JP3238177B2 - Grinding method and cylindrical grinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical grinding machine. In particular, the present invention relates to a cylindrical grinder suitable for processing a workpiece having both grinding portions at both ends.

[0002]

2. Description of the Related Art FIGS. 13 and 14 show a case where end journals Wa and Wb of a workpiece W are machined using a conventional cylindrical grinder. In this example, the workpiece W is a crankshaft. The workpiece W is mounted on a headstock center 11 attached to the workpiece headstock 5 as a workpiece support driving means and a tailstock center 9 attached to the tailstock 6 which does not drive the workpiece W but supports the workpiece. A workpiece rotating jig 12 fixed to a face plate 10 supported and rotatably driven concentrically with a workpiece spindle 13 provided on the workpiece headstock 5 side engages with a crank arm of the workpiece W and the workpiece W
Is rotated to grind with the cylindrical grindstone 3. In the grinding, first, as shown in FIG.
14 and the journal Wb side is supported by the headstock center 11, the journal Wa is ground by the cylindrical grindstone 3, and then the workpiece W is removed and the workpiece W is turned 180 degrees in the axial direction as shown in FIG. The journal Wa side is turned to the headstock center 1
1 and the journal Wb side is supported by the tailstock center 9 to grind the journal Wb. In addition, a grinding wheel, an angular grinding wheel, an angular molding grinding wheel, or the like may be used as the grinding wheel, for example, a cylindrical dish-shaped grinding wheel (the grinding wheel is cylindrical and the function is the same as a cylindrical grinding wheel).

[0003]

In the case of a conventional cylindrical grinder, the grinding of the end of the workpiece is performed by grinding one end as described above, then removing the workpiece and changing the axial direction to the opposite direction. It has to be replaced. Therefore, it takes a lot of time to replace the workpiece, and since the workpiece is replaced, there is a possibility that the accuracy of supporting the workpiece varies and the processing accuracy is reduced. Therefore, there is a method of transmitting a rotational force by inserting a nail driver into a center hole of a workpiece spindle and pressing a nail of the nail driver on an end face of the workpiece, but this method cannot be adopted unless the workpiece has rigidity.

[0004] In particular, it is not used for a workpiece which is easily deformed when both ends are pressed against each other in the axial direction, such as a crankshaft.

An object of the present invention is to provide a grinding machine which can grind both ends of a workpiece without removing the workpiece from the grinding machine with the workpiece mounted.

[0006]

According to a first aspect of the present invention, a workpiece can be supported at both centers facing each other, and a position at which each of the workpieces is engaged with the workpiece to rotate the workpiece is provided. The workpiece is supported at both centers by using a cylindrical grinder in which workpiece supporting and driving means provided with a workpiece rotating jig are provided so as to be retractable so that the workpiece end can be ground. The workpiece rotating jig of the workpiece supporting and driving means is advanced to engage the workpiece so as to rotate the workpiece by rotating the workpiece rotating jig, and the workpiece rotating of the other workpiece supporting and driving means is rotated. The workpiece jig is retracted from the workpiece, the end of the workpiece on which the workpiece rotating jig is retracted is ground, and then the other workpiece supporting drive unit is supported while the workpiece is supported at both centers. Move the workpiece rotation jig forward and machine the workpiece rotation jig to rotate the workpiece And the other end of the workpiece on one side where the workpiece rotation jig of the one workpiece support driving means is retracted from the workpiece and the workpiece rotation jig is retracted. Is a grinding method.

