JP2007071617A - Deformation detector and asperity detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an asperity detector and asperity detection method for detecting asperities on the surface of an object. <P>SOLUTION: A deformation detector includes a pressure receiving sheet SR which has a fluid F therewithin and becomes deformed by receiving pressure, a pressure keeping sheet SK for keeping the inside pressure, and a deformation detection means D for detecting relative movement with respect to the fluid F occurring when the pressure acting upon the pressure receiving sheet changes. The asperity detection method for detecting the asperities on the object allows the asperity detector and the object to relatively move with the asperity detector while being abutted with the surface of the object. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deformation detector capable of detecting deformation and a method for detecting unevenness of an object such as unevenness using the deformation detector.

In the actual manufacturing process, for example, inspecting the surface distortion of a steel sheet in the automobile manufacturing process, surface irregularities are detected by an engineer tracing the surface of the steel sheet. However, there are differences in the ability of engineers depending on the level of skill, and it takes a long time to acquire skills. In order to quantitatively detect irregularities on the surface of an object, a method using a laser displacement meter or a dial gauge sensor may be considered. However, these methods are not suitable for inspecting a wide area in a short time, and there is also a problem that it takes time to install and set up the equipment.
Therefore, there is a need for a method that allows anyone to easily detect surface irregularities.

  In view of the above circumstances, an object of the present invention is to provide an unevenness detection method for detecting unevenness on an object surface by a simple operation.

The deformation detector of the present invention has a container in which a liquid is enclosed, the bottom surface of the container is a flexible sheet that deforms under pressure, and the upper surface of the container is a flexible sheet that deforms under pressure. And a flow detection means for detecting a relative movement with the fluid generated when the sheet on the bottom surface or the top surface of the container is deformed is installed inside the container. .
In the deformation detector of the present invention, it is desirable that the portion that deforms under the pressure on the bottom and top surfaces of the container is an elastic body such as a rubber sheet. The pressure inside the container is preferably kept higher than the pressure outside the container. The flow detection means is preferably a plate-like elastic body having a strain detection element such as a strain gauge or a PVDF sensor.
The flexible sheet on the bottom surface has a larger area than the flexible sheet on the top surface, the flow detection means has a plate-like body that is bent by the movement of the fluid, and the pre-distortion detecting element is the plate-like body. It is preferable that it is attached. At this time, the plate-like body is preferably an elastic body such as rubber.
The unevenness detection method of the present invention is an unevenness detection method for detecting unevenness of an object, wherein the deformation detector and the object are moved relative to each other while the deformation detector is in contact with the surface of the object. To do.

In the deformation detector of the present invention, the flow detection means is located inside the container and detects the relative movement with the fluid generated when the pressure receiving surface is deformed. It is not transmitted directly to the flow detection means. As a result, even if the pressure-receiving surface is greatly deformed, the deformation detecting means is unlikely to be greatly deformed, so that it is not easily damaged. In addition, since it is difficult for large deformation to occur in the flow detection means, even if a strain detection element is attached to the flow detection means, damage to the strain detection element can be prevented.
In the unevenness detection method of the present invention, the deformation detector of the present invention is slid in a state where the deformation detector is in contact with the surface of the object, and the deformation detector and the object are moved relative to each other, so that the position of the unevenness on the surface of the object is detected. The pressure sensing surface of the deformation detector can be deformed. The deformation of the pressure-receiving surface is detected by the flow detection means in the deformation detector, and irregularities can be detected.
If the internal pressure of the deformation detector is kept high, the flexible sheet on the bottom will follow the concave part of the object surface well, so that not only the convex part but also the concave part can be detected. The flexible sheet on the top has the effect of keeping the pressure in the container almost constant when the flexible sheet on the bottom is deformed.

The following describes the best mode for carrying out the deformation detector of the present invention and the unevenness detection method using the deformation detector.
The deformation detector of the present invention has a container in which a liquid is enclosed, the bottom surface of the container is a flexible sheet that deforms under pressure, and the upper surface of the container is a flexible sheet that deforms under pressure. And a flow detection means for detecting a relative movement with the fluid generated when the sheet on the bottom surface or the top surface of the container is deformed is installed inside the container. .
The pressure receiving surface is not particularly limited as long as it is a material that can be deformed by receiving pressure. The pressure holding surface must be made of a material that can be pressurized by the tension of the surface in order to keep the pressure of the fluid inside the container higher than the outside of the container.
The flow detection means is a plate-like body formed inside the container, preferably in the form of a cantilever or a cantilever. For example, when the pressure applied to the pressure receiving surface increases, fluid flows from the pressure receiving surface side to the pressure holding surface side. In addition, when the pressure applied to the pressure receiving surface decreases, fluid flows from the pressure holding surface side to the pressure receiving surface side. When fluid flow occurs, the plate-like body will bend.
The flow detection means is a plate-like body formed inside the container, preferably in the form of a cantilever or a cantilever. For example, when the pressure applied to the pressure receiving surface increases, fluid flows from the pressure receiving surface side to the pressure holding surface side. In addition, when the pressure applied to the pressure receiving surface decreases, fluid flows from the pressure holding surface side to the pressure receiving surface side. When fluid flow occurs, the plate-like body will bend. By measuring this deflection with a strain gauge, it is possible to detect changes in pressure on the pressure-receiving surface or deformation of the pressure-receiving surface.
The unevenness detection method of the present invention is an unevenness detection method for detecting unevenness of an object, wherein the deformation detector and the object are moved relative to each other while the deformation detector is in contact with the surface of the object. To do.

