JP5413085B2 - Numerical control device for machine tool, control method for machine tool, control program for machine tool - Google Patents

Description

  The present invention relates to a numerical control device for a machine tool that controls positioning of a tool or a workpiece, a method for controlling a machine tool, and a control program for a machine tool.

  An NC machine tool (Numerical Control) used in recent years is automatically controlled by a numerical control device configured by a computer in accordance with an NC program. In this NC program, a plurality of commands for performing operation control and processing of each unit are described in a predetermined description order, and the numerical control device is a numerical value of the driving mechanism of each unit corresponding to each operation command in accordance with the description order. Take control.

  The movement of the moving part by one operation command is as follows: Accelerate in the initial speed increase section, then move at a constant speed at a constant speed in the constant speed section, and decelerate in the final deceleration section This is a series of steps to stop at the coordinate position. In both the acceleration and deceleration sections in any moving operation, acceleration / deceleration is performed with a predetermined acceleration that is fixedly set in consideration of the inertia due to the weight of the moving part and the braking capability of the drive mechanism. Done. Further, constant speed movement is performed at the same common movement speed in the constant speed section in any movement operation.

  Here, depending on the mode of movement, for convenience of the NC program, there may be a case where the operation command is divided into two parts with one position as a boundary. In this case, it is described separately as one movement command for reaching the one position and ending the movement, and another movement command for starting movement from the position and starting. In this way, when the command for movement is described by dividing it into two continuous movement commands, the traveling time is wasted by the amount of deceleration stop and acceleration start before and after the one position. .

  As a technique for eliminating this waste of travel time, a numerical control device that has received two consecutive movement commands connects two movements so as to connect the deceleration section of the preceding movement command and the acceleration section of the subsequent movement command. There is a method of synthesizing commands (see, for example, Patent Document 1).

  This numerical control device according to the prior art makes the start timing of the deceleration section of the preceding movement command coincide with the start timing of the acceleration section of the subsequent movement command. As a result, the deceleration section of the preceding movement command and the acceleration section of the subsequent movement command overlap, and the acceleration in the deceleration direction and the acceleration in the acceleration direction are canceled by this overlap. Constant speed movement is maintained. By performing such synthesis, even when the numerical controller receives two continuous movement commands, the movement control is performed only by a series of strokes in which each of the acceleration section, the constant speed section, and the deceleration section is performed once. It can be performed.

JP-A-1-276309

  As described above, the acceleration in the acceleration zone and the deceleration zone is usually fixed at a predetermined magnitude. For this reason, when the moving distance of the movement command is short, the deceleration section must be started in the middle of the speed increasing section that does not reach the predetermined moving speed in the constant speed section after the start of speed increasing.

  As a result, when the movement command is synthesized by the conventional technique when the movement distance of the subsequent movement command is significantly shorter than the movement distance of the preceding movement command, the following problems occur. That is, when the acceleration section of the subsequent movement command is started from the start timing of the deceleration section of the preceding movement command, the subsequent acceleration section ends and the deceleration section starts in the middle of the preceding deceleration section. For this reason, a section in which the deceleration sections of the preceding and subsequent movement commands overlap each other occurs. In the section where the deceleration sections overlap, the deceleration operation is performed with an acceleration twice as large as the normal speed. As a result, there is a risk that an excessive load is applied to the drive mechanism of the machine tool including, for example, a servo motor, and it is difficult to maintain the soundness of the machine tool.

  An object of the present invention is to provide a numerical control device, a machine tool control method, and a machine tool control program that can synthesize two continuous movement commands without imposing an excessive load on the drive mechanism and prevent waste of movement time. It is to provide.

In order to achieve the above object, the first invention is a numerical control for positioning and controlling a tool or a workpiece at a position designated by a positioning command including a moving direction and a moving amount based on a predetermined acceleration and speed. In the apparatus, a first speed calculation means for calculating an execution speed per unit time of the positioning command, and whether or not the execution speed of the current positioning command calculated by the first speed calculation means is a speed immediately before the start of deceleration. If the execution start speed is determined to be a speed immediately before the start of deceleration by the deceleration start determination means to be determined and the deceleration start determination means, a fetching means for fetching the next command and a next command fetched by the fetching means are a positioning command, and said determining means for determining whether a positioning command for the current positioning command in the same direction, the determining means Therefore if the current positioning command and the next positioning command is determined that the positioning command for the same direction, whether it can reach speeds the next positioning command is the predetermined said next positioning command Based on the amount of movement and the predetermined acceleration, and when the speed determining unit determines that the next positioning command cannot reach the predetermined speed, Based on the acceleration and the amount of movement of the next positioning command, changing means for changing the predetermined speed, and execution of the next positioning command per unit time based on the speed changed by the changing means A second speed calculating means for calculating a speed, an execution speed calculated by the first speed calculating means and a second speed calculating means. And a speed synthesizing means for synthesizing the line speed, said speed synthesis means, synthesis by execution speed that is calculated by the second speed calculating means at the start of deceleration by execution speed computed by the first speed calculating means The speed is increased until the predetermined constant speed for synthesis is reached, and then the constant speed is continuously moved at the constant speed for synthesis, and the deceleration by the execution speed calculated by the first speed calculating means is performed. decelerating the start of the synthesis reduction upon completion and said Rukoto.

The numerical control device for a machine tool according to the first invention of the present application performs positioning control of a tool or a workpiece of the machine tool. The first speed calculation means calculates an execution speed per unit time of the positioning command including the movement direction and the movement amount. A deceleration start determination means determines whether or not the current execution speed of the positioning command is a speed immediately before the start of deceleration. When the deceleration start determining means determines that the execution speed is the speed immediately before the start of deceleration, the capturing means captures the next positioning command . In the first invention of the present application, when two positioning commands are fetched before and after, the two positioning commands can be combined so that a useless stop operation is not performed. Determining means, next instruction fetched is a positioning command, and whether or not the positioning command for the current positioning command in the same direction, it is determined. If the judgment is satisfied, it is considered that synthesis is possible.

  When the amount of movement of the next positioning command is considerably smaller than the amount of movement of the current positioning command, the acceleration in the deceleration section becomes excessively large during positioning by a command obtained by combining these two commands.

  In the first invention of this application, the speed determining means determines whether or not the next positioning command can reach the predetermined speed based on the movement amount of the next positioning command and the predetermined acceleration. .

  If it is determined that the predetermined speed cannot be reached, it is assumed that there is a possibility that the acceleration in the deceleration section by the synthesized command may become excessively large as it is, and the changing means changes the predetermined speed described above. Do. The second speed calculation means calculates the execution speed per unit time of the next positioning command based on the changed speed, and the speed synthesis means calculates the execution speed calculated by the second speed calculation means and the first speed calculation means. Is combined with the execution speed calculated by. Thus, as described above, it is possible to prevent the travel time from being wasted by combining the two commands while preventing the acceleration in the deceleration section from becoming excessively large and imposing an excessive burden on the drive mechanism. As a result, the soundness of the machine tool can be maintained and the machine tool can be operated safely.

  In a second aspect based on the first aspect, when the speed determining means determines that the next positioning command can reach the predetermined speed, the second speed calculating means Based on the above, the execution speed per unit time of the next positioning command is calculated.

  As a result, when the movement amount of the next positioning command is not equal to or less than the movement amount of the current positioning command, the conventional positioning command can reach a predetermined positioning speed by combining the two commands. Positioning control can be performed.

  According to a third aspect of the present invention, in the first or second aspect, the machine tool includes a column, a spindle head that is movably supported by the column, and a tool that is rotatably supported by the spindle head and mounted at the lower end. And a tool changer provided in the column, wherein the current positioning command is a position where the spindle head is attached to a tool attached to the spindle to the tool changer, or the tool. A command for positioning a tool mounted on a changer device to a tool replacement preparation position that is a position for mounting on the spindle, and the next positioning command fetched by the taking-in means is that the spindle head is moved from the tool replacement preparation position. It is a command for positioning to a position above or below the tool change preparation position.

