JP3406044B2 - Dial gauge centering device - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a machining center,
A dial type centering device that is attached to the spindle of a machine tool such as a general-purpose milling machine or boring machine to perform centering of the inner diameter or outer diameter of a work.

[0002]

2. Description of the Related Art A conventional dial type centering device of this type is
The main shaft is rotatably mounted in the casing so as to pass through the center of the casing, and the rotation prevention bar of the casing is mounted on the required part of the outer peripheral surface of the casing, and the slide collar is externally fitted to the main shaft so that it can slide in the axial direction. At the same time, the slide collar is urged by a spring in the direction toward the tip of the main spindle, and the tip of the main spindle is pivotally attached to the center of a swing arm having a bar-shaped measuring element protruding from it. Attach the body of the dial gauge to the, the measurement terminal of this dial gauge is brought into contact with the inner end reference surface of the flange portion protruding on the base end side of the main shaft, and the protrusions on both ends of the swing arm are slid on the slide. It is designed to be brought into contact with the outer end surface of the flange portion projecting from the tip portion of the collar.

In using this centering device, the device is attached to a spindle of a machine tool, and a detent bar is locked to a column fixed to a table of the machine tool by a magnetic stand to prevent the detent of the casing. Give.
Then, move the spindle of the machine tool to approximately the center position of the workpiece to be measured, lightly touch the tip of the probe to the measurement surface of the workpiece with your finger, the probe contacts the measurement surface, and the pointer of the dial gauge starts to move. After adjusting with the fine adjustment knob of the gauge, rotate the spindle at a low speed and move the X and Y axes of the machine tool as appropriate so that the pointer does not touch the spindle axis of the workpiece. Can be matched with.

[0004]

In the conventional centering device described above, since the casing is prevented from rotating, the gauge body does not rotate even if the main shaft rotates due to the rotation of the machine tool spindle, and therefore, the gauge main body does not rotate. The measurer can always see the dial gauge pointer display at a fixed position in the circumferential direction of the casing. However, in this centering device, the contact point of the probe contacts the measurement surface of the workpiece and the swing arm swings, so that the slide collar is axially pushed against the spring biasing force, and the slide collar is moved. The dial gauge integrated with the unit moves in the axial direction of the measuring terminal, so that the measuring terminal of the gauge contacts the reference surface of the inner end of the flange of the spindle, and the moving amount of the gauge measuring terminal is displayed by the pointer. Therefore, the gauge body is
Although it is in a fixed position in the circumferential direction of the casing, it moves in the axial direction of the dial gauge measurement terminal with respect to this casing,
There was a problem that the display of the pointer became difficult to see.

In view of the above problems, it is an object of the present invention to provide a dial gauge type centering device capable of performing measurement in an immovable state while keeping the display portion of the gauge stationary at a fixed position.

[0006]

A dial gauge type centering device according to claim 1 of the present invention comprises a casing 1 and a main shaft 4.
Is rotatably attached through the central portion of the casing 1, and the rotation stop lever 8 and the dial gauge 9 of the casing 1 are attached to required portions on the peripheral surface side of the casing 1.
A slide collar 7 is externally fitted to the main shaft 4 so as to be slidable in the axial direction, and the slide collar 7 is interlockingly connected to a measuring terminal shaft 17 provided on the dial gauge 9 so that the slide shaft is provided on the tip side of the main shaft 4. 12 is fitted inside so as to be slidable in the axial direction, the slide shaft 12 and the slide collar 7 are coupled so as to be integrally movable in the axial direction, and the springs 13 and 26 are provided.
The slide shaft 12 is urged by the tip of the main shaft 4 so as to project from the tip of the main shaft 4, and a fixed arm 27 extending laterally from the main shaft 4 is attached to the front end of the main shaft 4, and a fixed end 27b of the fixed arm 27 is attached to the free end 27b. Is the other end 2 of the swing arm 28 in which the tip of the slide shaft 12 abuts on the one end 28a.
8b is pivotally mounted so as to be swingable only within a fixed angle range, and a probe mounting member 29 is pivotally mounted on the one end 28a side of the swing arm 28.

