JPH0546282B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electric motor control device during overload during cutting of a workpiece in a tenon removing machine having an automatic lifting and lowering function.

[Background of the invention]

1. In conventional mortising machines with automatic lifting and lowering functions, a clutch that uses spring pressure is installed in the power transmission mechanism between the electric motor _M2 for lifting and lowering the head and the screw shaft, which prevents overload from occurring while the head is lowering. At the same time, the power transmission is cut off to prevent a load exceeding a certain level from being applied to the main body, and the operation of the clutch is detected and the power to electric motors M ₁ and M ₂ is cut off, and the drive motor M ₂ is started to rotate in reverse for a short time. The vehicle was evacuated by climbing up the head section.

The causes of overload during tenoning are (1) when the cut piece of wood from the workpiece sinks under the head, restricting the downward movement, and (2) when the workpiece is hardwood. , when the motor has a large joint, or when the descending speed is too fast, the electric motor M ₁ may be in a restrained state, and then the descending operation may be in a restrained state. However, in the conventional method, the locked state can only be released in case (1), but in case (2), after the electric motor M ₁ becomes locked, a load above a certain level is applied to the main body, and the clutch is released. Since there is a time delay between detecting the operation of this clutch and cutting off the power to motors M ₁ and M ₂ , it is difficult to use when the workpiece is small or when the clamping force of the vise mechanism is weak. In FIG. 1, the workpiece is rotated clockwise (in the direction of arrow A) using the vise mechanism as a fulcrum. Alternatively, if the clamping force by the vice mechanism is strong enough, the entire vice mechanism clamping the workpiece is pushed back to the left (in the direction of arrow B) in FIG. 1. For this reason, excessive force is applied to the vertical and horizontal circular saws, causing problems such as chipping of the cutting edge of the circular saw, deformation of the circular saw itself, and deformation of the head parts that support the circular saw. It was hot.

Also, when both circular saw drive shafts become locked, the power to motors M ₁ and M ₂ is cut off and mortise processing is stopped midway, so in order to perform mortise processing again, It is necessary to re-grip the material in the vise mechanism and start the electric motors M ₁ and M ₂ , which poses a problem in that the efficiency of the tenon removal work is significantly reduced.

2. Even in the conventional tenon removal machine, a cut limit detector for limiting the cut range of the workpiece is provided below the head portion. However, during the tenoning operation, especially during the shading operation, the piece of wood that is being cut is cut off before the head reaches the lower limit position, slips under the head, and is detected by the cut limit detector. At this point, the hiding work has been completed, but it is determined that there is an abnormality, and the power to motors M ₁ and M ₂ is cut off. Furthermore, motor M ₂ is started to rotate in reverse for a short period of time, and the head is raised. He had evacuated. Therefore, it was necessary to raise the head portion, resulting in poor workability.

[Purpose of the invention]

The present invention has been made in view of the above, and has the following objects: (1) To prevent the rotation of the motors M ₁ and M ₂ by detecting in advance an overload condition that may be applied to the main body during mortising work. This is to control the drive and prevent deformation and damage to the main body.

(2) It is possible to detect an overload condition in advance and automatically control the rotational speed of the electric motor _M2 , thereby improving the time lost during mortising work.

[Summary of the invention]

The present invention provides the following features: (1) If an overload is applied to the main body regarding the lowering movement of the head part during tenon removal work,
(2) If an overload is applied to the main body due to the rotating operation of the circular saw, stop the descending of the head, and then move the head upward, and then lower it. Focusing on reducing the speed and starting the cutting operation again, we have developed detectors A and B, and an electric motor that output signals corresponding to the overload applied to the lowering drive system of the head and the load applied to the circular saw drive system.
Each of M ₁ and M ₂ is equipped with a drive circuit, a speed adjustment switch for supporting and controlling the rotational speed of electric motor M _2, and a phase control device, and receives output signals from detectors A and B.
The electrical relationship with the calculation circuit that calculates overload conditions and automatically controls the drive circuits of electric motors M ₁ and M ₂ has been devised, and a cutting limit detector is used to detect pieces of wood that are cut during shading work. The electrical relationship is devised so that when the head section is moved, the head section is retracted to a pre-designated return position.