  In general, a machine tool performs predetermined processing on a workpiece by holding and rotating a tool on a spindle supported by a spindle head. The spindle can be used by attaching and detaching a plurality of tools by using a tool changer. In the numerical control device for a machine tool according to the third aspect of the present invention, after the command for positioning the spindle head to the tool change preparation position, the take-in means positions the tool head from the tool change preparation position to a position above or below the tool change preparation position. Capture the command to be performed.

  Thereby, the adverse effect due to the large acceleration can be prevented at the time of the above tool change when moving upward with the tool change preparation position sandwiched or when moving downward with the machining reference position sandwiched. That is, the acceleration in the deceleration zone can be prevented from becoming excessively large by combining the current positioning command to the tool change preparation position and the next positioning command from the tool change preparation position.

In order to achieve the above object, a fourth invention is a machine tool for positioning and controlling a tool or a workpiece at a position instructed by a positioning command including a moving direction and a moving amount based on a predetermined acceleration and speed. A first speed calculation procedure for calculating an execution speed per unit time of the positioning command, and a speed at which the current positioning command calculated in the first speed calculation procedure is a speed immediately before the start of deceleration. When the deceleration start determination procedure for determining whether or not the execution speed is the speed immediately before the deceleration start is determined by the deceleration start determination procedure, the acquisition procedure for acquiring the next command and the acquisition procedure the following command is a positioning command, and the a judgment procedure for judging whether the positioning command for the current positioning command in the same direction, the current in the determination procedure If the command and the next positioning command Me-decided is determined to be positioning command for the same direction, whether said next positioning command can reach the speed of the predetermined movement of the next positioning command A speed determination procedure to be determined based on an amount and the predetermined acceleration; and if the next positioning command is determined to be unable to reach the predetermined speed in the speed determination procedure, the acceleration And a change procedure for changing the predetermined speed based on the movement amount of the next positioning command, and an execution speed per unit time of the next positioning command based on the speed changed in the change procedure a second speed calculation procedure for calculating a, a, a speed synthesis procedure for synthesizing the computed execution speed computed and execution speed by the second speed calculation procedure in the first speed algorithm For example, in the speed synthesis procedure, the first speed calculation procedure predetermined constant velocity speed for synthesis initiates synthesis for acceleration by the execution rate calculated in the second speed calculation procedure at the start of deceleration by execution speed calculated in The speed is continuously increased at a constant speed for synthesis, and when the deceleration at the execution speed calculated by the first speed calculation procedure is completed, the deceleration for synthesis is started and decelerated. It is characterized by that.

The machine tool control method of the fourth invention of the present application performs positioning control of the tool or workpiece of the machine tool. In the first speed calculation procedure, the execution speed per unit time of the positioning command including the moving direction and the moving amount is calculated. In the deceleration start determination procedure, it is determined whether or not the execution speed of the current positioning command is the speed immediately before the start of deceleration. When it is determined in the deceleration start determination procedure that the execution speed is the speed immediately before the deceleration start, the next positioning command is captured in the capture procedure. In the fourth invention of the present application, when two positioning commands are taken in before and after, the two positioning commands can be combined to prevent a useless stop operation. In the determination procedure, it is determined whether or not the next command fetched is a positioning command and positioning in the same direction as the current positioning command. If the judgment is satisfied, it is considered that synthesis is possible.

  When the amount of movement of the next positioning command is considerably smaller than the amount of movement of the current positioning command, the acceleration in the deceleration section becomes excessively large during positioning by a command obtained by combining these two commands.

  In the fourth invention of the present application, in the speed determination procedure, it is determined whether or not the next positioning command can reach the predetermined speed based on the movement amount of the next positioning command and the predetermined acceleration. .

  If it is determined that the predetermined speed cannot be reached, it is assumed that the acceleration of the deceleration section by the synthesized command may be excessively increased as it is, and the above predetermined speed change is performed in the change procedure. Do. In the second speed calculation procedure, the execution speed per unit time of the next positioning command is calculated based on the changed speed, and the execution speed calculated in the second speed calculation procedure and the first speed calculation procedure are calculated in the speed synthesis procedure. Is combined with the execution speed calculated in. Thus, as described above, it is possible to prevent the travel time from being wasted by combining the two commands while preventing the acceleration in the deceleration section from becoming excessively large and imposing an excessive burden on the drive mechanism. As a result, the soundness of the machine tool can be maintained and the machine tool can be operated safely.

In order to achieve the above object, the fifth invention provides a positioning command for instructing a computer a position for positioning control of a tool or a workpiece based on a predetermined acceleration and speed, including a moving direction and a moving amount. The first speed calculation procedure for calculating the execution speed per unit time, and the deceleration start determination for determining whether the execution speed of the current positioning command calculated in the first speed calculation procedure is the speed immediately before the start of deceleration. If it is determined in the procedure and the deceleration start determination procedure that the execution speed is the speed immediately before the deceleration start, the capture procedure for capturing the next command and the next command captured in the capture procedure are positioning commands. and wherein a determination procedure for determining whether a positioning command for the current positioning command in the same direction, the current positioning command and subsequent positioning in the determination procedure If the the decree is determined to be positioning command for the same direction, whether said next positioning command can reach the speed of the predetermined amount of movement of the said next positioning command, the predetermined If it is determined that the next positioning command cannot reach the predetermined speed in the speed determining procedure to be determined based on the determined acceleration and the speed determining procedure, the acceleration and the next positioning command A change procedure for changing the predetermined speed based on the movement amount, and a second speed calculation for calculating an execution speed per unit time of the next positioning command based on the speed changed in the change procedure and procedures, and executes and a speed synthesis procedure for synthesizing the computed execution speed in said the computed execution speed at a first speed algorithm second speed calculation procedure, the rate In the composition procedure, at the start of deceleration by the execution speed calculated in the first speed calculation procedure, the composition acceleration is started by the execution speed calculated in the second speed calculation procedure and increased until a predetermined constant constant speed is reached. After the speed is increased, the speed is continuously moved at the constant speed for synthesis. When the deceleration at the execution speed calculated by the first speed calculation procedure is completed, the deceleration for synthesis is started and the deceleration is executed .

  A computer equipped with a machine tool control program of the fifth invention of the present application performs positioning control of a tool or a workpiece of a machine tool.

The computer executes the first speed calculation procedure, and calculates the execution speed per unit time of the positioning command including the movement direction and the movement amount. The computer executes a deceleration start determination procedure, and determines whether or not the current positioning command execution speed is just before the deceleration start. When it is determined in the deceleration start determination procedure that the execution speed is the speed immediately before the start of deceleration, the computer executes the capture procedure and captures the next positioning command . In the fifth invention of the present application, when two positioning commands are fetched before and after, the two positioning commands can be combined so that a useless stop operation is not performed. Computer executes the determination procedure, the next instruction fetched is a positioning command, and, whether the positioning command for the current positioning command in the same direction, it is determined. If the judgment is satisfied, it is considered that synthesis is possible.

  When the amount of movement of the next positioning command is considerably smaller than the amount of movement of the current positioning command, the acceleration in the deceleration section becomes excessively large during positioning by a command obtained by combining these two commands.

  In the fifth invention of the present application, whether or not the next positioning command can reach the predetermined speed based on the movement amount of the next positioning command and the predetermined acceleration is executed by the computer. Judge.

