JP2004122261A - Deviation detecting device and method of cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely detect deviation of a cutting tool. <P>SOLUTION: This device for detecting the deviation of the cutting tool T rotating by attached to a rotary shaft is provided with an elastically deformable first contact piece P1 and an elastically deformable second contact piece P2 being in parallel to the first contact piece P1 and disposed in a position separated therefrom by a prescribed value L. The cutting tool T is so positioned as to approximately orthogonally cross with a plane passing between the two contact pieces P1 and P2 and including the two contact pieces P1 and P2 and to set the rotary axis of the rotary shaft on the central line of the two contact pieces. When the positioned cutting tool T rotates around the axis, whether the outer circumference of the cutting tool T and the two contact pieces P1 and P2 are contacted or not is detected. In this device, the interval between the two contact pieces P1 and P2 is set to a prescribed value and it is detected whether the cutting tool T contacts with the two contact pieces P1 and P2 or not, so that the deviation of the cutting tool T can be detected highly precisely. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting run-out of a cutting tool which is mounted on a rotating shaft and rotates.
[0002]
2. Description of the Related Art As an apparatus for detecting run-out of a cutting tool, for example, an apparatus described in Japanese Patent Application Laid-Open No. 2-243252 is known.
The device described in the above publication includes a contact that comes into contact with the outer periphery of the cutting tool and moves up and down in accordance with the run-out of the cutting tool, and a unit that outputs an electric signal corresponding to the position of the contact in the vertical direction. In order to detect the run-out of the cutting tool by this device, first, the cutting tool is rotated at least one time around the axis, and an electric signal output from the detection device is taken in the meantime. Next, the run-out amount of the contact (that is, the cutting tool) is calculated from the maximum value and the minimum value of the captured electric signal.
[0003]
[Patent Document 1]
JP-A-2-243252
[0004]
In the above-described conventional apparatus, the vertical movement of the contact (running of the cutting tool) is converted into an electric signal, and the runout of the cutting tool is calculated from the converted electric signal. I do. For this reason, there is a problem that an error is likely to occur when the deflection of the cutting tool is converted into an electric signal and the detection accuracy is low.
[0005]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to realize a technique capable of accurately detecting the runout of a cutting tool.
[0006]
A first detecting device according to the present invention created to solve the above-mentioned problem detects a run-out of a cutting tool which is attached to a rotating shaft and rotates. An elastically deformable first contact piece, and an elastically deformable elastically disposed at a position parallel to the first contact piece and separated by a value obtained by subtracting a predetermined value from the outer diameter of the cutting tool. A possible second contact piece, the cutting tool passing between the two contact pieces and being substantially perpendicular to the plane containing the two contact pieces, and the rotation axis of the rotation axis being on the center line of the two contact pieces; It has means for positioning the cutting tool so that the cutting tool rotates around the axis, and means for detecting whether or not the outer periphery of the cutting tool is in contact with the two contact pieces.
In the detection device, the cutting tool is positioned between the two contact pieces and substantially perpendicular to a plane including the two contact pieces, and when the positioned cutting tool rotates, the cutting tool and the cutting tool are rotated during the rotation. It is detected whether the two contact pieces are in contact with each other. Since the two contact pieces are disposed apart from each other by a distance obtained by subtracting a predetermined value from the outer diameter of the cutting tool, when the deflection of the cutting tool is within a predetermined amount (（of the predetermined value), the two contact pieces are arranged. The cutting tool comes into contact with the cutting tool, and when the deflection of the cutting tool exceeds a predetermined amount (（of the predetermined value), the cutting tool contacts only one contact piece. Therefore, by detecting the presence or absence of contact between the cutting tool and the two contact pieces while the cutting tool rotates around the axis, it is possible to detect whether the run-out of the cutting tool has exceeded a predetermined amount.
In the detection device, two contact pieces are arranged in advance at a predetermined interval, and only whether or not the cutting tool is in contact with the two contact pieces is detected. Therefore, it is possible to accurately detect whether or not the run-out of the cutting tool has exceeded a predetermined amount.
[0007]
In the detection device, various means can be employed as means for detecting whether the cutting tool is in contact with the two contact pieces. For example, the following configuration can be employed. That is, the cutting tool and the two contact pieces are formed of a conductor, and a predetermined voltage is applied to one of the two contact pieces, while the other is grounded. Is detected.
In such a configuration, when the cutting tool is in contact with the two contact pieces, the two contact pieces are energized, and when the cutting tool is not in contact with the two contact pieces, the two contact pieces are de-energized. Therefore, by detecting the energization / de-energization of the two contact pieces, it is possible to detect the presence or absence of contact between the cutting tool and the two contact pieces.
[0008]
Further, it is preferable that the outer peripheral surface of the cutting tool is insulated except for a predetermined angle range set in the deflection detection direction.
According to such a configuration, the two contact pieces are energized only when they come into contact with the two contact pieces within a predetermined angle range set in the runout detection direction on the outer peripheral surface of the cutting tool, and the power is applied outside the predetermined angle range. Even when the two contact pieces make contact with each other, the two contact pieces do not conduct electricity. For this reason, it is possible to detect only the touch of the cutting tool in a specific direction.
[0009]
Further, in the above detection device, the interval between the two contact pieces is a distance obtained by subtracting twice the allowable run-out value from the outer diameter of the cutting tool, and the cutting tool positioned by the positioning means makes at least one rotation around the axis. It is preferable to further include a unit that determines whether or not the run-out of the cutting tool exceeds a run-out allowable value based on a contact state between the cutting tool and the two contact pieces detected by the detecting unit.
According to such a configuration, since the interval between the two contact pieces is determined in consideration of the runout tolerance (for example, determined from the processing tolerance), the cutting tool depends on the contact state between the cutting tool and the two contact pieces. It is possible to determine whether or not the shake of the data exceeds an allowable value.
[0010]
Further, in the detection device, the positioning means moves the cutting tool such that the rotation axis of the rotation shaft moves on an inclined line intersecting a center line of the two contact pieces in a plane including the two contact pieces. Preferably.
According to such a configuration, even if an error is included in the positioning by the positioning means, the trajectory of the rotation axis of the rotating shaft intersects with the center line of the two contact pieces, so that the rotating axis of the rotating shaft is It can be located on the center line of the contact piece.
[0011]
When the trajectory of the rotation axis of the rotation axis intersects the center line of the two contact pieces as described above, it is preferable to detect the runout of the cutting tool by the method described below.
