JP2019072800A - Work-piece centering device, processing device provided with the same and work-piece centering method - Google Patents

Abstract

To provide a work-piece centering device capable of performing centering of a work-piece in a short time with a simple constitution.SOLUTION: A work-piece centering device 10 which performs centering of a work-piece W having a circumferential surface Wa retained by a magnet chuck 53 provided on a spindle 52 of a processing device 50 is provided with a plurality of centering tools 12 arranged at an interval in a circumferential direction around a standard axial center C1 arranged concentric with the spindle 52 and a driving part 11 which moves the plurality of centering tools 12 respectively from the standard axial center C1 to prescribed centering positions which are equidistant from each other in a radial direction and brings the respective centering tools 12 into contact with the circumferential surface Wa of the work-piece W retained by the magnetic chuck 53.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a work centering device, a processing device provided with the same, and a work centering method.

  For example, the outer ring and the inner ring of the rolling bearing are subjected to surface finishing in the manufacturing process in order to increase the dimensional accuracy of the inner peripheral surface and the outer peripheral surface. Grinding is generally performed as surface finishing, but recently, with the improvement of the performance of cutting tools such as CBN tools, hard turning may be performed to cut a fired work with high accuracy. In either case, in order to achieve a highly accurate surface finish, a "centering operation" is performed in which the axial center of the spindle for rotating the workpiece and the axial center of the workpiece are exactly aligned.

  Patent Document 1 below discloses a technique for centering a work held by a magnet chuck provided on a main shaft. In this technology, an annular workpiece is attracted to a weakly excited magnet chuck, and while rotating the workpiece by the main shaft, two drive units are moved in the radial direction toward the outer peripheral surface of the workpiece, and the tips of both drive units The position of the workpiece is adjusted by contacting the outer peripheral surface of the workpiece. At the same time, the position of the work is confirmed by the measuring instrument, and when the work center axis is within the value of the predetermined alignment range, the work centering work is finished.

JP 10-43985 A

  In the technique of Patent Document 1, while the position of the workpiece is adjusted by the two drive units while measuring the position of the workpiece by the measuring device, it takes time for the centering operation. In addition, a measuring instrument and a mechanism for moving the measuring instrument are required, and the structure of the work centering device becomes complicated.

  An object of the present invention is to provide a work centering apparatus and a work centering method capable of centering a work with a simple configuration in a short time.

(1) The present invention is a work centering apparatus for centering a work having a circumferential surface held by a magnet chuck provided on a spindle of a processing apparatus, wherein a reference axis is disposed concentrically with the spindle The plurality of centering devices disposed at intervals in the circumferential direction and the plurality of centering devices are respectively moved in the radial direction to predetermined centering positions equidistant from each other from the reference axis. And a drive unit for bringing the centering tools into contact with the circumferential surface of the work held by the magnet chuck.
In the above configuration, the “circumferential surface” refers to, for example, a circular inner peripheral surface or an outer peripheral surface of a work formed in an annular, cylindrical, disc, or cylindrical shape.

  According to the work centering device of the above configuration, the work center axis is made to coincide with the work center axis by moving the plurality of centering tools radially to the work centering position equidistant from the reference work center. As a result, the centering operation can be performed in a short time and with a simple configuration without using a measuring instrument.

(2) Preferably, the plurality of centering devices are arranged at positions equidistantly in the radial direction from the reference axis, and the driving unit is configured to simultaneously rotate the plurality of centering devices in the same stroke. Move to
With such a configuration, the work of centering the work can be performed in a shorter time as compared with the case where the centering tools are moved in the radial direction at different timings.

(3) Preferably, the drive unit is an air cylinder.
With such a configuration, the present invention can be suitably applied to a processing apparatus originally equipped with an air supply device, such as a machining center or an NC lathe.

(4) Preferably, the centering devices are provided at three locations spaced apart around the reference axis.
With such a configuration, the centering device contacts the circumferential surface of the work at three points, so centering work can be performed in a short time and with high accuracy using as few centering devices as possible. be able to.

