JP4278243B2 - Tool device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a tool device (tool holder) that incorporates an electric motor that is used by being mounted on a machine tool or the like, and more particularly, to a tool device that can be used to start, stop, and set the number of revolutions of an electric motor with only the tool device. .
[0002]
[Prior art]
Machine tools, NC machine tools, machining centers, etc. are equipped with automatic tool changers. Various tools can be selected and various types of machining can be performed, or many tools of the same type can be changed in succession for a long time. Automatic operation is performed. In such a conventional machine tool, after a tool mounted by an automatic tool changer is mounted at a predetermined position such as a spindle of a machine tool body or a tool table, the workpiece is processed by rotating the spindle. It has become. Therefore, for example, even when a minute hole is made in a workpiece, or when a minute chamfering process or polishing of a minute part is performed, the spindle must be rotated. Therefore, unless a special speed increasing device is added, it cannot be rotated beyond the rotation speed of the main spindle, the processing speed is slow, the processing accuracy is lowered, the life of the main spindle is short, the power for the main spindle is wasted, etc. There was a problem.
[0003]
In order to solve such a problem, as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-277238, Japanese Patent Publication No. 6-298, Japanese Patent Publication No. 6-69658, etc., a machine tool main body is provided by an automatic tool changer. It was considered that a tool main body driving motor was built in the tool device itself that is replaceably mounted on the main shaft of the tool.
[0004]
[Problems to be solved by the invention]
However, a rotation control unit that controls the rotation of a tool device equipped with an electric motor is housed in a box-shaped housing and is placed in a table or control panel of a machine tool. When turning on / off the electric motor built in the tool device or changing the rotation speed, it is necessary to operate away from the tool device mounted on the machine tool, which makes operation difficult and lacks safety. Further, when the tool device is replaced, it is necessary to set the rotation speed of the electric motor according to the tool body from the machine tool to the rotation control unit.
[0005]
Therefore, an object of the present invention is to provide a tool device in which the built-in electric motor can be turned on / off and the rotational speed can be changed by the tool device (or tool holder) itself.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a tool device of the present invention is a tool device that is detachably mounted on a machine tool, an electric motor for driving a tool body, and a rotational speed input means for designating a rotational speed of the electric motor. Rotation control means for controlling the rotation drive of the electric motor so as to achieve a designated rotation speed.
[0007]
Preferably, command means for commanding start and stop of the electric motor is further provided.
[0008]
Preferably, a rotation speed display means for displaying the rotation speed of the electric motor is further provided.
[0009]
By adopting such a configuration, since the electric motor can be turned on / off and the rotation speed can be changed with the tool device (or tool holder ), the operation of the device is facilitated. Further, it is not necessary to operate the NC device away from the tool device for changing the rotation speed, and the safety of work is improved.
[0010]
Even if the tool device is replaced, the tool device has a setting means for setting the rotation speed, so there is no need to change the rotation speed of the electric motor from the machine tool, and the setting of the rotation speed is displayed even if the rotation speed is changed. Therefore, confirmation is easy. In addition, since an individual rotation control means is provided for each motor, it becomes easy to design a control device such as an inverter according to the motor rating, type, and the like.
[0011]
Since the variable speed rotation control means is built in the tool device, it is only necessary to supply a single power source from the machine tool to the tool device when changing the tool device.
[0012]
Embodiment
Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a numerically controlled machine tool 1 includes a machine tool body 3 having a spindle 2, an automatic tool changer 4 having a large number of tools 4b, 4c,... The control unit 5 includes a power supply unit 50 that supplies operation power to the mounted tool. A tool 4a is mounted on the spindle 2 by a manipulator (not shown) of the automatic tool changer 4, and a small-diameter drill blade 6 attached to the tip of the tool 4a is about to make a small-diameter hole in the workpiece W. .
[0013]
The tool 4a is provided with a taper shank portion 7 and a gripping portion 7a by a manipulator, and includes a high-frequency electric motor 8 that can be rotated coaxially at a high speed, and the aforementioned drill blade 6 is attached to the tip of the chuck portion 6a. Yes.
[0014]
Further, the tool 4a has a switch 41 for turning on / off the operation of the high-frequency motor 8, a rotation speed input unit 17 for designating the rotation speed of the high-frequency motor 8, and the high-frequency motor 8 operating at a designated rotation speed (number of rotations). A rotation control unit 18 is provided, and a display unit 30 including a liquid crystal display that displays the number of rotations of the high-frequency motor 8 is provided.
