JP7655229B2 - Control device, control method, and computer program - Google Patents

Description

This technology relates to a control device, a control method, and a computer program for controlling a machine tool.

Conventionally, machine tools are equipped with a spindle head that can move up and down, and a tool magazine (see, for example, Patent Document 1). The tool magazine is equipped with multiple movable bodies connected in an endless manner. Each movable body holds multiple gripping arms (pots) that hold tools. The tool magazine moves the multiple movable bodies along a rail that surrounds the spindle head, and positions a specified pot below the spindle head (index position). The spindle head descends and attaches the tool held by the pot to the spindle. In the machine tool described in Patent Document 1, the pots are arranged at equal intervals on the rail, so that movement control for replacing the pots arranged at the index position is possible based on information on the length of one revolution of the rail and the total number of pots.

JP 2013-154436 A

However, in order to increase the number of pots in a tool magazine in a machine tool, it is possible to arrange the pots at unequal intervals. In this case, the drive amount during movement control cannot be calculated using the same process as above.

This disclosure has been made in consideration of these circumstances, and aims to provide a control device etc. that is capable of controlling movement for replacing pots placed at index positions, even in machine tools where pots are placed at uneven intervals.

A control device according to one embodiment of the present disclosure is a control device for a machine tool having a spindle, an endless rail, and a tool magazine having a plurality of pots arranged at unequal intervals on the rail and storing tools, the plurality of pots including a current pot arranged at an index position for mounting on the spindle and a planned pot to be arranged at the index position, and the control device is provided with an acquisition unit that acquires the distance between the plurality of pots, a calculation unit that calculates a movement amount based on information on the current pot and the planned pot and the distance, and a control unit that controls the movement of the pot along the rail based on the movement amount in order to arrange the planned pot at the index position.

The control device according to one embodiment of the present disclosure enables movement control for replacing pots placed at index positions in a machine tool in which pots are placed at uneven intervals.

In a control device according to an embodiment of the present disclosure, the intervals include a first interval and a second interval wider than the first interval, the pots are arranged so that the first intervals and the second intervals alternate, and the calculation unit calculates the amount of movement based on a first distance, which is the distance of the first interval, and a second distance, which is the distance of the second interval.

According to a control device according to an embodiment of the present disclosure, in a machine tool in which two types of spacing are arranged alternately, movement control for replacing pots placed at index positions is possible.

In a control device according to an embodiment of the present disclosure, the information includes a number assigned to the pot and a starting interval indicating the distance between the current pot and the adjacent pot upstream in the movement direction, and the calculation unit calculates the number of pots to be moved based on the numbers assigned to the current pot and the planned pot, and calculates the movement amount by adding the product of the sum of the first distance and the second distance and the quotient obtained by dividing the number of pots to be moved by 2 to the product of the distance of the starting interval and the remainder obtained by dividing the number of pots to be moved by 2.

According to a control device according to an embodiment of the present disclosure, it is possible to calculate the amount of movement regardless of the distance between the pot and the adjacent pot in the direction of movement.

The control device according to one embodiment of the present disclosure includes a memory unit that stores the first distance and the second distance, and the acquisition unit acquires the first distance and the second distance from the memory unit.

According to a control device according to an embodiment of the present disclosure, it is possible to calculate the amount of movement based on the first distance and the second distance.

A control device according to an embodiment of the present disclosure includes a memory unit that stores the distance around the rail, the total number of pots, and the ratio of the first interval to the second interval, and the acquisition unit acquires the first distance and the second distance based on the distance around the rail, the total number of pots, and the ratio of the first interval to the second interval.

According to a control device according to an embodiment of the present disclosure, even if the configuration of the machine tool is changed, it is possible to calculate the first distance and the second distance by re-storing the changed numerical values.

In one embodiment of the present disclosure, the control device includes a memory unit in which the information includes the coordinates of the current pot and the planned pot, and stores coordinates corresponding to the coordinates assigned to the pots, and the acquisition unit acquires the coordinates of the current pot and the planned pot from the memory unit, calculates the difference between the coordinates of the current pot and the planned pot from the memory unit, and acquires the distance based on the difference.

The control device according to one embodiment of the present disclosure makes it possible to control movement for replacing pots placed at index positions in a machine tool in which pots are arranged at irregular intervals.