That is, an elastically deformable first contact piece and an elastically deformable first contact piece which are arranged in parallel with the first contact piece and separated by a value obtained by subtracting a predetermined value from the outer diameter of the cutting tool. A method for detecting runout of a rotating cutting tool attached to a rotating shaft using the two contact pieces, wherein the cutting tool passes between the two contact pieces and is substantially on a plane including the two contact pieces. Positioning the cutting tool so that the rotation axis of the rotation axis is located at a predetermined position on an inclined line that is orthogonal and intersects the center line of the two contact pieces in a plane including the two contact pieces; Rotating the positioned cutting tool at least one rotation about the axis, and detecting whether the outer periphery of the cutting tool is in contact with the two contact pieces during one rotation of the cutting tool, By repeatedly executing the positioning process, The axis of rotation of the shaft is moved by the inclined line, wherein executing the detection step for each position positioned by the positioning step.
In the above-described detection method, the cutting tool is moved such that the rotation axis of the rotation shaft moves on the inclined line, and it is detected whether the cutting tool and the two contact pieces are in contact at each position. Therefore, the rotation axis of the rotation shaft is located on the center line of the two contact pieces at any position, and the presence or absence of contact between the cutting tool and the two contact pieces at that position is detected.
[0012]
Further, a second detecting device according to the present invention created to solve the above-described problem is a device which is attached to a rotating shaft and detects run-out of a rotating cutting tool, and includes a contact piece which is elastically deformable. Means for positioning the cutting tool such that the distance from the rotation axis of the rotating shaft to the contact piece is a predetermined value, and when the cutting tool rotates around the axis, the outer periphery of the cutting tool contacts the contact piece. Means for detecting whether or not the operation is performed.
In this detection device, the cutting tool is positioned at a position away from the contact piece by a predetermined distance, and the presence or absence of contact between the cutting tool and the contact piece when the positioned cutting tool rotates around the axis is detected. . Therefore, by variously changing the distance between the cutting tool and the contact piece, it is possible to detect whether or not the runout of the cutting tool is within an allowable value, the runout amount of the cutting tool, and the like.
For example, the cutting tool is positioned such that the distance from the axis of rotation of the rotating shaft to the contact piece is a distance obtained by subtracting the allowable run-out value from the radius of the cutting tool. In this case, when the run-out of the cutting tool is within the allowable run-out value, the cutting tool and the contact piece come into contact with each other, and when the run-out of the cutting tool exceeds the allowable run-out value, the cutting tool and the contact piece do not come into contact with each other. Therefore, based on the state of contact between the cutting tool and the contact piece detected by the detection means while the cutting tool positioned as described above makes at least one rotation about the axis, the deflection of the cutting tool is within an allowable value. It can be determined whether or not there is. Alternatively, the presence or absence of contact between the cutting tool and the contact piece is detected while moving the cutting tool toward the contact piece, and the position at which the cutting tool and the contact piece start contacting and the position at which the cutting tool and the contact piece always contact are determined. Ask. Then, the run-out amount of the cutting tool can be obtained from these two positions.
Even with this detection device, it is possible to accurately detect the run-out of the cutting tool because it detects only whether the cutting tool is in contact with the contact piece.
[0013]
In the second detection device, the cutting tool and the contact piece are formed of a conductor, and a predetermined voltage is applied to one of the cutting tool and the contact piece, while the other is grounded. Preferably, the means detects whether or not the cutting tool and the contact piece are in contact with each other based on whether or not the cutting tool and the contact piece are energized.
Further, like the first detection device, it is preferable that the outer peripheral surface of the cutting tool is insulated except for a predetermined angle range set in the deflection detection direction.
[0014]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shake detecting device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the principle of detecting runout of a cutting tool using the runout detection device of the first embodiment.
As shown in FIG. 1, the shake detection device according to the first embodiment includes two spring pins P1 and P2. The spring pins P1 and P2 are arranged parallel to each other and spaced by a predetermined value L (<outer diameter D of the cutting tool). One end A1 of the spring pin P1 is fixed, and one end A2 of the spring pin P2 is fixed. The spring pins P1 and P2 are formed of an elastically deformable material. For this reason, when an external force acts on the spring pins P1 and P2, the spring pins P1 and P2 are elastically deformed and bent (see FIGS. 3B and 3C). The spring pins P1 and P2 are not particularly limited as long as they are elastically deformable materials, but are formed of a conductive material (for example, a metal material) in the present embodiment.
The cutting tool T is a cutting tool such as an end mill or a drill (a cross section is shown in FIG. 1). The cutting tool T is mounted on a rotating shaft not shown. Therefore, when the rotating shaft rotates, the cutting tool T also rotates. The rotating cutting tool T is brought into contact with a workpiece (not shown), whereby the workpiece is cut. Further, the rotating shaft to which the cutting tool T is attached can be positioned by a positioning mechanism not shown.
The mounting structure of the cutting tool T to the rotating shaft can be performed, for example, by providing a fitting hole at the tip of the rotating shaft and fitting the base of the cutting tool T into the fitting hole. If the cutting tool T is mounted on the rotating shaft with foreign matter such as chips attached to the base of the cutting tool T or the fitting hole of the rotating shaft, the cutting tool swings around the rotation axis of the rotating shaft. Note that the cutting tool T is also formed of a conductive material (for example, a metal material).
[0015]
In order to detect the run-out of the cutting tool T by using the above-mentioned spring pins P1 and P2, the cutting tool T passes between the spring pins P1 and P2 as shown in FIGS. The cutting tool T is positioned so as to be substantially perpendicular to the plane including the pins P1 and P2 and to have the rotation axis of the rotation axis on the center line of the two spring pins P1 and P2. Here, FIG. 1 (b) shows a state where the cutting tool T does not run out, and FIG. 1 (c) shows a state where the cutting tool T runs out.
As shown in FIG. 1B, when the cutting tool T does not swing, the rotation axis of the rotating shaft and the axis C of the cutting tool T are aligned. Therefore, the outer periphery of the cutting tool T comes into contact with the spring pins P1 and P2.
