JP2011148042A - Method for setting original point of workpiece of machine tool, and machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for setting an original point of workpiece of a machine tool, that can set an original point of workpiece with accuracy and with efficiency; and to provide the machine tool. <P>SOLUTION: A method for setting original point of workpiece of a machine tool is to attach a machine vise 20 on a stage 30 and to level the machine vise 20; to move and adjust a position of a main shaft 11 to a reference hole 21, and to perform a centering of the main shaft 11 to the reference hole 21, which matching the axial center of the main shaft 11 to the axial center of the reference hole 21. Then, the position of the axial center of the main shaft 11 when completing the leveling is set as the original point of workpiece. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a workpiece origin setting method for a machine tool and a machine tool.

When using a machine tool (for example, a general-purpose milling machine), the work origin may be started after first setting the workpiece origin. As a technique related to the setting of the workpiece origin, for example, Patent Document 1 describes a workpiece origin position detection device (hereinafter referred to as “origin position detection device”).
The origin position detection device is provided on a contact pin whose outer peripheral surface is finished with high accuracy, a holding body that holds the contact pin so as to be movable in a radial direction, and an outer periphery of the contact pin. Display means for displaying when the surface contacts the workpiece.
The origin position detecting device is configured such that when the workpiece is moved and the workpiece end face comes into contact with the contact pin, the display means (light emitting diode) is energized and lit. Then, by confirming that the light-emitting diode is turned on, the position of the workpiece end surface with respect to the spindle is detected, and the workpiece origin is set.

However, when the workpiece tries to move further after coming into contact with the contact pin, the contact pin is supported so as not to rotate, and therefore bends by receiving a pressing force from the workpiece. This causes a problem that the workpiece is overrun, the detection accuracy is deteriorated, and the workpiece origin cannot be accurately set.
The overrun of the work can be prevented by stopping the work by the worker simultaneously with the start of lighting of the light emitting diode. However, since the worker stops the work after confirming that the light emitting diode is turned on, a time lag is likely to occur, and it is practically difficult to prevent the work from being overrun.

  Further, when the detection work is repeatedly performed using the same contact pin, the contact pin is deformed into a bent state by a pressing force from the workpiece during the work, and the detection work is continued with the bent contact pin. Sometimes. At this time, the detection accuracy deteriorates, causing a problem that the work origin cannot be set with high accuracy.

The origin position detecting device needs to contact the contact pin with the workpiece end surface when setting the workpiece origin.
Thereby, in the above-described origin position detection device, for example, as shown in FIG. 15, when the workpiece end surface 100a of the workpiece 100 is not perpendicular to the surface and the axial direction of the contact pin 110 is not parallel to the workpiece end surface 100a, The position of the workpiece end surface 100a cannot be accurately detected, and as a result, the workpiece origin cannot be accurately set. That is, the setting accuracy of the workpiece origin is affected by the workpiece shape.

  Patent Document 1 describes a method of detecting the position of the workpiece end surface with respect to the spindle of the machine tool by the following procedures (1) to (4) and setting the detected position as the workpiece origin. .

(1) A dial gauge is attached to the main shaft, and the reference hole formed in the ring gauge is centered by the dial gauge. When the centering of the dial gauge is completed, the dial gauge pointer is rotated by an amount corresponding to the dimension (A) of the inner diameter of the reference hole (ie, the dimension (A / 2)). To suit.
(2) A dial gauge probe is brought into contact with the workpiece end face.
(3) The spindle is moved to a position where the dial gauge pointer becomes 0 with the probe contacting the workpiece end surface.
(4) When the dial gauge pointer is 0, it is detected that the workpiece end face is at a position (A / 2) away from the spindle. A position separated by (A / 2) from the spindle is set as the workpiece origin.

  However, since the reference hole is formed in a ring gauge that is separate from the support member that supports the workpiece, the ring cage is inclined with respect to the main shaft even though the support member accurately supports the workpiece. The situation where it is arranged in the state where it has done can occur. At this time, the axial direction of the reference hole is inclined with respect to the axial direction of the main shaft, and the centering operation in the above (1) cannot be performed with high accuracy. As a result, the accuracy of the position of the workpiece end surface with respect to the main shaft detected in (4) above is deteriorated, and as a result, there is a problem that the workpiece origin cannot be set accurately.

  The above problem can be solved by adding an operation for adjusting the attitude of the ring cage. However, there is a problem that the work man-hours increase and the work efficiency deteriorates.

Further, as a device for positioning a workpiece, there is a device as shown in Patent Document 2.
The apparatus described in Patent Document 2 is obtained by fixing a positioning member to a base of a machine vise with a positioning pin.
However, the positioning accuracy is determined by the spacing and arrangement of the positioning pins, and high-accuracy positioning cannot be performed according to the size and shape of the workpiece.

Japanese Patent Laid-Open No. 9-287938 Japanese Utility Model Publication No. 4-32857

  The present invention provides a workpiece origin setting method for a machine tool that can set the workpiece origin accurately and can be set efficiently, and a machine tool.

  The workpiece origin setting method for a machine tool according to claim 1, wherein a spindle to which a tool for machining the workpiece can be attached, a reference hole is formed at a predetermined position on the outer peripheral surface, and the workpiece is positioned at a fixed position with respect to the reference hole. And a support member that supports the workpiece in a state in which the workpiece is positioned by the positioning portion, and a stage that is configured to be detachable and support the support member. A workpiece origin setting method for a machine, wherein the support member is attached to the stage, the support member is leveled, the position of the spindle relative to the reference hole is moved and adjusted, and the spindle axis and the spindle Aligning the axis of the reference hole with the reference hole, aligning the spindle with respect to the reference hole, and setting the position of the axis of the spindle when the alignment is completed as the workpiece origin. .