The control device according to one embodiment of the present disclosure includes a movement direction determination unit that determines the direction in which to move the pot based on the coordinates assigned to the current pot and the planned pot, and the calculation unit calculates the amount of movement based on the movement direction.

According to a control device according to an embodiment of the present disclosure, when replacing a pot placed at an index position, movement control is possible in a movement direction that results in a shorter movement amount.

A control method according to one embodiment of the present disclosure is a control method for a machine tool having a spindle, an endless rail, and a tool magazine having a plurality of pots arranged at unequal intervals on the rail for storing tools, the plurality of pots including a current pot to be attached to the spindle and a planned pot to be placed at the index position, the control method obtains distances between the plurality of pots, calculates a movement amount based on information on the current pot and the planned pot and the distance of the interval, and moves the pot along the rail based on the movement amount to place the planned pot at the index position.

According to a control method according to an embodiment of the present disclosure, in a machine tool in which pots are arranged at uneven intervals, movement control for replacing pots to be placed at index positions is possible.

A computer program according to one embodiment of the present disclosure is a program executable by a control device of a machine tool having a spindle, an endless rail, and a tool magazine having a plurality of pots arranged at unequal intervals on the rail for storing tools, the plurality of pots including a current pot to be attached to the spindle and a planned pot to be arranged at the index position, and causes the control device to execute a process of acquiring distances between the plurality of pots, calculating a movement amount based on information relating to the current pot and the planned pot and the distance of the interval, and moving the pot along the rail based on the movement amount in order to arrange the pot at the index position.

According to a computer program according to an embodiment of the present disclosure, in a machine tool in which pots are arranged at uneven intervals, movement control for replacing pots to be placed at index positions is possible.

The control device according to one embodiment of the present disclosure is capable of controlling movement to replace pots placed at index positions, even in machine tools where pots are placed at uneven intervals.

FIG. FIG. FIG. 2 is a right side view of the machine tool with the chain portion and other parts omitted. FIG. FIG. 4 is a schematic perspective view of a tool magazine that moves along a rail portion. FIG. 2 is a simplified partially enlarged plan view of the machine tool; FIG. 2 is a block diagram showing a control device. FIG. 2 is a schematic top view of the rail and the pot. 11 is a flowchart illustrating a method for determining a moving direction and a method for calculating the number of pots to be moved. 4 is a flowchart illustrating a drive control according to the first embodiment. 11 is a flowchart illustrating a first distance and a second distance calculation process. FIG. 11 is a schematic top view of a rail and a pot according to a third embodiment. 13 is a flowchart illustrating a method for setting a start point distance and an end point distance according to a third embodiment. 13 is a flowchart illustrating a method for setting a start point distance and an end point distance according to a third embodiment. 10 is a flowchart illustrating a drive control according to a third embodiment. FIG. 11 is a schematic top view of a rail and a pot according to a fourth embodiment. FIG. 13 is an explanatory diagram showing a coordinate table. 10 is a flowchart illustrating a drive control according to a fourth embodiment.

(Embodiment 1)
A machine tool and a control device according to a first embodiment will be described below with reference to the drawings. In the following description, up, down, front, back, left and right are used as shown in the drawings.

Figure 1 is a perspective view of the machine tool. Figure 2 is a front view of the machine tool. Figure 3 is a right side view of the machine tool with the chain section and the like omitted. The machine tool 100 includes a base 10, a spindle head 20, a tool magazine 30, and the like. The base 10 is rectangular and extends in the front-to-rear direction. The workpiece holding section 11 is provided on the upper front side of the base 10. The workpiece holding section 11 holds the workpiece to be machined. The workpiece holding section 11 can rotate around the C-axis extending up and down. The support table 12 is provided on the rear side of the upper part of the base 10. An X-axis direction moving device 14 is provided on the upper surface of the support table 12. The X-axis direction moving device 14 can move in the left-right direction (X-axis direction). The Y-axis direction moving device 15 is provided on the upper part of the X-axis direction moving device 14. The Y-axis direction moving device 15 supports the column 13 so that it can move in the front-to-rear direction (Y-axis direction). The Z-axis direction moving device 16 is provided on the front side of the column 13. The Z-axis direction moving device 16 moves the spindle head 20 in the vertical direction (Z-axis direction).

The spindle head 20 is equipped with a spindle 21 that extends vertically. The spindle 21 rotates around its axis. A tool is attached to the lower end of the spindle 21. A spindle motor 22 is provided at the upper end of the spindle head 20. The spindle 21 and the tool rotate with the rotation of the spindle motor 22. The rotating tool machines the workpiece held by the workpiece holding unit 11.

