JPH06126602A - Grinding method for single diameter elongated circular tube by centerless grinder - Google Patents

Abstract

PURPOSE:To improve the grinding quality and the set-up efficiency and to reduce the cost in the case of grinding a single diameter elongated circular tube made of a material hard to be ground with ultra high accuracy by means of a centerless grinder. CONSTITUTION:In the case of performing peripheral grinding for a single diameter elongated circular tube as a material to be ground by a centerless grinder adapted to perform peripheral grinding, with a material to be ground on a work support blab sandwiched between a grinding wheel for grinding and an adjust wheel, the feed angle of the adjust wheel is set to zero or a very small feed angle near zero and the axial movement of the single diameter elongated circular tube supplied on the work support blade is stopped to be stop-ground. After that, the single diameter elongated tube is taken out from the expanded relative space between the grinding wheel for grinding and the adjust wheel according to a grinding method for a single diameter elongated circular tube by a centerless grinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to grind a slender circular tube body with a centerless grinder, which grinds a single-diameter slender circular tube body such as a stainless steel tube, which is difficult to grind, with a very high precision. It is about the method.

[0002]

2. Description of the Related Art A hard-to-grind material such as SUS304 / 303 is used, and "outer diameter: 16 to 32 grits, wall thickness: 1.0 to 0.5 grits.
Slenderness ratio: Approximately 20 "single thin diameter (no step around outer circumference) slender thin-walled tubular body after grinding, with thickness of 0.4 to 0.6, roundness: 0.02 or less・ Straightness: 0.02 or less ・ Cylindricity (diameter difference over the entire circumference): 0.03 or less, etc. When performing thin ultra-high precision grinding, a well-known centerless grinder is used for adjustment. The feed angle of 15 degrees etc. is set on the car, and the thrust in the axial direction is applied to the circular pipe body of the material to be ground.
The through feed grinding method of passing between the grinding wheel and the adjusting wheel is performed, and when performing the ultra-high precision grinding of the above-mentioned degree of difficult-to-grind material, the through feed grinding is performed about 8 to 10 times. Grinding methods are being repeated to satisfy the required accuracy.

[0003]

In the case of performing ultra-high precision grinding of a slender circular tube body made of a difficult-to-grind material by the above conventional feed-through grinding method, feed-through grinding by the same grinder is used.
If you do not repeat it at least several times, the ultra-high precision cannot be satisfied, so the grinding time and the number of man-hours will be large and the grinding productivity will be extremely low. Since it slides on the support blade between the wheel and the adjustment wheel to move in the axial direction, there are problems in quality and cost that the rubbing marks remain on the ground surface.

Further, the setup work of the grinder by changing the size of the material to be ground is performed by adjusting the feed angle of the adjusting vehicle, adjusting the material guides provided at the entrance and the exit of the adjusting vehicle, and adjusting the adjusting vehicle. Since work such as a claw type dresser is required and this setup adjustment has trial and error qualitative,
It is necessary to perform trial grinding about several times to confirm the quality of those setting adjustments. Therefore, it takes a lot of setup time and setup man-hours, and in addition, there is a drawback that requires considerable skill.

The present invention provides a grinding method that solves the above-mentioned problems in the conventional grinding method.

[0006]

The method for grinding a single-diameter slender tubular body by a centerless grinding machine of the present invention which solves the above technical problems is described in "A single-diameter slender tubular body manufactured by a centerless grinding machine. Peripheral grinding is based on the idea of breaking through the above-mentioned established concept that "it must be done by through feed grinding", and stop grinding described below is the gist. That is, "in the outer peripheral grinding of a single-diameter slender tubular body of the material to be ground, by a centerless grinder that grinds the material to be ground on the supporting blade with a grinding wheel for grinding and an adjusting wheel to perform outer peripheral grinding, The feed angle of the adjusting wheel is set to zero degree or a minute feed angle in the vicinity of zero degree, and the movement of the single-diameter slender tubular body supplied onto the supporting blade in the axial direction is stopped to perform grinding. , A method for grinding a single-diameter slender tubular body by a centerless grinding machine, characterized in that the single-diameter slender tubular body is taken out from between the grinding wheel and the adjusting wheel for which the relative distance is increased. It is a feature.

