JP2002205236A - Method and device for controlling tool exchanging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide method and device for controlling a tool changing device allowing an optimal tool changing time in response with tool weight. SOLUTION: This control device comprises a parameter storing part 14 for storing data related to rotation speed, time constant, position loop gain, and speed loop gain, and a drive control part 13 for sequentially generating an operation command signal, a speed command signal, and a current command signal based on the rotation speed or the like stored in the parameter storing part 14 and controlling a servo motor 5 for driving an exchanging arm 2. The control device comprises a data storing part 16 for storing the rotation speed, time constant, and speed loop gain set in response with the tool weight, and a parameter rewriting part 15 for referring to the data storing part 16 based on the tool weight, extracting the rotation speed, time constant, and speed loop gain corresponding to the referring result, and rewriting the data stored in the parameter storing part 14. The servo motor 5 is controlled based on the rotation speed, time constant, and speed loop gain rewritten in response with the tool weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and a control device for controlling the operation of a tool changer for exchanging a tool mounted on a main shaft of a machine tool with another tool. The present invention relates to a control method and a control device for controlling the operation of a servo motor as a driving unit.

[0002]

2. Description of the Related Art In general, a tool changer applied to a machine tool includes an exchange arm for holding a tool, a rotary shaft connected orthogonally to the exchange arm, and an axial movement of the rotary shaft. And a drive means for rotating about the axis, and the replacement arm is attached to the main shaft by performing a combined operation of movement in the direction along the axis of the rotation axis and turning movement about the rotation axis. The replaced tool is replaced with a tool arranged at an appropriate position. An electric motor (drive motor) has been used for at least rotation of the rotating shaft.

[0003] In the field of machine tools, the operation time of each operating section has been reduced in order to reduce the processing time and the processing cost. The tool changer is no exception, and the operation time of the change arm is being shortened. In the case of frequent tool change,
The tool change time accounts for a large percentage of the total machining time,
Shortening is an important issue.

Against this background, a method disclosed in Japanese Patent Application Laid-Open No. 3-60941 has been proposed as a method for optimizing the rotation operation of the exchange arm. This Japanese Patent Application Laid-open No. Hei 3-6
In the tool changing method disclosed in Japanese Patent Application Publication No. 0941, first, a weight moment is calculated based on the dimensions of the tool, and a speed rank (high speed, medium speed, low speed) related to the rotation speed of the changing arm is calculated based on the calculated weight moment. ) Is stored in the tool data storage unit for each tool, and in actual tool change, a speed rank corresponding to the tool gripped by the replacement arm is read from the tool data storage unit, and the obtained speed is determined. The replacement arm is rotated at a rotation speed according to the rank.

[0005]

However, according to the tool changing method disclosed in Japanese Patent Application Laid-Open No. 3-60941, the tool changing method is tentative in that the rotation speed of the changing arm is optimized according to the tool weight. Although it is possible to reduce the time, it has not been enough.

That is, when the drive motor rotates, the drive motor is accelerated at an acceleration according to a predetermined time constant.
When the motor reaches the set rotation speed (constant speed) and stops, the motor is decelerated at an acceleration according to the time constant and then stopped. Therefore, in order to further reduce the tool change time, it is necessary to optimize the acceleration during acceleration / deceleration in accordance with the tool weight.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a control method and a control device for a tool changing device which can optimize a tool changing time according to a tool weight. And

[0008]

Means for Solving the Problems and Effects There is provided a tool changing apparatus for replacing a tool mounted on a main shaft of a machine tool with another tool according to the first aspect of the present invention. With an exchange arm that grips the tool,
A method for driving and controlling the servo motor of a tool changing device provided to change a tool by turning the change arm by a drive system including a servo motor,
An operation command signal is generated based on a preset rotation speed and time constant, and a speed command signal is obtained by multiplying a deviation between the generated operation command signal and a current position signal fed back from the drive system by a position loop gain. After generating a current command signal by multiplying a deviation between the obtained speed command signal and a current speed signal fed back from the driving system by a speed loop gain, the driving is performed based on the obtained current command signal. In a control method for driving and controlling a servomotor of a system, a weight of a tool gripped by the exchange arm is recognized, and a rotation speed, a time constant, and a speed loop gain set in advance according to the tool weight are selected. A rotation speed, a time constant and a speed loop gain are selected according to the recognized tool weight. Command signal, sequentially generates the speed command signal and a current signal driving the servo motor, according to the method of controlling the tool changer, characterized by control.