  3. The work origin setting method for a machine tool according to claim 2, wherein the main shaft is configured to be attachable with a centering member having a measuring element that is rotatably supported, and the main shaft is centered with respect to the reference hole. When the centering member attached to the main shaft is rotated around the main shaft together with the main shaft in a state where the rotation center of the measuring device is aligned with the axis of the main shaft, Is performed by moving and adjusting the position of the main shaft with respect to the reference hole so as to maintain a certain amount of rotation in contact with the inner peripheral surface of the reference hole.

  The workpiece origin setting method for a machine tool according to claim 3, wherein a spindle that can be attached to a tool for machining a workpiece and a centering member having a measuring element that is rotatably supported, and a predetermined position on an outer peripheral surface A reference hole having a diameter of a predetermined dimension is formed on the workpiece, and a workpiece origin setting of a machine tool having a support member that supports the workpiece, and a stage that is configured to be detachable from the support member and supports the support member. The method includes: attaching the support member to the stage, leveling the support member, and attaching the core to the main shaft in a state where the rotation center of the probe coincides with the axis of the main shaft When the take-out member is rotated around the axis of the main shaft together with the main shaft, the measuring element of the main shaft is maintained so as to maintain a certain amount of rotation in a state where the probe contacts the inner peripheral surface of the reference hole. For reference hole The position of the spindle is aligned with the axis of the reference hole, the center of the spindle is aligned with respect to the reference hole, and the measuring element is attached to the work supported by the support member. The main shaft is rotated until the rotation amount of the measuring element in contact with the workpiece becomes equal to the rotation amount of the measuring element in contact with the inner peripheral surface of the reference hole when the centering is completed. A position separated from the axis of the main shaft on the side where the contact point between the measuring element and the workpiece exists in a direction orthogonal to the axial direction of the main shaft. Set as the origin.

  The machine tool according to claim 4, wherein a spindle capable of attaching a tool for machining a workpiece, a reference hole is formed at a predetermined position on the outer peripheral surface, and the positioning portion positions the workpiece at a fixed position with respect to the reference hole. And a support member configured to support the workpiece in a state where the workpiece is positioned by the positioning unit, and a stage configured to be detachable from the support member and supporting the support member. Attaching a member, leveling the support member, moving and adjusting a position of the main shaft with respect to the reference hole, and aligning the axis of the main shaft with the axis of the reference hole, the reference of the main shaft Centering the hole is performed, and the position of the axis of the spindle when the centering is completed is set as the workpiece origin.

  6. The machine tool according to claim 5, wherein the main shaft is configured to be attachable with a centering member having a measuring element that is rotatably supported, and the centering of the main axis with respect to the reference hole is performed by the measuring element. When the centering member attached to the main shaft is rotated around the axis of the main shaft together with the main shaft in a state where the rotation center of the main shaft is aligned with the axis of the main shaft, This is performed by moving and adjusting the position of the main shaft with respect to the reference hole so as to maintain a certain amount of rotation while being in contact with the inner peripheral surface.

  According to a sixth aspect of the present invention, there is provided a machine tool having a main shaft to which a tool for processing a workpiece and a centering member having a measuring element supported to be rotatable can be attached, and a predetermined dimension at a predetermined position on an outer peripheral surface. A reference hole having a diameter is formed, and includes a support member that supports the workpiece, and a support member that is configured to be detachable and supports the support member, and the support member is attached to the stage, The support member is leveled, and the centering member attached to the main shaft is rotated around the main shaft together with the main shaft in a state where the rotation center of the probe is aligned with the axis of the main shaft. The position of the main shaft relative to the reference hole is adjusted so that a fixed amount of rotation is maintained in a state where the probe contacts the inner peripheral surface of the reference hole, and the axis of the main shaft is adjusted. And the axis of the reference hole Centering the reference shaft with respect to the reference hole, bringing the probe into contact with the workpiece supported by the support member, and the amount of rotation of the probe in contact with the workpiece is the completion of the alignment. The main shaft is moved until it becomes equal to the amount of rotation of the probe in contact with the inner peripheral surface of the reference hole at the time, and the measurement in the direction perpendicular to the axial direction of the main shaft from the axis of the main shaft The position where the radius of the reference hole is separated is set as the workpiece origin on the side where the contact portion between the child and the workpiece exists.

  The machine tool according to claim 7 is configured to be detachably attached to the reference hole of the support member, and has a cover portion that closes the reference hole.

  According to the present invention, the workpiece origin can be set with high accuracy and can be set efficiently.

It is a schematic block diagram of the milling machine which is 1st embodiment of the machine tool which concerns on this invention. It is the alpha-alpha cross-sectional enlarged view of FIG. It is a flowchart which shows the setting process of a workpiece | work origin. It is a figure which shows the setting process of a workpiece | work origin, (a) is the figure which centers the reference hole with a dial gauge, (b) is the figure which has contacted the contact of the measuring element on the workpiece end surface. is there. FIG. 5 is a partially enlarged perspective view of FIG. FIG. 5 is a partially enlarged view of FIG. It is a schematic block diagram of the milling machine which is 2nd embodiment of the machine tool which concerns on this invention. It is the beta-beta cross-sectional enlarged view of FIG. It is a flowchart which shows the setting process of a workpiece | work origin. It is a figure which shows the setting process of a workpiece | work origin. It is a figure which shows the workpiece | work whose work end surface is not a surface right angle. It is a figure which shows another embodiment of a positioning part. It is a figure which shows another embodiment of a reference | standard hole. It is a figure which shows a cover part. It is a figure which shows the conventional origin position detection apparatus of the workpiece | work.

[First embodiment]
An NC milling machine (hereinafter simply “milling machine”) 1 which is a first embodiment of a machine tool according to the present invention will be described below with reference to the drawings.
In the figure, the arrow X indicates the (+) direction of the X axis, the arrow Y indicates the (+) direction of the Y axis, and the arrow Z indicates the (+) direction of the Z axis. In the following description, the XY axis direction indicates the plane direction and the Z axis indicates the vertical direction.

