JPS6067081A - Screw cup grinding wheel - Google Patents

Abstract

PURPOSE:To improve the sharpness by forming the grinding face or the diamond face into specific screw shape thereby easily maintaining the flatness of entire chip and discharging chips efficiently. CONSTITUTION:Diamond layers 2 to be formed on the end face of cup-shape base metal 1 is arranged in screw shape by arranging chips 21 of screw vane shape having chip width increasing in proportion to the diameter from the center of base metal 1 while curving in counter rotary direction with predetermined interval to facilitate maintaining of entire flatness of chip thus to discharge chips by centrifugal force produced through rotation of chip screw and wind pressure and to improve the sharpness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cup-shaped grindstone used for applications such as surface grinding and single chamfering.

-1th, diamond grindstones are roughly divided into two types: straight type (peripheral type) and cup type, the former is usually used for cutting, and the latter for surface grinding, 9-chamfering, etc. The latter cup-shaped grindstone is shown in Figure 1.
A diamond layer 2 formed by sintering diamond abrasive grains on the top surface of the cup-shaped base metal 1 using a binder such as metal bond.
(usually called a diamond layer on 5R) is formed.

When such a cup-shaped grindstone is used for surface grinding, due to the difference in circumferential speed between the inner circumference and the outer circumference of the diamond layer, in other words, in Fig. 1, the grindstone angular velocity is ω, outer radius rl + inner radius r2. As a result, a two-peripheral speed difference 2 (rl-r2)ω occurs, causing severe wear of the outer peripheral diamond layer.

# because the flatness of the entire chip tends to collapse quickly.

This will cause a decrease in stone durability. Therefore, such surface grinding requires a great deal of skill.

In order to solve the functional defects of the cup-shaped grindstone used for surface grinding, etc., the present invention was developed as a result of intensive research, and the diamond layer was designed to reduce the speed of the diamond layer at one periphery by taking into account the difference in circumferential speed between the outer periphery and the inner periphery Hp. Surprisingly, by arranging the chip as a whole in the shape of a screw, in which the chip I gradually increases and extends toward This tool was developed after discovering that force and wind pressure can efficiently discharge chips and improve and maintain sharpness.

The present invention will be specifically described below based on one application example.

FIG. 2 is a plan view of a cup-shaped grindstone according to the present invention.

The diamond layer 2 formed on the end face of the cup-shaped base metal 1 is
A screw blade-shaped tip 2 whose tip width increases in proportion to the radius from the center of the tip and extends curved in the counter-rotation direction of the grinding wheel.
1 and 21- are arranged at predetermined intervals so as to form a roughly screw shape. Specifically, in the drawing, the screw blade tips are arranged at intervals of 40 degrees in the shape of circular arcs with a constant radius R within 20 degrees drawn between the inner and outer circumferences.

Therefore, the chip l]W is 2πr x 20/36
0, and gradually increases from the inner circumference toward the outer circumference in proportion to the radius r, that is, the peripheral speed 2ωr (ω is the angular velocity).

When surface grinding of concrete was performed using a cup-shaped grindstone having the above shape and a conventional cup-shaped grindstone, the following results were obtained.

Example concrete slab for sidewalk (JrSA 5304-
300 x 300 x 60) was used as an object to be ground, the cup-shaped grindstone shown in FIG. The results were as follows.

Amount of chip wear (indicated by height) Average: 0.28 cm = 0.028 cm Average amount of concrete ground per unit time before test: 1 work, 200 g Average after test: 6,600 g Average amount of grinding: 4,600 g Volume: 2130 c% ( Ratio m 2.25g/cta
C) Durability (concrete grinding amount/chip wear amount) 2130cJ/0. '028cm = 7607
0cJ Comparative Example: Using the same workpiece, a conventional cup-shaped grindstone of the same size but with a diamond layer formed on the entire surface was attached to the disc Sangu, and surface grinding was performed for 1 hour. The amount of grinding of concrete was compared. The results were as follows.

Tip wear amount (indicated by height) Average wear fit 0.16+in = 0.016cm
'Concrete grinding amount per unit time Average before test 11,900g Average after 9,000g Average grinding amount 1,900 g Volume 844CJ Durability (concrete grinding amount/chip wear M) 844c
i / 0.016cm = 52750ci or more, the amount of concrete grinding per unit time is approximately 2.5 times that of the conventional method, and the cutting quality is not improved.
The durability is also approximately 1.44 times greater. Furthermore, when using the two products of the present invention, even an unskilled person did not experience any dripping of the chips, and the chips were scattered far away, making it sanitary.

As is clear from the above description, there are three aspects of the present invention.

By forming the diamond layer, which serves as the grinding surface of the object to be ground, into a certain screw shape, the flatness of the entire chip is easily maintained, increasing durability and increasing the efficiency of grinding concrete, etc., making it extremely economical. It is of great value.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional cup-shaped grindstone, and FIG. 2 is a plan view of a cup-shaped grindstone to which the present invention is applied. ■-Cup-shaped base metal, 2-diamond layer. 21-Diamond chip. Patent applicant Koji Togawa, patent attorney representing Kure Seisakusho Co., Ltd.

Claims (1)

[Claims] ■ The diamond layer 2 formed on the end face of the cup-shaped base metal 1 is
Chips 111 increase in proportion to the radius from the center of the base metal 1 and extend toward the periphery while being curved in the counter-rotation direction of the grinding wheel.The chips 21- are arranged at predetermined intervals so as to form a roughly screw shape. A screw-shaped cup whetstone characterized by: