JPH1058202A - Nc machine tool having sphere machining device and sphere machining method used in the machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically perform a process from rough machining to a spherical finish by applying the constitution that a machine tool used for boring or rough machining bore internal surface is provided with a sphere machining device for finishing a workpiece to a sphere as integral part thereof. SOLUTION: Bore internal surface is rough machined with a tool T under the axial motion of a column 48 and a tool rest 47 along an Z-axis and a X- axis. Then, the column 48 and the tool rest 47 are axially moved along a Z-axis and the X-axis, thereby being made to retreat from a workpiece W. Also, a sphere machining device 1 is axially moved in the Z-axis direction along a horizontal guide 46, thereby inserting a cutter 16 in the bore of the workpiece W. Then, the workpiece W is rotated, together with a main spindle 42, and a cutter 16 attached to a rotor 4 is rotated, thereby finishing bore internal surface Wa to a sphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerically controlled machine tool (NC machine tool) provided with a sphere processing device for processing the inner peripheral surface of a hole formed in a workpiece into a sphere, and a sphere processing method.

[0002]

2. Description of the Related Art As a true sphere processing apparatus for processing the inner peripheral surface of a hole formed in a workpiece into a true sphere, Japanese Utility Model Laid-Open No. 50-437 has been proposed.
An apparatus for processing a spherical portion of a connecting rod for a sewing machine disclosed in Japanese Unexamined Patent Application Publication No. 8 and No. 8-45602 are known. The spherical surface processing device and the spherical processing machine insert a cutting tool for spherical processing into a hole formed in a workpiece (hereinafter, referred to as a work) such as a connecting rod in advance, and rotate the work to apply the cutting tool to the work. The sphere finishing process is performed by rotating in a direction perpendicular to the rotation direction.

[0003] In the above-mentioned conventional spherical processing, a rough processing step of performing spherical processing on an inner peripheral surface of a hole formed in a work, and a true spherical finishing step of performing spherical finishing on an inner peripheral surface of a hole. And was done in a separate device. That is, after performing rough roughing on the inner peripheral surface of the hole formed in the work with a machine tool for roughing, the work is attached to a face plate of a spherical processing device, and the inner peripheral surface of the hole is subjected to the spherical finishing. I was The above-mentioned spherical surface processing device and spherical surface processing machine are excellent in that a spherical shape with high precision such as shape and surface roughness can be formed on the inner peripheral surface of the hole. Are performed by separate devices, the following problems occur.

A machine tool for roughing the inner peripheral surface of the hole,
A separate sphere processing device that performs sphere finishing is required, which makes it impossible to perform continually from roughing to sphere finishing. It will be expensive. The transfer of the work between the machine tool and the sphere processing device is performed manually, and it is difficult to automate from roughing to sphere finishing. When mounting the work on the face plate of the spherical surface processing device, the center of the rough-processed spherical portion formed on the work must exactly match the center of rotation of the face plate, but the center of the hole and the center of rotation of the face plate It is extremely difficult to completely match these, and not only the work load is large, but also processing defects due to misalignment are likely to occur. Further, even if the misalignment is within an allowable range, a sufficient allowance for finishing must be taken into account in rough machining in consideration of the misalignment, and the processing time of the true sphere processing is increased. Furthermore, the above-mentioned conventional spherical portion processing apparatus is a dedicated machine for manual operation, and has not been able to automate the processing. Furthermore, this spherical surface processing apparatus cannot detect wire breakage, and if automation of processing is attempted, there is a risk that a defective product will be produced by performing a spherical finishing process without knowing wire breakage. There is a problem. On the other hand, an NC machine tool can also machine a true spherical shape, but irregularities are formed on the true spherical surface due to the pulse distribution command for movement of the X axis and Z axis during circular interpolation.
It is difficult to process into a perfect spherical shape.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to solve the above-mentioned drawbacks of the conventional sphere processing apparatus. A numerically controlled machine tool and a true numerically controlled machine tool equipped with a true spherical machining device that can perform true spherical machining at high and inexpensive cost and that enables machining by automatic operation from roughing to spherical finishing. A ball machining method is provided.

