JP5550383B2 - Control device - Google Patents

Description

The present invention relates to the control equipment.

  An NC (Numerical Control) device has a measurement function for measuring the length (tool length) of a tool attached to the machine tool, in addition to controlling the machine tool. In this measurement function, a command value is given and the tool is moved from the reference position to the measurement surface (in the measurement sensor), and when the tool arrives at the measurement surface, the machine is stopped at the same time. The difference from the coordinate value of the measured position is automatically calculated and used as the tool length. The measurement plane is defined by a plane that includes the measurement coordinates and is perpendicular to the measurement axis by designating the measurement axis and the measurement coordinates in a coordinate system having three axes orthogonal to each other.

  In addition, even for machine tools that cannot be mounted with the tool tilted directly with respect to the axial direction of the coordinate system, the tool is intended to cut in an oblique direction with respect to the axial direction, with a specific angle with respect to the axial direction. The tool may be attached to the machine tool through an angle holder having

  On the other hand, Patent Document 1 describes a touch sensor having a first contact surface orthogonal to the X axis or the Z axis and a second contact surface inclined by 45 ° with respect to the X axis and the Z axis. Yes. That is, the touch sensor detects the edge position error amount due to tool attachment, wear, or the like using the first contact surface. Subsequently, the touch sensor detects two Z-axis coordinate values positioned in the X-axis plus direction and the X-axis minus direction, respectively, when the blade edge comes into contact with the second contact surface by movement in the Z-axis minus direction. The main processor that has received the detection result obtains the X-axis lost motion amount based on the difference between the two Z-axis coordinate values, and adds the X-axis lost motion amount and the previously determined X-axis direction blade edge position error amount to X Obtain the tool compensation amount in the axial direction. Similarly, the tool correction amount in the Z-axis direction is obtained by adding the Z-axis lost motion amount and the cutting edge position error amount in the Z-axis direction. Thus, according to Patent Document 1, it is not necessary to perform tool cutting by performing trial cutting to measure a machining dimension error, and thus tool correction that enables high-precision machining in a short time is made possible.

JP-A-8-1405

  In the technique described in Patent Document 1, since the first contact surface is a surface extending in the Z-axis direction, the edge position error amount is detected in a state in which the position of the tool shifted from the blade edge is in contact with the first contact surface. There is a possibility. Thus, the cutting edge position error amount may not accurately represent the position of the cutting edge of the tool. Patent Document 1 describes that the amount of lost motion indicates a different value depending on the feed speed when positioning is performed, and discloses how the lost motion amount is related to the position of the blade edge. Absent. That is, according to the technique described in Patent Document 1, it is difficult to accurately obtain the length from the reference point to the blade edge (tool length) in the tool. That is, in the technique described in Patent Document 1, since the tool correction is performed without accurately obtaining the length from the reference point to the cutting edge in the tool, the accuracy of the tool correction is low.

The present invention was made in view of the above, an object of the present invention to provide a control equipment for a length from the reference point in the tool to the cutting edge can be accurately obtained.

  In order to solve the above-described problems and achieve the object, a control device according to one aspect of the present invention controls a machine tool in a coordinate system having three axes orthogonal to each other, and the central axis of a tool is A control device for controlling the tool attached to the machine tool so as to extend at an inclined angle with respect to one axis of a coordinate system, comprising a detection surface orthogonal to the central axis of the tool; A detection unit for detecting that the cutting edge of the tool is in contact with the detection surface; at least central coordinates of a reference plane extending along one axis of the coordinate system; a rotation center axis of the reference plane; and the reference By specifying the rotation angle of the plane in the coordinate system, the setting unit that sets the position information of the detection surface in the coordinate system, and the detection unit that the cutting edge of the tool is in contact with the detection surface Inspection A calculation unit that obtains a length from the reference point to the blade edge in the tool from the coordinates of the reference point in the tool at the time when the tool is done and the position information of the detection surface set by the setting unit. Features.

According to the present invention, since the set position information of the detected face in the coordinate system determining the length from the reference point in the tool to the cutting edge, Ru can be obtained accurately the length from the reference point to the cutting edge in the tool .

FIG. 1 is a diagram of an installation example of an inclined surface sensor and an angled tool. FIG. 2 is a configuration diagram of the NC apparatus showing the first embodiment. FIG. 3 is a flowchart of the tool length measurement processing unit in FIG. FIG. 4 is a flowchart of the drive control processing unit in FIG. FIG. 5 is an explanatory diagram of a method for calculating a correction amount from the tool center point to the tool edge point. FIG. 6 is an explanatory diagram of the measurement position and definition method of the measurement sensor before and after rotation. FIG. 7 is an explanatory diagram of tool length measurement using the measurement sensor in the comparative example.

  In this specification, the vector A is represented as ↑ A, and the vector AB is represented as ↑ (AB).