  As shown in FIGS. 1 and 2, the milling machine 1 includes a main shaft 11, a driving device 12, an NC control device 13, a machine vice 20, and a stage 30.

The milling machine 1 attaches an appropriate tool for machining the workpiece 10 to the spindle 11, and moves and rotates the spindle 11 to move and rotate the tool 10 to machine the workpiece 10.
Further, the milling machine 1 performs NC machining on the workpiece 10 by numerical control instructing the path of the spindle 11 and other work processes necessary for machining the workpiece 10 by numerical information corresponding thereto, NC (Numerical Control). It is a machine tool.

The workpiece 10 is an object to be processed by the milling machine 1 and has a bottom surface, a top surface, and a side surface formed as a flat surface, and a substantially rectangular parallelepiped outer shape.
Further, the milling machine 1 performs cutting such as drilling and grooving on the upper surface of the workpiece 10.

The main shaft 11 is disposed with its axis oriented in the Z-axis direction, and is moved by the drive device 12 in the plane direction (XY-axis direction) and in the approaching / separating direction (Z-axis direction). At the same time, it is driven to rotate with the direction of approaching / separating from the workpiece 10 as the rotation axis direction.
The drive device 12 is connected to the NC control device 13, and the drive device 12 controls the movement / rotation drive of the spindle 11 based on a control signal from the NC control device 13.
At the time of processing, the workpiece 10 is supported and fixed by the machine vise 20. The machine vice 20 is fixed on the stage 30.

The milling machine 1 is configured to be able to set the workpiece origin separately from the machine origin.
The machine origin is an origin inherent to the milling machine 1 and is an absolute reference position of the spindle 11. On the other hand, the workpiece origin is a relative reference position of the spindle 11 that is arbitrarily set according to the shape of the workpiece 10 to be processed.
The workpiece origin can be set at any convenient location for the operator. As a result, when the machining position of the workpiece 10 is indicated by the coordinate value of the workpiece coordinate system with the workpiece origin as the origin, the value can be made clear, the dimensions of the design drawing can be used as they are, and the machining position can be set. It becomes easy.
For example, in the workpiece 10 of the present embodiment, the position of the end point formed at a right angle is set as the workpiece origin, the workpiece coordinate system based on the distance from the end point is set, and machining by the milling machine 1 can be performed ( (See FIG. 2).

The spindle 11 is supported by attaching a tool (such as a drill) for machining the workpiece 10.
The main shaft 11 is supported on a support base (not shown) so as to be rotatable about an axis and movable in the XYZ axis directions.
The main shaft 11 has a chuck (not shown) at the tip, and is configured so that a tool can be gripped by the chuck. Further, the main shaft 11 is configured to be able to grip the dial gauge 40 in place of the tool by the chuck (see FIG. 5).
When machining the workpiece 10, a tool is attached to the spindle 11 via the chuck, and when setting the workpiece origin, a dial gauge 40 is attached to the spindle 11 via the chuck.

The drive device 12 is a drive source that moves and rotates the main shaft 11.
As shown in FIGS. 1 and 2, the driving device 12 is connected to a main shaft 11, and an X-axis servo motor that moves the main shaft 11 in the X-axis direction, a Y-axis servo motor that moves in the Y-axis direction, and Z It has a Z-axis servo motor that moves in the axial direction and a spindle motor that rotates around the axis.
The drive device 12 is connected to the NC control device 13 and moves and rotates the spindle 11 based on a control signal from the NC control device 13.

  The NC control device 13 is a control device that controls the driving of the spindle 11 by the drive device 12 by numerical control, and includes an input unit 14, a control unit 15, and a display unit 16.

The input unit 14 is connected to the control unit 15 and is configured to be able to input information relating to the position of the workpiece origin and information relating to the machining position of the workpiece 10 (coordinate values in the workpiece coordinate system).
The control unit 15 is configured to be able to set the workpiece origin, and the workpiece origin is set in the control unit 15 by inputting information related to the position of the workpiece origin to the input unit 14.
When the information related to the machining position of the workpiece 10 is input to the input unit 14 after setting the workpiece origin, the control unit 15 creates a machining program based on this information.
The control unit 15 is connected to the drive device 12 and controls the movement / rotation of the main shaft 11 by developing the machining program, and moves the main shaft 11 to the position input to the input unit 14. Thereby, the target position of the workpiece 10 is processed.
The display unit 16 is connected to the control unit 15 and configured to display information related to the position of the spindle 11.

The machine vise 20 is a member that fixes and supports the workpiece 10 in a predetermined posture.
The machine vise 20 has a reference hole 21 that is machined with high accuracy (the inside diameter is machined to a predetermined dimension (A) and the inner circumference is machined into a perfect circle), and the workpiece origin is set. Is performed using the reference hole 21.
The machine vise 20 includes a support part 22, a fixed part 23, a fixed base 24, a movable base 25, and a base fastening screw 26.

The support part 22 is a member that forms the main structure of the machine vise 20, and the work 10 is sandwiched between the fixed base 24 and the movable base 25 on the support part 22, and is fixed and supported in a state of maintaining a predetermined posture. The
The support portion 22 is fixed on the stage 30. A fixing part 23 is fixed on the support part 22.

A fixed base 24 is fixed to the fixed portion 23, and the fixed base 24 is supported by the fixed portion 23.
The fixed base 24 is formed in a rectangular parallelepiped shape, and a reference hole 21 is formed on an end surface (upper surface in the drawing) on the (+) direction side of the Z axis. The reference hole 21 is formed with high accuracy as described above, and is formed so that the diameter dimension is (A) (see FIG. 2).
The portion of the fixed base 24 that comes into contact with the workpiece 10 has a shape corresponding to the shape of one side end of the workpiece 10, and in the present embodiment, according to the shape of the workpiece 10 having a substantially rectangular parallelepiped shape, It is formed in a plane.

