JP3675162B2 - Incorrect connection detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to erroneous connection detection that occurs when a plurality of bundles (connectors) having a plurality of signals are connected.
[0002]
[Prior art]
Conventionally, the machine movable shaft in the numerical control apparatus is at an arbitrary machine coordinate position when the power is turned on, and therefore an operation for returning to the origin position of the machine coordinate is required before a predetermined work. Therefore, a machine configuration for returning the machine movable part (table) to the origin will be described.
[0003]
In general, when the table is returned to the origin using a mechanical dog, the configuration shown in FIG. 2 is adopted. That is, the machine movable part (table) TB has an origin return dog DG, which detects an origin limit switch LS near the origin of the machine fixing part MC and overtravel (hereinafter referred to as OT) at both ends of the MC. An overtravel limit switch + side (hereinafter referred to as + OTLS) and − side (hereinafter referred to as −OTLS) are provided, respectively, and a motor and an encoder are provided at one end of a shaft for moving the TB.
[0004]
Next, the origin return operation will be described. When an origin return key (not shown) is pressed, the machine movable portion (table) TB moves toward the origin. After a while, the origin return dog DG steps on the origin limit switch LS near the origin. After recognizing the depression of the origin limit switch LS, a C-phase pulse described later is read to complete the origin return. The aforementioned C-phase pulse is a pulse generated by one rotation of the motor. When there are a plurality of machine movable axes, the origin return operation as described above is performed for each axis.
[0005]
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, an X-axis connector 26, a Y-axis connector 27, and a Z-axis connector 28. These are electrically connected to the address bus and the 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.
[0006]
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, and the RAM 31 temporarily stores data processed by the CPU 29. The I / O 32 connects the CPU 29 with an output device such as a sensor and a valve attached to the machine such as each axis connector 26, 27, 28, and the CPU 29 accesses the I / O 32 to obtain various data. I / O processing.
[0007]
The display device 20 displays machining data and an alarm at the time of overtravel, and the operation device 21 is for inputting data from the outside and is, for example, an operation panel. The servo control interface circuit 22 is responsible for input / output of information that is exchanged between the servo amplifier 23 and the control circuit 19. The servo amplifier 23 includes a servo control circuit and the like, operates a drive unit of a motor 24 that is a servo motor, and transmits information from the encoder 25 that generates a pulse by the drive to the servo control interface circuit 22 for servo control. Based on information from the interface circuit 22, a necessary machining operation is performed on the rotary shaft to which the tool or workpiece is attached. The X-axis connector 26 can be connected to the I / O 32 by combining three signals of the X-axis origin limit switch LS, + OTLS, and -OTLS. Since the Y-axis connector 27 and the Z-axis connector 28 are the same as the X-axis connector 26, description thereof is omitted.
[0008]
Next, the conventional wiring in the connector assignment state and its operation will be described.
[0009]
For each axis, the 33rd and 34th pins of the connector are assigned to + OTLS, the 35th and 36th pins are assigned to the origin limit switch LS, and the 37th and 38th pins are assigned to -OTLS. The switch is closed when the origin limit switch LS is pushed by the dog during the return to origin, and the switch is opened when + OTLS and -OTLS are pushed by the dog during overtravel. Note that the reason for opening is to always detect a malfunction such as disconnection. The connector types and assignments are the same for each axis. Therefore, in the multi-axis machine, the connector parts can be the same regardless of the number of axes.
[0010]
[Problems to be solved by the invention]
However, in the conventional connection described above, there is no difference in the types of connectors on each axis, and since the allocation state of each connector is the same, erroneous connection is likely to occur. As an example, if an X-axis or Y-axis misconnection occurs, if you step on the X-axis origin limit switch LS when returning to the origin, the signal is transmitted to the connector to which the Y-axis origin limit switch LS is recognized. The control circuit 19 in FIG. 3 cannot recognize the signal due to the difference in the axis, and the erroneous connection state cannot be determined until the step + OTLS or −OTLS is stepped on. Furthermore, there is a problem that the higher the origin return speed is, the more the machine movable part (table) TB in FIG. 2 collides with an inner wall (not shown) of the machine tool and the machine is damaged. Further, when the types of connectors are different, erroneous connection can be prevented, but there is a problem that parts management becomes difficult due to a plurality of connectors.