  Embodiments of a control device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
The configuration of the control device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration of a control device 1 according to the first embodiment. The control device 1 controls a machine tool (not shown) in a coordinate system (machine coordinate system) having an X axis, a Y axis, and a Z axis (three axes) orthogonal to each other. At the same time, the control device 1 controls the angled tool 301 attached to the machine tool via the angle holder H.

  The angled tool 301 is attached to the machine tool through an angle holder H at an angle α inclined with respect to the −X axis (one axis) direction. That is, the tool axis (center axis) 304 of the angled tool 301 extends in a direction (at an inclined angle α) that forms an angle α with respect to the −X axis direction.

  The control device 1 includes a measurement sensor (detection unit) 203 and an NC (Numerical Control) device 100.

  The measurement sensor 203 has an inclined stylus surface (detection surface) 202. The inclined stylus surface 202 is a surface orthogonal to the tool axis 304 of the angled tool 301. The measurement sensor 203 detects that the tool edge point 313 of the angled tool 301 is in contact with the inclined stylus surface 202 for the purpose of measuring the tool length (L306, L307) of the angled tool 301. The measurement sensor 203 supplies a signal indicating the detected result to the NC device 100.

  The NC device 100 sets measurement position information of the inclined stylus surface 202 as will be described later. When the tool edge point 313 of the angled tool 301 comes into contact with the inclined stylus surface 202, the NC device 100 moves from the inclined stylus surface 202 (tool edge point 313) to the tool center point (reference point) 305 of the angled tool 301. Correction amounts (length, tool length) L306 and L307 are calculated. The NC apparatus 100 performs an operation of adding the correction amounts (lengths) L308 and L309 from the tool correction reference point 312 to the tool center point 305 registered before the measurement, and the correction amounts L306 and L307, respectively. The quantities L310 and L311 are obtained and set. The tool correction reference point 312 is a point where (X, Z) = (0, 0) in the machine coordinate system when positioned at the origin of the machine coordinate system. The NC apparatus 100 can determine the coordinate position of the tool cutting edge point 313 in the machine coordinate system by adding the tool correction amounts L310 and L311 to the coordinate value of the tool correction reference point 312. The tool center point 305 is a reference point in the angled tool 301, and an arbitrary point located in the angled tool 301 on the tool axis 304 can be designated.

  Next, the configuration of the NC device 100 will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration of the NC apparatus according to the first embodiment. In FIG. 2, the configuration for measuring the tool length of the angled tool 301 in the NC apparatus is mainly shown.

  The NC device 100 includes a setting display unit 119, a setting display I / F 101, an external signal I / F 114, a control arithmetic unit 102, a storage unit 103, and a driving unit 104.

  The setting display unit 119 displays a GUI screen in addition to a predetermined screen on a display (not shown). The setting display unit 119 receives an instruction from the user via the GUI screen from a keyboard / mouse or the like, or from a touch panel sensor or the like. For example, the setting display unit 119 displays the center coordinates (measurement position) of a reference plane (for example, the pre-rotation measurement surface 81 shown in FIG. 6A) extending along one axis (for example, the X axis) of the machine coordinate system. 81a), the rotation center coordinate of the reference plane (for example, rotation center coordinate 82), the rotation center axis of the reference plane (for example, rotation center axis 83), and the rotation angle of the reference plane (for example, rotation angle θ). A setting instruction for accepting is received. The setting display unit 119 supplies information indicating a setting instruction to the setting display I / F 101. The setting display I / F 101 supplies information indicating the supplied setting instruction to the control arithmetic unit 102.

  The external signal I / F 114 receives the measurement position arrival signal 120 from the measurement sensor 203. The external signal I / F 114 supplies the received measurement position arrival signal 120 to the control arithmetic unit 102.

  The control arithmetic unit 102 includes a measurement position calculation processing unit (setting unit) 106, a tool length measurement processing unit (calculation unit) 105, and a drive control processing unit 107.

  The measurement position calculation processing unit 106 receives information indicating a setting instruction from the setting display I / F 101. The measurement position calculation processing unit 106 sets position information of the inclined stylus surface 202 in the machine coordinate system in accordance with the setting instruction. In other words, the measurement position calculation processing unit 106 determines the center coordinates (for example, the pre-rotation measurement surface 81 shown in FIG. 6A) extending along one axis (for example, the X axis) of the machine coordinate system. Coordinates of the measurement position 81a), rotation center coordinates of the reference plane (for example, rotation center coordinates 82), rotation center axis of the reference plane (for example, rotation center axis 83), and rotation angle of the reference plane (for example, rotation angle θ). Are set in the machine coordinate system, thereby setting the position information of the inclined stylus surface 202 in the machine coordinate system. The measurement position calculation processing unit 106 causes the storage unit 103 to store the set position information of the inclined stylus surface 202 (that is, the measurement position information 110).

