JPH11262833A - Erroneous connection detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely connect an erroneous connection without changing the kind of each connector by providing a connecting part connecting each sensor and a control part and differentiating a connecting relation for each axis and a detection means detecting that the wiring of the connecting part is erroneous based on a discriminating result of the control part. SOLUTION: An erroneous connection detecting device discriminates a sensor operated by a CPU and differentiates the connecting relation of each axis connector 40, 41, 42 for every axis when an origin limit switch LS and a +-OTLS are operated by a dog DG. As a result, the erroneous connection of each axis connector 40, 41, 42 can be detected without changing the kind of each connector. The connecting part to be used in the erroneous connection detecting device is formed by the connectors 40, 41 and 42, but the connecting part may have any form if each sensor (the origin limit switch LS, the +-OTLS) and the CPU are connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detection of an erroneous connection that occurs when a plurality of bundles (connectors) having a plurality of signals are connected.

[0002]

2. Description of the Related Art Conventionally, since a machine movable axis in a numerical control device is at an arbitrary machine coordinate position when power is turned on, it is necessary to return to an origin position of machine coordinates before a predetermined operation. Therefore, a mechanical configuration for returning the machine movable section (table) to the origin will be described.

[0003] Generally, when a table is returned to the origin using a mechanical dog, a configuration as shown in FIG. 2 is adopted. That is, the mechanical movable section (table) TB has an origin return dog DG, an origin limit switch LS near the origin of the mechanical fixed section MC, and overtravel (hereinafter referred to as OT) at both ends of the MC. Overtravel limit switch + side (hereinafter referred to as + OTLS),
-Side (hereinafter referred to as -OTLS) is provided,
A motor and an encoder are provided at one end of a shaft for moving the TB.

Next, the origin return operation will be described.
When a not-shown origin return key is pressed, the mechanically movable portion (table) TB moves toward the origin. After a while, the home return dog DG steps on the home limit switch LS near the home. After recognizing that the origin limit switch LS has been pressed, a C-phase pulse described later is read to complete the origin return. The C-phase pulse described above is a pulse generated by one rotation of the motor. When there are a plurality of mechanically movable axes, the origin return operation as described above is performed for each axis.

The operation of the machine tool described above is realized by the circuit shown in FIG. The circuit of the machine tool includes a control circuit 19, a display device 20, an operation device 21, a servo control interface circuit 22, a servo amplifier 23,
It is composed of an X-axis connector 26, a Y-axis connector 27, and a Z-axis connector 28, which are electrically connected to an address bus and a data bus. The control circuit 19 includes a CPU 29 as a control unit, a ROM 30, a RAM 31
And an I / O 32.

The CPU 29 is a central processing unit that processes various input signals through an address bus and a data bus.
The ROM 30 stores data such as programs,
Numeral 31 is for temporarily storing data processed by the CPU 29, and I / O 32 is for each axis connector 26, 27, 2
An output device such as a sensor and a valve attached to a machine such as 8 is connected to the CPU 29, and the CPU 29 accesses the I / O 32 to perform input / output processing of various data.

A display device 20 displays processing data and an alarm at the time of overtravel, and an operation device 21 is for inputting external data, for example, an operation panel. The servo control interface circuit 22 is responsible for input and output of information passing between the servo amplifier 23 and the control circuit 19. The servo amplifier 23 operates a drive unit of a motor 24 composed of a servo control circuit or the like and composed of a servo motor, and transmits information from an encoder 25 that generates a pulse by driving the servo control interface circuit 2.
2 and the information from the servo control interface circuit 22 is used to perform the necessary machining operation on the rotary shaft on which the tool or the work is mounted. Also, the X-axis connector 26
Axis home limit switch LS, + OTLS, -OTLS
Are combined and can be connected to the I / O 32. Since the Y-axis connector 27 and the Z-axis connector 28 are the same as the X-axis connector 26, the description is omitted.

Next, a description will be given of a conventional wiring in a connector-assigned state and its operation.

For each axis, pins 33 and 34 of the connector are + OTLS, pins 35 and 36 are the origin limit switch LS, and pins 37 and 38 are -OTL.
S is assigned to each. When the home limit switch LS is pushed by the dog at the time of home return, the switch is closed, and at the time of overtravel, + OTLS, -OT
The switch is opened when LS is pushed by the dog. The reason for the open state is to always detect a defect such as a disconnection. The type and assignment of connectors are the same for each axis. Therefore, the components of the connector can be the same regardless of the number of shafts in the multi-axis machine.

[0010]

However, in the above-described conventional connection, there is no difference in the type of the connector of each axis, and since the assignment state of each connector is the same, erroneous connection easily occurs. As an example, if the X-axis and Y-axis are erroneously connected, when the X-axis origin limit switch LS is depressed at the time of origin return, the signal becomes Y axis origin limit switch LS
Is transmitted to the assignment destination of the connector that recognizes the signal, and the control circuit 19 in FIG.
Or, the erroneous connection state cannot be determined until the user steps on the OTLS. Furthermore, the higher the home position return speed, the more FIG.
In this case, there is a problem that the machine movable part (table) TB collides with an inner wall (not shown) of the machine tool and the machine is damaged. Also,
If the type of the connector is different, erroneous connection can be prevented, but there is a problem in that parts management becomes difficult due to a plurality of connectors.

