JP2694482B2 - Core drill automatic feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic core drill feeder used for drilling a concrete structure for piping during heating and cooling work or electrical work, and more specifically to a bit for drilling at the tip. The present invention relates to a core drill automatic feed device for forming a cylindrical hollow by applying a core drill equipped with the above to a surface to be drilled and rotating at high speed.

[0002]

2. Description of the Related Art When a core drill automatic feeder is mounted on a drilling machine to perform drilling, the following are required for the automatic feeder. (A) Enable soft start (at the start,
Since the load “0” is input, the duty factor
And the overload is applied to the drill drive motor of the drilling machine). (B) To be able to set a reference value that can cope with a resistance load depending on the mounting conditions of the drilling machine other than the drilling work. (C) In order to stabilize the load of the drill drive motor, the error amplification rate must be as low as possible. (D) If a foreign object such as a reinforcing bar is hit during the drilling operation, a sudden load is applied. (E) After the load is released, there is a time lag between when the load release signal is transmitted from the control motor of the automatic feeder to the drill drive motor, but a gentle start can be made in this case as well. Therefore, it is necessary to automatically change the reference voltage to be compared with the input voltage to the automatic feeder.

(Prior Art) Conventionally, as a drilling machine of this type, a drill bit 3
02 is supported on the rail 311 on which the rack 310 is formed, the mounting member 312 provided at the tip of the rail 311 is fixed to the perforated surface, and the handle 313 is manually operated to move the core drill 303 to the rack of the rail 311. Drilling machine 300 that pierces while advancing along 310
(Fig. 1; Japanese Utility Model Application Laid-Open No. 63-133917).
issue). Further, in the case of piercing while automatically feeding the piercing machine 300, the piercing operation is performed while controlling the gear box 301 for automatic feeding mounted on the piercing machine 300 by the control box 320 incorporating a transformer (FIG. 2).
reference).

[0004]

However, the conventional drilling machine has the following problems. That is, for example, when forming a hollow in reinforced concrete, when the bit at the tip of the drill reaches the reinforcing bar, a sudden load is applied to the motor for driving the drill, and an extreme load fluctuation occurs in the concrete part and the reinforcing bar part. For this reason, in feedback control performed simply by measuring the load of the drill drive motor and calculating the deviation from the reference voltage set by the operator, the drill drive motor is overloaded at the restart and the load is released. When a load release signal is transmitted from the load control motor to the drill drive motor when the load release signal is transmitted, the operation becomes unstable, resulting in extremely poor work efficiency and hunting.
Further, there is a possibility that the motor for drill driving and the bit may be damaged; and in the above-mentioned feedback control, unless the error amplification rate of the error amplification means is increased, the drilling of small diameter holes from the cutting of foreign matters such as reinforcing bars is performed. Although it may not be able to cope with a wide range of load fluctuations, hunting is generally increased when the error amplification factor is increased, and the load fluctuation of the drill drive motor also increases. When drilling holes with unknown depth, the drilling work is usually performed by setting an inappropriate initial value (state) that is not accurate.
Even if the drilling depth is known, it is difficult for the operator to know whether or not the drilling has been completed when the drilling work proceeded; the amount of work required for drilling cannot be accurately known. , Work efficiency is poor when many hollows of the same depth are drilled; when performing automatic drilling, a control box for controlling the automatic feed gearbox is usually required, but this control box is generally heavy. In addition, since it is bulky, it is not suitable for drilling work at high places, and it is difficult to perform automatic drilling in narrow places and water pools, which is not versatile.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to enable automatic feeding of a core drill in a drilling machine and the properties of the drilling surface (hardness, rebar, etc.). The object is to provide a core drill automatic feeding device in which hunting is unlikely to occur even when an extreme load change occurs, by automatically adjusting the feed rate according to the presence or absence of foreign matter, etc.).

Another object of the present invention is to automatically feed the core drill by which the motor for rotating the drill of the drill automatically stops in an emergency and protects the motor for rotating the drill and the bit to prolong the life of the drill. To provide a device.

