JP2010023161A - Rotation grinding wheel for disc grinder having slit or chain line-like opening hole on cutting surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation grinding wheel for a disc sander of a handy type used for welding and finishing of the cutting surface after a steel material or the like is machined, the rotation grinding wheel having grinding performance more excellent than a conventional one and capable of maintaining the performance to the final stage. <P>SOLUTION: A slit is formed on the rotation grinding wheel. Thereby, removal of a chip becomes sufficient and a clogging phenomenon is eliminated. The heated and efficiently scattered chip suppresses high temperature deterioration of the grinding wheel by heat release effect and reduces an abrasion amount of the grinding wheel. Further, the end part of the slit has function of a blade of a drill, thereby, the grinding wheel for the disc grinder whose sharpness does not fall to the last stage is attained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  After processing steel, etc., use a hand-held disc sander for finishing welding and cutting surfaces and cutting. It is about this rotating whetstone.

Conventionally, grinders called hand-held baby sanders are used for processing steel materials. This rotary whetstone is obtained by dispersing alumina-based abrasive grains in a resin such as phenol and solidifying it at a temperature of about 200 ° C. to form an abrasive grain layer. Glass fiber is put into the abrasive layer to reinforce. Alumina-based abrasive grains have a size of about 0.5 mm.
On the other hand, cutting grindstones used for stones, concrete, tiles, etc. are formed by rotating CBN (cubic boron nitride) abrasive grains or diamond abrasive grains on the outer periphery of a thin steel disk with a bond such as metal or vitrified to form a rotational cutting grindstone (for example, Patent Document 1 and Patent Document 2).
The fundamental difference between a cutting grindstone such as concrete and a disc sander grindstone is the difference between a durable grindstone and a consumable grindstone that decreases with use.
Cutting grindstones such as concrete have a structure in which expensive CBN (cubic boron nitride) or diamond abrasive grains are attached to the outer periphery of a steel disk. The external shape is hardly changed by use.
On the other hand, the disc sander grindstone uses alumina abrasive grains that are significantly cheaper than diamond abrasive grains.

Japanese Patent Laid-Open No. 11-198052 Japanese Patent Laid-Open No. 11-285777

Conventional disc sander whetstones give a satisfactory sharpness at first. However, as it is used, the cutting performance of the abrasive surface gradually deteriorates due to deterioration due to wear of the abrasive grain edge and clogging.
Unlike grindstones that can be used for concrete and other construction, the steel processing disc sander grindstone has a low-cost consumable specification. And because it is not resistant to high temperatures, the abrasive grains and the phenolic resin layer will melt when the frictional heat due to clogging exceeds the limit temperature of 200 ° C, and the grindstone surface will melt, further clogging. The range expands.
The clogging phenomenon makes cutting impossible and at the same time significantly reduces the life of the wheel due to melt wear.
The object is to realize a grindstone that is sharper than the conventional one from the beginning, and that this performance continues to the end.

The problem was solved by the following means in the rotating grindstone for disc grinders.
An effective cutting surface from the outer periphery to the inner circle has one or more slits.
The effective cutting surface from the outer periphery to the center inner circle is provided with one or more chain line-shaped opening holes.
In the above (1), the slit width is in the range of 0.1 to 6.0 mm.
4) In said (2), it has the range of chain line-shaped opening hole 0.1-6.0 (PHI) mm.

When clogging occurs at one place on the surface of the grindstone, the grindstone rotates while in contact with the workpiece, but the cutting cannot be performed, so that no cutting is generated.
The thermal energy generated during cutting causes the facets to become red hot. Then, the high-temperature red hot facets are blown into the atmosphere to prevent heat accumulation on the grindstone. Abnormal heat storage to the grindstone progresses by eliminating this heat dissipation effect due to clogging.
However, the effect of providing the slit will be described with reference to the specific rotating grindstone shown in FIG. 1 and FIG. 3. For example, as shown in FIG. The contact is interrupted for an instant. The facets generated when the cut object and the grindstone are separated for an instant are efficiently scattered in the space. As a result, the facet is less likely to be caught in the subsequent cutting portion, and the effect of making clogging difficult to occur is produced.
In this way, the grindstone is shaved by the work piece while shaving the work piece, so that the grindstone is deprived of the generated heat as the high-temperature cutting pieces are scattered in the space. Sufficient facet scattering results in an efficient heat dissipation effect and prevents the grindstone from rising to 200 degrees, the limit temperature of the grindstone material.