A second invention according to the present invention is directed to a work which comprises a work headstock and a tailstock, each of which has a center hole at both ends and has a center for supporting a work which is supported at the center, and comprises a work headstock and a tailstock facing each other. In a cylindrical grinding machine having two workpiece support driving means provided with a means for supporting the workpiece and a driving means for rotationally driving the workpiece, the two workpiece support driving means have the same configuration, and each of the workpieces has the same configuration. The support driving means is capable of adjusting the position of the workpiece rotation jig support member provided on the body so as to be movable in the axial direction of the workpiece, and the workpiece rotation jig support member in the axial direction. And a fixing means that can fix or release the workpiece rotation jig support member, and can be axially movably fitted to the workpiece rotation jig support member, and the center can be attached to and detached from the tip. Spindle with a large center hole and workpiece A fixing device that can fix or release the workpiece, a driving device that can drive the workpiece spindle in the axial direction, and a workpiece that is rotatably supported at the tip of the workpiece rotation jig support member so as not to move in the axial direction. A workpiece rotation jig for rotating, a face plate provided on the main body side and rotatably supported so as not to move in the axial direction, a driving means provided on the main body for rotating and driving the face plate, A telescopic joint, which connects the jig and the face plate rigidly in the rotational direction and is extendable and contractible in the axial direction of the workpiece main shaft, and advances the workpiece rotating jig support member of one of the workpiece support driving means. The workpiece rotation jig is engaged with the workpiece so that the workpiece is rotationally driven, and the workpiece rotation jig support member of the other workpiece support driving means is retracted to rotate the workpiece. Processing on the side where the jig is retracted from the workpiece and the workpiece rotation jig is retracted Of the workpiece, and then advance the workpiece rotation jig support member of the other workpiece support driving means to engage the workpiece rotation jig with the workpiece so that the workpiece is rotationally driven. At the same time, the workpiece rotation jig support member of one of the workpiece support driving means is retracted to retract the workpiece rotation jig from the workpiece, and the end on the side where the workpiece rotation jig is retracted is removed. A cylindrical grinding machine characterized in that both ends of a workpiece can be ground without removing the workpiece by grinding.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 show sectional side views of a headstock 5 of a workpiece according to an embodiment of the present invention. FIG. 1 shows a front part, and FIG. 2 shows a rear part. Since the tailstock 6 is provided with a work supporting and driving means having the same configuration as the work headstock 5, only the work headstock 5 will be described. In FIG. 1, a sleeve 20 is fitted into a cylindrical hole of a workpiece headstock body 21, and a flange 20 a of the sleeve 20 is provided with a concave portion 21 on a front end surface of the workpiece headstock body 21.
a is fixed by a bolt 20b. Sleeve 20
A quill 1 as a workpiece driving tool support member is fitted in the inner periphery of the workpiece in a freely movable direction in the axial direction. Also, the workpiece spindle 13
The quill 1 is movably fitted in the axial direction. Workpiece W
Is supported by a headstock center 9 (not shown) and a headstock center 11 fitted into a center hole of a workpiece spindle 13 of the workpiece headstock 5 and engaged with a workpiece rotating jig 12. . At the front end of the quill 1, a hollow cylindrical support shaft 15 having a flange 14 on the rear side is fitted and fixed with a spigot 16 of the flange 14. A mounting wheel 18 to which the workpiece rotating jig 12 is rotatably fixed is fixed to the support shaft 15 via a ball bearing 17. The mounting wheel 18 is fixed to a front end of a later-described expansion joint 19, and the expansion joint 19 is fixed. Is fixed to the front side surface of the face plate 10. Collars 22 and 23 and ball bearing 17 are spindle 1
5, and the nut 24 is screwed into the external thread of the support shaft 15, whereby the inner ring of the ball bearing 17, the collars 22, 23
Are fixed to the support shaft 15.

A cover 28 fixed to the rear side of the mounting wheel 18
Fixed the outer ring of the ball bearing 17 and sealed the shaft with the flange 14. A bellows 29 is arranged between the flange 14 of the support shaft 15 and the seal cover 25 fixed to the tip of the sleeve 20.

The pulley 30 is rotatably fixed to the outer periphery of the sleeve 20 via a ball bearing 31 so as not to move in the axial direction. The face plate 10 is fixed to the pulley 30 via a cover 30 a of a ball bearing 31 fixed to the pulley 30.

Work headstock body 2 parallel to sleeve 20
A pulley shaft 3 rotatably fixed to both inner ends of a cylindrical bearing box 33 fitted in the first hole via ball bearings 34, 35.
Pulleys 37 and 38 are fixed to the front and rear end portions of 6.
The pulleys 37 and 30 are at opposing positions, and a V-belt (not shown) is wound around the pulleys. A belt (not shown) is wound between the pulley 38 and a pulley of a work rotation drive motor (not shown) that rotationally drives the work W provided on the work headstock body 21.

As shown in FIG. 2, the workpiece spindle 13 is provided with a screw 39 at the rear end of the small diameter portion.

As shown in FIG. 3 in an enlarged sectional view taken along the line A--A in FIG. 1, a key 41 engaging with a key groove 40 provided in an axial direction at an intermediate portion in the axial direction of the quill 1 is fixed to the sleeve 20. I have. As shown in FIG. 5, the key 8 which engages with a key groove 13a also provided in the axial direction of the
It is fixed to.