  If it is determined that the predetermined speed cannot be reached, it is assumed that there is a possibility that the acceleration of the deceleration section by the synthesized command may be excessively increased as it is, and the computer executes the change procedure, and the above predetermined Change the speed. The computer executes the second speed calculation procedure, calculates the execution speed per unit time of the next positioning command based on the changed speed, the computer executes the speed synthesis procedure, and calculates in the second speed calculation procedure The execution speed and the execution speed calculated in the first speed calculation procedure are synthesized. Thus, as described above, it is possible to prevent the travel time from being wasted by combining the two commands while preventing the acceleration in the deceleration section from becoming excessively large and imposing an excessive burden on the drive mechanism. As a result, the soundness of the machine tool can be maintained and the machine tool can be operated safely.

  According to the present invention, it is possible to synthesize two continuous movement commands without imposing an excessive burden on the drive mechanism, and to prevent waste of movement time.

It is a side view showing the whole machine tool composition provided with the numerical control device concerning the embodiment of the present invention. It is a longitudinal cross-sectional view showing a Z-axis movement apparatus and its surrounding structure in detail. It is a longitudinal cross-sectional view which expands and shows the periphery of the main axis | shaft and tool magazine at the time of tool replacement | exchange. It is a functional block diagram showing typically an electric system configuration of a machine tool. It is a block diagram which shows the software structural example of the control program which operate | moves in a numerical control apparatus. It is a figure explaining the calculation method of the input voltage which a previous input voltage calculation part and this time input voltage calculation part perform. FIG. 7A is a diagram showing a description example of the NC program, and FIG. 7B is a diagram conceptually showing the geometric arrangement of each stop point. FIG. 8A is a time chart of the travel stroke when not synthesizing corresponding to the example shown in FIG. 7, and FIG. 8B is a time chart of the travel stroke when synthesized. FIG. 9A is a diagram showing a description example of the NC program when the movement distance of the second movement command is short, and FIG. 9B conceptually shows the geometric arrangement of each stop point. FIG. FIG. 10A is a time chart of the movement process when not synthesized corresponding to the example shown in FIG. 9, and FIG. 10B is a time chart of the movement process when synthesized. FIG. 10 is a time chart of a travel stroke when combined so as not to cause excessive deceleration corresponding to the example shown in FIG. 9. It is a flowchart showing the control procedure performed by CPU of a numerical controller. It is a flowchart showing the detailed procedure of the movement control process performed in step S100 in FIG. It is a figure which shows the case where this invention is applied to two continuous movement commands moved simultaneously with respect to the same plurality of axial directions.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing the overall configuration of the machine tool of the present embodiment. In FIG. 1, a machine tool 1 includes an XY axis moving device (not shown), a Z axis moving device 5, a spindle driving device 20, a tool changer 2, and the like.

  An XY axis moving device (not shown) moves the table 135 holding the workpiece in the X and Y directions perpendicular to each other. The table 135 is moved by an X-axis motor 131 (see FIG. 4 described later) and a Y-axis motor 132 (see FIG. 4 described later). The Z-axis moving device 5 moves the spindle 22 and the spindle head 6 up and down. The main shaft driving device 20 rotationally drives the main shaft 22. The tool changer 2 automatically transfers the tool holder 75 (see FIG. 2 described later) to the spindle 22. The machine tool 1 is integrally provided with a numerical control device 9 that numerically controls the operations of the plurality of moving mechanisms and drive mechanisms.

  The tool changer 2 includes a vertical column 3, a frame 4, a spindle head 6, a tool magazine 8, and the like. The frame 4 extends forward from the column 3 and supports the tool magazine 8. The spindle head 6 reciprocates in the Z-axis direction by driving a Z-axis motor 15 provided in the Z-axis moving device 5. The tool magazine 8 is rotatably supported on the frame 4 via the magazine support 7.

  The machine tool 1 is provided with a storage tank 134 for storing a coolant liquid on the back side. The machine tool 1 has a storage tank 86 inside. The storage tank 86 stores the coolant liquid sucked by the pump 83 (see FIG. 4 described later) from the storage tank 134 as a cleaning liquid.

  FIG. 2 is a longitudinal sectional view showing in detail the configuration of the Z-axis moving device 5 and its surroundings. In FIG. 2, the column 3 includes a guide rail 11 in the vertical direction. The guide rail 11 is attached with a spindle head 6 through a pair of sliding pieces 12 so as to be movable up and down in the vertical Z-axis direction. The column 3 is provided with a rotatable ball screw 14 in parallel along the guide rail 11. The ball screw 14 is inserted while being screwed into a nut 13 fixed to the back surface of the spindle head 6. The ball screw 14 rotates in both forward and reverse directions by driving a Z-axis motor 15 disposed on the top of the column 3. The spindle head 6 moves in the vertical direction along the guide rail 11 via the ball screw 14 and the nut 13 by driving the Z-axis motor 15.

  The spindle head 6 includes a spindle 22 in the vertical direction so as to be rotatable. The main shaft 22 is connected to a main shaft motor 23 disposed above the main shaft head 6 via a coupling 24. The main shaft 22 is rotationally driven by a main shaft motor 23. The main shaft 22 has a tool mounting portion 21 at its lower end.

  In the example shown in the figure, the tool mounting portion 21 can be fitted with a taper engaging portion 75a in a tool holder 75 having a cutting tool 74 mounted on the tip. The main shaft 22 has a holder clamping portion 25 above the tool mounting portion 21. The main shaft 22 has a draw bar 26 above the holder clamping portion 25. The draw bar 26 includes a spring, and the holder holding portion 25 always acts to clamp the pull stud 75 b provided at the tip end of the tool holder 75 attached to the tool attachment portion 21. The holder clamping unit 25 releases the clamp of the pull stud 75b by pressing the draw bar 26, and the tool holder 75 can be removed.

  The spindle head 6 includes a crank lever 28 that presses or releases the draw bar 26. The support shaft 27 supports a substantially L-shaped crank lever 28 in a swingable manner. The crank lever 28 includes a short lever 28a integrally formed in the horizontal direction and a long lever 28b integrally formed in the vertical direction. The distal end portion of the short lever 28 a can be engaged with a pin 29 that projects orthogonally to the draw bar 26.

  The long lever 28b fixes a plate cam 30 having an inclined surface. The plate cam 30 can be engaged with and disengaged from a cam follower 31 disposed in the Z-axis motor 15. The tension coil spring 32 is interposed between the long lever 28b and the spindle head 6, and always urges the crank lever 28 in the clockwise direction in FIG. The tension coil spring 32 releases the pressing of the pin 29 by the short lever 28a.

  When the spindle head 6 is raised, the plate cam 30 provided on the crank lever 28 is engaged with the cam follower 31 located at the fixed position in the raising process. The engagement gives the crank lever 28 a counterclockwise movement in the drawing around the support shaft 27. Therefore, the short lever 28a presses the pin 29 downward, biases the holder holding portion 25 via the draw bar 26, and releases the clamp of the tool holder 75 from the pull stud 75b.

  When the spindle head 6 moves to the Z-axis origin position (see FIG. 3 described later) during tool replacement, the grip arm 38 located at the lowermost end of the tool magazine 8 holds the tool holder 75 to which the used cutting tool 74 is attached. To do. Thereafter, the crank lever 28 presses the draw bar 26 and clamps the tool holder 75 against the pull stud 75b while the spindle head 6 moves vertically up to the ATC origin position (see FIG. 3 described later) as the tool change position. Is released. Since the grip holder 38 holds the tool holder 75 attached to the spindle 22, the tool holder 75 is extracted from the tool attachment portion 21 of the spindle head 6. The Z-axis origin position is a position where the spindle head 6 is attached to the tool changer 2 with the cutting tool 7 attached to the spindle 22, and the position where the cutting tool 7 attached to the tool changer 2 is attached to the spindle 22. It is. Therefore, the Z-axis origin position corresponds to the tool change preparation position.

