JP5199209B2 - Numerical control device for table turning 5-axis machine - Google Patents

Description

  The present invention provides a five-axis machining machine for machining a workpiece (hereinafter referred to as “workpiece”) attached to a table with three linear axes and at least two rotary axes including a table turning rotary axis. The present invention relates to a numerical control device to be controlled.

  In recent years, as disclosed in, for example, Patent Document 1, the movement of the tool tip position on a coordinate system defined on a table (hereinafter referred to as “table coordinate system”) is commanded by a program. Processing has become normal. In this case, if the table coordinate system position is defined according to the workpiece position, the same workpiece can be machined with the same program command without depending on the table coordinate system position, that is, without depending on the workpiece position.

Japanese Patent Laid-Open No. 2003-195917

  If the table coordinate system is defined according to the workpiece position as described in the background art, the same workpiece can be machined with the same program command without depending on the workpiece position. The position of the workpiece, that is, the position of the table coordinate system is important. This will be described with reference to an example in which a workpiece is machined by a program command on the table coordinate system in the table turning 5-axis machine with the machine configuration shown in FIG. The rotary axes 2 of the table turning 5-axis machine shown in FIG. 1 are the A axis (rotating axis for tilting the table) and the C axis (axis for turning the table), but the A, B axes, There are also combinations of B and C axes.

  FIG. 2 shows that the workpiece 3 is placed on the table 1 of the table turning five-axis machine shown in FIG. Here, when the workpiece 3 is machined from the point P1 to the point P2 of the workpiece 3 together with the command of A = 0 to A = −90.0 on the table coordinate system by the table turning 5-axis processing machine, the table 1 Changes its posture as shown in FIGS. And the workpiece | work 3 is processed with the tool 2 with which the table turning 5-axis processing machine was mounted | worn. A broken line arrow 5 shown in FIG. 3 is a movement path of the tool tip point of the tool 2 when the workpiece 3 is machined from the point P1 to the point P2.

  Next, as shown in FIG. 4, it is assumed that the jig 4 is mounted on the table 1 of the table turning 5-axis processing machine shown in FIG. 1 and the workpiece 3 is placed on the jig 4. . In this case, when the workpiece 3 is machined from the point P1 to the point P2, the table 1, the tool 2, the workpiece 3, and the jig 4 operate from the state shown in FIG. 4 to the state shown in FIG. A broken line arrow 6 shown in FIG. 5 indicates a tool tip point of the tool 2 when the jig 4 is mounted on the table 1 and the work 3 is placed on the jig 4 and the work 3 is machined from the point P1 to the point P2. It is a travel route.

  When the jig 4 is attached to the table 1 and when it is not attached, the movement path of the tool 2 shown in FIGS. 3 and 5 is related to the table turning center and the tool tip point of the tool 2. If attention is paid to the illustration only, it will be as shown in FIG. As can be seen from FIG. 6, even when the same workpiece 3 is machined by the same machining program, the linear axis movement amount of the tool tip point depends on the position of the workpiece 3 (here, the table coordinate system origin position) ( The linear axis movement distance is different. In the case of the above example, the tool tip from the state shown in FIG. 2 to the state shown in FIG. 3 is compared with the amount of linear axis movement of the tool tip point from the state shown in FIG. 4 to the state shown in FIG. The amount of linear movement of the point is smaller.

  Assuming that the combined speed of the X, Y, and Z axes is a constant speed according to the allowable speed of each of the X, Y, and Z axes, which are linear axes, the tool tip changes from the state shown in FIG. 2 to the state shown in FIG. Since the processing time is shorter when the point is moved than when the tool tip point is moved from the state shown in FIG. 4 to the state shown in FIG. Moreover, since the amount of linear axis movement is small, it is also energy saving processing. The difference in the amount of linear axis movement is generated from Equation 1 when roughly described. That is, when the tool tip point moves from the state shown in FIG. 2 to the state shown in FIG. 3, even if the “rotation axis movement amount” is the same, the “position between the tool tip point and the table turning center” Since the “distance” is short, the linear axis movement amount is smaller than the tool tip point moves from the state shown in FIG. 4 to the state shown in FIG. 5.

  Since the rotation axis movement amount is specified by the machining program, it cannot be changed. On the other hand, by shifting the position of the tool tip point, the tool tip point can be brought close to or coincident with the table turning center of the table constituting the table turning 5-axis processing machine. However, in the past, the machining is performed without considering the relationship between the tool tip point and the table turning center, that is, where the position of the workpiece is on the turning table of the table turning 5-axis processing machine. Was done. For example, in the technique disclosed in Patent Document 1, the work coordinate system ΣW is stored to become a table coordinate system. However, the technical idea of “desired position of the origin position of the table coordinate system” is disclosed in Patent Document 1 as well. It has not been done. Therefore, Patent Document 1 does not disclose or suggest the technical idea of reducing the linear axis movement amount generated from “the distance between the position of the tool tip point and the table turning center” and “the rotational axis movement amount”.