A movable base 25 is movably mounted on the support portion 22, and the movable base 25 is disposed opposite to the fixed base 24. In addition, the movable base 25 is slidable in the direction of approaching / separating from the fixed base 24.
On the opposite side of the movable base 25 to the side facing the fixed base 24, a base fastening screw 26 is arranged. The base fastening screw 26 is supported so as to be rotatable about an axis. When the base fastening screw 26 is rotated in one direction, the base fastening screw 26 moves in a direction close to the fixed base 24, and accordingly, the movable base 25 is moved to the fixed base 24. It is pushed and moved in the approaching direction. Conversely, when the base clamping screw 26 is rotated in the other direction, the base clamping screw 26 moves away from the fixed base 24, thereby releasing the pressing force on the movable base 25 by the base clamping screw 26. Can slide in a direction away from the fixed base 24 (see FIG. 1).

  In the machine vise 20 configured as described above, the cap fastening screw 26 is rotated in one direction on the support portion 22 with the workpiece 10 being disposed between the fixed cap 24 and the movable cap 25. Then, the workpiece 10 is sandwiched and fixed between the fixed base 24 and the movable base 25. Further, when the cap tightening screw 26 is rotated in the other direction from the state in which the workpiece 10 is fixed, the workpiece 10 is released from the state in which it is sandwiched and fixed between the fixed base 24 and the movable base 25, and the workpiece 10 10 can be removed from the machine vise 20.

  The fixed base 24 may be configured integrally with the fixed portion 23, or may be configured to be detachable from the fixed portion 23 and may be configured separately from the fixed portion 23.

The stage 30 is a member that supports the machine vise 20.
The stage 30 is a plate-shaped member, and is disposed so as to face the main shaft 11 on the (−) direction side of the Z axis. The stage 30 has a board surface 30 a that faces the main shaft 11, and is arranged so that the board surface 30 a is in a posture orthogonal to the axial direction of the main shaft 11. That is, the board surface 30a is arrange | positioned so that it may become a horizontal surface. Further, the support portion 22 of the machine vice 20 can be attached (fixed) to the board surface 30a.
The workpiece 10 is processed with the machine vise 20 attached on the stage 30 (the board surface 30a) and further supported by the machine vise 20 (fixed by being sandwiched between the fixed base 24 and the movable base 25). Made.
The machine vise 20 is configured to be detachable from the stage 30 (board surface 30a), and other types of workpiece 10 fixing jigs can be attached to the board surface 30a in place of the machine vise 20, which is versatile. It has a configuration.
In the present embodiment, the machine vise 20 is fixed on the stage 30 and the main shaft 11 side is moved in the three directions of the XYZ axes. However, the stage 30 is moved in the XY axis direction and the main shaft 11 side is moved to the Z direction. It is good also as a structure which moves to an axial direction.

The dial gauge 40 is a centering member used when setting the workpiece origin, and is constituted by a known dial gauge.
As shown in FIG. 5, the dial gauge 40 includes a main body portion 41, a measuring element 42, and a display portion 43.
The main body 41 is configured such that one side thereof can be gripped coaxially with the main shaft 11 by a chuck of the main shaft 11, and on the other side, the base end portion of the measuring element 42 can tilt with respect to the Z-axis direction. It is attached.
The measuring element 42 is a rod-shaped member and is supported by the main body 41 so as to be arranged coaxially with the core of the main shaft 11. The measuring element 42 is supported by the main body 41 so as to be rotatable around the base end part, and has a substantially spherical contact 42a at the tip. That is, the contact 42a is configured to rotate in one direction around the base end portion (core of the main shaft 11) of the main body portion 41 in plan view.
The display unit 43 is provided on the main body unit 41 and includes a pointer 43a and a scale plate 43b.
The pointer 43a is supported so as to be rotatable on the scale plate 43b. The pointer 43a is connected to the proximal end portion of the measuring element 42 and rotates on the scale plate 43b in conjunction with the rotation of the measuring element 42.
Scales are displayed on the scale plate 43b side by side on the turning locus of the pointer 43a. When the measuring element 42 rotates, the indicator 43a rotates together, and the scale according to the amount of rotation of the measuring element 42 is obtained. It is configured to indicate a value. In other words, the amount of rotation of the measuring element 42 (the amount of movement of the contact element 42a) can be detected by checking the scale value indicated by the pointer 43a.

The work origin of the milling machine 1 is set in the following order (1) to (5) (see FIG. 3).
The spindle 11 was centered using the reference hole 21 in a state where the machine vise 20 was attached to the stage 30 and the workpiece 10 was supported by the machine vise 20 in a predetermined posture. From the positional relationship between the spindle 11 and the workpiece 10, the workpiece origin is set. In this case, the position on the most negative side in the X-axis direction and the Y-axis direction of the work 10 supported and fixed to the machine vise 20 is set as the work origin (0, 0).
In addition, since the workpiece origin in the X-axis direction and the workpiece origin in the Y-axis direction can be set with the same configuration, in the following description, the position of the workpiece end surface 10a in contact with the fixed base 24 (FIGS. 1 and 2). Reference is made to a configuration for setting the workpiece origin (X = 0) in the X-axis direction.