On the other hand, as shown in FIG. 1 (c), when the cutting tool T is oscillating, the rotation axis of the rotary shaft and the axis C of the cutting tool T are displaced, and the axis C of the cutting tool T is shifted from the spring pins P1 and P2. The position is shifted from the center line of. Therefore, the cutting tool T approaches one spring pin and separates from the other spring pin. In the state shown in FIG. 1C, the cutting tool T is shifted in the direction of the spring pin P1 by (DL) / 2. When the cutting tool T further deviates from the state shown in FIG. 1 (c) in the direction of the spring pin P1, the cutting tool T and the spring pin P2 do not come into contact with each other. That is, when the cutting tool T swings beyond (DL) / 2, the cutting tool T and the two spring pins P1 and P2 do not come into contact with each other. In other words, the cutting tool T and the two spring pins P1 and P2 come into contact with each other within a range not exceeding (DL) / 2 even if the cutting tool T oscillates. Therefore, in the first embodiment, it is determined whether or not the cutting tool T is in contact with the two spring pins P1 and P2 when the cutting tool T rotates around the axis (that is, the rotation axis rotates). Thus, it is detected whether the deflection of the cutting tool T exceeds (DL) / 2.
As is clear from the above, it is determined whether the runout of the cutting tool T exceeds the runout allowable value Pb by determining the interval L between the spring pins P1 and P2 based on the runout allowable value Pb of the cutting tool T. It is possible to do. Specifically, it is obtained by solving Pb = (DL) / 2. That is, the interval L between the spring pins P1 and P2 is D (diameter of the cutting tool T) −2 × Pb (permissible runout).
The allowable runout value Pb can be appropriately determined by a designer, and can be determined based on, for example, a processing tolerance required for a workpiece processed by the cutting tool T.
[0016]
Whether or not the cutting tool T is in contact with the spring pins P1 and P2 is detected based on whether or not electricity is supplied between the spring pins P1 and P2.
Specifically, a voltage V is applied to the spring pin P1 as shown in FIG. 2A, and the spring pin P2 is grounded as shown in FIG. 2B. As described above, the cutting tool T and the spring pins P1 and P2 of the first embodiment are formed of a conductor. Therefore, when the cutting tool T contacts the spring pins P1 and P2, the spring pin P1 is grounded via the cutting tool T, so that the voltage of the spring pin P1 becomes 0V. On the other hand, if the cutting tool T is not in contact with the spring pins P1 and P2, the spring pin P1 is not grounded. Therefore, it is possible to detect whether the cutting tool T is in contact with the spring pins P1 and P2 based on the voltage of the spring pin P1. The detection of whether or not the current flows between the spring pins P1 and P2 can be performed by detecting whether or not a current has flowed between the spring pins P1 and P2 in addition to monitoring the voltage of the spring pin P1. it can.
FIGS. 2C and 2D illustrate voltage changes of the spring pin P1 when the cutting tool T makes one rotation around the axis. When the voltage changes as shown in FIG. 2C, it can be determined that the cutting tool T and the spring pins P1 and P2 are always in contact while the cutting tool T rotates around the axis. When the voltage changes as shown in FIG. 2D, it is determined that the cutting tool T and the spring pins P1 and P2 are temporarily in a non-contact state while the cutting tool T rotates around the axis. be able to.
[0017]
Note that the direction in which the cutting tool T swings changes according to the state of attachment of the cutting tool T to the rotating shaft. FIG. 3 schematically shows the relationship between the deflection direction of the cutting tool T and the processing surface of the workpiece. In FIG. 3, a cutting tool T is constituted by a main body M and a blade B which is in contact with a workpiece.
FIG. 3A shows a state in which no run-out has occurred in the cutting tool T. In a state in which no run-out has occurred in the cutting tool T, the axis of the cutting tool T coincides with the rotation axis of the rotating shaft. Accordingly, the cutting edge trajectory D is a circle centered on the axis of the cutting tool T, and the distance between the processing surface of the workpiece and the rotation axis of the rotating shaft (the axis of the cutting tool T) is determined from the axis of the cutting tool T. This corresponds to the distance to the tip of the blade B. Therefore, the workpiece is cut accurately.
FIG. 3B shows a state in which the cutting tool T swings in the tooth tip direction. In the figure, a solid line indicates a state where the cutting tool T does not swing, and a two-dot chain line indicates a state where the cutting tool T swings in the direction of the cutting edge. In the state shown in FIG. 3B, the axis of the cutting tool T is shifted in the direction of the cutting edge with respect to the rotation axis of the rotation shaft. Since the cutting edge locus is a circle centered on the rotation axis of the rotation axis, the distance between the processing surface of the workpiece and the rotation axis of the rotation axis coincides with the distance from the axis of the cutting tool T to the tip of the blade B. Disappears. Therefore, the machined surface S1 when there is no runout is different from the machined surface S2 when there is runout, and the workpiece is not cut accurately.
FIG. 3C shows a state in which the cutting tool T oscillates in a direction orthogonal to the tooth tip direction. In the drawing, a solid line indicates a state in which the cutting tool T does not swing, and a two-dot chain line indicates a state in which the cutting tool T swings in a direction orthogonal to the cutting edge direction. In the state shown in FIG. 3C, the axis of the cutting tool T is shifted in a direction orthogonal to the direction of the cutting edge with respect to the rotation axis of the rotation shaft. The cutting edge trajectory is a circle centered on the rotation axis of the rotating shaft (that is, a circle whose radius is the distance from the rotating axis to the cutting edge). Is approximately equal to the distance from the axis of the cutting tool T to the tip of the blade B. Therefore, the processing surface S3 when there is a runout substantially matches the case where there is no runout, and the workpiece is cut almost accurately.
[0018]
As is clear from the above, when the cutting tool T oscillates in the direction of the cutting edge, the machining accuracy of the workpiece is greatly affected. Even when the cutting tool T oscillates in a direction perpendicular to the direction of the cutting edge, the processing accuracy of the workpiece is reduced. Does not affect much. Therefore, in order to evaluate the run-out of the cutting tool T from the viewpoint of machining accuracy, it is preferable to detect only the run-out of the cutting tool T in the cutting edge direction.
In order to detect only run-out in the direction of the cutting edge, for example, it is preferable that the cutting tool T has a structure as shown in FIG. In the cutting tool T shown in FIG. 4, the insulator 12 is arranged on a part of the outer periphery, and only the outer periphery 14a, 14b in the direction of the cutting edge is not insulated. Therefore, only when the outer circumferences 14a and 14b in the blade edge direction come into contact with the spring pins P1 and P2, the spring pin P1 conducts electricity with the spring pin P2 via the conductive portion 10 of the cutting tool T. This makes it possible to detect only the runout of the cutting tool T in the direction of the cutting edge.
FIG. 5 shows a change with time of the voltage of the spring pin P1 when a run-out (run-out is within an allowable value) of the cutting tool is detected using the cutting tool shown in FIG. The cutting tool T is energized only when it comes into contact with the spring pins P1 and P2 at the outer circumferences 14a and 14b in the direction of the cutting edge. The voltage of P1 is 0V. Therefore, if a signal as shown in FIG. 5 is detected, it can be determined that the run-out of the cutting tool T in the cutting edge direction is within the allowable value.