  The tool length measurement processing unit 105 receives the measurement position arrival signal 120 from the external signal I / F 114. In response to the measurement position arrival signal 120, the tool length measurement processing unit 105 includes information indicating the coordinates of the tool center point (reference point) 305 in the machine coordinate system (that is, current position information 115) and position information of the inclined stylus surface 202. (That is, measurement position information 110) is acquired from the storage unit 103. The tool length measurement processing unit 105 obtains the length (tool length) from the tool center point (reference point) 305 to the tool edge point 313 in the angled tool 301 from the current position information 115 and the measured position information 110.

  The storage unit 103 stores post-rotation measurement position information 108, an axis stop request 113, current position information 115, an axis stop completion flag 109, and tool correction information 116. The post-rotation measurement position information 108 includes measurement position information 110, mode information 111, and tool center point position information 112. The current position information 115 is updated by the drive control processing unit 107 at least when the measurement sensor 203 detects that the tool edge point 313 of the angled tool 301 is in contact with the inclined stylus surface 202.

  The drive unit 104 includes an X-axis servo drive unit 117 and a Z-axis servo drive unit 118. The X-axis servo drive unit 117 drives, for example, the angled tool 301 in the direction along the X-axis via a motor (not shown) or a mechanical device (not shown). The Z-axis servo drive unit 118 drives, for example, the angled tool 301 in the direction along the Z-axis via a motor (not shown) or a mechanical device (not shown). The drive unit 104 may further include a Y-axis servo drive unit. In this case, the drive unit 104 can drive, for example, the angled tool 301 in the direction along the Y axis via a motor (not shown) or a mechanical device (not shown).

  Next, operation | movement of the control apparatus 1 is demonstrated using FIGS. FIG. 3 is a flowchart showing a flow of processing performed by the tool length measurement processing unit 105. FIG. 4 is a flowchart showing the flow of processing performed by the drive control processing unit 107. FIG. 5 shows a method for calculating the length (that is, the correction amount) from the center point to the cutting edge point in the tool. FIG. 6 shows the measurement position of the measurement sensor before the rotation (FIG. 6A) and after the rotation (FIG. 6B) and the definition method thereof. In the following, for the sake of simplicity, a lathe is provided with a measurement sensor having an inclined stylus surface rotated about the Y-axis direction as a rotation center axis, and an angled tool provided on the Z-X plane. An example of performing tool length measurement of an angled tool in a system machine tool will be described.

  First, the setting display unit 119 shown in FIG. 2 accepts a setting instruction on the condition that the tool length measurement mode recorded in the mode information 111 is off. The setting instruction is, for example, as shown in FIGS. 6A and 6B, the measurement axis 80 before rotation, the measurement position (center coordinate) 81a of the measurement surface (reference plane) 81 before rotation, the rotation center coordinate 82, the rotation. This is an instruction for designating the central axis 83 and the rotation angle θ. Specifically, the setting display unit 119 receives the following setting instruction.

  In FIG. 6A, ↑ (OP) is a measurement position before rotation which is a vector having the direction of the measurement axis 80 before rotation and a size R from the rotation center coordinate 82 to the measurement position 81a of the measurement surface 81 before rotation. Let it be a vector. For the measurement axis 80 before rotation, an axis perpendicular to the stylus surface (reference plane) to be rotated is set as any unit vector of orthogonal axes. In the first embodiment, the measurement axis 80 before rotation is assumed to be the Z axis, and the unit vector ↑ z = (0, 0, 1) of the Z axis is set.

  The measurement position 81a of the measurement surface (reference plane) 81 before rotation is the measurement axis 80 before rotation among the coordinates of the point where the stylus surface (reference plane) to be rotated and the orthogonal axis (X axis, Z axis) intersect. Set the coordinates of the selected axis (Z-axis) component. As the rotation center coordinates 82, position coordinates in the machine coordinate system are set.

  Further, ↑ (OP ′) in FIG. 6B has a direction in which the measurement axis 80 before rotation is rotated around the rotation center axis 83 by the rotation amount of the rotation angle θ with the rotation center coordinate 82 as the center, A post-rotation measurement position vector, which is a vector having a magnitude R from the rotation center coordinate 82 to the measurement position 85a of the post-rotation measurement surface 85, is used. The rotation center axis 83 is an axis that determines which axis the measurement surface 81 before rotation is rotated about, and is set as any unit vector of orthogonal axes. In the first embodiment, the rotation center axis 83 is assumed to be the Y axis, and the Y axis unit vector ↑ y = (0, 1, 0) is set.