  (5) The processing apparatus according to the present invention includes a main spindle, a magnet chuck for holding a work provided on the main spindle and having a circumferential surface, and the work centering according to any one of the above (1) to (5) And an apparatus.

  (6) The present invention is a work centering method using the work centering device according to any one of the above (1) to (5), wherein the magnet chuck provided on the main shaft of the processing device is weakly excited. Holding a workpiece having a circumferential surface with the magnet chuck, rotating the spindle, and arranging a plurality of alignment tools in a state in which the reference axis of the workpiece centering device is disposed concentrically with the spindle Moving the centering tool to a centering position equidistant from each other from the reference axis, and bringing the centering tool into contact with the circumferential surface of the workpiece.

  According to this work centering method, the position of the work can be adjusted for centering by holding the work with the magnet chuck in a weakly excited state. Further, by rotating the main shaft to rotate the work, the plurality of centering tools can be brought into contact with the entire circumferential surface of the work to perform centering with high accuracy. Then, by moving the plurality of centering tools to predetermined centering positions equidistant from each other from the reference axis, it is possible to center the work without using a measuring instrument.

  According to the present invention, centering of a work can be accurately performed in a short time.

It is a front view of the workpiece centering device concerning a 1st embodiment. It is a side view (partly, sectional drawing corresponded to the AA of FIG. 1) of a workpiece | work centering apparatus. It is a perspective view of a drive part. It is a perspective view of a centering device. It is a side view equivalent to Drawing 2 of work centering device concerning a 2nd embodiment.

Hereinafter, embodiments of the present invention will be described based on the drawings.
First Embodiment
FIG. 1 is a front view of a workpiece centering device according to a first embodiment. FIG. 2 is a side view (partly, a cross-sectional view corresponding to the line AA of FIG. 1) of the workpiece centering device.
The workpiece centering device 10 according to the first embodiment is applied to a processing device 50 that performs, for example, hard turning to cut the surface of the workpiece W using a high hardness cutting tool, and the tool main spindle 51 of the processing device 50. It is attached to and used. As this processing apparatus 50, a machining center, an NC lathe, etc. can be mentioned, for example. The processing device 50 has a main shaft 52 for rotating the workpiece W, and a tool main shaft 51 which can be disposed concentrically with the main shaft 52. The main chuck 52 is provided with a magnet chuck 53 for holding the work W.

  The work W according to the present embodiment is formed in an annular shape like, for example, an outer ring or an inner ring of a rolling bearing, and has a circumferential surface including an inner circumferential surface Wa and an outer circumferential surface Wb. In the present embodiment, the outer ring of the tapered roller bearing is illustrated as the work W, and the outer ring has a conical inner circumferential surface Wa and a cylindrical outer circumferential surface Wb.

The work centering device 10 has a drive unit 11 and a centering tool 12.
The drive part 11 of this embodiment is comprised by the air cylinder. Therefore, in the following description, the air cylinder is also given the same reference numeral 11 as the drive unit. The air cylinder 11 has a cylindrical cylinder body 21 and a plurality of movable parts 22 provided on one axial end face of the cylinder body 21 as shown in FIG. 3.

  As shown in FIGS. 1 and 3, the movable portions 22 of the air cylinder 11 are disposed at equal intervals in the circumferential direction around the axial center (center) C1 of the cylinder body 21. In the present embodiment, three movable portions 22 are arranged at equal intervals around the axis C1 at an angle of 120 °. Further, the plurality of movable portions 22 have the same distance from the axial center C1, and are configured to move in the radial direction simultaneously with the same stroke by the operation of the air cylinder 11.

  As shown in FIG. 2, the workpiece centering device 10 also includes an adapter 13 mounted on the other end surface of the cylinder body 21 in the axial direction. The adapter 13 has a disc portion 13a fixed to the other end surface of the cylinder body 21 by a screw or the like, and a shaft portion 13b extending substantially perpendicularly from the center of the disc portion 13a. The work centering device 10 also includes a tool holder 14 mounted on the shaft portion 13 b of the adapter 13. For example, a so-called hydro chuck is employed as the tool holder 14. The tool holder 14 has an insertion hole 14a into which the shaft portion 13b of the adapter 13 is inserted, and has a function of hydraulically gripping the shaft portion 13b of the adapter 13 inserted into the insertion hole 14a.

