Valve seat inspection method and valve seat inspection device using an image recognition camera

Abstract

To provide a valve seat inspection method and a valve seat inspection device using an image recognition camera which can automatically continuously execute a valve seat inspection of a valve with a simple configuration, highly accurately and easily detect a very small leakage amount from a valve seat with the image recognition camera even if the high valve seat leakage performance is requested, and exhibit inspection accuracy equivalent to a case of visually performing the valve seat inspection on a valve in a submerged state by means of visual inspection.SOLUTION: An inspection device body 1 which includes a checking circuit 10 that checks leakage of a reference leakage amount, an inspection circuit 11 in a state where a test valve 20 is installed and an image recognition camera 12 that images bubbles appearing from a tip 21a by inserting an inspection tube 21 to water in a container 22 performs: a checking step of determining whether or not the bubbles appear from the tip 21a of the inspection tube within a checking time with the image recognition camera by switching a circuit switching unit 23; and an inspection step of determining whether or not the bubbles appear from the tip of the inspection tube within the inspection time with the image recognition camera by switching the circuit switching unit.SELECTED DRAWING: Figure 7

Claims

1. A valve seat inspection method using an image recognition camera, comprising: an inspection circuit that communicates with an air supply source and a test valve or a dummy valve to check for a standard leak amount; an inspection circuit that installs a test valve in a closed state with pressure sealed inside a cavity and detects leakage from the test valve; and an inspection device body that is in common communication with the inspection circuit and the inspection circuit and detects leakage by inserting an inspection tube into water in a container and photographing bubbles that appear from the tip of the inspection tube, wherein the inspection device body undergoes an inspection step of switching a circuit switching unit that switches between the inspection circuit and the inspection circuit to determine whether or not bubbles based on leakage corresponding to a standard leak amount appear from the tip of the inspection tube within an inspection time using the image recognition camera; and an inspection step of switching the circuit switching unit to determine whether or not bubbles based on leakage from the test valve appear from the tip of the inspection tube within an inspection time using the image recognition camera.

2. A valve seat inspection method using an image recognition camera according to claim 1, wherein, as a preliminary step to the inspection step and the test step, at least one or all of the following are performed: water level determination by image processing, water level determination by a weight sensor, major leak detection by a flow sensor, and determination of the insertion depth of the test tube by image processing.

3. A valve seat inspection method using an image recognition camera according to claim 1 or 2, wherein low-pressure air is blown into the inspection tube to expel water adhering to the tip of the inspection tube.

4. A valve seat inspection method using an image recognition camera according to any one of claims 1 to 3, wherein the steps of inserting the tip of the inspection tube into water and releasing it to the atmosphere are operated by an operating mechanism.

5. A valve seat inspection method using an image recognition camera according to any one of claims 1 to 4, wherein the inspection device body and its inner wall are coated with an anti-reflective paint to prevent light reflection in order to obtain the detection performance of the image recognition camera.

6. A valve seat inspection device using an image recognition camera, comprising: an inspection circuit that communicates with an air supply source and a test valve or a dummy valve to check for a reference leak amount; an inspection circuit that installs a test valve in a closed state with pressure sealed inside a cavity and detects leakage from the test valve; an image recognition camera that photographs bubbles emanating from the tip of an inspection tube that is in common communication with the inspection circuit and the inspection circuit and detects leakage when the inspection tube is inserted into a container filled with water; a circuit switching unit that switches between the inspection circuit and the inspection circuit; and an operating mechanism unit for inserting the inspection tube into water and opening it to the atmosphere.

7. Valve seat inspection device using an image recognition camera according to claim 6, wherein the image recognition camera performs at least the following functions: determining whether there is a leak based on the presence or absence of bubbles emanating from the tip of the inspection tube, determining the water level in the container, and determining the insertion depth of the inspection tube.

8. The valve seat inspection device using an image recognition camera according to claim 6 or 7, wherein the operating mechanism is a linear servo mechanism that moves up and down.

9. A valve seat inspection device using an image recognition camera according to any one of claims 6 to 8, wherein the inspection tube is provided with a low-pressure air blowing section to discharge water adhering to the tip of the inspection tube.

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