In the dial gauge type centering device according to the second aspect, the slide shaft 12 supports the tip of the slide collar 7 so as to project laterally from the slide shaft 12, and the main shaft 4 for a predetermined stroke within the main shaft 4. The horizontal pin 14 that is movable in the axial direction of the
Is provided between the main shaft 4 and the main shaft 4, and a first spring 13 for urging the slide shaft 12 toward the front end of the main shaft 4 is provided, and an outer peripheral portion of the slide collar 7 is laterally extended from the measurement terminal shaft 17 of the dial gauge 9. An arm receiving pin 24 for receiving the integrally projecting support arm 20 is integrally projectingly provided, and a second spring 26 for urging the support arm 20 together with the arm receiving pin 24 toward the tip end side of the main shaft 4 is provided. Is characterized by.

The dial gauge type centering device according to a third aspect is characterized in that a pivot bearing 33 is interposed between the free end portion 27b of the fixed arm 27 and one end portion of the swing arm 28.

In the dial gauge type centering device according to the fourth aspect, the tracing stylus attachment member 29 is pivotally attached to the one end 28a side of the swing arm 28 by the pivot 36, and is also interposed in the pivot attachment 36. The disc spring 37 prevents the swing arm 28 from rotating below a certain rotational force.

[0010]

According to the first aspect of the present invention, when the rod-shaped probe 30 attached to the probe-attaching member 29 is brought into contact with the measurement surface of a work or the like in an appropriate pressure contact state, and an external force acts on the rod-shaped probe 30. The swing shaft 28 integrally formed with the rod-shaped probe 30 and the probe mounting member 29 swings around a swing fulcrum 33 and projects from the tip of the spindle 4 to the slide shaft 12.
Is pushed against the biasing force of the spring 13. As the slide shaft 12 is pushed, the slide collar 7 moves, the measurement terminal shaft 17 of the dial gauge 9 moves, and the pointer 19 moves. At this time, since the dial gauge 9 is attached to the casing 1, even if the measurement terminal shaft 17 of the dial gauge 9 moves as the slide shaft 12 moves, the gauge 9
The display unit 16a of does not move.

Further, as the spindle 4 is rotated by the rotation of the machine tool spindle and the rod-shaped probe 30 is rotated around the spindle 4 along the measurement surface, the external force acting on the rod-shaped probe 30 changes. When the swing arm 28 swings in the swing range in the opposite direction to the above case, the slide shaft 12 moves toward the tip end side of the main shaft 4 due to the urging force of the spring 13, and the slide collar 7 accordingly. Moves in the same direction, the measurement terminal shaft 17 of the dial gauge 9 moves,
Move the pointer 19. At this time, similarly, the measurement terminal shaft 17
The display portion 16a of the gauge 9 does not move due to the movement. Further, since the casing 1 is prevented from rotating by the rotation stop lever 8, the dial gauge 9 is always held at a fixed position in the circumferential direction.

In the second aspect, the swing arm 28
Swings around the swing fulcrum 33 to move the slide shaft 12 to the first position.
When pushed against the biasing force of the spring 13, the lateral collar 14 supporting the tip of the slide collar 7 causes the slide collar 7 to slide together with the arm receiving pin 24 against the biasing force of the second spring 26. The support arm 20 is pushed by the movement of the arm receiving pin 24 by moving in the same direction as the shaft 12, the measuring terminal shaft 17 of the dial gauge 9 moves, and the pointer 19 swings. When the swing arm 28 swings in the opposite direction, the slide shaft 12 moves toward the tip end side of the main shaft 4 by the urging force of the first spring 13, and the support arm 20 receives the arm receiving force by the urging force of the second spring 26. Slide shaft 12 together with slide collar 7 with pin 24
Move in the same direction, and the tip of the slide collar 7 is a horizontal pin 1.
Abut 4. Then, the measurement terminal shaft 17 of the dial gauge 9 is moved by the movement of the support arm 20, and the pointer 19
Swings.

According to the third aspect of the present invention, the pivot arm 33 is provided between the free end portion 27b of the fixed arm 27 and the one end portion of the swing arm 28. It swings lightly and accurately to move the slide shaft 12 sensitively and delicately.

In the fourth aspect, the tracing stylus attachment member 29
Is rotatable about a pivot 36 with respect to the swing arm 28.
On the other hand, if the rotational force is less than a certain value, it cannot rotate. That is,
The tracing stylus attachment member 29 exerts a rotational force on the swing arm 2 that exceeds the spring force of the disc spring 37, so that the swing arm 2
It becomes possible to rotate with respect to 8. Therefore, the contact piece attachment member 29 can adjust the attachment angle with respect to the swing arm 28 at the same time, and at the same time, can fix it at the adjusted arbitrary angle.