  The rotation angle θ is a rotation amount by which the measurement surface 81 before rotation is rotated about the rotation center axis 83, and is an angle with a counterclockwise direction being positive when a plane perpendicular to the rotation center axis 83 is used as a reference. . The setting range is 0 ° <rotation angle θ <90 °. In the first embodiment, when the pre-rotation measurement position vector ↑ (OP) is rotated around the rotation center axis 83, that is, the Y-axis by the rotation angle θ, the post-rotation measurement surface (detection surface) 85 and the post-rotation measurement position A vector ↑ (OP ′) is obtained. The angle θ is in the relationship of α shown in FIG. 1 and θ = 180 ° −α.

  Then, the setting display unit 119 stores the setting instruction, that is, the set parameter in the setting display I / F 101.

  When the value is stored in the setting display I / F 101, the control arithmetic unit 102 calls the measurement position calculation processing unit 106. Then (setting step), the measurement position calculation processing unit 106 sets the measurement position rotation radius R of FIG. 6 to the axis set by the measurement axis 80 before rotation from the rotation center coordinate 82 to the measurement position 81a of the measurement surface 81 before rotation. Calculate by calculating the component distance. Subsequently, the measurement position calculation processing unit 106 generates a measurement position vector before rotation ↑ (OP) from the measurement axis 80 before rotation and the calculated measurement position rotation radius R. If the rotation center point is point O, the intersection of the measurement surface 81 before rotation and the straight line extending from the rotation center coordinate 82 in the direction of the measurement axis 80 before rotation is P, and the unit vector of the measurement axis 80 before rotation is ↑ z, measurement before rotation is performed. The position vector ↑ (OP) is obtained by the following equation.

      ↑ (OP) = R ↑ z ・ ・ ・ Formula 1

  Next, the measurement position calculation processing unit 106 rotates the pre-rotation measurement position vector ↑ (OP) by the rotation angle θ around the rotation center axis 83 set as described above, and the post-rotation measurement position vector ↑ (OP ′ ) Is generated. The angle θ is an angle with the counterclockwise rotation being positive with respect to the ZX plane, and indicates a rotation angle around the Y axis of the ZX plane. As shown in FIG. 6C, the intersection of the post-rotation measurement surface 85 and the post-rotation measurement axis is P ′, a perpendicular line is drawn from the point P ′ to the pre-rotation measurement axis 80, and the intersection is V. The post-measurement position vector ↑ (OP ′) is obtained by the following equation.

↑ (OP ') = ↑ (OV) + ↑ (VP')
= ↑ (OP) cos θ + (− (↑ (OP) × ↑ y) sin θ)
= (0,0, R) cos θ + (− (− R, 0,0) sin θ)
= (Rsinθ, 0, Rcosθ) ... Formula 2
In Equation 2, '×' is an outer product operator.

  In this way, the measurement position calculation processing unit (setting unit) 106 has the coordinates of the measurement position 81a of the measurement surface 81a before rotation, the rotation center coordinates 82 of the measurement surface 81 before rotation, and the rotation along the X axis of the machine coordinate system. By specifying the rotation center axis 83 of the pre-measurement surface 81 and the rotation angle θ of the pre-rotation measurement surface 81 in the machine coordinate system, they are orthogonal to the tool axis 304 of the angled tool 301 in the machine coordinate system. Measurement position information (↑ (OP ′) information) of the inclined stylus surface 202 is set. The measurement position calculation processing unit 106 stores the calculated post-rotation measurement position vector ↑ (OP ′) information as measurement position information 110 in the storage unit 103.

  Note that the information of the rotation center coordinate 82 may be obtained from the coordinate of the measurement position 81 a or the rotation center axis 83.

  Subsequently, the setting display unit 119 shown in FIG. 2 displays the tool correction reference point 312 to the tool center point 305 in FIG. 1 on condition that the tool length measurement mode recorded in the mode information 111 is off. The distance in the Z-axis direction (correction amount L308) and the distance in the X-axis direction (correction amount L309) are input (for example, a value measured in advance automatically). The set value input to the setting display unit 119 is supplied to the measurement position calculation processing unit 106 via the setting display I / F 101. The measurement position calculation processing unit 106 stores the supplied set value information in the storage unit 103 as the tool center point position information 112.

  When recognizing that the measurement position information 110 and the tool center point position information 112 necessary for measuring the tool length of the angled tool 301 are set, the control arithmetic unit 102 shown in FIG. To turn on the angled tool mounting mode indicating that the angled tool is being mounted, update the mode information 111 so that the mode information 111 indicates that the angled tool mounting mode is on, and store ( (For example, by overwriting).

  Further, when recognizing that the tool measurement mode is input to the NC device 100 by the machining program, parameter or external signal, the control arithmetic unit 102 turns on the tool length measuring mode indicating that the tool length is being measured. The mode information 111 is updated and stored in the storage unit 103 (for example, by overwriting) so that the mode information 111 indicates that the tool length measuring mode is on. The control arithmetic unit 102 calls the tool length measurement processing unit 105.

