A position monitoring structure and method for an oil distribution valve

Abstract

The present invention belongs to the technical field of oil-dividing sliding valves, and discloses a position monitoring structure and method for an oil-dividing valve, comprising: a housing 1, a first oil-dividing sliding valve 2, a second oil-dividing sliding valve 3, a throttle valve 4 and a proximity switch 5; wherein, the first oil-dividing sliding valve 2 serves as the monitored oil-dividing sliding valve; the first oil-dividing sliding valve 2 comprises: a first oil-dividing sliding valve valve sleeve 2a and a first oil-dividing sliding valve valve core 2b, the second oil-dividing sliding valve 3 comprises: a second oil-dividing sliding valve valve sleeve 3a and a second oil-dividing sliding valve valve core 3b, and the proximity switch 5 comprises: a sensing switch part 5a of the proximity switch and a detected part 5b of the proximity switch; by converting the oil-dividing sliding valve position signal into a pressure signal, driving the secondary device to move, thereby realizing position monitoring of the oil-dividing sliding valve.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil distribution sliding valves, and in particular relates to a position monitoring structure and method for an oil distribution valve. Background Art

[0002] In mechanical hydraulic systems, oil distribution spool valves are widely used as hydraulic amplification components, converting mechanical signals into hydraulic signals. For these critical oil distribution spool valves, it's often necessary to monitor their displacement to determine whether they're functioning properly and to proactively intervene.

[0003] It's often necessary to monitor the position of key oil distribution valves to ensure the system is operating normally. Existing oil distribution valve position monitoring typically uses displacement sensors or proximity switches to determine the position of the valve. The former is complex, while the latter suffers from low accuracy. High-precision oil distribution valve position monitoring is difficult to implement in tight assembly spaces, with small travel distances. Summary of the Invention

[0004] The present invention proposes a position monitoring structure and method for an oil distribution valve, which converts the position signal of the oil distribution slide valve into a pressure signal to drive the movement of a secondary device to achieve position monitoring of the oil distribution slide valve.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions to achieve it.

[0006] Technical solution 1:

[0007] A position monitoring structure for an oil distribution valve includes a housing 1, a first oil distribution slide valve 2, a second oil distribution slide valve 3, a throttle valve 4, and a proximity switch 5. The first oil distribution slide valve 2 serves as the monitored oil distribution slide valve. The first oil distribution slide valve 2 includes a first oil distribution slide valve sleeve 2a and a first oil distribution slide valve spool 2b. The second oil distribution slide valve 3 includes a second oil distribution slide valve sleeve 3a and a second oil distribution slide valve spool 3b. The proximity switch 5 includes a proximity switch sensing portion 5a and a detected portion 5b.

[0008] The first oil distribution slide valve 2 is installed in the inner cavity of the housing 1. The first oil distribution slide valve window area is controlled by moving the first oil distribution slide valve spool 2b to change the control pressure PX to the second oil distribution slide valve;

[0009] The second oil distribution slide valve 3 is installed in the inner cavity of the housing 1. The upper end of the second oil distribution slide valve core 3b receives the control pressure PX from the first oil distribution slide valve, and the lower end receives the fixed pressure P2;

[0010] The throttle valve 4 is arranged in the second oil distribution slide valve core 3b, and the detected part 5b of the proximity switch is arranged in the second oil distribution slide valve core (3b), so that the detected part 5b of the proximity switch moves in real time with the second oil distribution slide valve core (3b); the sensing switch part 5a of the proximity switch is fixed relative to the housing.

[0011] The characteristics and further improvements of the technical solution 1 of the present invention are:

[0012] (1) The first oil distribution sliding valve and the second oil distribution sliding valve are cylindrical structures.

[0013] (2) At least one sealing ring is provided between the first oil distribution sliding valve and the second oil distribution sliding valve and the inner cavity of the housing.

[0014] (3) There is at least one oil circuit communicating between the first oil distribution sliding valve and the second oil distribution sliding valve for transmitting a position signal of the first oil distribution sliding valve.

[0015] (4) At least one sealing ring is provided between the second oil distribution sliding valve core and the second oil distribution sliding valve sleeve.