  Accordingly, an object of the present invention is to reduce the amount of linear axis movement based on the “distance between the position of the tool tip point and the table turning center” and the “movement amount of the rotary axis”, and to perform machining in a shorter time and with less energy saving. It is to provide a numerical control device for a table turning 5-axis processing machine capable of performing the above. More specifically, the object of the present invention is a position on the designated program coordinate system, and if the position is moved to the table turning center, “the distance between the position of the tool tip point and the table turning center” and “ It is possible to obtain the recommended machining center position where the linear axis movement amount based on the “rotary axis movement amount” is as small as possible, and to find the recommended machining position change amount to make the recommended machining center position coincide with or close to the table turning center. Is to provide a numerical control device for a simple table turning 5-axis machine.

  The invention according to claim 1 of the present application commands a tool direction and a linear axis position on a designated program coordinate system, and includes three linear axes and at least one rotary axis for table rotation with respect to a workpiece attached to the table. A numerical control device for a table turning five-axis machine that controls a table turning five-axis machine working with two rotation axes, which is a position on the designated program coordinate system and is moved to the table turning center of the table. For example, a recommended machining center position calculating means for obtaining a recommended machining center position where the movement amount of the linear axis is as small as possible, and the recommended machining center position so that the recommended machining center position coincides with the table turning center, or the recommended machining center And a recommended machining position change amount calculating means for obtaining a recommended machining position change amount so that the position approaches the table turning center. A numerical controller table pivot 5 axis machine.

The invention according to claim 2 is that the specified program coordinate system is a table coordinate system defined on a table, and the recommended machining position change amount is a recommended table coordinate system origin position, a recommended table coordinate system origin shift amount, or The numerical control device for a table turning five-axis machine tool according to claim 1, wherein the numerical value is a recommended linear axis position shift amount with respect to a command linear axis position in the command program.
The invention according to claim 3 is that the specified program coordinate system is a workpiece coordinate system shifted from a machine coordinate system, and the recommended machining position change amount is a recommended workpiece coordinate system origin position, a recommended workpiece coordinate system origin shift amount, or The numerical control device for a table turning five-axis machine tool according to claim 1, wherein the numerical value is a recommended linear axis position shift amount with respect to a command linear axis position in the command program.

The invention according to claim 4 is characterized in that the recommended machining center position calculation means is obtained by performing a weighted average calculation using the linear axis command position and the rotation axis command position in a command program. 3 is a numerical control device for a table turning 5-axis machining apparatus according to any one of 3;
The invention according to claim 5 is characterized in that the recommended machining center position calculation means obtains the calculation by the least square method using the linear axis command position and the rotation axis command position in the command program. 3 is a numerical control device for a table turning 5-axis machining apparatus according to any one of 3;

The invention according to claim 6 is characterized in that the recommended machining center position calculation means obtains by performing calculation by weighted average using a linear axis interpolation position and a rotation axis interpolation position for each interpolation cycle. 3 is a numerical control device for a table turning 5-axis machining apparatus according to any one of 3;
The invention according to claim 7 is characterized in that the recommended machining center position calculation means obtains the calculation by the least square method using the linear axis interpolation position and the rotation axis interpolation position for each interpolation cycle. It is a numerical control apparatus for table turning 5 axis | shaft processing machines as described in any one of -3.

The invention according to claim 8 of the present application, before Symbol recommended processing position change amount calculating means, the linear shaft working area linear axis commanded sequence of points are set at the maximum position and the minimum position of the processable linear axes in the command program The recommended machining position change amount is calculated so that the recommended machining center position coincides with the table turning center, or the recommended machining center position approaches the table turning center within an inner range. It is a numerical control apparatus for table turning 5 axis | shafts processing machines as described in any one of Claims 1-7.

The invention according to claim 9 is characterized in that the recommended processing center position calculating means operates while processing a workpiece by the table turning 5-axis processing machine. This is a numerical control device for a table turning 5-axis machine.
The invention according to claim 10 is characterized in that the recommended machining center position calculation means operates by simulation without machining the workpiece by the table turning 5-axis machining apparatus. It is a numerical control apparatus for table turning 5 axis | shaft processing machines of description.

