JPH10315002A - Machining device of work having noncircular curve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously and concentrically machine inner and outer peripheral surfaces of a work whose inner and outer peripheral surfaces are formed in a noncircular curve by controlling an X shaft driving means and a U shaft driving means in synchronism with rotation of the work by a C shaft driving means. SOLUTION: Left and right spindles are synchronously rotated by a C shaft motor 19 through a C shaft driving means 18 to rotate work 16. A U shaft slide 25a is moved in the U shaft direction by a U shaft motor, and a tool 33 of an inner peripheral surface machining means 25 is moved close to a position where an inside surface of the work 16 is cut from one end side. An X shaft motor 28 is rotated, and a tool support member 24d is advanced in the work 16 direction, and a tool 26 installed on the tool support member 24d is moved close to a position where an outer peripheral surface of the work 16 is cut from one end side. Therefore, cutting work is simultaneously performed on inner and outer peripheral surfaces of the work 16 by the tool 33 of the inner peripheral surface machining means 25 and a tool 26 of an outer peripheral surface machining means 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing a work having a non-circular curve, such as a piston ring, for simultaneously processing the inner and outer peripheral surfaces of a work having a non-circular curve.

[0002]

2. Description of the Related Art Conventionally, a piston ring used in an engine or the like is formed by laminating a large number of non-circular rings, processing the inner and outer peripheral surfaces into a predetermined shape, and then cutting two outer peripheral portions in the axial direction. In general, a method of manufacturing a piston ring in which the outer peripheral surface becomes a perfect circle when the diameter is reduced and the cut portions are brought into close contact with each other has been adopted. Japanese Unexamined Patent Publication No. 54-211691, Japanese Unexamined Patent Publication No. 63-22201, Japanese Patent Publication No. 6-758.
No. 14, for example.

The processing apparatus described in Japanese Patent Application Laid-Open No. Sho 54-21691 is displaced in the radial direction in accordance with the degree of a non-circular curve of a piston ring and a machine shaft on which a stacked piston ring assembly is mounted. Tool support means, and at least two or more electromechanical step drive means controlled by a computer and installed before and after in the direction of its operation. By controlling the step driving means by a computer while rotating the piston ring assembly, the inner and outer peripheral surfaces of a work having a non-circular curve formed by a free curve can be simultaneously and accurately processed.

Japanese Patent Application Laid-Open No. 63-22201 discloses that
A lathe provided with a tool for machining the inner and outer circumferences of a piston ring and moving the tools in the radial direction of the piston ring by a rotating cam so as to simultaneously machine the inner and outer peripheral surfaces of the piston ring is disclosed. .

On the other hand, the numerical control lathe described in Japanese Patent Publication No. 6-75814 has a cutting tool for cutting a work mounted on a carriage that can move forward and backward in a direction of moving the work by a linear motor. A motor is numerically controlled by a computer to cut the outer periphery of a skirt of a work such as a piston.A plurality of sets of rotating members and a biasing device are provided on a guide portion for supporting reciprocation of a carriage. Since the reaction force generated in the tool while the workpiece is being cut is supported by the rotating member and the biasing device, the carriage can be reciprocated without any rattling or shaking, so that the accuracy is high. It has effects such as enabling cutting.

[0006]

However, Japanese Patent Application Laid-Open No. Sho 54-2
In the machining apparatus described in FIG. 1691, in particular, as shown in FIG. 5, a tool in which a tool for machining the outer periphery of a work is mounted on a sliding head that is controlled to move by two step driving means provided side by side. Along with providing the supporting means, on the sliding head, another sliding head that is movable in the same direction as the sliding head by the step driving means is provided,
Because this sliding head is provided with tool support means to which a tool for processing the inner periphery of the work is provided,
Since the driving systems overlap each other and become complicated, and the control means for controlling the driving systems become complicated, there is a problem that the entire apparatus becomes expensive.

The lathe described in JP-A-63-22201 has a structure in which a tool for machining the inner and outer circumferences is mechanically fed using a cam, so that every time the machining shape of the piston ring changes. It is necessary to replace the cams, which requires a lot of time for the replacement work, resulting in poor work efficiency and a need to prepare a plurality of cams having different shapes in advance.
Maintenance and management are troublesome, and there are problems such as increased costs.

