JPH07328919A - Grinding wheel holding structure - Google Patents

Abstract

PURPOSE:To prevent a grinding wheel from falling by providing a straight shaft section and a taper shaft section on a grinding wheel hold section, forming a straight hole section and a taper hole section corresponding to the straight shaft section and taper shaft section on the inner periphery of a grinding wheel, providing a circular groove around the taper hole section, and making the taper hole section expandable in diameter. CONSTITUTION:A clearance groove 23 is provided on a grinding wheel fitting section at the portion about 1/3 from a flange face 22 side, a taper shaft section 21T is formed on the flange face 22 side from the clearance groove 23, and a straight shaft section 21S is formed on the opposite side. A straight hole section 31S and a taper hole section 31T corresponding to the straight shaft section 21S and taper shaft section 21T are provided on the inner periphery of a grinding wheel 3. A clearance of several mum is provided between the straight shaft section 21S and the straight hole section 31S. The taper hole section 31T is made small in diameter and expandable by a circular groove 33 so that a clearance of about 100mum is generated between the side face 32 of the grinding wheel 3 and the flange face 22 when the taper hole section 31S and taper shaft section 21S are kept at the contact state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which a grindstone is detachably held by a spindle such as a grinder.

[0002]

2. Description of the Related Art A grindstone held on a spindle of a grinder or the like needs to be replaced due to a change in grinding accuracy or wear. Therefore, it is desired that the grindstone be detachably held on the spindle. As a mechanism for detachably holding the grindstone with respect to the spindle in this way, for example, Japanese Patent Publication No. 5-6
According to Japanese Patent No. 1074, a state in which a straight grindstone mounting portion and a flange that rises at a right angle to the rotation axis are sequentially provided from the end surface side on the circumferential surface of the spindle rotating shaft, and the grindstone is fitted to the grindstone mounting portion. Then, move the wedge provided at one place on the peripheral surface of the grindstone mounting portion, press the grindstone toward the one side in the diametrical direction with respect to the grindstone mounting portion, and further use a disk-shaped member to end face of the spindle rotation shaft. It is known that a grindstone is pushed from the side and the side surface of the grindstone is pressed against the flange.

[0003]

In the above conventional case,
A slight clearance must be provided between the grindstone mounting portion and the inner peripheral surface of the grindstone, and when the grindstone is pressed in the diametrical direction, the rotational axis of the grindstone is eccentric to the rotational axis of the spindle by the clearance. Incidentally, it is possible to anticipate the eccentricity due to the clearance in advance, and it is also possible to set so that the eccentricity disappears when the grindstone is pressed against the grindstone mounting portion, but the elastic deformation amount of the grindstone or the rotary shaft depends on the magnitude of this pressing force. Unlike this, it is impossible to reliably prevent eccentricity.

When the grindstone is eccentric as described above, it is conceivable that the outer peripheral surface of the grindstone is scraped off for truing while being held by the spindle. However, when truing cannot be performed like the single-layer electrodeposition grindstone. When the grindstone layer is thin, it is desired that the grindstone is not eccentric to the rotation axis when the grindstone is attached.

Incidentally, by applying the one described in Japanese Patent Publication No. 32-6699, the grindstone holding portion and the inner peripheral surface of the grindstone are formed in a tapered shape whose diameter is reduced toward the end face side of the rotary shaft. It is conceivable to provide an annular groove surrounding the tapered hole portion of the grindstone, and to attach the grindstone to the grindstone holding portion by expanding the diameter of the tapered hole part by elastic deformation by the annular groove,
Since there is a limit to the depth of the annular groove in order to secure the mechanical strength of the grindstone, the tapered portion cannot be formed long in the axial direction, and it is difficult to prevent the grindstone from tilting.

In view of the above problems, it is an object of the present invention to provide a whetstone holding structure in which the whetstone does not fall and the whetstone does not decenter with respect to the rotation axis.

[0007]

In order to achieve the above object, the invention of claim 1 provides a grindstone mounting portion and a flange which rises at a right angle to the rotation axis on the peripheral surface of the end of the rotation axis of the spindle. In a structure in which the grindstone is sequentially provided from the end face side, and the grindstone is fitted and fixed to the grindstone mounting portion so that the side surface of the grindstone is pressed against the flange, and the grindstone is held by the spindle, the grindstone holding portion has a straight shaft portion and a rotary shaft. The taper shaft part that reduces its diameter toward the end face side of the grindstone is provided, and the straight shaft part on the inner peripheral surface of the grindstone has a small clearance between the straight hole and the side face of the grindstone. A grindstone is provided with an annular groove that forms a taper hole portion that abuts the taper shaft portion in the state where there is a gap, and that surrounds the taper hole portion and allows the diameter expansion by elastic deformation of the taper hole portion. Characterize.