As shown in FIG. 4 of the BB enlarged sectional view of FIG. 1, the piston rod 42 of the hydraulic cylinder 32 for fixing the quill 1 slides into the work headstock main body 21 and further moves into the sleeve 2.
0 is inserted, and the quill 1 is pressed down. Similarly, the piston rod 61 of the hydraulic cylinder 57 for fixing the spindle is slid into the sleeve 20 and further inserted through the sleeve 20 to press the workpiece spindle 13 as shown in FIG. It is arranged in.

A gear box 44 is fitted and fixed to a spigot 43 on the rear end surface of the sleeve 20. A thrust bearing 49 is disposed between a flange 47 at the front end of a hollow rotary shaft 46 having a screw 45 to be screwed into a male screw 39 and a flange 48 inside the gear box 44.
A needle bearing 52 and a slide bearing 53 are arranged between a worm gear 51 keyed by a key 50 and a collar 54 and a ball bearing 55 on the rear side of the worm gear 51.
Are respectively fitted to the hollow rotary shafts 46, and the hollow rotary shafts 46
A nut 56 is screwed into a male screw, and the hollow rotary shaft 46 is fixed to the gear box 44 so as to be rotatable and not to move in the axial direction. A worm 58 is orthogonally meshed with the worm gear 51, and is fixed to the gear box 44 so as to be rotatable and not move in the axial direction.

A bearing bracket 44a for accommodating and fixing the outer ring of the ball bearing 55 is fitted into the gear box 44 and fixed with bolts. A lid 44b is fitted into the bearing bracket 44a and fixed with bolts. Stop moving in direction.
The worm 58 is supported so as not to move in the axial direction, and is connected to a motor (not shown).

As shown in FIG. 1, a pinion 7 supported on the workpiece headstock main body 21 meshes with rack teeth provided in the axial direction on the outer periphery of the quill 1, and the pinion 7 is connected to a rotary drive (not shown). ing.

FIG. 6 is a side sectional view of the expansion joint, and FIG.
FIG. 8 is a front view of FIG. The flange 10a of the face plate 10 is a square whose corner is chamfered when viewed from the front, and the end fitting 62 fixed to the front side along each side of the square has three protrusions 63, 64, 65 on the front side. Projections 64, 6
5 is provided with a slider 67 that moves without a backlash along a guide bar 66 fixed in parallel to the square side of the face plate 10 having the projections 64 and 65.

One end of each of a plurality of parallel links 68 and a plurality of parallel links 69 crossing the link 68 is respectively provided by pins 70 and 71 fixed perpendicularly to the outer surfaces of the projection 63 and the slider 67. Pivot. The centers of the pins 70 and 71 are coplanar with the face plate 10, and the links 68 and 69 are pivotally connected to each other at the center by a pin 72, and the other end is connected to one end of each of the other links 69 and 68. 74, 73
To pivot. The distance between the pivot points at both ends of the links 68 and 69 is 2L, and the central pivot point and the pivot points at both ends of the links 68 and 69 each have a distance L.

By repeating the above connection, the last link 68,
The end pivot point of 69 is an end fitting 62 having the same shape as the end fitting 62 described above.
The pin 63 is pivotally attached to the side surface of a projection 63 and a slider 67 attached to the end fitting 62, respectively. The front end pins 70, 71 and the rear end pins 70, 71 of the expansion joint 19
Are parallel, and the lines connecting pins 70, 73 ... 73, 70 and pins 71, 74 ... 74, 71 pivotally connecting the same side end of each link are Even if the sliders 67, 67 move, they are held so as to be parallel to the work main axis.

That is, the expansion joint 19 is rigid in the rotation direction, and can expand and contract in the axial direction of the main shaft 13.

Such a telescopic joint 19 is provided on the workpiece spindle 13.
It is arranged in four places surrounding the front end part.

As shown in FIG. 9, as the expansion joint 19, a hollow spline joint 75 is fixed to the face plate 10, and a spline shaft 76 engaging with the spline joint 75 is attached to the mounting wheel 1.
8 may be fixed. Alternatively, as shown in FIG. 10, a guide park 77 parallel to the workpiece spindle 13 and having one end fixed to the face plate 10 may be slid into a hole 78 provided in the mounting wheel 18.