[0007]

An automatic core drill feeder according to the present invention is an automatic core drill feeder which is mounted on a drilling machine and automatically feeds a core drill of the drilling machine having a drill bit at a tip end thereof. At the time of drilling, load detecting means for detecting a load of a drill driving motor for driving a core drill and outputting a signal corresponding to the detected load, and a load state of the drill driving motor based on a signal output from the load detecting means. When the load state of the drill driving motor is in an allowable load state other than the overload state and the underload state, the reference voltage of the error amplifying means is lowered and the error output is increased when the reinforcing bar is cut. To reduce the load on the drill drive motor by shortening the input pulse width to the control motor and slowing down the feed of the control motor. At the end of rebar cutting, raise the reference voltage of the error amplifying means, reduce the error output, increase the input pulse width to the control motor, speed up the control motor feed, increase the load on the drill drive motor, and increase the drill drive load. A reference voltage adjustment output means connected to the load state determination means for automatically adjusting and outputting a reference voltage in response to a load change of a motor; a voltage value corresponding to a load of a drill driving motor; and the reference voltage adjustment output. An error amplifying means for comparing and collating with a reference voltage value output from the means, amplifying and outputting the error signal, and applying a triangular wave sent from a triangular wave generating circuit to the error signal sent from the error amplifying means, Pulse width modulation circuit for converting the signal to a signal having a pulse width and outputting the signal to a motor control means, a drill driving motor and a control mode. Controls, and outputs a signal for stopping the motor drill drive when the load of the drill drive motor is overloaded or under load,
When a pulse signal is sent from the pulse width modulation circuit via the reference voltage adjustment output means, motor control means for ON / OFF controlling the current flowing through the control motor according to the pulse width output by the pulse width modulation circuit, And a control motor that is driven according to a control signal output from the motor control means, is connected to the drill driving motor, and brakes the drill driving motor.

[0008]

[Operation] When the automatic feeder configured as described above is started, the feed speed is automatically adjusted according to the properties of the drilling surface, and if the drill driving motor is suddenly loaded, the Decelerating the control motor and then gradually restarting it, and setting the optimum reference voltage value so that an appropriate load is applied to the drill drive motor, and operating the drill drive motor with a constant power. Accordingly, the voltage value is controlled to set the optimum duty factor value.

Further, when the load of the drill driving motor is excessive, the drill driving motor of the drilling machine is automatically stopped.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 3 is a perspective view of an automatic core drill feeder according to the present invention, FIG. 4 is an enlarged perspective view showing a front panel on which each operation unit is arranged in the automatic core drill feeder, and FIG. FIG. 6 is a perspective view showing a conventional drilling machine, FIG. 6 is a perspective view showing a state in which a core drill automatic feeder is mounted on the drilling machine, FIG. 7 is a functional block diagram showing a basic configuration of the core drill automatic feeder, and FIG. FIG. 3 is a circuit configuration diagram specifically showing each element of FIG.

In these figures, A indicates an automatic core drill feeder according to the present invention, which is attached to a punching machine 250 and has a drilling bit 253 at the tip thereof.
The automatic feed of the core drill 252 is performed (see FIGS. 5 and 6).

Reference numeral 2 is a drill driving motor provided in the drilling machine 250, and drives a core drill 252 having a bit 253.

Reference numeral 19 denotes a control motor arranged in the automatic feeding device, which is gear-connected to the drill driving motor 2 and controls the drill driving motor 2 in response to a control signal output from a motor control means 18 described later. Control.

Reference numeral 3 is a load detecting means for detecting the load of the drill driving motor 2 at the time of drilling and outputting a signal according to the detected load. 4 is an AC voltage output from the load detecting means 3 as a DC voltage. A rectifying circuit for conversion, 5 is a smoothing circuit connected to the rectifying circuit 4, and 6 is a circuit for converting a voltage value output from the smoothing circuit 5 into a predetermined voltage level in response to a load fluctuation of the first motor 2. The level conversion circuits are shown respectively.

Reference numeral 7 denotes a load state determination means, which is based on the output signal of the load detection means 3 provided through the level conversion circuit 6 so that the load state of the drill driving motor 2 is an overload state, an underload state, or an allowable load state. In order to determine which of the (appropriate) load state (set value state or less than set value state), the multi-stage comparators 8, 9, 10 are used (see FIG. 8). The load signal of the drill driving motor 2 is sent to the load state judging means 7 through the level conversion circuit 6.

Of these, reference numeral 8 denotes an overload detecting section, which detects the signal when the load of the drill driving motor 2 is overloaded. Reference numeral 9 denotes an underload detection unit,
The signal is detected when the load of the drill driving motor 2 is too small. Numeral 10 denotes an allowable load detecting unit constituted by five stages of comparators 10a, 10b, 10c, 10d and 10e, wherein the load of the drill driving motor 2 is within an allowable (proper) range other than an overload and an underload. The signal is detected when the load is.

