JP2010005758A - Door lock control device for machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a door lock control device for a machine tool, which disables unlocking as long as a spindle cannot be confirmed to have stopped rotating, thus disabling entry with the spindle rotating. <P>SOLUTION: The door lock control device 1 for the machine tool M includes a lock mechanism 10 capable of locking a door of a protective cover in a closed state, a lock mechanism control circuit 16 to instruct the lock mechanism 10 for locking or unlocking, a spindle control circuit 15 to output a spindle rotation command off signal 24 when a spine rotation command 20 is turned off, and a rotation detector 28 to output a detection signal 26 concerning the rotation of the spindle X; wherein the spindle control circuit 15 outputs a spindle rotation stop signal 30 when the detection signal 26 indicates a rotation stop state and outputs an alarm signal 32 if the detection signal 26 cannot be received normally, and the lock mechanism control circuit 16 can instruct the lock mechanism 10 for unlocking when the spindle rotation command off signal 24 and the spindle rotation stop signal 30 have been received without receiving the alarm signal 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a door lock control device that controls a door lock mechanism installed on a protective cover surrounding a machining area of a machine tool.

  As a conventional door lock control device for a machine tool, one described in Patent Document 1 below is known. This door lock control device compares the selection state by the selection means with the selection means for selecting the operation or release of the lock, the warning display means for displaying the selection contents, and the operation state of the warning display means, and if it is abnormal The lock is not released.

Japanese Patent No. 3329881

  In such a door lock control device for a machine tool, the operator visually determines whether the spindle has stopped and selects to release the lock, but in fact, there is a possibility of mistaking that the spindle is rotating due to inertia. For this reason, there is a possibility that the operator releases the lock, opens the door of the protective cover, enters the machining area, and comes into contact with the spindle or the tool, even though the spindle rotates by inertia.

  In view of this, the invention described in claim 1 makes it impossible to release the lock when the stop of the rotation of the spindle cannot be confirmed, and prevents the operator from entering the machining area while the spindle is rotating. An object of the present invention is to provide a door lock control device for a machine tool with improved safety.

  In order to achieve the above object, the invention described in claim 1 is directed to a lock mechanism capable of locking a door installed on a protective cover surrounding a processing area in a closed state, and to command the operation or release of the lock mechanism. A spindle rotation command is output to the lock mechanism control circuit and the spindle motor that drives the spindle in the machining area, and a spindle rotation command off signal is output to the lock mechanism control circuit when the spindle rotation command is turned off. A spindle control circuit, and a rotation detector that outputs a detection signal regarding whether the spindle is rotating or stopped to the spindle control circuit, and the spindle control circuit stops the detection signal. If it is determined that the main shaft rotation stop signal is output, the main shaft rotation stop signal is output to the lock mechanism control circuit, while the detection signal cannot be normally received. Then, an alarm signal is output to the lock mechanism control circuit, and the lock mechanism control circuit receives the spindle rotation command off signal and the spindle rotation stop signal and does not receive the alarm signal. The release mechanism can be instructed to release the lock mechanism.

  According to the present invention, when the detection signal cannot be normally received, the lock mechanism is released even if it is determined that the spindle rotation is not commanded and the rotation detector does not detect the rotation of the spindle. I will not forgive you. Therefore, even if it is erroneously determined that the rotation detector is broken due to disconnection or the like and the rotation of the main shaft is not detected, the lock mechanism can be made unreleasable, and the main shaft rotating by inertia while the rotation command is off Is prevented from being opened, and the safety can be improved.

  Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings as appropriate. In addition, the said form is not limited to the following example.

  FIG. 1 is a partial internal side view of a machine tool M according to the embodiment, and the machine tool M has a spindle X on which a tool L can be attached to a column C that can move on a bed B. In addition, a table T on which the workpiece W is placed is provided on the opposite side of the spindle X. The spindle X can freely advance and retract from the column C to the workpiece W side, and the tool L can be arranged at an arbitrary position above the table T in combination with the movement of the column C. A range in which the tool L can be arranged is a processing area A. Further, the machine tool M includes a protective cover V that surrounds the machining area A on the bed B, and the protective cover V has a door 1 that can be opened and closed at the front center of the machining area A. Furthermore, the machine tool M includes a control device 2 on the back side.