Further, since the cam is liable to be rubbed while being used, and the drive system is apt to rattle, it is difficult to perform high-precision machining. There is also a problem that the processing accuracy cannot be corrected.

On the other hand, in the numerical control lathe disclosed in Japanese Patent Publication No. 6-75814, the inner and outer peripheral surfaces of the work cannot be machined at the same time, so that the productivity is poor and when the inner and outer periphery are machined by different machines, Since the concentricity of the inner and outer circumferences is impaired, there is a problem that a piston ring with high processing accuracy cannot be obtained. SUMMARY OF THE INVENTION The present invention has been made in order to improve such a conventional problem, and an object of the present invention is to provide a device for processing a work having a non-circular curve which can simultaneously and precisely process the inner and outer circumferences of the work having the non-circular curve. Is what you do.

[0010]

In order to achieve the above object, a first aspect of the present invention is a processing apparatus for processing the inner and outer peripheral surfaces of a workpiece whose inner and outer peripheral surfaces are formed by non-circular curves having similar shapes. , A Z-axis slide movable in a horizontal (Z-axis) direction by a Z-axis driving means using a servo motor as a drive source, and both ends of a work provided on the Z-axis slide and having a substantially horizontal axis are horizontally moved. U comprising a work supporting means for clamping in a freely rotatable manner, a C-axis driving means having a servo motor for rotating the work in the C-axis direction via the work supporting means, and a linear servo motor.
A U-axis slide that is movable in a U-axis direction orthogonal to the Z-axis by a shaft motor, and a tool attached to the U-axis slide via a boring bar is inserted from an end of the work, An inner surface machining means for machining the inner peripheral surface of the tool, and a tool support member movable in an X-axis direction parallel to the U-axis by an X-axis motor comprising a servomotor, and a tool attached to the tool support member And an outer peripheral processing means for processing the outer peripheral surface of the work.

With the above arrangement, the X-axis driving means and the U-axis driving are controlled in synchronization with the rotation of the work by the C-axis driving means, so that the inner and outer peripheral surfaces of the work are formed by non-circular curves. Can be processed at the same time, greatly improving the productivity compared to the case of processing the inner and outer circumferences in separate steps, and the concentricity of the inner and outer circumferences is not impaired, enabling highly accurate processing. Become.

Further, since each driving means is independent, the structure and control system can be simplified as compared with the conventional processing machine in which the driving means are duplicated, whereby the cost of the entire apparatus can be reduced. Since there is no need to exchange cams according to the work to be performed, it is possible to greatly reduce the setup time due to the change of the work, and it is not necessary to store a plurality of cams, so that maintenance and management become easy.

According to a second aspect of the present invention, there is provided a machining apparatus for machining an inner and outer peripheral surface of a work having an inner and outer peripheral surface formed by a similar non-circular curve, wherein a servo motor is used as a drive source. A Z-axis slide movable in a horizontal (Z-axis) direction by a Z-axis driving means, and a work support provided on the Z-axis slide and clamping both ends of the work having a substantially horizontal axis to be rotatable from the horizontal direction. Means, a C-axis driving means having a servo motor for rotating the work in the C-axis direction via the work supporting means as a driving source, and a U-axis motor comprising a linear servomotor in a U-axis direction orthogonal to the Z-axis. Inner surface machining that has a movable U-axis slide and inserts a tool attached to the U-axis slide via a boring bar from the end side of the work to machine the inner peripheral surface of the work Outer peripheral machining that has a step and a tool support member that is movable in the X-axis direction parallel to the U-axis by an X-axis motor composed of a servomotor, and that processes the outer periphery of the workpiece with a tool attached to the tool support member Means,
It comprises a control means for controlling the Z-axis drive means and controlling the inner peripheral processing means and the outer peripheral processing means in synchronism with the rotation of the work on the C axis.

According to the above configuration, the X-axis drive means and the U-axis drive are controlled in synchronization with the rotation of the work by the C-axis drive means, so that the inner and outer peripheral surfaces of the work are formed by non-circular curves. Can be processed at the same time, greatly improving the productivity compared to the case of processing the inner and outer circumferences in separate steps, and the concentricity of the inner and outer circumferences is not impaired, enabling highly accurate processing. Become.

