A tool, attachable to a spindle of a machine tool and capable of changing independently a rotational speed of a cutting tool from that of the spindle, provided with a cutting tool for machining a workpiece, an electric motor for driving the machining tool, a generator for generating electric power to drive the electric motor by the rotation of the spindle, a tool holding part for rotatably holding the cutting tool, a casing for holding the electric motor, the generator, the tool attachment part, and the tool holding part, and a locking part for preventing rotation of the casing by engagement with a non-rotating part of the machine tool. A tool includes an ac generator, an ac motor and a case holding the generator and motor such that the generator and the motor are arranged in the case along a center axis and a longitudinal direction of a rotatable portion of the generator. A rotation speed of an output shaft of the motor is based on a rotation speed of an input shaft of the generator and a ratio, between a number of poles of the generator and a number of poles of the motor.
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3. A tool attachable to a spindle of a machine tool comprising:
a machining tool for machining a workpiece;
an induction motor for driving said machining tool; and
an alternating current generator for generating electric power to drive said induction motor by the rotation of said spindle at a frequency in accordance with the rotational speed of said spindle, said induction motor rotating at a rotational speed in accordance with said frequency.
12. A tool holder attachable to a spindle of a machine tool for rotatably holding a machining tool for machining a workpiece, said tool holder comprising:
an induction motor for driving said machining tool; and
an alternating current generator for generating electric power to drive said induction motor by the rotation of said spindle at a frequency in accordance with the rotational speed of said spindle, said induction motor rotating at a rotational speed in accordance with said frequency.
2. A tool attachable to a spindle of a machine tool comprising:
a machining tool for machining a workpiece;
an electric motor for driving said machining tool; and
a generator for generating electric power to drive said electric motor by the rotation of said spindle;
wherein said generator and said electric motor change the rotational speed of said machining tool from the rotational speed of said spindle by a predetermined ratio determined based on a pole number of said generator and said electric motor.
11. A tool holder attachable to a spindle of a machine tool for rotatably holding a machining tool for machining a workpiece, said tool holder comprising:
an electric motor for driving said machining tool; and
a generator for generating electric power to drive said electric motor by the rotation of said spindle; wherein
said generator and said electric motor change the rotational speed of said machining tool from the rotational speed of said spindle by a predetermined ratio determined based on a pole number of said generator and said electric motor.
6. A tool attachable to a spindle of a machine tool comprising:
a machining tool for machining a workpiece;
an electric motor for driving said machining tool;
a generator for generating electric power to drive said electric motor by the rotation of said spindle;
control means for controlling a supply of electric power generated by said generator to drive and control said machining tool; and
rotation detecting means for detecting a rotational position and/or rotational speed of said electric motor; wherein:
said control means controls said electric motor based on the detected rotational position and/or the detected rotational speed.
1. A machine tool comprising:
a machine tool body provided with a spindle, a driving means for driving said spindle, and at least one control axis for changing a relative position between said spindle and a workpiece;
a control apparatus for controlling said driving means and said control axis in accordance with a machining program;
a tool attachable to said spindle and provided with a machining tool for machining a workpiece, an induction motor for driving said machining tool, and an alternating current generator for generating electric power to drive said induction motor by the rotation of said spindle at a frequency in accordance with the rotational speed of said spindle, said induction motor rotating at a rotational speed in accordance with said frequency.
8. A tool attachable to a spindle of a machine tool comprising:
a machining tool for machining a workpiece;
an electric motor for driving said machining tool;
a generator for generating electric power to drive said electric motor by the rotation of said spindle;
control means for controlling a supply of electric power generated by said generator to drive and control said machining tool;
rotation detecting means for detecting a rotational position and/or rotational speed of said electric motor; and
rotation detecting means for detecting a rotational position and/or rotational speed of said spindle; wherein
said control means controls said electric motor based on the detected rotational position and/or rotational speed of both of said spindle and said electric motor.
9. A machine tool comprising:
a machine tool body provided with a spindle, a driving means for driving said spindle, and at least one control axis for changing a relative position between said spindle and a workpiece;
a control apparatus for controlling said driving means and said control axis in accordance with a machining program; and
a tool attachable to said spindle and provided with a machining tool for machining a workpiece, an electric motor for driving said machining tool, and a generator for generating electric power to drive said electric motor by the rotation of said spindle; wherein
said tool changes the rotational speed of said machining tool from the rotational speed of said spindle by a predetermined ratio determined based on pole numbers of said generator and said electric motor.
