JPS59124507A - Drilling machine - Google Patents

Abstract

PURPOSE:To prevent a drill from damage, by detecting a load, changed in accordance with cutting resistance, of a driving motor so that a feed of the drill is stopped when the load in a preset level in the first stage is detected while the drill is stopped when the load in an excessive level in the second stage is detected. CONSTITUTION:If a driving motor 3' and a feed motor 4 are rotated by turning on a power supply switch 6 and a control switch 14, cutting is started by an electric drill. If a load of the motor 3' is increased by an increase of cutting resistance during the cutting, a potential difference between both ends of a resistor 15 is increased, and DC voltage generated in accordance with the load is output through a transformer 16 and a full-wave rectifier 17. If this voltage exceeds the Zener voltage, a relay 23 is turned on through a constant voltage diode 22, and a contact 24B of a relay 24 is opened, thus stopping the feed motor 4. And then the feed motor 4 is restarted by a decrease of the load, and if the load is again further increased, a constant voltage diode 29 is electrified, and a relay 12 is turned off, thus stopping the motor 3'.

Description

[Detailed description of the invention] Fixing means to the workpiece, for example, an electromagnetic base at the bottom, 1k
For example, a drilling machine equipped with an electric drill metal fitting having an annular cutting tool on the front side generates a large torque compared to a conventional drilling machine of this type equipped with a twist drill, so an abnormally large load is placed on the cutting tool. As a result, it could not be ruled out that accidents such as damage to the blade or burnout of the motor of the electric drill would occur. Therefore, since it is difficult to reduce the above-mentioned problem since handling such a drilling machine requires skill, an improvement measure has been desired. - In view of the fact that, for example, a drilling machine equipped with an annular cutter requires some skill in handling, the present invention enables even beginners to easily handle it, and also prevents breakage of the drilling tool and electric drill. This is related to a drilling machine developed with the aim of preventing motor burnout.It detects the magnitude of the electric drill motor's load, which fluctuates according to changes in cutting resistance, and adjusts the load to the level set in the first stage. When this is detected, all feeds of the electric drill are automatically stopped to reduce the load, and then, when the reduction in load is detected, the feed of the electric drill is restarted, and the excessive load is eliminated in the second stage. The third feature is that the electric drill is automatically stopped when detected.

The present invention will be explained below based on embodiments shown in the drawings.

FIG. 1 is a perspective view of a drilling machine embodying the present invention, in which 1 is a frame, and 2 is a frame installed at the bottom of the frame 1.
M base, 3 is an electric drill installed on the front part of the frame 1 so that it can be raised and lowered manually, and also electrically, 4 is a feed motor of the electric drill 3, and 5 is an arbor of the electric drill 3. The operating circuit, which is the main part of the present invention, is built into the frame 7. Figure 2 shows a block diagram of the maintenance circuit. The operating circuit No. 4 has first and second detecting sections for detecting the load of the electric drill 3 as a change in voltage, and both have 3.4 ON-OFF times wJ'liil''.

FIG. 3 shows an example of an operation circuit, in which the AC unit has an operation switch for the electromagnetic base 2 and a start switch 6 that also serves as an operation switch for the electric drill 3 and feeder motor 4; 0N- of electric drill 3 and feed motor 4
The OFF circuit has a start/stop circuit for the electric drill 3, a start/stop circuit for the feed motor 4, and a switching circuit for both operating circuits. First, the operating circuit for the electric drill 3 will be explained. Full-wave rectifier 7 that performs full-wave rectification of the AC voltage of
, a smoothing circuit connected to the output side of the rectifier 7 and configured with a capacitor 8, resistors 9 and 10, and a capacitor 11; and a first smoothing circuit connected to the output side of the smoothing/181 circuit. When the relay is activated, the AC circuit is closed at the contacts 12' of the relay 12, and the drive motor 3' of the electric drill 3 is rotated.

Next, the operation circuit of the feed 9 motor 4 will be explained.
The operating circuit operates when the contact 12' of the first DC relay 12 is closed, the first AC relay 13 is activated by opening the relay contact 12', and one contact 13- of the AC relay 13 is operated. 1, a feed motor 4 and a manual switch 14 connected in series.