[0015]

EXAMPLES Examples will be described with reference to the drawings.
1 showing an external front view of a dial gauge type centering device according to the present invention and FIG. 2 showing a longitudinal sectional side view thereof,
Reference numeral 1 denotes a cylindrical casing, 2 denotes a fixed sleeve that is concentrically fitted and inserted into the casing 1, and is fixed integrally with the casing 1 by a fixing screw 3. 4 denotes a fixed sleeve 2 that passes through the fixed sleeve 2 concentrically. A main shaft extending so as to project from the upper and lower ends of the fixed sleeve 2 and the casing 1, and is rotatably attached to the casing 1 by thrust and radial load bearings 5 and 6 provided at both front and rear ends of the fixed sleeve 2. ing. Between the main shaft 4 and the fixed sleeve 2, a slide collar 7 fitted on the main shaft 4 is provided.
The outer peripheral surface and the inner peripheral surface of the fixed sleeve 2 are slidably inserted in the axial direction with a minimum required clearance. Further, a rotation stop lever 8 and a dial gauge 9 of the casing 1 are attached to a required portion on the circumferential surface side of the casing 1.

A hollow portion 11 is concentrically provided on the tip end side of the main shaft 4, and the slide shaft 12 is provided in the hollow portion 11.
Is slidably fitted in the axial direction with a minimum play gap, and the slide shaft 12 is provided with a first spring 13 formed of a compression coil spring provided in the inner part of the hollow portion 11 so that the main shaft 4 Is urged to project from the tip of the. Further, on the rear end side of the slide shaft 12, the lateral pin 14
However, the slide shaft 12 is fixed in a state of penetrating the slide shaft 12 in the diametrical direction and projecting longer than the outer diameter of the main shaft 4 and shorter than the outer diameter of the slide collar 7. As shown in FIG. 2, the horizontal pin 14 is movable in the axial direction of the main shaft 4 for a predetermined stroke together with the slide shaft 12 in a horizontal hole 15 penetrating the main shaft 4, and the tip of the slide collar 7 is always present. I support you.

As shown in FIGS. 2 and 6, the dial gauge 9 has a well-known structure composed of a gauge body 16 and a measurement terminal shaft 17 provided so as to be movable relative to the gauge body 16.
The amount of movement of the measuring terminal shaft 17 is enlarged by the gear mechanism 18,
Pointer 19 of the display portion 16a provided on the gauge body 16 side
(See FIG. 1) is used to indicate a minute dimension. As shown in FIG. 6, the measurement terminal shaft 17 is integrally provided with a support arm 20 extending laterally from the terminal shaft 17, and the tip end of the support arm 20 is attached to the gauge main body 1.
A guide groove 21 provided on the 6 side in parallel with the measuring terminal shaft 17.
Will be guided by. The gauge main body 16 of the dial gauge 9 is attached and fixed to the attachment opening 1a penetrating the peripheral wall of the casing 1.

As shown in FIG. 7, a pedestal 22 is fixed to the slide collar 7 at an intermediate portion in the longitudinal direction of the outer peripheral surface thereof with a screw 23. From this pedestal 22, an arm receiving pin 24 is provided.
Are projected integrally in the lateral direction. The pedestal 22 is arranged so as to be housed in a through hole 25 formed through the peripheral wall portion of the fixed sleeve 2 (see FIG. 2), and the arm receiving pin 2
4 projects into the gauge body 16 from the pedestal 22 through the rear side opening O of the gauge body 16 so as to receive the support arm 20 projecting on the measurement terminal shaft 17 of the dial gauge 9, and A second spring 26, which is a compression coil spring for urging the support arm 20 together with the arm receiving pin 24 toward the tip end side of the main shaft 4, is interposed between the support arm 20 and the gauge body 16 of the dial gauge 9. (See FIG. 6). The second spring 26 is the first spring 13
It is possible to use a spring having a sufficiently small spring pressure.

On the other hand, as shown in FIG. 2, a base end portion 27a of a fixed arm 27 extending laterally from the main shaft 4 is attached to the tip end portion of the main shaft 4, and a free end portion 27b of the fixed arm 27 is attached. The other end 28b of the swing arm 28, in which the tip of the slide shaft 12 is in contact with the one end 28a, is pivotally attached so as to be swingable only within a certain angle range.
A probe mounting member 29 is pivotally mounted on the side of one end 28a of 8 so as to be fixed at a required angle, and a rod-shaped probe 30 is detachably mounted and fixed to the probe mounting member 29 by a fixing screw 31.

