JP6645041B2 - Cutting device and cutting method - Google Patents

Description

  The present invention relates to a cutting device and a cutting method.

  In cutting equipment, when cutting a workpiece made of a difficult-to-cut material such as titanium alloy or inconel with a cutting tool such as an end mill or cutting tool, the cutting edge of the cutting tool comes into contact with the workpiece for a long time with large cutting resistance. Therefore, high-temperature cutting heat is likely to be generated at the contact portion of the cutting edge, and the tool life may be shortened.

  Therefore, for example, in Patent Literature 1, the rotation axis of a rotatable round piece-shaped cutting tool is arranged parallel to the cutting feed direction, and the workpiece is cut with the tool end face being a rake face while rotating the cutting tool. Rotary cutting methods have been proposed. In this rotary cutting method, since the cutting tool is rotating, the cutting heat generated on the cutting edge is dispersed over the entire circumference, and the tool life can be improved.

JP 2006-68831 A

  In the above-described rotary cutting method, since the connected chips continuously flow out, when the chips are entangled with the spindle or the workpiece, a problem such as a failure of the cutting device occurs. With a cutting tool provided with a chip breaker or the like, the above problem can be solved, but the tool cost tends to increase because the tool shape is a special shape. Further, a device capable of cutting chips during cutting has been proposed (see Japanese Patent Application Laid-Open Nos. 5-50301 and 2009-208162), but it is a cutting device using a cutting tool as a cutting tool. In addition, when a workpiece made of a difficult-to-cut material is cut, the tool life may be shortened.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cutting device and a cutting method that can separate chips generated during cutting and can improve tool life. I do.

(Cutting equipment)
The cutting device of the present invention includes an annular tool having an annular cutting edge, a tool spindle for attaching the annular tool, and rotating the annular tool around the axis of the annular tool, and a workpiece holding table for holding the workpiece. A control device that controls the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle, the control device includes: the tool spindle and the workpiece holding table, The outer peripheral surface is a rake face, and the end face of the annular tool is arranged in a relative positional relationship to be a flank, and the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece is 0 or more The machining of the workpiece with the annular tool while varying the speed ratio so as to achieve the above, and the machining of the workpiece with the annular tool while keeping the speed ratio constant are alternately performed.

In the cutting process using this annular tool, the outflow shape, outflow direction, outflow angle, and outflow speed of the chip fluctuate by changing the speed ratio during the cutting, and the chip is pulled to the outer peripheral surface of the tool body of the annular tool. tangling with respect to the tool spindle and workpiece chips can be prevented is divided being.

(Cutting method)
The cutting method of the present invention includes an annular tool having an annular cutting edge, a tool spindle for attaching the annular tool, rotating the annular tool around the axis of the annular tool, and a workpiece holding table for holding the workpiece. Wherein the tool spindle and the workpiece holding table are arranged in a relative positional relationship such that an outer peripheral surface of the annular tool becomes a rake face, and an end face of the annular tool becomes a flank face. Arranging the workpiece with the annular tool while changing the speed ratio so that the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece becomes 0 or more. And a machining step of alternately machining the workpiece with the annular tool while keeping the speed ratio constant . According to the cutting method of the present invention, the same effects as those of the above-described cutting device can be obtained.

It is a figure showing the whole cutting device composition concerning an embodiment of the invention. It is a front view which shows the annular tool used for the cutting device of FIG. FIG. 2B is a side view of the annular tool of FIG. 2A. It is a flowchart for demonstrating acquisition of the fluctuation | variation pattern of the speed ratio of the peripheral speed of an annular tool, and the feed speed of a workpiece. It is a figure which shows the 1st fluctuation pattern which changes a speed ratio periodically and constantly. It is a figure which shows the 2nd fluctuation | variation pattern which fluctuates a speed ratio constantly constantly. It is a figure which shows the 3rd fluctuation pattern which changes a speed ratio constantly constantly. It is a figure which shows the fluctuation | variation pattern which makes a speed ratio constant during the periodical fluctuation | variation of a speed ratio, without always changing a speed ratio. It is a figure which shows the variation pattern of another example which changes a speed ratio periodically and constantly. It is a flowchart for demonstrating the cutting method in the speed ratio of a 1st fluctuation pattern using an annular tool. It is a perspective view which shows the outflow state of the chip when a speed ratio becomes the maximum value. FIG. 6A is a view seen from a direction perpendicular to the rotation axis of the annular tool and parallel to the rotation axis of the workpiece. It is a perspective view which shows the outflow state of the chip when the speed ratio changes from the maximum value to the minimum value. FIG. 7B is a view of FIG. 7A as seen from a direction perpendicular to the rotation axis of the annular tool and parallel to the rotation axis of the workpiece. It is a perspective view which shows the outflow state of the chip when the speed ratio changes from the minimum value to the maximum value. FIG. 8A is a view seen from a direction perpendicular to the rotation axis of the annular tool and parallel to the rotation axis of the workpiece. FIG. 3B is a view perpendicular to the rotation axis of the workpiece and showing the annular tool in a traverse direction feed by the annular tool of FIGS. 2A and 2B and viewed from the front, in a direction perpendicular to the rotation axis of the workpiece. FIG. 9A is a view of FIG. 9A in a direction perpendicular to the rotation axis of the workpiece and the annular tool as viewed from the side. FIG. 2B is a diagram showing a plane cutting state by the annular tool of FIGS. 2A and 2B as viewed from a direction perpendicular to a plane. It is the figure which looked at FIG. 10A from the direction parallel to a plane.