According to an eleventh aspect of the invention, the two rotary shafts of the table turning five-axis machine are such that one of them is a rotary shaft that turns the table and the other one is a rotary shaft that tilts the table. It is a numerical control apparatus for table turning 5 axis | shafts processing machines as described in any one of Claims 1-10 characterized by the above-mentioned.
According to a twelfth aspect of the present invention, the two rotary shafts of the table turning five-axis machine are such that one of them is a rotary shaft that turns the table and the other one is a rotary shaft that tilts the tool head. It is a numerical control apparatus for table turning 5 axis | shafts processing machines as described in any one of Claims 1-10 characterized by these.

  The present invention makes it possible to reduce the amount of linear axis movement based on “the distance between the position of the tool tip and the table turning center” and “the amount of movement of the rotation axis”, and to perform processing with shorter time and more energy saving. A numerical control device for a turning 5-axis machine can be provided. More specifically, the present invention is a position on a command program coordinate system, and if the position is moved to the table turning center, “the tool tip point In order to obtain a recommended machining center position where the linear axis movement amount is as small as possible based on “distance between position and table turning center” and “rotation axis movement amount”, and to make the recommended machining center position coincide with or close to the table turning center It is possible to provide a numerical control device for a table turning 5-axis processing machine capable of obtaining the recommended machining position change amount.

It is the schematic explaining the structure of the table turning 5 axis | shaft processing machine which has two rotating shafts of A and C axes. It is a figure explaining processing a workpiece | work from A = 0 toward the point P2 from the point P1 on a table coordinate system. It is a figure explaining that it became A = -90.0 and processing of a work progressed to point P2. It is a figure explaining processing from A = 0 toward point P2 from point P1 on a table coordinate system when a jig is attached on a table. It is a figure explaining that it became A = -90.0 when a jig was attached on a table, and processing of a work progressed to point P2. It is a figure explaining the relationship between a table turning center and a tool front-end | tip point. It is a figure explaining a program command. It is a figure explaining the program command commanded with a tool direction vector. It is a figure explaining the relationship of each vector when a jig | tool is mounted on the table. A state of being rotated a _n is a view from the + X side in Fig. 9 (to a _n rotate A axis as the table rotates -a _n.). It is a figure explaining how to obtain the recommended machining center position Pa. It is a diagram for explaining that the recommended processing center position Pa relative to the commanded sequence of points Pl ₀ through PL _ne is obtained. It is a figure which shows a processable area | region paying attention only to the maximum command position and minimum command position of each linear axis. It is a figure explaining the recommended process center position Pa approaching the table turning center. It is a figure explaining that a recommended processing center position calculation means and a recommended processing position change amount calculation means are called from a program analysis means and perform processing in a numerical control device. It is a flowchart which shows the algorithm of the process which calculates | requires a recommended process center position and a recommended process position change amount using a least squares method. It is a figure explaining that a recommended processing center position calculation means and a recommended processing position change amount calculation means are called from an interpolation means and perform processing in a numerical controller. It is a figure explaining that even when commanded in the work coordinate system, the recommended machining center position and the recommended machining position change amount can be calculated. One axis is a schematic diagram of a 5-axis processing machine which is a rotary axis for turning a table and the other axis is a rotary axis for tilting a tool head. It is a figure explaining the movement path | route of the tool front-end | tip point at the time of processing it turning and putting a workpiece | work near the table turning center. It is a figure explaining the movement path | route of the tool front-end | tip point at the time of processing it turning and putting a workpiece | work away from a table turning center. It is a figure explaining the structure of the table turning 5 axis | shaft processing machine with the turning table generally called a "trunion".

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the structure with a similar function is demonstrated using the same code | symbol.
A feature of the numerical control device for a table turning 5-axis machining apparatus according to the present invention is a numerical control device for a table turning 5-axis processing machine for controlling a table turning 5-axis processing machine to be machined, at a position on a designated program coordinate system. The recommended machining center position calculating means for obtaining a recommended machining center position where the movement amount of the linear axis becomes as small as possible when the table moves to the table turning center, and the recommended machining center position matches the table turning center. Or a recommended machining position change amount calculation means for obtaining a recommended machining position change amount so that the recommended machining center position approaches the table turning center.

First, how to obtain the recommended machining center position will be described.
(1) Calculation of recommended machining center position (1-1) When the command program coordinate system is a table coordinate system (1-1-1) When calculating the linear axis movement amount in units of blocks As described above, the machining program The command program coordinate system commanded by the command program is a table coordinate system, and the method of obtaining the recommended machining center position will be described taking as an example the case of calculating the linear axis movement amount in block units. It is assumed that the program command is commanded as shown in FIG. FIG. 7 shows an example of a program in which the tool direction is commanded by the rotation axis position (A, C). On the other hand, as shown in FIG. 8, the tool direction can be commanded by a tool direction vector (I, J, K). Here, G43.5 indicates a tool tip point command for commanding the tool direction with a tool direction vector. However, since the rotation axis position corresponding to the command in the tool direction vector can be easily converted into the command in the tool direction at the rotation axis position by the calculation of Formula 2, this will be described with reference to the program example of FIG. The axial direction is the A-axis origin direction, and the X-axis direction is the C-axis origin direction.)