[0019]
Further, when the detection accuracy of the above-described detection device is more required, it is necessary to accurately position the rotation axis of the rotation shaft on which the cutting tool T is mounted on the center lines of the spring pins P1 and P2. For this purpose, as shown in FIG. 6, it is preferable to move the cutting tool so that the rotation axis of the rotation shaft moves on an inclined line inclined with respect to the spring pins P1 and P2. That is, if the positioning accuracy of the rotating shaft is low, the locus of the rotating axis of the rotating shaft varies. However, since the locus of the rotation axis of the rotating shaft is inclined with respect to the spring pins P1 and P2, the locus of the rotating axis of the rotating shaft always intersects with the center lines of the spring pins P1 and P2. For this reason, the rotation axis of the rotating shaft can be passed on the center line of the spring pins P1 and P2 by appropriately determining the inclination angle with respect to the spring pins P1 and P2.
In the case where the rotation axis of the rotation shaft is inclined and moved to the spring pins P1 and P2, it is not always necessary to specify which position during the movement is on the center line of the spring pins P1 and P2. That is, the presence or absence of contact with the spring pins P1 and P2 when the cutting tool T makes one rotation around the axis while moving the rotation axis of the rotation axis is detected, and the cutting tool T is moved at any point on the movement locus. If the run-out is within the allowable range, it is determined that the run-out of the cutting tool is within the allowable range. If the run-out of the cutting tool T exceeds the allowable range at all points on the movement path, the run-out of the cutting tool T is allowed. What is necessary is just to determine that it exceeds the value.
[0020]
Second Embodiment A shake detection device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 7 shows the principle of detecting the run-out of the cutting tool by the run-out detection device of the second embodiment.
As shown in FIG. 7, unlike the first embodiment, the shake detection device of the second embodiment includes only one spring pin P3. The spring pin P3 is also similar to the spring pins P1 and P2 of the first embodiment in that one end A3 of the spring pin P3 is fixed, and that the spring pin P3 is formed of an elastically deformable and conductive material. It is.
[0021]
In order to detect the run-out of the cutting tool T using the spring pin P3, as shown in FIG. 7A, the rotation axis (that is, the rotation axis of the rotation axis) is shifted from the reference position by the distance L1 in the direction of the spring pin P3. The cutting tool T is moved (FIG. 7A shows a case where the rotation axis of the rotation shaft coincides with the rotation axis C of the cutting tool T). As shown in FIGS. 7B and 7C, the distance L2 between the reference position and the spring pin P3 is set in advance. Therefore, when the rotation axis moves by the distance L1 from the reference position in the direction of the spring pin P3, the distance between the rotation axis of the rotation axis and the spring pin P3 becomes L2-L1. Therefore, by appropriately setting the distances L2 and L1, it is possible to detect the run-out of the cutting tool T.
[0022]
For example, L2-L1 is a value obtained by subtracting the run-out allowable value Pb from the radius D / 2 of the cutting tool T (that is, L2-L1 = D / 2-Pb). FIG. 7B shows the relationship between the cutting tool T and the spring pin P3 when the cutting tool T has runout in such a case, and shows the relationship between the cutting tool T and the spring pin P3 when the cutting tool T has no runout. Is shown in FIG. 7 (c).
In FIG. 7B, since the run-out occurs in the cutting tool T, the distance between the axis C of the cutting tool T and the reference position is not L1, but L3 (<L1). As is clear from the drawing, when L2−L3> D / 2, the cutting tool T and the spring pin P3 do not come into contact with each other. Here, since the run-out H of the cutting tool is L1-L3, the above equation is L2- (L1-H)> D / 2.
H> D / 2− (L2−L1) = Pb
Accordingly, when the runout H of the cutting tool T exceeds the runout allowable value Pb, the cutting tool T does not come into contact with the spring pin P3. Conversely, if the runout H of the cutting tool T is within the runout allowable value Pb, the cutting tool T and the spring pin P3 come into contact as shown in FIG. 7C. Therefore, it is possible to determine whether the runout H of the cutting tool T is within the runout allowable value Pb by setting L2-L1 to a value obtained by subtracting the runout allowable value Pb from the radius D / 2 of the cutting tool T. Become.
[0023]
Whether the cutting tool T is in contact with the spring pin P3 can be detected, for example, based on whether the spring pin P3 and the cutting tool T are energized. Specifically, the voltage V is applied to the spring pin P3, and the cutting tool T is grounded. When the cutting tool T contacts the spring pin P3, the spring pin P3 is set via the cutting tool T, and the voltage of the spring pin P3 becomes 0V. Therefore, whether the cutting tool T and the spring pin P3 are in contact with each other can be detected based on the voltage of the spring pin P3.
[0024]
Note that the detection device according to the second embodiment can be used in various modes other than the above-described usage method.
For example, the distance (L2-L1) from the rotation axis to the spring pin when the rotation axis is positioned may be a value obtained by adding the run-out allowable value Pb to the radius D / 2 of the cutting tool T (that is, L2-L1 = D / 2 + Pb). In this case, if the runout of the cutting tool does not exceed the allowable value Pb, the cutting tool does not contact the spring pin P3 as shown in FIG. 8A. On the other hand, when the run-out of the cutting tool exceeds the allowable value Pb, the cutting tool trajectory becomes large as shown in FIG. 8B, and the cutting tool comes into contact with the spring pin P3. Therefore, as in the case described above, by detecting the presence or absence of contact between the spring pin P and the cutting tool T, it is possible to determine whether or not the runout of the cutting tool exceeds an allowable value.
Alternatively, it may be detected whether or not the cutting tool T and the spring pin P3 are in contact with each other while moving the rotation axis of the rotating shaft so as to gradually approach the spring pin P3. In this case, first, the distance Ls between the rotation axis of the rotation shaft and the spring pin P3 when the cutting tool T and the spring pin P3 start to contact is determined. That is, the distance Ls between the rotation axis of the rotating shaft and the spring pin P3 when the cutting tool T comes into contact with the spring pin P3 only when the cutting tool T swings most toward the spring pin P3 is determined.
Next, the distance Lf between the rotation axis of the rotating shaft and the spring pin P3 when the cutting tool T and the spring pin P3 come into contact with each other during one rotation of the cutting tool T is determined. That is, the distance Lf between the rotation axis of the rotating shaft and the spring pin P3 when the cutting tool T comes into contact with the spring pin P3 even when the cutting tool T touches the opposite side of the spring pin P3 most is obtained. When these two distances Ls and Lf are obtained, the runout amount H of the cutting tool T becomes the difference (Ls-Lf) between them.