Further, since each driving means is independent, the structure and the control system can be simplified as compared with the conventional processing machine in which the driving means are duplicated, whereby the cost of the entire apparatus can be reduced. Since there is no need to exchange cams according to the work to be performed, it is possible to greatly reduce the setup time due to the change of the work, and it is not necessary to store a plurality of cams, so that maintenance and management become easy.

Furthermore, compared with the case of mechanically driven by a cam, there is no backlash in the drive system and no friction of the cam. Even if it decreases, it can be easily corrected by the NC device, so that high processing accuracy can be maintained over a long period of time.

According to a third aspect of the present invention, in order to achieve the above object, a piston ring is machined as a work having a non-circular curve.

According to the above configuration, the piston ring can be manufactured with high precision and efficiency.

[0019]

Embodiments of the present invention will be described in detail with reference to the drawings. In the figure, reference numeral 1 denotes a processing apparatus main body, which is constituted by a column 1b having a slide mounting surface 1a which is inclined so that the front side becomes lower. The slide mounting surface 1a is vertically separated from each other and in the horizontal direction (Z axis). Guide rail 2 composed of a pair of linear guides so as to be parallel to
The Z-axis slide 3 is supported on the guide rails 2 so as to be movable in the Z-axis direction.

On the left end surface of the column 1b, a Z-axis motor 4 composed of a servomotor serving as a driving source of a Z-axis driving means 5 is mounted via a gear box 20a of a speed reducer 20 to be described later. As shown in FIG. 4, a screw shaft 5a composed of a ball screw is connected to the rotation shaft 4a of the shaft motor 4, and a nut member 5b fixed to the Z-axis slide 3 is screwed to the screw shaft 5a. The Z-axis slide 4 can be moved in the Z-axis direction along the guide rail 2 by rotating the Z-axis motor 4 forward and reverse with the screw shaft 5a.

The Z-axis slide 3 is provided with a left work support means 10 and a right work support means 11 separated from each other in the left-right direction. Left work support means 10
As shown in FIG. 4, is provided on the right side of the hydraulic cylinder 12 provided on the left side of the Z-axis slide 3, and on the right side of the piston 12a housed in the hydraulic cylinder 12.
It has a left spindle 10a.

The left spindle 10a has a cylindrical shape, and is mounted on the hydraulic cylinder 12 through a plurality of bearings 13 in a Z-shape.
The end face of the piston 12a is attached to the end face of the ring 10b fitted to the outer peripheral portion of the left spindle 10a, while being axially movable and rotatable.
4, the left spindle 10a can be pressurized rightward through the piston 12a by supplying hydraulic pressure to the hydraulic chamber 12b of the hydraulic cylinder 12. At the center of the hydraulic cylinder 12, a fixed shaft 10c having one end fixed to the end surface of the hydraulic cylinder 12 is provided. The other end of the fixed shaft 10c is the piston 1
2a, the center of the left spindle 10a is reached, and a bearing 1d is provided on a spring seat 10d provided at the other end.
A plurality of compression springs 10e are provided to bias the left spindle 10a to the left via the four.

At the end of the left spindle 10a,
A clamp head 10f for clamping the work 16 is provided between the clamp heads 11f provided on the right work support means 11 and a left spindle 10a.
A gear train 18 constituting the C-axis driving means 18
a driven gear 18b is keyed. As shown in FIG. 4, the C-axis drive means 18 has a C-axis motor 19 composed of a servomotor mounted on a gear case 20a of a speed reducer 20 fixed to the left end face of the column 1b.
The shaft motor 19 is connected to the input shaft 20b of the speed reducer 20.

The input shaft 20b has a workpiece 16 at the time of machining.
A flywheel 20c for stabilizing the rotation so that rotation unevenness does not occur is mounted, and an output gear 20d of the speed reducer 20 has a drive shaft 18c composed of a spline shaft.
Of the C-axis motor 1
9 allows the drive shaft 18c to rotate forward and reverse via the speed reducer 20.

The drive shaft 18c is rotatably supported in the horizontal direction so as to be parallel to the axis of the work 16. The drive shaft 18c is provided at the middle and right ends of the left work support means 10 and the right work support means 11, respectively. The drive gear 18d of the gear train 18a is in spline engagement. These drive gears 18d are meshed with driven gears 10b provided on the outer peripheral portion of the left spindle 10a and the outer peripheral portion of the right spindle 11a via the intermediate gear 18e. Through left spindle 1
0a and the right spindle 11a can be synchronously rotated in the same direction.