[0006]

In order to solve the above-mentioned problems, a numerically controlled machine tool provided with a sphere processing device according to the present invention comprises:
What is claimed is: 1. A numerically controlled machine tool comprising a spherical processing device for processing an inner peripheral surface of a hole formed in a workpiece into a true spherical shape, comprising a bed, a headstock provided on the bed, and rotatably supporting a spindle. A tool rest that is provided on the bed and that can be moved relative to the spindle head in a spindle axis direction and a direction orthogonal to the spindle axis direction and positioned, and attached to the tool rest, A tool for roughing an inner peripheral surface into a spherical shape, a base provided at a position on the bed that does not interfere with the tool rest, and capable of moving and positioning relative to the head stock in the spindle axis direction. A base, a rotating body provided on the base, and rotating about an axis orthogonal to the main shaft axis, wire driving means for driving a wire wound on the rotating body, and a rotating body attached to the rotating body. The inner circumference of the hole by the rotation of the body A sphere processing device comprising a cutting tool for finishing the sphere into a true sphere, a spindle motor for driving the spindle and numerically controlling a drive motor for moving and positioning the tool rest and the base, and the wire driving means. And a control device for controlling the

The wire driving means includes a wire having one end moored to the fixed portion of the base, the wire being wound around the rotating body and a weight suspended from the other end, and a load applied to a part of the wire. To move the wire forward and backward against the weight of the weight, and to move the rotating body by a predetermined angle according to the moving length of the wire. . Further, the wire advance / retreat means is provided on a hydraulic cylinder provided on the base and a piston rod which is movable forward / backward of the hydraulic cylinder, and engages with the wire to advance / retreat the piston rod. Together with a wire engaging portion that applies a load to the wire.
An advancing and retreating member that reciprocates with the piston rod, a stopper provided on the advancing and retreating member, and abutting against a fixed portion of the base to restrict the advancing and retreating movement of the piston rod; And fixing means for positioning and fixing at any position along the line. Further, the base may be provided with a wire breakage detecting means for detecting that the wire is broken, and the wire breakage detecting means is provided on a fixing portion of the base, and the weight due to wire breakage is provided. It may be a sensor that detects the movement of the object.

Further, in the true spherical machining method according to the present invention, in order to machine the inner peripheral surface of the hole formed in the workpiece into a perfect spherical shape, a direction of a main shaft axis with respect to the main shaft and a direction orthogonal to the main shaft axis direction. A tool rest that is relatively movable in the direction of the spindle axis, a spherical machining method in a numerically controlled machine tool having a true spherical machining device that is relatively movable in the axis direction of the spindle. Attaching the work to the mounting means, rotating the spindle while retracting the true sphere processing device, moving the tool post by numerical control, and moving the tool post with a tool attached to the tool post. A step of roughing the inner peripheral surface of the hole into a spherical shape, and in a state where the tool rest is retracted, a true-sphere processing device is moved to the main spindle side so that a cutting tool for the true-sphere finishing is positioned at a predetermined position in the hole. The process of positioning Characterized in that comprising the step of performing a true sphere finishing the hole inner peripheral surface center by a predetermined angle rotation of the axis perpendicular to the cutting tool to the axis of the spindle to rotate the workpiece by the rotation of the main shaft.

[0009]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view for explaining the overall configuration of a numerically controlled machine tool provided with a true spherical machining apparatus according to the present invention.
FIG. 3 is a cross-sectional side view illustrating the configuration of the sphere processing device, FIG. 3 is a plan view of a part of the sphere processing device cut away, and FIG. It is explanatory drawing of a partial fracture | rupture of. In the following description, “one side” indicates the left side of the drawing, and “other side” indicates the right side of the drawing.