[Embodiments of the invention]

An embodiment of the present invention will be described below. Fig. 1 is a side view showing the schematic structure of the tenon removing machine of the present invention;
The figure is an operation panel diagram.

In FIG. 1, a pair of vertical saws 5 and horizontal saws 6 are attached to a head section 4 guided by a column 3 that stands up from a base 2 that is equipped with a vice mechanism section 1 that holds a workpiece 26. Electric motor 7 that drives both of these circular saws
(hereinafter abbreviated as _M1 ) is equipped with a drive transmission mechanism (not shown). The number of screw shafts 8 is one or two.
It is made up of a book, is erected on the base 2 parallel to the column 3, and is fitted with screws so that the head part 4 can be raised and lowered. The upper ends of the column 3 and screw shaft 8 are supported by a bridge portion 9, and the screw shaft 8 is supported by a motor 10 disposed on the bridge shaft 9.
(hereinafter abbreviated as _M2 ) via a drive transmission mechanism (not shown). Therefore, by rotationally driving _M2 , the head section 4 can be moved up and down. The lower limit position of the lifting range of the head section 4 is determined by a lower limit detector 13 provided on the head section 4 using a bar provided on the base 2, and the upper limit position is determined using a bar 12 provided on the head section 4 provided on the bridge section 9. This is detected by the detector 14.

_The operation panel 15 shown in _{FIG .}
A raising switch 18 and a lowering switch 19 that instruct the raising and lowering of the head part 4, a speed adjustment switch 20 that can instruct the descending speed of the head part 4 in multiple stages, and a raising and returning position of the head part 4 that can be set in advance in multiple stages after the tenon removal work is completed. A return position adjustment switch 21 that can be adjusted is provided.

In the case of general tenoning work, first operate the operation switch 16 in the operation panel 15, _and then
is activated to rotate both the vertical saw 5 and the horizontal saw 6, and then lower the head section 4 at the speed instructed by the speed adjustment switch 20 to remove the workpiece held in the vice mechanism section 1. The material 26 is cut to the desired tenon size. After completing the tenoning process, bias 2
When the lower limit detector 13 installed on the descending head section ₄ detects _the bar _{11 placed} at The rotation is reversed and the head portion 4 is raised. The head portion 4 is raised from a position away from the bar 11 or the lower limit detector 13 to the return position specified by the return position adjustment switch 21, or from a position away from the bar 11 or the lower limit detector 13.
The bar 12 disposed at the upper limit detector 14 is raised to the position detected by the upper limit detector 14 and stopped.

However, during the mortising process, the following abnormal overload is assumed to occur on the descending head portion 4.

(1) The opening/closing dimensions and core movement dimensions of both circular saws 5 and 6 are incorrectly set for the clamping work of the workpiece 26 in the vise mechanism part 1 or the mortising dimension of the workpiece 26, A case where the workpiece 26 held by the vice mechanism part 1 is caught between the head parts 4.

(2) When a piece of tenon wood generated during the tenoning process is not removed and remains and gets caught between the head part 4 and the base 2 during the next tenoning process, and the descending movement is restricted.

(3) If the workpiece 26 is hardwood or has large knots, or if the speed adjustment switch 20 that instructs the descending speed is incorrectly set and tenon processing is performed, both circular saws 5 and 6 may The driving M ₁ becomes in a restrained state, and rotational force or return force acts on the workpiece 26 in the direction of arrow A or B as shown in FIG. When the body deforms or even when _M2 , which drives the head part downward, becomes restrained.