This control method can be suitably implemented by the device invention described in claim 2. That is, the invention described in claim 2 is a tool changing device for changing a tool mounted on a main shaft of a machine tool with another tool, comprising a changing arm for holding a tool, and a driving system including a servomotor. An apparatus for driving and controlling the servomotor of a tool changer provided to change a tool by turning an exchange arm, wherein a preset rotation speed, time constant, position loop gain, and speed loop gain are set. A parameter storage unit storing data relating to
An operation command signal is generated based on the rotation speed and the time constant stored in the parameter storage unit, and a deviation between the generated operation command signal and a current position signal fed back from the drive system is stored in the parameter storage unit. A speed command signal is generated by multiplying the obtained position loop gain, and a deviation between the obtained speed command signal and a current speed signal fed back from the drive system is multiplied by a speed loop gain stored in the parameter storage unit. And a drive control unit for driving and controlling the servomotor of the drive system based on the obtained current command signal, the rotation speed being set in accordance with the tool weight. , A data storage unit storing a time constant and a speed loop gain,
Recognizing the weight of the tool gripped by the exchange arm, searching data stored in the data storage unit, and extracting a rotation speed, a time constant, and a speed loop gain according to the recognized tool weight, A parameter rewriting unit for rewriting data stored in the parameter storage unit with the extracted rotation speed, time constant, and speed loop gain, wherein the drive control unit rewrites the data according to the tool weight by the parameter rewriting unit; The tool change is performed by sequentially generating the operation command signal, the speed command signal, and the current command signal based on the determined rotation speed, time constant, and speed loop gain to drive and control the servomotor. The present invention relates to a device control device.

According to the control method and the control device, first, the parameter rewriting processing unit recognizes the weight of the tool gripped by the replacement arm when the tool is replaced, and stores the weight in the data storage unit based on the recognized tool weight. The retrieved data is retrieved, and the rotation speed, time constant, and speed loop gain corresponding to the tool weight are extracted, and the data stored in the parameter storage unit is extracted using the extracted rotation speed, time constant, and speed loop gain. Rewritten. Next, an operation command signal, a speed command signal, and a current command signal are sequentially generated by the drive control unit based on the rewritten rotation speed, time constant, and speed loop gain, and the servomotor is driven and controlled.

As described above, in the present invention, the rotation of the exchange arm is controlled by the rotation speed, the time constant, and the speed loop gain that are optimally set according to the weight of the tool held by the exchange arm. That is, the rotation of the exchange arm is set such that the acceleration is increased and the rotation speed in the constant speed state is increased as the tool becomes lighter, while the rotation speed in the constant speed state is decreased as the tool becomes heavier. Is controlled. Therefore, in the case of a small-weight tool, the rotation is started up quickly and at a high speed, and in the case of a heavy-weight tool, the rotation is started up slowly and the rotation is made at a low speed. As a result, it is possible to shorten the tool change time, and it is possible to optimize the time.

The tool weight recognition processing in the parameter rewriting processing section can be executed by the invention according to claim 3. That is, the invention according to claim 3 includes a storage unit that stores a tool weight in association with a tool number, and the parameter rewriting processing unit stores the storage unit based on a tool number instructed at the time of tool replacement. The search is configured to recognize the weight of the tool held by the exchange arm.

Further, the recognition processing can be executed by the invention described in claim 4. That is, the invention according to claim 4 includes a storage unit that stores a tool exchange code set for each tool weight and the tool weight in association with each other, and the parameter rewriting processing unit is instructed when a tool is exchanged. The weight of a tool held by the change arm is recognized by searching the storage unit based on the tool change code.

[0015] The extraction processing of the rotation speed, the time constant, and the speed loop gain according to the tool weight in the parameter rewriting processing section is also performed by the invention according to claim 5.
You can do this. That is, in the invention described in claim 5, the data storage unit associates the tool exchange code set for each tool weight with the rotation speed, the time constant, and the speed loop gain set according to the tool weight. And the parameter rewriting processing unit:
The data storage unit is searched based on the tool exchange code instructed at the time of tool exchange, and a rotation speed, a time constant, and a speed loop gain corresponding to the tool exchange code are extracted, and the extracted rotation speed, The drive control unit is configured to rewrite data stored in the parameter storage unit with a time constant and a speed loop gain. The operation command signal, the speed command signal, and the current command signal are sequentially generated based on a constant and a speed loop gain to drive and control the servo motor.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a schematic configuration of a tool changing device and a control device thereof according to the present embodiment.