The first detection part of the cutting resistance of the annular cutter 5 consists of a resistor 15 installed in series with the drive motor 3' of the electric drill 3, a transformer 6, and a full-wave rectifier 17, and detects the terminal voltage of the resistor 15. Then, the detected voltage is between the resistors 18 and 9 and 20.
It is applied to the first DC relay 23 from both ends of the capacitor 21 through the first diode 22, and then applied to the first DC relay 23 through the resistor 15.
When the value of the terminal voltage reaches a voltage corresponding to the smaller first stage of the preset loads for the electric drill 3, the first diode 22 is turned on,
The second DC relay 23 is moved one bit, the contact 23' of the relay 23 is closed, the second AC relay 24 is driven, and the power circuit of the feed motor 4 is cut off by the contact 24' of the relay 24. The rotation of the feed motor 4 is stopped, and the entire load on the drive motor 3' of the electric drill 3 is reduced by stopping the feed motor 4.

The second detection unit for the cutting resistance of the annular cutter 5 is the full-wave rectifier 1.
The gate of the silicon control element 31 is connected to one terminal of the voltage dividing resistor 25, 26° 27, the capacitor 28, the second diode 29, and the capacitor 30 provided at the output end of the control element group. , the cathode of the silicon control element 31 is connected to the other terminal of the capacitor 30,
The anode is a smoothing circuit resistor 9,100 of the full wave rectifier 7.
When the terminal voltage of the resistor 15 connected to the junction point reaches a voltage corresponding to the second stage set higher than the first stage, the diode 29 and the silicon control element 31 turn O.
N, the human power of the first DC relay 12 is short-circuited,
The contact 12' of the blood flow relay 12 is opened and the electric drill 3
The drive motor 3' is configured to stop.

32 is a changeover switch that selects different load control levels depending on whether a relatively small-diameter annular cutter is used or a larger diameter annular cutter, and a variable resistor 19.19
When the voltage applied to the capacitor 21 becomes larger than the Zener voltage of the constant voltage diode 22 due to an increase in load, the constant voltage diode 22 becomes
N, current flows through the coil of the second DC relay 23 and it becomes activated, the contacts 23' of the relay 23 close, and the second tributary relay 24 operates, which had been in the ON state until then. After that, the contact 24' of the relay 24 is turned OFF, the illumination circuit is cut off, and the rotation of the feed motor 4 is stopped. It can be applied to many different annular blade proboscises 5, ranging from several types to more than ten types.

The changeover switch 32 is a two-way switch that is switched in conjunction with all the circuits of the second detection section that performs the second stage detection of the cutting resistance of the annular cutter 5.

33 is an emergency warning lamp, and 34 is a rotation speed regulator of the feed motor 4.

Next, the effects of the invention will be explained using the above embodiments.

・The AC voltage of the AC power supply is applied to the full-wave rectifier 7 on the one hand, and the full-wave rectified DC voltage is composed of a capacitor 8, a resistor 9, 10 and a capacitor 11 connected in series. The first direct current is applied to the coil of the relay 12 through the smoothing circuit, and the relay 12 is activated and the contact 12' of the relay is turned ON. On the other hand, the alternating current voltage is applied to the drive motor 3' of the electric drill 3,
The electric drill 3 is rotated, and at the same time, an electric current is applied to the first AC relay 13 to connect the contacts 13-, ]J-JO of the relay.
N.

13-2 becomes OFF.

When the operation switch 14 of the feed motor 4 is turned on, the feed motor 4 rotates and the speed regulator 340 is set. Since the receiver rotates at a predetermined number of revolutions, the electric drill 3 adjusts to its working position and starts the cutting operation.

The above-mentioned cutting operation will continue without any problem if the load on the electric drill is below a predetermined control level, but for example, if the cutting edge of the annular cutter 5 is clogged with chips and is not discharged. 9. As the machined hole gradually becomes deeper and a larger load is applied, the load exceeds a predetermined control level.