[Explanation of the Overall Configuration of a Numerically Controlled Machine Tool] First, the overall configuration of a numerically controlled machine tool provided with a true spherical machining apparatus according to the present invention will be described with reference to FIG. In this embodiment, the numerically controlled machine tool provided with the true sphere processing device is a numerically controlled lathe, and includes a bed 40, a headstock 41 provided on one side of the bed 40, and a rotatably supported by the headstock 41. Main shaft 42, a chuck 43 serving as a mounting means for a work W mounted on the tip of the main shaft 42, and a Z provided on the other side of the bed 40 and parallel to the main shaft axis with respect to the headstock 41.
A column 48 which is relatively movable in the axial direction and can be positioned, and a vertical guide 48a of the column 48
A tool rest 47 that is movable in the X-axis direction perpendicular to the Z-axis along the axis, and is provided rotatably on the tool rest 47;
A turret face plate 44 capable of indexing a predetermined tool T out of a plurality of tools T, T, T,... Mounted on the circumference to a machining position, and a headstock 41 provided on the other side of the bed 40. On the other hand, the sphere processing apparatus 1 is relatively movable in the Z-axis direction and can be positioned.
In addition, as long as the work W can be mounted on the main shaft 42, the mounting means is not limited to the chuck 43, and may be another type. The numerically controlled machine tool is not limited to the numerically controlled lathe, but may be any machine tool that can perform turning such as a turning center.

On the turret face plate 44, a turning tool (a cutting tool, a boring bar, etc.) for turning and drilling a work W attached to the chuck 43, and a tool T such as an end mill are mounted. Further, an inner diameter tool T for roughing the inner peripheral surface of the hole of the work W into a spherical shape is also mounted. The tool T performs a predetermined processing on the workpiece W by the movement of the column 48 in the Z-axis direction, the movement of the tool rest 47 in the X-axis direction, and the rotation of the main shaft 42. In the above description, the numerical control machine tool equipped with the true sphere processing device has been described as having the tool rest 47 moving in the X-axis direction on the column 48 movable in the Z-axis direction. The configuration is not limited to the above configuration as long as it can be relatively moved in the X-axis direction and the Z-axis direction and positioned at an arbitrary position. The sphere processing device 1 can move forward and backward in the Z-axis direction by a servo motor (drive motor) and a ball screw mechanism along a horizontal guide 46 provided on the bed 40, and can be positioned at any position. .
The true sphere processing apparatus 1 is provided with a cutting tool (not shown in FIG. 1) that is rotatable about an axis orthogonal to the Z-axis. Then, the cutting tool is inserted into the hole of the work W and positioned, and the work W is rotated about the axis while rotating the work W to perform the spherical finishing of the inner peripheral surface of the hole.

[Description of Spherical Ball Processing Apparatus] Next, details of the true sphere processing apparatus 1 will be described with reference to FIGS. A horizontal guide 46 (see FIG. 1) is provided on the base 2 of the true sphere processing device 1 so as to be able to move forward and backward by a servomotor, a ball screw mechanism or the like.
Is attached, and bolts 17 and
The base 10 is attached by 17. In this embodiment, the base 10 has a shaft 11 mounted on one side rotatably supported by a bearing 12 provided on one side of the base 2, and a head of a bolt 17 and a bolt hole 1.
2 can be rotated about the shaft 11 in a plane perpendicular to the plane of FIG.

[Structure of Cutting Tool Holder 3] On one side of the base 10, a cutting tool holder 3 for rotatably holding a cutting tool 16 for spherical finishing is mounted by bolts via a mounting member 3a. The blade holder 3 is detachably attached to the base 10 together with the mounting member 3a by removing the bolt, and the base 10 is positioned via the positioning member 10a.
At a predetermined position. At one end of the blade holder 3, a shaft 4a is provided in a direction orthogonal to the Z-axis, and a rotatable rotating body 4 is supported on the shaft 4a. In this embodiment, the rotation center of the shaft 4a is the main shaft 42.
And a true spherical surface having a center of curvature on the spindle axis can be finished. In addition, a wire groove is formed on the outer periphery of the rotating body 4 over the entire circumference, and a cutting tool 16 for performing a spherical finishing is formed to protrude in a radial direction. The cutting tool holder 3 has a wire guide groove 1 through which a wire 5 is inserted in the center.
4 are formed. On one side of the wire guide groove 14, two guide rollers 13a and 13b are arranged to face each other,
The wire 5 wound around the rotating body 4 is guided to the wire guide groove 14.

