An air tightness detection device for a pilot valve of a valve positioner

Abstract

The utility model provides an air tightness detection device for a pilot valve of a valve positioner, comprising: a test bench and a first liquid storage tank, a second liquid storage tank, a positioning frame and a positioning cylinder arranged on the test bench in sequence; the first liquid storage tank is arranged on the test bench through a lifting mechanism; the second liquid storage tank is fixed on the test bench through a back plate, the top is connected to a pressurizing device through an air inlet pipe, the bottom is connected to the first liquid storage tank through a conduit, and the side is connected to a joint of a test cavity through a pressure transmission pipe; the positioning frame has a baffle, and the driving end of the positioning cylinder has a push block pointing in the direction of the baffle; an auxiliary device for screwing the joint into the test cavity interface is arranged on one side of the positioning frame. The utility model can automatically adjust the position of the pilot valve and automatically install the test interface, the interface is well sealed, and the test is accurate and efficient.

Description

Technical Field

[0001] The utility model relates to the technical field of valve positioner detection, in particular to an airtight detection device for a pilot valve of a valve positioner. Background Art

[0002] The pilot valve plays an important role in the valve positioner. Its main function is to control the flow direction and pressure of the oil in the system, ensure that other valves and hydraulic components can work normally, and provide key support for the normal operation of the entire valve positioner.

[0003] For pilot valves, air tightness testing is an important step to ensure the normal operation and stable performance of the pilot valve. During operation, the pilot valve needs to ensure the stability of the pressure in the control chamber to prevent gas or liquid leakage. If there is an air tightness problem with the pilot valve, it will cause pressure fluctuations in the control chamber, affecting the normal movement of the valve core, and further affecting the switching state and control accuracy of the main valve.

[0004] The air tightness detection device works based on the principle of air pressure change. During the detection process, the device is first connected to the cavity of the product to be detected and sealed, and then a certain pressure of gas is applied to the test cavity through a pressure source. Subsequently, the pressure change in the test cavity is monitored by a sensor. If there is a leak in the detected cavity, the pressure will drop and its sealing performance will be unqualified. When the air tightness of the pilot valve is detected, if it is necessary to install a sensor in the cavity and complete the connection and test of the device every time, the test efficiency is low. The prior art provides an intelligent detection device that uses liquid sealing and pressurization to detect the air tightness of the pilot valve. The device includes: a bottom plate for placing the pilot valve; a U-shaped square tube with one end sealed, liquid inside, the other end connected to the pressure source, and the side connected to the pilot valve cavity for pressurizing the test cavity; a control mechanism for limiting the displacement of the pilot valve transmission rod. When the pressure source applies a certain pressure of gas to the test cavity, it can be judged from the change of the liquid level whether there is a leak in the test cavity.

[0005] This prior art still has many manual operation steps, and the pilot valve position needs to be manually placed and adjusted, and the test interface needs to be manually installed and connected to the side of the U-shaped square tube. When used to test pilot valves of different specifications, the positioning and interface need to be adjusted, and these adjustments limit the efficiency of the test.

[0006] Therefore, it is necessary to improve the existing technology. Utility Model Content

[0007] The utility model provides an air tightness detection device for a pilot valve of a valve positioner, which is used to solve the above problem.

[0008] A technical solution adopted by the utility model is: to provide an air tightness detection device for a pilot valve of a valve positioner, comprising: a test bench and a first liquid storage tank, a second liquid storage tank, a positioning frame and a positioning cylinder arranged on the test bench in sequence;

[0009] The first liquid storage tank is arranged on the test bench through a lifting mechanism;

[0010] The second liquid storage tank is fixed on the test bench through a back plate, the top is connected to the pressurizing device through an air inlet pipe, the bottom is connected to the first liquid storage tank through a conduit, and the side is connected to the joint of the test cavity through a pressure transmission pipe, and the pressure of the test cavity is created by raising the first liquid storage tank or inputting gas into the second liquid storage tank;

[0011] The positioning frame has a baffle, and the driving end of the positioning cylinder has a push block pointing in the direction of the baffle, so as to push the pilot valve placed on the positioning frame to the baffle and fix it;

[0012] An auxiliary device for screwing the joint into the test cavity interface is provided on one side of the positioning frame. When the auxiliary device completes the installation of the joint, the other end of the pressure transmission pipe is connected to the joint to perform air tightness testing;

[0013] The airtightness test is divided into two steps. The first step is to raise the first liquid storage tank, use the liquid pressure to pressurize the test cavity, and observe the changes in the liquid level of the second liquid storage tank. In the second step, the pressurizing device outputs gas, uses the gas pressure to pressurize the test cavity again, and observes the changes in the liquid level of the second liquid storage tank. When the pressure in the test cavity increases and the liquid level in the second liquid storage tank stabilizes, the air tightness of the pilot valve is normal.