(1. Machine configuration of cutting equipment)
As shown in FIG. 1, the cutting apparatus 1 includes a work holding table 10, a bed 20, a tailstock 30, a carriage 40, a feed table 50, a tilt table 60, a tool table 70, Device 80 and the like. In the following description, the direction of the rotation axis Rw of the rotation spindle 11 provided on the workpiece holding table 10 is the Z-axis direction, and the direction orthogonal to the rotation axis Rw direction of the rotation spindle 11 in the horizontal plane is the X-axis line. The direction orthogonal to the direction, the Z-axis direction, and the X-axis direction is referred to as the Y-axis direction.

  The work holding table 10 is formed in a rectangular parallelepiped shape, and is set on the bed 20. The work holding table 10 is provided with a rotating spindle 11 rotatable about a rotating spindle Rw. A chuck 12 having a claw 12a that can grip a peripheral surface on one end side of the workpiece W is attached to one end side of the rotary spindle 11. The rotating spindle 11 is driven to rotate by a spindle motor 13 accommodated in the work holding table 10.

  The bed 20 is formed in a rectangular parallelepiped shape, and is set on the floor so as to extend in the Z-axis direction from the work holding table 10 below the rotary spindle 11. A pair of Z-axis guide rails 21a and 21b, on which the tailstock 30 and the carriage 40 can slide, are provided on the upper surface of the bed 20 so as to extend in the Z-axis direction and to be parallel to each other. Further, the bed 20 is provided with a Z-axis ball screw (not shown) for driving the carriage 40 in the Z-axis direction between the pair of Z-axis guide rails 21a and 21b. A rotary Z-axis motor 22 is provided.

  The tailstock 30 is provided on a pair of Z-axis guide rails 21a and 21b so as to be movable in the Z-axis direction with respect to the bed 20. The tailstock 30 is provided with a center 31 capable of supporting the free end surface of the workpiece W held by the chuck 12. That is, the center 31 is provided on the tailstock 30 such that the axis of the center 31 coincides with the rotation axis Rw of the rotation spindle 11.

  The carriage 40 is formed in a rectangular plate shape, and is provided between the work holding table 10 and the tailstock 30 on the pair of Z-axis guide rails 21a and 21b so as to be movable in the Z-axis direction with respect to the bed 20. It is provided between them. On the upper surface of the carriage 40, a pair of X-axis guide rails 41a and 41b, on which the feed table 50 can slide, are provided so as to extend in the X-axis direction and parallel to each other. Further, the carriage 40 is provided with an X-axis ball screw (not shown) for driving the feed bar 50 in the X-axis direction between the pair of X-axis guide rails 41a and 41b. An X-axis motor 42 for rotationally driving is provided.

  The feed base 50 is formed in a rectangular plate shape, and is provided on the pair of X-axis guide rails 41a and 41b so as to be movable in the X-axis direction with respect to the carriage 40. On the upper surface of the feed table 50, a pair of tilt table support portions 61 that support the tilt table 60 are arranged at predetermined intervals in the Z-axis direction.

  The tilt table 60 is formed in a cradle shape, and is supported by a pair of tilt table support portions 61 so as to be able to rotate (swing) around the tilt axis Rc with respect to the feed table 50. A tool rest 70 is arranged on the upper surface of the tilt stand 60. A tilt motor 62 that rotates (oscillates) the tilt table 60 around the tilt axis Rc is disposed on one tilt table support 61.

  A tool spindle 71 is provided on the tool rest 70 so as to be rotatable around a tool axis Rt. A tool motor 72 for rotating the tool spindle 71 around the tool axis Rt is disposed on the tool rest 70. An annular tool 90 described later is chucked to the tool spindle 71. Further, the tool rest 70 is provided with a supply nozzle 73 that is connected to a cutting oil supply device (not shown) that supplies cutting oil for cooling the annular tool 90.

  The control device 80 includes a spindle rotation control unit 81, a carriage movement control unit 82, a slide movement control unit 83, a tilt control unit 84, and a tool rotation control unit 85. Here, each of the units 81 to 85 can be configured by individual hardware, or can be realized by software.

