Kabushiki Kaisha Sg

Honda Motor Co., Ltd.

Seiji Hirohashi

Yuji Matsuki

Wataru Ichikawa

Yasuyuki Mizutani

Yuji Taya

Shingi Hoshino

Masaru Ohara

Toshiharu Nakagima

A braking apparatus performs its braking action by pressing a brake bush radially inwardly against a rod. The brake bush is pressed via a plurality of coned disk springs, each of which has a plurality of outer and inner radial recesses extending from its outer and inner peripheral edges, respectively. The outer and inner recesses are arranged in an alternating fashion along the circumference of the spring. As a brake piston moves in the axial direction of the rod, the inner peripheral edge of each of the springs is compressed or deformed radially inwardly. The brake piston is moved by compressed air supplied from outside. By increasing the radial length of each of the inner radial recesses of the coned disk springs in such a manner that the radial outward end of the recess is located far beyond the radial inward end of each adjacent outer radial recess, it is permitted to provide at least three or more coned disk springs around the brake bush. Thus, abrasion of each coned disk spring can be minimized, and durability of the braking apparatus can be greatly enhanced. Further, by forming each of the coned disk springs so as to have a rectangular sectional shape, it is possible for the braking apparatus to perform a sufficient braking function even when the outer and inner peripheral edges of the coned disk springs have been abraded to a considerable degree.

Braking apparatus operated via resilient deformation of coned disk

A spot welding machine includes tip electrodes mounted on the tips of the first and second arms, respectively, a pressing actuator for moving at least one of the first and second arms to apply a pressing force to the tip electrodes, an interelectrode distance detector for detecting a distance between the tip electrodes, and a brake for braking the actuator. The distance between the tip electrodes, i.e., interelectrode distance can be set at any desired intermediate distance between the maximum and minimum distances, by braking the actuator when the arms are opened to a desired degree. In this manner, it is made possible to effectively reduce the required operation time, and by suitably performing such a brake control, it is also made possible to effectively lessen an impact caused when the tip electrodes come into contact with plates to be welded. A speed control device may be provided which variably controls the moving speed of the actuator in accordance with the interelectrode distance. In such a case, it is permitted to properly control the moving speed of the arms and hence of the tip electrodes in response to the current position of the arms, and therefore the contact impact can be effectively lessened.

Spot welding machine

A decrease amount in plate thickness at a spot weld is detected at a predetermined time period when application of pressure is still maintained after termination of power supply to electrodes for spot welding. The decrease amount is correlated with the magnitude of diameter of nugget formed by spot welding, e.g., a larger diameter of nugget signifies a stronger the joint, and therefore, the quality of joint at the spot weld can be examined on the basis of the detected decrease amount. Since a value obtained by integrating plate thickness detection data of the spot weld during the predetermined time period is correlated, as the decrease amount is, with the magnitude of the diameter of a nugget, the quality of the joint may also be examined on the basis of this integrated value. There is provided, in a spot welding machine, a detector for detecting a stroke position of a cylinder for pressing electrodes or a detector for detecting a position of displacement of a tip portion of an arm interlocked with the movement of the electrodes and the distance between the electrodes, i.e., plate thickness, can be indirectly detected by the detector without adversely affecting efficiency of the spot welding work.

Method for checking a spot welded portion and spot welding machine

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Tokyo, Japan

Seiji Hirohashi