Figure 4 is a schematic perspective view of the rail section. Figure 5 is a schematic perspective view of the tool magazine moving on the rail section. The tool magazine 30 includes a rail section 31, a chain section 32, and a magazine drive section 33. The tool magazine 30 moves the chain section 32 along the rail section 31 by driving the magazine drive section 33. The rail section 31 includes two support beams 311, a rail base 312, and a rail 313. The support beam 311 is a plate-shaped structural member in the shape of a right triangle. The hypotenuse of the support beam 311 is disposed on the upper side. The hypotenuse of the support beam 311 inclines downward as it approaches the front. The support beam 311 is fixed to the left and right of the column 13 in a cantilever manner. The support beam 311 extends from the portion fixed to the left and right of the column 13 to both side portions of the spindle head 20. The upper end surface of the support beam 311 inclines from the lower front to the upper rear at approximately 30 degrees from the horizontal plane.

The rail base 312 is a rounded rectangular shape in plan view, and extends forward and backward. The rail base 312 is fixed to the hypotenuse of the support beam 311, and surrounds the column 13 and the spindle 21. The rail base 312 is inclined at approximately 30 degrees from the horizontal plane. A positioning mechanism 314 that aligns the positions of the tool and the spindle 21 is provided in the center of the front lower end of the rail base 312. The center of the lower end of the rail base 312 is located at the tool replacement position.

The rail 313 is provided on the upper part of the rail base 312 and forms an endless track. The rail 313 is a rectangle with rounded corners in a plan view and has a substantially rectangular cross section. The rail 313 has two first straight portions 313a facing each other and two second straight portions 313b facing each other, and the ends of the first straight portions 313a and the second straight portions 313b are connected by a curved portion 313c. The two first straight portions 313a are provided at the front and rear of the spindle head 20, respectively, and extend linearly in the left-right direction. The two second straight portions 313b are provided at the left and right of the spindle head 20, respectively, and extend linearly in the front-rear direction, i.e., in a direction perpendicular to the left-right direction. The rail base 312 and the rail 313 are arranged such that the first straight portions 313a are parallel to a direction perpendicular to the axial direction of the spindle 21, and the longitudinal center of the first straight portions 313a coincides with the axis of the spindle 21.

The mounting base 315 is provided on the inside rear of the rail base 312. The magazine drive unit 33 is attached to the upper side of the mounting base 315. The magazine drive unit 33 includes a motor 331 and a gear 332. The axis of the gear 332 is approximately perpendicular to the oblique side of the support beam 311. The gear 332 meshes with the chain portion 32. When the motor 331 rotates, the chain portion 32 and the multiple pots P rotate.

A chain section 32 is provided along the rail 313. The chain section 32 includes a plurality of moving bodies 34, a plurality of links 35, and a plurality of pots P. The pots P are arranged on the rail 313 at unequal intervals. The links 35 are elongated, approximately rectangular plates. In other words, the links 35 extend linearly. The links 35 connect adjacent moving bodies 34. The multiple moving bodies 34 and the links 35 form an endless chain.

Figure 6 is a simplified, partially enlarged plan view of the machine tool. A first distance LA between two pots P arranged on the moving body 34 is narrower than a second distance LB between two adjacent pots P across the link 35. The first distance LA is the distance between the centers of adjacent pots P in the direction of movement. The second distance LB is the distance between the shaft centers of the connecting shaft bodies 345 at both ends of the link 35. To avoid complication, only some of the connecting shaft bodies 345 are labeled in Figure 6.

Figure 7 is a block diagram showing the control device. The machine tool 100 is equipped with a control device 40 that controls the driving of the motor 331. The control device 40 drives the motor 331 to rotate the gear 332 and rotate the multiple pots P. The control device 40 is equipped with a CPU 41, a RAM 42, and a storage unit 43. The storage unit 43 has a rewritable storage medium such as an EEPROM, an EPROM, a hard disk, etc. The storage unit 43 stores the pot number assigned to each pot P, the distance of the first interval LA (first distance la), the distance of the second interval LB (second distance lb), and a processing program for processing the workpiece, etc. A processing program (program product) stored in a portable storage medium 43a, such as a CD-ROM and a flash memory, may be stored in the storage unit 43, or each program may be stored in the storage unit 43 from a server via a network. The CPU 41 reads the processing program into the RAM 42 and executes the processing program. The motor 331 also has an encoder 331a. The encoder 331a outputs a signal indicating the rotational position of the motor 331 to the control device 40. The control device 40 also includes motors, a spindle motor, and the like, which are included in the X-axis direction moving device, the Y-axis direction moving device, and the Z-axis direction moving device, but are not shown in the figure.