  In FIG. 7, G43.4 is a tool tip point control start command, and the work coordinate system in this block is stored as a table coordinate system, and the table coordinate system turns with the rotation of the rotary shaft. X, Y, and Z commands in subsequent blocks are commanded as the position of the tool tip point on the table coordinate system. The X, Y, Z, A, and C commands are absolute commands. H1 is a tool length correction number. F is the command speed of the tool tip point. However, when the speed of the control point (machine movement position, machine coordinate position, see FIG. 9) exceeds the allowable speed by the program command, the speed of the control point is clamped at the allowable speed. G49 is a command to end the tool tip point control.

A vector and a matrix used for calculating the recommended machining center position are defined as follows. Pl _n (x _n , y _n , z _n ) ^T is a vector of X, Y, and Z axis command positions of Nn _n blocks. Pl ₀ is a vector of X, Y, and Z axis command positions of the block of G43.4. Vo (Vox, Voy, Voz) ^T is the initial position of the X, Y, Z axis table coordinate system origin, that is, the vector of the table coordinate system origin position that stores the work coordinate system as the table coordinate system in the G43.4 block. It is. Pc (Pcx, Pcy, Pcz) ^T is a vector of the machine coordinate position of the table turning center (the intersection of the A-axis rotation center and the C-axis rotation center). This is set as a separate parameter. Vh (Vhx, Vhy, Vhz) ^T is a tool length correction vector. When the tool faces the Z axis, Vh = (0, 0, h). Here, the element h of the tool length correction vector Vh is a tool length correction amount.

FIG. 9 is a diagram for explaining the relationship between the vectors when a jig is placed on the table. As shown in FIG. 9, it is assumed that the jig 4 is placed on the table 1. Each vector has a relationship as shown in FIG. In the figure, the subscript “ _n ” is not shown for the sake of simplicity in the notation of each vector.

Next, a rotation matrix based on the A-axis position and a rotation matrix based on the C-axis position will be described.
RA _n shown in Equation 3 is a rotation matrix based on the A-axis position (see FIGS. 9 and 10).

RC _n shown in the equation 4 is a rotation matrix based on the C-axis position (see FIG. 9).

Pl _n to the corresponding control point machine coordinate position vector _{Pm n (Pm n x, Pm} n y, Pm n z) is ^T, the Pc against as equation (5) (Vo + Pl _n) (see FIG. 9) c _n centered performs rotation of a _n, obtained by adding the tool length compensation Vh. Incidentally, c _n is absolute command position in the C-axis (rotation movement position), a _n is the absolute command position of the A-axis (the rotational movement position).

Here, it is shown in Figure 10 To illustrate the state of being rotated a _n in the A-axis position from the + X side.

Equation (5) of the last Pc and Vh is a binomial is excluded because not directly related to the linear axis motion amount generated by the rotation shaft movement amount, Nn _n-1 the end of the block and Nn _n the end of the block as equation (6) Is used as a representative point of the Nn _n block instead of Pl _{n in} the equation (5). Then, the linear axis movement amount L _n (n = 1, 2,..., Only by rotating from the (a _n−1 , c _n−1 ) of the A and C axis positions to (a _n , c _n ). ne) is obtained from Equation (6). Since L _n is the absolute value of the vector, it is a scalar quantity.

  This corresponds to the linear axis movement amount generated in each block by the rotation axis movement schematically described in the equation (1). The first parenthesis corresponds to “the amount of movement of the rotary shaft” in Equation 1, and the second parenthesis corresponds to “the distance between the position of the tool tip point and the table turning center”.

Next, calculation of the recommended machining center position Pa by method 1) (weighted average) and method 2) (least square method) will be described.
Method 1) (weighted average)
Linear axis motion amount Ln (n = 1,2, ···, ne) such that the sum of decreases, the midpoint of Nn _n-1 the end of the block and Nn _n end of the block as a representative point of Nn _n blocks, the number The recommended machining center position Pa (Pax, Pay, Paz) ^T is obtained by performing a weighted average when L _n is considered as a weight for the same as in Equation 7. Obtaining the recommended machining center position Pa so that the total of the linear axis movement amounts Ln (n = 1, 2,..., Ne) becomes smaller is to shift the machining point so that Pa becomes the table turning center. it is conceivable that.

