JP4428769B2 - Machine Tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a machine tool that is used with a tool device (tool holder) that incorporates an electric motor, and in particular, detects a connection abnormality in a connector between a tool device and a machine tool, and eliminates this. It relates to machine improvements.
[0002]
[Prior art]
In a machine tool with an automatic tool changer, when a tool device with a built-in electric motor is automatically mounted on the spindle of the machine tool body, connectors are attached to the tool side and the spindle side, respectively. At the same time as mounting, both connectors are inserted so that the electric motor of the tool device is electrically controlled. In this case, when a tool other than the tool device is attached to the spindle and machining is performed, chips, cutting water (oil), and the like due to this may adhere to the connector on the spindle side. Therefore, for example, in “Electric motor built-in tool connector device” described in Japanese Utility Model Publication No. 4-19741, chips and dust are removed before connecting the connector, and damage due to poor contact or overcurrent (short circuit) is caused. I try to prevent it. It is also conceivable to cover the connector part with a lid.
[0003]
[Problems to be solved by the invention]
However, when the tool device is automatically changed, the connectors are exposed for connection. At this time, cutting water or the like may be applied to the connector. The machine tool cannot discriminate even if the cutting water is applied to the connector. In such a case, leakage or a short circuit may occur.
[0004]
Therefore, the present invention discriminates abnormalities such as electric leakage and overcurrent when the tool device is replaced, and if there are abnormalities, the connector portion is automatically cleaned to remove foreign matters such as cutting water. The purpose is to provide a machine.
[0005]
Another object of the present invention is to provide a machine tool that notifies an operator when an abnormality cannot be recovered by cleaning a connector, and protects the operator and electrical equipment.
[0006]
Another object of the present invention is to provide a machine tool in which foreign objects are less likely to enter a connector during a machining process.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a machine tool of the present invention is a machine tool in which a tool device incorporating an electric device is replaceably mounted on a machine tool body, and the tool device and the tool device are exchanged along with the replacement of the tool device. At least a pair of detachable connectors for connecting wires between machine tool bodies, an abnormality detecting means for detecting abnormalities such as overcurrent and leakage in the wiring, and stopping the machine tool when the abnormalities are detected. And an abnormality handling control means for cleaning the connector.
[0008]
By adopting such a configuration, when a leakage or overcurrent abnormality in the electrical wiring system from the machine tool body to the tool device is detected, the connector part that is likely to cause the abnormality is cleaned, so the abnormality is Can be automatically restored. If the abnormality is not resolved, the operator can be notified.
[0009]
Preferably, the control means applies a test current to the tool device immediately after the tool device is replaced. As a result, it is possible to determine a leakage or a short circuit before flowing a large current through the electric motor, so that it is possible to prevent the electric circuit, device, and electric equipment of the machine tool from being destroyed.
[0010]
Preferably, the control means separates the tool device from the machine tool main body, removes the connector, and blows air on a connection terminal portion of the connector to clean it.
[0011]
With such a configuration, cutting water (cutting fluid), chips, dust, and the like can be removed.
[0012]
Preferably, the control means attaches the tool device to the machine tool body again after the cleaning, performs a test operation such as supplying a test current, and displays the abnormality when the abnormality is detected again, and detects the abnormality. If not, return the machine tool to the machine process.
[0013]
With such a configuration, it is possible to confirm whether or not the abnormality has been eliminated by cleaning the connector, and to ensure the safety of the work process.
[0014]
Preferably, the electric device is an electric motor for driving a tool main body, and the abnormality detecting means is an overcurrent detecting device or an electric leakage detecting device provided in an inverter that rotationally drives the electric motor.
[0015]
Preferably, the control device further blows air from the inside of the connector to the outside of the connector through the gap of the connector when the machine tool is in a machining process, and chips, cutting fluid, etc. generated in the machining process Prevent foreign material from entering the connector.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
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 number of tool devices (tool holders) 4b, 4c,. It consists of a numerical control device 5 that is controlled by a command or the like. A tool device 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 device 4a is used to make a small diameter hole in the workpiece W. It is said.
[0017]
The tool device 4a is provided with a taper shank portion 7 and a gripping portion 8 by a manipulator, and includes a high-frequency motor 9 that can be rotated coaxially at high speed, and the above-described drill blade 6 is attached to the tip of the chuck portion 10. ing.