13. A machine tool comprising:
a machine tool body provided with a spindle, a driving means for driving said spindle, and at least one control axis for changing a relative position between said spindle and a workpiece;
a control apparatus for controlling said driving means and said control axis in accordance with a machining program; and
a tool attachable to said spindle and provided with a machining tool for machining a workpiece, an electric motor for driving said machining tool, and a generator for generating electric power to drive said electric motor by the rotation of said spindle; wherein
said generator and said electric motor change the rotational speed of said machining tool from the rotational speed of said spindle by a predetermined ratio determined based on a pole number of said generator and said electric motor.
0. 16. A rotation speed changing apparatus comprising:
an ac generator having an input shaft connectable to a first rotatable portion and rotatable in response to a rotation of the first rotatable portion, said ac generator generating ac electric power when the input shaft is rotated;
an ac motor having an output shaft that is rotated when the ac motor receives the ac electric power generated by the ac generator; and
a case, accommodating and holding the ac generator and the ac motor, the ac generator and the ac motor being arranged in the case along a center axis and a longitudinal direction of the first rotatable portion,
wherein a rotation speed of the output shaft of the ac motor is based on a rotation speed of the input shaft of the ac generator and a ratio, between a number of poles of the ac generator and a number of poles of the ac motor;
further comprising a non-rotating portion, fixing the first rotatable portion and not being rotated by the rotation of the first rotatable portion,
wherein the case comprises a rotation locking member, inserted into a hole formed in the non-rotating portion and constraining the rotation of the case, and
wherein when the speed changing apparatus is connected to the first rotatable portion, the rotation locking member is inserted into the hole.
0. 18. A rotation speed changing apparatus comprising:
an ac generator having an input shaft connectable to a first rotatable portion and rotatable in response to a rotation of the first rotatable portion, said ac generator generating ac electric power when the input shaft is rotated;
an ac motor having an output shaft that is rotated when the ac motor receives the ac electric power generated by the ac generator; and
a case, accommodating and holding the ac generator and the ac motor, the ac generator and the ac motor being arranged in the case along a center axis and a longitudinal direction of the first rotatable portion,
wherein a rotation speed of the output shaft of the ac motor is based on a rotation speed of the input shaft of the ac generator and a ratio, between a number of poles of the ac generator and a number of poles of the ac motor;
the case further comprising:
a first case member rotatably holding the first rotatable portion,
a second case member, connected to the first case member, rotatable with the first rotatable portion and holding the generator and the motor,
a third case member, connected to the second case member, and accommodating the output shaft of the motor, and
a means for clamping and joining the first case member, the second case member and the third case member.
0. 17. A rotation speed changing apparatus comprising:
an ac generator having an input shaft connectable to a first rotatable portion and rotatable in response to a rotation of the first rotatable portion, said ac generator generating ac electric power when the input shaft is rotated;
an ac motor having an output shaft that is rotated when the ac motor receives the ac electric power generated by the ac generator; and
a case, accommodating and holding the ac generator and the ac motor, the ac generator and the ac motor being arranged in the case along a center axis and a longitudinal direction of the first rotatable portion,
wherein a rotation speed of the output shaft of the ac motor is based on a rotation speed of the input shaft of the ac generator and a ratio, between a number of poles of the ac generator and a number of poles of the ac motor;
wherein the ac generator comprises an ac synchronous generator, and
the ac motor comprises an induction motor;
the case further comprising:
a first case member rotatably holding the first rotatable portion,
a second case member, connected to the first case member, rotatable with the first rotatable portion and holding the generator and the motor,
a third case member, connected to the second case member, and accommodating the output shaft of the motor, and
a means for clamping and joining the first case member, the second case member and the third case member.
4. A tool as set forth in
said generator is a three-phase synchronous generator; and
said inductor motor is a three-phase induction motor.
5. A tool as set forth in
a tool attachment part attachable to said spindle for transmitting the rotation of said spindle to said generator;
a tool holding part for rotatably holding said machining tool;
a casing for holding said electric motor, said generator, said tool attachment part, and said tool holding part; and
a locking part for preventing rotation of said casing by engagement with a non-rotating part of said machine tool.