This is illustrated between the vector Pl _n-1 and the vector Pl _n as shown in FIG. The midpoint between the vector Pl _n-1 and the vector Pl _n here, Nn _n was a point representing the block, Nn _n Shuten Pl _n and Nn _n starting Pl _n-1 to Nn _n blocks of the block of the block It is good also as a point representing. Moreover, it can process sequentially, reading the command position of a linear axis and a rotating shaft. That is, it is not necessary to process the entire command program, that is, the entire machining program after reading it. Furthermore, in Equation 7, other machine configurations such as jigs, tables, spindles, tools, column columns, etc., and other machining conditions such as machining speed, spindle rotation speed, and tool type are taken into account. It is also possible.

Next, method 2) (least square method) will be described.
Method 2) (least square method)
In the second parenthesis in Equation 6, r _n = (r _xn , r _yn , r _zn ) ^T as in Equation 8.

  Let M be a matrix (matrix) of the matrix calculation of equation (9).

  Each element of the matrix M is expressed as follows.

Then, Equation 3, Equation 4, each element m _11n ~m _33n from equation (9) can be expressed by equation (11).

Assuming that the linear axis movement amount corresponding to Ln when the machining position of the workpiece is shifted by Pa is La _n (n = 1, 2,..., Ne), La _n is _expressed by Equation 12.

Then, as shown in Equation 13 Equation, the sum of squares of La _n and S, determined recommended processing center position Pa where S is minimized (Pax, Pay, Paz) and ^T the least squares method.

  From the least square method, conditional expressions of Formula 14 to Formula 16 can be applied.

  Equation (14) is derived from Equation (14).

  Equation (18) is derived from Equation (15).

  Equation (19) is derived from Equation (16).

Since the coefficients (α to σ) of Equation 17, Equation 18, and Equation 19 are values determined from the command positions and parameter setting values of the linear and rotary axes, Equation 17, Equation 18, Equation 19 The recommended machining center position Pa (Pax, Pay, Paz) ^T can be obtained by the simultaneous equations. Further, the coefficients (α to σ) of the equations (17), (18), and (19) can be sequentially processed while reading the command positions of the linear axis and the rotary axis, that is, the entire command program, that is, the entire machining program is read. point and need not be processed from here was a point representing the middle point Nn _n blocks between vectors Pl _n-1 and the vector Pl _n, the starting point of the end point Pl _n and Nn _n blocks of Nn _n block Method 1) (Weighting) Pl _n-1 may be used as a representative point of Nn _n blocks, and other components such as jig and table weight and machining conditions can be taken into account. Same as in the case of (average).

As a result, the recommended machining center position Pa is obtained for the command point sequences Pl _{0 to} Pl _ne as shown in FIG. 12 by the method 1) and the method 2). It is desirable to make Pa close to the turning center of the turning table. If possible, it suffices to make Pa coincide with the turning center of the turning table. Therefore, if there is no restriction on the linear axis machining possible area, which will be described later, Vrl (Vrlx, Vrly, Vrlz) ^{T in} Expression 20 is the recommended machining position change amount when expressed as the recommended table coordinate system origin shift amount.

If the recommended machining position change amount is expressed as the recommended table coordinate system origin position, Vr2 (Vr2x, Vr2y, Vr2z) ^{T in} Expression 21 is obtained.

  Further, since the same machining position change can be obtained by shifting the command linear axis position by Vrl and creating the machining program again, Vrl may be used as the recommended linear axis position shift amount as the recommended machining position change amount.

  However, in the case of the machining position as shown in FIG. 12, if the recommended table coordinate system origin position Vr2 is set as the table coordinate system origin, the machining is performed in the table itself. Of course, whether or not processing can be performed depends on the relationship between the processing position and the machine structure, and therefore processing may be possible without any particular problem using Vr2 as the origin of the table coordinate system. For example, in the case of a table turning 5-axis processing machine having a turning table generally called “trunion” as shown in FIG. 22, the table surface is below the table turning center (intersection position of the A axis rotation center and the C axis rotation center). Therefore, the recommended machining center position change amount can be obtained so that the recommended machining center position coincides with the table turning center or the recommended machining center position approaches the table turning center. In other words, processing may be possible with Vr2 as the origin of the table coordinate system.