As shown in FIG. 1, the tool changer 1 of this embodiment
Is an exchange arm 2 for holding a tool, and the exchange arm 2
A driving mechanism 4 for moving the rotating shaft 3 in the axial direction and rotating about the axis, a servomotor 5 for applying power to the driving mechanism 4, and the like. . The exchange arm 2 is provided with gripping portions 2a, 2 for gripping a tool.
a is provided at both ends thereof, and the combined operation of the movement in the direction along the axial direction of the rotating shaft 3 and the turning movement around the rotating shaft 3 by the operation of the servomotor 5 and the driving mechanism unit 4 The tool mounted on the main shaft and the tool arranged at an appropriate position are held by the holding portions 2a, 2a, and are exchanged. Incidentally, the servo motor 5 is provided with a position detector for detecting the rotational position of the output shaft.

On the other hand, the control device 10 comprises a program storage unit 11, a program analysis unit 12, a drive control unit 13, a parameter storage unit 14, a parameter rewrite processing unit 15, a data storage unit 16, and the like. Note that the control device 10 of the present example
It constitutes a numerical control device of a machine tool, and FIG. 1 shows only those parts necessary for the description of the present embodiment.

The program storage section 11 is a functional section for storing a machining program created in advance, and the program analysis section 12 analyzes the machining program stored in the program storage section 11 to change tools in the machining program, to change the spindle. A command relating to the feed speed and the moving position of the rotation and feed drive system is extracted, and the extracted command relating to tool exchange is transmitted to the drive control unit 13 and the parameter rewriting processing unit 15.

The parameter storage section 14 is a function section for storing data such as a rotation speed, a time constant, a position loop gain, and a speed loop gain necessary for controlling the servo motor 5, and the drive control section 13 stores parameter data. Part 1
An operation command signal is generated based on the rotation speed and the time constant stored in the parameter storage unit 4, and a deviation between the generated operation command signal and a current position signal fed back from the servo motor 5 is stored in the parameter storage unit 14. A velocity command signal is generated by multiplying the velocity loop signal stored in the parameter storage unit 14 by a deviation between the obtained velocity command signal and the current velocity signal fed back from the servo motor 5. After the current command signal is generated by multiplication, the obtained current command signal is transmitted to the servo motor 5 to control its operation.

The data storage unit 16 is a functional unit that stores the tool number and weight of each tool in association with each other, and stores a rotation speed, a time constant, and a speed loop gain set according to the tool weight. Yes, specifically, the data shown in FIGS. 4 and 5 is stored.

The parameter rewriting section 15 recognizes the weight of the tool held by the change arm 2 at the time of tool change based on the signal transmitted from the program analysis section 12 and calculates the recognized tool weight. Based on the data storage unit 1
6 is retrieved to extract a rotation speed, a time constant, and a speed loop gain according to the tool weight. The extracted rotation speed, time constant, and speed loop gain are stored in the parameter storage unit 14. This is a processing unit for rewriting the stored data, and specifically executes the processing shown in FIGS.

Hereinafter, the operation of the tool changer 1 and the specific processing in the controller 10 will be described focusing on the processing shown in FIG. 2 and FIG.

First, as described above, in the program analysis section 12, the machining program stored in the program storage section 11 is analyzed, and when a command relating to tool exchange is extracted from the machining program, the program analysis section 12 relates to the extracted tool exchange. The command is the drive control unit 13 and the parameter rewriting processing unit 1
5 is sent.

As shown in FIG. 2, the parameter rewriting processing unit 15 confirms a tool change command transmitted from the program analysis unit 12 (step S1), and upon receiving the tool change command, mounts a tool on the spindle. It is determined whether or not it has been performed (step S2). Note that, in addition to the tool change command, the tool number of the next tool for tool change specified in the machining program is transmitted from the program analysis unit 12 to the parameter rewrite processing unit 15. The unit 15 temporarily stores the tool number of the next tool. Therefore, the parameter rewriting processing unit 1
5 confirms the tool number stored at the time of the previous tool change, so that it is possible to recognize whether or not a tool is mounted on the spindle, and if so, the tool number.

In step S2, it is confirmed that a tool is mounted on the spindle, and when the tool number is recognized, the parameter rewriting processing unit 15 then stores the data based on the recognized tool number. The data table of FIG. 4 stored in the unit 16 is searched, and the weight data Y of the tool mounted on the spindle is read (step S3). On the other hand, when the tool of the spindle is not mounted, the weight data Y is set to 0 (step S4).

Next, the parameter rewriting processing section 15 determines whether or not the tool number of the next tool has been transmitted from the program analysis section 12 (step S5), and if so, based on the received tool number. Then, similarly to the above, the data table of FIG. 4 stored in the data storage unit 16 is searched to read the weight data X of the next tool (replacement tool) (step S6). On the other hand, if the tool number has not been received, the weight data X of the next tool is set to 0 (step S).
7).