In particular, in recent years, the speed of machines has been increased, and safety is an absolute requirement.
To meet this kind of demand, as described above, in the conventional connection method, it was necessary to reduce the homing speed or change the type of connector to eliminate erroneous connection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide an erroneous connection detection device capable of safely recognizing erroneous connection without changing the type of each connector. And

[0013]

In order to achieve this object, an erroneous connection detection device according to claim 1 detects an origin of a plurality of movable bodies or a fixed body of a machine tool. An origin detection sensor, an overtravel detection sensor provided on the moving body or the fixed body for detecting overtravel of the moving body, and an operating member for operating the sensors provided on the fixed body or the moving body. And a control unit that can identify a signal of each sensor when the operating member operates each sensor, and a connection unit that connects each sensor and the control unit and that has a different connection relationship for each axis. Detecting means for detecting that the wiring of the connection unit is incorrect based on the identification result of the control unit.

Therefore, when each of the sensors is actuated by the actuating member, the sensor operated by the control unit is identified. However, since the connection relationship of the connection unit is different for each axis, the detection means An erroneous connection of the connection part can be detected.

Further, according to a second aspect of the present invention, there is provided an erroneous connection detecting apparatus,
Since the connection portion is constituted by a detachable connector, when the erroneous connection is detected, it is possible to reconnect to a normal wiring in a short time.

Further, the erroneous connection detection device according to claim 3 is
Since the operating member is formed to be in a closed circuit when the origin detection sensor is operated, and the operating member is formed to be in an open circuit when the overtravel detection sensor is operated, The control unit can detect an erroneous connection from a signal from each of the sensors based on an open / close state of each of the circuits.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

The machine tool according to the present embodiment is the same as the conventional machine tool shown in FIG. 2, and a description of the configuration will be omitted.

Further, the present invention relates to the conventional control circuit 19 shown in FIG. 3 and + OT as an overtravel detection sensor.
LS, -OTLS, each connector 26 which is a connection portion connecting the origin limit switch LS as an origin detection sensor,
Since the assignment states of the wires 27 and 28 are different, the portions will be described.

FIG. 1 schematically shows each of the shaft connectors 26, 27, and 28 of FIG. 3 which is a main part of the present embodiment.

FIG. 1A shows an X-axis connector 40,
Pins 1 and 2 of the connector 40 go to the X-axis origin limit switch LS, pins 3 and 4 go to + OTLS, 5
The No. 6 pin and the No. 6 pin are connected to -OTLS, respectively. FIG. 1B shows the Y-axis connector 41. The 7th pin and the 8th pin of the connector 41 are connected to + OTLS, the 9th pin,
The 10th pin is connected to the Y-axis origin limit switch LS, and the 11th and 12th pins are connected to -OTLS. FIG. 1C shows the connector 42 of the Z-axis. The 13th and 14th pins of the connector 42 are to + OTLS, the 15th and 16th pins are to −OTLS, and the 17th and 18th pins are the Z-axis. Each is connected to the origin limit switch LS.

Each of the connectors 40, 41, and 42 is closed when the origin limit switch LS is pressed by a dog DG as an operating member when returning to the home position, and + OTLS and -OTLS are pressed by the dog DG during overtravel. The switch is thus connected to be open. The reason for the open state is to always detect a failure such as a disconnection as in the conventional case.

Next, the operation of the home position return and overtravel detecting device in the machine tool according to the present embodiment will be described with reference to FIGS. The X-axis connector 40
The case where the connector 41 and the Y-axis connector 41 are erroneously connected will be described. The flowchart in FIG. 4 is started when a not-shown origin return key is pressed.

When a home return key (not shown) is depressed, the mechanically movable section (table) TB moves toward the home (step 100; hereinafter, step is abbreviated as S). Next, it is determined whether or not the origin limit switch LS is ON (S102). If the origin limit switch LS is ON, the machine movable section TB is moved until there is a C-phase input (S104). When the C-phase is input, the counter value of the encoder (not shown) at that time is determined as the origin (S
110), the origin return processing ends. On the other hand, S102
If it is determined that the origin limit switch LS is not ON in the processing step of +, + OTLS or -OTLS is set to O
N is determined (S106). If it is not ON, it is not overtravel, so the origin limit switch LS is set to O.
In order to move the mechanically movable portion TB until N is reached, the process proceeds to S102.

On the other hand, in the processing step of S106, + OTL
If it is determined that S or -OTLS is ON, the operator is notified of an overtravel error via the display device 20 of FIG. 3 and the mechanical movable section TB is stopped (S108), and the origin return processing is terminated.

