Control device, control method, and computer program

Abstract

To provide a control device, a control method, and a computer program capable of suppressing an occurrence of vibration of a tool magazine when indexing a tool at a replacement position.SOLUTION: A control device of a machine tool for controlling the drive of a tool magazine for storing a plurality of tools, and replacing a tool mounted on a main shaft with a tool stored in the tool magazine includes: an acceleration part for accelerating the tool magazine at a first acceleration when indexing a predetermined tool stored in the tool magazine at a replacement position after the tool is removed from the main shaft; and a deceleration part for decelerating the tool magazine at a second acceleration after the acceleration in the acceleration part is finished. At least one of a first condition that the magnitude of a maximum value of the second acceleration is smaller than the magnitude of a maximum value of the first acceleration, and a second condition that the magnitude of a maximum value of a second jerk, which is a time differential of the second acceleration, is smaller than the magnitude of a maximum value of a first jerk, which is a time differential of the first acceleration is satisfied.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present technology relates to a control device, a control method, and a computer program for controlling the drive of a tool magazine that stores a plurality of tools. [Background technology]

[0002] A machine tool includes, for example, a disk-shaped tool magazine and a spindle. The tool magazine includes a plurality of storage sections for storing tools, and the storage sections are arranged in a circumferential direction on the periphery of the tool magazine. Therefore, by increasing the diameter of the tool magazine, the number of tools that can be stored increases (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-264234 Summary of the Invention [Problem to be solved by the invention]

[0004] As the diameter of the tool magazine increases, the moment of inertia acting on the tool magazine during operation also increases, and the tool magazine also vibrates. When replacing a tool attached to the spindle, the tool magazine indexes the storage section that stores the specified tool to the replacement position. If the storage section indexed to the replacement position vibrates, the position of the tool stored in the storage section and the spindle will not match, and the tool may not be able to be attached to the spindle.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a control device, a control method, and a computer program that can suppress the occurrence of vibrations in a tool magazine when indexing a tool to a replacement position. [Means for solving the problem]

[0006] A control device according to one embodiment of the present disclosure is a control device for a machine tool that controls the drive of a tool magazine storing a plurality of tools and replaces a tool attached to a spindle with a tool stored in the tool magazine.When a specific tool stored in the tool magazine is indexed to a replacement position after a tool is removed from the spindle, the control device includes an acceleration unit that accelerates the tool magazine at a first acceleration and a deceleration unit that decelerates the tool magazine at a second acceleration after acceleration by the acceleration unit ends, and satisfies at least one of a first condition that the maximum magnitude of the second acceleration is smaller than the maximum magnitude of the first acceleration and a second condition that the maximum magnitude of the second jerk, which is the time derivative of the second acceleration, is smaller than the maximum magnitude of the first jerk, which is the time derivative of the first acceleration.

[0007] In the present disclosure, at least one of the first condition and the second condition is satisfied, and the occurrence of vibrations in the tool magazine is suppressed when a tool is indexed to a replacement position.

[0008] A control device according to an embodiment of the present disclosure satisfies either the first condition or the second condition.

[0009] In the present disclosure, it is possible to both suppress the occurrence of vibration in the tool magazine and shorten the time required to index the tool to the replacement position.

[0010] A control device according to an embodiment of the present disclosure satisfies both the first and second conditions.

[0011] In the present disclosure, the occurrence of vibrations in the tool magazine when a tool is indexed to a replacement position is reliably suppressed.

[0012] A control device according to one embodiment of the present disclosure includes a selection unit that selects one acceleration waveform from a plurality of acceleration waveforms relating to the second acceleration based on the magnitude of the maximum speed of the tool magazine.

[0013] In the present disclosure, one acceleration waveform is selected from a plurality of acceleration waveforms relating to the second acceleration based on the magnitude of the maximum speed of the tool magazine.

[0014] In one embodiment of the control device of the present disclosure, the multiple acceleration waveforms include a first waveform having a period in which acceleration is constant and a second waveform in which acceleration is not constant, and the control device is equipped with a judgment unit that judges whether the maximum velocity is equal to or greater than a threshold value determined by a maximum value of the second acceleration, and the selection unit selects the first waveform when the judgment unit determines that the maximum velocity is equal to or greater than the threshold value, and selects the second waveform when the judgment unit determines that the maximum velocity is not equal to or greater than the threshold.