The main shaft rotation control unit 81 controls the main shaft motor 13 to drive the rotary main shaft 11 to rotate at a predetermined rotation speed.
The carriage movement controller 82 controls the Z-axis motor 22 to move the carriage 40 back and forth along the pair of Z-axis guide rails 21a and 21b.

The feed base movement control unit 83 controls the X-axis motor 42 to reciprocate the feed base 50 along the pair of X-axis guide rails 41a and 41b.
The tilt controller 84 controls the tilt motor 62 to rotate (swing) the tilt table 60.
The tool rotation controller 85 controls the tool motor 72 to rotate the annular tool 90 together with the tool spindle 71.

  The control device 80 controls the tilt motor 62 to incline the annular tool 90 at a predetermined angle, controls the spindle motor 13 and the tool motor 72, rotates the workpiece W and rotates the annular tool 90, The outer peripheral surface of the annular tool 90 is cut into the workpiece W by controlling the axis motor 42 and the Z-axis motor 22 to relatively move the workpiece W and the annular tool 90 in the X-axis direction and the Z-axis direction. To cut the workpiece W.

(2. Shape of annular tool)
As shown in FIGS. 2A and 2B, the annular tool 90 includes a tool body 91 having a truncated right circular cone shape, and a cylindrical tool shaft 92 extending from a small-diameter end surface 91 a on the root side of the tool body 91. The outer peripheral surface of the tool main body 91 is formed as a rake face 91b in the shape of a right circular cone, and the large-diameter end face of the tool main body 91 is formed as a flat flank 91c. The ridge formed by the rake face 91b and the flank 91c of the tool main body 91 is formed as a continuous circular shape, that is, a circular cutting edge 91r that is not divided in the middle. The cutting edge angle α formed by the rake face 91b and the flank face 91c of the annular tool 90 when viewed from a direction perpendicular to the tool axis Rt is 45 degrees or more, preferably 70 degrees, in order to maintain the strength of the cutting edge 91r. From 80 degrees.

(3. Cutting method using an annular tool)
Here, in the cutting method using the annular tool 90, as shown in FIGS. 6A and 6B, the speed between the peripheral speed of the outer peripheral surface of the tool body 91 of the annular tool 90 and the moving speed of the cutting point Pt of the workpiece W. By setting the ratio (peripheral speed of the outer peripheral surface of the tool main body 91 / moving speed of the cutting point Pt of the workpiece W) to +1.0 or more (peripheral speed ≧ moving speed), the chips K1 are removed from the tool body 91 of the annular tool 90. The effect of being pulled by the outer peripheral surface of the can be obtained. Thereby, the chip K1 is cut off, so that it is possible to prevent the chip K1 from being entangled with the tool spindle 71 or the workpiece W. The moving speed of the cutting point Pt of the workpiece W in this example is a speed obtained by combining the feed speed of the annular tool 90 and the peripheral speed of the workpiece W. Further, a positive speed ratio is when the rotation direction of the annular tool 90 is rt, and a negative speed ratio is when the rotation direction of the annular tool 90 is opposite to rt.

  However, in the cutting method using the annular tool 90, if the cutting is continued at a constant speed ratio of +2.0, the frictional work between the annular tool 90 and the chip K1 increases, and the tool life decreases. Tend to. Then, it was found that when the speed ratio was changed during the cutting, the effect of extending the tool life was obtained, and at the same time, the effect of cutting the chips K1 was obtained. The effect of extending the tool life is that the friction work between the annular tool 90 and the chip K1 is smaller when the speed ratio is changed during the cutting process than when the speed ratio is fixed at +2.0. It is because it becomes. Further, the cutting action of the chip K1 is because the outflow shape, the outflow direction, the outflow angle, and the outflow speed of the chip K1 fluctuate by changing the speed ratio during the cutting.

  The change in the speed ratio is obtained by changing the peripheral speed of the outer peripheral surface of the annular tool 90 by changing the peripheral speed of the outer peripheral surface of the annular tool 90. Chips K1 can be reliably separated. On the other hand, when the moving speed of the cutting point Pt of the workpiece W is changed, the cutting efficiency changes. Therefore, the moving speed of the cutting point Pt of the workpiece W is constant, and the peripheral speed of the outer peripheral surface of the annular tool 90 is changed. By setting the speed ratio to +1.0, the frictional work between the annular tool 90 and the workpiece W is minimized, and the effect of extending the tool life is obtained. Therefore, in the speed ratio fluctuation pattern described below, in principle, Speed ratio +1.0 is used as a reference.