Figure 8 is a schematic top view of the rails and pots. Each pot is assigned a pot number, which is assigned counterclockwise from the top view, starting from 1, as shown in Figure 8. In this embodiment, the number of pots P (total number of pots) is described as 28. A pot assigned a pot number N is referred to as a pot PN. In addition, a pot PN with an odd pot number is also referred to as an odd pot, and a pot PN with an even pot number is also referred to as an even pot.

In this embodiment, each odd pot is lined up with an even pot with a pot number one larger via a moving body 34, and lined up with an even pot with a pot number one smaller via a link 35. The distance between odd pot 1 and an even pot with a pot number one larger is different from the distance between odd pot 1 and an even pot with a pot number one smaller. Specifically, the distance between each odd pot and an even pot with a pot number one larger is a first distance la, and the distance between each odd pot and an even pot with a pot number one smaller is a second distance lb. Note that pot P28 and pot P1 are lined up via a link, and the distance between them is the second distance lb. Distance 1a and distance 1b are different.

The pot P that is placed at the index position for mounting on the spindle is the current pot. That is, in FIG. 8, pot P1 is the current pot. The pot PN that is scheduled to be placed at the index position next to be used for workpiece machining is the planned pot. The pot number of the current pot is the current pot number, and the pot number of the planned pot is the planned pot number. Below, pot P10 is the planned pot, and control in an example in which planned pot P10 is moved to the index position is explained.

The control device 40 determines the movement direction for moving the planned pot P10 to the indexed position based on the pot numbers of the planned pot P10 and the current pot P1, and calculates the number of pots required to be moved. The clockwise direction when viewed from above is the forward direction, and the counterclockwise direction is the reverse direction. The detailed method of determining the movement direction and the method of calculating the number of pots to be moved will be described later, but in this example, the movement direction is the forward direction, and the number of pots to be moved is 9.

The CPU 41 of the control device 40 acquires from the memory unit 43 the first distance la, the second distance lb, and the starting distance, which is the distance between the current pot P1 and the adjacent pot upstream in the movement direction (starting distance). In this example, the starting distance is the distance between pot P1 and pot P2, so the starting distance is the first distance, and the starting distance is the first distance la. The method of setting the starting distance will be described later. The control device 40 divides the number of pots to be moved by 2 and calculates the quotient and the remainder. In this example, the quotient is 4 and the remainder is 1. The control device 40 calculates the product of the sum of the first distance la and the second distance lb and the quotient, and further adds the product of the starting distance and the remainder to determine the movement amount. In other words, the distance calculated by the following formula is determined as the movement amount.

The CPU 41 drives the motor 331 based on the calculated amount of movement. Specifically, the memory unit 43 stores the driving distance of the pot P per one rotation of the gear 332, and the control device 40 determines the amount of rotation of the motor 331 based on the driving distance and amount of movement of the pot P per one rotation of the gear 332, and drives the motor.

Figure 9 is a flow chart explaining a method for determining the movement direction and a method for calculating the number of moving pots, which are activated when a tool change command in a machining program is executed. In Figure 9, the variables X and Y are used for explanation. The CPU 41 acquires the current pot number and the planned pot number (S1), and determines whether the planned pot number is equal to or greater than the current pot number (S2). The CPU 41 acquires the current pot number based on the rotational position of the motor 331 output from the encoder 331a, and acquires the planned pot number from the machining program loaded into the RAM 42. If the planned pot number is equal to or greater than the current pot number (S2: YES), the CPU 41 sets X to the number obtained by subtracting the current pot number from the planned pot number (S3). If the planned pot number is less than the current pot number (S2: NO), the CPU 41 sets X to the number obtained by subtracting the current pot number from the planned pot number and adding the total number of pots (S4). The CPU 41 determines whether X is greater than the total number of pots/2 (S5), and if it is greater (S5: YES), sets Y to the number obtained by subtracting the total number of pots from X (S6). If X is equal to or less than the quotient obtained by dividing the total number of pots by 2 (S5: NO), the CPU 41 sets Y to the same value as X (S7). The CPU 41 determines whether Y is 0 or greater (S8), and if Y is 0 or greater (S8: YES), sets the movement direction to the forward direction (S9), and calculates the number of moved pots as the same value as Y (S10). If Y is less than 0 (S8: NO), the CPU 41 sets the movement direction to the reverse direction (S11), and calculates the number of moved pots as -Y (S12). After the CPU 41 calculates the number of moved pots in S10 or S12, the process ends.