[0014] Furthermore, the positioning frame has an arc-shaped groove, which is convenient for stably placing the pilot valve.

[0015] Furthermore, a guide groove is provided on the arc-shaped groove to facilitate the placement of the connector on the other side of the pilot valve, while also ensuring that the connector of the test cavity is located directly above.

[0016] Furthermore, the push block is a U-shaped structure with an opening to the left, which can both abut against the pilot valve housing and limit the transmission rod of the pilot valve.

[0017] Furthermore, the auxiliary device includes an auxiliary motor, which is arranged on the test bench through an auxiliary lifting mechanism, and a detachable screwdriver bit is arranged at the driving end thereof, pointing to the joint directly below.

[0018] Furthermore, a sensor is provided on one side of the auxiliary motor, and the distance between the screwdriver bit and the housing of the pilot valve below is determined by the sensor, thereby determining the downward stroke of the auxiliary motor.

[0019] The beneficial effects of the air tightness detection device of the valve positioner pilot valve of the utility model are:

[0020] 1. Design positioning frame and positioning cylinder to position and fix the pilot valve, which can ensure the stability of the pilot valve position and the test cavity without manual adjustment;

[0021] 2. An auxiliary device is set on one side of the positioning frame to screw the corresponding joint into the test chamber interface. There is no need to manually install the test interface. The interface installation consistency is high and the sealing condition is better. After that, you only need to connect the other end of the pressure transmission tube to the joint to carry out the test, which is conducive to improving the accuracy and efficiency of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of an air tightness detection device for a valve positioner pilot valve according to the first embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the positioning structure in the first embodiment of the utility model;

[0024] Figure 3 This is a schematic diagram of the auxiliary device in the first embodiment of the utility model;

[0025] Figure 4 This is a schematic diagram of the detection process in the first embodiment of the utility model;

[0026] The markings of the components in the accompanying drawings are as follows: 1. test bench, 2. first liquid storage tank, 3. second liquid storage tank, 4. positioning frame, 5. positioning cylinder, 6. auxiliary device, 7. pilot valve, 11. lifting mechanism, 12. back plate, 31. air intake pipe, 32. conduit, 33. pressure transmission pipe, 41. baffle, 51. push block, 61. auxiliary lifting mechanism, 62. auxiliary motor, 63. batch head, 71. connector. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "front", "back", "horizontal", "vertical", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention. They cannot indicate or imply that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0029] See also Figures 1 to 4The first embodiment of the utility model provides an air tightness detection device for a valve positioner pilot valve 7, comprising: a test bench 1 and a first liquid storage tank 2, a second liquid storage tank 3, a positioning frame 4 and a positioning cylinder 5 which are sequentially arranged on the test bench 1;

[0030] The first liquid storage tank 2 is arranged on the test bench 1 through a lifting mechanism 11, and its initial height is consistent with that of the second liquid storage tank 3, and the liquid levels on both sides are consistent. During the test, the first liquid storage tank 2 is raised to make the liquid level at a high position, and pressure is applied to the air in the second liquid storage tank 3, and its top is sealed;

[0031] The second liquid storage tank 3 is fixed on the test bench 1 through the back plate 12, the top is connected to the pressurizing device through the air inlet pipe 31, the bottom is connected to the first liquid storage tank 2 through the conduit 32, and the side is connected to the joint 71 of the test cavity through the pressure transmission pipe 33. In the initial state, the air pressure on both sides is consistent. During the test, the pressure of the test cavity is created by raising the first liquid storage tank 2 or inputting gas into the second liquid storage tank 3;

[0032] The positioning frame 4 has an arc-shaped groove, which is convenient for stably placing pilot valves 7 of different sizes. The left side has a baffle 41 to limit the position of the pilot valve 7. The driving end of the positioning cylinder 5 has a push block 51 pointing to the direction of the baffle 41 to push the pilot valve 7 placed on the positioning frame 4 to the baffle 41 for fixing.