According to a second aspect of the present invention, in the first aspect of the invention, the first balance adjusting means for adjusting the rotational balance of the grindstone alone and the second balance for adjusting the rotational balance with the grindstone held on the spindle. An adjusting means is provided.

[0009]

According to the first aspect of the invention, when the grindstone is mounted on the rotary shaft, the grindstone is guided by the cooperation of the straight shaft portion and the straight hole so that the grindstone does not fall with respect to the rotary axis line. When the grindstone is fastened so as to be in close contact with the flange, the tapered hole portion is expanded in diameter by elastic deformation, and the eccentricity of the grindstone is prevented by the cooperation of the tapered shaft portion and the tapered hole portion.

If the grindstone, the rotary shaft and other rotary systems are not balanced, the outer peripheral surface of the grindstone vibrates even if the grindstone is not eccentric, and high precision machining cannot be performed. Therefore, as in the second aspect of the invention, the vibration balance of the outer peripheral surface of the grindstone is suppressed by preliminarily adjusting the rotation balance of the grindstone alone and then again adjusting the whole rotation balance in the state of being attached to the rotary shaft.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, reference numeral 1 is a spindle shaft of a spindle of a grinding machine, and an adapter 2 is fitted to a taper portion 11 formed at a tip end thereof, and a screw portion formed at a tip end of a spindle shaft 1. The adapter 2 is integrally fixed to the spindle shaft 1 by a nut 13 that is screwed into the shaft 12, and the spindle shaft 1 and the adapter 2 form a rotary shaft. On the outer peripheral surface of the adapter 2, a grindstone mounting portion 21 and a flange surface 22 perpendicular to the rotation axis of the spindle shaft 1 are sequentially formed from the tip end side of the spindle shaft 1. Then, in a state where the inner peripheral surface 31 of the metal-made grindstone wheel 3 to which the grindstone G is adhered on the outer peripheral surface is fitted to the grindstone mounting portion 21, and the side surface 32 of the grindstone wheel 3 is in contact with the flange surface 22. The whetstone wheel 3 is fastened to the adapter 2 by the bolt 4.
Reference numeral 5 denotes an embedding bolt which is a first balance adjusting means and is screwed to the grindstone wheel 3 at equal intervals on the same circumference and before the grindstone wheel 3 is attached to the adapter 2. The length is adjusted to adjust the rotation balance of the foil 3 alone. Further, reference numeral 24 is a guide portion formed in a taper shape and serves as a guide when the grindstone wheel 3 is fitted into the grindstone mounting portion 21.

The detailed shapes of the grindstone mounting portion 21 and the inner peripheral surface 31 of the grindstone wheel 3 will be described with reference to FIG. 2. In the grindstone mounting portion 21, there is a clearance groove from the flange surface 22 side to a portion of about 1/3. 23 is provided, and the flange surface 22 is
The side was the taper shaft portion 21T, and the remaining portion was the straight shaft portion 21S. The taper shaft portion 21T has a flange surface 22.
It is formed so as to decrease in diameter from the side toward the escape groove 23 at a taper angle of 2 ° 16 '. On the other hand, on the inner peripheral surface 31 of the grindstone wheel 3, the straight shaft portion 21S and the taper shaft portion 21T are provided.
Straight hole 31S and taper hole 31T corresponding to
And are formed. It should be noted that the straight hole portion 31S has a clearance of several μm to several tens of μm formed between the straight shaft portion 21S and the straight hole portion 31S.
Is formed to have a larger diameter than the straight shaft portion 21S, and the taper shaft portion 21T and the taper hole portion 31T are in contact with each other between the side surface 32 of the grindstone wheel 3 and the flange surface 22.
The tapered hole portion 31T is formed to have a smaller diameter than the tapered shaft portion 21T so that a clearance of about 0 μm is formed. In addition, the grindstone wheel 3 is provided with an annular groove 33 surrounding the tapered hole portion 31T with a wall thickness of about 5 mm from the side surface 32 side.

