JPS6331884Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a rotary grinding tool used for deburring and chamfering workpieces.

(Prior art) When using a rotary grinding tool such as an air grinder for deburring or chamfering a workpiece by attaching it to an industrial robot, etc., the grinding wheel is pressed with an appropriate pressure according to the hardness of the workpiece. Difficult to press into workpiece. For this reason, during deburring or chamfering work, if the pressing force of the grindstone against a highly hard workpiece is too large, the frictional resistance will become extremely large, and the grindstone will stop rotating, resulting in cutting defects. If the pressing force of the grinding wheel is too large for a workpiece with low hardness, excessive cutting will occur, and if the pressing force between the workpiece and the grinding wheel is too small, the cutting time will take longer and work efficiency will decrease, etc. There was a problem. Therefore, as seen in Japanese Patent Application Laid-open No. 57-194877, a rotary grinding tool equipped with a grinding wheel rotated by a motor inside a support frame fitted into a cylinder with a pressure spring and pressed downward. A technique has been disclosed that solves the above-mentioned problems by holding the main body in a swingable manner.

(Problem to be solved by the invention) However, in the technique of the above-mentioned publication, although pressure in the vertical direction can be adjusted by adjusting the spring pressure, pressure in the lateral direction can be adjusted by using multiple spherical bearings. However, depending on the target workpiece, the above-mentioned problems cannot be solved.

(Means for Solving the Problems) The present invention was completed with the aim of creating a rotary grinding tool that solved the above-mentioned problems, and includes a hollow piston in a cylinder and a presser foot that forces the hollow piston downward between each other. A rotary grinder is fitted with a spring interposed therebetween, and its lower end is in contact with and supported by a spring pressure adjustment nut screwed onto the lower end of the cylinder, and a hollow piston has a grinding wheel rotated by a motor at its lower end. The tool body is loosely fitted and its upper end is held swingably on the ceiling surface of the hollow piston via a spherical bearing, and the lower part of the rotary grinding tool body is surrounded by the inner wall of the lower part of the hollow piston. It is characterized in that it is held by a compressed air type elastic holding member that is connected to an air pressure adjustment mechanism and can freely adjust the pressure.

(Function) Such a rotary grinding tool is fixed with a cylinder at the end of the arm of an industrial robot.
During use, the amount of compressed air in the elastic holding member and the compression amount of the presser spring are adjusted by operating the spring pressure adjustment nut and the air pressure adjustment mechanism so that the elasticity and spring pressure correspond to the hardness of the workpiece. The lower part of the rotary grinding tool body is elastically held with a predetermined holding force by the bulging elastic holding member, and in this state, the arm is moved at a predetermined speed while the grinding wheel of the rotary grinding tool body is being held. You can deburr and chamfer the work piece using this grinding wheel in the usual manner.

(Embodiments) Next, the present invention will be described in detail with reference to illustrated embodiments.

Reference numeral 1 denotes a cylinder attached to the tip of an arm 2 of an industrial robot, and a hollow piston 3 is fitted inside the cylinder so as to be movable up and down. The hollow piston 3 is pressed downward against the cylinder 1 by a spring 4, and the lower end of the hollow piston 3 comes into contact with a spring pressure adjustment nut 5 screwed onto the lower end of the cylinder 1, so that the spring pressure can be adjusted freely. 3 can only be displaced upwardly against the pressing spring 4. Further, a rotary grinding tool main body 7 is loosely fitted into the hollow piston 3, and its upper end is held by a spherical bearing 6 provided on the ceiling surface of the hollow piston 3, so that the rotary grinding tool main body 7 can be moved in any direction using the upper end as a fulcrum. Furthermore, a membrane-like elastic holding member 9 made of soft rubber or the like is provided on the lower inner wall of the hollow piston 3 to elastically hold the lower outer wall of the rotary grinding tool body 7. An air chamber 10 is formed by the lower part of the hollow piston 3 and the elastic holding member 9, and the air chamber 10 includes a pressure adjustment mechanism 11.
Compressed air is introduced through the The air pressure adjustment mechanism 11 is composed of a pressure reducing valve 12 and a pressure gauge 13, and can set the internal pressure of the air chamber 10 to an arbitrary value. By adjusting the pressure reducing valve 12, the compressed air type elastic Holding member 9
The elastic holding force against the rotary grinding tool main body 7 can be varied by adjusting the elasticity of the tool body 7, and it is attached to the tip of the rotary grinding tool main body 7 and rotated by a built-in air motor or electric motor depending on the hardness of the workpiece. The pressing force between the grinding wheel 14 and the workpiece can be changed.

With this structure, the spring pressure of the pressing spring 4 is adjusted by rotating the spring pressure adjustment nut 5 to correspond to the hardness of the workpiece, and the pressure reducing valve of the air pressure adjustment mechanism 11 is operated to adjust the elasticity. When used by adjusting the amount of compressed air in the holding member 9, the rotary grinding tool main body 7 has an upper end that is swingably held by the hollow piston 3, and an elastic member that is swollen adjustably by the compressed air. Since the holding member 9 holds the lower outer wall of the rotary grinding tool main body 7 with a predetermined holding force, the amount of expansion of the elastic holding member 9 can be changed depending on the hardness of the workpiece. The grinding wheel 14 of the rotary grinding tool main body 7 cuts the burr of the workpiece under the elastic force of the press spring 4 and the elastic holding member 9, which are always adjusted to an appropriate pressing force. The grinding wheel 14 will not stop rotating due to excessive pressure contact force, resulting in poor cutting.Furthermore, even with a workpiece with low hardness, excessive pressure force will not cause overcutting, and the cutting process will be improved. There is also no increase in machining time that would otherwise occur if the pressing force between the grinding wheel 14 and the workpiece is reduced in order to prevent defects or excessive cutting. Note that the elastic holding member 9 provided on the hollow piston is fixed by the upper and lower rings 16 as in the other embodiment shown in FIG. The holding member 9 may be made to bulge.

(Effects of the invention) As is clear from the above description, the present invention is capable of always pressing the grinding wheel of the rotary grinding tool body against the workpiece with an appropriate pressing force, no matter what the target workpiece is. Moreover, the spring pressure and air pressure can be adjusted easily by operating the spring pressure adjustment nut and the air pressure adjustment mechanism, so it has the advantage that it can be easily done from the outside, compared to conventional It has great practical value as it solves the problems of this type of rotary grinding tool.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of main parts showing another embodiment of the present invention. 1: Cylinder, 2: Hollow piston, 4: Pressing spring, 5: Spring pressure adjustment nut, 6: Spherical bearing,
7: Rotary grinding tool body, 9: Compressed air type elastic holding member, 11: Air pressure adjustment mechanism.

Claims (1)

[Scope of utility model registration request] A hollow piston 3 is fitted into a cylinder 1 with a presser spring 4 interposed therebetween that urges the hollow piston 3 downward, and its lower end is abutted against and supported by a spring pressure adjusting nut 5 screwed onto the lower end of the cylinder 1. In addition, a rotary grinding tool main body 7 having a grinding wheel 14 rotated by a motor at the lower end is loosely fitted into the hollow piston 3, and its upper end is rocked to the ceiling surface of the hollow piston 3 via a spherical bearing 6. A compressed air type elastic holding member 9 is movably held, and the lower part of the rotary grinding tool main body 7 is surrounded by the inner wall of the lower part of the hollow piston 3 and is connected to the air pressure adjustment mechanism 11. A rotary grinding tool characterized in that it is held with.