By performing the above process, the CPU 41 can determine the closest movement direction to place the planned pot at the indexed position. In addition, regardless of whether the movement direction is forward or reverse, the correct number of pots to be moved can be calculated.

10 is a flowchart explaining the drive control according to the first embodiment, which is started after the execution of the flowchart in FIG. 9 is completed. The CPU 41 acquires the first distance la and the second distance lb from the memory unit 43 (S21). The CPU 41 acquires the current pot number (S22) and determines whether the current pot number is an even number (S23). If the current pot number is an even number (S23: YES), the CPU 41 determines whether the moving direction of the pot P is forward (S24). If the moving direction is forward (S24: YES), the CPU 41 sets the starting distance to the second distance (S27). If the moving direction is not forward, i.e., reverse (S24: NO), the CPU 41 sets the starting distance to the first distance (S26). If the pot number is not even, i.e., odd (S23: NO), the CPU 41 determines whether the moving direction of the pot P is forward (S25). If the moving direction is forward (S25: YES), the CPU 41 sets the starting point distance to the first distance (S26). If the moving direction is not forward, i.e., reverse (S25: NO), the CPU 41 sets the starting point distance to the second distance (S27). After setting the starting point distance in S26 or S27, the CPU 41 divides the number of pots moved by 2 to calculate the quotient and remainder (S28). The CPU 41 multiplies the quotient by the sum of the first distance and the second distance (S29), and also multiplies the starting point distance by the remainder (S30). The CPU 41 adds up the calculation results in S29 and S30 to calculate the moving amount (S31), and calculates the rotation amount of the motor based on the moving amount (S32). The CPU 41 drives the motor to rotate (S33), and ends the process.

By using the above process, it is possible to calculate the moving distance of the pot when changing tools, even when the pots are arranged on the rails at two different intervals.

(Embodiment 2)
The control device 40 according to the first embodiment includes a storage unit 43 that stores the first distance la and the second distance lb, whereas the control device 40 according to the present embodiment includes a storage unit 43 that stores the distance of one revolution of the rail 313 (total rail length), the total number of pots, and the ratio of the first interval to the second interval (first interval ratio RA:second interval ratio RB), and calculates the first distance la and the second distance lb by calculation by the CPU 41. Hereinafter, the second embodiment will be described with reference to the drawings. Among the configurations according to the second embodiment, the same reference numerals are used for the configurations similar to those of the first embodiment, and detailed description thereof will be omitted.

Figure 11 is a flowchart explaining the first distance and second distance calculation process. The CPU 41 acquires the distance of one revolution of the rail and the total number of pots from the memory unit 43 (S41), and calculates the average distance between each pot (average interval distance lm) by dividing the total length of the rail by the total number of pots (S42). The CPU 41 acquires the first interval ratio RA and the second interval ratio RB from the memory unit 43 (S43), and calculates the average of the first interval ratio RA and the second interval ratio RB (average interval ratio Rm) (S44). The CPU 41 multiplies the average interval distance lm by the first interval ratio RA and divides the average interval ratio Rm to calculate the first distance la (S45), and multiplies the average interval distance lm by the second interval ratio RB and divides the average interval ratio Rm to calculate the second distance lb (S46). That is, the average interval distance lm, average interval ratio Rm, first distance la, and second distance lb are calculated by the following formulas.

The memory unit 43 of the control device 40 in this embodiment stores the distance of one revolution of the rail 313, the total number of pots, and the ratio of the first distance to the second distance, so that if the configuration of the machine tool 100 is changed, it is possible to calculate the first distance and the second distance by re-storing the changed numerical values.