In order to prevent the above overload conditions, each overload condition is detected and the
It is necessary to control M ₁ and M ₂ and release the restraint state. As a means for this, in the case of (1) above, the head portion 4
A cut limit detector 25 is disposed on the lower side of the workpiece 26, and when the opening/closing dimensions and core movement positional relationship of each pair of circular saws 5, 6 are inappropriate with respect to the workpiece 26, When an attempt is made to process a length exceeding the set maximum tenon length, the depth of cut limit detector 25 detects the workpiece 26 while the head section 4 is descending, and the descending operation of the head section 4 is stopped. Raise and evacuate. In the case of (2), M ₂ of the vertical movement system of the head section 4, screw shaft 8
and an encoder 24 having a plurality of slit portions at appropriate locations in the power transmission mechanism (not shown), and a detector 49 for detecting the presence or absence of the slit portions of the encoder 24.
is wired, the pulse width of the pulse signal output from the detector 49 is measured, and when the pulse width exceeds a preset value, it is predicted that a restraint state will occur.
The lowering operation of the head section 4 is stopped and the situation is evacuated. The encoder 24 and the detector 49 constitute a detector A. In the case of (3), as in the case of (2), an encoder having a plurality of slits at appropriate locations in M ₁ of the drive system for both circular saws, the circular saws 5 and 6, and the power transmission mechanism (not shown) is used. 23 and a detector 48 for detecting the presence or absence of the slit portion of the encoder 23, the pulse width of the pulse signal output from the detector 48 is measured, and when the pulse width exceeds a preset pulse width, a restraint state is established. Foreseeing what would happen, M _1
M2 is stopped, and _M2 is reversed to raise and retract the head section 4. The encoder 23 and the detector 48 constitute a detector B. In the case of (3), if the circular saw drive system is predicted to be locked and the operation of the main body is stopped, the mortising process will be interrupted and the work efficiency will be reduced, so it is necessary to release the locked condition. After that, M ₁ and M ₂ are started again, the descending speed of the head section 4 is automatically adjusted as appropriate, and the tenon processing is continued.
Work efficiency should be improved.

The operation of the present invention will be explained below using the block circuit diagram shown in FIG.

In Figure 3, a normally open relay contact 27a is connected in series between the power line and _M1 , while the
Normally open relay contacts 28a, 29a, and triax 30 are connected in series between _M2 to enable forward and reverse rotation, and a phase control circuit 32 is connected between the power lines via the normally open relay contact 28a. There is. The phase control circuit 32 is input to the power supply line L and N terminals,
A DC power supply Vc is generated internally, and resistors 39 to 43 are connected in series and parallel between this Vc and N, and a switch 44
~47 open/close states specified in advance in multiple stages
A speed voltage Vf corresponding to the rotation speed of M ₂ , that is, the descending speed of the head section 4 is _generated , and the frequency signal detected by the speed detector 31 is converted into a direct current by a frequency/voltage converter (not shown). Convert it to voltage Va, compare the magnitude of Vf and Va, and find that Vf>Va
When , the conduction angle of the triax is increased and Vf<
When Va, the conduction angle of the triax 30 is controlled to be small, and the speed is controlled so that the rotational speed always corresponds to the speed voltage Vf.
When the normally open relay contact 27a closes, _M1 rotates, and both circular saws 5 and 6 rotate. When the normally open relay contact 28a closes and some of the switches 44 to 47 are closed, the specified speed voltage Vf is generated.
_M2 rotates forward and the head section descends at the indicated speed.
Furthermore, when the normally open relay contact 29a is closed, _M2 is reversed and the head portion 4 is raised.

Next, a circuit for controlling the opening and closing of the normally open relays 27a, 27a, 28a and the switches 44 to 47 will be described.