[0011]
In particular, in recent years, the speed of the machine has been increased, and in terms of safety, it is an absolute requirement. Therefore, for this type of request, as described above, with the conventional connection method, is the origin return speed reduced? I had to change the type of connector to eliminate incorrect connections.
[0012]
The present invention has been made to solve the above-described problems, and an object thereof is to provide an erroneous connection detection device that can safely recognize an erroneous connection without changing the type of each connector.
[0013]
[Means for Solving the Problems]
In order to achieve this object, an erroneous connection detection device according to claim 1 includes an origin detection sensor that detects an origin of the movable body provided on a plurality of movable bodies or fixed bodies of a machine tool, and the movable body or An overtravel detection sensor for detecting overtravel of the moving body provided on the fixed body, an operating member for operating each sensor provided on the fixed body or the moving body, and the operating member for detecting each sensor. Based on the identification result of the control unit that can identify the signal of each sensor when operated, the connection unit that connects each sensor and the control unit and has a different connection relationship for each axis wherein a detecting means for detecting the wiring of the connecting portion is incorrect, formed to have a closed circuit when said actuating member is actuated said origin detecting sensor Te, said actuating member Since the formed so as to be open circuit when operated the serial overtravel detection sensor, the control unit can detect the improper connection of the signals from the sensors by opening and closing states of the respective circuits.
[0014]
[0015]
In addition, since the erroneous connection detection device according to the second aspect is configured by the detachable connector, the connection portion can be reconnected to normal wiring in a short time when the erroneous connection is detected.
[0016]
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
The machine tool of the present embodiment is the same as the conventional machine tool shown in FIG.
[0019]
In addition, the present invention provides each connector 26, 27, which is a connection part connecting the conventional control circuit unit 19 shown in FIG. 3 with + OTLS, -OTLS as an overtravel detection sensor, and an origin limit switch LS as an origin detection sensor. Since the allocation state of the 28 wirings is different, this portion will be described.
[0020]
FIG. 1 schematically shows each of the axial connectors 26, 27, and 28 of FIG. 3 as the main part of the present embodiment.
[0021]
FIG. 1A shows an X-axis connector 40. The first pin and the second pin of the connector 40 are to the X-axis origin limit switch LS, the third pin and the fourth pin are to + OTLS, the fifth pin and the sixth pin. Each pin is connected to -OTLS. FIG. 1 (b) shows the Y-axis connector 41. The 7th and 8th pins of the connector 41 are to + OTLS, the 9th and 10th pins are to the Y-axis origin limit switch LS, the 11th and 12th pins. Each pin is connected to -OTLS. FIG. 1 (c) shows the Z-axis connector 42. 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 Z-axis. Each is connected to the origin limit switch LS.
[0022]
Each connector 40, 41, 42 is closed when the origin limit switch LS is pushed by the dog DG as the operating member when returning to the origin, and when + OTLS, −OTLS is pushed by the dog DG during overtravel Are connected to be open. The reason for the opening is that it is always detected in the same way as in the prior art, and also serves as a defect such as disconnection.
[0023]
Next, the operation of the origin return and overtravel detection device in the machine tool of the present embodiment will be described with reference to FIGS. A case where the X-axis connector 40 and the Y-axis connector 41 are erroneously connected will be described. Also, the flowchart of FIG. 4 is activated when an origin return key (not shown) is pressed.
[0024]
When an unillustrated origin return key is pressed, the machine movable portion (table) TB moves toward the origin (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 unit TB is moved until the C-phase is input (S104). If there is a C-phase input, the encoder counter value (not shown) at that time is determined as the origin (S110), and the origin return process is completed. On the other hand, if it is determined in the processing step of S102 that the origin limit switch LS is not ON, it is determined whether + OTLS or -OTLS is ON (S106). In order to move the machine movable portion TB until is turned on, the process proceeds to S102.
[0025]
On the other hand, if it is determined in the processing step of S106 that + OTLS or -OTLS is ON, an overtravel error is notified to the operator via the display device 20 of FIG. 3, and the machine movable unit TB is stopped (S108). ), Ending the origin return process.