[0016] (5) The detected part of the proximity switch is used in conjunction with the inductive switch part of the proximity switch. When the distance between the detected part and the inductive switch is greater than the disconnection distance of the proximity switch, the switch is disconnected. When the distance between the detected part and the inductive switch is less than the connection distance of the proximity switch, the switch is connected.

[0017] Technical solution 2:

[0018] A method for monitoring the position of an oil distribution valve, the method being applied to the device described in technical solution 1, the method comprising:

[0019] When the first oil distribution slide valve spool 2b does not move, the oil passage PPX to the second oil distribution slide valve is closed. When the first oil distribution slide valve spool 2b moves to the set position, the control pressure PX to the second oil distribution slide valve is equal to the high-pressure oil pressure P1.

[0020] When the first oil distribution sliding valve core 2b moves to the set position, PX = P1 > P2, the second oil distribution sliding valve core 3b will move downward under the action of the pressure difference between the upper and lower ends;

[0021] When the second oil distribution slide valve spool 3b moves to the set position, the oil path PPX leading to the second oil distribution slide valve communicates with the system low-pressure oil path through the throttle valve 4. When the PX pressure drops to PX=P2, the second oil distribution slide valve spool 3b stops moving.

[0022] When the detected part of the proximity switch moves to a given position along with the valve core of the second oil distribution sliding valve, the proximity switch will switch the signal, indicating that the valve core of the first oil distribution sliding valve moves to the set position, thereby achieving the purpose of position monitoring.

[0023] The characteristics and further improvements of the second technical solution of the present invention are:

[0024] (1) The pressure PX leading to the second oil distribution slide valve, P3≤PX≤P1, P3 is the system low pressure, P1 is the high pressure oil pressure.

[0025] (2) The lower end of the second oil distribution sliding valve core 3b receives a fixed pressure P2, P3<P2<P1, P3 is the system low pressure, and P1 is the high pressure oil pressure.

[0026] The present invention utilizes the movement of the oil distribution slide valve to change the size of the throttle area through the relative movement between the valve core and the valve sleeve to control the outlet fluid pressure, thereby converting its position information into pressure information; then, through the position change of the secondary device, the position monitoring function of the high-precision oil distribution slide valve is realized to ensure the reliable operation of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a position monitoring structure of an oil distribution valve provided in an embodiment of the present invention;

[0028] Among them: 1-housing, 2a-first oil distribution sliding valve sleeve, 2b-first oil distribution sliding valve core, 3a-second oil distribution sliding valve sleeve, 3b-second oil distribution sliding valve core, 4-throttle valve, 5a-sensing switch part of the proximity switch, 5b-detected part of the proximity switch, 6-first sealing ring, 7-second sealing ring, 8-third sealing ring. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0030] As the control accuracy and reliability requirements for hydraulic machinery continue to increase, the functions of oil distributor spools will become more integrated, and their structures will become more compact and complex. For oil distributor spool assemblies requiring precise position control, existing structures that directly monitor the movement of the oil distributor spool using sensors are no longer suitable and cannot meet the high-precision control requirements. The present invention differs from previous position monitoring methods by converting the oil distributor spool position signal into a pressure signal, which drives the movement of a secondary device to achieve position monitoring of the oil distributor spool.

[0031] The embodiment of the present invention provides a position monitoring structure of an oil distribution valve, such as Figure 1As shown, it includes a housing, a first oil-dividing sliding valve assembly (composed of a valve sleeve and a valve core), a second oil-dividing sliding valve (composed of a valve sleeve and a valve core), a throttle valve and a proximity switch (composed of a detected part and an induction switch); the first oil-dividing sliding valve assembly is installed in the inner cavity of the housing, and the window area of ​​the oil-dividing sliding valve is controlled by moving the valve core to change the pressure PX (P3 (system low pressure) ≤ PX ≤ P1 (high pressure oil pressure)) leading to the second oil-dividing sliding valve. When the valve core does not move, the PX oil circuit is closed. When the valve core moves to the set position, PX is equal to P1. The second oil-dividing sliding valve assembly is installed in the inner cavity of the housing. The upper end of the valve core receives the control pressure PX from the first oil-dividing sliding valve, and the lower end receives the fixed pressure P2 (P3<P2<P1). When the valve core of the first oil-dividing sliding valve moves to When in the set position, PX=P1>P2, and the spool of the second oil distribution slide valve will move downward under the action of the pressure difference between the upper and lower ends; the throttle valve is arranged in the spool of the second oil distribution slide valve, and when the spool of the second oil distribution slide valve moves to the set position, the PX oil circuit communicates with the P3 oil circuit through the throttle valve, and when the PX pressure decreases until PX=P2, the spool stops moving; the detected part of the proximity switch is arranged in the spool of the second oil distribution slide valve, so that the detected part moves in real time with the spool of the second oil distribution slide valve; the sensing switch part of the proximity switch is fixed relative to the housing, and when the detected part moves to a given position with the spool of the second oil distribution slide valve, the switch will switch the signal, indicating that the spool of the first oil distribution slide valve has moved to the set position, thereby achieving the purpose of position monitoring.