In the case of FIG. 12, the linear axis command point sequences Pl _{0 to} Pl _ne must be within the processable area indicated by the broken line in FIG. That is, by changing the jig 4, it is possible to change the positions of Pl ₀ to Pl _ne so as to process within the broken line area, but change the positions of Pl ₀ to Pl _ne beyond that area. Cannot be ordered. Here, it is assumed that the linear axis machining region is set at the maximum position and the minimum position of each linear axis as follows.
AXmax: X-axis maximum position of the workable area AXmin: X-axis minimum position of the workable area AYmax: Y-axis maximum position of the workable area AYmin: Y-axis minimum position of the workable area AZmax: Z-axis maximum position of the workable area AZmin: Z-axis minimum position of the workable area Linear axis command point sequence Pl ₀ (x ₀ , y ₀ , z ₀ ) to Pl _n (x _n , y _n , z _n ) to Pl _ne (x _ne , y _ne , For z _ne ), the maximum command position and the minimum command position of each linear axis are calculated as shown in Equation 22.

Symbol Max (xn) is the maximum value of x _n (n = 0, 1, 2,..., Ne), and Min (x _n ) indicates the minimum value. The same applies to Y and Z. Therefore, CXmax and the like are as shown below.
CXmax: X-axis maximum position of command position CXmin: X-axis minimum position of command position CYmax: Y-axis maximum position of command position CYmin: Y-axis minimum position of command position CZmax: Z-axis maximum position of command position CZmin: Command position Z-axis minimum position FIG. 13 shows the Z axis minimum position by focusing on only these values on the table coordinate system. For simplicity, the Y and Z axes are shown, but the X axis is the same.

Here, as a recommended machining position change amount, Vr3 (Vr3x, Vr3y, Vr3z) is obtained as in Expressions 23 to 25. When focusing on Y-axis, and the Recommended processing position change amount Vr3y of Y-axis the amount closest to Vr1y within the scope that can (AYmin-CYmin) ~ (AYmax -CYmax) moving the linear axis command position Pl _yn To do.

The same applies to the X axis and the Z axis. The X axis corresponds to Formula 24, and the Z axis corresponds to Formula 25.

  As a result, the linear axis command point sequence is within the linear axis machining area, and the recommended machining center position Pa is as close to the table turning center as possible. Here, Vr3 is obtained as a shift amount, but is obtained from the equation 26 as the table coordinate system origin position Vr4.

  Generally, a command program (machining program) is created by CAM. In that case, Vrl or Vr2 is notified to the CAM as the recommended machining position change amount, and the command program is created again. At that time, the linear axis machining area including the linear axis is usually set in the CAM, and the linear axis machining area is set in the numerical control device, and equations 23, 24, and 25 are taken into consideration. It is not necessary to calculate the recommended machining position change amount for obtaining Vr3 as shown in FIG.

  In a table turning five-axis processing machine, there is often an interference between a tool and a machine part including a jig and a table due to a relationship with a rotary axis as well as a linear axis, and an interference check is often performed in a CAM. Therefore, in this case, Vr1 or Vr2 is input to the CAM as a recommended machining position change amount, and the program is recreated by the CAM while checking the interference condition including the linear axis machining possible region.

  Next, the block diagram of FIG. 15 will be described. In general, the numerical control apparatus reads a command program which is a machining program by the program reading means 10, analyzes the command program by the program analysis means 11, creates interpolation data, and performs interpolation at every interpolation cycle by the interpolation means 12. Then, the interpolation position of the control point is obtained, and the servo of each axis is driven so that the machine operates at the interpolation position of the control point. The recommended machining center position calculation means 14 and the recommended machining position change amount calculation means 15 are called from the program analysis means 11 to perform processing.

Next, the processing algorithm by the least square method will be described with reference to the flowchart shown in FIG. Hereinafter, it demonstrates according to each step.
[Step S100] In the G43.4 block, the commands Pl ₀ (x ₀ , y ₀ , z ₀ ), a ₀ , c ₀ are read, and the block commands Pl _n (x _n , y _n , z _n ), a _n , stored as c _n. The coefficients α to σ = 0. Let CXmax = CXmin = x ₀ , CYmax = CYmin = y ₀ , and CZmax = CZmin = z ₀ .
[Step S101] The next block is read.
[Step S102] It is determined whether or not the read block is a G49 block. If it is a G49 block, the process proceeds to Step S106. If it is not a G49 block, the process proceeds to Step S103.
[Step S103] The current block command Pl _n (x _n , y _n , z _n ), a _n , c _n is used as data Pl _n-1 (x _n−1 , y _n−1 , z _n ) one block before. _-1 ), a _n-1 , c _n-1 . This Nn _n block command _{Pl n (x n, y n} , z n), a n, and stores the c _n.
If ● [Step S104] x _n> CXmax, and CXmax = x _n. If x _n <CXmin, and CXmin = x _n. If y _n> CYmax, and CYmax = y _n. If y _n <CYmin, and CYmin = y _n. If z _n > CZmax, CZmax = z _n . If z _n <CZmin, CZmin = z _n is set.
● calculation of r _n by [Step S105] The number 8 expression, the calculation of M _n by number 9 expression. Calculate () portion in each Σ () of α, β, γ, δ of Equation 17 and ε, ζ, η, θ of Equation 18 and λ, μ, ξ, σ of Equation 19; Add to α to σ.
[Step S106] The recommended machining center position Pa is obtained by solving the simultaneous equations of Equations 17, 18, and 19.
[Step S107] It is determined whether or not the linear axis workable region is set. If it is set, the process proceeds to step S108, and if not set, the process proceeds to step S109.
[Step S108] Vr3 is calculated from Equation 23 to Equation 25, or Vr4 is calculated from Equation 26 to obtain a recommended machining position change amount, and the process is terminated.
[Step S109] Vr1 is calculated according to Equation 20 or Vr2 is calculated according to Equation 21 as a recommended machining position change amount, and the process is terminated.