7. A tool as set forth in
a memory for storing a program for driving and controlling said machining tool;
a processor for performing said program; and
a driving circuit for supplying the electric power from said generator to said electric motor in response to a control signal from said processor.
10. A tool as set forth in
data input means for inputting various data required for controlling said electric motor to said control means from outside.
14. A tool holder as set forth in
a tool attachment part attachable to said spindle for transmitting the rotation of said spindle to said generator;
a tool holding part for rotatably holding said machining tool;
a casing for holding said electric motor, said generator, said tool attachment part, and said tool holding part;
a locking part for preventing rotation of said casing by engagement with a non-rotating part of said machine tool.
15. A machine tool as set forth in
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This
Accordingly, when the spindle 46 is rotated at the rotational speed N0, a three-phase alternating current having the frequency F expressed the above formula (1) is supplied to the electric motor 80.
Here, in case where a three-phase induction motor is used as the electric motor 80, as the pole number of the electric motor 80 is p2, the electric motor 80 is rotated by 2/p2 per cycle of the three-phase alternating current.
Therefore, the synchronous rotational speed of the electric motor 80 is expressed by the following formula (2).
N1=120*F/p2 (2)
Accordingly, the relationship of the rotational speed N1 of the cutting tool 100 to the rotational speed N0 of the spindle 46 is expressed by the following formula (3).
N1=N0*p1/p2 [rpm] (3)
As understood from formula (3), the rotational speed N0 of the spindle 46 is changed to the rotational speed N1 expressed by the above formula (3).
As expressed by the formula (3), it is found that by appropriately setting the ratio between the pole number p1 of the generator 70 and the pole number p2 of the electric motor 80, it is possible to freely set the ratio of the rotational speed of the cutting tool 100 to the rotational speed of the spindle 46.
That is, in the case where it is intended to raise the rotational speed of the cutting tool 100 higher than that of the spindle 46, the ratio of the pole number p1/p2 is set larger than 1. When it is intended to reduce the rotational speed of the cutting tool 100 to lower than that of the spindle 46, the ratio of the pole number p1/p2 is set smaller than 1.
Next, an explanation of the driving method of the above configured tool will be made.
When machining a workpiece comprised of a difficult-to-cut material such as aluminum alloy, sometimes the rotational speed of the cutting tool 100 is raised higher than the maximum rotational speed of the spindle 46.
In such a case, the tool 60 is held in advance in the magazine of the automatic tool changer 39 of the machining center 1.
For example, when the maximum rotational speed Nmax of the spindle 46 of the above machining center 1 is 3000 rpm and the rotational speed of the cutting tool 100 is raised to 30,000 rpm, the generator 70 and the electric motor 80 having a ratio of the pole number p1/p2 of 10 are used.
The automatic tool changer 39 attaches the tool 60 automatically to the spindle 46 in the same way as an ordinary tool. Note that an ordinary tool is a tool having a cutting tool clamped by a tool holder.
The rotational speed of the cutting tool 100 held by the tool holder 61 is controlled by the rotational speed of the spindle 46. Specifically, in the machining program downloaded in the numerical control apparatus 51, the rotational speed of the spindle 46 is designated in advance by an S-code in accordance with the rotational speed of the cutting tool 100 held by the tool holder 61. For example, when rotating the cutting tool 100 at the rotational speed of 30,000 rpm, the rotational speed of the spindle 46 is designated as 3000 rpm by the S-code in the machining program.
When the spindle 46 is rotated at the rotational speed of 3000 rpm, the generator 70 generates a three-phase alternating current having a frequency in accordance with the rotational speed of the spindle 46 and the pole number of the generator 70 and electric motor 80.
The electric motor 80 is driven by the three-phase alternating current supplied from the generator 70, while the cutting tool 100 held by the tool holder 61 is rotated at the rotational speed of about 30,000 rpm.
In the above state where the rotational speed of the cutting tool 100 is increased, by moving the workpiece fixed on the table 35 relative to the cutting tool 100 (spindle 46) in accordance with the machining program, the workpiece is cut.
By this, it becomes possible to appropriately cut a workpiece comprised of a difficult-to-cut material such as aluminum alloy.