[Explanation of Wire] The rotation of the rotating body 4 is performed by the advance and retreat of the wire 5 wound around the wire groove of the rotating body 4. That is, when the wire 5 moves forward and backward, the rotating body 4 around which the wire 5 is wound rotates by a rotation angle corresponding to the amount of movement of the wire 5. A hook 8 is attached to one end of the wire 5. A bracket 7 is fixed to the bottom (fixed portion) of the base 2, and a hook 8 is hooked on a pin 7 a protruding from the bracket 7. The wire 5 extends from one opening 10a formed in the base 10 to the upper surface of the base 10, and guide pulleys 9a, 9b,
The guide 10 is guided by the guide groove 9c to the guide groove 14 of the blade holder 3, and is wound along the guide groove formed on the outer peripheral portion of the rotating body 4. Then, the base 10 is guided by the guide pulley 9d through the guide groove 14. The other opening 10 b leads to the inside of the base 2. A weight 6 is suspended from the other end of the wire 5, and a constant tension is always applied to the wire 5 by the weight 6. Note that in FIG.
Reference numerals a and 2b denote swing-preventing members that regulate the weight 6 from both sides so that the weight 6 suspended by the wire 5 in the base 2 does not swing.

[Explanation of Wire Break Detection Means] In this embodiment, the true sphere processing device 1 is provided with wire break detection means for detecting a wire break of the wire 5. The wire breakage detecting means may be a limit switch in which a contact always contacts the wire 5 or a tension meter for detecting a change in the tension of the wire 5 as long as the wire breakage can be detected. In this embodiment, a sensor (proximity switch) 30 for detecting whether the weight 6 has dropped due to a broken wire is provided at the bottom of the base 2. When the wire 5 is cut and the weight 6 falls to the bottom of the base 2, the sensor 30 detects the weight 6, and the sensor 30 detects the weight 6 from a numerical controller (hereinafter, referred to as an NC device) and a programmable controller (PLC). Output a signal to the control device. As a result, the control device determines that the wire 5 has been cut, and stops the spherical finishing process.

[Explanation of Wire Advancing / Retracting Means] Next, wire advancing / retracting means for moving the wire 5 forward and backward to rotate the rotating body 4 by a predetermined angle will be described. As long as the wire 5 can be moved forward and backward against the weight of the weight 6 by applying a load to an intermediate portion of the wire 5, the wire moving means is a combination of a pulley and a motor, and a cylinder. One end of the wire 5 may be connected to the tip of the piston rod, and the wire 5 may be pulled by moving the piston rod forward and backward. In this embodiment, a fluid pressure cylinder 20 (hereinafter, referred to as a cylinder 20) is attached to an attachment portion 19 which is a fixed portion formed inside the base 2, and a wire 5 provided on the cylinder 20 The piston rod 21 that can move forward and backward in the crossing direction can apply a load to the wire 5 by pushing a part of the wire 5 from the lateral direction.

That is, a retractable first piston rod 21 is provided on one side of the cylinder 20, and the distal end of the first piston rod 21 is engaged with one end of the wire 5 and is connected to the first piston rod 21. A wire engaging portion 22 that pushes the wire 5 from the side and applies a tensile force to the wire 5 as it moves to one side is provided. This wire engaging portion 22
In order to prevent the wire from being broken due to friction with the wire 5, it is desirable that the wire be rotatably attached to the tip of the first piston rod 21 or be made of a material having a smooth surface. The cylinder 20 is supplied with a working pressure fluid such as air or hydraulic oil via a flow control valve 18 provided inside the base 2. By adjusting the flow rate of the working pressure fluid, the forward / backward moving speed of the piston rod can be adjusted. When the wire engaging portion 22 pushes the wire 5 from the lateral direction, a tensile force acts on the wire 5, but since one end of the wire 5 is moored to the bracket 7 attached to the base 2, the wire engaging The wire 5 on the other end side of the engagement portion where the portion 22 and the wire 5 engage with each other is the weight 6
Will move while lifting. Since the wire 5 is wound around the rotating body 4 without slipping, the wire 5 rotates by the rotation angle corresponding to the moving length of the wire 5 in the same direction as the moving direction of the wire 5.