(1-1-2) Calculation of linear axis movement amount in interpolation cycle Next, a case where the linear axis movement amount is calculated in interpolation cycle will be described.
First, the block diagram of FIG. 17 will be described. In the numerical control apparatus of this block diagram, the recommended machining center position calculation means 14 and the recommended machining position change amount calculation means 15 are called from the interpolation means 12 to perform processing. In this configuration, the n interpolation cycle interpolated linear axis interpolation position in (control point position) Pm _n, A axis position is a _n, is C-axis position if c _n, on the corresponding table coordinate system The tool tip point position Pl _n can be obtained from Equation 27.

Here, RA _n ^-1 is an inverse matrix with respect to the rotation matrix for a _n represented by Equation 3. RC _n ⁻¹ is an inverse matrix with respect to the rotation matrix for c _n expressed by Equation 4. Thus, by considering that the interpolation is performed from the first interpolation period to the neth interpolation period, the recommended machining center position is calculated by the same method as described in (1-1-1) above. The recommended machining position change amount can be calculated. That is, Equation 3, and Equation 4 for a _n, c _n is the rotational axis interpolated position of the n-th interpolation cycle (A, C axes interpolated position), straight line Pm _n of equation (5) of the n-th interpolation cycle As the axis control position, Pl _n and Pl _n-1 in Expression 7 are used as the linear axis command position in the table coordinate system in the n−1th and nth interpolation periods obtained by Expression 27, and from the first interpolation period The recommended machining center position Pa may be obtained using the same method as described above in (1-1-1) assuming that the interpolation is performed up to the neth interpolation cycle.

(1-2) When the command program coordinate system is a work coordinate system Next, a case where the command program coordinate system is commanded as a work coordinate will be described. In (1-1), the command in the table coordinate system has been described. However, even when commanded in the work coordinate system, the same calculation can be performed by converting the linear axis command position into the table coordinate system. In this case, the workpiece coordinate system is a coordinate system shifted by V _O from the machine coordinate system and does not move even if the table turns (see FIG. 18). By calculation of Eq. 28, the linear axis command position Pw _n on the workpiece coordinate system is converted into the position Pl _n on the table coordinate system assuming the origin to the table pivot Pc.

By regarding that Pl _n is commanded on the table coordinate system assuming that the table turning center Pc is the origin, the recommended machining center position Pa and the recommended machining position change amount are described in the same manner as described in (1-1). Can be requested.
(1-3) Processing and Simulation While Performing Processing The above-described methods (1-1) and (1-2) operate while actually performing processing, that is, for each axis in FIGS. 15 and 17. It is possible to operate while driving the servo, and it is also possible to operate by simulation. When operating by simulation, the numerical control device shown in FIG. 15 may be executed up to the program analysis means 11, and the numerical control device shown in FIG. 17 may be executed up to the interpolation means 12. Accordingly, the recommended machining center position Pa can be calculated and the recommended machining position change amount can be obtained without actually machining the workpiece.

  For example, the numerical control device already has a function of drawing only a machining path without actually performing machining as a graphic function. If the present invention is applied to this function, the recommended machining center position Pa and the recommended machining position change amount can be easily calculated by simulation.

(1-4) Mixed-type 5-axis processing machine The above-described (1-1) to (1-3) have been described as a 5-axis processing machine that turns a table with two rotation axes. Of these, the present invention is also applied to a 5-axis machine (refer to FIG. 19) called a mixed 5-axis machine, in which one axis is a rotary axis for turning the table and the other axis is a rotary axis for tilting the tool head. can do.
In the case of the mixed type 5-axis processing machine shown in FIG. 19, a straight line similar to that described with reference to FIGS. 2 to 5 depends on where the work 3 is placed on the table 1 rotated by the C axis. This is because the axial movement amount is different.