In this way, according to the present embodiment, the rotational speed of the cutting tool 100 is raised by driving the motor 80 by the electric power generated by the generator 70. Due to this, even if the spindle 46 is rotated at a high rotational speed, heat is not increasingly generated such as in a gear apparatus, so a reduction of the machining tolerance due to the heat can be avoided.
Further, in this embodiment, the rotational speed of the cutting tool 100 is changed by using the generator 70 and electric motor 80. Therefore, it is possible to decrease the cost and noise of the tool 60 compared with the case using a transmission mechanism such as a gear apparatus.
Further, according to this embodiment, the tool 60 can be attached to the spindle 46 and changed by the automatic tool changer 39 in the same way as an ordinary tool. Due to this, it is possible to immediately respond to a need for high speed rotation of the cutting tool 100.
Further, according to this embodiment, the cutting tool 100 is driven by the electric power generated by the rotation of the spindle 46. For this reason, it is not necessary to supply electric power from outside of the tool, so a cable for supplying electric power is not necessary between the spindle 46 and the tool 60.
Further, in this embodiment, a three-phase synchronous generator is used as the generator 70 and a three-phase induction motor is used as the electric motor 80. Due to this, it becomes possible to easily control the rotational speed of the cutting tool 100 by the rotational speed of the spindle 46. That is, since the three-phase synchronous generator generates voltage having a frequency precisely proportional to the rotational speed of the spindle 46 and since the three-phase induction motor drives the cutting tool 100 at a rotational speed proportional to this frequency, the rotational speed of the cutting tool 100 can be easily and precisely controlled by the rotational speed of the spindle 46 and the pole number ratio between the three-phase synchronous generator and the three-phase induction motor.
Further, no position detecting element for detecting the rotational position of a rotor is needed for the electric motor 80. Due to this, no cable is needed between the numerical control apparatus 51 and the tool holder 51, so complete separation of the tool 60 from the spindle 46 becomes possible.
Note that in the above embodiment, the explanation was made of the case of application to high speed machining of an aluminum alloy, but the present invention can be applied to any machining requiring acceleration of the rotational speed of the spindle 46. For example, the present invention can be applied to machining of various super difficult-to-cut materials such as cemented carbide, silicate glass, and ceramics.
Further, in the above embodiment, the explanation was made of the case of increasing the rotational speed of the cutting tool 100 from the rotational speed of the spindle 46, but decreasing the rotational speed of the cutting tool 100 from the rotational speed of the spindle 46 is also possible.
Further, in the above embodiment, the explanation was made of the case of use of a three-phase synchronous generator as the generator 70 and use of a three-phase induction motor as the electric motor 80, but it is also possible to employ a configuration changing the rotational speed of the spindle 46 by a combination of a direct current generator and a direct current motor. The rotational speed of the direct current motor is determined by voltage supplied from the direct current generator and the load. For this reason, it is difficult to directly control the rotational speed of the cutting tool 100 by the rotational speed of the spindle 46.
By measuring the output characteristic and the load characteristic of the direct current generator and the direct current motor in advance, it becomes possible to change the rotational speed of the spindle 46 at a constant speed ratio by the combination of the direct current generator and the direct current motor.
Further, it is possible to use another kind of generator and motor.
Second Embodiment
As shown in
The rectifier circuit 201 rectifies alternating current generated by the generator 70 and supplies it to the electric motor 80. This rectifier circuit 201 is built in, for example, the above casing 65.
The amount of the direct current supplied from the rectifier circuit 201 is defined by the rotational speed of the spindle 46. On the other hand, the rotational speed of the direct current motor can be controlled in accordance with the amount of the supplied current. Accordingly, by controlling the rotational speed of the spindle 46, control of the speed of the electric motor 80 becomes possible.
In this way, according to the present invention, even if an alternating current generator is used as the generator 70 and a direct current motor is used as the electric motor 80, by providing the rectifier circuit 201 at the tool, it is possible to change the rotational speed of the cutting tool 100 from the rotational speed of the spindle 46.
Note that in the above embodiment, a configuration where the rectifier circuit 201 was built in the casing 65 was employed, but it is also possible to employ a configuration where the rectifier circuit 201 is housed in a box or the like and this is attached to the outside of the casing 65.