[0015] In the present disclosure, if it is determined that the maximum speed is equal to or greater than the threshold, a first waveform is selected, and if it is determined that the maximum speed is not equal to or greater than the threshold, a second waveform is selected.

[0016] A control device according to an embodiment of the present disclosure includes a calculation unit that calculates the threshold value based on a maximum acceleration and a maximum jerk during deceleration of the tool magazine.

[0017] In the present disclosure, the threshold value is calculated to realize appropriate waveform selection.

[0018] A control device according to an embodiment of the present disclosure includes a setting unit that sets a maximum acceleration and a maximum jerk during deceleration of the tool magazine.

[0019] In the present disclosure, an operator can appropriately set the maximum acceleration and maximum jerk during deceleration according to the specifications of the tool magazine.

[0020] A control method according to one embodiment of the present disclosure is a control method for a machine tool that controls the drive of a tool magazine that stores a plurality of tools and replaces a tool attached to a spindle with a tool stored in the tool magazine, and when a specific tool stored in the tool magazine is indexed to a replacement position after a tool is removed from the spindle, the tool magazine is accelerated at a first acceleration, and after acceleration ends, the tool magazine is decelerated at a second acceleration, and at least one of a first condition that the maximum magnitude of the second acceleration is smaller than the maximum magnitude of the first acceleration and a second condition that the maximum magnitude of a second jerk, which is a time derivative of the second acceleration, is smaller than the maximum magnitude of a first jerk, which is a time derivative of the first acceleration.

[0021] In the present disclosure, the magnitude of the maximum value of the second acceleration is made smaller than the magnitude of the maximum value of the first acceleration during tool replacement, or the magnitude of the maximum value of the second jerk is made smaller than the magnitude of the maximum value of the first jerk during tool replacement.

[0022] A computer program according to an embodiment of the present disclosure is a computer program executable by a control device of a machine tool that controls the drive of a tool magazine storing a plurality of tools and replaces a tool attached to a spindle with a tool stored in the tool magazine, the computer program causing the control device to execute a process of accelerating the tool magazine at a first acceleration and, after the acceleration ends, decelerating the tool magazine at a second acceleration when indexing a specific tool stored in the tool magazine to a replacement position after removing a tool from the spindle, and satisfies at least one of a first condition that a maximum value of the second acceleration is smaller than a maximum value of the first acceleration and a second condition that a maximum value of a second jerk, which is a time derivative of the second acceleration, is smaller than a maximum value of a first jerk, which is a time derivative of the first acceleration.

[0023] In the present disclosure, the magnitude of the maximum value of the second acceleration is made smaller than the magnitude of the maximum value of the first acceleration during tool replacement, or the magnitude of the maximum value of the second jerk is made smaller than the magnitude of the maximum value of the first jerk during tool replacement. Effect of the Invention

[0024] In the control device, control method, and computer program according to one embodiment of the present disclosure, by satisfying at least one of a first condition for making the maximum value of the second acceleration smaller than the maximum value of the first acceleration and a second condition for making the maximum value of the second jerk smaller than the maximum value of the first jerk during tool replacement, it is possible to suppress the occurrence of vibration in the tool magazine when indexing a tool to a replacement position. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic perspective view of a machine tool. [Diagram 2] FIG. 2 is a block diagram of a machine tool. [Diagram 3] 11 is a graph showing a first speed waveform showing the relationship between speed and time of a magazine motor when a specific tool is indexed to a replacement position, and a first acceleration waveform showing the relationship between acceleration and time. [Figure 4] 13 is a graph showing a second speed waveform showing the relationship between speed and time of the magazine motor when a specific tool is indexed to a replacement position, and a second acceleration waveform showing the relationship between acceleration and time. [Diagram 5] 11 is a graph showing an acceleration waveform for explaining a threshold velocity. [Figure 6] FIG. 4 is an enlarged view showing a first velocity waveform and a first acceleration waveform during a deceleration period. [Figure 7] FIG. 4 is an enlarged view showing a second velocity waveform and a second acceleration waveform during a deceleration period. [Figure 8] 10 is a flowchart illustrating speed processing of the tool magazine by the control device. [Figure 9] 10 is a flowchart illustrating speed processing of the tool magazine by the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present invention will be described below with reference to the drawings showing a machine tool according to an embodiment. In the following description, up, down, front, back, left and right in the drawings will be used. Figure 1 is a simplified perspective view of a machine tool 1. The machine tool 1 has a rectangular base 2 extending in the front-to-rear direction. A pillar 3 is provided at the rear of the upper surface of the base 2. A control device 4 is provided at the rear surface of the pillar 3, and a spindle head 5 is provided at the front surface of the pillar 3. The spindle head 5 is movable in the vertical direction.