[Description of Mechanism for Adjusting Rotation Angle of Cutting Tool] In order to shorten the processing time of the true spherical finishing as much as possible, the rotating angle of the cutting tool 16 is in a necessary and sufficient range for performing the spherical finishing of the inner surface Wa of the hole. It is desirable to minimize it.
Therefore, if the rotation angle of the cutting tool 16 can be adjusted, even if the type and dimensions of the work W and the cutting tool 16 are changed, it is possible to always perform the perfect spherical finishing processing with the shortest processing time. In this embodiment, the sphere processing device 1 includes a rotation angle adjusting mechanism 24 that can change the rotation length of the cutting tool 16 by changing the length of movement of the wire 5 by adjusting the amount of advance and retreat of the first piston rod 21. Is provided. As shown in FIG. 4, the other side of the cylinder 20 moves forward and backward integrally with the first piston rod 21.
A piston rod 23 is provided and extends to the other side through a through hole 19a formed in the mounting portion 19. A screw shaft 28 is formed at the other end of the second piston rod 23, and a cylindrical stopper 26 having an inner peripheral surface of a through hole formed as a female screw portion 26b is screwed into the screw shaft 28.

The stopper 26 is formed with a screw hole 26a penetrating from the outer peripheral portion toward the female screw portion 26b, and a set screw 29 as a fixing means screwed into the screw hole 26a. It can be fixed at any position. As the fixing means, the above set screw 2
Not limited to 9 but may be a stopper pin or a double nut. Further, the configuration of the rotation angle adjusting mechanism 24 is not limited to the above, and the screw shaft 28 is used as a shaft, and the stopper 26 is inserted through the shaft so as to be freely positioned. The stopper 26 may be fixed at an arbitrary position on the shaft body by a fixing means. In the drawing, reference numeral 27 denotes a sensor (proximity switch) for detecting that the stopper 26 has moved to a position where it comes into contact with the mounting portion 19, and the sensor 27 detects the stopper 26 and outputs a detection signal to the NC device or the PLC. By doing so, the NC device determines that the blade 16 has rotated to the predetermined position.

When the cylinder 20 is driven to move the first piston rod 21 to one side, the first piston rod 2
The second piston rod 23 and the stopper 26 move to one side in conjunction with the movement of the first piston rod 23. The stopper 26 is the mounting portion 19
When the second piston rod 23 and the first piston rod 21 are in contact with each other, the movement of the second piston rod 23 and the first piston rod 21 is restricted. The angle can be adjusted. As shown in this embodiment, a scale 25 is provided in parallel with the direction in which the second piston rod 23 moves forward and backward, and a shoulder 26c formed on the stopper 26 is aligned with the scale 25. Accordingly, it is easy to determine how much the stopper 26 should be moved. When a smaller amount is set, a scale may be engraved on the outer peripheral portion of the stopper 26 along the circumferential direction, and the stopper 26 may be screw-adjusted.

[Description of Rotational Positioning Means of Base 10]
On the other side of the base 10, a base rotation positioning means 32 capable of rotating the base 10 by a small angle about the shaft 11 is provided. When the inner diameter of the hole slightly changes due to the exchange of the work W or the like, or when the radius of curvature of the true spherical surface is slightly changed, the base 10 is rotated by a small angle by the base rotation positioning means 32 and the cutting tool is rotated. The position of the tip 16 can be changed to cope with it. Hereinafter, the configuration of the base rotation positioning means 32 in this embodiment will be described. As shown in FIG. 3, a hole 10c is formed on the other side of the base 10, and a shaft 33 attached to the other side of the base 2 protrudes above the base 10 through the hole 10c. Hole 1 in base 10
Cylindrical bracket 34 having a through hole concentric with 0c
The ends of the adjusting screws 36a and 36b screwed into the screw holes 34a and 34b of the bracket 34 from both sides in the rotation direction of the base 10 are in contact with the shaft 33, respectively. A support 37 is attached near the bracket 34 on the upper surface of the base 10, and a dial gauge 35 is fixed to the support 37. At least at the time of adjustment, the contact 35a of the dial gauge 35 is
The dial gauge 35 is attached to the axis 33 on a circle having a radius of a straight line connecting the center of the axis 11 and the center of the axis 33 with the center of the center as the center.
Are in contact with each other within the measurement range.