Reference numeral 11 denotes a reference voltage adjustment output means, which is connected to the load state determination means 7 and the load state of the drill driving motor 2 is in an allowable (appropriate) load state other than an overload state and an underload state. At times, the reference voltage is automatically adjusted (shifted) and output according to the load variation of the drill driving motor 2. During the drilling operation, the load of the drill driving motor 2 varies as described above depending on the properties of the target object. In the present invention, when the load is increased, the voltage of the capacitor 40 shown in FIG. 8 is reduced to obtain a low reference voltage. That is, when the load of the drill driving motor 2 is an appropriate load, the reference voltage adjustment output means 1
The voltage across the capacitor 40, which constitutes 1, is held by the amplifier 41. This reference voltage adjustment output means 11
Du given to the control motor 19 by the operation of
Match the width of the ty Factor to a proper load of 0-100%.

Reference numeral 15 denotes an error amplifying means, which compares the voltage value corresponding to the load of the drill driving motor 2 with the reference voltage value output from the reference voltage adjustment output circuit 11 and outputs the error signal. Is amplified and output.

Reference numeral 16 is a triangular wave generating circuit, and 17 is a triangular wave generating circuit 1 for the error signal sent from the error amplifying means 15.
6 is a pulse width modulation circuit that applies a triangular wave sent from 6, converts an error signal into a signal having a pulse width, and outputs the converted signal.

Reference numeral 18 denotes a motor control means, which controls the drill driving motor 2 and the control motor 19. The overload detection section 8 or the underload detection section 9
When a pulse signal is sent from the pulse-width modulating circuit 17, a current for stopping the drill driving motor 2 is output.
ON / OFF control in accordance with the pulse width output from. When a signal is sent from the underload detection unit 9 to the motor control means 18, the control motor 19 stops.
The motor control means 18 includes a power supply circuit 150 described later.
Is connected. Therefore, compared to the case where a transformer is used for the power supply unit, the automatic drilling device can be made compact and lightweight, and the drilling work can be efficiently performed even in a narrow place or a high place where there is no place to place the transformer. Can be. The control motor 19 is connected to counter means 190 which will be described later. Therefore, it is possible to accurately know the amount of work at the time of drilling by digital display, it is easy to confirm the completion of the drilling work, and the work amount required for drilling (drilling amount) can be set in advance. This is convenient when a large number of holes are drilled.

Now, the operation means and display means arranged on the front panel 50 in the box B of the automatic feeder A will be described with reference to FIGS. 3 and 4.

Reference numeral 51 denotes a changeover switch for switching the control motor 19 between forward (F) and reverse (R), which is constituted by a toggle switch. The mounting portion of the automatic feeder A may change depending on the type of the drilling machine 250. In this case, since the rotation direction of the control motor 19 may be reversed, the switch 51 is operated to change the rotation of the control motor 19.

[0023] 52 denotes a display unit for digitally displaying the drilling of two digits which are set, are constituted by light-emitting diodes. Reference numeral 53 denotes an operator for setting a desired two-digit count number (perforation work amount).
C. D. It is composed of a code switch. 5
Reference numeral 4 denotes a setting push button switch for displaying (SET) the count number (drilling work amount) selected by the operation element 53 on the display unit 52 by pressing, and 55 cancels the display on the display unit 52 (RESET). ) To display “0” is shown. 58 is a push button switch for starting the control motor 19, 59
Indicates a push button switch for stopping the control motor 19.

Reference numeral 60 denotes a switch for selecting automatic stop or manual stop, which is composed of a toggle switch. When tilted to the manual side, the drill drive motor is manually stopped. When the drill is tilted to the automatic side, the drill driving motor 2 and the control motor 19 stop interlockingly when the drilling operation is completed, when an underload is detected, and when an overload is detected. Thus, when the worker leaves the site during the drilling operation, the switch is tilted to the automatic side. Reference numeral 61 denotes an up / down switch for switching between forward (upward degree: UP) and reverse (remaining amount: DOWN) of the count in the counter means 190;
It consists of a toggle switch. Reference numeral 62 denotes a knob for selecting a working speed (either weak, medium, or strong) for the drilling work according to the power supply used, and is constituted by a rotary switch. When the power source of a drilling machine is required to be the power source of a building (drilling place), when the same power source is used for lighting and other work, the drill drive motor is overloaded during the drilling work, If a larger current flows, the circuit may be interrupted by the breaker of the power supply box. To avoid this, it is appropriate to set the knob 62 to "weak" at first.