When the above-described incorrect wiring is performed, the origin limit switch LS of the X axis is moved to the 7th and 8th pins in FIG.
The origin limit switch LS of the shaft is assigned to the third and fourth pins in FIG. Therefore, the switch is opened at the 1st and 2nd pins of the X-axis connector 40 of FIG. 1, the switch is closed at the 3rd and 4th pins, and the switch is closed at the 5th and 6th pins. The Y-axis + OTLS should go to the 1st and 2nd pins.
When the Y-axis origin limit switch LS is
Since the Y-axis-OTLS is connected to pin 6, the switch is closed at pin 1, pin 2 and the switch is open at pin 3, pin 4 and the switch is open at pin 5, pin 6. It will be closed. In other words, I /
Since the + OTLS signal has been input to the CPU 29 via O32, the + OTLS
Is determined to be ON, and the machine movable section TB stops.

Incidentally, the processing step of S106 functions as a detecting means, and the CPU 29 of FIG. 3 functions as a control unit.

As is apparent from the above description, the erroneous connection detecting device of the present embodiment identifies the sensor operated by the CPU 29 when the origin limit switches LS, + -OTLS are operated by the dog DG. But,
Since the connection relationship of each axis connector 40, 41, 42 is different for each axis, erroneous connection of each axis connector 40, 41, 42 can be detected without changing the type of connector (S106).

The present invention is not limited to this embodiment, and various modifications can be made without departing from the gist of the invention.

For example, the connection portion used in the erroneous connection detection device of the present embodiment is composed of connectors 40, 41, and 42, and each sensor (origin limit switch LS,
+ -OTLS) and the CPU 29 may be connected in any form, and a lead wire may be directly soldered to the I / O 32 instead of the connector.

Further, the + -OTLS as the overtravel detection sensor and the origin limit switch LS as the origin detection sensor in the present embodiment are constituted by mechanical limit switches. Any of them may be used, for example, a light emitting element and a light receiving element, or a magnetic sensor.

Further, in the flowchart of FIG. 4 showing the operation of the present embodiment, the mechanical movable section TB is first moved (S100), but the processing steps are performed by +-
The process of S100 may be performed after the process of determining whether or not OTLS is ON (S106) is completed. In this case, if the origin limit switch LS is ON (YES in S102), it is necessary to perform the same processing as in S100 before the processing in S104.

In this manner, if the allocation state is different, the machine is operated because the overtravel is determined from the open / closed state of the origin limit switches LS and + -OTLS before the movement of the machine movable part TB during the return to origin. Erroneous connection can be recognized without any error.

[0034]

As is apparent from the above description, the erroneous connection detecting device according to the first aspect of the present invention is configured such that when each of the sensors is operated by the operating member, the sensor operated by the control unit is activated. Although it is identified, the connection relationship of the connection portion is different for each axis, so that the detecting means can detect an erroneous connection of the connection portion.

In the erroneous connection detection device according to the second aspect of the present invention, since the connection portion is constituted by a detachable connector, when the erroneous connection is detected, a normal wiring can be quickly established. You can reconnect to.

Further, in the erroneous connection detecting device according to claim 3 of the present invention, the operating member is formed so as to form a closed circuit when the origin detecting sensor is operated, and the operating member detects the overtravel. Since the sensor is formed so as to be in an open circuit when the sensor is operated, the control unit can detect a signal from each of the sensors by detecting an erroneous connection based on an open / close state of each of the circuits.

[Brief description of the drawings]

FIG. 1 is an allocation diagram of each axis connector which is a connection unit connecting a control unit and an origin and overtravel detection sensor of a machine tool according to the present embodiment, wherein (a) is an X-axis connector;
(B) is a Y-axis connector, and (c) is a Z-axis connector.

FIG. 2 is an enlarged view of a conventional origin and overtravel detection device of a machine tool.

FIG. 3 is a control block diagram of the machine tool.

FIG. 4 is a flowchart showing the operation of the present embodiment.

[Explanation of symbols]

 19 Control circuit 40 X-axis connector 41 Y-axis connector 42 Z-axis connector TB Machine table MC Machine movable part LS Home limit switch + OTLS Overtravel limit switch + side -OTLS Overtravel limit switch -side DG dog

Claims (3)

[Claims] An origin detection sensor provided on a movable body or a fixed body movable by a plurality of axes of a machine tool, for detecting an origin of the movable body; and the movement provided on the movable body or the fixed body. An overtravel detection sensor for detecting overtravel of the body, an operating member provided on the fixed body or the moving body for operating the sensors, and a signal from each sensor when the operating member operates each sensor. A connection unit that connects the sensors and the control unit and has a different connection relationship for each axis; and the wiring of the connection unit is incorrect based on the identification result of the control unit. An erroneous connection detection device, comprising: 2. The erroneous connection detection device according to claim 1, wherein the connection portion is constituted by a detachable connector. 3. The circuit according to claim 1, wherein the operating member is configured to form a closed circuit when operating the origin detection sensor, and is configured to form an open circuit when the operating member operates the overtravel detection sensor. The erroneous connection detection device according to claim 1, wherein