The first variation pattern in which the speed ratio is constantly and constantly changed is a pattern in which the speed ratio is changed within a predetermined range of 0 or more, for example, as shown in FIG. 4A, the minimum speed ratio is 0, and the maximum speed ratio is +2. .0, and a pattern in which one cycle fluctuates in a sine wave shape of 2t.
The second variation pattern for constantly changing the speed ratio periodically is a pattern for changing the average speed ratio to be +1.0, for example, as shown in FIG. 4B, the minimum speed ratio is +0.3, the maximum speed is A pattern in which the ratio is changed to a sine wave with a ratio of +1.7 and a period of 2t is conceivable.
As a third variation pattern for constantly changing the speed ratio periodically, a pattern for changing the minimum speed ratio to be +1.0, for example, as shown in FIG. A pattern in which the ratio is changed to a sine wave with a ratio of +1.7 and a period of 2t is conceivable.

  In addition, as a variation pattern for keeping the speed ratio constant during a periodical change of the speed ratio without constantly changing the speed ratio, for example, as shown in FIG. A pattern in which the maximum speed ratio is fluctuated in a sine wave shape with a maximum speed ratio of +2.0 and one cycle of 0.5t, and the speed ratio is kept constant at +1.0 for the next predetermined time 3t can be considered. The time for keeping the speed ratio constant is set longer than the time for varying the speed ratio in order to improve the tool life. In this example, the sinusoidal variation is four periods, but a variation pattern having at least a half period of the sinusoidal variation may be used.

Further, as another variation pattern in which the speed ratio is periodically and constantly changed, the circular tool 90 is rotated forward and reverse at a constant cycle, for example, as shown in FIG. The pattern may be a sinusoidal pattern with a ratio of +2.0 and a period of 2t. In this example, in this case, the annular tool 90 is rotated forward and backward, but is stopped without rotating the annular tool 90 in the reverse direction, that is, the minimum speed ratio is 0, the maximum speed ratio is +2.0, and one cycle is 2t. May be changed in a sine wave pattern.
Note that the variation of the speed ratio in each pattern described above is sinusoidal, but may be triangular or rectangular.

Next, a method for obtaining a first variation pattern as a variation pattern of the speed ratio when the outer peripheral surface Ws of the cylindrical workpiece W is cut in the circumferential direction, that is, when the cutting is performed in the plunge direction feed, FIG. This will be described with reference to the flowchart of FIG.
The control device 80 acquires the tool diameter of the annular tool 90 (Step S1 in FIG. 3), and acquires the work diameter of the workpiece W (Step S2 in FIG. 3). Here, the tool diameter of the annular tool 90 is obtained by actually measuring with a measuring device. This tool diameter uses the diameter of the actually measured flank 91c (cutting edge 91r), that is, the diameter of the circumference perpendicular to the tool axis Rt passing through the cutting point Pt shown in FIG. 6B. The workpiece diameter of the workpiece W is the outer diameter of the workpiece W at the cutting point Pt, and is obtained from a design drawing or an NC program.

  Next, the control device 80 calculates the moving speed of the cutting point Pt of the workpiece W based on the acquired workpiece diameter of the workpiece W (Step S3 in FIG. 3). The moving speed v of the cutting point Pt of the workpiece W is the rotation speed of the cutting point Pt on the outer peripheral surface Ws of the workpiece W, and is expressed by the following formula (d) according to the workpiece diameter d of the workpiece W and the rotation speed n of the workpiece W. It is represented by 1).

  Next, based on the minimum speed ratio 0 and the maximum speed ratio 2.0 of the first variation pattern and the calculated moving speed of the cutting point Pt of the workpiece W, the control device 80 The minimum peripheral speed and the maximum peripheral speed are calculated (Step S4 in FIG. 3). The peripheral speed V of the annular tool 90 is the rotation speed of the cutting point Pt on the cutting edge 91r of the annular tool 90, and is expressed by the following equation (2) according to the speed ratio ν and the moving speed v of the cutting point Pt of the workpiece W. Is done.

  Next, the control device 80 varies sinusoidally based on the acquired tool diameter of the annular tool 90, the calculated minimum and maximum peripheral speeds of the outer peripheral surface of the annular tool 90, and one cycle of the first variation pattern. The rotation speed of the annular tool 90 to be performed is calculated (step S5 in FIG. 3). The rotation speed N of the annular tool 90 is expressed by the following equation (3) using the tool diameter D of the annular tool 90 and the peripheral speed V of the outer peripheral surface of the annular tool 90. As described above, a pattern in which the minimum speed ratio is +1.0, the maximum speed ratio is +2.0, and the period is 2t in a sine wave shape can be obtained in FIG. 4A.

  Next, a cutting method at the speed ratio of the first variation pattern using the annular tool 90 will be described with reference to the flowchart of FIG. 5 and the cutting state diagrams of FIGS. 6A, B-FIGS. The case where the outer peripheral surface Ws of the object W is cut in the circumferential direction will be described. In the initial state, it is assumed that the tilt table 60 is positioned so that the tool axis Rt of the annular tool 90 and the X axis are parallel.