The right spindle 11a is also formed in a cylindrical shape similarly to the left spindle 10a, and is rotatably supported on the Z-axis slide 3 via a bearing 21. A thrust bearing 22 is interposed between the driven gear 18b keyed to the outer periphery of the spindle 11a. And the right spindle 11a
Further, a clamp head 11f for clamping the work 16 between clamp heads 10f attached to the left spindle 10a is provided.

When the left spindle 10a and the right spindle 11a are rotationally driven synchronously by the C-axis motor 19, rotation unevenness occurs in the left and right spindles 10a and 11a due to splines of the drive shaft 18c and backlash of the gear train 18a. Phase shift occurs. To prevent this, the plate 11g of the right spindle 11a can be fixed by a locking means (not shown) such as Loctite while the backlash of the gear train 18a is removed when the work 16 is processed.

On the other hand, on the column 1b, an inner peripheral machining means 25 for machining the inner peripheral surface of the work 16 is provided.
Outer peripheral processing means 24 for simultaneously processing the outer peripheral surface of the inner peripheral surface with the inner peripheral surface is provided. As shown in FIG. 5, the outer peripheral processing means 24 has a support member 24a fixed to the rear surface of the column 1b, and a cylindrical guide member 24b is parallel to the X axis at the end of the support member 24a. The guide member 24b has a ball spline 24c.
The tool support member 24d is supported movably in the X-axis direction via.

A tool 26 for cutting the outer peripheral surface of the work 16 is detachably attached to an end of the tool support member 24c on the work 16 side via a tool attachment member 24e. On the opposite end,
The nut member 27a is fixed, and this nut member 2
One end of a screw shaft 27 composed of a ball screw is screwed into 7a. An X-axis motor 28 composed of a servomotor is connected to the other end of the screw shaft 27. By rotating the X-axis motor 28 in the normal or reverse direction, the tool support member 24d on which the tool 26 is mounted is moved to the workpiece. 16 can be moved in the direction of contact and separation.

As shown in FIG. 6, the inner peripheral processing means 25 for processing the inner peripheral surface of the work 16 is a roller type linear machine laid in the U-axis direction parallel to the X-axis on the vertical surface 1c of the column 1b. It has a U-axis slide 25a supported on a guide rail 31 composed of a guide. The upper part of the U-axis slide 25a is covered with a roof-shaped cover 25c so that chips are easily discharged, and the U-axis slide 2
A U-axis slide 25 is provided between the vertical surface of the column 5a and the column 1b.
U consisting of a linear servomotor that drives a in the U-axis direction
A shaft motor 32 is provided.

The distal end of the U-axis slide 25a reaches the right side of the right spindle 11a, and the lower end of a substantially horizontal boring bar 25b is fixed to the distal end. The tip side of the boring bar 25b reaches the inside of the work 16 through the right spindle 11a, and a tool 33 for cutting the inner periphery of the work 16 is detachably attached to the tip end.

In FIG. 6, reference numeral 34 denotes a slide position detecting means such as a linear scale for detecting the position of the U-axis slide 25a. The signal detected by the detecting means 34 is the Z-axis motor 4, the C-axis motor 19, the U-axis The data is input to an NC device 35 that performs NC control of the motor 32 and the like.

In FIG. 1, reference numeral 36 denotes a chip conveyor, which carries chips such as chips generated when processing the work 16 to a chip box 37 installed near the processing machine body 1.

Next, the operation of the above-structured processing apparatus will be described. The work 16 that can be processed by this processing device is
With a piston ring or the like having the same shape of the inner and outer peripheral surfaces and different only in the diameter, it is possible to efficiently process a relatively large processing diameter.

Further, since the work 16 is rotated by the C-axis motor 19 and the inner and outer circumferences of the work 16 are simultaneously processed,
The X-axis motors 29 and U are synchronized with the rotation of the C-axis motor 10.
NC motor 35 and Z-axis motor 4
It is necessary to control, and in a normal processing cycle, processing of movement data takes time, and processing is difficult. Therefore, in this embodiment, the machining is performed by selecting the high-speed cycle machining of the NC device 35 or the DNC operation.