  The tool holder 14 of the workpiece centering device 10 is detachably mounted on the tool spindle 51 of the processing device 50. When the processing device 50 is a machining center, the workpiece centering device 10 is accommodated in the tool magazine, and when performing the centering operation, the workpiece centering device 10 is taken out of the tool magazine by an automatic tool changer (ATC) and the tool holder 14 is mounted on the tool spindle 51. When the processing device 50 is an NC lathe, the work centering device 10 is attached to the collet, and the work centering device 10 is moved to a predetermined position when performing the centering operation. Therefore, the work centering device 10 is accommodated in a tool storage unit such as a tool magazine or a collet, and when performing centering work, the work carrier is transported to the use position of the tool by the tool transport unit and used for centering work. You

  The tool spindle 51 is disposed concentrically with the axis O 2 of the spindle 52 of the processing device 50 when performing the centering operation. The air cylinder 11 of the work centering device 10 is mounted on the tool spindle 51 in a state where the axis C1 of the cylinder body 21 matches the axis O1 of the tool spindle 51. Therefore, when the centering operation is performed, the main shaft 52, the tool main shaft 51, and the work centering device 10 (air cylinder 11) are all arranged concentrically. In the present specification, the axial center C1 of the workpiece centering device 10 is also referred to as “reference axial center C1” which is a reference of the position of each alignment tool 12.

  The tool main spindle 51 of the processing device 50 is a through spindle type, and an air passage 51a is formed in the axial center O1 along the axial direction. The processing device 50 includes an air supply device (not shown) such as an air motor, and can discharge air from the air passage 51 a of the tool main shaft 51. The air cylinder 11 operates by supplying air from the air passage 51 a of the tool main shaft 51 to the axial end face through the air passages 14 c and 13 c formed in the tool holder 14 and the adapter 13. Therefore, the air cylinder 11 operates with the air supply device originally provided in the processing device 50 as a drive source.

  As the air cylinder 11, for example, those known by Japanese Patent Application Laid-Open Nos. 2005-219136 and 2004-9151 can be used. More specifically, MHS 3-673C-X84 (parallel opening / closing air chuck / 3 claw type) manufactured by SMC Corporation can be used. In the air cylinder 11 of the present embodiment, the movable portion 22 moves radially outward by the supply of air, and when the supply of air is stopped, the movable portion 22 returns to the radially inner side. However, the air cylinder 11 is not limited to the one illustrated above, and one having a similar function can be applied.

  As shown in FIG. 1 and FIG. 2, the centering tool 12 is attached to each movable portion 22 of the air cylinder 11. As shown in FIG. 4, the centering tool 12 includes a main body portion 30 having a first plate portion 31 and a second plate portion 32 and bent in a substantially L shape, and a second plate portion 32 of the main body portion 30. And a contact member 33 attached thereto. A plurality of insertion holes 31 a are formed in the first plate portion 31 of the main body portion 30. Further, as shown in FIG. 3, a plurality of female screw holes 22 a are formed in the movable portion 22 of the air cylinder 11. Then, the centering device 12 is fixed to the movable portion 22 by screwing the fixing screw 34 inserted into the insertion hole 31a into the female screw hole 22a.

  The contact member 33 has a cylindrical casing 35 and a contact 36 provided at the tip of the casing 35. The casing 35 has an external thread on the outer peripheral surface, and is screwed into an internal thread hole 32 a formed in the second plate portion 32 of the main body 30. In addition, the casing 35 is locked by a nut 37 screwed to the outer peripheral surface. The contact 36 is formed of a ceramic ball, is rotatably supported at the tip of the casing 35, and a portion thereof protrudes from the casing 35. The centering device 12 is attached to the air cylinder 11 with the contacts 36 directed outward in the radial direction of the air cylinder 11.