In such a case, the present invention detects the load condition and controls the entire operation as follows.

When the cutting resistance of the annular cutter 5 increases and the load on the drive motor 3' of the electric drill 3 increases, the current flowing through the drive motor 3' increases. When a change in voltage is detected by a resistor 15 connected in series with ', the potential difference between both terminals of the resistor 15 increases. This potential difference is boosted by a transformer 16 and converted into a full-wave rectified DC' voltage by a full-wave rectifier 17.

Assuming that the changeover switch 32 is now switched to the state shown in FIG. When the voltage increases and the charging voltage becomes higher than the Zener voltage, the voltage regulator diode 22
A current flows through the relay 23, and a signal current is applied to the relay 23, so that the relay contact 23' is in the ON state. Therefore, relay 24
Since a low current of alternating current flows through and the relay contact 24' is turned off, the power supply circuit of the feed motor 4 is opened and the annular cutter 5
feeding will stop.

Due to the above operation, the load on the electric drill 3 gradually decreases, so when the voltage across the constant voltage diode 22 becomes equal to or lower than the Zener voltage, the voltage applied to the relay 23 becomes 0. Relay contact 23' is restored to its original state,
The contact 24' of the relay 24 again completes the power supply circuit for the feed motor 4, starts the feed motor 4, and resumes the cutting operation by the annular cutter 5.

In the above process, if stopping the feed of the electric drill 3 does not have the effect of reducing the load on the electric drill 3, the signal current ( passes through a resistor 25 and a variable resistor 26, and is taken out by the variable resistor 19. A signal voltage greater than the rc'?s pressure is proportionally distributed and charged to a capacitor 28.

When this signal voltage increases as the load increases and exceeds the Zener voltage of the constant voltage diode 29, the signal voltage passes through the diode 29 and is transferred to the silicon controlled rectifier 31.
As a result, the silicon controlled rectifier element 3
1 is in a conductive state.

The anode of the recon system element 31 is connected to the full wave rectifier 1.
Since the cathode is connected between one side of the capacitor 3o, the input terminal of the silicon control element 31 is short-circuited, and the contact of the relay 12 12' is turned OFF, the power supply circuit is cut off, and the drive motor 3' of the electric drill 3 is stopped. At this time, W at the same time.

The response current of the 1 AC relay 13 is also cut off, and the contact 13-1 of the relay 13 becomes oFF1 contact 13-2idON.
The emergency warning lamp 33 lights up.

In this way, when both the feed motor 4 and the electric drill drive motor 3' stop rotating and the emergency warning lamp 33 lights up, the control side j element 31 is turned off. The power circuit switch 6 is operated to turn off the power circuit of the electric drill 3, the electric drill 3 is returned to the state before work, and the load is removed.

Hereinafter, the invention has been described based on examples, but the invention is equipped with an electric drill 3 that can be fixed vertically to a workpiece, and that moves the electric drill 3 forward and backward with respect to the workpiece. The operating circuit of the electric drill and the feed motor includes a plurality of variable resistors 19 (19) for detecting the load of the electric drill as a change in voltage.
9'), 26 (26') and changeover switch 32.32
a detection section having a control level, and when a signal voltage higher than the control level is provided by the detection section, only the 7L output circuit of the feed motor 4 or the power supply circuit of the electric drill 3 together with the same power supply circuit is cut off; At least, when only the power supply circuit of the feed motor 4 is cut off, a relay circuit is provided that automatically starts refeeding when the signal voltage drops below the control level, so that it is possible to use the electric drill 3 while the electric drill 3 is in use. When the machine is overloaded, it automatically stops operation under overload to prevent damage to the cutting tool, twist drill, and burnout of the drill motor. Since drilling work automatically starts when the load is removed, it also eliminates the cause of lower operating rates that can occur with manual operation.
This has the effect of allowing safe work to be carried out smoothly.