This circuit is composed of a microcomputer 33 having a CPU, RAM, ROM, input/output ports, clock generator, etc., and has input ports A ₀ -
Decoder 3 connected to A ₅ and output ports A ₆ and A ₇
A matrix is constructed with four open collector outputs Y ₀ , Y ₁ , Y ₂ , and Y ₃ , and the signals of each switch and each detector are read. SW1 is the operation switch 16, SW2
is stop switch 17, SW3 is rise switch 1
8. SW4 is the lower limit switch 19, S1 is the cutting limit detector 25, S3 is the upper limit detector 14, S4 is the lower limit detector 13, SP ₀ to SP ₅ are the speed adjustment switches 20.
The lowering speed of the head section ₄ can be set in multiple stages as shown in FIG. ₄ according to _the output signals of the notches SP ₀ to SP _{5 .} , v ₄ , v ₅
(v ₀ < v ₁ < v ₂ < v ₃ < v ₄ < v ₅ ) is set in advance by a program. P ₁ to _{P 4} are the contact points of each notch of the return position adjustment switch 21, and depending on the output signal of each notch of P ₁ to P ₄ , the return position is adjusted from the lower limit position of the head part 4 to the workpiece after the tenon removal is completed. Material 2
According to the processing dimensions of 6, as shown in Fig. 5, H ₁ ,
H ₂ , H ₃ , H ₄ (H ₁ <H ₂ <H ₃ <H ₄ ) are set in advance in the program. Microcomputer 33
The B ₀ and B ₁ input ports of the machine include an encoder 23 for detecting the rotation of the driving systems of both circular saws 5 and 6, a detector 48 for detecting the presence or absence of the slit portion of the encoder 23, and a detector 48 for detecting the presence or absence of the slit portion of the encoder 23, and An encoder 24 for detecting speed and a detector 49 for detecting the presence or absence of a slit portion of the encoder 24 are connected to each other. The output signals of these detection units 48 and 49 are periodic signals according to the rotational speed of both circular saws 5 and 6 and the lifting speed of the head unit 4, and the pulse width of this signal is measured by the microcomputer 33. As a result, overload states of both circular saws 5 and 6 and the lifting drive system can be detected simultaneously. Therefore, when these pulse widths exceed a preset pulse width, it is determined that some kind of overload has been applied to each drive system, and M ₁ and M ₂ may be controlled as described above.

The Co to C ₃ output ports of the microcomputer 33 are ports for instructing the opening and closing of switches 44 to 47 in the series/parallel circuit of resistors 39 to 43,
It is designed to close when the output signal is logic "1". _The logic signals of the output ports C ₀ to _{C 3} are programmed to correspond to preset machining speeds as shown in _{FIG .} Resistors 39 to 43 and switches 40 to 47 correspond to v ₃ , v ₄ , and v ₅
Depending on the combination of Vf ₀ , Vf ₁ , Vf ₂ , Vf ₃ , Vf ₄ ,
A speed voltage Vf of Vf ₅ , (Vf ₀ >Vf ₁ >Vf ₂ >Vf ₃ >Vf ₄ >Vf ₅ ) is generated.

The output ports D ₀ to _{D 3} of the microcomputer 33 are connected to the relay coils 27 to 29 and the buzzer 22 via amplifiers 35 to 38, and when the output port is theoretical "1", each relay coil 27 to 2
9 is energized, normally open relay contacts 27a, 27a,
28a is energized. Also, the buzzer 22 is energized and issues an alarm when necessary.

Next, the operation of the present invention will be explained.

The operator holds the workpiece 26 in the vise mechanism 1 as shown in FIG. 1, and then operates each switch on the operation panel 15. The microcomputer 33 sets the output ports A ₇ and A ₆ to logic “0, 0”.
and the open collector output of the decoder 34
Turn on Y ₀ and connect SW1 to input ports A ₀ to _{A 3} .
The operating status of SW3 is always read.

The worker turns down switch 19 for ink adjustment.
When (SW4) is turned on, input port A3 becomes logic "0", this logic "0" is sensed by microcomputer 33, output port D1 is set to logic " ₁ ", and relay coil 2 is output via amplifier 36.
8 and closes the normally open relay contact 28a,
The output port _C2 is set to theoretical "1", the switch 46 is closed, and the speed voltage Vf= _Vf3 is set to the phase control circuit 32.
The triax 30 is triggered to start rotating _M2 in the forward direction, and the head section 4 is lowered at a lowering speed of _v3 . When the head part 4 is lowered and the vertical saw 5 approaches the workpiece 26, the lowering switch 19 (SW
4), input port _A3 becomes logic "1", and this logic "1" is output to microcomputer 3.
3 and output ports C ₂ , D ₁ to logic “0”
The relay coil 28 is stopped from being energized, the normally open relay contact 28a is opened, the power to _M2 is cut off, and the lowering of the head section 4 is stopped.