Reference numerals 57A, 57B and 57C denote load display lamps which are turned on depending on the amount of current of the drill driving motor 2.
These load indicating lamps 57A, 57B, 57C are light-emitting diodes (for example, the load indicating lamp 57A is an "orange" light emitting diode, and the load indicating lamp 57B is a "blue" light emitting diode) to indicate the load state of the drill driving motor 2. The diode and the load indicating lamp 57C are constituted by “red” light emitting diodes). And the load display lamp 5
When only 7A is turned on, it indicates that the load of the drill driving motor 2 is smaller than the assumed load. When the load indicating lamps 57A and 57B are turned on, the load of the drill driving motor 2 takes a value substantially close to the assumed load, indicating that an appropriate drilling operation is being performed. When all of the load display lamps 57A, 57B, and 57C are lit and displayed, it indicates that the vehicle is in an overload state.

Reference numeral 70 designates a clutch connecting / disconnecting knob, which connects the feed shaft 251 (see FIG. 5) of the drill driving motor 2 to the bearing port 49 (see FIGS. 3 and 4) of the automatic feeder A,
The control motor 19 controls the rotation of the drill driving motor 2.
Disengage the clutch to tell. 71A and 71B are a pair of stays used when the automatic feeder A is mounted on the punch 250.

(Operating Procedure of Automatic Feeding Device A) Next, the operating procedure of the automatic feeding device A will be briefly described. First, with the switch 60 tilted to the manual side,
Start cutting the REIT. After the rotation of the drill driving motor 2 is stabilized, the knob 70
Operate to engage the clutch. The switch 60 is tilted to the automatic side. The start push button switch 58 is pushed. The setting push button switch 54 is pushed. Set with the control 53
The displayed numbers are displayed on the display unit 52. In this case, count
When finishing the work with "0", set the switch 61 to the reverse side.
Lean on. Or more Perform the operation.

The automatic feeder A has the power supply circuit 15 as described above.
However, since the diamond of the bit 253 is worn and slips after cutting the reinforcing bar for a long time, it is necessary to provide a large pushing force even when the cut is stopped. Therefore, as a practical power supply circuit for this automatic feeder, the control motor 1
Even if 9 is locked, it is required to maintain a constant torque without burning the control motor 19 for a certain time.

The power supply circuit 150 will be described with reference to FIG. The power supply circuit 150 is connected to the rectifier circuit 150A for converting an AC power supply into a DC power supply, and the rectified DC voltage is connected to the rectifier circuit 150A to control the motor 19.
And a voltage control circuit 150B for controlling the input voltage to an appropriate input voltage so that the control motor 19 can withstand a load when the control motor 19 stops in an excessive load state and a constant load. Current control circuit 150C for controlling so as to hold
And a smoothing capacitor 158 which is connected to the load current control circuit 150C and smoothes the output of the load current control circuit 150C.

Of these, the rectifier circuit 150A is formed by a bridge rectifier circuit, and the voltage control circuit 150 is used.
B includes a Zener diode 156, a resistor 155 for controlling a current flowing through the Zener diode 156, and Darlington-connected transistors 151 and 152. Further, the load current control circuit 150C includes a transistor 153 for current detection and a resistor 157. 159 is a diode for preventing backflow. Thus, the current flowing into the smoothing capacitor 158 is regulated by the diode 159, and the voltage decreases as the load increases.

Further, the automatic feeder A sets the working amount (drilling depth) at the time of drilling as described above, and counts (measures) accurately.
Counter means 190 for performing the operation. This counter means is required to: When the power is turned on or when the bit 253 bites into the rebar, a sudden excessive load is applied, and a current several times the rated current flows to the drill driving motor 2 instantaneously. For this reason, the counter means having the same power supply as the drill drive motor can sufficiently withstand large voltage fluctuations and noise. Intense vibration may occur depending on how the bit 253 hits the reinforcing bar. Therefore, even when the count sensor constituting the counting means is at the threshold value, no count error occurs. The desired amount of drilling work is arbitrarily set, for example, in numerical values in units of cm, and in the process of performing the drilling work, the drilling work must always be completed when the drilling work for the numerical value is performed. The countdown or countup of the arbitrary set number n → 0 or 0 → n is performed accurately so that the work progress can be confirmed.