(Embodiment 3)
The pots P of the machine tool 100 according to the first embodiment are arranged so that the first interval and the second interval alternate, but the pots P of the machine tool 100 according to the present embodiment are arranged so that the first interval, the second interval, and the third interval alternate. Hereinafter, a third embodiment will be described with reference to the drawings. Among the configurations according to the third embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Figure 12 is a schematic top view of the rail and pots according to the third embodiment. In this embodiment, the total number of pots is 24. The distance between pot P1 and pot P2 is the first distance, the distance between pot P2 and pot P3 is the second distance, and the distance between pot P3 and pot P4 is the third distance. Similarly, the pots are arranged in rotation up to pot P24 with the first, second, and third distances. The distance between pot P24 and pot P1 is the third distance. As in the first embodiment, the distance of the first distance is the first distance la, the distance of the second distance is the second distance lb, and the distance of the third distance is the third distance lc. The memory unit 43 according to the third embodiment stores the first distance la, the second distance lb, and the third distance lc.

Below, we will explain the control in an example where pot P12 is the planned pot and planned pot P12 is moved to the indexed position. Note that the quotient in the following explanation represents an integer quotient in division. The control device 40 determines the movement direction and calculates the number of moved pots in the same way as in embodiment 1. In this example, the movement direction is forward and the number of moved pots is 11.

The CPU 41 of the control device 40 acquires from the memory unit 43 the first distance la, the second distance lb, the third distance lc, the starting distance, which is the distance between the current pot P1 and the adjacent pot on the upstream side in the moving direction (starting distance), and the end distance, which is the distance between the planned pot P12 and the adjacent pot on the downstream side in the moving direction (end distance). The method of setting the starting distance and the end distance will be described later, but in this example the starting distance is la and the end distance is lb.

The control device 40 divides the number of pots moved by 3 to calculate a first quotient and a first remainder. In this example, the first quotient is 3 and the first remainder is 2. The control device 40 further adds 1 to the first remainder and divides it by 2 to obtain a second quotient. In this example, the second quotient is 1. The control device 40 also divides the first remainder by 2 to obtain a third quotient. In this example, the third quotient is 1. The control device 40 adds up the product of the first quotient and the sum of the first distance la, the second distance lb, and the third distance lc, the product of the second quotient and the starting distance, and the product of the third quotient and the end distance to obtain the amount of movement. That is, in this example, the amount of movement is calculated using the following formula.

13 and 14 are flowcharts for explaining a method for setting the starting point distance and the end point distance according to the third embodiment. The CPU 41 of the control device 40 determines the moving direction and calculates the number of pots to be moved (see FIG. 9), and then sets the starting point distance and the end point distance. The CPU 41 acquires the first distance la, the second distance lb, and the third distance lc from the memory unit 43 (S51). The CPU 41 acquires the current pot number (S52) and determines whether the current pot number is a multiple of 3 (S53). If the current pot number is a multiple of 3 (S53: YES), the CPU 41 determines whether the moving direction of the pot P is forward (S54). If the moving direction is forward (S54: YES), the CPU 41 sets the starting point distance to the third distance (S58). If the moving direction is not forward, i.e., reverse (S54: NO), the CPU 41 sets the starting point distance to the second distance (S60). If the current pot number is not a multiple of 3 (S53: NO), the CPU 41 determines whether the remainder obtained by dividing the current pot number by 3 is 1 (S55). If the remainder is 1 (S55: YES), the CPU 41 determines whether the moving direction of the pot P is forward (S56). If the moving direction is forward (S56: YES), the CPU 41 sets the starting point distance to the first distance (S59). If the moving direction is not forward, that is, reverse (S56: NO), the CPU 41 sets the starting point distance to the third distance (S58). If the remainder obtained by dividing the current pot number by 3 is not 1, that is, the remainder is 2 (S55: NO), the CPU 41 determines whether the moving direction is forward (S57). If the moving direction is forward (S57: YES), the CPU 41 sets the starting point distance to the second distance (S60). If the movement direction is not forward, i.e., reverse (S57: NO), the CPU 41 sets the starting distance to the first distance (S59).