In addition, when raising the head section 4, turn on the raising switch 18 (SW3), the input port _A2 becomes logic "0", this logic "1" is sensed by the microcomputer 33, and the output port _D2 becomes the logic state. "1", energizes the relay coil 29 via the amplifier 37, closes the normally open relay contact 29a,
Start _M2 in reverse rotation and raise the head. When the rising switch 18 (SW3) is turned OFF, the input port A2 becomes logic "1", which is sensed by the microcomputer 33, and the output port _D2 becomes logic "0".
Then, the excitation of the relay coil 29 is stopped, the normally open relay contact 29a is opened, the power to _M2 is cut off, and the lifting of the head section 4 is stopped.

Next, when performing tenon processing, switch the operation switch 1.
When 6 (SW1) is turned ON, the input port A ₀ becomes logic "0", which is detected by the microcomputer 33, and the period of this logic "0" is a preset time T.
(0.3 to 0.5 seconds) or more, execute tenon processing, set output port D ₀ to logic "1",
Via the amplifier 35, the relay coil 27 is excited, the normally open relay contact 27a is closed, _M1 is started to rotate, both circular saws 5 and 6 are rotated, and after a preset delay time _T1 has elapsed, the output port is opened. With A ₇ and A ₆ as theoretical "1, 0", turn on the output Y ₂ of the decoder 34, read which notch the speed adjustment switch 20 is at from the input ports A ₀ to A ₅ , and turn the output port D ₁ on. In addition to setting the logic to "1", output logic signals are input to the output ports _C0 to _C3 according to the state of each notch, as shown in FIG. 4, and the switch 44 is turned on.
47 is opened and closed, the speed voltage Vf is set to one of Vf ₀ to Vf ₅ , M ₂ is started to rotate forward, and the head portion 4 is lowered at a specified speed to perform mortising.

It is assumed that the main body will be in one of the three overload states mentioned above during the tenoning process, and the circuit operation in each case will be explained using FIG. 2.

1 In the case of (1) above, while the head section 4 is lowering, the output ports _A7A6 of the microcomputer ₃₃ are set to theoretical "0, 1", the _Y1 output of the decoder 34 is turned ON, and the depth of cut is limited. The logic state of the input port A ₀ that inputs the operating signal of the detector 25 (S ₁ ) is read periodically, and if logic "0" is detected, the output ports C ₀ to C ₃ and D ₀ are immediately read. D ₁
is set to logic "0" and relay coils 27, 28
Stops the excitation of normally open relay contacts 27a, 28
Open A, cut off the power to M ₁ and M ₂ , and after the preset delay time T ₂ , set the output port D ₂ to logic "1".
As a result, the relay coil 29 is energized, the normally open relay contact 29a is closed, _M2 is started to rotate in reverse, and the head portion 4 is raised and retracted. This upward retraction is set in the program to the return position instructed by the return position adjustment switch 21 or until the upper limit detector 14 (S ₃ ) is activated.

2 In the case of (2) above, while the head section 4 is descending,
Input the pulse signal output from the detector 49 to the input port _B1 of the microcomputer 33,
The period of logic "0" and "1" of this pulse signal is read at fixed time intervals, and when the read logic state does not change more than the preset number of readings N ₁ , some kind of overload occurs in the lowering operation of the head section 4. Immediately, output port
By setting C ₀ to C ₃ and D ₀ and D ₁ to logic “0”, the same control as in the case 1 above is performed, and only the rising operation is performed for a preset time T ₅ , and the head section 4
The program is set to raise and retreat.