[0032] Furthermore, the first oil distribution sliding valve and the second oil distribution sliding valve are cylindrical structures;

[0033] Furthermore, at least one sealing ring is provided between the first oil distribution sliding valve, the second oil distribution sliding valve and the inner cavity of the housing respectively;

[0034] Furthermore, at least one oil passage is in communication between the first oil distribution slide valve and the second oil distribution slide valve for transmitting a position signal of the first oil distribution slide valve;

[0035] Furthermore, at least one sealing ring is provided between the valve core and the valve sleeve of the second oil distribution sliding valve;

[0036] Furthermore, the detected part of the proximity switch is used in conjunction with an inductive switch. When the distance L between the detected part and the inductive switch is greater than the disconnection distance X1 of the proximity switch, the switch is disconnected. When the distance L between the detected part and the inductive switch is less than the connection distance X2 of the proximity switch, the switch is connected.

[0037] Furthermore, the housing is a high-pressure slide valve housing.

[0038] The present invention provides a position monitoring structure for an oil distribution sliding valve, which can be applied to monitoring the speed control function of a hydraulic mechanical device.

[0039] In order to ensure the reliability of hydraulic mechanical devices, it is usually necessary to limit the maximum speed allowed for the rotor part of the system, that is, the overspeed limit. In view of the huge harm of overspeed, the overspeed protection system is considered to be one of the most critical protection systems of the control system. A typical mechanical hydraulic overspeed protection system uses centrifugal flyweights to sense the speed and connect with the hydraulic actuator. By controlling the flow area of ​​the oil distribution slide valve, the system input energy (such as oil supply) is changed, thereby suppressing the overspeed of the hydraulic mechanical system. With the application of the concept of health management, considering the importance of the overspeed protection system, a monitoring speed point is usually set before the hydraulic mechanical system enters the overspeed speed to detect whether the overspeed protection device is operating normally.

[0040] When the system speed is lower than the set monitoring speed, the first oil distribution sliding valve spool 2 (b) does not move and the PPX oil circuit is closed;

[0041] When the system speed reaches the set monitoring speed, the spool 2(b) of the first oil-dividing slide valve moves to the specified position, controls the oil-dividing slide valve window 1 to open, PX=P1, and leads to the upper chamber of the spool 3(b) of the second oil-dividing slide valve; at this time, the pressure P2 in the lower chamber of the spool 3(b) of the second oil-dividing slide valve is less than P1, the spool 3(b) will move downward, and the detected part 5(b) of the proximity switch will move downward accordingly (away from the sensing switch 5(a) part) until the second oil-dividing slide valve window opens; at this time, PX will communicate with the system low-pressure oil P3 through the throttle valve 4 until PX=P2, the spool 3(b) stops moving, the distance between the sensing switch 5(a) of the proximity switch and the detected part 5(b) is greater than the disconnection distance of the proximity switch, the switch signal is cut off, and the monitoring of the working status of the over-speed protection device is realized.

[0042] When the system speed continues to rise and reaches the speed limit, the first oil distribution slide valve core 2 (b) moves to the oil release position, controlling the oil distribution slide valve window 2 to open, and P4 (system high pressure) communicates with P5 (system low pressure). The system oil supply is reduced through pressure control to achieve the purpose of overspeed limitation.

[0043] The present invention utilizes the movement of the oil distribution slide valve to change the size of the throttle area through the relative movement between the valve core and the valve sleeve to control the outlet fluid pressure, thereby converting its position information into pressure information; then, through the position change of the secondary device, the position monitoring function of the high-precision oil distribution slide valve is realized to ensure the reliable operation of the hydraulic system.