The counting means 190 will be described with reference to FIG. The counting means 190 includes a sensor slit disk 203 connected to the feed shaft 251 of the drill drive motor 2, and a first signal for generating a signal for preparing a drilling work amount count when the slit disk 201 starts rotating.
And a second photosensor 203 that counts the amount of rotation of the feed shaft 251 of the drill driving motor 2 to measure the drilling depth and generates a count signal. A latch circuit 205 for latching signals generated by the first photosensor 202 and the second photosensor 203, a work amount setting operator 53 for performing an operation of setting and storing a desired arbitrary number of drilling work amounts, An up-down counter connected to the count sensor 200 via a latch circuit 205 and outputting an up or down count signal when an output signal of the latch circuit 205 and a signal sent by operating the operation element 53 are input. 207 and when the output signal from the up / down counter 207 becomes “0”, Constant and and a 0 output judging pulse generating circuit 208 which generates a pulse of a predetermined width.

Of these, the first photosensor 202
And the second photosensor 203 are constituted by transmission type photointerrupters. The count sensor 200 detects the amount of rotation of the feed shaft (rotary shaft) 251 of the drill driving motor 2. Reference numeral 204 denotes the first
2 shows a waveform shaping circuit for shaping the waveforms of the photo sensor 202 and the second photo sensor 203, which is formed by a monostable multi-circuit. Reference numeral 211 denotes a power supply backup circuit that backs up a voltage of the DC 10V power supply 312 due to the influence of the drill driving motor 2 because the voltage fluctuation occurs. 209 is B.I. C. D. to 7 segmen
t.

The counter means 190 is constructed as described above, and when the set work amount is reached, a signal notifying the end of the work is sent to the motor control means 18. Also, the bit 253 hits a reinforcing bar or the like, and the drill driving motor 2
When the load fluctuation of the drill becomes severe, the drill driving motor 2
And the counter means 190 share the same power source,
The counter means 190 is likely to generate noise due to voltage fluctuation. Therefore, after a lapse of a predetermined time after the power is turned on, for example, 0.
It is turned on after 5 seconds so that the memory will not be erased even when the power is suddenly dropped, and the influence of noise at power-on can be avoided as much as possible. Further, when the bit 253 of the drill 252 hits a reinforcing bar or the like, the sensor slit disk 201 constituting the count sensor 200 is subjected to severe vibration and is likely to make a count error (there may be reverse rotation). Therefore, as described above, the slit disk 201 for the sensor is provided with a space, and the first photosensor 202 and the second photosensor 203 are provided.
2 photo sensors are arranged, the first photo sensor 202 latches the output, and the second photo sensor 203 outputs the count.

(Operation of Automatic Feeding Device) Next, the operation of the automatic feeding device A will be described (see FIGS. 9 to 12). Front panel 50 of automatic feeder A
When the automatic / manual changeover switch 60 (see FIG. 4) is tilted to the automatic side, the drill driving motor 2 starts rotating. After the rotation of the drill driving motor 2 is stabilized, the start push button switch 58 arranged on the front panel 50 is pressed, and the start signal is transmitted to the latch circuit 20.
(See FIG. 8), the latch circuit 20 is latched in the ON state, and the motor control means 18 controls the control motor 19.
And a signal for starting the drill driving motor 2 is transmitted. In this state, the bit 253 of the punch 250 can be fed to the punching surface. Bit 25 to the drilling surface
3 starts, a load current flows through the drill drive motor 2.

In the state shown in FIGS. 4 and 8, the front panel 5
0 is located at the "weak" position, and the load current of the drill drive motor 2 is set to C.O. T.
Sampling is performed by a current sensor (not shown). Then, the output voltage of the smoothing circuit 5 is sent to the level conversion circuit 6 and the error amplifier 15. The error amplifier 15 amplifies the error between the reference voltage and the voltage when the current of the drill drive motor is sampled, and sends the amplified signal to the pulse width modulation circuit 17 to correct the load on the drill drive motor 2. You. If the amplification factor is large, the responsiveness is improved. However, if there is a sudden and large load change, hunting is caused and the drill driving motor 2 and the bit 253 are damaged. For this reason, in order to adapt to such a load variation, the reference voltage of the error amplifying means 15 is lowered, for example, when cutting a reinforcing bar, to increase the error output. That is, when the reinforcing bar is cut, the load applied to the bit 253 is particularly large. Therefore, the greatly amplified error output causes the pulse width modulation circuit 17 to shorten the input pulse width to the control motor 19 and delay the feeding of the control motor 19. Then, the load on the drill driving motor 2 (bit 253) is reduced. When the rebar cutting is completed and the load on the drill driving motor 2 (bit 253) is reduced, the reference voltage of the error amplifying means 15 is increased to reduce the error output, and the input pulse width to the control motor 19 is widened. Speed up feeding (when the load state of the drill driving motor is in an allowable load state other than an overload state or an underload state, when the reinforcing bar is cut, the error amplifying means 15 is used.
, The error output is increased, the error output is increased, the input pulse width to the control motor 19 is shortened, the feed of the control motor 19 is slowed, and the load on the motor for driving the drill is reduced. The reference voltage of the means 15 is increased, the error output is reduced, the input pulse width to the control motor 19 is widened, the feeding of the control motor 19 is accelerated, and the load on the drill driving motor is increased. Automatically adjusts and outputs the reference voltage according to the fluctuation. ). This processing is performed by the reference voltage adjustment output means 11.