(1) As shown in FIGS. 1 and 2, the machine vice 20 is attached to the stage 30 (attachment step: S11).
When the machine vice 20 is attached to the stage 30, the posture of the machine vise 20 is usually adjusted.
The posture of the machine vise 20 is adjusted by, for example, leveling the machine vise 20 installed on the board surface 30 a of the stage 30, and the machine vise 20 is in a horizontal direction that is perpendicular to the axial direction of the main spindle 11, that is, a horizontal board surface. It is to adjust the posture of the machine vise 20 so that it is installed in parallel with 30a.
By adjusting the posture of the machine vise 20, the machine vice 20 is prevented from supporting the workpiece 10 in an inclined state with respect to the main shaft 11, and the machine vice 20 accurately supports the workpiece 10.
As described above, since the reference hole 21 is formed in the fixed base 24 of the machine vise 20, when the attitude adjustment operation of the machine vise 20 is performed, the attitude of the reference hole 21 is also adjusted at the same time. Specifically, the axial direction of the reference hole 21 is adjusted so as to coincide with the axial direction of the main shaft 11.

(2) As shown in FIGS. 4A and 5, the dial gauge 40 is attached to the chuck of the main shaft 11, and the reference hole 21 of the fixed base 24 is centered by the dial gauge 40 (centering process: S12).
The centering of the reference hole 21 is such that the main shaft 11 exists at a position where the axis of the main shaft 11 and the axis of the reference hole 21 coincide with each other, and the contact 42a (tip) of the measuring element 42 is moved from the main shaft 11 to the main shaft 11. The position of the main shaft 11 with respect to the reference hole 21 and the amount of rotation of the measuring element 42 are adjusted so that the reference hole 21 exists in a position (radial position (A / 2) away) in the direction perpendicular to the axis of the reference hole 21. That is.
The centering of the reference hole 21 is performed by rotating the dial gauge 40 around the axis of the main shaft 11 together with the main shaft 11 in a state where the measuring element 42 (contact 42a) is rotated so as to contact the inner peripheral surface of the reference hole 21. Is done.
That is, when the dial gauge 40 attached to the main shaft 11 is rotated around the axis of the main shaft 11 together with the main shaft 11 in a state in which the rotation center of the measuring surface 42 coincides with the axis of the main shaft 11, the measuring surface 42 is used. The position of the spindle 11 with respect to the reference hole 21 is moved and adjusted so that a certain amount of rotation is maintained in a state where the shaft is in contact with the inner peripheral surface of the reference hole 21, and the axis of the spindle 11 and the axis of the reference hole 21 are adjusted. Is aligned with the reference hole 21 of the spindle 11.
When the dial gauge 40 is rotated once around the axis of the main shaft 11, the contact 42 a is in contact with the inner peripheral surface of the reference hole 21, and the pointer 43 a of the dial gauge 40 does not move and is constant. When the centering is confirmed, the pointer 43a of the dial gauge 40 is set to “0”. As a result, when the pointer 43a of the dial gauge 40 indicates “0”, the contact 42a of the measuring element 42 exists at a position away from the main shaft 11 in the direction orthogonal to the axis of the main shaft 11 (A / 2). It is estimated that

  (3) As shown in FIGS. 4B and 6, the main shaft 11 is moved in the (+) direction of the Z axis, and the contact 42 a of the measuring element 42 is moved out of the reference hole 21. Thereafter, the main shaft 11 is moved in the (+) direction of the X axis, and the contact 42a is brought into contact with the workpiece end surface 10a of the workpiece 10 supported by the machine vice 20 (contact process: S13).

(4) Further, the contact 42a is tilted in the (−) direction of the X axis with respect to the axial direction of the main shaft 11 in a state of being in contact with the workpiece end surface 10a, and the pointer 43a of the dial gauge 40 becomes “0”. The main shaft 11 is moved in the (+) direction of the X axis (moving step: S14).
That is, until the rotation amount of the measuring element 42 in contact with the workpiece end surface 10a of the workpiece 10 becomes equal to the rotation amount of the measuring element 42 in contact with the inner peripheral surface of the reference hole 21 when the centering is completed. The main shaft 11 is moved.

(5) With the contact 42a tilted in the (−) direction of the X axis with respect to the axial direction of the main shaft 11, the workpiece end surface 10a is the axis of the main shaft 11 when the pointer 43a of the dial gauge 40 points to “0”. It is detected that the position is (A / 2) away from the core in the (−) direction of the X axis (see FIG. 6).
A position (A / 2) away from the main shaft 11 in the (−) direction of the X axis is set (stored) in the control unit 15 as the work origin (X = 0) (setting step: S15).

With the configuration as described above, if the machine vice 20 is leveled in (1) above, the attitude of the reference hole 21 is adjusted at the same time. Therefore, an operation for adjusting the attitude of the reference hole 21 is added. There is no need to do this, work efficiency can be improved, and the work origin can be set efficiently.
In addition, since the attitude of the reference hole 21 is adjusted in (1) above, centering can be performed with high accuracy in (2) above. Thereby, in (5), the position of the workpiece end surface 10a with respect to the spindle 11 can be detected with high accuracy, and the workpiece origin can be set with high accuracy.

Further, in the above (2), the centering is performed by rotating the dial gauge 40 around the axis of the main shaft 11 while bringing the contact 42a of the dial gauge 40 into contact with the inner peripheral surface of the reference hole 21. It is confirmed that the dial gauge 40 is rotated in a state where the contact 42a is in contact with the inner peripheral surface of the reference hole 21 without swinging the pointer 43a, and the main shaft 11 is evenly spaced from the inner peripheral surface of the reference hole 21. Is done by ensuring that
As a result, the center of the reference hole 21 and the center of the main shaft 11 can be centered from point to point, and the centering accuracy is improved.

For example, as shown in FIG. 6, when machining a position (b position) in the workpiece 10 that is (B) away from the workpiece end surface 10 a in the (+) direction of the X axis, In the procedure 5), the position of the workpiece end surface 10a is set to the workpiece origin in the X-axis direction to the control unit 15, and the coordinate value (B) of the X-axis in the workpiece coordinate system is input to the input unit 14. As a result, when machining the workpiece 10, the control unit 15 can move the spindle 11 to the b position and machine the b position with a tool attached to the chuck of the spindle 11.
At this time, since the workpiece origin can be set with high accuracy as described in (5) above, the workpiece 10 can be easily machined with high accuracy.

