JPH07205020A - Spindle device equipped with grinding wheel automatic exchanging device - Google Patents

Abstract

PURPOSE:To provide a spindle device equipped with a grinding wheel automatic exchanging device capable of highly accurately moving a grinding wheel shaft spindle and surely exchanging grinding wheels without needing to make position alignment between the grinding wheel shaft spindle and the grinding wheel automatic exchanging device and without generating any grinding wheel slackness, etc. CONSTITUTION:A bar member 114 is energized in a right direction by a clamp spring 122, a sperical tip part 116 thereof is engaged with the clamping locking part 109 of a grinding wheel tool and thereby the grinding wheel tool is held on a rotary shaft 110. Liquid pressure in a second cylinder chamber 142 is increased, a piston member 134 is moved in a left direction and the bar member 114 is pressed and moved in a left direction by the locking end 154 of the tip thereof. Thus, the tip part 116 is opened, the front end of a quill pushing out member 123 inside a rod 115 is made to abut on the rear end of a tapered quill 107, the tapered quill 107 is pushed out and a grinding wheel tool 68 is allowed to be removed from the rotary shaft 110.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device with an automatic grindstone exchanging device, and more particularly to a spindle device with an automatic grindstone exchanging device.

[0002]

2. Description of the Related Art In a grinding machine, a grindstone is crushed or clogged due to processing, so that the grindstone needs to be dressed regularly, which reduces the diameter of the grindstone. Since it is necessary to regularly replace the grindstone when the grindstone usage limit is reached, the grinder is provided with an automatic grindstone exchanging device for automatically exchanging the grindstone of the grindstone spindle. Since the automatic whetstone changing device attaches the whetstone to the chuck on the side of the whetstone spindle by the operation of its arm, it is necessary to devise its attachment method when automating the replacement work. Was there. 7A, 7B, and 8A,
(B) shows the attachment / detachment portions of the grindstone and the chuck in the conventional grinding machine. In the structure shown in FIG. 7 (A), the shank 12 of the grindstone 10 is formed with the male screw portion 14, and the chuck 16 attached to the rotating shaft of the grindstone spindle is formed with the female screw portion 18 that is screwed with the chuck 16. There is. Further, a hexagonal wrench hole 20 is provided on the head of the shank 12, and a hexagonal wrench portion 24 provided on the tip end portion 22 of the arm of the automatic grindstone changing device can be inserted. There is. Grinding stone 1 for chuck 16
The hexagonal wrench 24 is used to attach and detach 0
Are rotated with respect to the chuck 16.

In the structure shown in FIG. 7B, a sliding member 32, which is slidable in the radial direction, is disposed inside the centrifugal chuck 30 with one end pulled by a spring 34. The grindstone is attached by inserting the centrifugal chuck 30 into the hole provided at the tip of the shank by the arm of the automatic grindstone changing device. The sliding member 32 is the centrifugal chuck 30.
When is rotated, it moves in the direction of arrow a due to the centrifugal force.
Therefore, with the grindstone attached, this sliding member 32
Presses the inner peripheral surface of the hole in the shank of the grindstone. As a result, the grindstone is fixed to the centrifugal chuck 30. In the case shown in FIG. 8A, the chuck 40 is attached to the grindstone 4.
The grindstone 42 is fixed by being press-fitted into the second through hole 44. Further, in the one shown in (B) (collet chuck), the collet 47 is inserted and arranged in the center hole of the tubular member 46 provided with the taper 45. Whetstone 48 is collet 4
7, the collet 47 is pulled by an air cylinder or the like as shown by an arrow b, so that a narrow pressure is maintained.

[0004]

In the method shown in FIG. 7 (A), a mechanism for rotating the hexagonal wrench portion 24 is required for the arm of the automatic grindstone exchanging device, which complicates the structure of the arm. The grindstone automatic changer becomes large. In general, the grinding process may be performed while reciprocally moving (oscillating, etc.) a grindstone, and therefore, in a grinding machine, a grindstone spindle is placed on a reciprocating moving table. For the moving table of this grindstone spindle,
It is conceivable that the grindstone automatic exchanging device is also placed and moved integrally, but in the conventional technique shown in FIG. 7A, the grindstone automatic exchanging device becomes large in size.
When mounted on two moving tables, an excessive load is applied to the drive system of the moving tables, and especially when reciprocating at a high speed, the movement accuracy of the moving tables deteriorates. Therefore, in the conventional technique shown in FIG. 7 (A), the grindstone automatic exchanging device and the grindstone spindle are placed on different tables. However, in this case, when replacing the grindstone 10, NC
The position of each moving table must be controlled using a device (numerical control device) to align the grinding wheel spindle and the automatic grinding wheel changing device.