According to the above embodiment, for example, the adjusting screws 36a,
When one (for example, the adjusting screw 36a) of the 36b is slightly loosened and the other (for example, the adjusting screw 36b) is tightened, the base 10 rotates a small angle counterclockwise around the shaft 11 on one side. The amount of rotation of the base 10 due to this rotation can be known by touching the pointer of the dial gauge 35.
Further, the distance from the center of the shaft 11 to the cutting tool 16 is set to 1,
If the distance from the center of the shaft 11 to the center of the shaft 33 is N times this, the amount of movement of the blade 16 can be easily known by dividing the reading of the dial gauge 35 by the N.

[Explanation of the Operation and Method of the Invention] Next, the operation of the numerically controlled machine tool provided with the spherical processing apparatus of the present invention having the above-described configuration will be described together with the spherical processing method of the present invention. [Step of Attaching Work to Spindle] First, the work W is attached to the chuck 43 of the spindle 42. When a hole is previously formed in the work W in a previous process such as when forming a material, the work W is attached to the chuck 43 such that the center of the hole coincides with the rotation center of the main shaft 42.

[Step of Roughing the Hole Inner Peripheral Surface into a Spherical Shape] Next, the main shaft 42 is rotated while the spherical processing device 1 is retracted to a position where it does not interfere with the tool rest 47. N not shown
The C device rotates the turret face plate 44 to find a tool T for roughing the inner peripheral surface of the hole into a spherical shape at a processing position where the work W can be processed. Then, the column 48 and the tool post 4
While the tool 7 is moved in the Z-axis direction and the X-axis direction, the inner peripheral surface of the hole is roughly machined with the tool T. In this case, after performing the roughing with the tool T, the true sphere finishing with the cutting tool 16 of the true sphere processing device 1 can be performed with the workpiece W attached to the main shaft 42. The feature is that the finishing allowance can be extremely reduced.

[Step of Inserting a Cutting Tool for Spherical Finishing into the Hole] After the roughing of the inner peripheral surface of the hole by the tool T is completed,
Next, the spherical inner surface of the hole is subjected to a sphere finishing process by the sphere processing device 1. FIG. 5 is a cross-sectional view illustrating a processing step of the spherical finishing processing. The column 48 and the tool rest 47 are moved in the Z-axis direction and the X-axis direction to retreat from the work W, and the spherical machining device 1 is moved to the horizontal guide 46 (FIG. 1).
), And insert the cutting tool 16 into the hole of the workpiece W. The movement of the sphere processing device 1 is stopped when the shaft 4a is inserted to the center of the hole, and the sphere processing device 1 is positioned at the position. At this time, the cutting tool 16 is on standby in a state in which it has been rotated to a position where the cutting tool 16 does not interfere with the work W (the position indicated by the symbol A in FIG. 5).

[Step of Performing True Spherical Finishing] While the workpiece W is being rotated together with the main shaft 42, the cutting tool 16 is rotated clockwise from the position indicated by the symbol A in FIG. Perform ball finishing. Cylinder 2
0, the first piston rod 21 is moved to one side, and the wire 5 is pushed by the wire engaging portion 22 from the lateral direction.
The wire 5 is deformed in the shape of the letter “C” and moves to one end while lifting the weight 6, and the cutting tool 16 is moved together with the rotating body 4 in FIG.
In the counterclockwise direction. The rotation speed of the rotating body 4 can be adjusted by adjusting the flow rate per hour of the working pressure fluid supplied from the flow rate adjustment valve 18. When the cutting tool 16 reaches a position where the cutting tool 16 has escaped from the hole of the work W (a position indicated by reference numeral B in FIG. 5), the stopper 26 provided on the second piston rod 23
9, the first piston rod 2
The movement of the first and second piston rods 23 to one side is restricted, and the rotation of the blade 16 stops.

