JPH0219210Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an elevation control device for a mortise machine having an automatic elevation function.

[Background of the idea]

In conventional mortise machines with automatic lifting and lowering functions,
When the head is raised and retracted after completing the tenoning work on the workpiece, the raising time of the head is manually adjusted to raise and stop the head at an arbitrary position.
However, when an AC commutator motor or the like is used as the lifting motor for raising and lowering the head, mechanical losses such as fluctuations in the power supply voltage supplied to the lifting motor and sliding resistance of the lifting power transmission mechanism may cause Since the rotational speed of the motor changes and the rising speed of the head fluctuates, there is a problem in that the stopping time of the head varies greatly depending on the setting of the rising time. This problem is caused by the fact that if the head stops at a lower position than the operator desires, the saw blade may hit the workpiece when positioning the workpiece in the vise mechanism, making the work difficult. Or, conversely, if the head stops at a higher position than the operator desires, the gap between the saw blade and the workpiece will increase.
There was a problem where it was difficult to match the ink lines of the saw.

[Purpose of invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, improve the positioning accuracy of raising and retracting the head and stopping it after completing the tenoning work on the workpiece by a tenon machine with automatic lifting, and improve work efficiency. It's about improving.

[Summary of the invention] This invention calculates the distance the head rises and retreats until it stops after the completion of the tenoning work.
This design was devised based on the idea that the inertia of the head could be prevented from rising by turning off the power to the lifting motor when it reaches a predetermined lifting distance, and then turning on the power to reverse the lifting motor for a short period of time. be.

[Example of idea]

An embodiment of the present invention will be described. FIG. 1 is a schematic side view of the tenon removal machine of the present invention, and FIG. 2 is a block circuit diagram showing a control circuit diagram of the lifting control device.

A column 3 is provided vertically on a base 2 equipped with a vice mechanism 1 for positioning a workpiece 20.

The head 4, which is driven up and down along the column 3, is equipped with a vertical saw blade 5, a horizontal saw blade 6, and a saw motor 7 for driving the saw blades 5 and 6. The screw shaft 8 is vertically installed on the base 2 parallel to the column 3, and is screwed into the base 2 so that the head 4 can be moved up and down.

The upper ends of the column 3 and the screw shaft 8 are supported by a bridge 9, and the screw shaft 8 is connected to a lifting motor 10 disposed on the bridge 9. Therefore,
The head 4 moves up and down by rotating the lifting motor 10. The lower and upper limits of the vertical range of the head 4 are determined by a protruding member 11 provided at the lower part of the head 4 and a protruding member 12 provided at the upper part of the head 4.
Then, the protruding member 11 is detected by a detector 13 provided on the base 2, and the protruding member 12 is detected by a detector 14 provided on the bridge 9.

An encoder 15 having a plurality of slits is arranged near the upper end of the screw shaft 8, and a detector 16 is arranged near the encoder 15 to detect the slits.
is provided.

Generally, when performing tenoning work, use Bridge 9.
The saw motor 7 and the lifting motor 10 are operated by operating the operation switch 17 provided at the saw blade 5 and 6, and the head 4 is lowered while rotating the saw blades 5 and 6.
A workpiece 20 held by the vice mechanism 1 is cut into a predetermined tenon size. When the tenoning work is completed and the protruding member 11 at the bottom of the head 4 reaches the position of the detector 13, the saw motor 7 and the lifting motor 1 are turned off.
0 is stopped, and after a preset period of time has elapsed, the rotation of the lifting motor 10 is reversed to raise the head 4. After the head 4 shifts to upward drive, the encoder 1
5 slits are detected by the detector 16, and counted by a counter 29, which will be described later. When the count reaches the value specified by the changeover switch 19, the operation of the lifting motor 10 is stopped. After that, by turning on the power for a short time and reversing the lifting motor 10,
The rise of the head 4 due to inertia is suppressed and stopped, and the tenon removal work is completed.

Next, the details of the control of the saw motor 7 and the lifting motor 10 of the mortising machine will be explained with reference to the block circuit diagram shown in FIG. This block circuit diagram shows operation switch 17, detector 13, detector 14, detector 1
6 and the changeover switch 19 as input signals to operate the saw motor 7 and the lifting motor 10,
This controls the stoppage.

In FIG. 2, the normally open relay contact 21a is connected to the power line of the saw motor 7, and the lifting motor 1
Normally open relay contacts 22a, 23a on the 0 power line
are connected. When the normally open relay contact 22a is closed, the elevating motor 10 rotates normally and the head 4 is lowered, and when the normally open relay contact 23a is closed, the elevating motor 10 is reversely rotated and the head 4 is raised. Relay coils of these normally open relay contacts 21a, 22a, 23a correspond to 21, 22, 23, respectively.

When the operation switch 17 is operated, its output is inverted from logic "0" to "1", and this rising signal causes the set reset 24 to be set, and the Q output signal is inverted from logic "0" to "1". In response to this logic "1" output, the relay coil 21 via the amplifier 33 and the coil 22 via the OR gate 25 and amplifier 34 are excited, and the normally open relay contacts 21a and 22a are closed. Therefore, power is supplied to the saw motor 7 and the lifting motor 10, and the saw motor 7 and the lifting motor 10 rotate, and while the saw blades 5 and 6 rotate, the screw shaft 8 is rotated, and the head 4 is rotated. lower it.

