a single valve core 2 arranged in the valve body 1. The valve position is switched by controlling the position of the valve core 2 in the valve body 1.

[0030] See Figure 5 The valve body 1 defines an axially extending valve chamber 10 for axially slidingly mounting the valve core 2 within the valve chamber 10. The valve body 1 forms a structure extending axially from a first side along the valve chamber 10. Figure 5 (middle left) towards the second side of the axis ( Figure 5 The valve body 1 is configured in the following order (right side): Ta cavity (first return oil cavity), P cavity (inlet oil cavity), A cavity (first working oil cavity), B cavity (second working oil cavity), and Tb cavity (second return oil cavity). Cavities P, A, and B are connected to ports P, A, and B, respectively. Port T is divided into two return ports: Ta and Tb. The Ta and Tb cavities in valve body 1 are connected to ports Ta and Tb, respectively, and are interconnected within valve body 1 via internal channels. The naming convention for the aforementioned ports and cavities is conventional in the art. In the following description, mentioning connection (or disconnection) to a particular oil cavity means also connection (or disconnection) to the corresponding oil port.

[0031] See Figure 6 On the outer periphery of valve core 2, along the first side from the axial direction ( Figure 6 From the left side of the middle to the second side of the axis ( Figure 6 Looking from the right side, the first to fifth oil grooves (cutting grooves) 2a, 2b, 2c, 2d, and 2e are formed sequentially. These oil grooves divide the body of the valve core 2 from the first axial side to the second axial side into the first valve core section 21, the second valve core section 22, the third valve core section 23, the fourth valve core section 24, the fifth valve core section 25, and the sixth valve core section 26.

[0032] Back Figure 4 Ports A and B, connected by the schematically drawn external circuit Lab, will form a single working oil passage.

[0033] It should be noted that hydraulic valve ports have prescribed standard forms and dimensions. Selecting the appropriate pipelines to form the external circuit Lab according to the specific forms and dimensions of ports A and B of the three-way proportional valve in this application is easy for those skilled in the art.

[0034] See Figure 4 and combined Figure 5 , Figure 6 In the neutral position of the three-way proportional valve, the first oil groove 2a faces the Ta chamber, the second oil groove 2b faces the A chamber, the third oil groove 2c faces the P chamber, the fourth oil groove 2d faces the B chamber, and the fifth oil groove 2e faces the Tb chamber. Each oil chamber is separated by the second valve core section 22, the third valve core section 23, the fourth valve core section 24, and the fifth valve core section 25 of the valve core 2. In this way, all oil ports of the three-way proportional valve are disconnected.

[0035] See Figure 7 and combined Figure 5 , Figure 6 The valve core 2 is driven from the first axial side to the second axial side to achieve the first working valve position of the three-way proportional valve. In the first working valve position, the second oil groove 2b connects the A chamber to the P chamber, and the third oil groove 2c connects the B chamber to the P chamber. The second valve core section 22 isolates the Ta chamber from the A chamber, and the fifth valve core section 25 isolates the Tb chamber from the B chamber. In this way, the P port of the three-way proportional valve is connected to the A port and the B port respectively through two flow channels existing in the valve at this time (i.e., the flow channel from the P port to the A port and the flow channel from the P port to the B port). Hydraulic oil can enter the valve from the P port of the three-way proportional valve, and the hydraulic oil from the P port can flow to the A port and the B port. Then, the hydraulic oil enters a single working oil channel through the external line Lab at the A port and is output.