Further, it is also possible to employ a configuration where a cavity is formed at the casing 65 and the cavity houses the rectifier circuit 201.
Third Embodiment
In the above first and second embodiments, the rotational speed of the cutting tool 100 of the tool 60 is controlled by the rotational speed of the spindle 60, namely, the input rotational speed of the generator 70.
In the present embodiment, an explanation will be made of a configuration enabling control of the rotational speed of the cutting tool 100 regardless of the input rotational speed of the generator 70.
As shown in
The rectifier circuit 302, the inverter 303, and the control circuit 304 are incorporated in the above casing 65. Note that it is possible to employ a configuration where at least some of these rectifier circuit 302, inverter 303, and control circuit 304 are housed in a box mounted on the outside of the casing 65.
Further, it is also possible to employ a configuration where a cavity is formed on the casing 65 and the cavity houses these rectifier circuit 302, inverter 303, and control circuit 304.
Further, the rectifier circuit 302 supplies part of the rectified direct current to the control circuit 304.
The inverter 303 changes the direct current supplied from the rectifier circuit 302 into alternating current for driving the electric motor 80. For example, the inverter 303 is configured by a pulse width modulation (PWM) inverter.
The control circuit 304 is provided with a microprocessor 305, a read only memory (ROM) 306, a random access memory (RAM) 307, a counter circuit 308, an analog-to-digital (A/D) converter 310, and a digital-to-analog (D/A) converter 309.
The ROM 306 stores a control program for controlling the electric motor 80. The control program performs for example variable speed control of the electric motor 80 by field-oriented control.
The RAM 307 stores data for operations of the microprocessor 305.
The microprocessor 305 executes the control program stored in the ROM 306, performs various operations, and outputs control signals 304s to the inverter 300 via the D/A converter 309. The control signals 304s are for example PWM control signals.
The A/D converter 310 converts the value of the current supplied from the inverter 303 to the electric motor 80 detected by a current detector 312 into a digital signal.
The electric motor 80 is provided with a rotational position detector 311. As this rotational position detector 311, for example, an optical rotary encoder or a resolver may be used.
The counter circuit 308 counts pulse signals detected by the rotational position detector 311 in accordance with the rotation of the electric motor 80 and outputs the count to the microprocessor 305.
The above configured control circuit 304 can operate by receiving electric power generated by the generator 70 by the rotation of the spindle 46.
The control circuit 304 receives the rotation and the drive current of the electric motor 80 as input. Due to this, by preparing a desired control program in the ROM 306 of the control circuit 304 in advance, various control of the electric motor 80 becomes possible.
For example, when a synchronous motor is used as the electric motor 80 and it is intended to variably control the speed of this synchronous motor, velocity reference data is set in advance in the ROM 306. By this, speed control of the electric motor 80 becomes possible in accordance with this velocity reference data.
Accordingly, according to the present embodiment, control of the rotational position, the rotational speed, and the torque of the cutting tool 100 becomes possible regardless of the rotational speed of the spindle 46. That is, in the present embodiment, it becomes possible to drive and control the cutting tool 100 separately at the tool side.
Fourth Embodiment
The point of difference between the configuration of the present embodiment and the configuration explained in the third embodiment is that the generator 70 is provided with a rotational position detector 402 and the signal detected by this rotational position detector 402 is input to the microprocessor 305 via a counter circuit 403. The rest of the configuration of the present embodiment is exactly the same as that of the third embodiment.
The rotational position detector 402 is mounted to the input shaft 71 of the generator 70 and detects the rotation of the input shaft 71. As the rotational position detector 402, for example, an optical rotary encoder or a resolver may be used.
By detecting the amount of rotation of the input shaft 71 by the rotational position detector 402, the rotation of the spindle 46 is input to the control circuit 304.
In the control circuit 304, by calculating the difference per unit time of the rotation received from the counter circuit 403, it becomes possible to determine the rotational speed of the spindle 46.
Accordingly, by preparing in advance a program for generating velocity references having a constant speed ratio to the rotational speed of the spindle 46 in the ROM 306, it becomes possible to accurately control the rotational speed of the electric motor 80 with respect to that of the spindle 46. That is, by employing the configuration of the present embodiment, it becomes possible to accurately control the rotational speed of the spindle 46 in the same way as a gear apparatus.