3 In the case of (3) above, when the head part 4 is lowered and the workpiece 26 is being tenoned by both circular saws 5 and 6, a pulse signal outputted from the detector 48 is sent to the input port of the microcomputer 33. B ₀ , read the period of logic "0" and "1" of this pulse signal at fixed time intervals, and when the read logic state does not change more than the preset number of readings N ₂ , both circular saws 5 and 6 It is determined that some kind of overload has occurred on the output port, and the output port is immediately
C ₀ to C ₃ and D ₀ , D ₁ are set to “0”, the excitation of the relay coils 27 and 28 is stopped, the normally open relay contacts 27 a and 28 a are opened, and the power to M ₁ and M ₂ is cut off. After the set delay time _T2 , the output port _D2 is set to logic "1" for a preset time _T5 , and the relay coil 29 is energized, the normally open relay contact 29a is closed, _M2 is started in reverse rotation, and the head is turned on. Part 4 is slightly raised and retracted. If the operation of the main body is stopped in this state, the tenon removal process will be interrupted, which will greatly reduce work efficiency.
Therefore, in order to perform the tenoning process again, the output ports D ₀ and D ₁ are set to logic "1", the relay coils 27 and 28 are energized, and the normally open relay contact 2
7a and 28a, and the speed instructed by the speed adjustment switch 20 or the instructed speed is decreased by one step, and a logic signal is output from the output ports _C0 to _C3 , and the switches 44 to 47 are activated. The machine opens and closes the machine, rotates both circular saws 5 and 6, lowers the head part 4 again, and continues lowering the tenon. If an overload occurs again in the same way as the tenon removal process continues, the above-mentioned operation is repeated.

Also, when the indicated speed was _V3 , or when an overload was detected and the descending speed was slowed down one step at a time, an overload occurred in both circular saws 5 and 6 during mortising at the descending speed of _V3 . In this case, the period of logic "0" and "1" of the pulse signal output from the detector 48 is read at fixed time intervals, and the read logic state is read for a preset number of times N ₃ (N ₃ < N ₂ ), in order to set the descending speed to the set value v _2.5 between v ₃ and v ₂ , change the logic states of output ports C ₀ to C ₃ as shown in FIG. 4, and switch 44
The opening/closing state of ~47 is changed to continue the tenon removal process.

As described in 1 to 3 above, M ₁ and M ₂ can be controlled appropriately by predicting the restraint state while detecting the unique overload state in the mortising machine.

Furthermore, in cases 1 and 2 above, after detecting the overload condition and completing the control operation of M ₁ and M ₂ , the output port
D ₃ is intermittently set to logic "1" several times, and amplifier 38
The buzzer 22 is operated via the alarm to issue an alarm to notify the user that an overload condition has occurred in the main body.

While the workpiece 26 is being tenoned, that is, the head portion 4 is being lowered, the output ports A ₇ and A ₆ of the microcomputer 33 are set to logic "0, 1" and the decoder 3 is
4's _Y1 output is turned ON, and the logic state of the input port _A3 , which inputs the operation signal of the falling detector 13 ( _S4 ), is read periodically, and when logic "0" is detected,
That is, when the bar 11 provided on the base 2 is detected by the lower limit detector (S ₄ ) provided on the head portion 4, immediately
The outputs of output ports C ₀ to C ₃ and D ₀ , D ₁ are set to logic “0”
, stop excitation of relay coils 27 and 28,
Open the normally open relay contacts 27a, 28a, M ₁ , M ₂
Cut off the power to. After that, after a preset delay time _T2 has elapsed, the output port _D2 is set to logic "1", the relay coil 29 is energized, the normally open relay contact 29a is closed, _M2 is started to rotate in reverse, and the head section 4 is turned on.
to rise.

The head section 4 starts to rise and the bar leaves the lower limit detector 13 (S ₄ ), that is, the output port A ₃
After the microcomputer 33 senses that the logic of
The designated return position is reached when the pulse signals of the detector 49 input to B ₁ are counted and the return position data (H ₁ to _{H 4} ) corresponding to the state of each notch of the return position adjustment switch 21 is counted in advance. It is determined that the output port _D2 has been set to logic "0", the relay coil 29 is deenergized, the normally open relay contact 29a is opened, and the power to _M2 is cut off. After that, after the preset delay time _T3 has elapsed, the output port D1 is set to logic " ₁ ", and the output ports _C0 to _C3 are set to the descending speed.
v ₃ , opens and closes the relay coil 28 and switches 44 to 47, starts rotating M ₂ in the forward direction for a preset time T ₄ , and raises the head section 4 by inertia. Reduce and stop.