[0018]
A connector 11 for connecting to the high-frequency electric motor 9 is provided at a position shifted from the axis of the tool device 4a. The tool device 4a is mounted on the main shaft 2 and at the same time is provided on the machine tool main body 3. The connector 12 is connected. An output end of a controller 17 is connected to the receiving connector 12.
[0019]
As shown in FIG. 2, the receiving connector 12 is provided with a fitting hole 12c and a ring electrode 12a that open downward, and a flow path 12b for blowing air from the ring electrode 12a. A tube 14, an electromagnetic on-off valve 15, and an air pressure source 16 are connected to the flow path 12 b via a connector 13. As shown in FIG. 6 which will be described later, this is because the electromagnetic on-off valve 15 is moved for a short time immediately before the tool device 4a is mounted on the main shaft 2, that is, immediately before the pin electrode 11a of the connector 11 is inserted into the ring electrode 12a. The air is turned on to blow out air from the ring electrode 12a, and thereby air purge of chips, dust, oil, etc. is performed to make the electrical connection more reliable.
[0020]
FIG. 3 is a block diagram showing the control system. The numerical controller 5 includes a ROM 5a including a startup program, a CPU 5b that executes the program, a RAM 5c that stores data and programs, a hard disk (HD) 5d that stores data, a display unit 5e that displays information, a management computer, and the like. The communication interface 5f that performs communication and the IO unit 5g that performs data communication with the controller 17 are configured. The numerical control device 5 controls the machine tool main body 3, the tool changer 4, the controller 17 and the like according to a workpiece W machining program stored in advance. The controller 17 receives the control signal from the numerical controller 5 and controls the high frequency motor 9. The controller 17 detects abnormalities such as an ACK signal, an overcurrent (or short circuit), and a leakage current to the interface unit 18, the IO unit 19, and the numerical control device 5, which are photocouplers for inputting a control signal from the numerical control device 5. A signal output unit 20 including a relay for outputting an abnormal signal to be notified, a central processing unit 21 including a microprocessor, storage units 22 and 23, an IO unit 24, a sine wave having a frequency specified by decoding a digital signal DF conversion unit 25 that outputs a signal, divider unit 26 that generates a three-phase alternating current by the output from the DF conversion unit 25, a drive unit 27 that drives the high-frequency motor 9 by amplifying the output from the divider unit 26, and the divider unit 26, a drive unit 28 comprising a drive unit 27, a decoder unit 29 for displaying the rotational speed, a display unit 30, etc. Going on. The drive unit 28 can be configured by a so-called inverter circuit. The controller 17 and the high frequency motor 9 are connected by electrical wiring 31 via connectors 11 and 12.
[0021]
The abnormality detection device 32 detects that the output current of the drive unit 27 is an overcurrent or the occurrence of electric leakage between the system of the electrical wiring 31 and the frame / ground of the machine tool. This detection output sets an abnormality occurrence flag indicating an abnormality of the wiring 31 system in the IO unit 24.
[0022]
The CPU 21 supplies a test current to the high-frequency motor 9 after replacing the tool device in accordance with a command from the numerical control device 5, and determines whether or not an abnormality has occurred based on the output of the abnormality detection device 32. When the abnormality occurrence flag is detected, the operation of the drive unit 28 is stopped, and the high frequency motor 9 is stopped. A code representing the cause of the abnormality is displayed on the display 30. Further, the CPU 21 notifies the numerical control device 5 via the signal output unit 20 of abnormality (overcurrent, electric leakage) in the wiring 31 system. Similarly, abnormalities during operation are detected and processed by the abnormality detection device 32.
[0023]
The normal operation of the numerical control device 5 includes, for example, a pre-programmed file held in the RAM 5c, and the CPU 5b sequentially reads a group of commands according to the machining procedure, and the machine tool body 3 and the automatic tool changer according to the contents thereof. 4 is controlled. A control signal is output to the controller 17. When the abnormality of the apparatus is determined, information is transmitted to a management computer (not shown) via the communication interface 5f.
[0024]
FIG. 4 is a flowchart illustrating an example of a post-replacement test in which the numerical controller 5 confirms whether or not an abnormality has occurred after replacing the tool device. The numerical control device 5 performs the post-replacement test shown in FIG. 4 when the tool changer 4 completes the replacement (attachment) of the tool device incorporating the electric motor.