  The tool length measurement processing unit 105 periodically performs the processing of the flowchart shown in FIG. 3 until the tool length measurement mode is canceled. The tool length measurement processing unit 105 specifically performs the following processing.

  In step S51, the tool length measurement processing unit 105 reads out and refers to the mode information 111 from the storage unit 103, and determines whether or not the tool length measuring mode is on. If the tool length measurement mode is on (Yes in S51), the tool length measurement processing unit 105 proceeds to S52. If the tool length measurement mode is off (No in S51), the tool length measurement processing unit 105 ends the process. .

  In step S52 (detection step), the tool length measurement processing unit 105 reads the measurement position arrival signal 120 from the external signal I / F 114, and determines whether or not the measurement position arrival signal 120 is on. That is, if the measurement sensor 203 has not detected that the tool edge point 313 of the angled tool 301 is in contact with the inclined stylus surface 202, the measurement position arrival signal 120 is turned off and the tool length via the external signal I / F 114 is set. Supply to the measurement processing unit 105. If the measurement sensor 203 detects that the tool edge point 313 of the angled tool 301 is in contact with the inclined stylus surface 202, the measurement position arrival signal 120 is turned on and the tool length measurement processing unit 105 via the external signal I / F 114. To supply. If the measurement position arrival signal 120 is on (Yes in S52), the tool length measurement processing unit 105 advances the process to S53. If the measurement position arrival signal 120 is off (No in S52), the tool length measurement processing unit 105 ends the process. .

  In step S53, the tool length measurement processing unit 105 reads and refers to the axis stop completion flag 109 from the storage unit 103, and determines whether or not the axis stop completion flag is on. If the axis stop completion flag is on (Yes in S53), the tool length measurement processing unit 105 advances the process to S54. If the axis stop completion flag is off (No in S53), the tool length measurement processing unit 105 advances the process to S55.

  In step S54 (calculation step), after the axis stop by the drive control processing unit 107 is completed by the tool length measurement processing unit 105, the current position information 115 at the time of stop set by the drive control processing unit 107 and the measurement after rotation are performed. Using the position information 108, tool correction amounts (L307 and L306 shown in FIG. 1) are distributed and obtained for each orthogonal axis (X axis and Z axis). That is, the tool length measurement processing unit 105 determines the length from the tool center point (reference point) 305 to the tool edge point 313 (X shown in FIG. 1) in the angled tool 301 from the current position information 115 and the measured position information 110. A correction amount L307 in the axial direction and a correction amount L306 in the Z-axis direction) are obtained by distributing them for each orthogonal axis (X-axis, Z-axis).

  Here, the tool correction amount calculation method performed by the tool length measurement processing unit 105 in step S54 will be described in more detail with reference to FIG.

  FIG. 5 is a positional relationship diagram on the ZX plane when the angled tool 301 comes into contact with the inclined stylus surface 202 of the measurement sensor 203 and stops. When the pre-rotation measurement surface 71 in FIG. 5 is rotated around the rotation center coordinate O with the tool position rotation radius R and the rotation angle θ, the measurement surface after rotation is the measurement surface 72 after rotation (that is, the inclined stylus surface 202). ). An intersection with a perpendicular drawn from the rotation center coordinate O to the post-rotation measurement surface 72 is P ′, and the vector ↑ (OP ′) is the post-rotation measurement position vector calculated in the above setting step. The position of the tool center point 305 is defined as a point A, the intersection point between the position A of the tool center point 305 and the tool axis 73 orthogonal to the post-rotation measurement surface 72 (that is, the tool axis 304 shown in FIG. 1) is defined as M, and the rotation center coordinates. The intersection point of the straight line 74 passing through O and parallel to the Z axis and the tool axis 73 is B, a perpendicular line is drawn from the point A, which is the tool center point 305, to the straight line 74, and the intersection point is C. Let 74 be the intersection of 74.

  When the angled tool 301 and the inclined stylus surface 202 come into contact with each other, the position of the tool edge point 313 becomes the point M, so the tool length from the point A that is the tool center point 305 to the point M that is the tool edge point 313. The vector ↑ (AM) is obtained by the following equation.

↑ (AM) = ↑ (OM)-↑ (OA) ... Formula 3
If the coordinates of the point A that is the tool center point 305 are (x _A , z _A ) and the coordinates of the rotation center coordinate O are (x _O , z _O ), ↑ (OA) is the point of the point A that is the tool center point 305. From the difference between the coordinate and the coordinate of the rotation center coordinate O, the following equation is obtained.

↑ (OA) = (x _A −x _O , z _A −z _O ) Equation 4

  Further, ↑ (OM) is obtained by the following equation.

