JP4605936B2 - Turning method for multiple locations on the same circumference - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of turning at an eccentric position of a workpiece using a lathe, and machining a plurality of holes and a plurality of protrusions arranged on a circumference with a tool mounted on a lathe tool post. It is about the method.
[0002]
[Prior art]
In general, machining of a hole or a cylindrical shaft at a position on the spindle axis of a workpiece on a lathe is performed by turning using a cutting tool mounted on a tool post of the lathe. On the other hand, drilling of a workpiece can be performed by mounting a drilling tool such as a drill or a boring head on a turret equipped with a rotary tool driving device. According to this method, it is possible to easily process a plurality of holes on the same circumference by using a lathe equipped with a spindle indexing means and a rotary tool driving device.
[0003]
However, holes machined with a drill or a boring head have lower machining accuracy than holes that have been turned. In addition, with a rotary tool, a hole having a complicated cross-sectional shape in the axial direction (for example, a tapered hole with a step) cannot be processed unless a dedicated tool is used. On the other hand, if machining is performed by turning to the center of the workpiece, the machining accuracy can be increased, and a complicated axial cross-section hole can be accurately machined by controlling the movement position of the tool post in the Z-axis direction and X-axis direction. Can do.
[0004]
Therefore, an eccentric chuck provided with an index mechanism for a chuck claw by a cam is provided in order to realize hole machining by turning at equal divided positions on the same circumference of the workpiece. As shown in FIG. 6, this eccentric chuck can hold the workpiece W on the axis 2 that is eccentric with respect to the main spindle axis 3 of the lathe, and the chuck claw 44a is eccentric by a cam mechanism built in the chuck. The rotation index can be indexed by a predetermined angle around the axis 2 that has been made. Therefore, if this type of chuck is used, holes can be drilled by turning at equal intervals on the same circumference of the workpiece.
[0005]
On the other hand, in order to reduce the time and manpower required to transport and unload workpieces between machines by making it possible to perform workpieces that require various machining such as turning, drilling, and plane machining on the same machine stand. A turret tool post equipped with a rotary tool drive unit is equipped with a lathe that can move and position in the Z, X and Y axis directions, and a rotary tool axis with an automatic tool changer that can turn around the turret tool post and the Y axis. Lathes equipped with two types of tool post, such as a tool post, have been provided. With this type of lathe, it is possible to perform various types of machining including planar machining on the workpiece by moving the tool post in the Y-axis or attaching a milling tool to the rotary tool axis.
[0006]
[Problems to be solved by the invention]
The eccentric indexing chuck 44 equipped with the chuck claw indexing mechanism has a built-in special indexing mechanism, so that the chuck is expensive and the cam is mechanically indexed. The angle cannot be indexed and machining can only be performed at a position where the circumference is equally divided, and even when machining is performed on the same circumference, the chuck can be replaced. It is necessary to change the setup, and the chuck cylinder for opening and closing the chuck jaws mounted on the lathe spindle has a special structure, so a lathe with a corresponding structure must be used, and it is practical for general lathes. There are problems such as being unable to do.
[0007]
The present invention uses a turret lathe equipped with a tool post capable of controlling the position in the Y-axis direction and a turret lathe equipped with an angle indexing means for a rotating tool axis, without using a special chuck or tool. It is an object of the present invention to provide a means for realizing high-precision machining by turning at positions on the same circumference.
[0008]
[Means for Solving the Problems]
The turning method for a plurality of locations on the same circumference of the present invention includes a rotation angle indexing means for the main shaft 1, a Z-axis direction (main-axis direction), an X-axis direction (main-axis perpendicular direction), and a Y-axis direction (Z-axis and Using a lathe equipped with a turret tool post 6 that can be moved and positioned in the direction perpendicular to the X axis), an eccentric chuck 4 is mounted on the spindle 1, and a work chuck 8 and a cutting tool 9 are mounted on the turret 7 of the tool post 6. The workpiece W is gripped by the eccentric chuck 4 and turned to a position on the spindle axis of the workpiece W by the cutting tool 9, and then the workpiece W is transferred from the eccentric chuck 4 to the workpiece chuck 8, and then the spindle 1 is predetermined. The workpiece chuck 8 is opposed to the gripping position of the eccentric chuck 4 by rotating the tool post 6 in the X-axis and Y-axis directions, the workpiece W is transferred from the workpiece chuck 8 to the eccentric chuck 4, and the position of the workpiece W on the spindle axis Next turning Is that performing a factory.