  Next, the magazine base 36 is rotated by the rotation drive of the magazine motor 46, and the grip arm 38 holding the tool holder 75 to which the cutting tool 74 used in the next cutting operation is attached is provided on the tool mounting portion 21 of the spindle head 6. Moves directly under and is positioned. This positioning movement of the grip arm 38 due to the rotation of the magazine base 36 is called an indexing operation. Thereafter, since the spindle head 6 moves downward in the vertical direction, the newly determined tool holder 75 is inserted into the tool mounting portion 21 of the spindle head 6 to complete the tool exchange. While the spindle head 6 is descending, the crank lever 28 interrupts the pressing of the draw bar 26 by the spring force of the tension coil spring 32. Therefore, the holder clamping unit 25 clamps the tool holder 75 inserted into the tool mounting unit 21.

  FIG. 3 is an enlarged longitudinal sectional view showing the periphery of the spindle 22 and the tool magazine 8 at the time of tool change. In the state shown in FIG. 3, the spindle head 6 has moved to the most elevated position by the rotational drive of the Z-axis motor 15 (see FIG. 2 described above). The tool holder 75 held by the grip arm 38 is located below the lower end surface of the spindle head 6. In this state, the lower end surface of the spindle head 6 is sufficiently separated from the pull stud 75 b at the upper end portion of the tool holder 75. Therefore, the tool magazine 8 can be freely indexed without the tool holder 75 interfering with the main shaft 22. The position of the lower end surface of the spindle head 6 in such a state is called the ATC origin.

  From the state shown in the drawing, the spindle 22 is lowered by driving the Z-axis motor 15, and the lower end surface of the spindle head 6 is made to coincide with the upper end surface of the bowl-shaped portion 75 c of the tool holder 75, whereby the tool holder 75 is moved to the spindle 22. Can be attached. At this time, as described above, the holder holding portion 25 clamps the pull stud 75 b of the tool holder 75 inside the main shaft 22. The position of the lower end surface of the spindle head 6 in such a state is referred to as the Z-axis origin.

  The spindle head 6 is provided with a plurality of cleaning nozzles 81 around its lower end surface and the opening portion of the tool mounting portion 21. The plurality of cleaning nozzles 81 spray the cleaning liquid supplied from the cleaning liquid circuit 82 slightly below the opening of the tool mounting portion 21, that is, toward the position of the taper engaging portion 75a in the state shown in the drawing.

  Next, the electrical configuration of the machine tool 1 will be described. As shown in FIG. 4, the numerical controller 9 described above has a control circuit 110 and various drive circuits 121 to 128. The control circuit 110 controls a machining operation and a tool change operation of the machine tool 1 by executing a control program or the like stored in the ROM 112 described later. The control circuit 110 basically includes a microcomputer including a CPU 111, a ROM 112, and a RAM 113, an input interface 114, and an output interface 115. The RAM 113 stores and holds an NC program for performing desired machining on the machine tool 1. The NC program includes a plurality of commands, and is created by an operator via an operation panel described later. The NC program will be described in detail later.

  The input interface 114 includes a keyboard 130 of an operation panel (not shown) provided on the front surface of the machine tool 1 and a liquid level sensor 136 provided in a storage tank 134 (see FIG. 1 described above) for storing the cleaning liquid in the cleaning liquid circuit 82. And are electrically connected. The output interface 115 includes a drive circuit 121 that drives the X-axis motor 131, a drive circuit 122 that drives the Y-axis motor 132, a drive circuit 123 that drives the Z-axis motor 15, and a drive circuit 124 that drives the spindle motor 23. A driving circuit 125 for driving the magazine motor 46, a driving circuit 126 for driving the pump 83 as a driving source for the cleaning liquid in the cleaning liquid circuit 82, a driving circuit 127 for driving the CRT 133 of the operation panel, The driving circuit 128 for driving the electromagnetic valve 97 for controlling the flow of the cleaning liquid in the cleaning liquid circuit 82 is electrically connected to each other. The X-axis motor 131 includes an encoder 131a that detects the position of the table 135 in the X-axis direction. The Y-axis motor 132 includes an encoder 132a that detects the position of the table 135 in the Y-axis direction. The Z-axis motor 15 includes an encoder 6a that detects the position of the spindle head 6 in the Z-axis direction. The encoders 131a, 132a, 6a are connected to the input interface 114. In the example of the present embodiment, the motors 15, 131, and 132 have specifications that rotate at a rotational speed proportional to the input voltage, for example.

  FIG. 5 is a block diagram showing a software configuration example of a control program that operates in the numerical controller 9 shown in FIG.

  The control program includes an NC program decoding unit 201, a movement command execution unit 202, a previous input voltage calculation unit 203, a current input voltage calculation unit 204, and a servo control unit 205 as its functions. To demonstrate.

  First, the NC program 301 (see FIGS. 7A and 9A described later) is a control procedure in which a plurality of commands for performing operation control and processing of each unit are described in a predetermined description order as described above. It is. The NC program 301 is previously input by the operator via the keyboard 130 and stored in the RAM 113.

  The NC program decoding unit 201 reads commands according to the description order of the NC program 301, and performs numerical control of the drive mechanism of each unit corresponding to the commands. Then, the NC program decoding unit 201 outputs a movement command as a positioning command related to the movement of each unit among the read commands to the movement command execution unit 202.

  The movement command execution unit 202 analyzes the contents of the movement command input from the NC program decoding unit 201 and executes the processing. In the present embodiment, two movement commands described in succession in the NC program 301 are combined and executed when a predetermined condition is satisfied. At this time, the movement command read in advance is output to the previous input voltage calculation unit 203 as the previous command as the current positioning command, and the current input voltage is calculated as the current command as the next positioning command. Output to the unit 204.

  The previous input voltage calculation unit 203, based on the previous command processing parameter (see FIG. 6 described later) set in response to the previous command input from the movement command execution unit 202, at that time, the motors 15 for the respective axes. , 131 and 132 are calculated. Similarly, the current input voltage calculation unit 204 is based on the current command processing parameter (see FIG. 6 described later) set in response to the current command input from the movement command execution unit 202, and at each point in time, The value of the input voltage to be input to the shaft motors 15, 131, 132 is calculated. The calculation methods of the previous input voltage calculation unit 203 and the current input voltage calculation unit 204 will be described in detail later with reference to FIG.

  The servo control unit 205 includes motors 15, 131, and 132 that specify the voltage corresponding to the sum of the input voltage values calculated by the previous input voltage calculation unit 203 and the current input voltage calculation unit 204, respectively, according to the movement command. To control the drive.

  With the above software configuration, the control program of the numerical controller 9 performs positioning movement control of each part in response to the movement command described in the NC program.

  Next, the calculation method of the input voltage performed by the previous input voltage calculation unit 203 and the current input voltage calculation unit 204 will be described with reference to FIG.

  FIG. 6A is a time chart showing the change over time in the value of the input voltage calculated by the previous input voltage calculation unit 203 or the current input voltage calculation unit 204 in response to one movement command. FIG. 6B shows the moving speed of the moving portion corresponding to the case where the servo control unit 205 directly inputs the input voltage shown in FIG. 6A to each of the shaft motors 15, 131, 132 and performs drive control. It is a time chart which shows a time-dependent change. 6A and 6B are applied in common to the previous input voltage calculation unit 203 and the current input voltage calculation unit 204 described above. In the following, for convenience of explanation, the description will be limited to only movement in the Z-axis direction. The “same direction” indicates that the positive direction or the negative direction along the Z axis is the same.

  First, as shown in FIG. 6 (b), the movement operation of the moving part by one movement command is basically the constant speed movement at a predetermined speed in the constant speed section after accelerating in the initial speed increasing section. To do. After that, it is a process of decelerating in the final deceleration zone and stopping the moving part at the target coordinate position.

  In any moving operation, in the acceleration and deceleration sections, acceleration / deceleration is performed at a fixed acceleration that takes into account the inertia of the moving part and the braking capacity of the drive mechanism. Like to do. That is, for any movement command, the acceleration in the acceleration zone is the same, and the deceleration in the deceleration zone is the same. And the absolute value becomes the same in any acceleration and deceleration.