Next, the parameter rewriting processing section 15 adds up the weight data Y of the tool mounted on the main spindle and the weight data X of the next tool to obtain the total weight Z of the tool held by the replacement arm 2. Is calculated (step S8), and the calculated total weight Z is calculated.
Is determined whether Z ≦ 5Kg, 5Kg <Z ≦ 10Kg, or 10Kg <Z (step S).
9) Based on the calculated total weight Z, the data table of FIG.
(Rotational speed, time constant, speed loop gain) corresponding to the parameter (steps S10 to S12), and rewrite the data stored in the parameter storage unit 14 with the read rotational speed, time constant, and speed loop gain (steps S10 to S12). Steps S13 to S15). Each data in the data table shown in FIG. 5 is A1 <B1 <C1, C2 <B2 <A
2, C3 <B3 <A3.

Thereafter, the processing is continued until a processing end signal is received from the program analysis unit 12 (step S1).
6).

The drive control unit 13 operates as described above.
Using the rotation speed, time constant, and speed loop gain stored in the parameter storage unit 14 rewritten according to the tool weight and a predetermined position loop gain stored in the parameter storage unit 14, an operation command signal, a speed command signal, A current command signal is sequentially generated, and the generated current signal is
Send to

The servo motor 5 is driven by a current signal generated according to the tool weight, and drives the exchange arm 2 via the drive mechanism 4. The exchange arm 2 has a rotating shaft 3
Performs a combined operation of the movement in the direction along the axial direction and the turning movement about the rotation axis 3, whereby the tool mounted on the main shaft and the next tool arranged at a predetermined position are exchanged. .

As described above, according to the tool changing device 1 and the control device 10 of the present embodiment, the rotation speed, the time constant, and the speed loop gain optimally set according to the weight of the tool gripped by the changing arm 2. Thus, the rotation of the exchange arm 2 is controlled. Specifically, the replacement is performed such that the lower the weight of the tool, the higher the acceleration and the rotation speed in the constant speed state, and the higher the weight of the tool, the lower the acceleration and the rotation speed in the constant speed state. The rotation of the arm 2 is controlled. Therefore,
In the case of a tool with a small weight, the rotation is launched quickly,
In addition, the tool is rotated at a high speed, and in the case of a heavy tool, the rotation is slowly started and the tool is rotated at a low speed. As a result, the tool change time can be shortened, and this can be optimized.

As described above, one embodiment of the present invention has been described. However, specific embodiments that can be adopted by the present invention are not limited thereto. For example, the data storage unit 16
However, the data shown in FIG. 7 may be stored, and the parameter rewriting processing unit 15 may be configured to execute the processing shown in FIG.

The data shown in FIG. 7 includes the 100s of M codes, which are command codes for tool exchange, and the tool weights corresponding to each M code (total weight of tools held by the exchange arm).
And a time constant, a rotation speed, and a speed loop gain according to the tool weight are associated with each other. The numerical value of the M code is set in advance according to the tool weight, and the programmer who creates the machining program specifies the corresponding M code in the machining program based on the weight of the tool to be replaced. .

The parameter rewriting processing unit 15 determines whether a tool change command based on an M code has been transmitted from the program analysis unit 12 (step S21). After confirmation (step S22), the data table of FIG. 7 stored in the data storage unit 16 is searched based on the confirmed M code, and parameters (rotation speed, time constant, speed loop gain) corresponding to the M code are searched. ) Is read (step S23), and the data stored in the parameter storage unit 14 is rewritten with the read rotation speed, time constant, and speed loop gain (step S24). Thereafter, a machining end signal is received from the program analysis unit 12. Until the processing is continued (step S
25). Even in this case, the same effects as those of the above embodiment can be obtained.

Further, the data storage unit 16 stores two data: a data table in which M codes and tool weights are associated with each other, and a data table in which tool weights, rotational speeds, time constants, and speed loop gains are mutually associated. The table is stored, and the parameter rewriting processing unit 15 first recognizes the tool weight from the M code, and then, based on the recognized tool weight, calculates a rotation speed, a time constant, and a speed loop gain according to the recognized tool weight. Acquired and stored in the parameter storage unit 1
4 may be configured to rewrite the data stored therein.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a tool changing device and a control device thereof according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure in a parameter rewriting processing unit according to the embodiment.

FIG. 3 is a flowchart showing a processing procedure in a parameter rewriting processing unit according to the embodiment.

FIG. 4 is a data table showing data stored in a data storage unit according to the embodiment.