When the whetstone wheel 3 having the above structure is attached to the adapter 2, the whetstone wheel 3 whose rotation balance has been adjusted in advance by adjusting the length of the embedding bolt 5 as described above is attached to the whetstone mounting portion 21. At this time, the straight shaft portion 21S
By collaborating with the straight hole portion 31S, the grindstone wheel 3 is prevented from falling down, and the grindstone wheel 3 is close to the flange surface 22 without tilting with respect to the axis of the spindle shaft 1 and faces the gap. Next, with the bolt 4, the flange surface 22
The side surface 32 is brought into close contact with. At this time, since the tapered hole portion 31T is provided with the annular groove 33, it is elastically deformed to expand the diameter and prevent the eccentricity of the grindstone wheel 3. The boundary 31P between the straight hole portion 31S and the tapered hole portion 31T may be displaced in the lateral direction due to a processing error. Particularly, when the boundary 31P is displaced toward the tapered hole portion 31T, the straight hole portion 31S is straightened.
Rides on the taper shaft portion 21T and the side surface 3 on the flange surface 22.
2 may not come into close contact with each other, but if the escape groove 23 is provided and the boundary 31P is located in the escape groove 23 as in this embodiment, such a problem does not occur. Therefore, although the relief groove 23 is provided on the grindstone mounting portion 21 side in the present embodiment, the same effect can be obtained by providing relief grooves having a predetermined width on both sides from the position where the boundary 31P is formed on the inner peripheral surface 31 side. To be

When the grindstone wheel 3 is attached in this way, a phase sensor for detecting the rotational phase of the grindstone wheel 3 and a vibration sensor for detecting the vibration of the spindle are attached, and the spindle shaft 1 is rotated at a predetermined rotational speed. The rotation balance of the entire spindle with the grindstone wheel 3 attached is measured. If they are not balanced, each bolt 4 is used as a second balance adjusting means to adjust the length of each bolt 4 to adjust the rotational balance of the entire spindle. When the adjustment of the entire rotational balance is completed in this way, each sensor is removed and grinding is performed.

Although not shown, the grindstone wheel 3 is provided with screw holes through which holes are formed as so-called taps in advance, and the grindstone wheel 3 is removed from the adapter 2 when the life of the grindstone G reaches a new value. Replace with 3.

With respect to the adapter 2, 25 is a spiral groove for preventing the abrasive from entering the spindle.

[0017]

As is apparent from the above description, according to the present invention, when the grindstone is mounted on the rotary shaft, the grindstone is guided by the straight portion of the grindstone mounting portion so that the grindstone does not fall down with respect to the rotary axis. The fall of the rotation axis is prevented.
Further, when the grindstone is brought into close contact with the flange, the tapered hole portion is expanded in diameter by elastic deformation, and the eccentricity of the grindstone is prevented by the cooperation of the tapered shaft portion and the tapered hole portion.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is a partially enlarged view for explaining a detailed shape of a grindstone mounting portion.

[Explanation of symbols]

 1 spindle shaft 2 adapter 3 grindstone wheel 4 bolt (second balance adjusting means) 5 embedding bolt (first balance adjusting means) 21 grindstone mounting portion 22 flange surface 33 annular groove 21S straight shaft portion 21T taper shaft portion 31S straight hole portion 31T taper hole

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[Procedure amendment]

[Submission date] February 9, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In order to achieve the above object, the invention of claim 1 provides a grindstone mounting portion and a flange which rises at a right angle to the rotation axis on the peripheral surface of the end of the rotation axis of the spindle. In the structure in which the grindstone is sequentially provided from the end face side, the grindstone is fitted and fixed to the grindstone mounting portion so that the side surface of the grindstone is pressed against the flange, and the grindstone is held by the spindle.
The mounting part is provided with a straight shaft part and a taper shaft part that reduces in diameter toward the end face side of the rotary shaft, and the straight hole part and the grindstone that face each other with a small clearance on the straight shaft part on the inner peripheral surface of the grindstone. A taper hole portion that abuts the taper shaft portion with a small clearance between the side surface and the flange, and surrounds the taper hole portion to allow a diameter expansion due to elastic deformation of the taper hole portion. It is characterized in that an annular groove is provided in the grindstone.

Claims (2)

[Claims] 1. A grindstone mounting portion and a flange standing upright at right angles to the rotation axis are sequentially provided on an end peripheral surface of a rotary shaft of a spindle from the end face side, and the grindstone is pressed against the side surface of the grindstone. As described above, in the structure in which the grindstone is fitted and fixed to the grindstone mounting portion and the spindle holds the grindstone, the grindstone holding section is provided with a straight shaft portion and a taper shaft portion whose diameter decreases toward the end face side of the rotary shaft, and The inner peripheral surface is formed with a straight hole portion facing the straight shaft portion with a small clearance and a taper hole portion abutting the taper shaft portion with a small clearance between the side surface of the grindstone and the flange. A grindstone holding structure characterized in that the grindstone is provided with an annular groove that surrounds the tapered hole and allows a diameter expansion due to elastic deformation of the tapered hole. 2. A first balance adjusting means for adjusting the rotational balance of the grindstone alone, and a second balance adjusting means for adjusting the rotational balance of the grindstone held by the spindle. Item 1. The grindstone holding mechanism according to Item 1.