[0015]
A connector 11 for supplying operation power to the rotational speed input unit 17, the rotation control unit 18, etc. is provided at a position shifted from the axis of the tool 4 a, and at the same time the tool 4 a is mounted on the spindle 2. It is connected to a receiving connector 12 provided on the machine tool main body 3. As a result, the tool 4a is supplied with operating power from the power supply unit 50, and commands from the NC control device 5 can be transmitted to the tool 4a.
[0016]
FIG. 2 is an explanatory diagram for explaining the external appearance of the tool 4a. In the figure, parts corresponding to those in FIG. In the case of the tool 4a, a switch 41 for turning on / off the operation of the high-frequency electric motor 8, a rotary switch knob as a rotational speed input unit 17 for designating the speed, and a display window of the display unit 30 for displaying the rotational speed of the electric motor 8 Is provided. Around the knob, the set rotational speed is indicated by a numerical scale. The rotation speed input unit 17 may be a volume switch, a keyboard switch, a touch key panel, a dip switch, or the like in addition to the rotary switch.
[0017]
FIG. 3 is a block diagram illustrating a control system of the high frequency motor 8. Power is supplied from the machine tool body 3 through the connector 11 and the on / off switch 41 to the rotation control unit 18 built in the tool 4a. In addition, a speed designation signal is input to the rotation control unit 18 from the rotation speed input unit 17.
[0018]
The rotation control unit 18 decodes the IO signal 19 that decodes the speed designation signal input from the rotation speed input unit 17, the central processing unit 21 that includes a microprocessor, the storage units 22 and 23, the IO unit 24, and the digital signal. The DF conversion unit 25 that outputs a sine wave signal having a designated frequency, the divider unit 26 that generates a three-phase alternating current by the output from the DF conversion unit 25, the output from the divider unit 26 is amplified, and the high-frequency motor 8 Drive unit 27, a drive unit 28 comprising a divider unit 26 and a drive unit 27, a rotation sensor that generates a pulse train according to the rotation of the high-frequency motor 8, and a rotation speed display data (rpm) Decoder unit 2 for converting a digital signal representing the rotational speed set by the rotational speed input unit 17 into rotational speed display data 9. A display unit 30 that displays the set rotation speed and the actual rotation speed in a selectable manner is included. The detected rotation speed of the high-frequency motor 8 is fed back from the decoder 29 to the CPU 21 via the I / O 24. Therefore, feedback control can be performed so that the rotation speed of the high-frequency motor 8 is within a predetermined range. It is.
[0019]
Next, the operation will be described. The operator sets a rotation frequency in advance in the rotation speed input device 17 of each of the tools 4a, 4b, 4c,. If the rotational speed of the electric motor in each tool is one of the rotational speeds and it is not necessary to change each time, it is possible to store this in the ROM 23 and operate the tool at this rotational speed. good. The numerical controller 5 reads a command from an information recording medium such as a programmed paper tape or disk, and controls the machine tool body 3 and the automatic tool changer 4 according to the contents, or controls the rotation controller 18. Output a signal. For example, the automatic tool changer 4 is instructed to select a tool to be used in the first step, and the tool 4a is attached to the main spindle of the machine tool body. After the attachment is completed, the power supply unit 50 is commanded to supply power. Thereby, the high frequency motor 8 starts rotating at the rotation speed set in the rotation speed input device 17 of the tool 4a. The first cutting work is performed with the tool 4a by relatively moving the drill blade 6 and the workpiece W. Next, the high frequency motor 8 is stopped, and the power supply from the power supply unit 50 to the tool 4a is cut off. The automatic tool changer 4 is instructed to change the tool from 4a to 4b. The power is supplied to the tool 4b, and the high frequency motor 8 is rotated at the rotational speed set in the rotational speed input device 17 of the tool 4b. The second cutting work is performed with the tool 4b by relatively moving the drill blade 6 and the workpiece W. Such a process is repeated to finish the programmed cutting process. During this time, the main shaft 2 is stopped without rotating, and machining is performed by high-speed rotation of the high-frequency motor 8.