The rotation of the blade 16 to the position B can be detected by detecting the stopper 26 which has moved to a position where the sensor 27 contacts the other side of the mounting portion 19. When the spherical finishing of the inner peripheral surface Wa of the hole is thus completed, the spherical processing device 1 is moved to the other side along the horizontal guide 46 and retracted from the workpiece W. Thereafter, when the cylinder 20 is driven to move the first piston rod 21 to the other side, the engagement between the wire engaging portion 22 and the wire 5 is released, and the wire 5 is returned to the original linear state by the weight 6. Return. By this operation, the blade 16 also returns to the position A. First
The return of the piston rod 21 to the other end is detected by a sensor (not shown) attached to the cylinder 20.
A series of operations ends. The driving of the cylinder 20 can be instructed by an auxiliary function (M code) or the like.
Can be commanded by a program. Further, driving by an MDI, a push button switch or the like from an operation panel (not shown) is also possible. In addition, a spindle motor or the like capable of controlling the rotation speed is used as a driving body for rotating the spindle 42, and the NC device controls the rotation speed of the spindle 42, so that the blade tool 16 is rotated.
It is also possible to always make the cutting speed when the hole inner peripheral surface Wa is spherically finished (constant peripheral speed processing) to perform a more accurate true spherical surface finishing.

When the wire 5 is cut off during the spherical finishing, the weight 6 falls to the bottom of the base 2. Since the falling of the weight 6 is detected by the sensor 30, the NC device determines that the wire is broken and immediately stops the spherical finishing. Even if the wire 5 breaks, the wire 5 can be easily removed simply by removing the hook 8 from the pin 7a.
Exchange is easy.

Although the preferred embodiment of the present invention has been described, the present invention is not limited to the above embodiment. For example, in the embodiment described above, the first piston rod 21 is moved to one side, and a part of the wire 5 is pushed to apply a tensile force to the wire 5, but the first piston rod 21 is moved to the other side. When the wire 5 is moved, a part of the wire 5 may be pulled by the wire engaging portion 22 to apply a tensile force to the wire 5.

[0030]

As described above, the present invention has the following advantages. For machine tools that perform drilling and roughing of the inner surface of a hole,
Since the sphere processing device that performs sphere finishing is provided integrally, two devices that have been separate units can be integrated, and equipment costs for sphere processing can be reduced. . By simply attaching a workpiece to a machine tool that performs rough machining of the inner periphery of a hole into a spherical shape, it is possible to automatically perform from rough machining to spherical finishing. Since there is no need to change the work, the hole center for roughing and the hole center for spherical finishing are always in the same state, eliminating the need to match the hole center of the work with the rotation center of the spindle. In addition, it is possible to obtain a sphere processing surface with extremely high accuracy such as sphericity, surface roughness, and processing diameter. In addition, the finishing allowance at the time of roughing can be minimized, so that the time for true sphere processing can be reduced. Since the device provided with the wire breakage detecting means automatically detects the wire breakage and automatically stops the spherical finishing, the production of defective products is prevented from being mass-produced and the production efficiency is improved. With the blade angle adjustment mechanism, the blade rotation angle can be adjusted according to the type of work or changes in hole dimensions, etc., and the true-sphere finishing is completed by rotating the blade within the minimum required range. The sphere processing time can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a numerically controlled machine tool including a true sphere processing device of the present invention.

FIG. 2 is a sectional side view illustrating a configuration of a true sphere processing apparatus.

FIG. 3 is a plan view in which a part of the true sphere processing device is broken.

FIG. 4 is an explanatory view of a partially broken rotation angle adjusting mechanism for adjusting the rotation angle of a cutting tool for finishing a sphere.

FIG. 5 is a cross-sectional view illustrating a processing step of the true spherical finishing processing.

[Explanation of symbols]

 W Work Wa Wafer inner peripheral surface T Tool 1 True sphere processing device 2 Base 3 Blade holder 3a Mounting member 4 Rotating body 4a Shaft 5 Wire 6 Weight 7 Bracket 8 Hook 9a to 9d Guide pulley 10 Base 10a, 10b Opening 10c Hole DESCRIPTION OF SYMBOLS 11 Shaft 12 Bearing 13a, 13b Guide roller 14 Guide groove 15 Mounting bolt 16 Cutting tool 17 Bolt 18 Flow control valve 19 Mounting part 20 Cylinder 21, 23 Piston rod 22 Wire engaging part 24 Rotation angle adjusting mechanism 25 Scale 26 Stopper 26a Screw hole 26b Female thread portion 26c Shoulder portion 27 Sensor 28 Screw shaft 29 Screw (fixing means) 30 Sensor (for detecting broken wire) 32 Base rotation positioning means 33 Shaft 34 Bracket 34a, 34b Screw hole 35 Dial gauge 35a Contact 36a, 36b Adjusting screw 3 Support base 40 bed 41 headstock 42 spindle 43 chuck (mounting means) 44 turret face plate 45 the tool 46 horizontal guide