Next, the further effect by providing a radial slit in a grindstone surface is demonstrated.
For example, when working as shown in FIG. 3, an external force 15 in use, which is a force for pressing the grinding wheel through the grinding wheel shaft support 18 and the grinding wheel main body support portion, is applied to the contact surface between the grinding stone and the workpiece. Thereby, when the force before the work is not applied, the point on the grindstone contact point 13 at the time of no load is pressed by the external force 15 at the time of use during the work so that the grindstone is thin, so the grindstone contact after the load is applied. Warps to point 14. This warpage is a displacement amount 16 due to the bending. Since the grindstone rotates in the direction of the long arrow, the contact point with the cut object is continuously rubbed until it reaches the end of the slit 11 immediately before reaching the next slit 1.
When the contact point with the cut object is applied from the slit end portion 11 to the slit end 12 of the drill blade effect, the grindstone surface 19 remains a no-load plane because the external force 15 is not applied yet. Thus, the state does not become the state of the grindstone contact point 14 after loading, and the displacement 16 due to bending does not occur.

As a result, a moment after passing through the gap of the slit 1, the slit end 12 of the grindstone drill blade effect comes into contact with the workpiece. At this time, the slit end 12 of the drill blade effect is in the same state as the cutting edge 17 of the drill of FIG. For this reason, the cutting efficiency improves because the biting into the cut object easily occurs. As a result, the slit edge 12 of the drill blade effect is also strongly worn by the cut material, and the next new continuous point corresponding to the grindstone contact point 14 after loading is also the same. As a result, the new abrasive surface is easily exposed. This is an increase in the state in which new abrasive grains whose corners are not worn down are in contact with the workpiece, which is a factor in improving cutting efficiency.

Next, the effect of providing the chain line-shaped opening hole will be described with reference to a specific rotating grindstone shown in FIG. 6. For example, by having the radial chain line-shaped opening hole 4 on the grinding wheel effective range surface 20 as shown in FIG. 6, Except for the grindstone surface 19 between the two adjacent to each other, the contact between the workpiece and the grindstone is interrupted for an instant. The facets generated when the cut object and the grindstone are separated for an instant are efficiently scattered in the space. As a result, the facet is less likely to be caught in the subsequent cutting portion, and the effect of making clogging difficult to occur is produced.
In this way, the grindstone is shaved by the work piece while shaving the work piece, so that the grindstone is deprived of the generated heat as the high-temperature cutting pieces are scattered in the space. Sufficient facet scattering results in an efficient heat dissipation effect and prevents the grindstone from rising to 200 degrees, the limit temperature of the grindstone material.
Next, the further effect by providing the chain-line-shaped opening hole 4 in the grindstone surface 19 is demonstrated.
For example, when working as shown in FIG. 6, an external force 15 in use, which is a force for pressing through the grindstone shaft hole 18 to the contact surface between the grindstone and the cut object and through the grindstone main body support portion, is applied. Thereby, when the force before the work is not applied, the point on the grindstone contact point 13 at the time of no load is pressed by the external force 15 at the time of use during the work so that the grindstone is thin, so the grindstone contact after the load is applied. Warps to point 14. This warpage is a displacement amount 16 due to the bending. Since the grindstone is rotating in the direction of the long arrow, the grindstone contact point 14 after loading, which is the point of contact with the cut object, is the opening hole end of the drill blade effect immediately before reaching the next chain line-shaped opening hole 4. It rubs continuously until it reaches 4-1 part.

The structure of the grindstone is thin immediately before the contact point between the workpiece and the grindstone reaches the chain-line-shaped opening hole 4, and the interval between the grindstone surfaces 19 adjacent to the opening hole is narrow, so that the semicircle on the traveling direction side is reduced. In this case, a displacement 16 due to bending is generated by the external force 15 during use.
When the contact point between the workpiece and the grindstone hits the opening hole end 4-1 of the drill blade effect, this portion is slightly affected by the external force 15 during use, but is slightly distorted. It works on the cut object in a state close to the contact point 13. As a result, at the same time as cutting the workpiece, the opening hole end 4-1 of the drill blade effect is also strongly worn away from the workpiece. Further, the next new continuous point corresponding to the grindstone contact point 14 after loading is also worn out in the same manner, and the new grinding surface is easily exposed. This is an increase in the state in which new abrasive grains whose corners are not worn down are in contact with the workpiece, which is a factor in improving cutting efficiency.