[0020]
According to the above-described embodiment, since the machining of the hole in the workpiece W is based on the rotation of the high-frequency motor 8 regardless of the rotation of the main shaft 2, the processing can be performed by the high-speed rotation that the main shaft 2 cannot rotate. The speed is high, vibration due to rotation of the main shaft 2 is not generated, machining accuracy is improved, and the main shaft 2 is not damaged, so that the life of the main shaft 2 is extended and power consumption can be saved. The tool 4a incorporating the high-frequency motor 8 can be replaced by the tool changer 4 in the same manner as the other tools 4b, 4c, etc. Control of the high frequency motor 8 can be individually set in advance by the rotation speed input device 17 of each tool, and the program can be automatically operated only by programming a command for starting or stopping. In other words, even if the tool is changed, each tool has a means for setting the number of revolutions, so that no means for changing the number of revolutions of the electric motor from the machine tool is required. The rotational speed of the tool can be set by the rotational speed scale provided on the tool, and the attached drill blade 6 can be checked. In the state where the machine tool is mounted, the set rotational speed is displayed on the display 30 by the display.
[0021]
Further, since the setting of the rotational speed is displayed on the rotational speed scale or the display, it is easy to check the rotational speed whether it is a tool alone or mounted on a machine tool.
[0022]
Moreover, since the rotation control unit 18 of the high-frequency motor 8 is provided in the tool, it is only necessary to supply power from the machine tool 3 when changing the tool.
[0023]
In addition, since the rotation control unit 18 is built in for each tool, there are many types (differences in torque magnitude, rotation speed, motor rotation principle (brushless system, DC system, pulse motor system, etc.), etc.) It is possible to use a rotation control unit having an optimum operating characteristic for each characteristic of the electric motor. For this reason, a single rotation control unit is provided in the machine tool body, and thereby, the degree of freedom in designing the rotation control unit is higher than in the case of controlling various types of high-frequency motors. Equipment design such as (voltage-frequency) characteristics is easy.
[0024]
In the above-described embodiment, a plurality of digital switches, rotary switches, variable resistors, or the like may be used as the rotation speed input unit for designating the rotation speed, and the display device 30 can display numerical values or positions according to the positions and pointers of these knobs. It may be displayed on a scale. Feedback control may be performed by storing a control program in the ROM 23 so that the rotational speed is maintained within a predetermined range centered on the rotational speed set in this way.
[0025]
Although the rotation control unit 18 uses the central processing unit 21 made of a microprocessor, it can be replaced with a hard logic.
[0026]
A grindstone may be attached instead of the drill blade 6 attached to the tip of the tool 4a, and the workpiece W may be chamfered or polished. The tool 4a is not mounted on the main spindle 2, but may be attached to a tool base of a CNC lathe, for example, and drilling or chamfering may be performed on a work held or rotated by the main spindle.
[0027]
Further, the position and orientation of the cutting tool attached to the tool 4a may be changed by the electric motor provided in the tool 4a. You can memorize it.
[0028]
【The invention's effect】
According to the present invention, the tool device incorporates an electric motor that operates separately from the drive system of the main spindle of the machine tool main body, and further includes a rotation control unit that operates the electric motor. For this reason, it is possible to turn on / off the electric motor and change the rotation speed on the tool device side, so that the operation is easy and the safety of the worker is improved. In addition, since each motor has a separate rotation control unit and the rotation control unit does not need to be shared by a plurality of motors, a design of the rotation control unit that matches the rating of the motor is sufficient. Further, since it is sufficient to supply power from the machine tool to the tool device, the rotational speed control is not required, and the NC control program becomes easy.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a numerically controlled machine tool equipped with a tool device.
FIG. 2 is an explanatory view illustrating a tool device.
FIG. 3 is a block circuit diagram of a control system of the tool device.
[Explanation of symbols]
1 Numerical control machine tool,
2 spindles,
3 Machine tool body,
4 Automatic tool changer,
4a Tool (tool device),
5 Numerical control device,
8 High-frequency motor (motor),
11 connector,
12 receiving connector,
17 rotation speed input unit 18 rotation control unit 23 memory (storage means),
30 display device (display means),

Claims (3)

A tool device detachably attached to a machine tool,
An electric motor for driving the tool body;
Rotational speed input means for designating the rotational speed of the electric motor;
Rotation control means for controlling the rotation drive of the electric motor so as to have a specified rotation speed;
A tool device comprising: The tool device according to claim 1, further comprising command means for commanding start and stop of the electric motor. The tool device according to claim 1 or 2, further comprising a rotation speed display means for displaying the rotation speed of the electric motor.

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