The method shown in FIG. 7B does not require a rotating mechanism in the arm of the automatic grindstone exchanging device, but the movement of the sliding member 32 may cause imbalance during rotation. Since the centrifugal force acting on the sliding member 32 becomes small at the time of stopping, there is also a problem that the grindstone loosens. Further, the method shown in FIG. 8A has a problem that the chuck 40 is welded to the through hole 44 by the heat during grinding, and the method shown in FIG. Since the part is cylindrical, the holding force of the collet 47 is weak. Further, since the collet 47 must be constantly pulled during the rotation, there is a problem that the grindstone 48 is loosened due to the pressure drop of the air cylinder.

Therefore, an object of the present invention is to allow the grindstone spindle to move with high accuracy of movement, and to prevent loosening of the grindstone without aligning the grindstone spindle with the grindstone automatic exchanging device. It is an object of the present invention to provide a spindle device with a grindstone automatic exchanging device capable of performing reliable grindstone replacement.

[0007]

According to a first aspect of the present invention, there is provided a stocker for accommodating a plurality of grinding wheel quills in which a grinding wheel is integrally fixed and a tapered portion and a stepped portion for reducing a diameter on a tip end side are formed. A rotary shaft having an axially formed quill holding hole having a tapered portion into which the tapered portion of the grinding wheel quill is fitted; and a radial direction in which the quill holding hole of the rotating shaft projects inward from an inner peripheral surface of the quill holding hole. Whetstone spindle having a possible projecting member and quill holding means for pressing the projecting member toward the center in a state where the whetstone quill is inserted in the quill holding hole to engage and hold the step portion of the whetstone quill And a grindstone conveying means for conveying the grindstone quill stored in the stocker and inserting it into the quill holding hole of the rotary shaft and for removing the grindstone quill inserted therein and returning it to the stocker, and the grindstone conveying means. Together with the wheel spindle spindle and said stocker is placed, it was provided with a moving means for moving integrally with the grinding wheel autochanger with the spindle apparatus to achieve the above purpose.

[0008]

In the spindle device with the automatic grindstone changing device according to the first aspect, the grindstone conveying means conveys the grindstone quill stored in the stocker and inserts it into the quill holding hole of the rotary shaft. As a result, the tapered portion of the whetstone quill fits into the tapered portion of the quill holding hole. The quill holding means presses the protruding member toward the center of the quill holding hole to engage the protruding member with the stepped portion of the inserted grinding stone quill and hold the grinding stone quill. The grindstone conveying means, the grindstone spindle and the stocker are moved integrally by the moving means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spindle device with an automatic grindstone changing device of the present invention will be described in detail below with reference to FIGS. 1 to 3 show the overall configuration of a spindle device with a grindstone automatic changing device according to this embodiment. As shown in FIG. 1, a spindle device 50 with an automatic grindstone changing device and a grindstone spindle 5 according to this embodiment.
2, a stocker 70 in which a plurality of replacement grindstone tools 68 are stored, conveyance of the grindstone tools 68, and a grindstone spindle 5
2, a grindstone transfer device 54 for attachment to the No. 2 and a grindstone table 62 that reciprocates by a drive mechanism (not shown) such as a ball screw or a servomotor.

As shown in FIG. 3, the stocker 70 has a disk shape, and a stocker mounting support plate 66 supported by two support plates 64 and 65 fixed on the grindstone table 62. It is rotatably mounted on the fixed shaft 72 (FIG. 2). The stocker 70 is provided with a tool holding hole 76 all around the stocker 70, and the replacement grindstone tool 68 is stored by being inserted into the tool holding hole 76. A locking pin 78 protruding downward is attached to the outer periphery of the stocker 70. The locking pins 78 are provided in the same number as the tool holding holes 76 at positions corresponding to the tool holding holes 76, respectively.