[0009]
Another method of the present invention that achieves the same problem is a lathe having a tool post 32 having a rotary tool shaft 36 and a turret tool post 6, wherein the rotary tool shaft 36 has a Y axis in the ZX plane. Using a lathe capable of determining the turning angle of the rotation and having an indexing means for the rotation angle of the shaft itself, the eccentric chuck 4 is mounted on the spindle, the work chuck 8 is mounted on the rotary tool shaft 36, and the turret tool post 6, with the cutting tool 9 attached to the workpiece and holding the workpiece W on the eccentric chuck 4, the workpiece 9 is turned to a position on the spindle axis of the workpiece W, and then the workpiece W is transferred from the eccentric chuck 4 to the workpiece chuck 8. Delivery, the rotary tool shaft 36 is rotated by a predetermined angle, the workpiece W is delivered from the workpiece chuck 8 to the eccentric chuck 4, and then the next turning process is performed at a position on the spindle axis of the workpiece W.
[0010]
[Action]
In the method of the present invention, the radius of the circumference of the machining position arranged on the same circumference is determined by the distance e between the gripping central axis 2 of the eccentric chuck 4 and the spindle axis 3 of the lathe equipped with the chuck. The This is the same as the case where the eccentric indexing chuck 44 shown in FIG. 6 is used. However, since the complicated indexing mechanism is not built in, the chuck claw 4a and the chuck body 4b are arranged along the guide in the diameter direction. By making it movable and fixed, it is also possible to change the diameter of the circumference of the machining location without exchanging the eccentric chuck 4 (see FIG. 3).
[0011]
In the method using the Y-axis movement of the tool post, the interval on the circumference of the machining location is determined by the index angle of the spindle 1 on which the eccentric chuck 4 is mounted. Since the angle of the main shaft is numerically controlled by the NC device, an arbitrary angle can be randomly determined. Therefore, machining at a position where the circumference is unevenly divided can be easily realized. When the spindle 1 is rotated by a desired angle in order to machine the next part after machining one place, the gripping center axis 2 moves in the X-axis direction and the Y-axis direction. The tool post is moved in the X-axis and Y-axis directions in order to make the work chuck 8 mounted on the X-axis facing the workpiece chuck 8.
[0012]
In the method of machining using a lathe equipped with a rotary tool axis having a rotary indexing means, the interval between machining points arranged on the circumference by the indexing operation of the rotary tool axis after the workpiece is transferred to the work chuck. Is set. Accordingly, by performing the angle indexing of the rotary tool shaft with the NC device, it is possible to perform turning at an arbitrary position on the same circumference. In this case, since the spindle rotation remains fixed, it is not necessary to move the tool post in the X-axis direction and the Y-axis direction after indexing the rotary tool axis.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show a first embodiment of the present invention. In FIG. 1, an eccentric chuck 4 in which a workpiece gripping center axis 2 is eccentric by e with respect to a spindle axis 3 is attached to a lathe spindle 1. The workpiece W is held by a chuck claw 4a arranged around the gripping central axis 2, and the diameter of the workpiece W is larger than twice the eccentric amount e. A work chuck 8 is attached to one place of a tool station of a turret 7 mounted on a turret tool post 6 of a lathe, and a hole cutting tool 9 is attached to another tool station. The turret tool post 6 moves in the spindle axis direction (Z-axis direction), the cutting feed direction of the turret tool post 6 (X-axis direction), and the Y-axis direction perpendicular to the Z-axis and the X-axis (the direction perpendicular to the drawing sheet). The position is controlled by the NC device 10. The rotation angle of the spindle 1 around the spindle axis 3 is controlled by the NC device 10.
[0014]
FIG. 2 is a cross-sectional view showing an example of the work chuck 8 mounted on the turret 7. The work chuck 8 includes a chuck opening / closing cylinder 11, and its piston 12 is urged by a spring 13 in the advancing direction. One end of a bell crank 17 pivotally supported by the case 16 is engaged in the circumferential groove 15 provided at the tip of the piston rod 14, and the other end is in a recess 19 provided behind the chuck claw 18. Is in attendance. When pressure fluid is supplied from the port 20, the piston 12 moves backward, and the action of the bell crank 17 moves the chuck claw 18 toward the gripping central axis 2 to grip the workpiece.