Also in the second embodiment, as in the first embodiment, by using the cutting tool shown in FIG. 4, it is also possible to detect only runout of the cutting tool in a predetermined direction.
[0025]
Next, a description will be given of a processing apparatus according to a first embodiment provided with the detection apparatus according to the first embodiment. FIG. 9 is a diagram showing a schematic configuration of the processing apparatus according to the first embodiment.
As illustrated in FIG. 9, the processing apparatus includes a processing unit 40 that rotationally drives the cutting tool 42, a detection device 30 that detects a run-out of the cutting tool 42, and a holding unit (not shown) that holds the workpiece. ing.
A spindle motor 22 (not shown in FIG. 9; however, shown in FIG. 11) is accommodated in a casing 41 of the processing unit 40. A spindle 43 is connected to the output shaft of the spindle motor 22. The spindle 43 is rotatably supported by the casing 41, and rotates when the spindle motor 22 rotates. A fitting hole (not shown) is formed at the tip of the spindle 43. The base (formed in a tapered shape) of the cutting tool 42 is fitted into the fitting hole. Therefore, when the spindle 43 rotates, the cutting tool 42 also rotates. At the tip of the cutting tool 42, a blade that is in contact with the workpiece is provided. The cutting tool 42 is made of a metal material, and an insulator as shown in FIG.
The processing unit 40 can be moved in the X-axis direction, the Y-axis direction, and the Z-axis direction by a moving mechanism (a ball screw, a servomotor, or the like) not shown. The movement of the processing unit 40 in the X-axis direction is performed by an X-axis motor 24 (not shown in FIG. 9; however, shown in FIG. 11), and the movement in the Y-axis direction is performed by a Y-axis motor 26 (not shown in FIG. 9; The movement in the Z-axis direction is performed by a Z-axis motor 28 (not shown in FIG. 9; however, shown in FIG. 11).
[0026]
A gantry 44 is erected on the cutting tool 42 side of the processing unit 40 described above, and the detection device 30 is arranged on the gantry 44. FIG. 10 shows the detection device 30 in an enlarged manner.
As shown in FIG. 10, the detection device 30 has a frame 32. A spring pin 36 is erected downward on the upper frame of the frame 32. The fixed end of the spring pin 36 is an energization terminal 37. An insulating collar 38 is provided around the energizing terminal 37 to insulate the spring pin 36 from the frame 32. The power supply terminal 37 is grounded.
On the lower frame of the frame 32, a spring pin 34 is erected upward. Similarly to the above-described spring pin 36, the fixed end of the spring pin 34 is a current-carrying terminal 33, around which an insulating collar 35 is disposed. A predetermined voltage V is applied to the energizing terminal 33.
The spring pins 34 and 36 are formed of an elastically deformable conductive material.
[0027]
As is clear from FIG. 10, the spring pin 34 and the spring pin 36 are arranged in parallel. The distance L between the spring pin 34 and the spring pin 36 is a value obtained by subtracting twice the allowable runout value Pb from the outer diameter D of the cutting tool 42 (that is, L = D−2 × Pb). Further, the spring pins 34 and 36 are arranged at an angle θ with respect to the Y axis of the processing unit 40. Therefore, when the processing unit 40 is moved in the Y-axis direction, its trajectory is inclined with respect to the spring pins 34 and 36.
Further, the detection device 30 is disposed so as to face the spindle 43. That is, the rotation axis of the spindle 43 is orthogonal to the plane including the spring pins 34 and the spring pins 36. Therefore, the cutting tool 42 attached to the spindle 43 is also substantially perpendicular to the plane including the spring pins 34 and 36. Although the axis of the cutting tool 42 and the axis of the spindle 43 are slightly shifted depending on the state of attachment of the cutting tool 42 to the spindle 43, the difference is very small. , 36 are substantially perpendicular to the plane.
[0028]
FIG. 11 shows a control configuration of the above-described processing apparatus. As shown in FIG. 11, a control unit 20 provided in the processing apparatus includes a spindle motor 22 for driving a spindle 43 to rotate, and an X-axis motor 24 for moving the processing unit 40 in the X-axis, Y-axis, and Z-axis directions. , Y-axis motor 26 and Z-axis motor 28 are connected. The control unit 20 controls the spindle motor 22 so that the number of rotations of the spindle 43 becomes a predetermined number of rotations, and moves the X-axis so that the processing unit 40 (that is, the cutting tool 42 attached to the spindle 43) is at a predetermined position. The motor 24, the Y-axis motor 26, and the Z-axis motor 28 are controlled.
In addition, the control unit 20 is connected to an energizing terminal 33 of a spring pin 34 of the detection device 30. Therefore, an electric signal from the power supply terminal 33 is always input to the control unit 20, and the presence or absence of contact between the cutting tool 42 and the spring pins 34 and 36 is determined based on the voltage of the input electric signal.
[0029]
Next, processing performed by the control unit 20 when processing a workpiece in the processing apparatus configured as described above will be described.
FIG. 12 shows a flowchart of the processing performed by the control unit 20. As shown in FIG. 12, the control unit 20 first determines whether or not the cutting tool 42 has been replaced (step S10). That is, it is determined whether the cutting tool 42 has been replaced between the end of the immediately preceding machining process and the start of the current machining process.
If the cutting tool 42 has not been replaced (NO in step S10), the process proceeds to step S16, where a predetermined cutting process is performed on the workpiece. On the other hand, if the cutting tool 42 has been replaced (YES in step S10), the process proceeds to step S12, in which a runout amount detection process is performed to determine whether the runout of the cutting tool 42 is within the runout allowable value Pb.
[0030]
The shake amount detection processing will be described with reference to FIG. As shown in FIG. 13, in the shake amount detection processing, first, the spindle motor 22 is rotated to rotate the spindle 43 at a predetermined rotation speed (S20).
Next, the cutting tool 43 is positioned so that it passes between the spring pins 34 and 36, and the rotation axis of the spindle 43 is at the first position (shown in FIG. 10) (step S22). Specifically, as shown in FIG. 9B, first, the X-axis motor 24 and the Y-axis motor 26 are driven to move the processing unit 40 in the X-axis direction and the Y-axis direction. Next, the processing unit 40 is moved in the Z-axis direction by driving the Z-axis motor 28. The amount of movement of the processing unit 40 in the X-axis, Y-axis, and Z-axis directions is determined and programmed from this positional relationship because the origin position of the processing unit 40 and the installation position of the detection device 30 are known in advance. I have.