  First, the control device 80 rotates (oscillates) the tilt base 60 around the tilt axis Rc to incline the tool axis Rt of the annular tool 90 (step S11 in FIG. 5). Specifically, the tilt control unit 84 controls the tilt motor 62 to rotate (swing) the tilt table 60 around the tilt axis Rc, and tilts the tool axis Rt of the annular tool 90 until the following state is reached. Let it. That is, a straight line Lt perpendicular to the rotation main axis Rw of the workpiece W and passing through the cutting point Pt on the outer peripheral surface Ws of the workpiece W is defined by a predetermined angle θ in the cutting direction G about the rotation main axis Rw of the workpiece W. The tool axis Rt of the annular tool 90 is inclined so as to be parallel to the obtained straight line Lc.

  Next, the control device 80 rotates the annular tool 90 in the rotation direction rt around the tool axis Rt based on the rotational speed of the annular tool 90 that fluctuates in a sine wave shape obtained in step S6 of FIG. W is rotated in the rotation direction rw around the rotation main axis Rw (step S12 in FIG. 5). Specifically, the tool rotation control unit 85 controls the tool motor 72 to rotate the annular tool 90 together with the tool spindle 71 so that the spindle rotation speed becomes the sine wave shape, and the spindle rotation control unit 81 By controlling the spindle motor 13, the rotating spindle 11 is driven to rotate at a constant rotation speed.

  Then, the control device 80 positions the cutting edge 91r of the annular tool 90 at the cutting point Pt on the outer peripheral surface Ws of the workpiece W (Step S13 in FIG. 5). Specifically, the carriage movement control unit 82 controls the Z-axis motor 22 to move the carriage 40 along the pair of Z-axis guide rails 21a and 21b. By controlling the motor 42 to move the feed base 50 along the pair of X-axis guide rails 41a and 41b, the cutting edge 91r of the annular tool 90 is positioned at the cutting point Pt on the outer peripheral surface Ws of the workpiece W.

  Then, the control device 80 moves the annular tool 90 in the X-axis direction with respect to the workpiece W to cut the outer peripheral surface Ws of the workpiece W in the circumferential direction (Step S14 in FIG. 3). Specifically, the feed base movement control unit 83 controls the X-axis motor 42 to move the feed base 50 along the pair of X-axis guide rails 41a and 41b, so that the workpiece W can be moved by the annular tool 90. The outer peripheral surface Ws is cut in the circumferential direction.

  In the above-described cutting, when the speed ratio between the peripheral speed of the outer peripheral surface of the tool main body 91 of the annular tool 90 and the moving speed of the cutting point Pt of the workpiece W reaches a maximum value and a minimum value, The outflow shape, outflow direction, outflow angle, and outflow speed of the chips vary greatly. Therefore, the chips are easily separated and flowed out at the timing when the speed ratio becomes the maximum value or the minimum value, and the chips do not become the continuous outflow of the connected chips as in the related art. There is no entanglement in W.

  More specifically, FIGS. 6A and 6B show the outflow state of the chips K1 when the speed ratio has the maximum value, and FIGS. 7A and B show the chips K2 when the speed ratio has changed from the maximum value to the minimum value. 8A and 8B show the outflow state of the chip K3 and the release state of the chip K2 when the speed ratio changes from the minimum value to the maximum value. .

  As is clear from FIGS. 6A and 6B and FIGS. 8A and 8B, the outflow shape of the chips K1, K2, and K3 indicates that the outflow shape of the chips K1 and K3 when the speed ratio has the maximum value has the minimum value of the speed ratio. As compared with the outflow shape of the chip K2 at the time of the cutting, the cutting amount of the cutting edge 91r with respect to the workpiece W is large, so that the width becomes wide. The outflow direction, the outflow angle and the outflow speed of the chips K1 and K3 when the speed ratio becomes the maximum value are compared with the outflow direction, the outflow angle and the outflow speed of the chip K2 when the speed ratio becomes the minimum value. However, when the speed ratio reached a minimum value, the gas flowed out at a relatively low speed in a direction substantially parallel to the X-axis, whereas the speed ratio reached a maximum value because the portion in contact with the rake face 91b was large. At this time, it flows out at a relatively high speed in a direction inclined toward the rake face 91b with respect to the X axis. Therefore, the chips K1, K2, and K3 are separated at the timing when the speed ratio becomes the maximum value or the minimum value.

  Then, the control device 80 determines whether or not the cutting has been completed (step S15 in FIG. 5). If it is determined that the cutting has not been completed, the cutting is continued. On the other hand, when it is determined that the cutting has been completed, it is determined whether or not the next workpiece W exists (step S16 in FIG. 5). When it is determined that the next workpiece W exists, the current workpiece W is referred to as the next workpiece W. It exchanges (step S17 of FIG. 5), returns to step S11, and repeats the above processing. On the other hand, when it is determined that there is no next workpiece W, the rotation of the annular tool is stopped (step S18 in FIG. 5), and all the processes are ended.