In the embodiment, the load condition judging means 7 is composed of nine-stage comparators as described above, and the first-stage comparator 9 contributes to detect an undercurrent value at the work end operation. The comparator 8 at the stage contributes to detect an excessive current value when the drill driving motor is locked. For this purpose, the level conversion circuit 6 stores the sampling value within the range of 1 to 9 stages.

Now, when the speed setting knob 62 is set to the "weak" position, the output of the comparator 10a in the third stage becomes "L" and the output of the comparators in the fourth and higher stages becomes "H". Then, the "orange" and "blue" light emitting diodes 57A and 57B arranged on the front panel 50 are turned on. When the bit 253 does not hit the reinforcing bar, the voltage of the capacitor 40 is high, and the reference voltage of the error amplifying means 15 is high accordingly. In the state of FIG. 10, when the input waveform of the control motor is a 'at the beginning, the duty factor
Is at 70%. When it hits the rebar, the current of the drill drive motor 2 sharply shifts to the b and c line segments and becomes a high sampling voltage. At this time, the outputs of the comparators 10b and 10c at the fourth and fifth stages are output. It becomes "L", and the capacitor 40 is discharged rapidly, and correction is made so that the error amplification of the error amplifier 15 increases. Further, in FIG.
After the input waveform of the control motor shifts from b ′ to c ′, a pulse having a waveform d ′ is output to the control motor 19 until the cutting of the rebar ends.

When the cutting of the reinforcing bar is completed, the current for driving the drill is reduced from the point b in FIG. The error output of the error amplifying means 15 expands the input waveform of the control motor to c 'by amplifying the previously given reference voltage, but the drill drive motor current value is insufficient at point c. At this time, the output of the comparator 10d becomes "H", and the capacitor 40
Then, the reference voltage of the error amplifier 15 is increased until the input waveform of the control motor reaches the point c ′ → e ′ (FIG. 9). At this time, if the amplification factor of the error amplifying means 15 is increased, the input waveform c 'reaches e' earlier,
There is a time error during transmission from the control motor 19 through the gears to the feed shaft 251 of the drill drive motor 2 → the bit 253 → the drill drive motor 2, and the feed rail 254 has a large resistance change due to the mounting angle and the like. Therefore, if the amplification rate is fixed, hunting occurs,
Further, the fuse is blown and the feeding speed becomes insufficient. Therefore, the correction time of t1 (FIG. 9) is considered. Also, depending on the contact angle of the rebar, the drill drive motor 2
May be locked. At this time, the output of the comparator 8 becomes “L”, and the latch circuit 20 is turned off.
The motor control means 18 and the relay circuit 21 are turned off.
T3 in FIG. 12 is a short time. Fig. 11
Since the current of the drill driving motor decreases as shown in the waveform diagram shown in FIG. 7, the output of the comparator 9 becomes "H". With this voltage, the capacitor 32 is charged for a certain period of time (t2 in FIG. 11) through which the work completion can be confirmed through the resistor 31 and sent to the latch circuit 20 through the inverter 33 to stop the drill driving motor 2.