In the above description, the work headstock 5 and the tailstock 6 each have a spindle fixed position stop device for stopping the face plate 10 at a fixed position.

Next, the operation will be described.

For example, a case in which the workpiece W grinds end journals Wa and Wb at both ends with a crank for an internal combustion engine will be described with reference to FIG.

In the state where the workpiece W has left the machine after the previous machining, the workpiece W has been removed between the centers 9 and 11 of the work headstock 5 and the tailstock 6, and accordingly, any one of them is removed. The workpiece spindle 13 is in the retracted position, and only one of the centers 9 or 11 is immovable, and only the other center is advanced or retracted. The workpiece spindle 13 on the center immovable side is always immovable in the axial direction. Quill 1 is in the most retracted position,
The workpiece rotating jig 12 is retracted to the position shown by the two-dot chain line in FIG. The operation will now be described with the workpiece spindle 13 on the workpiece headstock 5 side immobile.

The workpiece W is moved to both centers 9 by an autoloader or the like.
11 concentrically with the autoloader
Is shifted in the axial direction to the center 11 side of the work headstock, and the center hole of the work W is fitted to the center 11. In response to a signal confirming that the center 11 has been fitted into the center hole, the work spindle feed drive motor on the tailstock side starts rotating, the worm 58 rotates, transmitting the rotation to the worm gear 51 and transmitting the hollow through the key 50 to the hollow. The rotation shaft 46 rotates. When the hollow rotary shaft 46 rotates, the work spindle 13 cannot be rotated by the key 8, so that the work spindle 13 on the tailstock side moves axially toward the work spindle 5 via the screw pair 45 and 39. Then, another center hole of the workpiece W is fitted into the center 9 of the workpiece headstock 5 on the tailstock side.
Backed by, the autoloader leaves.

Regardless of whether the workpiece spindle 13 on the side of the tailstock is in or out, the support shaft 15 (FIGS. 1 and 15) is stationary, and the mounting wheel 18 and the workpiece rotating jig 12 do not move forward.
Next, the pinion 7 on the workpiece headstock side is driven to rotate, and the quill 1 moves forward. The workpiece rotation jig 12 fixed to a mounting wheel 18 rotatably mounted on the support shaft 15 advances with the quill 1 and engages with the crank arm of the workpiece W. At the same time, the expansion joint 19 extends.

The case where the work rest 26 fixed to the collar 22 is used is as follows. When the workpiece W is carried in, the workpiece W is placed on the receiving head 27 of the work rest on the headstock side and the receiving head 27 of the work rest on the tailstock side. By the signal that the autoloader has released the workpiece W, the workpiece spindle feed drive motor is urged in the same direction, the workpiece spindle 13 on the workpiece headstock side advances, and the center 11 enters the center hole of the workpiece W, Subsequently, the workpiece W is pushed toward the tailstock side, and the workpiece W is slid on the work rest receiver 27 to be shifted, and the workpiece W is moved to a fixed axial position by a microswitch or a numerical controller (not shown). To stop. When the position of the workpiece spindle 13 on the workpiece headstock side is determined, the hydraulic cylinder 57 (FIG. 5) on the workpiece headstock side is urged, and the workpiece spindle 13 on the workpiece headstock side is moved by the piston rod 61. It is fixed to the sleeve 20. Next, similarly, the center 9 on the tailstock side advances and fits into the center hole of the workpiece, supports the workpiece W, and fixes the workpiece spindle 13.

In both cases where the autoloader or the like shifts the workpiece W in the axial direction and when the workpiece W is mounted using the work rest 26, the pinion 7 on the workpiece headstock 5 rotates next. Quill 1 moves forward. Quill 1
With the movement of the workpiece W, the workpiece rotating jig 12 moves along with the quill 1, so that the workpiece W is engaged with the crank arm of the workpiece W in the rotation direction. Then, a telescopic joint 19 that is rigid in the rotational direction connecting the face plate 10 and the mounting wheel 18 and that can expand and contract in the axial direction of the workpiece main shaft 13 extends. Then, the hydraulic cylinder 32 for fixing the quill 1 is provided on both the work headstock and the tailstock.
(FIG. 4) is urged forward, and the piston rod 42 advances to fix the quill 1.

Next, a work rotation drive motor (not shown) on the work headstock side rotates, and the pulley 38 shown in FIG. 1 rotates, and the pulley shaft 36 and the pulley 37 rotate through a belt (not shown). The pulley 30 rotates. Cover 30a, face plate 1
0, the workpiece rotating jig 12 rotates the workpiece W via the expansion joint 19 and the mounting wheel 18.