  In the present embodiment, in the normal case, in any moving operation, the constant speed movement is performed at the “normal constant speed” of the same size in the constant speed section. However, in a special case to be described later, the constant speed section is moved at a constant speed with an appropriately adjusted “composite constant speed”. That is, the constant speed section speed F in the constant speed section is set to the normal constant speed or the synthesizing constant speed.

  In this embodiment, basically, when a movement command is input, the execution of the command is started immediately, and the stroke of the movement operation in the speed increasing section, the constant speed section, and the deceleration section is started. However, when a predetermined condition to be described later is not satisfied, a series of moving operation steps is started at an arbitrary timing.

  From the above, the stroke of the movement operation performed in response to the execution of one movement command is uniquely defined by the setting at the start of the movement command and the setting of the constant speed section speed in the constant speed section. The In the present embodiment, the movement command execution unit 202 appropriately sets the setting of the command start time and the constant velocity section speed as a command execution parameter in response to the one movement command.

  Then, the previous input voltage calculation unit 203 and the current input voltage calculation unit 204 are based on one movement command input from the movement command execution unit 202 and the corresponding command execution parameter, and each of the shaft motors 15, 131, The value of the input voltage to be input to 132 is sequentially calculated. That is, the previous input voltage calculation unit 203 and the current input voltage calculation unit 204 are illustrated in FIG. 6A so that the travel operation stroke defined by the command execution parameters as illustrated in FIG. 6B can be performed. The value of the input voltage corresponding to the time is calculated at such a short cycle. The speed at which the moving part moves according to each of the input voltage values sequentially calculated in this way corresponds to the execution speed per unit time described in each claim.

  As described above, since the acceleration in the acceleration section is the same for any one movement command, the speed change line in the acceleration section in the movement speed time chart as shown in FIG. The upward slope is constant. Similarly, the downward slope of the speed change line in the deceleration zone is also constant. In addition, the slope in the acceleration zone and the slope in the deceleration zone are symmetric with respect to the time direction. In addition, in the movement speed time chart as shown in FIG. 6B, the area S surrounded by the speed change line of the movement stroke corresponding to one movement command, as shown by the hatched portion in the figure, is the movement command. Is equivalent to the distance traveled by.

  Next, the NC program 301 is described as in the example shown in FIG. The command “N1 G0 Z100.0;” described in the first line in the figure is a command to move to a point P that is advanced by a distance of +100.0 in the Z-axis direction with respect to the current point. It is a movement command to do. This is referred to as a movement command N1. The command “N2 G0 Z200.0;” described in the second line instructs the positioning to further move to a point Q advanced by a distance of +200.0 in the Z-axis direction with respect to the current point. It is a movement command. This is referred to as a movement command N2. The current point is 0 on the Z axis.

Originally, the movement command N1 is not described, and the moving part can be positioned and moved from the current point to the point Q only by the movement command N2. However, when the point P is the tool change preparation position, that is, the Z-axis origin shown in FIG. 3, the NC program 301, for the sake of convenience, shows two continuous movement commands N1 and movement as shown in FIG. which may be positioned moved separately in a command N2. That is, as shown in FIG. 7B, the description is divided into a preceding movement command N1 until reaching the Z-axis origin P and ending the movement, and a subsequent movement command N2 starting from the movement and starting. Will be.

In this way, when the command for linear movement is described by dividing it into two continuous movement commands N1 and N2 , the Z-axis as shown in FIG. Before and after the origin P, the travel time is wasted as much as the deceleration stop and the acceleration start are performed.

Therefore, as one method of eliminating this waste of travel time, the travel command execution unit 202 that has received these two continuous travel commands N1 and N2 receives the deceleration section of the preceding travel command N1 and the subsequent travel command N2. The two continuous movement commands N1 and N2 are combined so as to connect the two speed increasing sections. Specifically, these two consecutive movement commands N1 and N2 are combined and connected so as to start a speed-up zone of the subsequent movement command N2 at the start timing of the deceleration section of the preceding movement command N1.

  As a result, as shown in FIG. 8B, the deceleration section of the preceding movement command N1 and the acceleration section of the subsequent movement command N2 coincide, and due to this overlap, deceleration in the deceleration direction and acceleration in the acceleration direction are performed. As a result, the constant speed movement at the normal constant speed F1 is maintained. As a result of combining and connecting the two movement commands N1 and N2, the movement control can be performed in one movement operation step in which each of the speed increasing section, the constant speed section, and the deceleration section is performed once. As a result, the entire movement time can be shortened by the time width of the deceleration section in the subsequent movement command N2.

  In this combined connection, the movement command execution unit 202 inputs the preceding movement command N1 to the previous input voltage calculation unit 203, and inputs the subsequent movement command N2 to the current input voltage calculation unit 204 at the start of the deceleration section of the movement stroke. This is possible by executing each of them.

  In addition, as described above, this combined connection performs acceleration / deceleration at an acceleration having the same absolute value, although the sign of each movement command N1, N2 is different in positive and negative signs. In the constant speed section, it is possible to move at the same normal constant speed F1. From these facts, it is assumed that the time widths of the deceleration zone and the acceleration zone are necessarily the same.

This combined connection can be performed on condition that two consecutive movement commands N1 and N2 are movement commands in the same direction. For this reason, when the movement directions of two consecutive movement commands N1 and N2 are different from each other, the subsequent movement command N2 is executed after completion of execution of the movement command N1 without performing the combined connection.

  Here, when the distance moved by one movement command is shorter than a predetermined length, a special situation occurs. For example, as shown in the NC program 301 of FIG. 9 corresponding to FIG. 7, when the movement by the subsequent movement command N2 moves a short distance of substantially +5, it corresponds to FIG. 8A. The travel process is as shown in FIG.

That is, as described above, since the absolute values of the respective accelerations in the acceleration zone and the deceleration zone are fixed equally, the normal constant speed F1 in the middle of the acceleration zone in the movement stroke corresponding to the subsequent movement command N2. The deceleration zone must be started before reaching. In this case, the speed is increased in the speed increasing section, and when the maximum speed F2 lower than the normal constant speed F1 is reached, the speed immediately decreases in the speed reducing section. Then, the time widths of the speed increasing section and the deceleration section are shorter than the time widths of the normal speed increasing section and the deceleration section.

When the subsequent movement command N2 for moving by a relatively short movement distance continues immediately after the preceding movement command N1 for reaching the positioning reference point with a sufficiently long movement distance in this way, the above-described synthetic connection is performed. If applied as it is, the following problems arise. That is, if the acceleration section of the subsequent movement command N2 is started at the start timing of the deceleration section of the preceding movement command N1, the acceleration section of the subsequent movement command N2 is completed in the middle of the deceleration section of the preceding movement command N1. Then, the deceleration zone is started. For this reason, a section in which the respective deceleration sections of the preceding movement command N1 and the subsequent movement command N2 overlap is generated. In this overlapping section, the deceleration operation is performed at twice the normal deceleration. Therefore, an excessive load exceeding the braking capacity of the corresponding drive mechanism such as the motors 15, 131, 132, etc. I will spend.

In the present embodiment, in order to solve this problem, to synthesize connections from a subsequent stroke of movement command N2 for moving only a relatively short distance traveled, as a deformed movement command N2 'as shown in FIG. 11 . That is, as the travel stroke of the modified travel command N2 ′, the composite acceleration zone is started at the start of the deceleration zone in the travel stroke of the preceding travel command N1 until the composite constant speed is adjusted appropriately. Increase the speed in the speed increasing section for synthesis. Then, as the travel stroke of the transformed movement command N2 ′, when the constant speed for synthesis is reached and then the constant speed movement is performed at the constant speed for synthesis, the deceleration section in the movement stroke of the preceding movement command N1 is completed. Next, a synthesizing deceleration zone is started, and the moving stroke is decelerated.