[0015]
The tool post 6 that pivotally supports the turret 7 is provided with a joint 21 for supplying a coolant (cutting fluid) to a machining position of the tool mounted on the turret. Open toward the back of the. The supply hole 22 is provided with a valve body 24 urged in the opening direction by a spring 23. On the other hand, a coolant receiving port 25 facing the supply hole 22 is provided on the back of the inner part of each tool station of the turret 7, and this coolant receiving port communicates with the mounting surface 26 of the tool mounting station of the turret. Yes. The port 20 of the cylinder of the work chuck is open to the attachment surface to the turret. When the work chuck 8 is attached to the turret 7, the port 20 communicates with the cutting fluid receiving port 25, and the work chuck 8 is connected to the work side. When the turret 7 is pulled and locked to the tool post 6 side, it communicates with the coolant supply hole 22 of the tool post. Therefore, in this state, by supplying the coolant to the coolant supply hole 22 or supplying the pressurized air, the chuck claw 18 of the workpiece chuck is closed and the workpiece is gripped.
[0016]
FIG. 3 is an explanatory view of a work machined by the method of the first embodiment as seen from the main axis direction. Hereinafter, the method of the first embodiment will be described with reference to FIGS. The first hole 30a is processed at a position on the spindle axis of the workpiece W held by the eccentric chuck 4. After machining, the spindle is stopped at the origin angle position, the turret 7 is turned to index the work chuck 8, and the work chuck 8 is made to face the work W in the eccentric position by moving the tool post 6 in the X-axis direction. , Close the work chuck 8 and open the eccentric chuck 4, and then move the tool post in the Z-axis direction to transfer the work W from the eccentric chuck 4 to the work chuck 8.
[0017]
Next, the main shaft 1 is rotated by an angle θ required for the next drilling (see FIG. 3B). By this rotation, the gripping central axis 2 of the eccentric chuck is shifted from the initial position by e (1-cos θ) in the X-axis direction and e · sin θ in the Y-axis direction. Here, e is the radius of the circumference where the hole to be processed is arranged, that is, the amount of eccentricity from the spindle axis 3 to the gripping center axis 2. Therefore, the tool post 6 is moved in the X-axis direction and the Y-axis direction by the amount of deviation, the tool post 6 is moved to the eccentric chuck 4 side, the eccentric chuck 4 is closed, the work chuck 8 is opened, and the tool post 6 is retracted. As a result, the workpiece W is transferred from the workpiece chuck 8 to the eccentric chuck 4. Since the workpiece does not rotate while being held by the workpiece chuck 8, when the workpiece is newly held by the eccentric chuck, the workpiece is relatively rotated in the opposite direction by the rotation angle θ of the main shaft. If drilling is performed on the spindle axis of the workpiece at the position, the first hole 30a and the next hole 30b are processed at positions separated by an angle θ on the same circumference.
[0018]
The rotation angle θ of the spindle can be freely set by the NC device 10, and the drilling on the spindle axis is performed by turning the tool rest in the Z-axis direction and the X-axis direction using a drill bit. Therefore, even a hole having a complicated axial sectional shape can be processed with high accuracy.
[0019]
4 and 5 are views showing a second embodiment of the present invention. The spindle 1 is mounted with an eccentric chuck 4 similar to that of the first embodiment, and the workpiece W is gripped. The lathe used in the second embodiment includes a first tool post 6 and a second tool post 32. The first tool post 6 is a turret tool post, and a tool 9 for hole machining is mounted on the turret 7. Yes. The second tool post 32 is equipped with a rotary tool driving device 35 capable of controlling the turning angle around a turning shaft 34 in the Y-axis direction (perpendicular to the plane of the drawing), and the rotary tool driven by this rotating tool driving device. A work chuck 8 is attached to the tip of the shaft 36 by an automatic tool changer (not shown). The first tool post 6 and the second tool post 32 can be moved and positioned at least in the Z-axis direction and the X-axis direction.