As shown schematically in FIGS. 1 and 2, the base end portion 27a of the fixed arm 27 is formed in a bifurcated shape so as to sandwich the tip end portion of the main shaft 4 from both sides in the diametrical direction thereof.
By fastening the fastening screw 32 in a state where the tip of the main shaft 4 is sandwiched between the forked portions, the main shaft 4 is fixed to the tip of the main shaft 4.

FIG. 3 is a vertical cross-sectional view showing a connection state between the fixed arm 27 and the swing arm 28. The fixed arm 27 has a U-shaped cross-section free end portion 27b and a U-shaped free end portion 27b. The other end 28 of the swing arm 28 fitted inside
a pair of pivot bearings 33, 33 on both sides
Each pivot bearing 33 is screwed so as to penetrate the ball bearing 33a provided at the other end 28b of the swing arm 28 and the free end 27b of the fixed arm 27, and the tip end thereof is screwed. Ball bearing 33a
And a pivot shaft 33b that is engaged with the center of the shaft so as to be relatively rotatable. Therefore, such a pivot bearing 33
By adopting, the swing arm 28 swings lightly and accurately with respect to the fixed arm 27, and the slide shaft 12 can be operated sensitively and delicately, whereby highly accurate measurement can be performed.

FIG. 5 shows the other end 28 of the swing arm 28.
FIG. 2B is a partially sectional front view showing a state in which b is pivotally attached to the free end portion 27b of the fixed arm 27 having a U-shaped cross section so as to be swingable within a certain angle range, and the swing arm 28 is shown by a solid line in FIGS. In the illustrated state, that is, when one end portion 28a of the swing arm 28 supports the tip of the slide shaft 12 so as to project from the tip of the main shaft 4 by a predetermined length and is biased.
The stopper surface 34 formed on the upper surface of the other end portion 28b of the swing arm 28 serves as a U-shaped free end portion 27 of the fixed arm 27.
2 and 5, the swing arm 28 moves counterclockwise from the position shown by the solid line in FIG. 2 and FIG. 5, that is, against the biasing force of the first spring 13,
Although it can swing in the direction of pushing 2, it cannot swing in the clockwise direction from the position shown by the solid line. Therefore, the swing arm 28 is always held in the position shown by the solid line in FIG. Incidentally, in FIG. 5, a state in which the swing arm 28 is swung in a counterclockwise direction, that is, a direction in which the slide shaft 12 is pushed is shown by an imaginary line.

In FIG. 4, one end 2 of the swing arm 28 is shown.
8A is a longitudinal sectional view showing a state where the tracing stylus attachment member 29 is pivotally attached to the 8a. That is, the tracing stylus attachment member 29 has a pair of both side plate portions 29a and 29b sandwiching the one end portion 28a of the swing arm 28 from both sides thereof.
With one end 28a of the swing arm 28 being sandwiched by 29b, the pivot 36 is passed from one plate 29a side to the one end 28a of the swing arm 28, and the pivot 3
6 has a swing arm 28 and the other plate 29b
A disc spring 37 that is pressed against and is interposed, and a tightening bolt 38 is screwed and fastened from the other plate portion 29b side to the tip end portion of the pivot shaft 36.

Therefore, the tracing stylus attachment member 29 is rotatable with respect to the swing arm 28 about the pivot 36, but cannot be rotated by the disc spring 37 with respect to the swing arm 28 under a certain rotational force. Become. That is, the tracing stylus attachment member 29 can be rotated with respect to the swing arm 28 by applying a rotational force that exceeds the spring force of the disc spring 37 thereto. Therefore, this probe mounting member 29
Can adjust the mounting angle with respect to the swing arm 28 at the same time, and at the same time, can fix it at the adjusted arbitrary angle.

In FIG. 2, 39 is a spacer for holding the bearing 6 in a state of being fitted on the tip of the main shaft 4,
Reference numeral 40 denotes a spring washer which is also interposed between the spacer 39 and the fixed arm 27 in a state where the spacer 39 is externally fitted to the tip end of the main shaft 4 and presses the spacer 39 to the bearing 6 side. The bearing 5 provided on the base end side of the main shaft 4 is
The main shaft 4 is held by a flange portion 4a that is integrally projected. 1 and 2, reference numeral 41 denotes a holder for fixing the spindle 4 side to the spindle S of the machine tool when the centering device is used, and the holder S and the spindle 4 can be attached and detached via an adapter 42. Connected to.
Reference numeral 43 denotes a support P fixed to the table T of the machine tool by a magnetic stand M, and the rotation stop lever 8 is engaged with the support P to prevent the casing 1 from rotating.