Claims (7)

[Claims] 1. A numerically controlled machine tool provided with a spherical processing device for processing an inner peripheral surface of a hole formed in a workpiece into a spherical shape, comprising: a bed (40); A headstock (41) for rotatably supporting a spindle, and a blade provided on the bed, which is relatively movable with respect to the headstock in a spindle axis direction and a direction orthogonal to the spindle axis direction and can be positioned. A base (47), a tool (T) attached to the tool rest, for roughing the inner peripheral surface of the hole into a spherical shape, and a tool (T) provided at a position on the bed that does not interfere with the tool rest, A base (2) that can be moved relative to the main shaft axis direction and positioned therewith; and a rotating body provided on the base and rotating about an axis (4a) orthogonal to the main shaft axis ( 4) and a wire for driving the wire wound around the rotating body. A sphere processing device (1) comprising a driving means, a cutting tool (16) attached to the rotator and finishing the inner peripheral surface of the hole into a sphere by rotation of the rotator; A numerical control of a drive motor for moving and positioning the table, and a control device for controlling a spindle motor for driving the spindle and a control device for controlling the wire driving means. machine. 2. A wire (5) having one end moored to a fixed portion of the base, a wire wound around the rotating body, and a weight (6) suspended from the other end. Means for applying a load to a part of the wire to move the wire forward and backward against the weight of the weight, and for moving the rotating body by a predetermined angle in accordance with the moving length of the wire; A numerically controlled machine tool comprising the sphere processing device according to claim 1, comprising: 3. The means for moving the wire forward and backward is provided on a hydraulic cylinder (20) provided on the base and a piston rod (21) which can move forward and backward on the hydraulic cylinder. Numerical control provided with a true sphere processing device according to claim 2, comprising a wire engaging portion (22) for applying a load to the wire as the piston rod moves forward and backward by engaging with the piston rod. Machine Tools. 4. A moving means for moving the wire forward and backward together with the piston rod, a moving means for moving the wire forward and backward, and a fixing part of the base for the wire moving means. A stopper (26) for restricting advancing and retreating of the piston rod by abutting; and a fixing means (29) for positioning and fixing the stopper at an arbitrary position along the reciprocating member; And a rotation angle adjustment mechanism (24) of a cutting tool for determining a rotation angle of the rotating body (4) by adjusting a moving amount of the piston rod by changing a fixing position of the stopper. A numerically controlled machine tool comprising the spherical processing device according to claim 3. 5. The true sphere processing apparatus according to claim 1, wherein the base is provided with a wire breakage detecting unit that detects that the wire is broken. Numerically controlled machine tool equipped with 6. The sensor according to claim 5, wherein the wire break detecting means is a sensor (30) provided on a fixing portion of the base and detecting movement of the weight due to wire break. Numerically controlled machine tool equipped with a spherical processing device. 7. A tool rest which is relatively movable in a main shaft axis direction and a direction orthogonal to the main shaft axis direction with respect to the main shaft in order to machine an inner peripheral surface of a hole formed in a workpiece into a true spherical shape. A spherical machining method in a numerically controlled machine tool having a true spherical machining device that is relatively movable in the spindle axis direction, wherein the workpiece mounting means provided on the spindle of the numerically controlled machine tool has Attaching the workpiece, rotating the spindle while retracting the true spherical machining apparatus, moving the tool rest by numerical control, and moving the tool rest in the hole of the workpiece with the tool attached to the tool rest. A step of roughing the peripheral surface into a spherical shape, and, with the tool rest retracted, moving a true sphere processing device to the main spindle side to position a cutting tool for true sphere finishing at a predetermined position in the hole. And the rotation of the spindle Rotating the workpiece and rotating the cutting tool by a predetermined angle around an axis orthogonal to the axis of the main shaft to perform a spherical finishing process on the inner peripheral surface of the hole. A true spherical machining method for machine tools.