In step S24, the processing unit 40 (that is, the rotation axis of the spindle 43) is moved at a predetermined speed in the Y-axis direction by driving the Y-axis motor 26. At this time, the spindle motor 22 remains driven to rotate, and the spindle 43 and the cutting tool 42 are rotated.
When the movement of the machining unit 40 in the Y-axis direction is started in step S24, it is determined whether or not the deflection of the cutting tool 42 in the blade edge direction is an allowable value (that is, the cutting tool 42 and the spring pins 34 and 36 come into contact with each other in a predetermined manner). Is determined (step S26). Whether or not the runout of the cutting tool 42 in the blade edge direction is an allowable value is determined by the method described above. That is, when the voltage of the spring pin 34 changes as shown in FIG. 5 while the cutting tool 42 makes one rotation, it is determined that the run-out of the cutting tool 42 in the cutting edge direction is within an allowable value. During the detection as to whether or not the cutting tool 42 and the spring pins 34 and 36 are in contact with each other, the movement of the processing unit 40 can be stopped, but the movement of the processing unit 40 can be stopped. You may go. That is, when the rotation speed of the spindle 43 is high, the amount by which the processing unit 40 moves during one rotation of the spindle 43 becomes negligibly small. Accordingly, high detection accuracy can be maintained even when the cutting tool 42 and the spring pins 34 and 36 are detected while the processing unit 40 is being moved.
If the run-out of the cutting tool 42 in the direction of the cutting edge is within the allowable value (YES in step S26), it is determined that the run-out of the cutting tool 42 is within the allowable value (step S32), and the run-out detection process ends.
On the other hand, if the run-out of the cutting tool 42 in the blade edge direction exceeds the allowable value [YES in step S26], it is further determined whether or not the rotation axis of the spindle 43 has moved to the second position (shown in FIG. 10). (Step S28). If the rotation axis of the spindle 43 has not moved to the second position [NO in step S28], the process returns to step S24 and repeats the processing from step S24. Therefore, the determination in step S26 is repeatedly performed while moving the rotation axis of the spindle 43 in the Y-axis direction. Conversely, if the rotation axis of the spindle 43 has moved to the second position [YES in step S28], it is determined that the run-out of the cutting tool 42 exceeds the allowable value (step S30), and the run-out detection process ends. .
Therefore, it is determined that the runout of the cutting tool 42 exceeds the allowable value only when the runout of the cutting tool 42 exceeds the allowable value at any position while the rotation axis of the spindle 43 moves from the first position to the second position. Is done. As is clear from FIG. 10, the locus of the rotation axis of the spindle 43 (a straight line connecting the first position and the second position) intersects the center lines of the spring pins 34 and 36. For this reason, by making a determination using the above method, it is determined whether or not the touch of the cutting tool 42 is within an allowable value at a position where the rotation axis of the spindle 43 is on the center line of the spring pins 34 and 36. . Therefore, even when the positioning of the spindle 43 in the X-axis direction (that is, the positioning of the processing unit 40 in the X-axis direction) includes an error due to thermal displacement or mechanical play, the rotation axis of the spindle 43 is not 36 can be passed through the center line. Therefore, the run-out of the cutting tool 42 can be accurately detected.
[0031]
When the run-out detection process is completed, the process returns to step S14 in FIG. 12 to determine whether the run-out of the cutting tool 42 is within an allowable value. If the run-out of the cutting tool 42 is within the allowable value (YES in step S14), the workpiece is cut (step S16).
Conversely, if the run-out of the cutting tool 42 exceeds the allowable value (NO in step S14), the lamp is turned on (S18), and the process ends. Therefore, unless the operator performs processing such as removing foreign matter from the base of the cutting tool 42 and / or the fitting hole of the spindle 43, the workpiece is not cut. Since the cutting is performed only when the deflection of the cutting tool 42 is within the allowable value, the workpiece can be machined with high accuracy.
[0032]
Second Example Next, a processing apparatus according to a second example including the detection device according to the above-described second embodiment will be described. FIG. 14 is a diagram showing a schematic configuration of a processing apparatus according to the second embodiment.
As is clear from FIG. 14, the processing apparatus according to the second embodiment is configured substantially in the same manner as the first embodiment, and only the detection device 50 is different from that of the first embodiment. Hereinafter, only the differences from the first embodiment will be described, and the description of the same portions as the first embodiment will be omitted.
[0033]
FIG. 15 shows a detection device 50 according to the second embodiment. As is clear from FIG. 15, in the second embodiment, only one spring pin 54 stands on the frame 52. The fixed end of the spring pin 54 is an energizing terminal 56, and an insulating collar 58 is arranged around the energizing terminal 56. A predetermined voltage is applied to the power supply terminal 56, and the power supply terminal 56 is connected to the control unit. The cutting tool 42 is grounded.
As shown in FIG. 15, the spring pins 54 are disposed so as to be parallel to the Y-axis direction of the processing unit 40. Therefore, by controlling the position of the processing unit 40 in the X-axis direction, the distance from the rotation axis of the spindle 43 to the spring pin 54 can be controlled.
[0034]
The processing of cutting a workpiece using the processing apparatus according to the second embodiment is performed in substantially the same manner as in the first embodiment, and only the procedure for simply detecting the runout of the cutting tool 42 is different. The procedure for detecting the runout of the cutting tool 42 using the detection device 50 (ie, the procedure for determining whether the runout of the cutting tool 42 is within the allowable value Pb) has already been described with reference to FIG. This is described using (c). Therefore, a detailed description thereof is omitted here, and instead, various measurement processes that can be performed using the detection device 50 will be described.
[0035]
(1) Processing for measuring runout amount of cutting tool 42
A procedure for measuring the runout of the cutting tool 42 will be described. First, a procedure for measuring the runout amount of the entire circumference of the cutting tool 42 will be described with reference to FIG. In addition, in order to measure the runout amount of the entire circumference of the cutting tool 42, a cutting tool 42 having no insulator disposed on the outer circumference is used.
In order to measure the amount of run-out of the cutting tool 42, the X-axis motor 24 is driven to bring the processing unit 40 (the rotation axis of the spindle 43) closer to the spring pin 54 at a predetermined speed. When the spindle 43 is moved toward the spring pin 54, the cutting tool 42 attached to the spindle 43 also approaches the spring pin 54. For this reason, the cutting tool 42 and the spring pin 54 start contacting from the state where the cutting tool 42 and the spring pin 54 do not contact (the state of FIG. 16A) (FIG. 16 ( b)), and finally the cutting tool 42 and the spring pin 54 are always in contact (the state of FIG. 16C).