  The magnet chuck 53 of the processing device 50 is formed in a disk shape, and is connected to the tip of the main shaft 52 of the processing device 50. The center of the magnetic chuck 53 coincides with the axial center O 2 of the main shaft 52. Therefore, the magnet chuck 53 rotates with the main shaft 52 about the axis O 2 of the main shaft 52, that is, around its own center. One side surface of the magnet chuck 53 is an adsorption surface 53 a for adsorbing the magnetic material.

  The magnet chuck 53 is configured of an electromagnet that generates a magnetic force by flowing an electric current. Therefore, the magnetic chuck 53 can change the magnitude of the magnetic force by changing the magnitude of the current. The magnet chuck 53 of the present embodiment is configured to weaken the holding force of the work W by making the magnetic force at the time of centering work smaller (weaker excitation) than the magnetic force at the time of processing. .

(Procedure of centering work)
Hereinafter, the procedure of the centering operation will be described.
First, the workpiece W is attracted to the magnet chuck 53 of the processing device 50 in a weakly excited state. Further, the work centering device 10 is mounted on the tool spindle 51 of the processing device 50.
Then, the tool spindle 51 is moved along the axial center O 1, and the centering tool 12 of the workpiece centering device 10 is disposed radially inward of the workpiece W held by the magnet chuck 53.

  Then, while rotating the work W by rotationally driving the main shaft 52, the air cylinder 11 is operated to move each centering tool 12 radially outward, and the contacts 36 at the radially outer end are contained in the work W Contact the circumferential surface Wa. The rotational speed of the work W is, for example, 50 to 100 rpm. Further, the contact time of the contact 36 is several seconds to several tens of seconds.

  When the work W is held by the magnet chuck 53 in a state of being eccentric to the axial center O2 of the main shaft 52, any one of the centering tools 12 contacts the inner circumferential surface Wa of the work W, and the centering tools The position of the work W is adjusted while the work W is attracted to the magnet chuck 53 by moving the work 12 radially outward as it is, and all the centering tools 12 contact the inner circumferential surface Wa of the work W. The position is determined in a predetermined manner, and is accurately centered.

  The movement of each centering tool 12 in the radial direction is restricted at a predetermined position by bringing all the centering tools 12 into contact with the inner circumferential surface Wa of the work W, and as a result, the corresponding position is determined by each centering tool 12 It becomes a "centering position" for centering the work W. The centering positions of the centering devices 12 are equidistant from the reference axis C1. Therefore, in other words, the work W can be centered by moving the centering tools 12 to predetermined centering positions equidistant from the reference axis C1.

In the work centering apparatus 10 according to the present embodiment, the plurality of centering tools 12 are simultaneously moved in the same stroke to be in contact with the inner peripheral surface Wa of the work W. It can be carried out.
Further, in the work centering apparatus 10 of the present embodiment, when performing the centering operation, the magnet chuck 53 is in a weakly excited state, so that the work W can be easily moved by the contact with the centering tool 12. Position adjustment can be easily performed without distorting W.

Further, since the work centering device 10 of the present embodiment rotates the work W when performing the centering operation, each centering tool 12 can be brought into contact with the entire inner circumferential surface Wa of the work W, The accuracy of centering can be further improved.
It is possible to apply what is marketed as the air cylinder 11 and the contact member 33 as the workpiece centering apparatus 10 of this embodiment, and can be manufactured as inexpensively as possible.

  Since the rotatable contact 36 is provided at the tip of the centering device 12, the resistance due to the contact with the work W can be reduced, and the rotation of the work W is not hindered. Further, since the contact 36 is made of ceramic, it is lighter than the contact made of metal, can be easily rotated by the contact with the work W, and the resistance can be further reduced.