The movement stroke of the movement command N2 'thus deformed is started simultaneously with the deceleration section of the preceding movement command N1, and is combined and connected, so that each deceleration section of the preceding movement command N1 and the modified movement command N2' is obtained. Will be executed continuously without duplication. In this case, the deceleration in the deceleration section of the preceding movement command N1 and the acceleration in the composition acceleration section cancel each other out at the normal constant speed between the combined acceleration sections of the deformed movement command N2 ′. Maintain constant speed movement. Further, during the constant speed section for synthesizing the deformed movement command N2 ′, the deceleration at the normal deceleration is performed only by the deceleration in the deceleration section of the preceding movement command N1. Then, since the deceleration section of the preceding movement command N1 has already ended during the combined deceleration section of the deformed movement command N2 ′, the deceleration at the normal deceleration is performed only by the deceleration in the combining deceleration section. Done.

Here, returning to FIG. 10A, the conditions for the case where the maximum speed in the movement stroke of the subsequent movement command N2 does not reach the normal constant speed F1 will be described. As described above, the area surrounded by the speed change line of the movement stroke corresponding to one movement command is equivalent to the distance moved by the movement command. In any acceleration zone and deceleration zone including the synthesizing acceleration zone and the synthesizing deceleration zone, the acceleration a representing the magnitude of the gradient of the speed change line is a fixed value.

Therefore, when the time width of the speed increasing section in the moving stroke that reaches the normal constant speed F1 is Ti, as in the preceding movement command N1, the maximum speed of the subsequent movement command N2 is the normal constant speed F1. In order to reach this, only F1 × Ti is required even if the moving distance indicated by the hatched area in FIG. And since it can replace with the time width Ti = F1 / a of a speed-up area, the said minimum moving distance will be F1 < ² > / a. In other words, when the movement distance by the subsequent movement command N2 is shorter than F1 ² / a, the maximum speed in the movement stroke cannot reach the normal constant speed F1, and the speed increasing section and the deceleration having a shorter time width than usual. You will have a section.

Next, a method for calculating the above-described constant velocity for synthesis will be described with reference to FIG. In FIG. 11, on the speed change line in the travel stroke of the movement command N2 ′, the starting point of the synthesizing acceleration section is point A1, the starting point of the synthesizing constant speed section is point A2, and the starting point of the synthesizing deceleration section is pointed A3 and its end point are point A4. On the time axis, a point corresponding to the start of the composite deceleration section is A5, and a time width of the deceleration section in the travel stroke of the preceding movement command N1 is Td. In this case, the area S equivalent to the movement distance of the movement command N2 ′ is a square area surrounded by the points A1, A2, A3, and A5, and a triangular area surrounded by the points A3, A4, and A5. Is the same as the sum of Therefore, the movement distance S = F2 ′ × Td of the movement command N2 ′. And since it can replace with the time width Td = F1 / a of a normal deceleration area, it becomes the said movement distance S = (F1 * F2 ') / a. As a result, it can be calculated by the constant speed for synthesis F2 ′ = (S × a) / F1.

  A control procedure executed by the CPU 111 of the numerical controller 9 in order to realize the contents described above will be described with reference to FIG. This flow is started when the power of the numerical controller 9 is turned on or when a predetermined operation is performed.

  First, in step S5, the CPU 111 of the numerical controller 9 initializes the value of the state flag F to zero. The state flag F is a parameter indicating the execution state of the movement command, and the value is 0 when no movement command is executed and the vehicle is stopped. In addition, this state flag F has a value of 1 when only the current command, which is the last read movement command, is moving, and only when the previous command, which is the previous movement command, is moving. Then the value is 2. Further, the value of the status flag F is 3 when the previous command and the current command are combined and moved.

  Next, the process proceeds to step S10, and the CPU 111 of the numerical controller 9 reads the next movement command from the NC program decoding unit 201.

  Next, moving to step S15, the CPU 111 of the numerical controller 9 determines whether or not a movement command as a positioning command has been read in the procedure of step S10. If the movement command cannot be read, the determination is not satisfied and the routine goes to Step S100. On the other hand, if the movement command can be read, the determination is satisfied, and the routine goes to the next Step S20.

  In step S20, the CPU 111 of the numerical controller 9 determines whether or not the value of the state flag F is 0 at this time. In other words, in step S20, it is determined whether or not the vehicle is in a stopped state. If the value of the status flag F is 0, the determination is satisfied, and the routine goes to Step S25.

  In step S25, the CPU 111 of the numerical controller 9 sets the movement command last read in the procedure of step S10 as the current command. At this time, the current command execution parameter is also set corresponding to the content of the current command. Then, in the next step S30, the value of the state flag F is set to 1, and the state is set to execute the movement only with the current command, and then the process proceeds to step S100.

  On the other hand, in the determination of step S20, if the value of the state flag F is other than 0, the determination is not satisfied, that is, it is considered that movement by execution of some movement command has already been performed. Then, the process proceeds to the next step S35.

  In step S35, the CPU 111 of the numerical controller 9 sets the current command as the previous command at that time, and sets the movement command read last in the procedure of step S10 as the current command. At this time, the current command execution parameter setting content up to that point is transferred to the previous command execution parameter as it is, and the current command execution parameter is also set in accordance with the content of the new current command.

  Next, the process proceeds to step S40, where it is determined whether or not both the previous command and the current command are movement commands in the same direction. In other words, in step S40, it is determined whether the previous command and the current command can be combined. When the previous command and the current command are movement commands in directions different from each other, the determination is not satisfied, that is, it is considered that the previous command and the current command cannot be combined and connected. Then, the process proceeds to step S45, the value of the state flag F is set to 2, and the state is set to move only by the previous command, and then the process proceeds to step S100.

  On the other hand, if it is determined in step S40 that the previous command and the current command are both movement commands in the same direction, the determination is satisfied, that is, the previous command and the current command are considered to be combined. Then, the process proceeds to next Step S50.

In step S50, the CPU 111 of the numerical controller 9 determines whether or not the maximum speed reaches the normal constant speed F1 in the travel stroke according to the current command. As described above, this is determined based on whether or not the moving distance according to the current command is shorter than F1 ² / a. If the moving distance according to the current command is equal to or greater than F1 ² / a, the determination is satisfied, that is, it is considered that the combined connection with the previous command is possible without changing the moving stroke of the current command, and the process proceeds to step S60. On the other hand, if the moving distance by the current command is shorter than F1 ² / a, the determination is not satisfied, that is, it is considered that the previous command cannot be combined and connected unless the moving stroke of the current command is changed, and the process proceeds to the next step S55.

  In step S55, the CPU 111 of the numerical controller 9 calculates the composition constant speed F2 ′ corresponding to the current command by (S × a) / F1 described above, and sets the constant speed section speed in the current command execution parameter. The composite constant speed F2 ′ is set and the process proceeds to step S60.

  In step S60, the CPU 111 of the numerical controller 9 sets the value of the state flag F to 3 and sets the previous command and the current command to be connected and moved, and then proceeds to step S100.

  In step S100, the CPU 111 of the numerical control device 9 causes the current input voltage calculation unit 204 and the previous input voltage calculation unit 203 to calculate the values of the input voltages corresponding to the value of the state flag F, respectively, and sums them. A movement control process for outputting a value to the servo control unit is performed (see FIG. 13 described later).

  Next, the process proceeds to step S65, and the CPU 111 of the numerical controller 9 determines whether or not an operation for ending this flow has been performed via a keyboard 130 or the like of an operation panel (not shown). If the end operation has been performed, the determination in step S65 is satisfied, and this flow ends. On the other hand, if the end operation has not been performed, the determination at step S65 is not satisfied, and the routine goes to the next step S70.