  In addition, in the annular tool 90, a cutting action is shown in which the rake face 91b of the tool main body 91 cuts into the outer circumferential face Ws of the workpiece W while rotating. For this reason, the cutting resistance can be reduced by the pulling action and the temperature of the cutting edge 91r can be reduced, so that the tool life of the annular tool 90 can be improved. Therefore, in the cutting using the annular tool 90, more efficient cutting can be performed in cutting of difficult-to-cut materials such as titanium alloy and inconel in which the temperature of the cutting edge 91r is a problem.

(4. Others)
In the above-described embodiment, the peripheral speed of the outer peripheral surface of the tool main body 91 of the annular tool 90 is the peripheral speed of the cutting edge 91r formed by the rake face 91b and the flank 91c of the annular tool 90. The peripheral speed at the intermediate portion of the cutting tool 90 in the direction of the tool axis Rt on the surface 91b or the average peripheral speed over the entire rake face 91b may be used. Alternatively, the average peripheral speed of a part or a part of the rake face 91b other than the intermediate part of the cutting tool 90 in the direction of the tool axis Rt (for example, only the area in contact with the chip K) may be used. Also, the area of the rake face 91b targeted for the average peripheral velocity may be the outer peripheral face including the cutting edge 91r, or the cutting edge 91r may be treated separately from the area of the rake face 91b, and may not be the target of the average peripheral velocity. Is also good.

The tool diameter of the annular tool 90 is the diameter of the actually measured flank 91c (cutting edge 91r), but may be the diameter of the actually measured rake face 91b at the intermediate portion of the contact length between the cutting edge 91r and the chip K. .
Although the tool body 91 of the annular tool 90 is formed in a truncated cone shape, the cross section perpendicular to the axis may be circular, and for example, may be formed in a columnar shape or an inverted truncated cone shape. In this case, if the rake face is positive, the flank may interfere with the workpiece W. Therefore, the rake face may be negative or the flank may be recessed to reduce interference with the workpiece W. To prevent.

  In the above-described embodiment, the case where the outer peripheral surface Ws of the cylindrical workpiece W is cut in the circumferential direction, that is, the processing in the X (plunge) direction feed has been described, but the processing in the Z (traverse) direction feed. The same is true for That is, as shown in FIGS. 9A and 9B, the tool axis Rt of the annular tool 90 is set so as to be inclined by a predetermined angle θ in the cutting feed direction Gt from a state parallel to the normal to the cutting point Pt. Then, the rake face 91b of the annular tool 90 is rotated about the tool axis Rt in the rotation direction rt, and the workpiece W is rotated about the rotation axis Rw in the rotation direction rt. The outer peripheral surface Ws of the workpiece W is cut by feeding the workpiece W in a direction parallel to the rotation axis Rw, or by feeding the workpiece W in a direction parallel to the rotation axis Rw without feeding the annular tool 90.

  In the above-described embodiment, the cylindrical grinding has been described as an example. However, the annular tool 90 can be applied to surface grinding. That is, as shown in FIG. 10A and FIG. 10B, the tool axis Rt of the annular tool 90 is set so as to be inclined at a predetermined angle θ in the cutting feed direction GG from a state perpendicular to the upper plane WWs of the workpiece WW. I do. Then, the rake face 91b of the annular tool 90 is rotated in the rotation direction rt around the tool axis Rt, and the annular tool 90 is moved along the upper plane WWs of the workpiece WW, or the annular tool 90 is moved. Without moving the workpiece WW in a direction parallel to the upper plane WWs, the upper plane WWs of the workpiece WW is cut.

(5. Effect)
The cutting device 1 of the present embodiment includes an annular tool 90 having an annular cutting edge 91r, a tool spindle 71 for attaching the annular tool 90, and rotating the annular tool 90 around a tool axis Rt of the annular tool 90, and a workpiece. A rotary spindle 11 (work holding table) for holding W, and a control device 80 for controlling the relative position between the tool spindle 71 and the rotating spindle 11 (work holding table) and the rotation of the tool spindle 71 are provided. Then, the control device 80 arranges the tool spindle 71 and the rotary spindle 11 (work holding table) in a relative positional relationship in which the outer peripheral surface of the annular tool 90 becomes the rake face 91b and the end face of the annular tool 90 becomes the flank 90c. The workpiece W is machined by the annular tool 90 while changing the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool 90 and the moving speed of the workpiece W at the cutting point Pt.

  In the cutting by the annular tool 90, since the outflow shape, the outflow direction, the outflow angle, and the outflow speed of the chips K1, K2, and K3 are changed by changing the speed ratio during the cutting, the chips K1, K2, and K3 are changed. Is cut off, and the chips can be prevented from becoming entangled with the tool spindle 71 and the workpiece W.