Second Embodiment
FIG. 5 is a partial sectional view corresponding to FIG. 2 of the work centering apparatus 10 according to the second embodiment.
The workpiece centering device 10 according to the present embodiment performs centering when the centering tool 12 contacts the outer peripheral surface Wb of the workpiece W. The drive unit 11 of the work centering apparatus 10 is substantially the same as that of the first embodiment, and is configured by an air cylinder. However, the air cylinder 11 of this embodiment is configured such that the movable portion 22 moves radially inward by the supply of air, and when the supply of air is stopped, the movable portion 22 returns radially outward.

The centering device 12 includes a main body portion 30 in which the first plate portion 31 is formed radially longer than the centering device 12 of the first embodiment, and the second plate portion 32 of the main body portion 30 contacts The contact member 33 is attached with the teeth 36 directed radially inward.
In the present embodiment, with the plurality of centering tools 12 moved radially outward, the work centering device 10 is brought close to the work W along the axial center O1, and the centering tools 12 are radially outside the work W. Position on Then, by moving the centering tool 12 radially inward to bring the contact 36 into contact with the outer peripheral surface Wb of the workpiece W, it is possible to adjust the position of the workpiece W and perform centering.

The present invention is not limited to the above embodiment, but can be modified within the scope of the invention described in the claims.
For example, the drive unit 11 of the work centering device 10 may be provided individually for each of the plurality of centering tools 12 or may be moved individually at different timings. .

The number of centering devices 12 is not limited to three, and may be two or four or more. However, by setting the number to three, the centering of the work W can be accurately performed in a short time and with the centering tool 12 as few as possible.
The air cylinder as the drive unit 11 is not limited to the single-acting type but may be a double-acting type.

  Although the annular work W is illustrated like the inner ring or the outer ring of the rolling bearing in the above embodiment, the present invention is not limited to this, as long as it is a work W having at least a circular inner or outer peripheral surface. For example, it may be a workpiece W having a circular inner circumferential surface and a polygonal outer circumferential surface, or a workpiece opposite to that.

Although the workpiece centering device 10 is mounted on the tool spindle 51 of the processing device 50 in the above embodiment, the present invention is not limited to this, and the workpiece centering device 10 may be mounted on another shaft arranged concentrically with the spindle 52. For example, the work centering device 10 can be used by being attached to a coring stand in a lathe.
Further, the processing device 50 to which the present invention is applied is not limited to the cutting device, and may be another device such as a grinding device.

10: work centering device, 11: air cylinder (drive unit), 12: centering tool, 36: contactor, 50: processing device, 52: main shaft, 53: magnetic chuck, W: work, Wa: inner circumferential surface , Wb: outer surface

Claims (6)

A work centering apparatus for centering a work having a circumferential surface held by a magnet chuck provided on a spindle of a processing apparatus, comprising:
A plurality of centering devices circumferentially spaced about a reference axis concentric with the main axis;
The plurality of centering tools are radially moved to predetermined centering positions equidistant from each other from the reference axis, and each centering tool is placed on the circumferential surface of the work held by the magnet chuck. A workpiece centering device, comprising: a drive unit to be brought into contact with the workpiece; The plurality of centering devices are arranged at positions equidistantly in the radial direction from the reference axis,
The work centering apparatus according to claim 1, wherein the drive unit moves the plurality of centering tools simultaneously in the same stroke in the same stroke.   The workpiece centering device according to claim 1, wherein the drive unit is an air cylinder.   The workpiece centering device according to any one of claims 1 to 3, wherein the centering device is provided at three locations spaced apart around the reference axis. With the spindle
A magnet chuck for holding a workpiece provided on the main shaft and having a circumferential surface;
A processing apparatus comprising the work centering device according to any one of claims 1 to 4. A work centering method using the work centering device according to any one of claims 1 to 4,
Holding a workpiece having a circumferential surface by the magnet chuck with the magnet chuck provided on the main shaft of the processing apparatus in a weakly excited state;
Rotationally driving the spindle
A plurality of centering tools are respectively moved to centering positions equidistant from each other from the reference axis in a state where the reference axis of the work centering device is disposed concentrically with the main axis, and the circumferential surface of the work is And D. bringing the centering device into contact with the workpiece.

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