Further, the grindstone having the slits and the chain line-shaped opening holes can see the cut object from the top by the afterimage effect even when the grindstone is rotating during the work.
Conventionally, the work has to be interrupted each time in order to check the machining status during the work. However, because this effect allows the workpiece to be viewed continuously, the operator can grasp the situation gradually while proceeding with the machining, and can determine the approximate dimensions, depth of cut, etc. .
According to the present invention, even in the same work, the work efficiency is improved as compared with the conventional work, and the time can be shortened.

[Example]
An embodiment will be described with reference to FIG. 1 showing an overall view of a rotating grindstone for a disk grinder having four radial slits. The grindstone shaft hole 18 is a center opening hole for fixing the rotary grindstone to the threaded rotation shaft of the disc grinder body with a nut. The rotational force from the shaft is transmitted to the grindstone surface 19 after passing through the grindstone support part having a slightly depressed shape in the shape of a disk to rotate the grindstone main body in the direction of the long arrow. The grindstone effective range surface 20 has four radial slits 1 centered on the grindstone shaft hole 18. Moreover, the center side edge part of the slit 1 has a circular arc. The size of the arc is a semicircle having a diameter of 0.1 to 6.0 mm, which is the slit width. Thus, by providing the slit, the stress applied to this portion during rotation is dispersed without being concentrated, so that the grindstone effective range surface 20 can be used safely without being worn out. In addition, as already described in paragraph 0005, since the red-hot face due to the gap of the slit 1 is efficiently scattered in the atmosphere, abnormal heat accumulation exceeding 200 degrees does not occur on the grindstone surface 19. This makes it possible to prevent premature deterioration of the grindstone material due to heat, thereby producing an effect of extending the life of the grindstone.

Similarly, as described in paragraphs 0006 and 0007, when the external force 15 at the time of use in FIG. Thereby, the slit end 12 of the drill blade effect achieves the same effect as the drill blade 17 of FIG. 2 and easily bites into the workpiece. The grindstone of this case has a function to cut the work piece and to cut the workpiece while scattering the facet. The grindstone surface 19 is continuously cut by the workpiece until the contact portion between the workpiece and the grindstone passes the slit end 12 of the drill blade effect and reaches the grindstone contact point 14 after the next load. That is, during this time, the grindstone surface 19 is in a state where abrasive grains whose new corners have not been worn out appear from below. This effect improved the cutting efficiency.
Next, the width and effect of the slit will be described. The slit width is 0.1 to 6.0 mm, and this is divided into (A) 0.1 to 2.0 mm (B) 2.1 to 4.0 mm (C) 4.1 to 6.0 mm. Compare cutting performance. Although there is no clear difference as a result, (b) and (c) have slightly better cutting performance than (b).
In addition, since there is a slit, the lower workpiece can be seen even during processing due to the afterimage effect, but the section (A) is slightly darker than (B) and (C). However, it does not greatly affect the use at the site where the work environment is different.

FIG. 4 shows an embodiment of a rotating grindstone having a safety strength increasing type and having a radial inner periphery and a slit in two steps on the outer periphery. The basic function is the same as the rotating grindstone for disk grinder having four radial slits in FIG. The difference lies in that the outer peripheral slit 2 and the inner peripheral slit 3 are each arranged in a radial manner in two stages. The rotational force from the disc grinder body shaft is transmitted from the grinding wheel shaft hole 18 to the grinding wheel surface 19 through the grinding wheel support portion with a slight depression, and rotates the grinding wheel body in the direction of the long arrow. In FIG. 1, the length of the slit 1 extends toward the center of the grinding wheel shaft hole 18 toward the inner peripheral limit of the grinding wheel surface 19 to maximize the grinding wheel effective range surface 20 when being transmitted to the grinding wheel surface 19 through the grinding wheel support portion. I am doing so.