[0033] The positioning cylinder 5 is arranged on the test bench 1 through a mounting seat, and its driving end is rotatably connected to the side plate of the mounting seat;

[0034] An auxiliary device 6 for screwing the joint into the test cavity interface is arranged on one side of the positioning frame 4. The auxiliary device 6 includes an auxiliary motor 62. The auxiliary motor 62 is arranged on the test bench 1 through an auxiliary lifting mechanism 61, and is initially located at the highest position. A detachable screwdriver bit 63 is arranged at its driving end, pointing to the joint 71 directly below. A sensor is also arranged on its side to measure the distance between the screwdriver bit 63 and the housing of the pilot valve 7 below. When the sensor senses the pilot valve 7, the auxiliary motor 62 moves downward, drives the screwdriver bit 63, and screws the joint into the interface. After the installation of the joint is completed, the auxiliary electrode is retracted, and the other end of the pressure transmission tube 33 is manually connected to the joint to perform air tightness detection;

[0035] The airtightness test is divided into two steps. The first step is to raise the first liquid storage tank 2, use the liquid pressure to pressurize the test cavity, and observe the changes in the liquid level of the second liquid storage tank 3. In the second step, the pressurizing device outputs gas, uses the gas pressure to pressurize the test cavity again, and observes the changes in the liquid level of the second liquid storage tank 3. When the pressure in the test cavity increases and the liquid level of the second liquid storage tank 3 stabilizes, the airtightness of the pilot valve 7 is normal. When the liquid level of the second liquid storage tank 3 continues to rise after the pressure increases, the pilot valve 7 is leaking.

[0036] Specifically, a guide groove is also provided on the arc groove to facilitate the placement of the connector on the other side of the pilot valve 7, and also to ensure that when the pilot valve 7 is against the baffle 41, the connector 71 of the test cavity is located directly above and opposite to the batch head 63.

[0037] Specifically, the push block 51 is a U-shaped structure with an opening to the left, which can not only abut against the housing of the pilot valve 7, but also limit the transmission rod of the pilot valve 7 to ensure the stability of the test cavity.

[0038] In order to better judge the change of the liquid level, a ruler is designed on the second liquid storage tank 3 so that the liquid level data can be seen intuitively.

[0039] In other embodiments of the utility model, a liquid level sensor may be further provided in the second liquid storage tank, and the liquid level change may be recorded by reading the sensor value, thereby determining whether the pilot valve is leaking under the current pressure.

[0040] The beneficial effects of the air tightness detection device of the valve positioner pilot valve of the utility model are:

[0041] 1. Design positioning frame and positioning cylinder to position and fix the pilot valve, which can ensure the stability of the pilot valve position and the test cavity without manual adjustment;

[0042] 2. An auxiliary device is set on one side of the positioning frame to screw the corresponding joint into the test chamber interface. There is no need to manually install the test interface. The interface installation consistency is high and the sealing condition is better. After that, you only need to connect the other end of the pressure transmission tube to the joint to carry out the test, which is conducive to improving the accuracy and efficiency of the test.

[0043] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An air tightness detection device for a valve positioner pilot valve, characterized in that: include: A test bench and a first liquid storage tank, a second liquid storage tank, a positioning frame and a positioning cylinder sequentially arranged on the test bench; The first liquid storage tank is arranged on the test bench through a lifting mechanism; The second liquid storage tank is fixed on the test bench through a back plate, the top is connected to the pressurizing device through an air inlet pipe, the bottom is connected to the first liquid storage tank through a conduit, and the side is connected to the joint of the test cavity through a pressure transmission pipe; The positioning frame has a baffle, and the driving end of the positioning cylinder has a push block pointing in the direction of the baffle; An auxiliary device for screwing the joint into the test cavity interface is arranged on one side of the positioning frame.

2. The air tightness detection device for the pilot valve of a valve positioner according to claim 1, characterized in that: The positioning frame has an arc-shaped groove.

3. The air tightness detection device for the pilot valve of a valve positioner according to claim 2, characterized in that: The arc groove is also provided with a guide groove.

4. The air tightness detection device for the pilot valve of a valve positioner according to claim 3, characterized in that: The push block is a U-shaped structure with an opening facing left.

5. An air tightness detection device for a valve positioner pilot valve according to any one of claims 1 to 4, characterized in that: The auxiliary device comprises an auxiliary motor, which is arranged on the test bench through an auxiliary lifting mechanism, and a detachable screwdriver bit is arranged at the driving end of the auxiliary motor, pointing to the joint directly below.

6. The air tightness detection device for the pilot valve of a valve positioner according to claim 5, characterized in that: A sensor is also provided on one side of the auxiliary motor.

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