  In step S70, the CPU 111 of the numerical controller 9 determines whether or not the value of the status flag F is 0 at this time. In other words, in step S70, it is determined whether or not the vehicle is in a stopped state. If the value of the status flag F is 0, the determination is satisfied, the process returns to step S10, and the same procedure is repeated. On the other hand, if the value of the status flag F is other than 0, the process proceeds to the next step S75.

  In step S75, the CPU 111 of the numerical controller 9 determines whether or not the travel stroke by the current command is immediately before starting the deceleration zone. In other words, in step S75, a movement command next to the current command is read, and it is determined whether or not it is time to check whether it can be combined with the current command. If the current command is just before starting the deceleration zone, the determination is satisfied, the routine returns to step S10, and the same procedure is repeated. On the other hand, if the current command is not immediately before starting the deceleration zone, the determination is not satisfied and the routine goes to the next step S80.

  In step S80, the CPU 111 of the numerical controller 9 determines whether or not the value of the status flag F is 1 at this time. In other words, in step S70, it is determined whether or not the vehicle is moving only by the current command. If the value of the status flag F is 1, the determination is satisfied, and the process proceeds to the movement control process in step S100 as it is and only the execution of the current command is continued. On the other hand, if the value of the status flag F is not 1, the process proceeds to the next step S85.

  In step S85, the CPU 111 of the numerical control device 9 determines whether or not the travel process according to the previous command has been completed. If the previous command has not yet ended, the determination is not satisfied, and the process proceeds to the movement control process in step S100 as it is, and the execution of the same previous command alone or the combined connection of the previous command and the current command is continued. On the other hand, if the previous command has been completed, the determination is satisfied, the previous command and the previous command execution parameter are deleted in the next step S90, the value of the status flag F is set to 1 in step S30, and the process proceeds to step S100. Only the command is executed this time.

  The detailed procedure of the movement control process executed in step S100 in FIG. 12 is shown in FIG.

  First, in step S105, the CPU 111 of the numerical controller 9 determines whether or not the value of the status flag F is 0 at this time. In other words, in step S105, it is determined whether or not the vehicle is in a stopped state. If the value of the status flag F is 0, the determination is satisfied and this flow is ended as it is. On the other hand, if the value of the status flag F is other than 0, the determination is not satisfied, that is, it is considered that movement by execution of some movement command is already being performed, and the process proceeds to the next step S110.

  In step S110, the CPU 111 of the numerical controller 9 determines whether or not the value of the status flag F is 2 at this time. In other words, in step S105, although the previous command and the current command are read, they cannot be combined and connected, and at this time, the movement is executed only by the previous command and the current command is waited. It is determined whether or not it is in a state. If the value of the status flag F is 2, the determination is satisfied, and after the current input voltage value is set to 0 in step S115, the process proceeds to step S145. On the other hand, if the value of the status flag F is not 2, the determination is not satisfied, and the routine goes to the next step S120.

  In step S120, the CPU 111 of the numerical controller 9 determines whether or not the current instruction has not yet started. In other words, in step S120, it is determined whether or not the current process execution parameter command start time is not yet set. If the current instruction has already started, the determination is not satisfied and the routine goes directly to step S135. On the other hand, if the current instruction has not yet started execution, the determination is satisfied, and the routine goes to the next Step S125.

  In step S125, the CPU 111 of the numerical controller 9 sets the current process execution parameter command start time to the current time at this time. As a result, the movement stroke of the movement command set in the current command at this time is performed in the speed-up zone, the constant-speed zone, and the deceleration zone in this order starting from this command start time.

  Next, the process proceeds to step S135, where the CPU 111 of the numerical controller 9 corresponds to the current travel process based on the current process execution parameter command start time and the constant speed section speed setting in the current input voltage calculation unit 204. Calculate the input voltage value.

  Next, the process proceeds to step S140, and the CPU 111 of the numerical controller 9 determines whether or not the value of the state flag F is 1 at this time. In other words, in step S140, it is determined whether or not the movement is being executed only by the current command. If the value of the status flag F is not 1, the determination is not satisfied, and the routine goes to the next Step S145.

  In step S145, the CPU 111 of the numerical controller 9 determines the current input voltage corresponding to the travel process at this time based on the previous process execution parameter command start and the constant speed section speed setting in the previous input voltage calculation unit 203. Calculate the value.

  Next, the process proceeds to step S150, where the CPU 111 of the numerical controller 9 calculates the sum of the values of the previous input voltage and the current input voltage at this time as the servo input voltage, and in the next step S155, the servo input voltage is servoed. Input to the control unit controls the drive of each of the shaft motors 15, 131, 132. Then, this flow ends.

  On the other hand, if the value of the status flag F is 1 in the determination in step S140, the determination is satisfied, and the process proceeds to step S165 after setting the previous input voltage value to 0 in the next step S160.

  In step S165, the CPU 111 of the numerical control device 9 determines whether or not the travel process based on the current command has been completed. If the current command has not been completed yet, the determination is not satisfied and the routine goes directly to step S150. On the other hand, if the current command has been completed, the determination is satisfied, and in the next step S170, the current command and the current command execution parameter are deleted, the value of the state flag F is set to 0, and the process proceeds to step S150.

  By executing the above flow, if the value of the status flag is 0 in the procedure of step S150, the servo input voltage is calculated as 0. If the value of the status flag is 1, the servo input voltage is calculated using only the current input voltage calculated in step S135. If the value of the status flag is 2, the servo input voltage is calculated using only the previous input voltage calculated in step S145. When the value of the status flag is 3, the servo input voltage is calculated by the sum of the current input voltage calculated in step S135 and the previous input voltage calculated in step S145. Thus, the servo input voltage is calculated corresponding to each value of the status flag, and the drive of each of the shaft motors 15, 131, 132 is controlled.

  In the above, the procedure of step S145 in the flow of FIG. 13 functions as the first speed calculation means, the procedure of step S135 functions as the second speed calculation means, and the procedure of step S150 functions as the speed synthesis means. The procedure of step S75 in the flow of FIG. 12 functions as a deceleration start determination unit, the procedure of step S10 functions as an acquisition unit, the procedure of step S40 functions as a determination unit, and the procedure of step S50 functions as a speed determination unit. And the procedure of step S55 functions as a changing means.

  As described above, in the present embodiment, it is determined whether or not the current command can reach the normal constant velocity based on the movement amount of the current command and the fixed acceleration (step S50). If it is determined that the normal constant speed cannot be reached, it is assumed that the deceleration in the deceleration section due to the combined command may be excessively increased, and the constant speed section is changed (step S55). The execution speed per unit time of the current command is calculated based on the changed constant speed section speed (step S135), and in step S150, the execution speed calculated in step S135 and the execution speed calculated in step S145 are combined. To do. As a result, it is possible to prevent the deceleration in the deceleration section from becoming excessively large as described above. As a result, the soundness of the machine tool can be maintained and the machine tool can be operated safely.

  In this embodiment, in particular, when the movement amount of the current command is equal to or larger than the movement amount of the previous command, the normal constant speed is reached by a command in which these two commands are combined and connected as usual. Positioning control can be performed (see the flow from step S50 to step S60).

  In this embodiment, in particular, after the previous command in the Z-axis direction for positioning the spindle head 6 to the Z-axis origin which is the tool change preparation position, in step S10, the Z-axis origin is above or below the Z-axis origin. The current command in the Z-axis direction for positioning to the position is fetched. In step S40, it is determined whether the up / down direction of the previous command in the Z-axis direction matches the up / down direction of the current command in the Z-axis direction. In step S50, it is determined whether or not the current command in the Z-axis direction can reach a normal constant speed in the Z-axis direction.