On the stocker mounting support plate 66, there are fixed a stocker pitch feed cylinder 82 for advancing and retracting a movable member 80 having an inclined end and a stocker positioning cylinder 86 for advancing and retracting the movable member 84. The stocker positioning cylinder 86 moves the movable member 84 as shown by the chain double-dashed line in FIG.
The tip end of the locking pin 78 is brought into contact with the locking pin 78, and the locking pin 78 is sent to the position shown by the dotted line. Further, the stocker pitch feed cylinder 82 moves the movable member 80 from the position indicated by the chain double-dashed line to the position indicated by the solid line, thereby moving the locking pin 78 from the position indicated by the dotted line to the position further indicated by the solid line. Has become. This allows the stocker 7
0 is rotated at a pitch for feeding one tool holding hole 76 in the direction of arrow j in FIG.

The grindstone transfer device 54 includes a revolving arm 90 having a gripper 88 sandwiching the grindstone tool 68 at its tip.
The rotary arm 90 has a rotary drive mechanism 92 for rotating the rotary arm 90 as shown by arrows c and d in FIG. The rotary drive mechanism 92 is fixed to a fixed plate 94.
The unit 4 is moved by a unit forward / backward moving cylinder 96 in the directions of arrows e and f by a predetermined distance. Further, the moving table 98 to which the unit forward / backward moving cylinder 96 is fixed is moved by a unit vertical cylinder 100 (shown by a dotted line in FIG. 1) fixed to the support plate 65 in a predetermined distance in the directions of arrows g and h. It has become. Therefore, the revolving arm 90 is horizontally moved by the unit forward / rearward movement cylinder 96 and is vertically moved by the unit up / down cylinder 100. In the present embodiment, the grindstone transfer device 54, the stocker 70, and the like described above constitute an automatic grindstone exchanging device for automatically exchanging the grindstone tool 68 of the grindstone spindle 52. The position indicated by the chain double-dashed line in FIG. 1 is the original position of the swivel arm 90. The grindstone spindle 52 is fixed on the grindstone table 62 by the grindstone 102.

FIG. 4 shows the internal structure of the grindstone spindle 52. In the following description, the left side in FIG. 4 is the front and the right side is the rear. First, the structure of the grindstone tool 68 will be described with reference to this drawing. The grindstone tool 68 is the shank 10 to which the cylindrical grindstone 105 is attached.
6 is integrally fixed to the taper quill 107. The taper quill 107 has a large-diameter portion 107a that is held by the gripper 88 of the swivel arm 90, and a taper portion 108 that has a diameter that decreases from the front side to the rear side. Further, the taper quill 107 has a small diameter portion 107b having the smallest diameter and a clamp locking portion 109 having a diameter larger than that of the small diameter portion 107b.

Next, the grindstone spindle 52 will be described. The grindstone spindle 52 includes a spindle portion 52A for rotating the rotary shaft 110 and the spindle portion 5A.
2A and a cylinder portion 52B attached to the rear end portion thereof. The rotary shaft 110 of the spindle portion 52A is supported by bearings 53 and 55, and is rotationally driven by a motor 59 arranged on the outer periphery thereof. In this embodiment, the rotary shaft 110 is formed with a through hole 112 penetrating in the front-rear direction. This through hole 1
A taper 113 having an inclination angle similar to that of the taper portion 108 of the taper quill 107 in the grindstone tool 68 is formed in the front opening portion of 12. In the state shown in FIG. 4, the grindstone tool 68 is inserted into the through hole 112 so that the taper 113 and the taper portion 108 of the taper quill 107 are fitted together. On the right side of the taper 113, the annular recess 111 is formed by increasing the diameter.

A rod member 114 is slidably inserted in the through hole 112. This rod member 114
Is a plurality of (for example, three) rods 1 at the front end.
It is divided into 15, and a tubular quill pushing member 123 is attached to the inside thereof. Rod 11
Each of the front end portions 116 of No. 5 has a substantially spherical shape. The rod 115 has a tip portion 11 when there is no external force.
6 are separated from each other as compared with the state shown in FIG. However, in the state shown in FIG. 4, since the distal end portion 116 is pressed inward by the inner peripheral surface of the through hole 112, it is elastically deformed and brought into a state of being close to each other (closed state). As shown in FIG. 4, when the grindstone tool 68 is inserted into the through hole 112, the tip portion 116 is engaged with the clamp locking portion 109 of the taper quill 107 (hereinafter, this state is referred to as a “clamp state”). That). In addition,
The rear end portion 117 of the rod member 114 projects rearward from the rear end of the rotary shaft 110.