Claims

1. A position monitoring structure for an oil distribution valve, characterized in that: The structure comprises: a housing (1), a first oil distribution slide valve (2), a second oil distribution slide valve (3), a throttle valve (4) and a proximity switch (5); wherein the first oil distribution slide valve (2) serves as a monitored oil distribution slide valve; the first oil distribution slide valve (2) comprises: a first oil distribution slide valve sleeve (2a) and a first oil distribution slide valve core (2b); the second oil distribution slide valve (3) comprises: a second oil distribution slide valve sleeve (3a) and a second oil distribution slide valve core (3b); and the proximity switch (5) comprises: a sensing switch part (5a) and a detected part (5b); The first oil distribution slide valve (2) is installed in the inner cavity of the housing (1), and the control pressure PX to the second oil distribution slide valve is changed by controlling the window area of ​​the first oil distribution slide valve through the movement of the first oil distribution slide valve spool (2b); The second oil distribution slide valve (3) is installed in the inner cavity of the housing (1), and the upper end of the second oil distribution slide valve core (3b) receives the control pressure PX from the first oil distribution slide valve, and the lower end receives the fixed pressure P2; The throttle valve (4) is arranged in the second oil distribution slide valve core (3b), and the detected portion (5b) of the proximity switch is arranged in the second oil distribution slide valve core (3b), so that the detected portion (5b) of the proximity switch moves in real time with the second oil distribution slide valve core (3b); the sensing switch portion (5a) of the proximity switch is fixed relative to the housing (1); When the first oil distribution slide valve core (2b) does not move, the oil passage PPX leading to the second oil distribution slide valve is closed; when the first oil distribution slide valve core (2b) moves to a set position, the control pressure PX leading to the second oil distribution slide valve is equal to the high-pressure oil pressure P1; When the first oil distribution sliding valve core (2b) moves to the set position, PX=P1>P2, the second oil distribution sliding valve core (3b) moves downward under the action of the pressure difference between the upper and lower ends; P2 is the fixed pressure received by the lower end of the second oil distribution sliding valve core (3b); When the second oil distribution slide valve core (3b) moves to a set position, the oil circuit PPX leading to the second oil distribution slide valve communicates with the system low-pressure oil circuit through the throttle valve (4); when the PX pressure drops to PX=P2, the second oil distribution slide valve core (3b) stops moving; When the detected part of the proximity switch moves to a given position along with the valve core of the second oil distribution sliding valve, the proximity switch will switch the signal, indicating that the valve core of the first oil distribution sliding valve moves to the set position, thereby achieving the purpose of position monitoring.

2. The oil distribution valve position monitoring structure according to claim 1, characterized in that: The first oil distribution sliding valve and the second oil distribution sliding valve are cylindrical structures.

3. The oil distribution valve position monitoring structure according to claim 1, characterized in that: At least one sealing ring is provided between the first oil distribution sliding valve, the second oil distribution sliding valve and the inner cavity of the housing respectively.

4. The oil distribution valve position monitoring structure according to claim 1, characterized in that: At least one oil passage is in communication between the first oil distribution sliding valve and the second oil distribution sliding valve for transmitting a position signal of the first oil distribution sliding valve.

5. The oil distribution valve position monitoring structure according to claim 1, characterized in that: At least one sealing ring is provided between the second oil distribution sliding valve core and the second oil distribution sliding valve sleeve.

6. The oil distribution valve position monitoring structure according to claim 1, characterized in that: The sensing switch part of the proximity switch is used in conjunction with the detected part of the proximity switch. When the distance between the detected part and the sensing switch is greater than the disconnection distance of the proximity switch, the switch is disconnected. When the distance between the detected part and the sensing switch is less than the connection distance of the proximity switch, the switch is connected.

7. The oil distribution valve position monitoring structure according to claim 1, characterized in that: The pressure PX leading to the second oil distribution sliding valve, P3≤PX≤P1, P3 is the system low pressure, P1 is the high pressure oil pressure.

8. The oil distribution valve position monitoring structure according to claim 1, characterized in that: The lower end of the second oil distribution sliding valve core (3b) receives a fixed pressure P2, P3<P2<P1, P3 is the system low pressure, and P1 is the high pressure oil pressure.

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