When the head 4 descends and the detector 13 detects the protruding member 11 at the bottom of the head 4, its output signal is inverted from logic "0" to "1". This logic "1" signal resets the Q output signal of the set reset 24, deenergizes the relay coil 21 and the relay coil 22, and normally opens the relay contacts 21a and 22.
a opens, cutting off the power to the saw motor 7 and the lifting motor 10. On the other hand, the timer 26 detects the inversion of the output signal of the detector 13 from logic "0" to "1", emits a signal having a preset time T ₁ pulse width, and sets the reset 27 after the time T ₁ . , its Q output signal is inverted from logic "0" to "1". This logic "1" signal causes amplifier 3
5, the relay coil 23 is energized, the normally open relay contact 23a is closed, the lifting motor 10 is reversed, and the head 4 continues to rise. Therefore, when the head 4 shifts from descending to ascending, the shock applied to the main body can be reduced by shifting to the ascending state after the elapse of time _T1 .

Immediately after the head 4 moves up, the detector 13
When the output signal of the head 4 is in the state of logic "1" and this logic "1" signal is inverted to "0", that is, when the protruding member 11 at the bottom of the head 4 leaves the position of the detector 13, the rise occurs. An AND gate 2 receives the inverted output signal of the detector 13 and the Q output signal of the set reset 27 to count the distance.
8 regulates the operation of the counter 29. From the time when the AND gate 28 is inverted from logic "0" to "1", the counter 29 is enabled to perform counting operation,
The pulse signals from the detector 16 continue to be counted.

On the other hand, when the count value of the counter 29 reaches the count value corresponding to the lifting stop position of the head 4 instructed and set by the changeover switch 19, the counter 29
A pulse signal of logic "1" is generated. This signal resets the Q output signal of the set-reset 27 via the OR gate 30, deenergizes the relay coil 23 via the amplifier 35, opens the normally open relay contact 23a, and cuts off the power to the lifting motor 10.

Furthermore, the output of the counter 29 is
Since it is connected to the timer 31 through 0, it detects the pulse signal of the counter 29, emits a signal having a pulse width of a preset time T ₂ , and outputs a signal having a pulse width of a preset time T _2.
After that, the timer 32 is further activated to generate a signal having a pulse width of a preset time _T3 . The relay coil 22 is excited by the signal having the pulse width time T ₃ via the OR gate 25 and the amplifier 34, the normally open relay contact 22a is closed for the time T ₃ , and the lifting motor 10 is reversed. Therefore, when the head 4 reaches the lifting stop position specified by the changeover switch 19 and stops the head 4, the head 4 is lowered for the time _T3 to reduce the distance that the head 4 moves up due to inertia. can be stopped.

Since the detector 14 is input to the OR gate 30, the head 4 can be raised to the upper limit position of the detection range and then stopped, and in this case, the control circuit operates as described above.

In FIG. 2, resets 24 and 27, OR gate 25, amplifiers 34 and 35, relay coils 22 and 23, normally open relay contacts 22a and 23a
is the rotation direction switching circuit of the lifting motor 10,
The reset circuit 27 and the AND gate 28 constitute a counting control circuit for the counter 29.
Although the stop switch 18 is not shown in FIG. 2, even if the stop switch 18 is operated while the head 4 is being raised or lowered, in order to stop the head 4 at any position within the raising or lowering range, the detection It is sufficient to connect the output signals of the switch 13 and the stop switch 18 to the R terminal of the set/reset 24 via an OR gate, and to connect the stop switch 18 to the OR gate 30.

[Effect of idea]

According to the present invention, when the head shifts to the upward drive state, after the operation of the lower limit detector is restored, the upward distance of the head is counted, and when the upward stop position desired by the operator is reached, the count value is reached. Since the power to the lifting motor is cut off and then the lifting motor is reversed for a short period of time, the accuracy of the lifting and stopping position of the head is improved, and workability can be greatly improved compared to conventional mortising machines.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a block circuit diagram explaining the operation of the tenon removing machine of the present invention. In the figure, 2 is a base, 3 is a column, 4 is a head, 5 is a vertical saw blade, 6 is a horizontal saw blade, 7 is a saw motor, 10 is a lifting motor, 11 and 12 are protruding members, 13 and 14 is a detector.

Claims (1)

[Claim for Utility Model Registration] In a tenon machine in which a head equipped with a saw blade moves up and down along a column vertically installed on a base, there is a protruding member at the upper and lower parts of the head, and detection for detecting the protruding member. a saw motor that drives the saw blade and a lifting motor that raises and lowers the head when the head is driven downward and the detector located below the head operates. After the specified time, turn off the power to
The elevating motor is reversely driven to raise the head, and as the head is driven upward, from the time when the protruding member leaves the detector of the detection means at the lower part of the head,
A control circuit that counts the upward drive of the head is operated, and when the head reaches a position preset in the control circuit or when the head rises to a position where the detection means on the upper part of the head operates, the operation of the head is started. A lift control device for a tenon removal machine, which is characterized by being stopped.