[0025]
First, the numerical controller 5 causes the controller 17 to supply a low level test voltage or a low level test current to the electric motor 9 for a predetermined short time (S2). Thereby, it is determined whether or not an abnormality detection indicating an abnormality of the wiring 31 system is notified from the controller 17 (S4). If an abnormality is detected, an abnormality process is performed (S4; Yes). For example, the controller 17 is instructed immediately to stop the supply of the test current, and the operation of the machine tool main body 3 is stopped. The power supply of the corresponding power supply system is shut off as necessary (S6). The abnormality detection is displayed on the display 5e and the abnormality is notified. The operator confirms the cause of the abnormality such as the foreign matter of the connectors 11 and 12. If necessary, the management computer in the factory is notified of the abnormality (S8). If necessary, an abnormality detection process (FIG. 5) described later can be performed to try to solve the trouble.
[0026]
If no abnormality occurs (S4; No), the test after the replacement is finished, and the operation shifts to normal operation (work).
[0027]
By passing through such a test process, it becomes possible to avoid damage to the electric circuit and equipment due to overcurrent (or short circuit) or electric leakage when a foreign object enters the connector during tool device replacement.
[0028]
FIG. 5 is a flowchart for explaining the control operation when the numerical controller 5 receives a notification of abnormality detection from the controller 17 during operation.
[0029]
As described above, notification of abnormality detection after tool device replacement or operation sets an interrupt flag indicating an abnormality in the wiring 31 system in the numerical control device 5. The cause of abnormality in the wiring 31 system is a high possibility of foreign matter entering the connectors 11 and 12.
[0030]
When the CPU 5b of the numerical controller 5 determines the setting of the wiring 31 system abnormality flag (S12; Yes), the CPU 5b saves the control data currently set for the control of the machine tool to the built-in hard disk device 5d. Thereby, the subsequent operation can be resumed (S14). In order to remove the tool device 4a, the workpiece W is moved to a safe place (S16). The tool 4a is removed from the main shaft 2 by a manipulator (not shown) of the tool changer 4, and the tool 4a is held at a slightly lowered position.
[0031]
Thereby, as shown in FIG. 6, between the connectors 11 and 12 is opened (S18). The air valve 15 is opened and air is strongly blown from the ring electrode 12a portion of the connector 12 toward the lower pin electrode 11a to clean the connector portion. As a result, the cause of short circuit / leakage such as cutting water and dust is blown away. Note that the air valve 15 may be intermittently repeated to repeat spraying a plurality of times (S20). After the cleaning, the tool device 4a is attached to the main shaft 2 while blowing air weakly so that foreign matter does not enter the connector 11 (S22). After the mounting, the controller 17 is supplied with a drive current for the low-level electric motor 9 for test for a short time (S24). It is determined whether or not an abnormality has been detected from the detector 32 of the controller 17 (S26). When the abnormality flag is not set (S26; No), the operation data is reset, the workpiece W is returned to the original position, and the machining is resumed. As will be described later, after resuming operation, air is supplied to the inside of the connector 12 during processing or at all times, and air is weakly blown out of the connector through the gap between the connectors 11 and 12, so that foreign matter can enter. Can be prevented (S28).
[0032]
When the abnormality flag is set again (S26; Yes), an abnormality process is performed and a standby state is entered. For example, as abnormality processing, abnormality detection notification (alarm), display of a code indicating the type of abnormality detection, recording of abnormality code / abnormality occurrence time, abnormality notification to a process management computer (not shown), to abnormality occurrence system (S30).
[0033]
In this way, the above-described machine tool blows air from the connector 12 when the tool device is attached to the machine tool body, thereby preventing chips and dust from adhering. Further, when a foreign matter enters the connector and an abnormality is detected, the connector is cleaned, and when the abnormality is resolved, the operation is resumed.
[0034]
FIG. 7 shows another configuration example of the connector 12, which is suitable when air is constantly passed through the connector. That is, in the state where the connectors 11 and 12 are connected, by actively supplying air during work of the workpiece to the inner side of the connector 12, air is blown out from the gap between the connectors 11 and 12, Cutting water (cutting fluid), chips, dust and the like are prevented from entering the gap between the connectors 11 and 12. In the figure, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.