On the other hand, a grindstone base (not shown) rotates the grindstone 3 and approaches the end journal Wb on the tailstock side of the work W, and according to the instruction of the control device (not shown), the work W
Is ground.

When a dish-shaped cylindrical grindstone is used, when the machining of the machining position of the end journal Wb close to the tailstock is completed, the grindstone head moves away from the workpiece W in the radial direction, and a table (not shown) is numerically controlled. To move the workpiece W in the axial direction. On the other hand, the workpiece spindle 13 on the workpiece headstock side
Stops at a fixed position in the rotation direction, and the rotation of the workpiece W stops. Here, the hydraulic cylinder 32 for fixing the quill 1 on the workpiece headstock side is urged in the retreating direction, the piston rod 42 releases the pressing of the quill 1, and the pinion 7 on the workpiece headstock side is reversed. In this direction, the quill 1 is retracted, and the workpiece rotating jig 12 is retracted. At the retracted position, the tip of the jig 12 is further away from the workpiece W in the axial direction than the end of the workpiece W on the one end journal portion Wa side. At the same time, the hydraulic cylinder 32 for fixing the quill 1 on the tailstock side is released, the pinion 7 on the tailstock side rotates and the quill 1 moves forward, and the workpiece rotating jig 12 moves forward to move the end of the workpiece W. Department Journal W
The quill 1 is fixed by engaging with the crank arm on the b side and driving the quill fixing hydraulic cylinder 32 on the tailstock side. Here, the pulley 38 on the tailstock side is rotationally urged to rotate the workpiece rotating jig 12 to give the workpiece W rotation. Next, the grinding wheel 3 is sent to a position where the end journal Wa is machined by the movement of the table, and grinds the end journal Wa of the workpiece W. After the grinding, the tailstock pulley 38 stops, and the workpiece rotating jig 12 stops at the fixed position. Then, the hydraulic cylinder 32 for fixing the quill on the work headstock and the tailstock side and the hydraulic cylinder 57 for fixing the work spindle on the tailstock side are deenergized, and the piston rods 42 and 61 are retracted.

When the autoloader enters and grasps the workpiece W, the spindle feed drive motor on the tailstock side is driven to rotate the worm 58, the workpiece spindle 13 on the tailstock side is retracted, and the center 9 is processed. After moving away from the workpiece W, the autoloader shifts to the tailstock 6 side, and the workpiece W separates from the center 11 of the workpiece W on the workpiece headstock 5 side. Then, the workpiece W is carried out by the autoloader. When the work rest 26 is used, the workpiece W is removed by grasping the workpiece W with an autoloader or the like and then retreating each workpiece spindle 13.

The embodiment is a normal cylindrical grinder using a dish-shaped cylindrical grindstone. As shown in FIGS. 11 and 12, both ends of the same grindstone shaft 80 are provided with angular grindstones 3a and 3b.
The grindstone base 2 provided with the slidably engages with the front and rear slide base 81 having a guide 81a in the direction intersecting with the moving direction of the table 4 on the upper surface so as to be driven by cutting along the slide base 81. Base 81 to bed 82
It may be mounted with a vertical pivot 83 so that it can be rotated. Thus, as shown by the solid line in FIG. 11, the end journal Wa can be ground with the angular grindstone 3a, and the end journal Wb can be ground with the angular grindstone 3b. .

The method of grinding the workpiece W shown in the embodiment is merely an example of operation, and it goes without saying that other working methods are possible according to the configuration of the grinding machine.

In this embodiment, the workpiece spindle on the workpiece headstock and the workstock on the tailstock side can be moved forward and backward. However, either one or both of them can be fixed and the tailstock side and the workpiece headstock side can be used. Either or both of the workpiece headstock bodies can be freely moved in the axial direction on the table, so that the centers 9 and 1 can be moved.
1 may be moved, which also achieves the purpose. In this case, the device for advancing / retreating the work spindle 13 shown in FIG. 2 is unnecessary, and the work spindle 13 is fixed to the main body of the work headstock and tailstock at the rear end.