[0036] See Figure 8 and combined Figure 5 , Figure 6The valve core 2 is driven from the second axial side to the first axial side to achieve the second working valve position of the three-way proportional valve. In the second working valve position, the second oil groove 2b connects the A chamber to the Ta chamber, and the fifth oil groove 2e connects the B chamber to the Tb chamber. The third valve core section 23 and the fourth valve core section 24 respectively isolate the P chamber from the A chamber and the B chamber. In this way, the Ta port and Tb port of the three-way proportional valve are connected to the A port and the B port respectively through two flow channels existing in the valve at this time (i.e., the flow channel from the Ta port to the A port, and the flow channel from the Tb port to the B port). The hydraulic oil returning through the single working oil channel enters the A port and the B port respectively through the external line Lab, and then the hydraulic oil in the A port and the B port can flow to the Ta port and the Tb port respectively. Of course, there may also be flow in the internal line between the Ta port and the Tb port inside the valve body 1.

[0037] Back Figure 6 As can be seen, grooves 3 are formed on the side of the second valve core section 22 and the third valve core section 23 facing the second oil groove 2b, respectively. Grooves 3 are also formed on the side of the fourth valve core section 24 facing the third oil groove 2c, and grooves 3 are also formed on the side of the fifth valve core section 25 facing the fifth oil groove 2e. These grooves are beneficial for suppressing flow rate and pressure fluctuations when the valve position is switched.

[0038] Each groove 3 is formed between adjacent oil grooves and valve core sections. The groove 3 has the largest flow area at the interface between the oil groove and the valve core section, and the flow area gradually decreases both as it extends towards the oil groove and as it extends towards the valve core section. This allows for smooth flow rate and pressure changes during valve position switching.

[0039] It can be understood that by forming throttling oil grooves similar to oil grooves 3 on the side of the second valve core section 22 facing the first oil groove 2a, the side of the third valve core section 23 facing the third oil groove 2c, and the sides of the fourth valve core section 24 and the fifth valve core section 25 each facing the fourth oil groove 2d, or even by forming the grooves 3 on the second valve core section 22, the third valve core section 23, the fourth valve core section 24, and the fifth valve core section 25 to have an axial width that runs through each third valve core section, it is possible to... Figure 2 The configuration of the three-way proportional valve shown has been modified to Figure 3 The configuration shown achieves throttling connection between ports P, T, A, and B in a neutral position.

[0040] Based on the principles of this application, those skilled in the art can modify the three-way proportional valve described above. For example, in Figure 9 In the modified version shown, an internal circuit is formed in the valve body 1 that merges chambers A and B into a single working port A'. Thus, the single working port A' is equivalent to... Figures 4-8In the three-way proportional valve, the combination of ports A and B allows the single working port A' to connect to or form a single working oil passage. In the first working position, port P of the three-way proportional valve is connected to port A' through two flow paths existing within the valve (i.e., the flow path from port P through chamber P and chamber A to port A', and the flow path from port P through chamber P and chamber B to port A'). In the second working position, ports Ta and Tb of the three-way proportional valve are connected to port A' through two flow paths existing within the valve (i.e., the flow path from port Ta through chamber P and chamber A to port A', and the flow path from port Tb through chamber P and chamber B to port A').

[0041] Figure 9 Other aspects of the modification shown are similar to Figures 4-8 The three-way proportional valves described herein are the same as or similar to those described elsewhere, and will not be described again here.

[0042] Furthermore, in Figures 4-8 The mounting interface of the three-way proportional valve shown can have ports P, A, B, Ta, and Tb. Considering that port P connects to ports A and B via two internal flow channels, this application proposes to increase the flow area of ​​port P on the mounting interface of the three-way proportional valve to reduce the pressure drop from port P to ports A and B in the first working valve position. According to one design scheme, the flow area of ​​port P is set as the sum of the flow areas of ports A and B.

[0043] exist Figure 9 The installation interface of the three-way proportional valve shown can have ports P, A', Ta, and Tb. The flow area of ​​port P can be set to be equal to that of port A.

[0044] According to the three-way proportional valve of this application, two internal flow channels existing in parallel in any working valve position are simultaneously used to deliver hydraulic oil. Hydraulic oil is output or returned through a single working oil passage. Therefore, compared with the prior art solution of blocking one working port of a three-position four-way valve, the three-way proportional valve of this application does not waste flow channels. Compared with a standard three-position three-way valve, the three-way proportional valve of this application can provide a larger flow rate by utilizing the two parallel flow channels within the valve.

