Method of inspecting a body having fine-gap grooves and method of repairing the body
A molding die has through holes composed of feed holes and slit grooves for producing honeycomb structure bodies. The slit groove is formed in at least a part of each through hole. In a method of inspecting the molding die, a light is irradiated into the feed holes side to pass through the through holes. A camera is disposed at the slit groove formation side of the molding die to photograph the amount of light output from the slit groove side. A difference in intensity of the amount of light output from the slit grooves is calculated in order to detect at least the presence of a defective slit groove having an abnormal part. In another method of repairing the defective slit groove, a modifier made of abrasive grains and clay mother material is forcedly provided into the defective slit groove in order to repair or remove the abnormal part.
1. A method of inspecting a molding die for producing a honeycomb structure body of a predetermined shape, the molding die having a plurality of through holes formed in parallel to each other, each through hole being comprised of a feed hole and a slit groove having a flow through passage smaller than a flow through passage of said feed hole, wherein a molding material is fed through the feed holes to extrude the molding material through the slit grooves during the production of the honeycomb structure body,
the method comprising steps of:
irradiating parallel light from a feed hole side of the molding die toward a slit groove side of each of the through holes so that the parallel light passes in parallel through all of the through holes;
measuring, at the slit groove side of the molding die, an amount of the light passed through at least some of the through holes;
detecting the presence of an abnormal part in at least one slit groove of the plurality of through holes irradiated based on a difference in the amount of light measured for the respective through holes.
2. The method of inspecting a molding die according to claim 1 , wherein each slit groove in the molding die has a width of not more than 85 μm.
3. The method of inspecting a molding die according to claim 1 , wherein the quantity of the parallel light passed through the through holes is measured using a camera.
4. The method of inspecting a molding die according to claim 3 , wherein the presence of a defective slit groove in the through hole is detected based on a difference of the amount of the parallel light detected by the camera, and wherein image data corresponding to the defective slit groove in the through hole is displayed.
5. The method according to claim 1 , wherein the parallel light is emitted by a fluorescent lamp.