↑ (OM) = ↑ (OB) + ↑ (BM)
= (↑ (OC) + ↑ (CB)) + ↑ (BM) Equation 5
In order to calculate ↑ (OM), ↑ (OC), ↑ (CB) and ↑ (BM) are calculated separately.

  First, ↑ (OC) is obtained by the following equation from FIG.

↑ (OC) = (0, z _A −z _O ) Equation 6
From FIG. 5, ↑ (CB) is an orthogonal projection of ↑ (AB) onto the measurement axis ↑ z before rotation.

↑ (AB) = (x _O −x _A , | x _A −x _O | / (tan θ))
It becomes. When ↑ z = (0,1) and 0 ° <θ <90 °, ↑ (CB) is obtained by the following equation.

↑ (CB) = (↑ (AB) ・ ↑ z) / | ↑ z | ²・ ↑ z
= | ↑ (AB) || ↑ z | cos (180 ° −θ) / | ↑ z | ² · ↑ z
= (| X _A −x _O | / (sin θ) * 1 * (− cos θ)) / 1 · ↑ z
= (0, − | x _A −x _O | / (tan θ)) Equation 7
In Equation 7, '·' is an inner product operator and '*' is a scalar product operator.

  Next, in order to calculate ↑ (BM), it is proved that the triangle P′OQ and the triangle MBQ in FIG. 5 are similar. Since the triangle P′OQ and the triangle MBQ have a common angle ∠P′QO and ∠OP′Q = ∠BMC = 90 °, the corresponding two angles are equal, so the triangle P′OQ and the triangle MBQ are It is similar. Here, since ↑ (BM) is parallel to the post-rotation measurement position vector ↑ (OP ′), the following equation is established.

↑ (BM) = | ↑ (BM) | / | ↑ (OP ') | * ↑ (OP') ... Formula 8
Since the triangle P'OQ and the triangle MBQ are similar,

| ↑ (OP ') |: | ↑ (OQ) | = | ↑ (BM) |: | ↑ (BQ) |
Therefore, the size of ↑ (BM) is obtained by the following equation.

      | ↑ (BM) | / | ↑ (OP ') | = | ↑ (BQ) | / | ↑ (OQ) |

= (| ↑ (OQ) − ↑ (OB) |) / | ↑ (OQ) |
Here, from Equation 6 and Equation 7,

      ↑ (OB) = ↑ (OB) + ↑ (CB)

= (0, z _A −z _O ) + (0, − | x _A −x _O | / (tan θ))

= (0, (z _A −z _O ) − | x _A −x _O | / (tan θ)) Equation 10
It is. From FIG.

↑ (OQ) = (0, R / (cos θ))
So,

| ↑ (OQ) | = R / (cosθ)
Is used, Equation 9 is

| ↑ (BM) | / | ↑ (OP ′) | = (| R / (cos θ) − (z _A −z _O ) + | x _A −x _O | / (tan θ) |) / (R / (cos θ ))
Can be converted to

  Therefore, substituting Equation 9 and Equation 2 into Equation 8,

↑ (BM) = ((| R / (cos θ) − (z _A −z _O ) + | x _A −x _O | / (tan θ) |) / (R / (cos θ))) * ↑ (OP ′)

= (| R / (cos θ) − (z _A −z _O ) + | x _A −x _O | / (tan θ) |) (cos ² θ, cos θ sin θ)
It becomes. When Expression 10 is substituted into Expression 5, ↑ (OM) is obtained by the following expression.

↑ (OM) = (0, (z _A −z _O ) − | x _A −x _O | / (tan θ)) + ↑ (BM) Equation 12
By substituting Equations 12 and 4 into Equation 3, the tool length vector ↑ (AM) from the point A as the tool center point 305 to the point M as the tool edge point 313 can be obtained by the following equation.

↑ (AM) = ((0, (z _A −z _O ) − | x _A −x _O | / (tan θ)) + ↑ (BM)) − (x _A −x _O , z _A −z _O )

= (− (X _A −x _O ), − | x _A −x _O | / (tan θ)) + ↑ (BM)

= (− (X _A −x _O ) + | R / (cos θ) − (z _A −z _O ) + | x _A −x _O | / (tan θ) | cos ² θ, − | x _A −x _O | / (Tan θ) + | R / (cos θ) − (z _A −z _O ) + | x _A −x _O | / (tan θ) | cos θsin θ)
The length (correction amount) Zc in the Z-axis direction and the length (correction amount) Xc in the X-axis direction from the tool center point 305 (point A) to the tool edge point 313 (point M) calculated by Expression 13 are: This corresponds to the correction amount L306 in the Z-axis direction and the correction amount L307 in the X-axis direction in FIG.