In using the dial gauge type centering device having the above-described structure, first, the main spindle 4 is used.
Of the casing 1 is fixed to the holder S via the adapter 42, the holder S is fixed to the spindle S of the machine tool, and the detent lever 8 is locked to the column P on the magnetic stand M to fix the casing 1 to the casing 1. Stop the rotation of.
Then, for example, when performing the centering of the hole H of the work W as shown in FIG. 2, the spindle S of the machine tool is moved to approximately the center position of the hole H of the work W, and the probe for the swing arm 28 is moved. By appropriately adjusting the mounting angle of the mounting member 29, the spherical tip portion 30a of the rod-shaped probe 30 is attached to the hole H.
Contact the inner surface of the. In this way, the rod-shaped probe 30 is brought into contact with the inner peripheral surface of the hole H of the work W, and the fine adjustment knob (not shown) of the dial gauge 9 adjusts until the pointer 19 of the dial gauge 9 starts to move. The spindle S is centered on the workpiece W hole H while rotating at a low speed and appropriately moving the X and Y axes of the machine tool so that the touch of the pointer 19 becomes zero.

In this centering measurement, the rod-shaped probe 30
When the spherical tip portion 30a of is brought into contact with the inner peripheral surface of the hole H,
An external force acts on the rod-shaped probe 30, and the swing arm 2 is in an integral relationship with the rod-shaped probe 30 and the probe mounting member 29.
8 swings upward around the pivot bearing 33 portion which is the swing fulcrum, and pushes up the slide shaft 12 protruding from the tip of the main shaft 4 against the biasing force of the first spring 13. When the slide shaft 12 is pushed up in this way, the horizontal pin 14 supporting the tip of the slide collar 7
This slide collar 7 and the arm receiving pin 24
It moves upwards against the biasing force of the spring 26, and the movement of the arm receiving pin 24 pushes up the support arm 20 and the measurement terminal shaft 17 of the dial gauge 9 moves upward, whereby the pointer 19 swings.

In this case, the gauge body 16 is the casing 1
Since the measurement terminal shaft 17 of the dial gauge 9 moves as the slide shaft 12 moves, the gauge body 16 does not move due to the movement of the measurement terminal shaft 17. Of course, this dial gauge 9
Since the rotation of the casing 1 is blocked by the detent lever 8, the casing 1 is always held at a fixed position in the circumferential direction.

Further, the spindle 4 is rotated by the rotation of the machine tool spindle S, and the spherical tip portion 30 of the rod-shaped probe 30 is rotated.
As a is slid along the inner peripheral surface of the hole H, the external force acting on the rod-shaped probe 30 changes, and the swing arm 28
When oscillates downward about the oscillating fulcrum within its oscillating range, the slide shaft 12 moves downward by the urging force of the first spring 13, that is, moves toward the tip end side of the main shaft 4. When the slide shaft 12 moves downward, the support arm 20 moves downward together with the arm receiving pin 24 by the urging force of the second spring 26, and the slide collar 7 moves downward until its tip comes into contact with the lateral pin 14. . Then, the measurement terminal shaft 17 of the dial gauge 9 is moved downward by the downward movement of the support arm 20, and the pointer 19 is swung. In the centering measurement, the rod-shaped tracing stylus 30 is brought into contact with the inner peripheral surface of the hole H, that is, the measuring surface in an appropriate pressure contact state so that the swing arm 28 always attaches the slide shaft 12 to the first spring 13. Be ready to press against the power.

In the embodiment described above, the slide shaft 12
In addition to the first spring 13 for urging the main shaft 4 toward the tip end side, the support arm 20 protruding from the measuring terminal shaft 17 is urged toward the main shaft 4 tip end side together with the arm receiving pin 24 protruding from the slide collar 7. Although the second spring 26 is provided, the slide shaft 12 and the slide collar 7 are integrally movably connected, and the slide collar 7 and the measurement terminal shaft 17 of the dial gauge 9 are integrally movably connected. Then, the second spring 26 can be omitted.

[0031]

According to the first aspect of the present invention, the rotation of the casing is blocked by the detent lever, and the dial gauge is attached to the casing, and the dial gauge moves as the slide shaft moves. Even if the measuring terminal shaft moves, the display does not move.Therefore, make the measurement in an immovable state while keeping the display part of this gauge stationary at the fixed positions in the circumferential direction of the casing and the measuring terminal axis direction of the gauge. Therefore, the display of the pointer is very easy to see.