(Operation of Power Supply Circuit) Further, the operation of the power supply circuit 150 will be described (FIG. 14).
reference). Bridge rectifier circuit 1
When rectified at 50 A, the waveform of the voltage at point P in FIG.
(A) shown in FIG. The motor maximum input voltage is set as the Zener diode voltage via the Zener diode limiting resistor 155. When this voltage is applied to the voltage control circuit 150B, the transistor 151 is turned on when the Zener voltage is higher than the Q point voltage. Q point voltage is 158
Is smoothed. The Q point voltage is determined by the load of the connected control motor 19. Here, when the control motor 19 is locked, the voltage that the control motor 19 can withstand for a certain time and the voltage that can maintain a certain torque at that time are 55 V, and the transistor 151
The maximum current flowing at the time of N is set to 1.3 A, and a current control circuit of 1.3 A is formed by the resistor 157 and the transistor 153. FIG. 14C shows the case where the load on the control motor 19 is small and the Q point potential is 98 V, the intermediate load is when the Q point potential is 85 V, and the control motor 19 is locked and the maximum load is when the Q point potential is 55 V. Voltage control circuit 1
It shows each conduction angle of 50B. Q point voltage is 98
In the case of V, a portion higher than 98 V, that is, a conduction angle of 44 to 1
Between 36 °, 37-143 ° at 85V and 23-157 ° at 55V, transistor 151
Is turned on. Since the supply current to the capacitor 158 is limited, when the load on the control motor 19 increases, the supply voltage to the control motor 19 decreases. Thus, the control motor 19 is protected from burnout, and the loss of the voltage control circuit 150B is reduced.
In this regard, in the case of the method of directly inputting the current from the rectifier circuit to the smoothing capacitor, if the load current increases, the input current of the capacitor also increases, and the input voltage of the control motor is supplied without decreasing. When the driving motor is locked, an excessive current flows, which easily causes burnout of the power transformer and burnout of the drill driving motor. Also, since the load on the control transistor can be reduced, drilling work can be performed without the need for a heavy transformer as in the past, and the drilling device required for drilling work can be reduced in weight and size, and can be used in high places and narrow places. Automatic drilling can be performed extremely easily even in a place where the working conditions are poor.

(Operation of Counter Means) The operation of the counter means 190 will be described (FIG. 16).
And FIG. 17). When the slit disk 201 for the sensor rotates, there is a wide difference in rotation from 10 rotations / second to 2 rotations / hour depending on working conditions. In particular, at 2 revolutions / hour, intense vibration occurs in the forward and backward directions, so that when the threshold value of the slit of the slit disk 201 overlaps the slit of the first photosensor 202, the vibration is relatively long (5 to 5). The first photosensor 202 and the second photosensor 203 generate a large number of pulses over about 10 minutes). Therefore, first, the latch circuit 205 is latched by the first pulse emitted from the second photosensor 203.
Now, when the slit of the slit disk 201 is applied to the first photosensor 202, the R input of the latch circuit 205 is
The pulse having the waveform shown in FIG. 6 is generated for a long time. At this time, the input S is at the "H" input, the output Q is latched at "L" at the first pulse, and does not change until the S input becomes "L" thereafter. Although the Q output is input to the up / down counter 207, counting is performed at the rising edge of the input signal, so that the next count is prepared when the input becomes "L". When the slit of the slit disk 201 is applied to the second photosensor 203, a large number of pulses are generated.
The waveform is first shaped into a fixed width by the waveform shaping circuit 204 and input to the SR latch circuit 205. At this time, the R input of the SR latch circuit 205 is an "H" input, and when an "L" signal is sent to S, the output Q is latched at "H" and does not change even if the S input changes thereafter. When the output Q changes to "H", the up / down counter 207 operates at the rising edge.
As described above, the first photosensor 202 and the second photosensor 2
The combination of 03 and the SR latch circuit 205 enables stable counting even if the slit disk 201 vibrates violently. Further, when the thickness of the concrete to be drilled is known or when drilling holes for embedding columns such as fences, it is necessary to set an arbitrary work amount. In this case, the operator 206 is operated, and a signal indicating that the number is an arbitrary number is sent to the up / down counter 207. Set the up / down switch 61 to DOWN and count D
Perform OWN. The O output determination pulse generation circuit 208 determines that the count has reached "0", generates a pulse of a constant width, sends the output to the motor control means 18, and stops the work. Further, the work amount can be known by setting the up / down switch 61 to UP and performing the UP count from "0". The power supply backup circuit 211 compensates for voltage fluctuations when the work motor is overloaded.

[0042]

The present invention is configured as described above and has the following effects. The feed rate can be automatically adjusted according to the properties of the perforated surface (hardness, presence or absence of foreign matter such as reinforcing bars, etc.), and an automatic core drill feeder that does not easily cause hunting even when an extreme load change occurs can be obtained. . When the bit of the core drill hits the reinforcing bar etc. and a sudden load is applied to the motor for driving the drill, the control motor is decelerated rapidly, and then restarted gradually, and it is optimal to apply the appropriate load to the motor for driving the drill. Set the reference voltage value and operate the drill drive motor with constant power, and control the voltage value according to the load to optimize the D
Since the UTY value is set, continuous smooth work is possible. In an emergency, the drill rotation motor of the drilling machine is automatically stopped, so that the drill driving motor and the bit can be protected to extend the life of the drilling machine.

[Brief description of the drawings]

FIG. 1 is a front view showing a conventional punching machine.