When machining is performed by the high-speed cycle machining of the NC unit 35, data converted into the amount of movement per basic processing time and the number of repetitions of the cycle are registered in the high-speed machining data area and the header part of the NC unit 35. Then, high-speed cycle machining is performed by the machining main program. In the processing, a cylindrical work 16 is formed by laminating a plurality of piston rings with the same phase, and is clamped from the left and right directions by a hand carrier jig (not shown). Carry in 1
It is set between the clamp heads 10f, 11f of the left spindle 10a and the right spindle 11a.

In this state, the hydraulic pressure is supplied to the hydraulic chamber 12b of the hydraulic cylinder 12, and the left spindle 10a is moved rightward together with the piston 12a.
The workpiece 16 is clamped between the clamp head 10f of the right spindle 11a and the clamp head 11f of the right spindle 11a so that the center line of the work 16 coincides with the centers of the left and right spindles 10a, 11a.

Next, when the phase of the work 16 is indexed in this state, the right and left spindles 10a and 11a are synchronously rotated by the C-axis motor 19 via the C-axis driving means 18 to rotate the work 16 and the U-axis. U by motor 32
By moving the shaft slide 25a in the U-axis direction, the tool 33 of the inner peripheral processing means 25 is approached to a position where the inner surface of the work 16 is cut from one end side. At this time, the outer peripheral processing means 2
4 is retracted to a position where it does not interfere with the right work support means 11,
Immediately before cutting the inner peripheral surface of the work 16, the X-axis motor 2
8, the tool support member 24e is advanced in the direction of the work 16, and the tool 2 attached to the tool support member 24e is rotated.
6 is approached to a position where the outer peripheral surface of the work 16 is cut from one end side, and the tool 33 of the inner peripheral surface machining means 25 is
The inner and outer peripheral surfaces of the work 16 are simultaneously cut by the tool 26 of the outer peripheral surface processing means 24.

Further, since the inner and outer peripheral surfaces of the work 16 are formed by different free curves, the X-axis motor 29 and the U-axis motor 32 are separately NC-controlled in synchronization with the rotation of the C-axis so that the inside and outside of the work 16 can be controlled. Along with processing the peripheral surface, the Z-axis motor 4 moves the Z-axis slide 3 in the Z-axis direction as the processing proceeds, thereby cutting the inner and outer circumferences over the entire length of the work 16. Chips generated during processing fall onto the chip conveyor 35 and are carried out to the chip box 36 by the chip conveyor 35.

When the machining of the work 16 is completed as described above, the tool support member 24e is retracted by the X-axis motor 28, and the tool 26 of the outer peripheral machining means 24 is retracted to the retracted position. After the U-axis slide 25a is retracted to the original position by the operator and the Z-axis slide 2 is raised to the original position by the Z-axis motor 4, the hydraulic cylinder 12
The hydraulic pressure in the hydraulic chamber 12b is discharged, the left spindle 10a is raised by the action of the compression spring 10e, and the work 16 is unclamped. Thereafter, the work 16 is clamped from the left and right directions by the hand carrier jig so that the phases of the piston rings do not shift, and the clamp heads 10f, 11f are clamped.
The work 16 is carried out from between
When processing No. 6, the above operation may be repeated.

In the above embodiment, the outer peripheral processing means 2
The fourth tool 26 is moved forward and backward by the X-axis motor 28, but may be moved forward and backward using an actuator such as a servo cylinder. In addition, although the case of the piston ring in which the workpieces to be processed are stacked has been described, the present invention is not limited to the piston ring, but can be applied to all types of workpieces such as cams and pistons whose inner and outer circumferences have similar non-circular curves.

[Brief description of the drawings]

FIG. 1 is a front view of a processing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of the processing apparatus according to the embodiment of the present invention.