According to the second aspect, a horizontal pin is integrally provided on the slide shaft, and the horizontal pin supports the tip of the slide collar. Further, the slide shaft is provided between the slide shaft and the main shaft, and the main shaft tip portion side. Is provided with a first spring that urges in the direction,
On the outer peripheral portion of the slide collar, an arm receiving pin for receiving a supporting arm integrally projecting laterally from the measuring terminal shaft of the dial gauge is integrally projected, and the supporting arm together with the arm receiving pin is directed toward the main shaft tip end side. Since the second spring for urging is provided, the structure in which the slide shaft and the slide collar are integrally movably connected, and the structure in which the slide collar and the measuring terminal shaft of the gauge are interlockingly connected are simplified and manufactured. Will be easier.

According to the third aspect, since the pivot bearing is provided between the free end of the fixed arm and the one end of the swing arm, the swing arm swings lightly and accurately with respect to the fixed arm. As a result, the slide shaft can be moved sensitively and delicately, which enables highly accurate centering measurement.

According to the fourth aspect of the present invention, the mounting member for the tracing stylus can have its mounting angle with respect to the swing arm adjusted at the same time, and at the same time, it can be fixed at the adjusted arbitrary angle. It can be carried out.

[Brief description of drawings]

FIG. 1 is an external front view of a dial gauge type centering device according to the present invention.

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

FIG. 3 is a vertical cross-sectional view showing a connecting portion between a fixed arm and a swing arm.

FIG. 4 is a vertical cross-sectional view showing a connecting portion between a swing arm and a probe mounting member.

FIG. 5 is a partial sectional front view of a connecting portion between a fixed arm and a swing arm.

FIG. 6 is an explanatory view of the dial gauge attached to the casing as seen from the back side.

FIG. 7 is an external perspective view showing a slide collar and an arm receiving pin provided on the slide collar.

[Explanation of symbols] 1 casing 2 Fixed sleeve 4 spindles 7 slide colors 8 Detent lever 9 dial gauge 12 slide axis 13 1st spring 14 horizontal pins 16 gauge body 16a display section 17 Measuring terminal shaft 19 guidelines 20 Support arm 24 Arm receiving pin 26 Second spring 27 Fixed arm 28 swing arms 29 Measuring element mounting member 30 Rod-shaped probe 33 Pivot bearing 36 Axis 37 Disc Spring

Claims (4)

(57) [Claims] 1. A main shaft is rotatably attached to a casing so as to pass through a central portion of the casing, and a detent bar and a dial gauge of the casing are attached to required parts on the peripheral surface side of the casing, and a slide collar is attached to the main shaft. Is fitted so as to be slidable in the axial direction, and this slide collar is interlockingly connected to the measuring terminal shaft provided on the dial gauge, and the slide shaft is fitted so as to be slidable in the axial direction on the tip end side of the main shaft. Then, the slide shaft and the slide collar are connected so as to be integrally movable in the axial direction, and the tip of the slide shaft is biased by a spring so as to project from the tip of the spindle. A fixed arm extending laterally from the main shaft is attached, and the free end of this fixed arm is fixed to the other end of the swing arm whose one end is in contact with the tip of the slide shaft. Swingably pivoted only degree range, the one end side of the measuring element attachment member pivotally connected to the dial gauge type centering device comprising a of the swing arm. 2. The slide shaft is integrally formed with a lateral pin that projects laterally from the slide shaft to support the tip of the slide collar and is movable in the axial direction of the spindle for a predetermined stroke within the spindle. And a first spring for urging the slide shaft toward the main shaft tip end side is provided between the slide shaft and the main shaft.
An arm receiving pin for integrally receiving a supporting arm laterally projecting from the measuring terminal shaft of the dial gauge is integrally projectingly provided, and a second spring for urging the supporting arm together with the arm receiving pin toward a tip end side of the main shaft is provided. The dial gauge type centering device according to claim 1, which is provided. 3. The dial gauge type centering device according to claim 1, wherein a pivot bearing is provided between the free end of the fixed arm and one end of the swing arm. 4. The tracing stylus attachment member is pivotally attached to one end side of the swing arm by a pivot, and a disc spring interposed in the pivot attachment provides a force equal to or less than a predetermined rotational force with respect to the swing arm. The dial gauge type centering device according to claim 1, 2 or 3, which is not rotatable.