  In the present embodiment, the reference hole 21 is formed in the fixed base 24 that is a member that directly sandwiches and supports the workpiece 10, and is configured to have a positional relationship close to the workpiece 10 when the workpiece 10 is fixed. Yes. Thereby, after completion of the centering in (2), the work of bringing the contact 42a of the measuring element 42 in (3) into contact with the work end surface 10a of the work 10 can be smoothly performed, and work efficiency can be improved.

  Further, since the milling machine 1 sets the workpiece origin using the dial gauge 40 that detects the workpiece origin by direct contact with the workpiece 10, even if the workpiece 10 is made of a non-energized material such as resin, The origin can be set.

  Further, in the milling machine 1, the measuring element 42 is supported so as to be able to rotate, and is not subjected to a strong pressing force like a contact pin when the workpiece is overrun in the origin position detection device described in Patent Document 1. Therefore, the necessity of ensuring the strength of the measuring element 42 is low. Thereby, the measuring element 42 can be made thin and the contact 42a can be made small. Since the contact 42a can be reduced in this way, when the contact 42a is brought into contact with the workpiece end surface 10a in the above (3), even if the workpiece end surface 10a has some steps and is not flat, the workpiece end surface. The measurement error caused by the step can be reduced. Therefore, the position of the workpiece 10 relative to the spindle 11 can be detected with high accuracy, and the workpiece origin can be set with high accuracy.

[Second Embodiment]
Below, NC milling machine (milling machine) 2 which is 2nd embodiment of the machine tool concerning the present invention is explained with reference to drawings.
Since the milling machine 2 has the same configuration as the milling machine 1, different parts from the milling machine 1 of the first embodiment will be described, the same reference numerals will be given to the same members, detailed description and accompanying descriptions will be given. Description of effects, etc. is omitted.

  The reference hole 21 is formed at a predetermined position on the outer peripheral surface (the upper surface in this example) of the fixed base 24. Specifically, the reference hole 21 is formed at a position where the distance from the center of the reference hole 21 to the end face on the (+) direction side of the X axis in the fixed base 24 is (C).

As shown in FIGS. 7, 8, and 10, the machine vice 20 of the milling machine 2 further includes a positioning unit 50.
The positioning unit 50 is a member that positions the work 10 at a fixed position with respect to the reference hole 21 when the work 10 is sandwiched and supported by the fixed base 24 and the movable base 25.
As shown in FIG. 10, the positioning portion 50 is formed in an L shape corresponding to the shape of the end portion of the fixed base 24, and is disposed to face the end surface of the fixed base 24 on the (−) direction side of the Y axis. Main body 51 and a protrusion 52 that protrudes from the main body 51 in the (+) direction of the Y-axis and is disposed opposite to the opposing surface of the fixed base 24 that faces the movable base 25.

  A long hole 53 extending in the X-axis direction is formed in the main body 51, and a pin 54 is inserted through the long hole 53. The pin 54 is screwed into the end face of the fixed base 24 through the long hole 53. The main body 51 is supported by a pin 54 so as to be slidable in the X-axis direction, and is configured so that the position in the X-axis direction can be changed according to the shape of the workpiece 10 to be positioned.

  The protrusion 52 protrudes to the same position as the axis (center) of the reference hole 21 in the Y-axis direction, and the coordinate value of the Y axis is the same at the tip of the protrusion 52 and the center of the reference hole 21. (See FIG. 8).

When the workpiece 10 is sandwiched and supported by the fixed cap 24 and the movable cap 25, the workpiece end surface 10 b on the (−) direction side of the Y axis of the workpiece 10 is brought into contact with the tip of the protruding portion 52.
By supporting the workpiece 10 in this way, the coordinate values of the Y axis of the workpiece end surface 10b and the center of the reference hole 21 become the same value, and the workpiece 10 is positioned at a fixed position with respect to the reference hole 21. .

The work origin of the milling machine 2 is set in the following order (i) to (iii) (see FIG. 9).
In this example, the position of the center of the reference hole 21 in the machine vise 20 attached to the stage 30 is set as the workpiece origin.

(I) As shown in FIGS. 7 and 8, the machine vice 20 is attached to the stage 30 (attachment step: S21).
When the machine vice 20 is attached to the stage 30, the posture of the machine vise 20 is usually adjusted.
The posture of the machine vise 20 is adjusted by leveling the machine vise 20 installed on the board surface 30a of the stage 30. The machine vise 20 is in a horizontal direction that is a direction orthogonal to the axial direction of the main spindle 11, that is, a horizontal board surface 30a. Is to adjust the posture of the machine vise 20 so that it is installed in parallel.
By adjusting the posture of the machine vise 20, the machine vice 20 is prevented from supporting the workpiece 10 in an inclined state with respect to the main shaft 11, and the machine vice 20 accurately supports the workpiece 10.
As described above, since the reference hole 21 is formed in the fixed base 24 of the machine vise 20, when the attitude of the machine vise 20 is adjusted, the attitude of the reference hole 21 is also adjusted at the same time.

(Ii) As shown in FIG. 10, the dial gauge 40 is attached to the chuck of the main shaft 11, and the reference hole 21 of the fixed base 24 is centered by the dial gauge 40 (centering step: S22).
The centering of the reference hole is to move and adjust the position of the main shaft 11 with respect to the reference hole 21 so that the main shaft 11 exists at a position where the axis of the main shaft 11 and the axis of the reference hole 21 coincide.
The centering of the reference hole 21 is performed by rotating the dial gauge 40 around the axis of the main shaft 11 together with the main shaft 11 in a state where the measuring element 42 (contact 42a) is rotated so as to contact the inner peripheral surface of the reference hole 21. Is done.
When the centering is completed, that is, when the dial gauge 40 is rotated around the axis of the main shaft 11 together with the main shaft 11, the contact 42a is in contact with the inner peripheral surface of the reference hole 21, and the dial When it is confirmed that the pointer 43a of the gauge 40 shows a constant value without shaking, it is estimated that the main shaft 11 exists at a position where the shaft of the main shaft 11 and the axis of the reference hole 21 coincide.