FIG. 3 is a side view of the processing apparatus according to the embodiment of the present invention;

FIG. 4 is a sectional view of a C-axis and a Z-axis drive unit of the processing apparatus according to the embodiment of the present invention;

FIG. 5 is a sectional view of an outer peripheral processing means of the processing apparatus according to the embodiment of the present invention;

FIG. 6 is a partially cutaway side view of an inner peripheral processing means of the processing apparatus according to the embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Processing machine main body 1a ... Mounting surface 1b ... Column 1c ... Vertical surface 2 ... Guide rail 3 ... Z-axis slide 4 ... Z-axis motor 4a ... Rotating shaft 5 ... Z-axis drive means 5a ... Screw shaft 5b ... Nut member 10 ... Left work support means 10a ... Left spindle 10b ... Ring 10c ... Fixed shaft 10d ... Spring seat 10e ... Compression spring 11 ... Right work support means 11a ... Right spindle 11b ... Ring 11c ... Fixed shaft 11d ... Spring seat 11e ... Compression spring 11f ... Clamp head 11g Plate 12 Hydraulic cylinder 12a Piston 12b Hydraulic chamber 14 Bearing 16 Work 18 C-axis drive means 18a Gear train 18b Drive gear 18c Drive shaft 18d Drive gear 18e Intermediate gear 19 C-axis motor 20: reducer 20a: gear case 21: bearing 22: thrust bearing 24 ... outer peripheral processing means 24a ... support member 24b ... guide member 24c ... ball spline 24d ... tool support member 24e ... tool mounting member 25 ... inner peripheral processing means 25a ... U-axis slide 25b ... boring bar 25c ... cover 26 ... tool 27 ... Screw shaft 27a Nut member 28 X-axis motor 31 Guide rail 32 U-axis motor 33 Tool 34 Detection means 35 NC unit 36 Chip conveyor 37 Chip box

Claims (3)

[Claims] 1. In a processing apparatus for processing the inner and outer peripheral surfaces of a work 16 whose inner and outer peripheral surfaces are formed by non-circular curves having similar shapes, horizontal (Z-axis) is performed by Z-axis driving means 5 using a servo motor as a driving source. Z-axis slide 3 that is movable in the direction, work support means 10 and 11 that are provided on the Z-axis slide 3 and that clamp both ends of a work 16 whose axis is substantially horizontal so as to be rotatable from the horizontal direction. Work support means 1
The C-axis drive means 18 is driven by a servo motor for rotating the work 16 in the C-axis direction via 0 and 11, and is moved in the U-axis direction orthogonal to the Z-axis by a U-axis motor 32 composed of a linear servomotor. A free U-axis slide 25a is provided, and a boring bar 25 is attached to the U-axis slide 25a.
b, a tool 33 attached through the end of the work 16 is inserted from the end of the work 16, and an inner surface processing means 25 for processing the inner peripheral surface of the work 16 and an X-axis motor 28 composed of a servomotor are used to be parallel to the U-axis. A tool support member 24d movable in the X-axis direction, and a peripheral processing means 24 for processing the outer peripheral surface of the work 16 by a tool 26 attached to the tool support member 24d. Processing equipment for workpieces with non-circular curves. 2. In a processing apparatus for processing an inner and outer peripheral surface of a work 16 whose inner and outer peripheral surfaces are formed by non-circular curves having similar shapes, horizontal (Z-axis) is performed by Z-axis driving means 5 using a servo motor as a drive source. Z-axis slide 3 that is movable in the direction, work support means 10 and 11 that are provided on the Z-axis slide 3 and that clamp both ends of a work 16 whose axis is substantially horizontal so as to be rotatable from the horizontal direction. Work support means 1
The C-axis drive means 18 is driven by a servo motor for rotating the work 16 in the C-axis direction via 0 and 11, and is moved in the U-axis direction orthogonal to the Z-axis by a U-axis motor 32 composed of a linear servomotor. A free U-axis slide 25a is provided, and a boring bar 25 is attached to the U-axis slide 25a.
b, a tool 33 attached through the end of the work 16 is inserted from the end of the work 16, and an inner surface processing means 25 for processing the inner peripheral surface of the work 16 and an X-axis motor 28 composed of a servomotor are used to be parallel to the U-axis. A tool supporting member 24d movable in the X-axis direction to control the outer peripheral machining means 24 for machining the outer periphery of the work 16 with a tool 26 attached to the tool supporting member 24d; And a control means for controlling the inner peripheral processing means 25 and the outer peripheral processing means 24 in synchronization with the rotation of the workpiece 16 along the C-axis. 3. The apparatus for processing a workpiece having a non-circular curve according to claim 1, wherein a piston ring is processed as the workpiece having a non-circular curve.