[0027] The spindle head 5 has a spindle (not shown) that extends vertically. A tool is attached to the lower end of the spindle. A spindle motor 6 that rotates the spindle is provided at the upper end of the spindle head 5. A tool magazine 7 is provided at the vertical midpoint of the upright 3 via two connecting plates 8. The two connecting plates 8 protrude forward from the upright 3 and are aligned on the left and right. The tool magazine 7 is fixed to the front ends of the two connecting plates 8. The tool magazine 7 is, for example, a turret-type tool magazine 7, and stores a plurality of tools. The tool magazine 7 is located forward of the spindle head 5. The control device 4 rotates the tool magazine 7 by driving the magazine motor 7a (see FIG. 2) to index the tool to a predetermined position, and drives the Z-axis motor 5a (see FIG. 2) to lower the spindle head 5 and attach the tool to the spindle. The control device 4 also drives the Z-axis motor 5a to raise the spindle head 5, remove the tool from the spindle, and store it in the tool magazine 7.

[0028] A holding device 11 for holding a workpiece is provided at the front of the upper surface of the base 2. The holding device 11 includes a first moving table 9 and a second moving table 10. The first moving table 9 is provided on the second moving table 10. The first moving table 9 moves left and right by being driven by an X-axis motor 9a (see FIG. 2). The second moving table 10 moves forward and backward by being driven by a Y-axis motor 10a (see FIG. 2). The first moving table 9 moves forward and backward by the movement of the second moving table 10.

[0029] 2 is a block diagram of the machine tool 1. The control device 4 includes a CPU 4a, a RAM 4b, a storage unit 4c, and an interface 4d. The storage unit 4c has, for example, a non-volatile memory, a hard disk, etc. The non-volatile memory is, for example, an EPROM, an EEPROM, etc. The storage unit 4c stores a control program (program product) for the machine tool 1. The control program includes a program for controlling the drive of the tool magazine 7. The storage unit 4c stores a magnitude A of maximum acceleration of the magazine motor 7a during acceleration, which will be described later. k , the jerk J of the magazine motor 7a during acceleration k , the magnitude of maximum acceleration of the magazine motor 7a during deceleration A g , the jerk J of the magazine motor 7a during deceleration g , the maximum speed V of the magazine motor 7a max The control program may be stored in a portable storage medium 4e that stores the control program, and the control program may be installed in the storage unit 4c from the storage medium 4e, or the control device 4 may be configured to be capable of communication, and the control program may be downloaded from a server to the storage unit 4c. The jerk is a value obtained by differentiating the acceleration with respect to time (time differential value).

[0030] The CPU 4a reads out a control program from the storage unit 4c to the RAM 4b, and outputs drive signals based on the control program to the X-axis motor 9a, the Y-axis motor 10a, the Z-axis motor 5a, the spindle motor 6, or the magazine motor 7a via the interface 4d and the drive circuits 9b, 10b, 5b, 6b, or 7b. Each motor has an encoder, which transmits a detection value to the drive circuit. The drive circuit receives the detection value from the encoder and performs feedback control. The operator operates the operation unit 20, which inputs information to the control device 4 via the interface 4d. The operation unit 20 has a keyboard, a touch panel, switches, or the like.

[0031] When replacing a tool attached to the spindle, after the tool is removed from the spindle, the magazine motor 7a accelerates up to its maximum speed, maintains the maximum speed for a predetermined period of time, and then decelerates to index the specified tool stored in the tool magazine 7 to the replacement position.