FIG. 5 is a data table showing data stored in a data storage unit according to the embodiment.

FIG. 6 is a flowchart showing a processing procedure in a parameter rewriting processing unit according to another embodiment of the present invention.

FIG. 7 is a data table showing data stored in a data storage unit according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tool changer 2 changer arm 3 rotation axis 4 drive mechanism 5 servomotor 10 controller 11 program storage 12 program analyzer 13 drive controller 14 parameter storage 15 parameter rewrite processor 16 data storage

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuya Yamamoto 106 Kitayamayamacho, Yamatokoriyama-shi, Nara Prefecture F-term in Mori Seiki Seisakusho (reference) 3C002 FF03 HH01 HH06

Claims (5)

[Claims] 1. A tool changer for exchanging a tool mounted on a main shaft of a machine tool with another tool, comprising an exchange arm for gripping a tool, and rotating the exchange arm by a drive system including a servomotor. A method for driving and controlling the servomotor of a tool changer provided to change tools by operating the generated command signal based on a preset rotation speed and a time constant. A speed command signal is generated by multiplying a deviation between the command signal and the current position signal fed back from the drive system by a position loop gain, and then a difference between the obtained speed command signal and the current speed signal fed back from the drive system is obtained. After a current command signal is generated by multiplying the deviation by a speed loop gain, a control method for driving and controlling the servomotor of the drive system based on the obtained current command signal is used. And recognizing the weight of the tool gripped by the exchange arm, and among the rotation speed, time constant and speed loop gain preset according to the tool weight, the rotation speed according to the recognized tool weight, A time constant and a speed loop gain are selected, and the operation command signal, the speed command signal, and the current command signal are sequentially generated based on the selected rotation speed, time constant, and speed loop gain to drive and control the servomotor. A method for controlling a tool changing device. 2. A tool exchanging device for exchanging a tool mounted on a main shaft of a machine tool for another tool, comprising an exchanging arm for gripping the tool, and rotating the exchanging arm by a drive system including a servomotor. A device for driving and controlling the servo motor of a tool changing device provided to change tools by using a parameter storing data on a preset rotation speed, time constant, position loop gain and speed loop gain. A storage unit, an operation command signal is generated based on the rotation speed and the time constant stored in the parameter storage unit, and a deviation between the generated operation command signal and a current position signal fed back from the drive system is used as the parameter. A speed command signal is generated by multiplying by the position loop gain stored in the storage unit, and then the obtained speed command signal is fed back from the drive system. A current command signal is generated by multiplying a deviation from the current speed signal by a speed loop gain stored in the parameter storage unit, and the servomotor of the drive system is driven and controlled based on the obtained current command signal. A data storage unit storing a rotation speed, a time constant, and a speed loop gain set according to the tool weight, and recognizing a weight of the tool held by the exchange arm. And searching the data stored in the data storage unit to extract a rotation speed, a time constant, and a speed loop gain according to the recognized tool weight, and using the extracted rotation speed, time constant, and speed loop gain. A parameter rewriting processing unit that rewrites data stored in the parameter storage unit, wherein the drive control unit controls the parameter rewriting processing unit according to a tool weight. The operation command signal, the speed command signal, and the current command signal are sequentially generated based on the rewritten rotation speed, time constant, and speed loop gain to drive and control the servo motor. Tool changer control device. 3. A storage unit for storing a tool weight in association with a tool number, wherein the parameter rewriting processing unit searches the storage unit based on a tool number instructed at the time of tool replacement,
3. The control device for a tool changing device according to claim 2, wherein the control device is configured to recognize a weight of the tool held by the changing arm. 4. A storage unit for storing a tool change code set for each tool weight in association with the tool weight, wherein the parameter rewriting processing unit stores the tool change code instructed at the time of tool change. 3. The control device for a tool changer according to claim 2, wherein the weight of the tool held by the change arm is recognized by searching the storage unit based on the search result. 5. The data storage unit stores a tool exchange code set for each tool weight, and a rotation speed, a time constant, and a speed loop gain set according to the tool weight in association with each other. The parameter rewriting processing unit searches the data storage unit based on the tool change code instructed at the time of tool change, and extracts a rotation speed, a time constant, and a speed loop gain corresponding to the tool change code. The data stored in the parameter storage unit is rewritten with the extracted rotation speed, time constant, and speed loop gain, and the drive control unit is configured to execute the parameter rewriting processing unit according to a tool change code. The operation command signal, the speed command signal, and the current command signal are sequentially generated based on the rewritten rotation speed, time constant, and speed loop gain, and Driving Bomota control device of the tool changer of the constructed comprising according to claim 2 to control.