[0035]
In FIG. 7, the receiving connector 12 is provided with a fitting hole 12c and ring electrodes 12a and 12a that open downward. In addition, an air flow path 12 d that communicates between the opposed surfaces of the flow path 12 b or the fitting hole 12 c and the connector 11 is formed in the approximate center of the insulator located between the ring electrodes 12 a and 12 a. The channel 12b communicates with the openings of the ring electrodes 12a and 12a and the air channel 12d to supply air. A tube 14, an electromagnetic on-off valve 15, and an air pressure source 16 are connected to the flow path 12 b via a connector 13.
[0036]
As described above, after the tool device 4a is mounted on the main shaft 2, that is, before the pin electrode 11a of the connector 11 is inserted into the ring electrode 12a, the electromagnetic on-off valve 15 is turned on for a short period of time so that air is supplied to the ring electrode. 12a blows out air and strongly blows air when connecting to remove chips, dust and oil. Thereafter, the connectors 11 and 12 are connected. After both connectors are connected, air is continuously supplied by reducing the opening of the electromagnetic on-off valve 15, using an additional electromagnetic valve (not shown), or lowering the pressure of the air pressure source 16. During the process, air is blown out weakly from the air flow path 12d of the connector 12. This air escapes from the gap between the connectors 11 and 12 to the outside. Thereby, chips, dust, oil and the like are prevented from entering the inside through the gap between the connectors 11 and 12. Therefore, the electrical connection can be made more reliable.
[0037]
In addition, a tool apparatus is not restricted to what incorporates an electric motor. For example, the present invention can also be applied to a device that incorporates an electric device such as an electromagnet, a vibrating body, laser machining, or an electric discharge machining device, and receives power supply and signals from the machine tool body via a connector.
[0038]
In the embodiment, a pair of connectors is shown, but the present invention is not limited to this, and the tool device and the machine tool main body may be connected by a plurality of pairs (a plurality of sets) of connectors. . The shape and number of poles of the ring electrode 12a and the shape and number of poles of the pin electrode 11a may be arbitrary. The cover part 11b may be omitted.
[0039]
【The invention's effect】
As described above, when the tool device is replaced, the machine tool of the present invention discriminates a leakage or a short circuit before supplying a large current from the machine tool to the electric motor built in the tool device or during operation. Therefore, it is possible to avoid the electric shock of the worker and the breakage of the electrical equipment of the machine tool. Further, when a leakage or short circuit occurs, the operator can know this by a display or a notification.
[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 enlarged cross-sectional view showing a portion of the connectors 11 and 12;
FIG. 3 is a block diagram illustrating a control system.
FIG. 4 is a flowchart illustrating a test after tool device replacement.
FIG. 5 is a flowchart for explaining processing when abnormality detection is performed during operation.
FIG. 6 is an explanatory diagram for explaining cleaning of a connector.
FIG. 7 is an explanatory view showing another configuration example of the connector 12;
[Explanation of symbols]
1 Numerically controlled machine tool,
2 spindles,
3 Machine tool body,
4 Automatic tool changer,
4a Tool (tool device),
5 Numerical control device,
9 High frequency motor (motor),
10 chuck,
11 connector,
12 receiving connector,
17 Controller

Claims (6)

A machine tool that replaceably mounts a tool device incorporating an electric device to a machine tool body,
At least a pair of detachable connectors for connecting wires between the tool device and the machine tool main body in accordance with the replacement of the tool device;
An anomaly detecting means for detecting an anomaly such as overcurrent or electric leakage in the wiring;
Control means for stopping the machine tool when the abnormality is detected and cleaning the connector;
Machine tool equipped with. The machine tool according to claim 1, wherein the control means applies a test current to the tool device immediately after replacement of the tool device. 2. The machine tool according to claim 1, wherein the control unit separates the tool device from the machine tool main body, removes the connector, and blows air on a connection terminal portion of the connector for cleaning. 3. The control means performs the test operation by attaching the tool device to the machine tool body again after the cleaning, displays an abnormality when the abnormality is detected again, and displays a machine tool when the abnormality is not detected. The machine tool according to claim 1, wherein the machine tool is returned to the machining process. The electric device is an electric motor that drives a tool body,
The machine tool according to any one of claims 1 to 4, wherein the abnormality detection means is an overcurrent detection device or a leakage detection device provided in an inverter that rotationally drives the electric motor. The machine tool according to any one of claims 1 to 5, wherein the control device further blows air from the inside of the connector to the outside of the connector through a gap of the connector when the machine tool is in a machining process. .

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