[0039]

According to the present invention, the workpiece rotating jigs of the two opposing workpiece supporting and driving means can be retracted from the edge of the workpiece, respectively, and the workpiece is moved to the workpiece headstock side and the tailstock side. By enabling the drive of the workpiece from any of
Both ends of the workpiece can be machined without removing the workpiece in the axial direction without inverting, thereby contributing to shortening of machining time and improvement of machining accuracy.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a front portion of an embodiment of the present invention.

FIG. 2 is a side sectional view of a rear portion of the embodiment of the present invention.

FIG. 3 is an enlarged sectional view taken along line AA of FIG.

FIG. 4 is an enlarged sectional view taken along line BB of FIG. 1;

FIG. 5 is a sectional view taken along line CC of FIG. 2;

FIG. 6 is a side sectional view of a telescopic joint according to the embodiment of the present invention.

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a front view of FIG. 6;

FIG. 9 is a longitudinal sectional view of another embodiment.

FIG. 10 is a longitudinal sectional view of another embodiment.

FIG. 11 is a plan view showing an example of application to another grinding machine.

FIG. 12 is a sectional view taken along line DD of FIG. 11;

FIG. 13 is a plan view of a conventional example.

FIG. 14 is a plan view of a conventional example.

FIG. 15 is a partially enlarged view of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Quill 5 Workpiece headstock 6 Tailstock 10 Face plate 12 Workpiece rotation jig 13 Workpiece spindle 18 Mounting wheel 19 Telescopic joint 20 Sleeve

Claims (2)

(57) [Claims] A work piece can be supported at both centers in opposition to each other, and a position where each of the work pieces engages with the work piece to rotationally drive the work piece is retracted from the work piece so that the end of the work piece can be ground. The workpiece is supported at both centers by using a cylindrical grinder in which workpiece supporting and driving means provided with a workpiece rotating jig are arranged opposite to each other, and the workpiece rotating jig of one workpiece supporting and driving means is provided. The workpiece rotating jig is moved forward and engaged with the workpiece so as to rotationally drive the workpiece, and the workpiece rotating jig of the other workpiece supporting / driving means is retracted from the workpiece to rotate the workpiece. Grind the end of the workpiece on the side where the jig has been retracted, then advance the workpiece rotation jig of the other workpiece support drive means while supporting the workpiece at both centers, and rotate the workpiece. The jig is engaged with the workpiece so as to rotate the workpiece, and one of the workpiece support drives is driven. Grinding wherein the grinding the ends of the workpiece the rotary jig is retracted from the workpiece the workpiece rotational jig on one side of the workpiece is retracted and the means. 2. A means for supporting a workpiece, comprising a work headstock and a tailstock, each having a center hole at both ends and having centers for supporting a workpiece supported by the center, each comprising a headstock and a tailstock. In a cylindrical grinding machine having two workpiece support drive means provided with drive means for rotationally driving, the two workpiece support drive means have the same configuration, and each work support drive means has a main body and A workpiece rotation jig support member provided on the main body so as to be movable in the axial direction of the workpiece, and a driving device capable of driving the workpiece rotation jig support member so that the position can be adjusted in the axial direction. A fixing means capable of fixing or releasing the workpiece rotation jig support member; and an axially movably fitted to the workpiece rotation jig support member;
A workpiece spindle having a center hole at the end of which a center can be attached and detached, a fixing device that can fix or release the workpiece spindle, a driving device that can drive the workpiece spindle in the axial direction, and a jig support for workpiece rotation A workpiece rotation jig supported at the tip of the member so as to be rotatable and not moving in the axial direction for rotating the workpiece, and a face plate provided on the main body side and rotatably supported so as not to move in the axial direction. And a driving means provided on the main body and configured to rotationally drive the face plate; The workpiece rotation jig support member of one of the workpiece support driving means is advanced to engage the workpiece rotation jig with the workpiece so that the workpiece is rotationally driven, and to support the other workpiece support jig. Retract the jig support member for workpiece rotation of the drive The workpiece rotation jig is retracted from the workpiece, the end of the workpiece on the side where the workpiece rotation jig is retracted is ground, and then the workpiece rotation jig support of the other workpiece support driving means is provided. The member is moved forward so that the workpiece rotating jig is engaged with the workpiece so that the workpiece is rotationally driven, and the workpiece rotating jig support member of one of the workpiece supporting and driving means is retracted, and the workpiece is rotated. The rotating jig is retracted from the workpiece, and the end on which the workpiece rotating jig is retracted is ground so that both ends of the workpiece can be ground without removing the workpiece. And cylindrical grinder.