Further, in the control circuit 304, both of the rotational position of the spindle 46 and the rotational position of the electric motor 80 can be obtained, so it becomes possible to make the rotational position of the spindle 46 and the rotational position of the electric motor 80 exactly match.
Fifth Embodiment
Note that the mechanical structure of the tool according to the present embodiment is the same as the above mentioned first embodiment.
The point of difference between the configuration of the present embodiment shown in
The data input unit 501 inputs various types of data for controlling the electric motor 80 from the outside to the control circuit 304.
Specifically, the data input unit 501 can be configured by switches mounted on the casing 65 which are operable from outside the casing 65.
The data input unit 501 can be also configured by a receiving apparatus mounted on the outside of the casing 65 for receiving wireless signals. According to this configuration, it becomes possible to input data in real time while machining by the tool.
The data input from the data input unit 501 includes for example various types of data such as velocity references to the electric motor 80 or control parameters.
In the present embodiment, by employing the above configuration, it is possible to freely change the content of the control of the electric motor 80. For example, when machining conditions are changed, it becomes possible to easily change the rotational speed of the electric motor 80.
Sixth Embodiment
The tool 160 shown in
The tool holder 161 is provided with a secondary battery 110, a processing board 300, and an antenna 141 in addition to the attachment part 62, the casing 65, the generator 70, the electric motor 80, the tool holding part 90, and the locking part 85.
The secondary battery 110 is fixed inside of the casing part 67. This secondary battery 110 stores part of the electric power generated by the generator 70. As the secondary battery 110, for example, a nickel-cadmium battery may be used. Besides this, a nickel-hydrogen battery, a lithium battery, or a small-sized lead storage battery can be also used.
The antenna 141 is fixed on the outside surface of the casing part 65.
The processing board 300 is fixed inside of the casing 65. This processing board 300 is electrically connected with the secondary battery 110 and antenna 141.
In
Further, the tool management system according to the present embodiment is comprised of the tool 160 and a management apparatus 400.
The charging circuit 120, the processing circuit 150, and the transmitting and receiving circuit 140 are formed on the above processing board 300. The charging circuit 120 charges the secondary battery 110 with a part of the electric power generated by the generator 70. This charging circuit 120 is comprised of a rectifier circuit for rectifying the alternating voltage generated by the generator 70, a smoothing circuit for smoothing the ripple included in the output voltage of this rectifier circuit and converting it into appropriate voltage, etc.
The secondary battery 110 supplies the electric power charged by the charging circuit 120 to the power receiving part 170 having the processing circuit 150 and the transmitting circuit 150.
The processing circuit 150 operates by receiving the electric power supplied from the secondary battery 110 and processes information related to the machining of a workpiece by the cutting tool 100.
Here, the information related to the machining of a workpiece by the cutting tool 100 includes, for example, tool information of a predetermined format for identifying the tool 160, monitor information concerning the rotational state of the generator 70 or the electric motor 80 during machining, etc. Further, the information related to the machining of a workpiece by the cutting tool 100 also includes information about the detected rotational position and the detected rotational speed of the electric motor 80.
The tool information includes for example information about the type of the cutting tool 100 such as drill or end mill, size of the cutting tool 100 such as diameter or length, etc.
The monitor information includes information about disconnection or short-circuits of cables in the generator 70 or the electric motor 80, overload of the electric motor 80, etc.
The processing circuit 150 first generates the above tool information of the predetermined format. Further, the processing circuit 150 detects the generated current 70s of the generator 70 or drive current 80s of the electric motor 80, monitors for an irregular state of the generator 70 or the electric motor 80 based on the detected information, adds this monitor information to the tool information, and transmits this tool information to the transmitting and receiving circuit 140.
The transmitting and receiving circuit 140 transmits the data from the processing circuit 150 to the management apparatus 400 as a wireless signal by the antenna 141.
The charging circuit 120, the processing circuit 150, and the transmitting and receiving circuit 140 can be incorporated in the casing 65. Note that it is also possible to house the processing circuit 150 and the transmitting and receiving circuit 140 in a box and mount the box to the outside of the casing 65. Further, it is also possible to employ a configuration where a cavity is formed on the casing 65 and the charging circuit 120 and the processing circuit 150 and the transmitting and receiving circuit 140 are housed in the cavity.