  FIG. 2 is a front view of the machine tool M with the door 1 and the like appearing. The door 1 has a left panel 3 and a right panel 4. First, the left panel 3 is slid onto the right panel 4 and then the left panel. 3 and the right panel 4 can be opened by sliding, and can be closed by sliding in the opposite direction. The left panel 3 and the right panel 4 each have a transparent plate-like window 6. A handle 8 is provided on the left front side of the left panel 3. A lock mechanism 10 that locks the door 1 in a closed state is provided on the left side of the door 1 opening or the left side (closed end) of the left panel 3. Here, as the lock mechanism 10, an electromagnetic type that uses a solenoid to engage and disengage the locking member with the closed end of the door 1 is used. The machine tool M is provided with an operation panel K electrically connected to the control device 2 on the right side of the front surface of the cover V. The operation panel K has a lock release key 12.

  As shown in FIG. 3, the control device 2 is electrically connected to the spindle motor S and the column C in the spindle X and a motor (not shown) that moves the spindle X, and the spindle control circuit 15, the lock mechanism Various circuits such as a control circuit 16 are provided.

  The spindle control circuit 15 outputs a spindle rotation command 20 to the spindle motor S of the spindle X to control the rotation speed of the spindle X, and when the spindle rotation command 20 is turned off, the spindle rotation command off signal 24 Is output to the lock mechanism control circuit 16. The spindle control circuit 15 is installed on the spindle X and is electrically connected to a rotation detector 28 that detects whether the spindle X is rotating and outputs a detection signal 26. When it is determined that the rotation is stopped, a spindle rotation stop signal 30 is output to the lock mechanism control circuit 16. The detection signal 26 is of a different type depending on whether the spindle X is rotating or stopped, and the spindle control circuit 15 determines that the rotation is stopped based on reception of the detection signal 26 relating to the type of rotation stop. The detection signal 26 may be a signal that transmits a signal having a content corresponding to the rotational speed, and the spindle control circuit 15 may determine the content of the detection signal 26 to determine the rotation stop.

  Further, the spindle control circuit 15 outputs an alarm signal 32 to the lock mechanism control circuit 16 when the detection signal 26 cannot be normally received. Here, a case where the detection signal 26 cannot be received and cannot be confirmed, and a case where the detection signal 26 can be received but does not indicate a predetermined type are assumed to be a case where the detection signal 26 cannot be received normally.

  The lock mechanism control circuit 16 activates or releases the lock mechanism 10 based on the presence / absence or content of the spindle rotation command off signal 24, the spindle rotation stop signal 30 and the alarm signal 32 that can be received from the spindle control circuit 15. Control is possible by command 40 or lock release command 42. That is, the lock mechanism control circuit 16 can output the lock release command 42 when receiving the spindle rotation command off signal 24 and the spindle rotation stop signal 30 and not receiving the alarm signal 32. In other words, even if the lock mechanism control circuit 16 receives the spindle rotation command off signal 24 and the spindle rotation stop signal 30, the lock mechanism control circuit 16 does not output the lock release command 42 if the alarm signal 32 is received. In this case, the lock mechanism control circuit 16 can output the lock release command 42 when the alarm signal 32 is turned off.

  FIG. 4 is a flowchart showing control contents in the lock mechanism control circuit 16. The lock mechanism control circuit 16 determines whether or not the spindle rotation command off signal 24 is received (step S1). If it has not been received (No), it is determined that the conditions relating to unlocking are not satisfied, and other processing is performed until the next lock mechanism control is performed (step S5). If it has been received (Yes), the process proceeds to step S2.

  In step S2, the lock mechanism control circuit 16 determines whether or not the spindle rotation stop signal 30 has been received. If not received (No), Step S5 is performed, and if received (Yes), the process proceeds to Step S3.

  In step S3, the lock mechanism control circuit 16 determines whether or not the alarm signal 32 is received. If the alarm signal 32 is received and the alarm signal 32 is on (No), Step S5 is performed. If the alarm signal 32 is not received and the alarm signal 32 is off (Yes), it is assumed that the condition for unlocking is satisfied and the lock is performed. The output of the unlock command 42 to the mechanism 10 is permitted (step S4).