The rod member 114 is formed with a locking portion 118 which is in contact with the inner peripheral surface of the through hole 112. A clamp spring 122 having both ends locked by locking rings 120 and 121 is disposed between the locking portion 118 and the step 119 of the through hole 112. The rod member 114 is biased rearward by the clamp spring 122. Therefore, the tip 116 of the rod member 114 is
The taper quill 107 is clamped and pulled rearward, so that the grindstone tool 68 moves the rotary shaft 11
It is fixed at 0.

On the other hand, the cylinder part 52B has a piston part 132 as a pressure receiving part and rod parts 130 and 131 before and after the piston part 132.
It is equipped with 4. The piston member 134 has a small diameter hole 1 in which the rod portion 130 is provided in the cylinder block 136.
35, the rod part 131 closes the central hole 137 of the closing member 138 that closes the rear end opening of the cylinder block 136.
Are slidably inserted therein. Piston part 1
Before and after 32, a first cylinder chamber 140 and a second cylinder chamber 142 are formed by the cylinder block 136 and the closing member 138, respectively. The first cylinder chamber 140 and the second cylinder chamber 142 are filled with oil, and pressure is applied from respective hydraulic pressure supply ports 144 and 146 by a pump (not shown).
In addition, the first cylinder chamber 140 and the second cylinder chamber 142
Is an O-ring 1 arranged on the outer periphery of the piston portion 132.
41, the O-ring 143 arranged in the small-diameter hole 135 of the cylinder block 136, and the O-ring 145 arranged in the closing member 138 maintain liquid tightness.

The hydraulic pressure in the first cylinder chamber 140 pushes the piston portion 132 rearward, and the hydraulic pressure in the second cylinder chamber 142 pushes the piston portion 132 forward. Therefore,
The piston member 134 is moved back and forth by these pressure differences. In the state shown in FIG. 4, the hydraulic pressure in the second cylinder chamber 142 is greater than that in the first cylinder chamber 14.
Higher than that of zero, the piston member 134 is in the rearmost position. The piston member 134 is formed with a piston through hole 150 penetrating therethrough in the front and rear thereof. A shaft center member 152 having both ends projecting forward and backward is slidably inserted into the piston through hole 150. ing. The rod portion 1 is provided at the front end of the shaft center member 152.
A locking end 154 having a diameter substantially equal to the outer diameter of 30 is provided,
On the other hand, at the front end of the piston through hole 150, the diameter is formed larger than the outer diameter of the shaft center member 152. A compression spring 158 is arranged between the stepped portion 156 located at the rear end of the large diameter portion of the piston through hole 150 and the locking end 154 of the shaft center member 152. In the state shown in FIG. 4, the urging force of the compression spring 158 causes the axial center member 1 to move.
The stopper ring 160 attached to the rear end of 52 is
The shaft portion 152 is in contact with the rear end of the rod portion 131.
Is in the most forward position with respect to the piston member 134.

The locking end 154 of the shaft center member 152 faces the rear end portion 117 of the rod member 114 with a gap P therebetween. This gap P is sufficiently smaller than the stroke Q of the piston member 134 in the forward and backward movements, and the forward movement of the piston member 134 causes the locking end 154 to come into contact with the rear end portion 117. In addition, the first cylinder chamber 140 and the second cylinder chamber 142 are calculated by adding the urging force of the compression spring 158 and the urging force of the clamp spring 122.
The forward pressing force on the piston member 134 due to the differential pressure is set to be sufficiently large. Therefore,
The locking end 154 that abuts the rear end portion 117 has the compression spring 15
8 and the clamp spring 122 are compressed, the rod member 114 is moved forward by a predetermined distance.

FIG. 5 shows the grindstone spindle 52 when the rod member 114 moves forward by a predetermined distance. As shown in this figure, the rod member 114 has the shaft center member 15
When the rod 115, which is elastically deformed inward, is moved forward by 2, the spherical tip end portion 116 of the rod 115 is housed in the annular recess 111 of the through hole 112, and the rod 115 is opened. Therefore, the clamp locking portion 10 by the tip portion 116.
The clamped state of No. 9 is released (hereinafter, this state is referred to as “unclamped state”), and at the same time, the front end of the quill pushing member 123 in the inner diameter of the rod 115 comes into contact with the rear end of the tapered quill 107, and the second cylinder chamber The taper quill 107 is pushed out by the pressure of 142. As a result, the grindstone tool 68 can be removed from the rotary shaft 110.