The management apparatus 400 is provided with an antenna 401 which receives data from the antenna 141. This management apparatus 400 is provided with a utility program for monitoring and managing the tool 160 based on the data from the antenna 141. Note that the management apparatus 400 is configured by for example a personal computer.
Further, as shown in
Next, an explanation, will be given of an example of the operation of the above configured tool 160.
The automatic tool changer 39 attaches the tool holder 161 holding the cutting tool 100 to the spindle 46 of the machining center 1. The front end 85a of the locking part 85 is inserted into the engagement hole 47a of the non-rotating part 47, whereby rotation of the casing 65 is prevented.
When the spindle 46 is rotated at predetermined rotational speed from this state, the attachment part 62 of the tool holder 161 is rotated, so the rotation of the spindle 46 is transmitted to the generator 70.
For example, in case where a three-phase synchronous is used as the generator 70, three-phase alternating current is generated.
A part of this three-phase alternating current is charged into the secondary battery 110 by the charging circuit 120.
The processing circuit 150 and the transmitting and receiving circuit 140 become operable by the charge of the secondary battery 110.
When the processing circuit 150 becomes operable, the processing circuit 150 generates the tool information of a predetermined format and transmits this tool information to the transmitting and receiving circuit 140.
The transmitting and receiving circuit 140 transmits the tool information of a predetermined format to the management apparatus 400.
When an irregular state of the generator 70 or the electrical motor 80 occurs while machining a workpiece by the cutting tool 100, irregular state information is transmitted to the management apparatus 400 in addition to the tool information.
Further, if the secondary battery is charged, even after the rotation of the spindle 46 stops, the processing circuit 150 and the transmitting and receiving circuit 140 can transmit various types of data such as tool information or irregular state information to the management apparatus 400.
For example, when the management apparatus 400 has obtained the irregular state information from the transmitting and receiving circuit 140, the management apparatus 400 transmits this irregular state information to the numerical control apparatus 51. When receiving the irregular state information, the numerical control apparatus 51 controls the automatic tool changer 39 so as to detach the tool 160 from the spindle 46.
According to the present embodiment, the tool 160 is provided with the secondary battery 110 and can use the electric power stored in this secondary battery 110 in the power receiving part 170 other than the electric motor 80. Due to this, it is possible to operate various circuits incorporated in or added to the tool 160 regardless of the rotation of the spindle 46, and it is possible to transmit and receive data even during stoppage of the spindle 46.
Further, according to the present embodiment, by the management apparatus 400 collecting information from the tool 160, comprehensive management of the tool 160 becomes possible.
Seventh Embodiment
Note that the mechanical structure of the tool according to the present embodiment is the same as the sixth embodiment. In
In the above sixth embodiment, the management apparatus 400 only received the data from the tool 160, but in the present embodiment, an explanation will be made of a configuration enabling transmission and reception of data between the management apparatus 400 and the tool 260.
As shown in
Further, the rectifier circuit 200, the inverter 210, and the power receiving part 270 are housed in the casing 65. Note that it is possible to employ a configuration where at least some or these rectifier circuit 200, inverter 210, and power receiving part 270 are housed in a box mounted on the outside of the casing 65.
Further, it is also possible to employ a configuration where a cavity is formed in the casing 65, and the rectifier circuit 200, the inverter 210, and the power receiving part 270 are housed in the cavity.
The rectifier circuit 200 rectifies alternating current generated by the generator 70 and supplies it to the inverter 210.
The inverter 210 changes the supplied direct current from the rectifier circuit 200 to alternating current for driving the electric motor 80. For example, the inverter 210 is comprised of a PWM inverter.
The charging circuit 120 charges the secondary battery 110 with part of the electric power generated by the generator 70. This charging circuit 120 is comprised of a rectifier circuit for rectifying the alternating voltage generated by the generator 70, a smoothing circuit for smoothing the ripple included in the output of this rectifier circuit and converting it into appropriate voltage, etc.
The secondary battery 110 supplies the electric power charged by the charging circuit 120 to the electric power receiving part 270.
The electric power receiving part 270 is comprised of a processing circuit part 504 and the transmitting and receiving circuit 240 and is operated by electric power supplied from the secondary battery 110.