  For example, as shown in FIG. 20, when the mixed type 5-axis machine shown in FIG. 19 is viewed from the Z direction, when the workpiece 3 is placed near the table turning center and turned as shown in FIG. Thus, the tool tip point moves. On the other hand, when the workpiece 3 is placed away from the table turning center, the tool tip point moves as indicated by a broken line arrow shown in FIG. That is, even when the same workpiece 3 is machined with the same machining program, the movement distance of the tool tip point varies greatly depending on the position of the workpiece 3 (here, the origin position of the table coordinate system). In this case, since the linear axis movement amount is smaller in the machining state of FIG. 20, the machining time can be shortened and the energy required for the machining can also be reduced.

  Therefore, the present invention can also be applied to the mixed type 5-axis machine shown in FIG. However, in this case, since the rotation axis for table turning is only the C axis, the other rotation axes described in (1-1) to (1-3) (A in (1-1) to (1-3) There is no need to consider the axis (B-axis in the case of FIG. 19).

1 Table 1A A-axis table 1C C-axis table 2 Tool 3 Work 4 Jig 5,6 Dotted arrow indicating moving path of tool tip point Pa Recommended machining center position

Claims (12)

Table turning 5 that commands a tool direction and a linear axis position on a designated program coordinate system, and performs machining with a rotary axis 2 axis including 3 linear axes and at least one rotary axis for table rotation with respect to a workpiece attached to the table. A numerical control device for a table turning 5-axis machine that controls an axis machine,
A recommended machining center position calculating means for obtaining a recommended machining center position which is a position on the designated program coordinate system and which is a position where the movement amount of the linear axis is reduced as much as possible when moving to the table turning center of the table;
A recommended machining position change amount calculating means for obtaining a recommended machining position change amount so that the recommended machining center position matches the table turning center, or the recommended machining center position approaches the table turning center;
A numerical control device for a table turning 5-axis machine, comprising: The designated program coordinate system is a table coordinate system defined on a table,
The recommended machining position change amount is a recommended table coordinate system origin position, a recommended table coordinate system origin shift amount, or a recommended linear axis position shift amount with respect to a command linear axis position in a command program. Numerical control device for table turning 5 axis processing machine of statement.   The designated program coordinate system is a workpiece coordinate system shifted from a machine coordinate system, and the recommended machining position change amount is a recommended workpiece coordinate system origin position, a recommended workpiece coordinate system origin shift amount, or a command linear axis position in a command program. The numerical control device for a table turning five-axis processing machine according to claim 1, wherein the numerical value is a recommended linear axis position shift amount with respect to.   The said recommended processing center position calculation means calculates | requires by performing the calculation by a weighted average using the said linear axis command position and rotation axis command position in a command program, It is any one of Claims 1-3 characterized by the above-mentioned. Numerical control device for table turning 5-axis machine.   The recommended machining center position calculation means is obtained by performing calculation by a least square method using the linear axis command position and the rotation axis command position in a command program. Numerical control device for table turning 5 axis processing machine of statement.   The said recommended processing center position calculation means calculates | requires by performing the calculation by a weighted average using the linear-axis interpolation position and rotation axis interpolation position for every interpolation period, The determination of any one of Claims 1-3 characterized by the above-mentioned. Numerical control device for table turning 5-axis machine.   4. The recommended machining center position calculation means is obtained by performing calculation by a least square method using a linear axis interpolation position and a rotation axis interpolation position for each interpolation cycle. Numerical control device for table turning 5 axis processing machine of statement. Before Symbol recommended processing position change amount calculating means, to the extent that linear axis commanded sequence of points in the command program is a linear axis machining area that is set at the maximum position and the minimum position of workable linear axis, the recommended working The recommended machining position change amount is calculated so that a center position coincides with the table turning center or the recommended machining center position approaches the table turning center. Numerical control device for table turning 5 axis processing machine.   9. The numerical value for a table turning 5-axis machining apparatus according to claim 1, wherein the recommended machining center position calculating means operates while machining a workpiece by the table turning 5-axis machining apparatus. Control device.   The table turning 5-axis processing machine according to any one of claims 1 to 8, wherein the recommended processing center position calculating means operates by simulation without processing a workpiece by the table turning 5-axis processing machine. Numerical controller.   11. The two rotation axes of the table turning five-axis processing machine are characterized in that one of them is a rotation axis for turning the table and the other one is a rotation axis for tilting the table. The numerical control apparatus for table turning 5 axis | shafts processing machines as described in any one of these.   2. The rotary shafts of the table turning five-axis machine are characterized in that one of the two rotary shafts is a rotary shaft for turning the table and the other one is a rotary shaft for tilting the tool head. The numerical control device for a table turning five-axis processing machine according to any one of 10.

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