[0032] FIG. 3 is a graph showing a first velocity waveform showing the relationship between the speed and time of the magazine motor 7a when a predetermined tool is indexed to a replacement position, and a first acceleration waveform showing the relationship between the acceleration and time. max indicates the maximum speed of the magazine motor 7a. 0 indicates the time when the magazine motor 7a starts accelerating, and T k indicates the end point of acceleration of the magazine motor 7a. The speed at the start of acceleration is 0. s indicates the time when the magazine motor 7a starts to decelerate, and T e indicates the end point of deceleration of the magazine motor 7a. k The period between T k From T s During this period, the maximum speed is maintained, and T s From T e The period between the acceleration and deceleration periods is a deceleration period of the magazine motor 7a. The acceleration during the acceleration period corresponds to the first acceleration, and the acceleration during the deceleration period corresponds to the second acceleration. The control device 4 that controls the magazine motor 7a during the acceleration period corresponds to the acceleration section, and the control device 4 that controls the magazine motor 7a during the deceleration period corresponds to the deceleration section. Note that even during the minimum travel distance, which is travel to a tool storage position next to the tool magazine 7, the magazine motor 7a reaches its maximum speed.

[0033] A k indicates the magnitude of the maximum acceleration of the magazine motor 7a during acceleration, and J k indicates the maximum jerk of the magazine motor 7a during acceleration. g indicates the magnitude of the maximum acceleration of the magazine motor 7a during deceleration, and J g indicates the maximum jerk of the magazine motor 7a during deceleration. g A k Less than. A k corresponds to the maximum value of the first acceleration, and A g corresponds to the maximum value of the second acceleration. g J k Less than. J k corresponds to the maximum value of the first jerk, and J gcorresponds to the maximum value of the second jerk. As shown in the lower diagram of FIG. 3, the acceleration waveform during the deceleration period forms an isosceles trapezoid with a period during which the acceleration is constant. The area of ​​the isosceles trapezoid is the maximum velocity V max The acceleration waveform that forms an isosceles trapezoidal shape corresponds to the first waveform.

[0034] 4 is a graph showing a second velocity waveform showing the relationship between the velocity and time of the magazine motor 7a when a specific tool is indexed to the replacement position, and a second acceleration waveform showing the relationship between the acceleration and time. As shown in the lower diagram of FIG. 4, the acceleration waveform during the deceleration period forms an isosceles triangle shape in which there is no period in which the acceleration is constant. The area of ​​the isosceles triangle is the maximum speed V max The magnitude of the acceleration waveform that forms an isosceles triangle corresponds to the second waveform. max , 0, T k , T s , A k , J k , J g is the same as in FIG. 3, and detailed description thereof will be omitted.

[0035] When a specific tool is indexed to the replacement position, the speed waveform and acceleration waveform of the magazine motor 7a become the first speed waveform and first acceleration waveform in FIG. 3, or the second speed waveform and second acceleration waveform in FIG.

[0036] A method for determining whether the acceleration waveform during the deceleration period is an isosceles trapezoid or an isosceles triangle will be described. FIG. 5 is a graph showing an acceleration waveform for explaining the threshold speed. As shown in FIG. 5, the acceleration waveform during the deceleration period forms an isosceles triangle shape that protrudes to the negative side, and the magnitude of the inclination of the equilateral side is J. g And the peak of the acceleration waveform is -A g Then, the area of ​​the acceleration waveform is equal to or smaller than the threshold velocity V s The threshold speed V s A g and J. g Therefore, the A stored in the memory unit 4c can be calculated from g , J g and V maxThis determines whether the acceleration waveform during the deceleration period will be an isosceles trapezoid or an isosceles triangle.

[0037] Maximum speed V max ≧ threshold speed V s In this case, as shown in the lower diagram of Figure 3, the acceleration waveform during the deceleration period forms an isosceles trapezoidal shape that protrudes to the negative side, and the minimum value of acceleration is -A g The maximum speed is V max < Threshold speed V s In this case, as shown in the lower diagram of Figure 4, the acceleration waveform during the deceleration period forms an isosceles triangle shape that protrudes to the negative side, and the minimum value of acceleration is -A g Therefore, the maximum speed V max and threshold velocity V s By comparing these, it is possible to determine whether the acceleration waveform during the deceleration period is an isosceles trapezoid or an isosceles triangle.