Next, the operation of the embodiment thus constructed will be described. The rotary shaft 110 of the grindstone spindle 52 has a grindstone tool 68 that has been machined for a predetermined time.
It is assumed that the grindstone tool 68 is not held by the gripper 88 of the revolving arm 90. Further, the grindstone shaft spindle 52 stops the rotation of the rotary shaft 110. First, the revolving arm 90 is rotated by 180 ° in the arrow d direction from the original position indicated by the chain double-dashed line in FIG. 1 by the rotation drive mechanism 92. Then, the swing arm 90 is moved in the direction of arrow e by the unit forward / backward movement cylinder 96, and further, the unit vertical cylinder 100 is moved.
By descending in the direction of arrow g, the gripper 88
Grips the large diameter portion 107 a of the taper quill 107 of the grindstone tool 68 attached to the rotary shaft 110.

Next, in the grindstone spindle 52, the inside of the first cylinder chamber 140 is decompressed, and a predetermined hydraulic pressure is applied inside the second cylinder chamber 142, so that the piston member 1
34 moves forward from the position shown in FIG. Then, the locking end 154 presses the rear end portion 117 of the rod member 114 and moves the rod member 114 to open the tip end portion 116 thereof as shown in FIG. at the same time,
The front end of the quill pushing member 123 in the inner diameter of the rod 115 contacts the rear end of the taper quill 107, and pushes out the taper quill 107. As a result, the taper quill 107 of the grindstone tool 68 is unclamped. Subsequently, the revolving arm 90 moves in the direction of arrow f in FIG. 1 with the grinder 88 holding the grindstone tool 68. As a result, the grindstone tool 68 is separated from the rotary shaft 110. Then, the swing arm 90 rises in the direction of the arrow h, and further,
By rotating 180 ° in the direction of arrow c, it returns to the original position.

Next, the revolving arm 90 moves in the direction of arrow e until the held grindstone tool 68 is positioned on the tool holding hole 76 of the stocker 70. At this time, the grindstone tool 68 is not stocked in the tool holding hole 76 located immediately below the gripper 88, and the turning arm 90 descends to insert the grindstone tool 68 into the tool holding hole 76.
When the used grindstone tool 68 is stored in the stocker 70, the gripper 88 moves in the f direction and releases the grindstone tool 68. Then, the swing arm 90 moves in the h direction,
Return to the original position again. Subsequently, the stocker positioning cylinder 86 and the stocker pitch feed cylinder 82 alternately move the movable member 84 and the movable member 80 back and forth, whereby the stocker 70 rotates by a predetermined pitch. As a result, a new grindstone tool 68 before use is positioned at the position where the grindstone tool 68 that has been used is inserted.

Next, the revolving arm 90 moves in the directions of the arrows g and e, grabs the new grindstone tool 68 with the gripper 88, similarly raises, retracts and rotates, and further moves in the directions of the arrows g and e. Thus, the new grindstone tool 68 is inserted into the rotary shaft 110 of the grindstone spindle 52. Then, the second cylinder chamber 142 is depressurized and the hydraulic pressure in the first cylinder chamber 140 is increased to retract the piston member 134. As a result, the rod member 114 is urged by the clamp spring 122 from the position shown in FIG.
Move to the position shown in, and use the tip 116 of the grindstone tool 68.
Clamp the taper quill 107. When the grindstone tool 68 is held, the revolving arm 90 returns to the original position, and the replacement work of the grindstone tool 68 in the grindstone shaft spindle 52 is completed.

As described above, in this embodiment, since the automatic grindstone exchanging device is installed on the grindstone table 62 together with the grindstone spindle 54, the grindstone does not need to be aligned with the NC device. The tool 68 can be automatically replaced. Further, since the mechanism for clamping the taper quill 107 of the grindstone tool 68 is provided in the grindstone spindle 52, the turning arm 90 of the grindstone transfer device 54 is simplified and the grindstone automatic exchanging device is downsized. It is possible to prevent a decrease in motion accuracy when the 62 is reciprocated. Further, in this embodiment, the tapered quill 107 of the grindstone tool 68 is provided with the tapered portion 108, and
The taper 113 fitted to this is provided on the rotating shaft 110 side,
Moreover, since the grindstone tool 68 inserted into the through hole 112 is pulled by the urging force of the clamp spring 122, the grindstone tool 68 is stably held on the rotating shaft 110 without loosening.