The transmitting and receiving circuit 240 transmits the data related to machining of a workpiece by the cutting tool 100 to the management apparatus 400 and receives data related to machining of a workpiece by the cutting tool 100 from the management apparatus 400 via an antenna 241.
The processing circuit part 504 processes the information related to machining of a workpiece by the cutting tool 100. This processing circuit part 504 is provided with a microprocessor 505, a read only memory (ROM) 506, a random access memory (RAM) 507, a counter circuit 508, an analog-to-digital(A/D) converter 510, and a digital-to-analog converter 509.
The ROM 506 stores a control program for controlling the electric motor 80. The control program performs for example variable speed control of the electric motor 80 by field-oriented control. Further, the ROM 506 stores a program for generating tool information of a predetermined format or monitoring an irregular state of the tool, a program for transmitting various types of data to the transmitting and receiving circuit 240 and receiving various types of data from the transmitting and receiving circuit 240, etc.
The RAM 507 stores data for operations of the microprocessor 505, data transmitted from the transmitting and receiving circuit 240, etc.
The microprocessor 505 executes the control program stored in the ROM 506. Specifically, the microprocessor 505 performs various operations, outputs control signals 504s to the inverter 210 via the D/A converter 509, transmits data to the transmitting and receiving circuit 240, and receives data from the transmitting and receiving circuit 240. The control signals 504s are for example PWM control signals.
The A/D converter 510 converts values detected by a current detector 312 of the current supplied from the inverter 210 to the electric motor 80 into a digital signal.
The electric motor 80 is provided with a rotational position detector 311. As this rotational position detector 311, for example, an optical rotary encoder or a resolver may be used.
The counter circuit 508 counts pulse signals detected by the rotational position detector 311 in accordance with the rotation of the electric motor 80 and transmits the count as output to the microprocessor 305.
When the tool 260 is attached to the spindle 46 and the spindle 46 is rotated, the secondary battery 110 is charged by the charging circuit 120. By this, the power receiving part 270 becomes operable by the electric power supplied from the secondary battery 110.
The rotation and the drive current of the electric motor 80 are fed back to the processing circuit part 504, so by preparing in advance a desired program in the ROM 506 of the processing circuit part 504, various control of the electric motor 80 becomes possible.
Further, it is also possible to transmit this control program to the tool 260 from the management apparatus 400, receive this by the transmitting and receiving circuit 240, and store it in the RAM 507.
The microprocessor 505 generates tool information of a predetermined format and transmits the information to the management apparatus 400 through the transmitting and receiving circuit 240. The management apparatus 400 manages this tool information.
Further, the information of the rotational position and the drive current of the electric motor 80 are fed back to the microprocessor 505, so it is also possible to transmit sequentially this feedback information to the management apparatus 400 together with the above tool information.
The management apparatus 400 can monitor data such as the rotational speed and the torque of the cutting tool 100. Due to this, it becomes possible to detect an irregular state such as breakage of the cutting tool 100 in real time based on the monitored various data. Further, it also becomes possible to easily manage the time used for machining.
Further, the microprocessor 505 of the processing circuit part 504 monitors the state of the generator 70 and the electric motor 80. When an irregular state occurs, it transmits this irregular state information to the management apparatus 400. When obtaining the irregular state information, the management apparatus 400 transmits this irregular state information to the numerical control apparatus 51. When the irregular state information is transmitted, the numerical control apparatus 51 controls the automatic tool changer 39 so as to detach the tool 260 from the spindle 46.
As described above, according to the present embodiment, by providing a program for controlling the tool 260 in the processing circuit part 504, it becomes possible to control the tool 260 separately from the spindle 46.
Further, by transmitting a program from the management apparatus 400 to the tool 260 and transmitting not only the simple tool information but various state information while machining to the management apparatus 400, it becomes possible to precisely manage the tool 260.
While the invention has been described by the reference to specific embodiments chosen for purpose of illustration, it should be apparent that numerous modification could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
For example, in the above embodiments, the explanation was given with reference to a cutting tool 100 as a machining tool, but the present invention can also be applied to other machining tools such as a grinding wheel, a polishing tool, or the like.
Katoh, Yasunori, Katoh, Koichi
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