  In step S54 shown in FIG. 3, the tool length measurement processing unit 105 reads the tool center point position information 112. The tool length measurement processing unit 105 calculates the tool from the correction amount L308 (see FIG. 1) in the Z-axis direction from the tool correction reference point 312 to the tool center point 305, and the tool center point 305 (point A) calculated by Expression 13. The correction amount L306 (see FIG. 1) in the Z-axis direction up to the cutting edge point 313 (point M) is added. As a result, the tool length measurement processing unit 105 calculates a correction amount L310 (see FIG. 1) in the Z-axis direction from the tool correction reference point 312 to the tool cutting edge point 313.

  Similarly, the tool length measurement processing unit 105 includes a correction amount L309 (see FIG. 1) in the X-axis direction from the tool correction reference point 312 to the tool center point 305, and the tool center point 305 (point A) calculated by Expression 13. ) To the tool cutting edge point 313 (point M) and a correction amount L307 (see FIG. 1) in the X-axis direction. Thereby, the tool length measurement processing unit 105 calculates the correction amount L311 (see FIG. 1) in the X-axis direction from the tool correction reference point 312 to the tool cutting edge point 313.

  The tool length measurement processing unit 105 stores a set of the correction amount L310 in the Z-axis direction and the correction amount L311 in the X-axis direction as tool correction information 116 in the storage unit 103 (see FIG. 2).

  In step S55 shown in FIG. 3, the tool length measurement processing unit 105 turns on the axis stop request in order to stop the movement of the axis by the drive control processing unit 107, and the axis stop request 113 indicates that the axis stop request is on. Thus, the axis stop request 113 is updated and stored in the storage unit 103 (for example, by overwriting). Then, the tool length measurement processing unit 105 ends the tool length measurement process.

  Next, when recognizing that the axis stop request is turned on, the control arithmetic unit 102 shown in FIG. 2 calls the drive control processing unit 107. The drive control processing unit 107 periodically performs the processing of the flowchart shown in FIG. Specifically, the drive control processing unit 107 performs the following processing.

  In step S61, the drive control processing unit 107 reads and refers to the axis stop request 113 from the storage unit 103, and determines whether or not the axis stop request is on. If the axis stop request is on (Yes in S61), the drive control processing unit 107 advances the process to S62. If the axis stop request is off (No in S61), the drive control processing unit 107 ends the process.

  In step S62, the drive control processing unit 107 outputs an axis movement stop command to the X-axis servo drive unit 117 and the Z-axis servo drive unit 118, respectively. As a result, the X-axis servo drive unit 117 and the Z-axis servo drive unit 118 each stop moving the axis. At this time, the X-axis servo drive unit 117 and the Z-axis servo drive unit 118 each hold FB (feedback) position information of the stop position.

  In step S <b> 63, the drive control processing unit 107 reads out FB (feedback) position information of the stop position from the X-axis servo drive unit 117 and the Z-axis servo drive unit 118. The drive control processing unit 107 stores the read FB (feedback) position information of the stop position in the storage unit 103 as current position information 115.

  In step S64, the drive control processing unit 107 turns on the axis stop completion flag, updates the axis stop completion flag 109 so that the axis stop completion flag 109 indicates ON of the axis stop completion flag, and stores it in the storage unit 103 (for example, Memorize). Then, the drive control processing unit 107 ends the drive control process.

  Here, suppose that the angled tool 301 is brought into contact with the stylus surface 204 of the measurement sensor 203 in order to measure the tool length of the angled tool 301, as shown in FIG. In this case, since the stylus surface 204 is a surface extending in the Z-axis direction, the tool edge point 313 of the angled tool 301 is in a state where the position 314 shifted from the tool edge point 313 of the angled tool 301 is in contact with the stylus surface 204. It will be detected by recognizing that it has touched the stylus surface 204. In this case, it becomes difficult to accurately obtain the length (tool length) from the tool center point 305 to the tool edge point 313 in the angled tool 301.

  On the other hand, in the first embodiment, information on the measurement position (detection surface) of a measurement sensor having an inclined stylus surface is defined in the machine coordinate system.

  Specifically, after setting the measurement surface (reference plane) before rotation by specifying the measurement axis and measurement coordinates, the rotation center coordinates of the measurement surface, the rotation center axis of the measurement surface, and the rotation angle information of the measurement surface Is set from the NC device, the measurement surface is rotated by the rotation angle information around the rotation center axis. At that time, the rotation angle information is set so that the tool axis of the angled tool and the measurement surface (detection surface) after rotation intersect perpendicularly. Further, the center point information of the angled tool is set by setting the correction amount up to the tool center point 305 of the angled tool with reference to the tool attachment center point (tool correction reference point 312) of the angle holder.

  Next, the angled tool is fed in the tool axis direction, and when the inclined stylus surface of the measurement sensor comes into contact with the tool edge point of the angled tool, the measurement sensor outputs a measurement position arrival signal to the NC device. When the measurement position arrival signal is input to the NC unit, the distance from the tool center point of the angled tool to the measurement surface (tool edge point) is determined for each orthogonal axis (X axis, Z axis) based on the rotation angle information. Calculated as the distributed correction amounts (L307 and L306 shown in FIG. 1).