After setting the starting distance in S58, S59 or S60, the CPU 41 of the control device 40 acquires the scheduled pot number (S61) and determines whether the scheduled pot number is a multiple of 3 (S62). If the scheduled pot number is a multiple of 3 (S62: YES), the CPU 41 determines whether the moving direction of the pot P is forward (S63). If the moving direction is forward (S63: YES), the CPU 41 sets the end distance to the second distance (S67). If the moving direction is not forward, that is, reverse (S63: NO), the CPU 41 sets the end distance to the third distance (S68). If the scheduled pot number is not a multiple of 3 (S62: NO), the CPU 41 determines whether the remainder of dividing the scheduled pot number by 3 is 1 (S64). If the remainder is 1 (S64: YES), the CPU 41 determines whether the moving direction of the pot P is forward (S65). If the moving direction is forward (S65: YES), the CPU 41 sets the end point distance to the third distance (S68). If the moving direction is not forward, i.e., reverse (S65: NO), the CPU 41 sets the end point distance to the first distance (S69). If the remainder obtained by dividing the planned pot number by 3 is not 1, i.e., the remainder is 2 (S64: NO), the CPU 41 determines whether the moving direction is forward (S66). If the moving direction is forward (S66: YES), the CPU 41 sets the end point distance to the first distance (S69). If the moving direction is not forward, i.e., reverse (S66: NO), the CPU 41 sets the end point distance to the second distance (S67). After setting the end point distance in S67, S68, or S69, the CPU 41 ends the process.

15 is a flowchart for explaining the drive control according to the third embodiment, which is started after the execution of the flowcharts of FIG. 13 and FIG. 14 is completed. The CPU 41 divides the number of pots moved by 3 to calculate the first quotient and the first remainder (S71). The method for calculating the number of pots moved is the same as that of the first embodiment (see FIG. 9), so the details are omitted. The CPU 41 divides the first remainder + 1 by 2 to calculate the second quotient (S72), and divides the first remainder by 2 to calculate the third quotient (S73). The CPU 41 multiplies the first quotient by the sum of the first distance, the second distance, and the third distance (S74), multiplies the starting point distance by the second quotient (S75), and multiplies the end point distance by the third quotient (S76). The CPU 41 adds up the calculation results in S74, S75, and S76 to calculate the movement amount (S77), and calculates the rotation amount of the motor based on the movement amount (S78). The CPU 41 drives the motor to rotate (S79) and ends the process.

By using the above process, it is possible to calculate the movement distance of the pot when changing tools, even if the pots are arranged on the rails in rotation at three different intervals.

(Embodiment 4)
The pots P of the machine tool 100 according to the first embodiment are arranged so that the first intervals and the second intervals alternate, but the pots P of the machine tool 100 according to the present embodiment are arranged at irregular intervals in order to grip tools of various sizes. A fourth embodiment will be described below with reference to the drawings. Among the components according to the fourth embodiment, components similar to those of the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

Figure 16 is a schematic top view of the rail and pots according to embodiment 4. Figure 17 is an explanatory diagram showing a coordinate table. As shown in Figure 16, the pots P according to this embodiment are arranged on the rail at irregular intervals. As shown in Figure 17, the memory unit 43 of the control device 40 stores a coordinate table in which coordinates correspond to pot numbers. The coordinate value stores the distance counterclockwise from pot P1 as viewed from above. Hereinafter, the coordinates of the current pot are referred to as current coordinates, and the coordinates of the planned pot are referred to as planned coordinates.

Figure 18 is a flowchart explaining the drive control according to the fourth embodiment. The CPU 41 acquires the current pot number and the planned pot number (S81), and acquires the current coordinates and the planned coordinates from the coordinate table of the storage unit 43 based on the current pot number and the planned pot number (S82). The CPU 41 determines whether the planned coordinates are equal to or greater than the current coordinates (S83), and if the planned coordinates are equal to or greater than the current coordinates (S83: YES), the CPU 41 sets X to the number obtained by subtracting the current coordinates from the planned coordinates (S84). If the planned coordinates are less than the current coordinates (S83: NO), the CPU 41 sets X to the number obtained by subtracting the current coordinates from the planned coordinates and adding the total length of the rail (S85). The CPU 41 determines whether X is greater than the total length of the rail/2 (S86), and if it is greater (S86: YES), sets Y to the number obtained by subtracting the total length of the rail from X (S87). If X is equal to or less than the total length of the rail/2 (S86: NO), the CPU 41 sets Y to the same value as X (S88). The CPU 41 determines whether Y is 0 or greater (S89), and if Y is 0 or greater (S89: YES), sets the movement direction to the forward direction (S90) and calculates the movement amount as the same value as Y (S91). If Y is less than 0 (S89: NO), the CPU 41 sets the movement direction to the reverse direction (S92) and calculates the movement amount as -Y (S93). After calculating the movement amount in S91 or S93, the CPU 41 calculates the rotation amount of the motor 331 based on the movement amount (S94), drives the motor 331 to rotate (S95), and ends the process.