[0038] FIG. 6 is an enlarged view showing the first velocity waveform and the first acceleration waveform during the deceleration period. m is time T s and time T e At the midpoint between s and T m The time between time T m and T e It is equal to the time between time T m The speed at is V max / 2. L1 in Figure 6 has a velocity V max / 2, and L2 is the time T s L3 is the line that indicates the time T m L4 is the line indicating the time T e The region surrounded by the first velocity waveform, line L1, and line L2 is a first region 31, the region surrounded by the time axis, line L1, line L2, and line L3 is a second region 32, and the region surrounded by the time axis, line L3, and the first velocity waveform is a third region 33.

[0039] The area of ​​the region surrounded by the line L1, the line L4, and the first velocity waveform is equal to the area of ​​the first region 31. That is, the total area of ​​the first region 31, the second region 32, and the third region 33 is Vmax / 2 and time T s and time T e This sum of areas is equal to the product of the first moving distance L of the magazine motor 7a during the deceleration period. gen1 , that is, corresponds to the moving distance of the tool magazine 7.

[0040] T in Figure 6 m1 is at time T s From time t 1 Indicates the time that has passed, T m2 is at time T m1 From time t 2 Indicates the time that has passed. Time T m2 and time T e The time between is time t 1 At time T s and time T m1 The slope of the first acceleration waveform between g The first acceleration is at time T s From time T m1 From 0 to -A g It decreases linearly until the time T m1 and time T m2 Between the first acceleration waveform slope is 0 and the first acceleration is -A g At time T m2 and time T e Between these, the slope of the first acceleration waveform is J g The first acceleration is at time T m2 From time T e Up to -A g increases linearly from to 0.

[0041] A g / t 1 =J g , V max =A g ·t 1 +A g ·t 2 Therefore, at time T s and T m Time between = 2t 1 +t 2 =V max / A g +A g / Jg Therefore, the first moving distance L gen1 =(V max / A g +A g / J g )·V max / 2. t 1 =A g / J g and t 2 =(V max -A g ?t 1 ) / A g It is.

[0042] FIG. 7 is an enlarged view showing the second velocity waveform and the second acceleration waveform during the deceleration period. m , line L1, line L2, line L3, line L4, first region 31, second region 32, and third region 33 are the same as those in FIG. 6, and detailed description thereof will be omitted. The total area of ​​the first region 31, the second region 32, and the third region 33 is V max / 2 and time T s and time T e The total area is equal to the product of the time between the deceleration period and the second movement distance L of the magazine motor 7a during the deceleration period. gen2 , that is, corresponds to the moving distance of the tool magazine 7.

[0043] Time T s and time T m The time between and the time T e and time T m The time between is time t 3 At time T s and time T m Between the two, the slope of the second acceleration waveform is -J g The second acceleration is at time T s From time T m From 0 to -A h A h The size of A g At time T m and time T e Between the two, the slope of the second acceleration waveform is J g The second acceleration is at time T m From time T eUp to -A h increases linearly from to 0.

[0044] A h / t 3 =J g , V max =A h ·t 3 Therefore, t 3 =√(V max / J g ) at time T s and T e Time between = 2t 3 Therefore, the second moving distance L gen2 =V max / 2·2√(V max / J g )=√((V max ) 3 / J g )

[0045] 8 and 9 are flow charts for explaining the speed processing of the tool magazine 7 by the control device 4. The operator operates the operation unit 20 and the maximum acceleration A k , maximum jerk during acceleration J k , maximum acceleration during deceleration A g , maximum jerk during deceleration J g , maximum speed V max The operation unit 20 constitutes a setting unit. The CPU 4a receives the command A from the operation unit 20. k , J k , A g , J g , V max (S1). k , J k , A g , J g , V max The CPU 4a stores A k , J k , A g , J g , V max The CPU 4a may obtain the threshold speed V s The CPU 4a that executes step S2 constitutes a calculation unit.

[0046] CPU4a is the fastest V max is the threshold speed V s It is determined whether or not the maximum speed V max is the threshold speed V s If so (S3: YES), the CPU 4a stores 1 in the variable P (S4). The variable P is a variable for indicating whether it is the first velocity waveform and the first acceleration waveform, or the second velocity waveform and the second acceleration waveform. When P=1, it indicates the first velocity waveform and the first acceleration waveform, and when P=2, it indicates the second velocity waveform and the second acceleration waveform. The RAM 4b or the storage unit 4c stores the variable P.