  (Iii) The position of the spindle 11 when the centering is completed in (ii) is set in the control unit 15 as the work origin (setting step: S23).

With the above configuration, if the machine vice 20 is leveled in (i) above, the attitude of the reference hole 21 is adjusted at the same time. Therefore, an operation for adjusting the attitude of the reference hole 21 is added. There is no need to do this, work efficiency can be improved, and the work origin can be set efficiently.
Moreover, since the attitude | position of the reference hole 21 is adjusted in said (i), centering can be performed accurately in said (ii). Thereby, the work origin can be set with high accuracy.

In the above (ii), the centering is performed by rotating the dial gauge 40 around the axis of the main shaft 11 while bringing the contact 42a of the dial gauge 40 into contact with the inner peripheral surface of the reference hole 21. It is confirmed that the dial gauge 40 is rotated in a state where the contact 42a is in contact with the inner peripheral surface of the reference hole 21 without swinging the pointer 43a, and the main shaft 11 is evenly spaced from the inner peripheral surface of the reference hole 21. Is done by ensuring that
As a result, the center of the reference hole 21 and the center of the main shaft 11 can be centered from point to point, and the centering accuracy is improved.

Further, the milling machine 2 does not require the work of bringing the contact 42a of the dial gauge 40 into contact with the work end surface 10a as shown in the above (3) when setting the work origin. For example, the work as shown in FIG. Even when machining the workpiece 17 in which the end surface 17a is not perpendicular to the plane and the workpiece end surface 17a and the axial direction of the main shaft 11 are not parallel to each other, an operation of bringing the contact 42a of the dial gauge 40 into contact with the workpiece 17 (workpiece end surface 17a). The workpiece origin can be set without going through.
As a result, the work origin can be accurately set without being affected by the shape of the work, which is excellent in versatility.
Note that the shapes of the contact surfaces of the fixed base 24 and the movable base 25 with the work are appropriately changed according to the shape of the work. When the work 17 is processed as shown in FIG. 11, the shape of the fixed base 24 is changed. The fixed base 24a and the movable base 25a in which the shape of the movable base 25 is changed are used.

A procedure for processing the workpiece 10 using the milling machine 2 will be described. It is assumed that the workpiece 10 is supported by the machine vice 20 in a state where the workpiece 10 is positioned by the positioning unit 50.
For example, as shown in FIG. 8, a position (de) separated from the workpiece end surface 10a by a dimension (D) in the (+) direction of the X axis and by a dimension (E) in the (+) direction of the Y axis from the workpiece end surface 10b. When machining the position), the operator sets the work origin with the center of the reference hole 21 as the origin in the control unit 15 according to the procedures (i) to (iii), and sets the work coordinate system in the input unit 14. The X-axis coordinate value (D + C) and the Y-axis coordinate value (E) may be input.
That is, as described above, since the positioning value is used when the workpiece 10 is fixed to the machine vise 20, the workpiece end surface 10b and the center of the reference hole 21 have the same Y-axis coordinate value. For the coordinate value of the Y axis, the dimension value of the design drawing or the like is directly input to the unit 14, and the value of the dimension value of the design drawing or the like plus the dimension (C) is input as the coordinate value of the X axis. .
At this time, since the workpiece origin can be set with high accuracy as described above, the workpiece 10 can be machined with high accuracy.

When the workpiece 10 is machined by specifying not only the X-axis coordinate value but also the Y-axis coordinate value, the above-described operations (1) to (5) are performed on the workpiece end surface 10a in the milling machine 1 of the first embodiment. After the operation, it is necessary to further perform the operations (3) to (5) for the workpiece end surface 10b.
On the other hand, in the milling machine 2 of the second embodiment, the above operations (i) to (iii) may be performed once, so that the workpiece 10 can be efficiently processed.

The machine vice 20 may have a positioning unit 60 in place of the positioning unit 50.
As shown in FIG. 12, the positioning portion 60 is a protrusion that is formed at the end of the fixed base 24 on the (−) direction side of the Y axis and protrudes in the (+) direction of the X axis.
The reference hole 21 is formed at a predetermined position on the outer periphery of the fixed base 24. Specifically, the distance from the center of the reference hole 21 to the end face on the (+) direction side of the X axis in the fixed base 24 is (C), and the distance to the positioning portion 60 in the Y axis direction is ( F).
When the work 10 is sandwiched and fixed between the fixed base 24 and the movable base 25, the work end surface 10b is brought into contact with the positioning portion 60.
For example, as shown in FIG. 12, when machining the de position, the operator sets the work origin with the center of the reference hole 21 as the origin in the control unit 15 in the procedure (i) to (iii). Then, the X-axis coordinate value (C + D) and the Y-axis coordinate value (EF) in the work coordinate system may be input to the input unit 14.

Further, as shown in FIG. 13, in the machine vice 20 of the milling machines 1 and 2, instead of the reference hole 21 of the fixed base 24, a reference pin (round bar) 70 whose outer diameter dimension is (A) from the fixed base 24. It is good also as a structure which protrudes.
In this case, the centering of the reference pin 70 is performed by the dial gauge 40 in the above (3) and (iii).