The above process makes it possible to calculate the pot movement distance when changing tools, even when the pots are arranged on the rail at irregular intervals. In this embodiment, the pot movement distance is the distance between the current pot and the planned pot. The coordinates stored in the coordinate table may be an angle with the center of the track of the rail 313 as the center of a circle, in which case the movement amount is calculated based on the angle and the total length of the rail.

The embodiments disclosed herein are illustrative in all respects and should not be considered 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 equivalents to the scope of the claims.

REFERENCE SIGNS LIST 100 Machine tool 30 Tool magazine 313 Rail 331 Motor 332 Gear 34 Moving body 35 Link 40 Control device 41 CPU
42 RAM
43 Memory section 43a Storage medium P pot

Claims (9)

The main axis and
A control device for a machine tool comprising: an endless rail; and a tool magazine including a plurality of pots arranged at unequal intervals on the rail for storing tools, the control device comprising:
the plurality of pots include a current pot arranged at an index position for mounting on the spindle, and a scheduled pot to be arranged at the index position,
An acquisition unit that acquires distances between the plurality of pots;
a calculation unit that calculates a movement amount for moving the scheduled pot to the index position based on information on the current pot and the scheduled pot and the distance;
and a control unit that controls the pot to move along the rail based on the movement amount in order to place the planned pot at the index position. the intervals include first intervals and second intervals wider than the first intervals, and the pots are arranged such that the first intervals and the second intervals alternate;
The control device according to claim 1 , wherein the calculation unit calculates the amount of movement based on a first distance that is the first interval and a second distance that is the second interval. The information includes a number assigned to the pot and a starting interval indicating an interval between the current pot and an adjacent pot on the upstream side in the moving direction,
The control device described in claim 2, wherein the calculation unit calculates the number of pots to be moved based on the numbers assigned to the current pot and the planned pot, and calculates the movement amount by adding the product of the sum of the first distance and the second distance and the quotient obtained by dividing the number of pots to be moved by 2 to the product of the distance between the starting points and the remainder obtained by dividing the number of pots to be moved by 2. A storage unit that stores the first distance and the second distance,
The control device according to claim 2 , wherein the acquisition unit acquires the first distance and the second distance from the storage unit. a storage unit that stores the distance of one circumference of the rail, the total number of the pots, and a ratio of the first interval to the second interval;
The control device according to claim 2 or 3, wherein the acquisition unit acquires the first distance and the second distance based on the distance of one revolution of the rail, the total number of the pots, and a ratio between the first interval and the second interval. The information includes coordinates of the current pot and the scheduled pot;
a storage unit that stores coordinates corresponding to the coordinates assigned to the pots;
The control device according to claim 1 , wherein the acquisition unit acquires the coordinates of the current pot and the planned pot from the memory unit, calculates a difference between the coordinates of the current pot and the planned pot from the memory unit, and acquires the distance based on the difference. a moving direction determining unit that determines a moving direction for moving the pot based on coordinates assigned to the current pot and the scheduled pot;
The control device according to claim 1 , wherein the calculation unit calculates the amount of movement based on the direction of movement. The main axis and
A method for controlling a machine tool comprising: a tool magazine including an endless rail and a plurality of pots arranged at unequal intervals on the rail for storing tools, the method comprising the steps of:
the plurality of pots include a current pot arranged at an index position for mounting on the spindle, and a scheduled pot to be arranged at the index position,
Obtaining distances between the plurality of pots;
Calculating a movement amount for moving the scheduled pot to the index position based on information on the current pot and the scheduled pot and the distance;
and moving the pot along the rail based on the movement amount to place the target pot at the index position. The main axis and
A program executable by a control device for a machine tool including a tool magazine having an endless rail and a plurality of pots arranged at unequal intervals on the rail for storing tools, the program comprising:
the plurality of pots include a current pot arranged at an index position for mounting on the spindle, and a scheduled pot to be arranged at the index position,
Obtaining distances between the plurality of pots;
Calculating a movement amount for moving the scheduled pot to the index position based on information on the current pot and the scheduled pot and the distance;
a computer program causing the control device to execute a process of moving the pot along the rail based on the movement amount to place the pot at the index position.

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