[0026]
If the incorrect wiring described above is performed, the X-axis origin limit switch LS is assigned to pins 7 and 8 in FIG. 1, and the Y-axis origin limit switch LS is assigned to pins 3 and 4 in FIG. Will be. Therefore, the switch is opened at the 1st pin and the 2nd pin of the X-axis connector 40 in FIG. 1, the switch is closed at the 3rd pin and the 4th pin, and the switch is closed at the 5th and 6th pins. The Y-axis + OTLS is connected to the first pin and the second pin, the Y-axis origin limit switch LS is connected to the third pin and the fourth pin, and the Y-axis-OTLS is connected to the fifth and sixth pins. Therefore, the switch is closed at the 1st pin and the 2nd pin, the switch is opened at the 3rd pin and the 4th pin, and the switch is closed at the 5th and 6th pins. That is, a + OTLS signal is input from the 3rd pin and the 4th pin to the CPU 29 via the I / O 32. In the processing step of S106, + OTLS is determined to be ON, and the machine movable unit TB is stopped.
[0027]
Note that the processing step of S106 functions as a detection unit, and the CPU 29 in FIG. 3 functions as a control unit.
[0028]
As is apparent from the above description, the erroneous connection detection device of the present embodiment identifies the sensor operated by the CPU 29 when the origin limit switch LS, + -OTLS is operated by the dog DG. Since the connection relationship of the shaft connectors 40, 41, and 42 is different for each axis, it is possible to detect an erroneous connection of the shaft connectors 40, 41, and 42 without changing the type of the connector (S106).
[0029]
The present invention is not limited to this embodiment, and various modifications can be made without departing from the scope of the invention.
[0030]
For example, the connection part used in the erroneous connection detection device of the present embodiment is composed of connectors 40, 41, 42, but each sensor (origin limit switch LS, + -OTLS) and the CPU 29 are connected. Any form may be used, and the lead wire may be soldered directly to the I / O 32 instead of the connector.
[0031]
Further, the + -OTLS as the overtravel detection sensor and the origin limit switch LS as the origin detection sensor of the present embodiment are configured by mechanical limit switches, but any of them can generate a signal. For example, a light emitting element and a light receiving element may be used, or a magnetic sensor may be used.
[0032]
Furthermore, in the flowchart of FIG. 4 showing the operation of the present embodiment, the machine movable portion TB is first moved (S100), but it is determined whether or not + -OTLS is ON in the processing step. After the process of (S106) is completed, the process step of S100 may be performed. In this case, when the origin limit switch LS is ON (YES in S102), it is necessary to perform the same process as the process of S100 before the process of S104.
[0033]
In this way, if the assigned state is different, it will be judged as overtravel from the open / closed state of the origin limit switches LS and + -OTLS before moving the machine movable part TB when returning to the origin. Can be recognized.
[0034]
【The invention's effect】
As is apparent from the above description, the erroneous connection detection device according to claim 1 of the present invention identifies the sensor operated by the control unit when each sensor is operated by the operating member. The connection relationship of the connecting portions is made different for each axis , and the operation member is formed to be a closed circuit when the origin detection sensor is operated, and the operation member operates the overtravel detection sensor. Since the circuit is formed so as to become an open circuit when the signal is generated, the control unit can detect an erroneous connection based on an open / close state of each circuit.
[0035]
Further, in the erroneous connection detection device according to claim 2 of the present invention, since the connection portion is constituted by a detachable connector, when the erroneous connection is detected, it is connected to normal wiring in a short time. You can fix it.
[0036]
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an allocation diagram of each axis connector that is a connection part that connects an origin and an overtravel detection sensor of a machine tool according to the present embodiment and a control part. A Y-axis connector, (c) is a Z-axis connector.
FIG. 2 is an enlarged view of a conventional machine tool origin and overtravel detection device.
FIG. 3 is a control block diagram of a 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 moving part LS Origin limit switch + OTLS Overtravel limit switch + side -OTLS Overtravel limit switch-side DG Dog

Claims (2)

An origin detection sensor for detecting an origin of the movable body provided on a movable body or a fixed body movable by a plurality of axes of the machine tool;
An overtravel detection sensor for detecting overtravel of the movable body provided on the movable body or the fixed body;
An actuating member for actuating each sensor provided on the fixed body or the moving body;
A control unit capable of identifying a signal of each sensor when the operation 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 a detection unit that detects that the wiring of the connection unit is incorrect based on the identification result of the control unit; equipped with a,
The actuating member is formed to be a closed circuit when the origin detection sensor is actuated, and the actuating member is formed to be an open circuit when the overtravel detection sensor is actuated. An erroneous connection detection device.   The erroneous connection detection device according to claim 1, wherein the connection portion is configured by a detachable connector.

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