  In this way, the information from the measurement position (detection surface) of a measurement sensor having an inclined stylus surface is defined (set) in the machine coordinate system, and the length from the tool center point to the tool edge point in an angled tool is obtained. The length from the tool center point 305 to the tool edge point 313 in the angled tool can be accurately obtained. Then, correction amounts (L311 and L310) obtained by adding the calculated correction amounts and the correction amounts (L309 and L308 shown in FIG. 1) from the tool correction reference point 312 to the tool center point 305 of the angle holder are added. Use to correct the tool edge position. Thereby, since the length from the tool center point 305 to the tool edge point 313 in the angled tool is accurately obtained and the tool correction is performed, the accuracy of the tool correction can be improved.

  Further, according to the first embodiment, it is not necessary to measure and set the tool length of an angled tool attached to an angle holder having a specific angle, leading to a reduction in setup time.

As described above, the control equipment according to the present invention are useful for tool compensation, particularly suitable for correction of the tool attached to the machine tool at an angle tilted with respect to the axial direction of the coordinate system.

71 Measurement surface before rotation 72 Measurement surface after rotation 73 Tool axis 74 Straight line passing through rotation center coordinates and parallel to Z axis 80 Measurement axis before rotation 81 Measurement surface before rotation 82 Center of rotation coordinates 83 Center of rotation axis 84 Angle of rotation 85 Measurement after rotation Surface 100 NC device 101 Setting display I / F
102 Control processing unit 103 Storage unit 104 Drive unit 105 Tool length measurement processing unit 106 Measurement position calculation processing unit 107 Drive control processing unit 108 Measurement position information after rotation 109 Axis stop completion flag 110 Measurement position information 111 Mode information 112 Tool center point Position information 113 Axis stop request 114 External signal I / F
115 Current position information 116 Tool correction information 117 X-axis servo drive unit 118 Z-axis servo drive unit 119 Setting display unit 120 Measurement position arrival signal 202 Inclined stylus surface 203 Measurement sensor 301 Tool with angle 304 Tool axis 305 Tool center point 312 Tool correction Reference point 313 Tool edge point L306 Z-axis correction amount from tool center point to tool edge point L307 X-axis correction amount from tool center point to tool edge point L308 Z-axis correction amount from tool correction point to tool center point L309 X-axis correction amount from tool correction reference point to tool center point L310 Z-axis correction amount from tool correction reference point to tool edge point L311 X-axis correction amount from tool correction reference point to tool edge point

Claims (2)

The machine tool is controlled in a coordinate system having XYZ axes orthogonal to each other, and the central axis of the tool is parallel to the ZX plane of the coordinate system and extends at an angle inclined with respect to the Z axis. A control device for controlling the tool attached to the machine tool,
A detection unit having a detection surface orthogonal to the central axis of the tool, and detecting that a cutting edge of the tool is in contact with the detection surface;
The position of the rotation center point O set on a straight line perpendicular to the detection surface, the distance R between the rotation center point O and the detection surface, and the detection surface until the detection surface is perpendicular to the Z axis. A setting unit that sets a rotation angle θ required to rotate the rotation center point O about the axis extending in the Y-axis direction as position information of the detection surface in the coordinate system;
The coordinates of the tool center point located on the central axis of the tool when the detection unit detects that the cutting edge of the tool is in contact with the detection surface, and the position of the detection surface set by the setting unit From the information, a calculation unit for obtaining a length from the tool center point to the cutting edge,
A control device comprising: The machine tool is controlled in a coordinate system having XYZ axes orthogonal to each other, and the central axis of the tool is parallel to the ZX plane of the coordinate system and extends at an angle inclined with respect to the Z axis. A control device for controlling the tool attached to the machine tool,
A detection unit having a detection surface orthogonal to the central axis of the tool, and detecting that a cutting edge of the tool is in contact with the detection surface;
The position of the rotation center point O is set to a straight line perpendicular on the detection surface, perpendicularly the detection surface to the SL before the rotation center point O around an axis extending in the Y-axis direction detection plane the Z axis a rotation angle θ required to rotate until the rotation only before Symbol rotation angle θ of the detection surface the detection surface so as to be perpendicular to the Z axis about an axis extending in the Y-axis direction from the rotation center point O A setting unit that sets the position of the detection surface as the position information of the detection surface in the coordinate system,
The coordinates of the tool center point located on the central axis of the tool when the detection unit detects that the cutting edge of the tool is in contact with the detection surface, and the position of the detection surface set by the setting unit From the information, a calculation unit for obtaining a length from the tool center point to the cutting edge,
A control device comprising:

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