More specifically, in the grinding method of the present invention described above, the feed angle of the adjusting wheel is basically set to zero degree, and the thrust in the axial direction during grinding of the single diameter elongated circular tube body on the supporting blade is set. Stopping grinding is performed with zero, and the single-diameter slender circular tube body on the support blade is used for grinding with both ends in the axial direction abutting lightly on the stopper to keep the axial position constant. By bringing the grinding wheel into contact with the outer circumference, the entire length of the outer circumference is simultaneously ground. But,
With the intention of stabilizing the stopped posture by preventing minute movement in the axial direction due to grinding resistance, the adjustment vehicle is provided with a minute feed angle (about 5 minutes) near zero degree, and an axis that does not cause hit marks by the stopper. May give a small directional thrust. Note that the single-diameter slender tubular body is supplied to and taken out from the supporting blade by automatic feeding and taking-out by a robot hand or the like in a state where the relative distance between the grinding wheel for grinding and the adjusting wheel is widened.

[0008]

According to the above-described grinding method of the present invention, the stop grinding is performed by stopping the movement of the single-diameter slender tubular body on the supporting blade in the axial direction. It is possible to grind the outer circumference of a single-diameter slender circular tube with ultra-high precision and high quality. And the setup work for the grinding process is
Since the feed angle of the adjusting wheel is fixed to zero degree or a minute angle near zero degree, it is not necessary to adjust and set each time the size of the material to be ground is changed. The material guide is also unnecessary, there is no need for guide adjustment setup, and the dresser of the adjusting vehicle is also simple.
Therefore, the setup work is remarkably simplified as compared with the conventional through feed grinding method, and the special skill is also unnecessary.

[0009]

The operation and effect of one embodiment of the present invention and the conventional "through feed grinding method" will be described in detail below. The grinding specifications of the single-diameter slender circular tubular body of the material to be ground used in this example are as follows: "pipe length: 400 grits, pipe diameter: 20 grits, wall thickness: 0.8 grits" Material
"Diameter: 19.2 grits, wall thickness: 0.4 grits" Grinding, "roundness: within 0.02 grits, straightness: within 0.02 grits, cylindricity: within 0.03 grits" Grinding to ultra-high precision product standards, "610 grain diameter and grain: GC, grain size: 8
Under the same grinding conditions of a grinding wheel of 0, bond degree: K, structure: 7, binder: V81S, and a peripheral speed of 2,000 US per minute, the conventional "through feed grinding" and the present invention " The results of comparing "stop grinding" are as follows.

First, in the conventional feed-through grinding method, it takes 8 hours from the start of setup to the completion of setup (including three trial grindings), and the feed angle of the adjusting wheel is set to 15 degrees. Through-feed grinding, which requires a grinding time of 30 seconds, was repeated 10 times to finish the grinding. The grinding quality was a high defect rate of 10% that was out of the product standard.

On the other hand, according to the stop grinding method of the present invention, only 5 minutes are required from the start of setup to the completion of setup (feeding angle of the adjusting wheel is zero degree), and the stop grinding is performed only once for a grinding time of 30 seconds. Finished The grinding quality showed a high quality with a defect rate of only 0.1% out of the product standard. As described above, the present invention is clearly superior to the conventional grinding methods in terms of the number of grinding steps, setup, grinding cost, and grinding quality.

[0012]

As described above, according to the grinding method of the present invention, when a single-diameter slender circular tubular body of a difficult-to-grind material is ground with ultra-high accuracy by a centerless grinder, a particularly excellent grinding quality is obtained. Not only does it have a setup property, but it also has a remarkable effect of reducing the cost.

Claims (1)

[Claims] 1. A centerless grinder that grinds a material to be ground on a supporting blade with a grinding wheel for grinding and an adjusting wheel to grind the outer circumference of a single-diameter slender tubular body of the material to be ground. In, the feed angle of the adjusting wheel is zero degrees, or a minute feed angle in the vicinity of zero degrees is made, grinding is performed by stopping the axial movement of the single-diameter slender tubular body supplied onto the supporting blade, Then, the method for grinding a single-diameter slender circular tube by a centerless grinding machine, characterized in that the single-diameter slender circular tube is taken out from between the grinding wheel and the adjusting wheel for which the relative distance is widened. .