Here, the state shown in FIG. 16 (b) is a state where the cutting tool 42 and the spring pin 54 are in contact only when the cutting tool 42 oscillates most toward the spring pin 54, and the state shown in FIG. 16 (c). Is a state where the cutting tool 42 and the spring pin 54 are in contact with each other even when the cutting tool 42 swings to the side opposite to the spring pin 54 most. Therefore, the control unit 20 can calculate the run-out amount of the cutting tool 42 by subtracting the position of the spindle 43 in the state shown in FIG. 16C from the position of the spindle 43 in the state shown in FIG.
Note that whether the cutting tool 42 and the spring pin 54 are in the state shown in FIG. 16B or 16C can be determined by the voltage value of the spring pin 54. That is, when the state shown in FIG. 16B is reached, the spring pin 54 is energized instantaneously while the cutting tool 42 makes one rotation. Therefore, the voltage change is as shown on the right side of FIG. Therefore, the control unit 20 monitors the voltage of the spring pin 54 and stores the position of the spindle 43 when such a voltage change occurs. When the state shown in FIG. 16C is reached, the spring pin 54 and the cutting tool 42 are always in contact with each other while the cutting tool 42 makes one rotation. Therefore, the voltage change of the spring pin 54 is as shown on the right side of FIG. Therefore, the control unit 20 stores the position of the spindle 43 when the voltage change of the spring pin 54 always starts to be 0V.
[0036]
When measuring the amount of run-out of the cutting tool 42 in a specific direction, the cutting tool 42 having an insulator disposed on its outer periphery as shown in FIG. 4 is used. Also in this case, the spindle 43 is approached toward the spring pin 54, and the position of the spindle 43 when only one of the non-insulating portions 42a comes into contact (the state shown in FIG. 17A) is obtained. The position of the spindle when the insulating portions 42a and 42b come into contact with each other (the state shown in FIG. 17B) is obtained. When the positions of the two are determined, the difference is calculated, and the amount of runout of the cutting tool 42 in a specific direction is measured.
[0037]
(2) Processing for measuring the runout direction of the cutting tool 42
In order to measure the run-out direction of the cutting tool, for example, a cutting tool 100 as shown in FIG. As shown in FIG. 18A, a contact portion (for example, a tool holder) of the cutting tool 100 with the spring pin 54 has a multilayer structure. That is, the high conductive layers 106a and 106b having a low electric resistance value, the low conductive layer 102 having a high electric resistance value disposed between the two high conductive layers 106a and 106b, and the low conductive layer 102 and the two high conductive layers It is composed of insulating layers 104a and 104b that insulate the layers 106a and 106b. Therefore, when the high conductive layer 106a or 106b makes contact with the spring pin 54, the current value of the current flowing from the spring pin 54 to the cutting tool 100 becomes high, while when the low conductive layer 102 makes contact with the spring pin 54, the spring The current value of the current flowing from the pin 54 to the cutting tool 100 decreases. Thus, it can be determined which part (high conductive layer, low conductive layer) of the cutting tool 100 is in contact with the spring pin 54.
When detecting the run-out direction using the cutting tool 100, first, the X-axis motor 24 is driven to move the processing unit 40 (the rotation axis of the spindle 43) toward the spring pin 54 at a predetermined speed. When the processing unit 40 is moved, the cutting tool 100 also approaches the spring pin 54. Therefore, the contact time between the cutting tool 100 and the spring pin 54 gradually increases with the movement of the processing unit 40, and finally the connection is always established. Here, the time when the cutting tool 100 and the spring pin 54 come into contact with each other at all times is the time when the cutting tool 100 swings most in the direction away from the spring pin 54. For this reason, the contact portion with the spring pin when the two are always in contact with each other is in the runout direction of the cutting tool 100.
Therefore, in order to determine the deflection direction of the cutting tool 100, the value of the current flowing from the spring pin 54 to the cutting tool 100 is monitored. The timing at which the two pins always start contacting (point A in FIG. 18B) and the timing at which the low conductive layer 102 first contacts the spring pin 54 after starting the constant contacting (point A in FIG. 18B). A time difference t1 from the point B) is obtained. Further, a time t required for the cutting tool 100 to make one rotation (time from the point B to the point C in FIG. 18B) is obtained. When these are known, the deflection direction can be determined to be a direction shifted from the low conductive layer 102 by (t1 / t) × 360 °.
[0038]
As described above, some preferred embodiments of the present invention have been described in detail, but these are merely examples, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. it can.
In each of the above-described embodiments, whether or not the spring pin and the cutting tool have contacted is determined based on whether or not the spring pin and the cutting tool are energized. However, the determination of the presence or absence of contact between the spring pin and the cutting tool is not limited to the above-described method based on the presence or absence of energization, and various methods can be employed. For example, the contact between the spring pin and the cutting tool may be determined by detecting the presence or absence of the vibration of the spring pin. That is, when the spring pin is vibrating, it is determined that it is in contact, and when the spring pin is not vibrating, it is determined that it is not in contact. Further, the contact between the spring pin and the cutting tool may be determined by detecting whether or not the spring pin is bent. That is, if the spring pin is bent, it is determined that the spring pin is in contact, and if the spring pin is not bent, it is determined that it is not in contact. Whether or not the spring pin is bent can be detected by attaching a strain gauge or the like to the spring pin. Further, the contact between the spring pin and the cutting tool may be determined by detecting the presence or absence of the contact noise between the spring pin and the cutting tool. When the contact sound is detected, it is determined that the spring pin and the cutting tool are in contact, and when the contact sound is not detected, it is determined that the spring pin and the cutting tool are not in contact. The contact sound can be detected by a microphone or the like. Further, both the detection device 30 of the first embodiment and the detection device 50 of the second embodiment described above may be provided in the processing device. In this case, for example, first, the deflection amount of the cutting tool is detected by the detection device 50 of the second embodiment. If the measured runout exceeds the allowable value, a warning is issued so that the mounting failure of the cutting tool is eliminated. If the runout of the cutting tool is within the allowable value, the detection device 30 of the first embodiment again accurately detects whether the runout of the cutting tool is within the allowable value. With such a configuration, it is possible to prevent a situation in which the two spring pins are damaged by inserting a cutting tool having a large runout between the two spring pins.