  When the control device 2 detects an input to the lock release key 12 of the operation panel K in the case where the lock mechanism control circuit 16 establishes a condition for unlocking, the control device 2 sends a lock release command 42 to the lock mechanism control circuit 16. The output is commanded, and the lock mechanism 10 releases the lock based on the lock release command 42. On the other hand, if the lock mechanism control circuit 16 does not satisfy the conditions for unlocking, the control device 2 outputs an unlock command 42 to the lock mechanism control circuit 16 even if it receives an input to the unlock key 12. The lock mechanism 10 is not unlocked.

  In the door lock control device 1 of the machine tool M described above, the lock mechanism 10 that can lock the door 1 installed in the protective cover V surrounding the machining area A in a closed state, and the operation or release of the lock mechanism 10 are instructed. The spindle rotation command 20 is output to the lock mechanism control circuit 16 and the spindle motor S that drives the spindle X in the machining area A. When the spindle rotation command 20 is turned off, the spindle rotation command off signal 24 is sent to the lock mechanism control circuit. A spindle control circuit 15 that outputs to the spindle 16 and a rotation detector 28 that outputs a detection signal 26 regarding whether the spindle X is rotating or stopped to the spindle control circuit 15. When it is determined that the detection signal 26 indicates stop, the spindle rotation stop signal 30 is output to the lock mechanism control circuit 16 while the detection signal 26 is If it is determined that it cannot always be received, an alarm signal 32 is output to the lock mechanism control circuit 16, and the lock mechanism control circuit 16 has received the spindle rotation command off signal 24 and the spindle rotation stop signal 30, and the alarm. When the signal 32 is not received, a release command to the lock mechanism 10 is possible. Therefore, the spindle rotation command off signal 24 and the spindle rotation stop signal 30 are received, and a rotation command is issued to the spindle X. If the alarm signal 32 is received and the detection signal 26 from the rotation detector 28 is actually not normal even if the stop of the main shaft X is grasped by the detection signal 26 from the rotation detector 28, The lock mechanism 10 cannot be released. Accordingly, in the unlikely event that a failure such as a disconnection occurs between the rotation detector 28 or the spindle control circuit 15 and the detection signal 26 is not normal, the lock mechanism control circuit 16 indicates that the rotation is stopped for the detection signal 26. If it is erroneously determined and only the spindle rotation command off signal 24 is received, it is possible to prevent a situation in which the lock mechanism 10 can be released. Therefore, when the detection signal 26 is abnormal and the main shaft rotation command off signal 24 is generated, but the main shaft X is rotating due to inertia, the inertia rotation of the main shaft X is mistakenly regarded as being stopped and the lock release key 12 is erroneously viewed. Is allowed to open the door 1, so that a person who enters the machining area A from the door 1 unintentionally contacts the main spindle X during inertial rotation, cutting waste, liquid, etc. A situation where the door 1 unexpectedly jumps out can be prevented, and safety can be improved.

It is explanatory drawing of the machine tool which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the door lock control apparatus of the machine tool which concerns on this invention, or its periphery. It is a block diagram of a door lock control device of a machine tool concerning the present invention. It is a flowchart regarding the door lock control apparatus of the machine tool of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Door 10 Locking mechanism 15 Spindle control circuit 16 Locking mechanism control circuit 20 Spindle rotation command 24 Spindle rotation command OFF signal 26 Detection signal 28 Rotation detector 30 Spindle rotation stop signal 32 Alarm signal 42 Unlock command

Claims (1)

A locking mechanism capable of locking the door installed on the protective cover surrounding the processing area in a closed state;
A lock mechanism control circuit for commanding the operation or release of the lock mechanism;
A spindle control circuit that outputs a spindle rotation command to a spindle motor that drives the spindle in the machining area, and outputs a spindle rotation command off signal to the lock mechanism control circuit when the spindle rotation command is turned off;
A rotation detector that outputs a detection signal related to whether the spindle is rotating or stopped to the spindle control circuit;
When the spindle control circuit determines that the detection signal indicates a stop, the spindle control circuit outputs a spindle rotation stop signal to the lock mechanism control circuit, while determining that the detection signal cannot be received normally, an alarm A signal is output to the lock mechanism control circuit;
The lock mechanism control circuit receives the spindle rotation command off signal and the spindle rotation stop signal, and can receive a release command to the lock mechanism when the alarm signal is not received. A machine tool door lock control device.

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