  As a result, when the tool is changed, when moving upward with the Z-axis origin sandwiched, or when moving downward with the Z-axis origin sandwiched, adverse effects due to large deceleration can be prevented. That is, the combined deceleration of the previous command to the Z-axis origin and the current command from the Z-axis origin can prevent the deceleration in the deceleration zone from becoming excessively large. In particular, in the case of tool change, the spindle head 6 may engage with the tool changer 2. When the spindle head 6 and the tool changer 2 are engaged, if the spindle head 6 moves at a large deceleration, there is a problem that the tool changer 2 is damaged. In the above embodiment, the spindle head 6 does not move with a large deceleration, so that the tool changer 2 is not damaged.

  In the above embodiment, the previous command and the current command are both limited to movement in the Z-axis direction (particularly, tool replacement), but the present invention is not limited to this. That is, as shown in FIG. 14, if the two movement commands N1 and N2 are continuous in the same positive or negative direction along a plurality of axes, the method of the present invention is applied in the same manner as described above. can do.

  The tool changer 2 is not limited to that of the above-described embodiment, and may be any device that moves the spindle head 6 for tool change.

  In the above embodiment, the tool change preparation position is a position at which the spindle head 6 that is the Z-axis origin position is attached to the tool changer 2 and the cutting tool 7 attached to the spindle 22 is attached to the tool changer 2. Although the mounted cutting tool 7 is a position for mounting on the main shaft 22, it may be a position below the Z-axis origin position. The Z-axis origin position may be a position immediately before the spindle head 6 and the tool changer 2 are engaged. In this case, the main shaft 22 is in a state in which the cutting tool 7 is mounted.

1 Machine Tool 6 Spindle Head 15 Z-axis Motor 22 Spindle 23 Spindle Motor 111 CPU
131 X-axis motor 132 Y-axis motor 201 NC program decoding unit 202 Movement command execution unit 203 Previous input voltage calculation unit 204 Current input voltage calculation unit 205 Servo control unit 301 NC program

Claims (5)

In a numerical control device that controls the positioning of a tool or a workpiece at a position designated by a positioning command including a moving direction and a moving amount based on a predetermined acceleration and speed,
First speed calculation means for calculating an execution speed per unit time of the positioning command;
Deceleration start determination means for determining whether the execution speed of the current positioning command calculated by the first speed calculation means is a speed immediately before the start of deceleration;
When the execution start speed is determined by the deceleration start determination means to be a speed immediately before the start of deceleration, a capture means for fetching the next command;
The next instruction fetched by said fetching means includes a judgment means for judging whether or not a positioning command, and said a positioning command for the current positioning command in the same direction,
Whether the If current positioning command and the next positioning command is determined to be a positioning command for the same direction, can reach speeds the next positioning command is the predetermined by the determination unit, the following Speed determining means for determining on the basis of the amount of movement of the positioning command and the predetermined acceleration;
When the speed determining means determines that the next positioning command cannot reach the predetermined speed, the predetermined speed is changed based on the acceleration and the movement amount of the next positioning command. Change means to
Second speed calculating means for calculating an execution speed per unit time of the next positioning command based on the speed changed by the changing means;
Speed synthesis means for synthesizing the execution speed calculated by the first speed calculation means and the execution speed calculated by the second speed calculation means ;
Equipped with a,
The speed synthesizing means starts a synthesizing speed increase based on the execution speed calculated by the second speed calculation means at the start of deceleration by the execution speed calculated by the first speed calculation means, and generates a predetermined constant speed for synthesis. The speed is continuously increased at a constant constant speed for synthesis, and when the deceleration at the execution speed calculated by the first speed calculation means is completed, the deceleration for synthesis is started and decelerated. A numerical control device for a machine tool. In the numerical control device of the machine tool according to claim 1,
When it is determined by the speed determining means that the next positioning command can reach the predetermined speed, the second speed calculating means determines the unit time of the next positioning command based on the predetermined speed. A numerical control device for a machine tool, characterized by calculating a hit execution speed. In the numerical control device of the machine tool according to claim 1 or claim 2,
The machine tool includes a column, a spindle head supported movably on the column, a spindle supported rotatably on the spindle head and capable of mounting the tool on a lower end, and a tool changer provided on the column. And
The current positioning command is a tool change that is a position where the spindle head is attached to the tool changer with a tool attached to the spindle, or a position where a tool attached to the tool changer is attached to the spindle. It is a command to position to the preparation position.
The numerical control device for a machine tool, wherein the next positioning command fetched by the take-in means is a command for positioning the spindle head from the tool change preparation position to a position above or below the tool change preparation position. A control method for a machine tool, which controls positioning of a tool or a workpiece at a position instructed by a positioning command including a moving direction and a moving amount based on a predetermined acceleration and speed,
A first speed calculation procedure for calculating an execution speed per unit time of the positioning command;
A deceleration start determination procedure for determining whether or not the execution speed of the current positioning command calculated in the first speed calculation procedure is a speed immediately before the start of deceleration;
If it is determined in the deceleration start determination procedure that the execution speed is the speed immediately before the start of deceleration, a capture procedure for fetching the next command;
Wherein the next captured by capture procedure command is a positioning command, the procedure determines which and the determining whether a positioning command for the current positioning command in the same direction,
Wherein if said current positioning command at decision procedure and the subsequent positioning command is determined to be positioning command for the same direction, whether it can reach speeds the next positioning command is the predetermined said A speed determination procedure for determining based on the amount of movement of the next positioning command and the predetermined acceleration;
When it is determined in the speed determination procedure that the next positioning command cannot reach the predetermined speed, the predetermined speed is calculated based on the acceleration and the movement amount of the next positioning command. Change procedure to change,
A second speed calculation procedure for calculating an execution speed per unit time of the next positioning command based on the speed changed in the change procedure;
A speed synthesis procedure for synthesizing the execution speed calculated in the first speed calculation procedure and the execution speed calculated in the second speed calculation procedure ;
Equipped with a,
In the speed synthesis procedure, at the start of deceleration by the execution speed calculated in the first speed calculation procedure, the composition speed increase by the execution speed calculated in the second speed calculation procedure is started to reach a predetermined constant speed for synthesis. in terms of the speed increasing until, Rukoto decelerate subsequently moved at a constant rate over synthetic for a constant velocity speed, to start the synthesis deceleration when deceleration by execution speed computed by the first speed calculation procedure is completed A control method of a machine tool characterized by the above. On the computer,
A first speed calculation procedure for calculating an execution speed per unit time of a positioning command for instructing a position for positioning control of a tool or a workpiece based on a predetermined acceleration and speed, including a moving direction and a moving amount. When,
A deceleration start determination procedure for determining whether or not the execution speed of the current positioning command calculated in the first speed calculation procedure is a speed immediately before the start of deceleration;
If it is determined in the deceleration start determination procedure that the execution speed is the speed immediately before the start of deceleration, a capture procedure for fetching the next command;
Wherein the next captured by capture procedure command is a positioning command, the procedure determines which and the determining whether a positioning command for the current positioning command in the same direction,
Wherein if said current positioning command at decision procedure and the subsequent positioning command is determined to be positioning command for the same direction, whether it can reach speeds the next positioning command is the predetermined said A speed determination procedure for determining based on the amount of movement of the next positioning command and the predetermined acceleration;
When it is determined in the speed determination procedure that the next positioning command cannot reach the predetermined speed, the predetermined speed is calculated based on the acceleration and the movement amount of the next positioning command. Change procedure to change,
A second speed calculation procedure for calculating an execution speed per unit time of the next positioning command based on the speed changed in the change procedure;
A speed synthesis procedure for synthesizing the execution speed calculated in the first speed calculation procedure and the execution speed calculated in the second speed calculation procedure ;
With the execution,
In the speed synthesis procedure, at the start of deceleration by the execution speed calculated in the first speed calculation procedure, the composition speed increase by the execution speed calculated in the second speed calculation procedure is started to reach a predetermined constant speed for synthesis. Is continuously moved at the constant speed for synthesis, and when the deceleration at the execution speed calculated by the first speed calculation procedure is completed, the deceleration for synthesis is started and the deceleration is executed . Machine tool control program for.

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