As a result, the stress applied to the grindstone during the operation, that is, the external force 15 at the time of use shown in FIG. 3, is applied within a range of 90 degrees on the grindstone inner circumference sandwiched between the two slits. On the other hand, the rotary grindstone having a radial inner circumferential and outer circumferential slit with the increased safety strength shown in FIG. 4 extends only half of the grindstone surface 19 toward the length of the outer circumferential slit. In addition, the inner peripheral slit 3 which is shifted by 45 degrees from the outer peripheral slit 2 has a structure in which the length extends from the inner periphery of the grindstone surface 19 to the outer side only to half of the grindstone surface 19. As a result, the grindstone surface 19 is not separated by the outer peripheral slit 2 and the inner peripheral slit 3. Therefore, the external force 15 at the time of use in FIG. 3 is applied as a load in a range of 90 degrees × 2 = 180 degrees sandwiched between two inner peripheral slits 3 as indicated by two short arrows on the grindstone surface 19 in FIG. It will be a thing. In the case of the disc grinder rotary grindstone having the four radial slits shown in FIG. 1, this is a rotary grindstone with twice the strength increase compared to receiving a load in the range of 90 degrees.

  FIG. 5 shows an embodiment of a rotating grindstone having a safety strength increasing type and having slits in two stages of an inner periphery and an outer periphery. Each of the outer peripheral slit 2 and the inner peripheral slit 3 is not necessarily arranged in a radial pattern around the grindstone shaft hole 18, and the performance is not inferior. The function is the same as that of the rotating grindstone having the safety strength increasing type in FIG. However, the number of slits of each of the outer peripheral slit 2 and the inner peripheral slit 3 needs to have symmetry in order to maintain the grindstone weight balance during rotation.

FIG. 6 shows an example of a rotating grindstone having four rows of chain-line-shaped opening holes in a radial pattern. The basic function is the same as that of the rotating grindstone in FIG. As shown in FIGS. 1 and 3, the grindstone surface 19 is clearly divided by the slit 1 from the next. As a result, there is a possibility that a problem of safety strength in addition to the performance may occur depending on rough usage conditions. In consideration of the increase in safety strength without significantly degrading the performance, the rotating grindstone having four lines of chain-line-shaped opening holes shown in FIG. Since the chain-line-shaped opening holes 4 are not continuously connected like the slits 1, a slight grindstone surface 19 remains between the adjacent opening holes. As a result, the strength is higher than in the case of the slit 1 clearly divided. As for the function, as in the case of the rotating grindstone for a disk grinder having four radial slits in FIG. The amount of displacement 16 due to the bending is generated.

When the chain line-shaped opening hole 4 in FIG. 6 moves in the rotation direction, the open end of the 4-1 drill blade effect in the upper half of the semicircle functions corresponding to the drill blade 17 in FIG. The amount of displacement 16 due to the bending generated at this time is smaller than that of the slit 1, and the amount of biting into the workpiece is also reduced. This is due to the fact that the grindstone has increased safety strength and has a corresponding rigid structure. As a result, the cutting efficiency is lowered, but the size of the chain-line-shaped opening hole 4 is used. When the range of the chain-line-shaped opening hole 0.1 to 6.0 Φ mm is divided into three (i) 0.1 to 2.0 Φ mm (b) 2.1 to 4.0 Φ mm (c) 4.1 to 6.0 Φ mm, The cutting performance is increased in proportion to the size of the opening hole. Depending on the conditions of use, whether the chain-line opening hole 4 is made smaller to increase the rigidity of the grindstone to increase the safety strength, or the rigidity is reduced, but the diameter of the chain-line opening hole 4 is increased to increase cutting performance Can be selected.

FIG. 7 shows an embodiment of a rotating grindstone having a safety strength increasing type and having chain-line-shaped opening holes in two stages of a radial inner circumference and an outer circumference. The basic function is the same as that of the rotating grindstone having four rows of chain-shaped linear aperture holes in a radial pattern in FIG. The reason why the safety strength is increased is the same as that described in FIG. In FIG. 7, a short arrow is shown on the left and right sides of the grindstone surface 19 with the inner circumferential chain line opening hole 6 interposed therebetween. As a result, the stress applied to the grindstone during processing is 90 degrees in the case of the embodiment of FIG. Compared to this, the rotating grindstone having the chain-line-shaped opening holes in two stages of the inner circumference and the outer circumference in the radial direction is increased by the safety strength increase in FIG. Since the load at the time of use is received by the grindstone surface 19 within the range of twice, the safety strength is increased.