[0020]
FIG. 5 is a cross-sectional view showing an example of the structure of the work chuck 8 of the second embodiment. The work chuck of the second embodiment includes a grip portion 38 that is gripped by the hand of the automatic tool changer, and a shank 39 that is attached to the rotary tool shaft, like other tools that are automatically changed. Yes. In the general structure of the rotary tool shaft, the coolant is supplied to the tool blade edge through the center hole of the rotary tool shaft. The structure of the chuck cylinder 11 or bell crank 17 and chuck claw 18 of the work chuck 8 in FIG. 5 is the same as that of the work chuck of the first embodiment shown in FIG. In the case of FIG. 5, the port 20 of the chuck cylinder opens in the axial center portion of the shank 39. In the embodiment of FIG. 5, the tip of the shank 39 is spread outward by a ball provided on a pull rod that advances and retreats on the central axis of the rotary tool shaft, and is fixed to the rotary tool shaft 36. The chuck claw 18 is closed by supplying the coolant or pressurized air from the coolant supply hole of the rotary tool shaft.
[0021]
Hole machining by turning the workpiece W to a position on the spindle axis is performed by a hole machining tool 9 mounted on the first tool post. When the first hole machining is completed, the spindle 1 is stopped at the position of the origin angle, the rotary tool shaft 36 is turned in the direction toward the workpiece W, the second tool post 32 is advanced, and the workpiece chuck 8 is moved to the spindle axis. Is opposed to the workpiece W in an eccentric position. Then, the workpiece chuck 8 is brought close to the workpiece W, the workpiece chuck 8 is closed, the eccentric chuck 4 is opened, and the workpiece is transferred from the eccentric chuck to the workpiece chuck. In this state, the NC tool 10 rotates the rotary tool shaft 36 by a predetermined angle θ, then closes the eccentric chuck 4 and opens the work chuck 8 so as to be separated from the work, whereby the work W is rotated by a predetermined angle. In this state, if the next hole processing is performed at the position of the spindle axis of the workpiece, the first hole 30a and the next hole 30b are held while the workpiece W is being gripped. Processing is performed at a position on the same circumference separated by the rotation angle θ of the rotary tool shaft 36.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a lathe used in the first embodiment. FIG. 2 is a schematic cross-sectional view of a work chuck. FIG. 3 is an explanatory view of the method of the first embodiment viewed from the direction of the spindle axis. 4 is a schematic plan view of a lathe used in the second embodiment. FIG. 5 is a schematic sectional view of the work chuck of the second embodiment. FIG. 6 is an explanatory diagram of a conventional eccentric indexing chuck. Explanation of]
1 Spindle 4 Eccentric chuck 6 Tool post 7 Turret 8 Work chuck
37 Work chuck

Claims (2)

Using a lathe equipped with a rotation angle indexing means for the spindle (1) and a turret tool post that can be moved and positioned in the Z, X and Y axis directions, an eccentric chuck (4) is mounted on the spindle, and the turret (7) A workpiece chuck (8) and a tool (9) are mounted on the workpiece, the workpiece is held by the eccentric chuck, and turning is performed at a position on the spindle axis of the workpiece with the tool, and then the workpiece is moved from the eccentric chuck to the workpiece. Next, the spindle is rotated by a predetermined angle, and the work chuck is made to face the gripping position of the eccentric chuck by the X-axis and Y-axis movement of the tool post (6), and the workpiece is transferred from the work chuck to the eccentric chuck. A turning method for a plurality of places on the same circumference, characterized in that the next turning process is performed at a position on the spindle axis. Using a lathe equipped with a turret tool post equipped with a rotary tool shaft capable of positioning the turning angle around the Y axis in the ZX plane and provided with a rotation angle indexing means, and an eccentric chuck ( 4) is mounted, the work chuck (8) is mounted on the rotary tool shaft, the tool (9) is mounted on the turret tool post, and the work spindle is held by the tool while the work is held on the eccentric chuck. Turn to the position on the axis, then deliver the workpiece from the eccentric chuck to the work chuck, rotate the rotary tool axis by a predetermined angle, deliver the workpiece from the workpiece chuck to the eccentric chuck, and then position the workpiece on the spindle axis A method of turning at a plurality of locations on the same circumference, characterized by performing the following turning process.

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