In the above embodiment, the tip portion 116 of the rod 115 of the rod member 114 is formed into a spherical shape so that the clamp engaging portion 109 of the taper quill 107 is pulled, but the tip portion 116 is Other shapes may be used as long as they project inward. Also, for example,
The taper quill 107 'may be clamped by other structures, such as the structure shown in FIG. In the structure shown in FIG. 6, instead of the tip portion 116 of the rod member 114, the ball 1
A ball holding hole 172 for accommodating the ball 70 is provided in the rotary shaft 174, and the ball 170 is inserted from the outside thereof.
The sleeve 176 is fitted so as to be pushed in. As a result, the ball 170 engages with the clamp engaging portion 109 'of the taper quill 107'.
The sleeve 176 is rotated by the compression spring 178.
4 is urged in the direction of the arrow k with respect to
Is pressing. Also, the sleeve 176 is slid in the direction of the arrow r to open the ball 170 and bring the taper quill 107 'into an unclamped state. Further, although the cylinder portion 52B is driven by the oil cylinder in the above embodiment, it may be driven by the air cylinder or may be structured so as to move the piston member 134 back and forth by driving the motor.

[0027]

According to the spindle device with the automatic grindstone exchanging device of the present invention, it is possible to move the grindstone shaft spindle with high motion accuracy, and without aligning the grindstone shaft spindle and the automatic grindstone exchanging device. As a result, it is possible to perform reliable whetstone replacement without causing loosening of the whetstone.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a spindle device with an automatic grindstone changing device of the present invention.

FIG. 2 is a side sectional view of the device.

FIG. 3 is a plan view of the device.

FIG. 4 is a front view showing a cross section when the grindstone spindle of the apparatus is in a clamped state.

FIG. 5 is a front view showing a cross section when the grindstone spindle of the apparatus is in an unclamped state.

FIG. 6 is a cross-sectional view showing a modified example of the device.

FIG. 7 is an explanatory view showing a portion for attaching and detaching a grindstone in a conventional grinding machine.

FIG. 8 is an explanatory diagram showing a mounting / dismounting portion of a grindstone in a conventional grinding machine.

[Explanation of symbols]

 50 Spindle device with automatic grindstone exchanging device 52 Grindstone shaft spindle 52A Spindle part 52B Cylinder part 62 Grindstone table 68 Grindstone tool 70 Stocker 76 Tool holding hole 82 Stocker pitch feed cylinder 86 Stocker positioning cylinder 88 Gripper 90 Swivel arm 92 Rotational drive mechanism 96 Unit forward / backward cylinder 100 Unit up / down cylinder 107, 107 'Tapered quill 108 Tapered part 109 109' Clamping locking part 110 Rotating shaft 111 Annular recess 112 Through hole 113 Tapered 114 Bar member 115 Rod 116 Tip part 122 Clamp spring 123 Quill extrusion Member 134 Piston member 140 First cylinder chamber 142 Second cylinder chamber 142 152 Shaft center member 154 Locking end 158 Compression spring 170 Baud 172 ball holding hole 174 rotating shaft 176 sleeve 178 a compression spring

Front page continuation (72) Inventor Muroi Tsunechu, 62, Chikusa-cho, Hanamigawa-ku, Chiba, Chiba High Tech Seiko Co., Ltd. (72) Hideyuki Iwabata, 62, Chikusa-cho, Hanamigawa-ku, Chiba, Chiba Within

Claims (1)

[Claims] 1. A stocker in which a grindstone is integrally fixed and has a taper portion that reduces a diameter on a tip end side thereof, and a stocker that stores a plurality of grindstone quills having step portions, and a taper portion of the grindstone quill is fitted. A rotary shaft having a tapered quill holding hole formed in the axial direction, a projecting member that projects inward from the inner peripheral surface of the quill holding hole of the rotary shaft, and is movable in the radial direction; With the grindstone quill inserted in the hole, a grindstone spindle having quill holding means for pressing the protruding member toward the center and engagingly holding the stepped portion of the grindstone quill, and stored in the stocker. A grindstone conveying means that conveys the grindstone quill, inserts it into the quill holding hole of the rotary shaft, and removes the inserted grindstone quill and returns it to the stocker, the grindstone conveying means, the grindstone spindle, and the front. A spindle device with an automatic grindstone exchanging device, comprising: a stocker and a moving means for moving them integrally.