[0047] CPU4a is the first moving distance L gen1 (S5) Calculate the maximum speed V max is the threshold speed V s If it is not equal to or greater than the first moving distance (S3: NO), the CPU 4a stores 2 in the variable P (S6) and gen2 is calculated (S7).

[0048] After processing step S7, the CPU 4a starts driving the magazine motor 7a (S8). The CPU 4a determines whether the distance between the current position of the magazine motor 7a and the replacement position, that is, the remaining travel distance L, is 0 (S9). If the remaining travel distance L is 0 (S9: YES), the CPU 4a stops the magazine motor 7a (S10) and ends the process.

[0049] If the remaining moving distance L is not 0 (S9: NO), the CPU 4a judges whether the variable P is 1 (S11). If the variable P is 1 (S11: YES), the CPU 4a judges whether the remaining moving distance L is the first moving distance L gen1 It is determined whether the remaining moving distance L is equal to or less than the first moving distance L (S12). gen1 If it is equal to or less than (S12: YES), CPU4a g , J g , V max Using t 1 , t 2 The CPU 4a calculates the calculated t 1 , t2 and A g , J g The CPU 4a decelerates the vehicle so that the acceleration waveform becomes an isosceles trapezoid (S14). The CPU 4a updates the remaining travel distance L (S15) and returns the process to step S9. When the remaining travel distance L becomes the first travel distance L gen1 If the speed V of the magazine motor 7a is not equal to or lower than the maximum speed V max It is determined whether the speed V of the magazine motor 7a is less than the maximum speed V max If it is less than the remaining distance L (S16: YES), the CPU 4a accelerates the magazine motor 7a (S17), updates the remaining travel distance L (S15), and returns the process to step S9.

[0050] The speed V of the magazine motor 7a is the maximum speed V max If the speed V is not less than the maximum speed V max When it reaches, CPU4a will have the maximum speed V max is maintained (S18), the remaining travel distance L is updated (S15), and the process returns to step S9.

[0051] In step S11, if the variable P is not 1 (S11: NO), that is, if the variable P is 2, the CPU 4a determines whether the remaining moving distance L is the second moving distance L gen2 It is determined whether the remaining moving distance L is equal to or less than the second moving distance L (S19). gen2 If the following is true (S19: YES), CPU4a g , V max Using t 3 The CPU 4a calculates the calculated t 3 , A h , J g The acceleration waveform is decelerated so as to have an isosceles triangle shape by using any two of the above (S21). The CPU 4a updates the remaining travel distance L (S15) and returns the process to step S9.

[0052] The remaining travel distance L is the second travel distance L gen2 If the speed V of the magazine motor 7a is not equal to or lower than the maximum speed V maxIt is determined whether the speed V of the magazine motor 7a is less than the maximum speed V max If the speed V of the magazine motor 7a is less than the maximum speed V (S22: YES), the CPU 4a accelerates the magazine motor 7a (S23), updates the remaining moving distance L (S15), and returns the process to step S9. max If it is not less than V (S22: NO), CPU4a operates at the maximum speed V max is maintained (S24), the remaining travel distance L is updated (S15), and the process returns to step S9.

[0053] The acceleration waveform during the acceleration period is an isosceles triangle or an isosceles triangle, similar to the acceleration waveform during the deceleration period. k and the vertex is A k The area of ​​the isosceles triangle projecting to the positive side is the threshold speed V sk Then, the maximum speed V max ≧ threshold speed V sk When this is the case, the acceleration waveform during the acceleration period forms an isosceles trapezoidal shape that protrudes to the positive side, and the maximum value of the acceleration is A k The maximum speed V max < Threshold speed V sk When the acceleration waveform during the acceleration period is an isosceles triangle with a positive protrusion, the maximum value of the acceleration is A k will be smaller than

[0054] In the machine tool according to the embodiment, the maximum acceleration of the magazine motor 7a during deceleration, that is, the maximum value A of the second acceleration g The maximum acceleration of the magazine motor 7a during acceleration, i.e., the maximum value A of the first acceleration k In other words, the first condition is satisfied, and the occurrence of vibration of the tool magazine when the tool is indexed to the tool changing position can be suppressed.

[0055] Also, the second jerk J of the magazine motor 7a during deceleration g The maximum value of the first jerk J of the magazine motor 7a during acceleration is kIn other words, the second condition is satisfied, and the occurrence of vibration of the tool magazine when the tool is indexed to the tool changing position can be suppressed.