FIG. 2 is a perspective view showing a usage state of a conventional punching machine.

FIG. 3 is a perspective view of an automatic core drill feeder according to the present invention.

FIG. 4 is an enlarged perspective view showing a front panel on which respective operation parts of the automatic core drill feeder are provided.

FIG. 5 is a perspective view showing a conventional punching machine equipped with an automatic core drill feeder.

FIG. 6 is a perspective view showing a state in which a core drill automatic feeding device is attached to a punching machine.

FIG. 7 is a functional block diagram showing a basic configuration of an automatic core drill feeder.

FIG. 8 is a circuit configuration diagram showing each element of the automatic core drill feeder.

FIG. 9 is a diagram showing changes in the load current of the drill driving motor and the duty factor of the control motor when shifting from cutting the reinforcing bars to cutting only the concrete.

FIG. 10 is a diagram showing a change in load current of a drill driving motor and a change in Duty Factor of a control motor when shifting from concrete cutting to reinforcing bar cutting.

FIG. 11 is a diagram showing a change in load current of a drill driving motor and a change in a capacitor 32 at the end of drilling.

FIG. 12 is a diagram showing a change in load current of a drill driving motor and a change in output voltage of a comparator 8 in an overload state.

FIG. 13 is a circuit diagram showing components of a power supply circuit in the automatic core drill feeder.

FIG. 14 is a diagram illustrating a relationship between a P-point voltage and a Q-point voltage of a power supply circuit and a conduction angle of a transistor Tr1.

FIG. 15 is a functional block diagram showing a basic configuration of a counter means in the automatic core drill feeder.

FIG. 16 is a circuit diagram showing a signal flow when the first photo sensor constituting the counter means prepares for counting, and a waveform diagram showing input and output of the latch circuit at that time.

FIG. 17 is a functional block diagram showing a main configuration of a counter means, an output of the first photosensor when the second photosensor performs counting, an output of the second photosensor, and a latch circuit at that time. FIG. 3 is a waveform diagram showing input / output of the multiplexor.

[Explanation of symbols]

 A core drill automatic feeding device 2 drill driving motor 3 load detection means 4 rectifying circuit 5 smoothing circuit 6 level conversion circuit 7 load state determination means 8 excessive load detection unit 9 excessive load detection unit 10 allowable load detection unit 11 reference voltage adjustment output unit 15 error amplification means 16 triangular wave generation circuit 17 pulse width modulation circuit 18 motor control means 19 control motor

Claims (1)

(57) [Claims] 1. A core drill automatic feeding device which is mounted on a drilling machine and automatically feeds a core drill of a drilling machine equipped with a drilling bit at its tip end, wherein a load of a drill driving motor for driving the core drill is provided at the time of drilling. Load detection means (3) for detecting and outputting a signal according to the detected load, and load state determination means (3) for determining the load state of the drill driving motor based on the signal output from the load detection means (3) ( 7) And, when the load state of the drill driving motor is in the allowable load state other than the overload state and the underload state, the rebar cutting
Sometimes the reference voltage of the error amplifying means (15) is lowered and error output
To increase the input pulse to the control motor (19).
To reduce the feed width of the control motor (19).
Slow down to reduce the load on the drill drive motor
On the other hand, at the end of cutting the rebar, the error amplification means (15) is used as a base.
Control motor by increasing reference voltage and reducing error output
Control motor with wider input pulse width to (19)
(19) Speeding up the feed and loading the drill drive motor
To increase the load fluctuation of the drill drive motor.
Automatically adjusts and outputs the reference voltage corresponding to
Reference voltage adjustment output means connected to the state determination means (7)
(11) and the voltage value corresponding to the load of the drill driving motor and the reference voltage value output from the reference voltage adjustment output means (11) are compared and collated, and the error amplification means for amplifying and outputting the error signal. (15) and the error signal sent from the error amplifying means (15) is given a triangular wave sent from the triangular wave generating circuit (16), the error signal is converted into a signal having a pulse width, and the motor control means (18) To control the pulse width modulation circuit (17), the drill driving motor and the control motor (19), and to stop the drill driving motor when the load of the drill driving motor is excessive load or under load. and outputs, to the control motor (19) when the pulse signal from said pulse width modulation circuit (17) via the reference voltage adjusting output means (11) is sent Current
To the pulse width output from the pulse width modulation circuit (17).
Motor control means (18) for ON / OFF control according to
And a control motor (19) which is driven according to a control signal output from the motor control means (18), is connected to a drill driving motor, and brakes the drill driving motor. apparatus.