In addition, in the tenon removal work, there is a unique work called shading work, and as shown in Figure 6, 1
Process as shown in (a) the first time, and process as shown in (b) the second time.

A piece of wood C cut by this hidden work
However, the cutting tool crawls under the descending head section 4, and before the head section 4 reaches the lower limit position, the depth of cut limit detector 2
Detected by 5. However, by the time the piece of wood C has been cut, the shielding work has already been completed, so
When the cut limit detector 25 detects a piece of wood C, the M ₁ , M It is designed to control rotation and stop of ₂ .

FIG. 5 shows program data set in the ROM of the microcomputer 33 regarding the control of the present invention, where memory addresses N to N+6 are output data of output ports C ₀ to _{C 3} , which are descending speed data;
N+7 to N+9 are data used when measuring the pulse width of the output pulse signals of the detectors 48 and 49 that detect the overload state of M ₁ and M ₂ , and N+10 to N+
17 is set with data used when counting the upward return distance of the head portion 4 after the tenon processing.

FIG. 7 is a flowchart showing the operation of the present invention during the tenon removal work.

In the figure, three examples A, B, and C are shown as flowcharts in the case where an overload occurs after the rotation of _M1 is detected.

A is the speed indicated by the speed adjustment switch 20, and M ₂
This shows the case when starting .

B shows the case where _M2 is activated by decreasing the speed indicated by the speed adjustment switch 20 one step at a time.

C is when the speed indicated by the speed adjustment switch 20 is _V3 , or when the speed is decreased and the speed is _V3 , the rotational speed of _M2 is switched to _V2.5 , which is between the indicated speeds ₃ and ₂ . It shows.

〔Effect of the invention〕

According to the present invention, in order to detect an overload condition that may occur during mortise processing in a tenon cutter having an automatic lifting function, a cut limit detector is provided on the lower side of the head part, and a lowering drive system of the head part is installed. An overload detector for the circular saw drive system and an overload detector for the circular saw drive system are installed, and the output signals of each detector are read.If an overload condition occurs during mortising, the descending drive electric motor _M2 ,
Since the electric motor _M1 for driving the circular saw is appropriately controlled so as not to reach a restricted state, deformation and damage to the main body can be prevented, and safe tenon removal work can be performed.

In addition, in the event that the circular saw drive system becomes overloaded, the lowering speed of the head section can be adjusted in multiple stages. The rotation control of M ₁ and M ₂ and the speed of M ₂ are automatically controlled to reduce the speed,
Since the tenon removal work can be restarted, the decrease in work efficiency can be greatly improved.

Furthermore, even when the cut limit detector detects a piece of wood that is produced by the shading work that is typical of mortising work, it will rise to the normal return position and stop in the same way as when the lower limit detector operates. Therefore, the setup time for the next tenoning work can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the schematic configuration of the tenon removing machine according to the present invention, FIG. 2 is a diagram of the operation panel,
Fig. 3 is a block circuit diagram of the present invention, Fig. 4 is a chart showing the descending speed adjustment switch and output logic signal, Fig. 5 is a chart showing program data, Fig. 6 is a diagram explaining the hidden work, Fig. 7 is a flowchart. In the figure, 4 is a head part, 5 is a vertical saw, 6 is a horizontal saw, 7 is an electric motor M ₁ , 10 is an electric motor M ₂ , 11,
12 is a bar, 13 is an upper limit detector, 14 is a lower limit detector, 15 is an operation panel, 16 is an operation switch, 1
8 is a rise switch, 19 is a fall switch, 20 is a speed adjustment switch, 21 is a return position adjustment switch, 22 is a buzzer, 23 and 24 are encoders, 2
5 is a cut limit detector, 26 is a workpiece, 27-2
9 is a relay coil, 27a to 29a are normally open relay contacts, 30 is a triax, 31 is a speed detector,
32 is a phase control circuit, 33 is a microcomputer, 34 is a decoder, 35 to 38 are amplifiers, 39
~43 is a resistor, 44~47 is a switch, 48,4
9 is a detector.