In the following, the deformation detector of the embodiment will be described with reference to FIG.
The deformation detector S of the present embodiment has an outer shell having silicon oil F (kinematic viscosity: 10000 cSt) inside, and fluid movement detecting means installed in a doubly supported beam shape inside the capsule. Two strain gauges are attached to the fluid movement detection means, and each resistance value is measured and recorded by a strain gauge amplifier and an electronic computer (not shown) connected to them.
The container V has a cylindrical shape with a diameter of 60 mm and a height of 35 mm, and is made of a photo-curing resin. A rubber pressure-receiving sheet SR having a thickness of 0.5 mm and a diameter of 50 mm is installed on the bottom surface, and a rubber pressure-holding sheet having a thickness of 0.5 mm and a diameter of 15 mm is installed on the top surface. As shown in Fig. 1, the shape without the container is a funnel shape, and the fluid movement detection means is installed where the cross-sectional area of the inner shape is small. The fluid movement detection means is a rubber-supported beam with a thickness of 0.5 mm, and two strain gauges G1 and G2 are attached.
When detecting irregularities, the pressure sensing sheet SR of the deformation detector is brought into contact with the object and slid. The time variation of strain generated in the strain gauge at this time is shown in Figs.
Fig. 2 is a graph showing the change over time of the strain generated in the strain gauge when the embodiment is moved back and forth on a smooth surface with convex portions. The change of the distortion value appears by the convex part, and the convex part is detected correctly.
Fig. 3 is a graph showing the change over time of the strain generated in the strain gauge when the embodiment is moved back and forth on a smooth surface with a recess. The distortion value changes due to the concave part, and the convex part is detected correctly.
Fig. 4 is a graph showing the change over time of the strain generated in the strain gauge when the embodiment was moved back and forth on a smooth surface without unevenness. Unlike Fig. 2 and Fig. 3, no signal is detected. That is, it is shown that the time change of the strain shown in FIG. 2 and FIG. 3 is caused by the presence of the convex part and the concave part.

Schematic diagram of an embodiment of a deformation detector It is a graph which shows the time change of the strain which a strain gauge produced when an example was made to contact on the smooth surface with a convex part, and was reciprocated. It is a graph which shows the time change of the strain which a strain gauge produced when an example was made to contact on the smooth surface with a concave part, and was reciprocated. It is a graph which shows the time change of the strain which a strain gauge produced when an example was made to contact on a smooth surface and reciprocated.

Claims (10)

  The container has a liquid sealed therein, the bottom surface of the container is a flexible sheet that deforms under pressure, and the top surface of the container is a flexible sheet that deforms under pressure, A deformation detector, wherein flow detection means for detecting relative movement with the fluid generated when the sheet on the bottom surface or the upper surface of the container is deformed is installed.   2. The deformation detector according to claim 1, wherein the pressure inside the container is maintained higher than the pressure outside the container.   The deformation detector according to claim 1, wherein the flow detection means includes a strain detection element.   The deformation detector according to claim 3, wherein the strain detection element is a strain gauge or a PVDF sensor.   5. The deformation detection according to claim 1, wherein the flow detection means has a plate-like body that is bent by the movement of the fluid, and is installed in a doubly supported beam shape inside the fluid container. vessel.   The deformation detection according to any one of claims 1 to 5, wherein the flow detection means has a plate-like body that is bent by the movement of the fluid, and is installed in a cantilever shape inside the fluid container. vessel.   The deformation detector according to any one of claims 1 to 6, wherein the flexible sheet on the bottom surface of the container has a larger area than the flexible sheet on the top surface of the container.   The deformation detector according to any one of claims 1 to 7, wherein the container has a funnel-like inner shape, and the flow detection means is installed in a portion having a small internal cross-sectional area.   The deformation detector according to claim 1, wherein the fluid is silicon oil.   An unevenness detecting method for detecting unevenness of an object, comprising a container in which a liquid is enclosed, a bottom surface of the container being a flexible sheet that is deformed by pressure, and an upper surface of the container receiving pressure The flexible sheet is deformed, and a flow detection means for detecting a relative movement with the fluid generated when the sheet on the bottom or top surface of the container is deformed is installed inside the container. An unevenness characterized by using a deformation detector and relatively moving the deformation detector and the object in a state where the flexible sheet on the bottom surface of the deformation detector is in contact with the surface of the object. Detection method.