[0056] Furthermore, both the first and second conditions are satisfied, and the occurrence of vibration in the tool magazine can be reliably suppressed. Note that only either the first or second condition may be satisfied. In this case, the time required to index the tool to the tool changing position can be shortened compared to when both the first and second conditions are satisfied, so that it is possible to both suppress the occurrence of vibration in the tool magazine and shorten the time required to index the tool to the tool changing position. When both the first and second conditions are satisfied, the time required to index the tool to the tool changing position is longer compared to when only either the first or second condition is satisfied, but the occurrence of vibration in the tool magazine can be more reliably suppressed.

[0057] Furthermore, based on the magnitude of the maximum speed of the tool magazine 7, one of a plurality of acceleration waveforms relating to the second acceleration is selected. For example, if it is determined that the maximum speed is equal to or greater than a threshold, a first waveform forming an isosceles trapezoid shape is selected, and if it is determined that the maximum speed is not equal to or greater than the threshold, a second waveform forming an isosceles triangle shape is selected. The control device 4 can calculate the travel distance during deceleration corresponding to the selected acceleration waveform, and appropriately control the speed of the tool magazine 7.

[0058] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. [Explanation of symbols]

[0059] 1 Machine tools 4. Control device 4a CPU 4b RAM 4c storage section 7 Tool Magazine 7a Magazine motor

Claims

1. A control device for a machine tool that controls the drive of a tool magazine that stores a plurality of tools and replaces a tool attached to a spindle with a tool stored in the tool magazine, comprising: an acceleration unit that accelerates the tool magazine at a first acceleration when a predetermined tool stored in the tool magazine is indexed to a replacement position after the tool is removed from the spindle; a deceleration section that decelerates the tool magazine at a second acceleration after the acceleration section has completed; Equipped with The magnitude of the maximum value of the second jerk which is a time derivative of the second acceleration is smaller than the magnitude of the maximum value of the first jerk which is a time derivative of the first acceleration. Control device.

2. The magnitude of the maximum value of the second acceleration is smaller than the magnitude of the maximum value of the first acceleration. The control device according to claim 1 .

3. A selection unit is provided for selecting one of a plurality of acceleration waveforms relating to the second acceleration based on the magnitude of the maximum speed of the tool magazine. The control device according to claim 1 or 2.

4. the plurality of acceleration waveforms include a first waveform having a period in which acceleration is constant and a second waveform having no period in which acceleration is constant; a determination unit that determines whether the maximum speed is equal to or greater than a threshold determined by a maximum value of the second acceleration, The selection unit selects a first waveform when the determination unit determines that the maximum speed is equal to or greater than the threshold, and selects a second waveform when the determination unit determines that the maximum speed is not equal to or greater than the threshold. The control device according to claim 3.

5. A calculation unit is provided for calculating the threshold value based on a maximum acceleration and a maximum jerk during deceleration of the tool magazine. The control device according to claim 4.

6. A setting unit is provided for setting a maximum acceleration and a maximum jerk during deceleration of the tool magazine. The control device according to claim 5.

7. A method for controlling a machine tool in which a tool magazine storing a plurality of tools is controlled and a tool attached to a spindle is replaced with a tool stored in the tool magazine, comprising the steps of: When a predetermined tool stored in the tool magazine is indexed to a replacement position after the tool is removed from the spindle, the tool magazine is accelerated at a first acceleration; After the acceleration is completed, the tool magazine is decelerated at a second acceleration rate. The magnitude of the maximum value of the second jerk which is the time derivative of the second acceleration is smaller than the magnitude of the maximum value of the first jerk which is the time derivative of the first acceleration. Control methods.

8. A computer program executable by a machine tool control device that controls the drive of a tool magazine that stores a plurality of tools and replaces a tool attached to a spindle with a tool stored in the tool magazine, comprising: The control device includes: When a predetermined tool stored in the tool magazine is indexed to a replacement position after the tool is removed from the spindle, the tool magazine is accelerated at a first acceleration; After the acceleration is completed, the tool magazine is decelerated at a second acceleration rate. Execute the process, The magnitude of the maximum value of the second jerk which is the time derivative of the second acceleration is smaller than the magnitude of the maximum value of the first jerk which is the time derivative of the first acceleration. Computer program.

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