Claims (1)

[Scope of Claims] 1. A reversible electric motor M ₂ guided by a column installed upright on a base equipped with a vise mechanism for clamping a workpiece.
In a mortising machine that has a structure in which the head part is raised and lowered by a vertical and horizontal saw, and an electric motor _M1 that drives both vertical and horizontal circular saws is installed in the head part, the upper and lower limits of the raising and lowering range of the head part are set. An upper limit detector, a lower limit detector that detects the position, and a cutting limit detector that limits the range that can be cut by both circular saws are installed below the head, and the load on the drive system that drives the head up and down is installed. A detector A outputs a signal according to the state, a detector B outputs a signal according to the load state of the drive system that drives both circular saws, and a detector B instructs to start and stop the electric motors M ₁ and M ₂ . An operation switch, a speed adjustment switch for instructing and adjusting the rotation speed of electric motor M ₂ , a phase control device for controlling the rotation speed of electric motor M ₂ , and an instruction for raising and returning the head section after tenon processing. A return position adjustment switch is provided for adjustment, and receives the output signal of each of the detectors and the output signal of each switch to start, stop, and control the electric motors M ₁ and M ₂ .
and an electric motor control device in a tenon removal machine having an arithmetic circuit for automatically adjusting the rotational speed of electric motor _M2 . 2. When the workpiece comes into contact with the depth of cut limit detector while the head is lowering, an alarm will be issued if the power to motors M ₁ and M ₂ is cut off, and then motor M ₂ is started in reverse and the head is moved up and evacuated. 2. The electric motor control device for a mortise machine according to claim 1, further comprising an arithmetic circuit for controlling the electric motor so as to generate the electric motor. 3. During tenon processing, when an overload condition occurs in the head lifting drive system, the overload condition is determined based on the output signal of the detector A, and after cutting off the power to the electric motors M ₁ and M ₂ , Start electric motor _M2 in reverse,
2. The motor control device for a mortise machine according to claim 1, further comprising a calculation circuit for controlling to issue an alarm when the head portion is raised and retracted. 4. During the tenoning process, when an overload condition occurs in both circular saw drive systems, the overload condition is determined based on the output signal of the detector B, and after cutting off the power to the electric motors M ₁ and M ₂ , After starting the electric motor _M2 in reverse and moving the head up and away, start the electric motor _M1 again,
2. The electric motor control device for a mortise machine according to claim 1, further comprising an arithmetic circuit for controlling the rotational speed of the electric motor _M2 to be started at the same speed or at a reduced speed so as to restart the tenoning process. 5. During tenoning work, when a thinly cut piece of wood is detected by the cut limit detector, especially during shading work, a calculation is performed to control the wood to be raised and retreated to the return position indicated by the return position adjustment switch. A motor control device for a mortise machine according to claim 1, further comprising a circuit. 6. As a means for detecting the load condition of the circular saw drive system and the head lifting drive system, the rotational speed of the rotating members of each drive system may be detected magnetically or optically and changed into an electrical signal, or a rotating 5. The tenon removal machine according to claim 1, further comprising: an encoder having a plurality of slits attached to the member; and detectors A and B for detecting the presence or absence of the slits and converting the detected presence into an electric signal. Electric motor control device. 7. As a method of detecting the load state of the double saw drive system and the head lifting drive system, the load current of the motor _M1 and the motor _M2 is detected magnetically or by connecting a resistor,
5. The motor control device for a mortise machine according to claim 1, further comprising a detector A or B for converting the voltage into voltage. 8. The tenon remover according to claim 1 or 5, further comprising an arithmetic circuit that receives the output signal of the detector A for detecting the load condition of the head lifting drive system according to claim 6 and counts the lifting distance of the head section. Electric motor control device for machines. 9. A reference value for the overload condition of the double circular saw drive system according to claim 4, which is set in advance in a plurality of stages, and the overload condition is determined only when the specified speed is specified by the speed adjustment switch. The overload condition is determined based on the output signal of the detector B, and the motors are switched off without cutting off the power to the motors M ₁ and M ₂ .
Claim 1 further comprising an arithmetic circuit for controlling the load state of the electric motor _M1 by reducing the rotational speed of the motor _M2 .
A motor control device in the described tenon removal machine.