Further, as shown in FIG. 19, one spring pin may be erected in a position in which the swing allowable value Pb is further considered by α in front of the two spring pins of the detection device 30 (spindle side). good. By detecting the amount of run-out by using one spring pin that contacts in advance, it is possible to prevent the two spring pins of the detection device 30 from being damaged.
The technical elements described in the present specification or the drawings exhibit technical utility independently or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Further, the technology exemplified in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a principle of detecting runout of a cutting tool by a detection device according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a voltage change of a spring pin in the detection device according to the first embodiment.
FIG. 3 is a diagram for explaining the deflection direction of a cutting tool and the effect on a machined surface.
FIG. 4 is a diagram showing a configuration of a cutting tool for detecting run-out of the cutting tool in a specific direction.
FIG. 5 is a diagram showing a voltage change of a spring pin when the cutting tool shown in FIG. 4 comes into contact with the spring pin.
FIG. 6 is a diagram showing a locus of a rotary shaft to which the cutting tool of the first embodiment is attached and a positional relationship between spring pins P1 and P2.
FIG. 7 is a diagram illustrating an example for detecting runout of a cutting tool by a detection device according to a second embodiment of the present invention.
FIG. 8 is a diagram showing another example for detecting runout of a cutting tool by the detection device according to the second embodiment of the present invention.
FIG. 9 is a view showing a schematic configuration of a processing apparatus according to a first embodiment of the present invention.
FIG. 10 is a diagram showing a mechanical configuration of a detection device provided in the processing device of the first embodiment.
FIG. 11 is a block diagram illustrating a control configuration of the processing apparatus according to the first embodiment.
FIG. 12 is a flowchart when cutting is performed by the processing apparatus of the first embodiment.
FIG. 13 is a flowchart of a shake amount detection process.
FIG. 14 is a view showing a schematic configuration of a processing apparatus according to a second embodiment of the present invention.
FIG. 15 is a diagram showing a mechanical configuration of a detection device provided in the processing device of the second embodiment.
FIG. 16 is a diagram for explaining a procedure for measuring a runout amount (all around) of a cutting tool using the processing apparatus of the second embodiment.
FIG. 17 is a diagram for explaining a procedure for measuring a runout amount (specific direction) of a cutting tool using the processing apparatus of the second embodiment.
FIG. 18 is a view for explaining a procedure for measuring a run-out direction of a cutting tool using the processing apparatus of the second embodiment.
FIG. 19 is a diagram for explaining the configuration of another detection device.
[Explanation of symbols]
T ・ ・ Cutting tool
P1 spring pin
P2 ・ Spring pin
20 Control unit
22 ・ ・ Spindle motor
24 ... X-axis motor
26..Y-axis motor
28 ・ ・ Z axis motor
30 ・ ・ Detection device
40 ・ ・ Processing unit

Claims (9)

An apparatus for detecting run-out of a rotating cutting tool attached to a rotating shaft,
An elastically deformable first contact piece;
An elastically deformable second contact piece disposed parallel to the first contact piece and at a position separated by a value obtained by subtracting a predetermined value from the outer diameter of the cutting tool;
Means for positioning the cutting tool such that the cutting tool passes between the two contact pieces and is substantially perpendicular to a plane including the two contact pieces, and the rotation axis of the rotation axis is on the center line of the two contact pieces; ,
Means for detecting whether or not the outer periphery of the cutting tool is in contact with the two contact pieces when the cutting tool rotates about the axis. The cutting tool and the two contact pieces are formed of a conductor, and one of the two contact pieces is applied with a predetermined voltage while the other is grounded, and the detecting means determines whether the two contact pieces are energized. The run-out detecting device for a cutting tool according to claim 1, wherein the detection is performed. The run-out detecting device for a cutting tool according to claim 2, wherein an outer peripheral surface of the cutting tool is insulated except for a predetermined angle range set in the run-out detection direction. The interval between the two contact pieces is a distance obtained by subtracting twice the allowable run-out value from the outer diameter of the cutting tool, and is detected by the detecting means while the cutting tool positioned by the positioning means makes at least one rotation around the axis. The cutting tool according to any one of claims 1 to 3, further comprising: means for determining whether or not the run-out of the cutting tool exceeds a run-out tolerance based on a contact state between the cutting tool and the two contact pieces. A shake detection device. The said positioning means moves a cutting tool so that the rotation axis of the said rotating shaft may move on the inclined line which cross | intersects with the center line of two contact pieces in the plane containing two contact pieces. Item 5. The runout detection device for a cutting tool according to any one of Items 1 to 4. An apparatus for detecting run-out of a rotating cutting tool attached to a rotating shaft,
An elastically deformable contact piece;
Means for positioning the cutting tool such that the distance from the rotation axis of the rotation shaft to the contact piece is a predetermined value,
Means for detecting whether or not the outer periphery of the cutting tool is in contact with the contact piece when the cutting tool rotates about the axis. The cutting tool and the contact piece are formed of a conductor, and a predetermined voltage is applied to one of the cutting tool and the contact piece, while the other is grounded, and the detecting means is turned on by the cutting tool and the contact piece. The run-out detecting device for a cutting tool according to claim 6, wherein whether or not the run-out is detected is determined. The positioning means is for positioning the cutting tool so that the distance from the axis of rotation of the rotating shaft to the contact piece is a distance obtained by subtracting a run-out allowance from the radius of the cutting tool, and is positioned by the positioning means. Means for determining whether or not the run-out of the cutting tool is within an allowable value based on the contact state between the cutting tool and the contact piece detected by the detecting means during at least one rotation of the cutting tool around the axis. The deflection detecting device for a cutting tool according to claim 6 or 7, further comprising: An elastically deformable first contact piece, and an elastically deformable second contact piece disposed in a position parallel to the first contact piece and separated by a value obtained by subtracting a predetermined value from the outer diameter of the cutting tool. A method of detecting run-out of a rotating cutting tool attached to a rotating shaft using a contact piece,
The cutting tool passes between the two contact pieces and is substantially orthogonal to the plane including the two contact pieces, and on a slope line intersecting the center line of the two contact pieces in the plane including the two contact pieces. Positioning the cutting tool so that the rotation axis of the rotation shaft is located at a predetermined position,
Rotating the positioned cutting tool at least one rotation around the axis, and detecting whether the outer circumference of the cutting tool is in contact with the two contact pieces during one rotation of the cutting tool,
A run-out detection method for a cutting tool, wherein the positioning step is repeatedly performed to move a rotation axis of the rotary shaft on the inclined line, and the detection step is performed for each position determined by the positioning step.

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