  Further, the control device 80 changes the peripheral speed of the outer peripheral surface of the annular tool 90, and makes the annular tool 90 machine the workpiece W while changing the speed ratio while keeping the moving speed of the cutting point Pt of the workpiece W constant. Do. By changing the peripheral speed of the outer peripheral surface of the annular tool 90, more reliably at the timing at which the force for pulling the chips K1, K2, and K3 by the annular tool 90 increases when increasing the peripheral speed of the outer peripheral surface of the annular tool 90. The chips K1, K2, K3 can be cut. Further, when the moving speed of the cutting point Pt of the workpiece W is changed, the cutting efficiency changes, but when the peripheral speed of the outer peripheral surface of the annular tool 90 is changed, a stable cutting efficiency is obtained. Can be

Further, since the control device 80 processes the workpiece W with the annular tool 90 while periodically changing the speed ratio, the cutting process control becomes easier as compared with the case where the speed ratio is changed irregularly.
Further, since the control device 80 processes the workpiece W with the annular tool 90 while constantly changing the speed ratio, it is possible to prevent continuous outflow of connected chips.
The control device 80 alternately performs processing of the workpiece W with the annular tool 90 while changing the speed ratio, and processing of the workpiece W with the annular tool 90 while keeping the speed ratio constant. Therefore, the chips K1, K2, and K3 can be cut at a desired length.
Further, the control device 80 makes the time for keeping the speed ratio constant longer than the time for keeping the speed ratio varied, so that the tool life can be improved.

Further, since the control device 80 processes the workpiece W with the annular tool 90 while changing the speed ratio so that the speed ratio becomes 0 or more, the chips K1, K2, and K3 are removed from the tool body 91 of the annular tool 90. Is separated by being pulled by the outer peripheral surface.
Further, the control device processes the workpiece with the annular tool while changing the speed ratio so that the minimum speed ratio at the time of the change of the speed ratio is 1.0 or more. Friction work can be reduced, and the tool life extension effect can be obtained.

Further, since the control device 80 processes the workpiece W with the annular tool 90 so that the rotation direction of the annular tool 90 becomes forward and reverse rotation, the chips K1, K2, and K3 can be separated when the rotation direction changes.
Further, the control device 80 processes the workpiece W with the annular tool 90 while changing the speed ratio so that the absolute value of the average speed ratio when the speed ratio changes becomes 1.0. Friction work with the workpiece W is minimized, and an effect of extending tool life is obtained.

  The cutting method according to the present embodiment includes an annular tool 90 having an annular cutting edge 91r, a tool spindle 71 for attaching the annular tool 90, rotating the annular tool 90 around the tool axis Rt of the annular tool 90, and a workpiece. A cutting method of a cutting device 1 comprising: a rotating spindle 11 (a workpiece holding table) for holding the tool spindle 71 and the rotating spindle 11 (a workpiece holding table); And the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool 90 and the moving speed of the cutting point Pt of the workpiece W is varied by arranging the relative position where the end face of the annular tool 90 becomes the flank 91c. And a processing step of processing the workpiece W with the annular tool 90. According to the cutting method of the present embodiment, the same effects as those of the above-described cutting device 1 can be obtained.

  1: cutting device, 7: rotating spindle, 71: tool spindle, 80: control device, 90: annular tool, 91b: rake face, 91c: flank face, 91r: cutting edge, W: workpiece

Claims (16)