As shown in FIG. 14, the machine vice 20 of the milling machines 1 and 2 may have a cover portion 80 that covers the reference hole 21.
The cover 80 is configured to be detachable from the reference hole 21 of the fixed base 24 and configured to be able to close the reference hole 21.
A concave portion is formed in the outer periphery of the reference hole 21 in the fixed base 24, and the cover portion 80 is formed in a shape corresponding to the concave portion.
The reference hole 21 is closed by fitting the cover portion 80 into the recess and fixing the cover portion 80 to the fixed base 24 with screws 81 and 81.
When the reference hole 21 is used as shown in (2) or (ii) above, the cover 80 is removed and the reference hole 21 is left open. Closes the reference hole 21 with the cover 80.
With the configuration described above, chips and the like generated during processing of the workpiece 10 are scattered in the reference hole 21 so that the inner peripheral surface of the reference hole 21 is scratched, and the dimensional accuracy of the inner diameter of the reference hole 21 is deteriorated. Can be prevented.

1.2 Milling machine 10 Workpiece 11 Spindle 20 Machine vice 21 Reference hole 30 Stage 40 Dial gauge 42 Measuring element 50/60 Positioning part

Claims (7)

A spindle to which a tool for machining a workpiece can be attached;
A support member that has a reference hole formed at a predetermined position on the outer peripheral surface, has a positioning part that positions the work in a fixed position with respect to the reference hole, and supports the work in a state in which the work is positioned by the positioning part; ,
The support member is configured to be detachable, and a stage that supports the support member;
A workpiece origin setting method for a machine tool having
Attaching the support member to the stage, leveling the support member,
Adjusting the position of the main shaft relative to the reference hole, aligning the axis of the main shaft and the axis of the reference hole, aligning the main shaft with respect to the reference hole,
Set the position of the axis of the spindle at the completion of the centering as the workpiece origin;
How to set the workpiece origin for machine tools. The main shaft is configured to be capable of attaching a centering member having a measuring element supported rotatably.
The centering of the main shaft with respect to the reference hole is performed by rotating the centering member attached to the main shaft around the axis of the main shaft together with the main shaft in a state where the rotation center of the probe coincides with the axis of the main shaft. By rotating and adjusting the position of the main shaft relative to the reference hole so as to maintain a certain amount of rotation in a state where the probe is in contact with the inner peripheral surface of the reference hole when rotated.
The work origin setting method for a machine tool according to claim 1. A spindle capable of attaching a tool for machining a workpiece and a centering member having a measuring element supported rotatably;
A reference hole having a diameter of a predetermined dimension is formed at a predetermined position on the outer peripheral surface, and a support member that supports the workpiece;
The support member is configured to be detachable, and a stage that supports the support member;
A workpiece origin setting method for a machine tool having
Attaching the support member to the stage, leveling the support member,
When the centering member attached to the main shaft is rotated around the axis of the main shaft together with the main shaft in a state where the rotation center of the measuring member is coincident with the axis of the main shaft, While maintaining contact with the inner peripheral surface of the reference hole, the position of the spindle relative to the reference hole is adjusted so as to maintain a certain amount of rotation, and the axis of the spindle and the axis of the reference hole are Align the spindle with respect to the reference hole,
Bringing the probe into contact with the workpiece supported by the support member;
Moving the spindle until the turning amount of the measuring element in contact with the workpiece becomes equal to the turning amount of the measuring element in contact with the inner peripheral surface of the reference hole when the centering is completed;
On the side where the contact point between the measuring element and the workpiece exists in a direction perpendicular to the axial direction of the main shaft from the axis of the main shaft, a position separated from the size of the radius of the reference hole is set as a workpiece origin. To
How to set the workpiece origin for machine tools. A spindle to which a tool for machining a workpiece can be attached;
A support member that has a reference hole formed at a predetermined position on the outer peripheral surface, has a positioning part that positions the work in a fixed position with respect to the reference hole, and supports the work in a state in which the work is positioned by the positioning part; ,
The support member is configured to be detachable, and a stage that supports the support member;
With
Attaching the support member to the stage, leveling the support member,
Adjusting the position of the main shaft relative to the reference hole, aligning the axis of the main shaft and the axis of the reference hole, aligning the main shaft with respect to the reference hole,
Set the position of the axis of the spindle at the completion of the centering as the workpiece origin;
Machine Tools. The main shaft is configured to be capable of attaching a centering member having a measuring element supported rotatably.
The centering of the main shaft with respect to the reference hole is performed by rotating the centering member attached to the main shaft around the axis of the main shaft together with the main shaft in a state where the rotation center of the probe coincides with the axis of the main shaft. By rotating and adjusting the position of the main shaft relative to the reference hole so as to maintain a certain amount of rotation in a state where the probe is in contact with the inner peripheral surface of the reference hole when rotated.
The machine tool according to claim 4. A spindle capable of attaching a tool for machining a workpiece and a centering member having a measuring element supported rotatably;
A reference hole having a diameter of a predetermined dimension is formed at a predetermined position on the outer peripheral surface, and a support member that supports the workpiece;
The support member is configured to be detachable, and a stage that supports the support member;
With
Attaching the support member to the stage, leveling the support member,
When the centering member attached to the main shaft is rotated around the axis of the main shaft together with the main shaft in a state where the rotation center of the measuring member is coincident with the axis of the main shaft, While maintaining contact with the inner peripheral surface of the reference hole, the position of the spindle relative to the reference hole is adjusted so as to maintain a certain amount of rotation, and the axis of the spindle and the axis of the reference hole are Align the spindle with respect to the reference hole,
Bringing the probe into contact with the workpiece supported by the support member;
Moving the spindle until the turning amount of the measuring element in contact with the workpiece becomes equal to the turning amount of the measuring element in contact with the inner peripheral surface of the reference hole when the centering is completed;
On the side where the contact point between the measuring element and the workpiece exists in a direction perpendicular to the axial direction of the main shaft from the axis of the main shaft, a position separated from the size of the radius of the reference hole is set as a workpiece origin. To
Machine Tools. It is configured to be detachable from the reference hole of the support member, and has a cover portion that closes the reference hole.
The machine tool according to any one of claims 4 to 6.

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