In the paragraphs 0013 and 0014, the alternative of increasing the safety strength and the cutting efficiency of the rotating grindstone having four rows of chain-line-shaped opening holes in FIG. 6 is already described. In order to improve the cutting efficiency by the safety strength increasing grindstone shown in FIG. 7, a grindstone is realized in which the safety strength does not decrease even if the diameter of the chain line-shaped opening hole 4 is increased.
FIG. 8 shows an embodiment of a rotating grindstone having increased safety strength and having chain-line-shaped opening holes in two stages, an inner periphery and an outer periphery. The basic function is the same as that of the rotating whetstone shown in FIG. The difference is that the outer peripheral chain line-shaped opening holes 5 and the inner peripheral chain line-shaped opening holes 6 are not arranged radially at equal intervals around the grindstone hole shaft 18, but these opening hole rows are as shown in FIG. Although the angle to the center is arbitrary, they are arranged symmetrically in order to avoid a state in which the weight balance is lost during rotation and abnormal vibration is generated.

FIG. 9 shows an embodiment of a rotating abrasive having a curved chain line-shaped opening hole in which the safety pitch is increased and the front hole row and the rear hole row are displaced from each other. Since the opening holes of each other are in the form of chain lines, they are not in contact with each other, but this results in a structure in which the grindstone surface 19 remains between the opening holes. The shifted curved chain linear opening hole 8 is arranged so as to be shifted to the grindstone shaft hole 18 side by a pitch of one hole from the reference curved linear opening hole 7. The chain-like opening portion that has to be discontinuous with respect to the workpiece due to the grinding wheel surface 19 in between acts as a continuous opening as the grinding wheel rotates. The opening in the next row where the opening of one pitch is shifted following the previous row having no opening works on the workpiece. As a result, the grindstone surface 19 between the two opening holes does not become a blind spot. The combined function of the two lines of the curved curved line opening hole 7 and the curved curved line opening hole 8 of the curved chain opening hole array performs the same function as the slit 1 while having the opening hole with increased safety strength. A rotating grindstone was realized that efficiently scattered the facets and at the same time improved the cutting effect of the drill blade 17.
This grindstone is used both for plane cutting and for cutting. A comparison between a conventional grindstone and a grindstone with slits is as follows, and the effect is remarkable.

The rotation grindstone whole figure for disk grinders which has four radial slits. Drill blade shape Detailed view of slit warpage Rotating whetstone diagram with slits on the inner circumference and outer circumference in a radial pattern with increased safety strength Rotating whetstone diagram with slits on the inner and outer circumferences with increased safety strength Rotary whetstone diagram with four rows of chain-line-shaped apertures in a radial pattern Rotating whetstone diagram with chain-line-shaped opening holes in a radial pattern on the inner circumference and outer circumference in two stages with increased safety strength Rotating whetstone diagram with chain-line-shaped opening holes on the inner circumference and outer circumference in two steps with increased safety strength Rotating whetstone diagram with curved chain line opening holes with increased safety strength and shifted hole pitch between front hole row and rear hole row

Explanation of symbols

1. Slit 11. Slit end
2. Outer peripheral slit 12. The slit edge of the drill blade effect
3. Inner peripheral slit 13. 3. Wheel contact point when there is no load Chain line-shaped opening hole 14 ・ Wheel contact point after loading 4-1 Open hole end of drill blade effect 15 ・ External force during use
5). 15. Peripheral chain linear opening hole Displacement due to deflection
6). Inner peripheral chain linear opening hole 17. Drill blade
7). Reference curved chain linear opening hole 18. Wheel shaft hole
8). Displaced curved linear opening 19. Wheel surface
9. 20. Reference curved chain linear opening hole pitch circle Wheel effective range surface
10. Staggered curved linear opening hole pitch circle

Claims (4)

A rotating grindstone for a disk grinder in which one or two or more slits are provided on the effective cutting surface from the outer periphery to the center inner circle. A rotating grindstone for a disk grinder in which one or two or more chain-line-shaped opening holes are provided on an effective cutting surface from an outer periphery to a center inner circle. The rotary grindstone for a disk grinder having a slit width of 0.1 to 6.0 mm in claim 1. The rotary grindstone for a disk grinder having a chain line-shaped opening hole range of 0.1 to 6.0 Φmm in claim 2.

Images