An annular tool having an annular cutting edge,
A tool spindle for attaching the annular tool and rotating the annular tool around the axis of the annular tool,
A workpiece holder for holding the workpiece,
A control device for controlling the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle,
With
The control device includes:
The tool spindle and the workpiece holding table are arranged in a relative positional relationship such that an outer peripheral surface of the annular tool is a rake surface, and an end surface of the annular tool is a flank,
And performing the machining of the annular tool with the workpiece while changing the speed ratio so that the speed ratio of the moving speed of the cutting point of peripheral speed between the workpiece outer circumferential surface is 0 or more of the annular tool A cutting device that alternately performs the processing of the workpiece with the annular tool while keeping the speed ratio constant . 2. The cutting device according to claim 1 , wherein the control device makes a time for keeping the speed ratio constant longer than a time for keeping the speed ratio varied. 3. Wherein the control device performs processing of the workpiece with the annular tool while changing the speed ratio so that the absolute value of the average speed ratio during the fluctuation of the speed ratio is 1.0, according to claim 1 or 2 3. The cutting device according to claim 1. An annular tool having an annular cutting edge,
  A tool spindle for attaching the annular tool and rotating the annular tool around the axis of the annular tool,
  A workpiece holder for holding the workpiece,
  A control device for controlling the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle,
  With
  The control device includes:
  The tool spindle and the workpiece holding table are arranged in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface, and an end surface of the annular tool is a flank,
  While changing the speed ratio such that the absolute value of the average speed ratio when the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece changes becomes 1.0, the annular speed is changed. A cutting device for processing the workpiece with a tool. The cutting device according to claim 4 , wherein the control device performs the machining of the workpiece with the annular tool while constantly changing the speed ratio. The cutting device according to any one of claims 1 to 5, wherein the control device performs the processing of the workpiece with the annular tool while changing the speed ratio in a state where the annular tool is rotated in one direction. . The control device varies the peripheral speed of the outer peripheral surface of the annular tool, makes the moving speed of the cutting point of the workpiece constant, and processes the workpiece with the annular tool while varying the speed ratio. The cutting device according to any one of claims 1 to 6 . The cutting device according to any one of claims 1 to 7, wherein the control device performs the machining of the workpiece with the annular tool while periodically varying the speed ratio. An annular tool having an annular cutting edge,
A tool spindle for attaching the annular tool and rotating the annular tool around the axis of the annular tool,
A workpiece holder for holding the workpiece,
A control device for controlling the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle,
With
The control device includes:
The tool spindle and the workpiece holding table are arranged in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface, and an end surface of the annular tool is a flank,
Machining the workpiece with the annular tool while varying the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece; and maintaining the annular speed while keeping the speed ratio constant. A cutting device that alternately performs processing of the workpiece with a tool. The cutting device according to claim 9 , wherein the control device makes a time for keeping the speed ratio constant longer than a time for keeping the speed ratio varied. An annular tool having an annular cutting edge,
A tool spindle for attaching the annular tool and rotating the annular tool around the axis of the annular tool,
A workpiece holder for holding the workpiece,
A control device for controlling the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle,
With
The control device includes:
The tool spindle and the workpiece holding table are arranged in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface, and an end surface of the annular tool is a flank,
The minimum speed ratio when the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece changes is 1. A cutting device for machining the workpiece with the annular tool while changing the speed ratio to be zero . An annular tool having an annular cutting edge,
A tool spindle for attaching the annular tool and rotating the annular tool around the axis of the annular tool,
A work holding table for holding the work,
A control device for controlling the relative position of the tool spindle and the workpiece holding table and the rotation of the tool spindle,
With
The control device includes:
The tool spindle and the workpiece holding table are arranged in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface, and an end surface of the annular tool is a flank,
While changing the speed ratio so that the absolute value of the average speed ratio at the time of the change of the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece becomes 1.0, A cutting device for processing the workpiece with a tool. Cutting of a cutting device comprising: an annular tool having an annular cutting edge, a tool spindle for attaching the annular tool, rotating the annular tool around the axis of the annular tool, and a work holding table for holding the work. The method
An arranging step of arranging the tool spindle and the workpiece holding table in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface and an end surface of the annular tool is a flank;
And performing the machining of the annular tool with the workpiece while changing the speed ratio so that the speed ratio of the moving speed of the cutting point of peripheral speed between the workpiece outer circumferential surface is 0 or more of the annular tool Performing the machining of the workpiece with the annular tool while keeping the speed ratio constant ;
A cutting method comprising: Cutting of a cutting device comprising: an annular tool having an annular cutting edge; a tool spindle for attaching the annular tool, rotating the annular tool around an axis of the annular tool; and a work holding table for holding a work. The method
  An arranging step of arranging the tool spindle and the workpiece holding table in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface and an end surface of the annular tool is a flank;
  Performing the machining of the workpiece with the annular tool while changing the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece; Machining the workpiece with a tool, a machining step to alternately perform,
A cutting method comprising: Cutting of a cutting device comprising: an annular tool having an annular cutting edge, a tool spindle for attaching the annular tool, rotating the annular tool around the axis of the annular tool, and a work holding table for holding the work. The method
  An arranging step of arranging the tool spindle and the workpiece holding table in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface and an end surface of the annular tool is a flank;
  While changing the speed ratio so that the minimum speed ratio at the time of the change of the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece is 1.0, A machining process for machining the workpiece,
A cutting method comprising: Cutting of a cutting device comprising: an annular tool having an annular cutting edge; a tool spindle for attaching the annular tool, rotating the annular tool around an axis of the annular tool; and a work holding table for holding a work. The method
  An arranging step of arranging the tool spindle and the workpiece holding table in a relative positional relationship in which an outer peripheral surface of the annular tool is a rake surface and an end surface of the annular tool is a flank;
  While changing the speed ratio such that the absolute value of the average speed ratio when the speed ratio between the peripheral speed of the outer peripheral surface of the annular tool and the moving speed of the cutting point of the workpiece changes becomes 1.0, the annular speed is changed. A processing step of processing the workpiece with a tool,
A cutting method comprising:

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