[0045] While this application has been described herein with reference to specific exemplary embodiments, the scope of this application is not limited to the details shown. Various modifications may be made to these details without departing from the basic principles of this application.

Claims

1. A three-way proportional valve, comprising: Valve body (1), which defines valve chamber (10) and is formed with oil inlet (P), oil return port (Ta, Tb), first working oil chamber (A), and second working oil chamber (B); and The valve core (2) is installed in the valve chamber (10) and is axially slidable to define the neutral valve position, the first working valve position and the second working valve position of the three-way proportional valve; The first working oil chamber (A) and the second working oil chamber (B) are connected to a single working oil passage; The valve body (1) and valve core (2) are configured such that, in the first working valve position, the oil inlet (P) is connected to the working oil passage via the first working oil chamber (A) and the second working oil chamber (B) respectively, and the oil return port (Ta, Tb) is cut off; in the second working valve position, the oil inlet (P) is cut off, and the working oil passage is connected to the oil return port (Ta, Tb) via the first working oil chamber (A) and the second working oil chamber (B) respectively.

2. The three-way proportional valve as described in claim 1, characterized in that, The valve body (1) and valve core (2) are further configured such that, in the neutral valve position, the oil inlet (P), the first working oil chamber (A), the second working oil chamber (B), and the oil return port (Ta, Tb) are all cut off; or, in the neutral valve position, the oil inlet (P), the first working oil chamber (A), the second working oil chamber (B), and the oil return port (Ta, Tb) are throttled and connected.

3. The three-way proportional valve as described in claim 2, characterized in that, First to fifth oil grooves are formed sequentially on the outer periphery of the valve core (2), which divide the valve core (2) body into first to sixth valve core segments; wherein, grooves (3) are formed on the side of the second valve core segment (22) and the third valve core segment (23) facing the second oil groove (2b), grooves (3) are formed on the side of the fourth valve core segment (24) facing the third oil groove (2c), and grooves (3) are also formed on the side of the fifth valve core segment (25) facing the fifth oil groove (2e).

4. The three-way proportional valve as described in claim 3, characterized in that, Throttling oil grooves are formed on the side of the second valve core section (22) facing the first oil groove (2a), the side of the third valve core section (23) facing the third oil groove (2c), and the side of the fourth valve core section (24) and the fifth valve core section (25) facing the fourth oil groove (2d), respectively, so as to realize the throttling connection in the neutral valve position.

5. The three-way proportional valve as described in claim 1, characterized in that, The valve body (1) defines a first working oil port communicating with the first working oil chamber (A) and a second working oil port communicating with the second working oil chamber (B); the first working oil port and the second working oil port are connected to the working oil passage through an external line (Lab).

6. The three-way proportional valve as described in claim 5, characterized in that, The flow area of ​​the oil inlet (P) is equal to the sum of the flow areas of the first working oil inlet and the second working oil inlet.

7. The three-way proportional valve as described in claim 1, characterized in that, The valve body (1) defines a single working port (A'), and the first working oil chamber (A) and the second working oil chamber (B) are connected to the single working port (A') through an internal circuit. The working port is connected to the working oil passage or constitutes the working oil passage.

8. The three-way proportional valve as described in claim 7, characterized in that, The flow area of ​​the oil inlet (P) is equal to the flow area of ​​the single working oil inlet (A').

9. The three-way proportional valve as described in any one of claims 1-8, characterized in that, The oil return ports (Ta, Tb) include a first oil return port (Ta) and a second oil return port (Tb), which are connected to each other through an internal channel formed in the valve body (1).

10. The three-way proportional valve as described in any one of claims 1-8, characterized in that, The three-way proportional valve is configured as a pilot valve to supply control oil pressure to the control terminal of the main control valve in the hydraulic system.

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