The process can also be performed steplessly using the signal voltage detection sound, the variable resistors 19 (19') and 26 (26') attached to the resistor 18.25, and the changeover switch 32.32. It can be widely applied as a maintenance measure for many types of annular cutting tools 5 and many types of twist drills with different diameters.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is an overall configuration diagram, FIG. 2 is a block diagram of a maintenance circuit, and FIG. 3 is a detailed circuit diagram. In the drawings, symbols]...Frame, 2...%a base, 3...%a drill, 3'...drill motor, 4
・Feed motor, 5...Drilling tool, 6...Start swig, 7゜17...Full wave rectifier, 8, 1.1, 21,
28.30... Capacitor, 9.15. ．． 18,2
0.20'. 25, 27, 27'...Fixed resistance, 10, 12,
23°24...Relay, 19.19', 26,2!3
'...Variable resistor, 22.29... Constant voltage diode, 31... Solicon control element, 32... Changeover switch, 33... Emergency alarm lamp. Patent Applicant: Japan Togiken Co., Ltd. Procedural Amendment (Voluntary) May 7, 1980 Haruki Shimada, Commissioner of the Patent Office 1. Indication of the Case 1986 Patent Application No. 186473 2. Name of Invention: Drilling Machine a Amendment Relationship with the case of the person who filed the patent application Patent applicant (1) I amend section 9 of all appendices to the ILI patent claims. (2) "Same operation circuit...contact 13-IJ" written in page 4, line 18 of specification l to page 5, line 1 is corrected as follows. a contact 24B of a second AC relay 24 connected in series to a contact 23' of the second DC relay 23;
Said relay contact 24B10(3) Specification page 5 line 16, Ki 7 Tei line 6,
r24'J written on page 10, line 5 has been corrected to r24BJ. (4) Next to "33" on page 7, line 15 of the specification, add "connected in series to contact 24A of second AC relay 24" and add 1. (5) "13-1..." written on page 8, lines 8-9 of the specification
It becomes... ” has been corrected in the following passage. "13B °OF Ftonashi, Emergency Guide" Y Le Lamp 33
Open the circuit. ” (6) “24
’ will be OFF, so please correct the following passage 9. “Since 24A is ON and 24B is OF l', the non-lightning warning lamp 33 lights up at the same time” (7)
"13-1" written in page 11, line 11 of the specification is r13
I asked BJ to connect contact 13-2J to 2nd AC relay 24-4.
Correct each point to 24A. (8) "Vertically" written in the first line of page 12 of the specification will be deleted. (9) “Advance movement” written in the third line of the same page is “Advance”
I am corrected. αQ Same page] "Only..." written in lines 0 to 14
..." is corrected as follows. If the power supply circuit of the electric drill is shut off along with the electric circuit, and at least the power supply circuit of the feed motor is shut off, when the signal '1L pressure falls below the control level, "Closing the power supply circuit of the feed motor and restarting the advance of the electric drill." and a feed motor fitting for advancing the electric drill against the workpiece, a plurality of variable resistors and a plurality of variable resistors for detecting the load of the electric drill as large and small voltage changes in the operating circuit of the electric drill and the feed motor. When the detection section has a changeover switch and a signal voltage higher than the control level is generated by the detection section, either the power supply circuit of the above-mentioned feeder motor is cut off, or the power supply circuit of the electric drill is cut off along with the same electric circuit. A drilling machine equipped with a relay circuit that also cuts off the circuit and outputs a signal voltage when at least the power supply circuit of the feed motor is cut off.

Claims (1)

[Claims] An electric drill that can be fixed vertically to a workpiece, and a feeder motor for moving the electric drill forward and backward relative to the workpiece, and an operating circuit for the electric drill and the feeder motor include a A detection section has multiple variable resistors and changeover switches that detect the load of the electric drill as large and small changes in voltage, and when a signal voltage higher than the control level is provided by the detection section, only the power supply circuit of the feeder motor is activated. Or, if the electric drill's illumination circuit is also cut off along with the same electric circuit, and at least when only the feed motor's illumination circuit is cut off, it is possible to automatically start re-feeding when the signal voltage falls below the control level. - circuit f: provided drilling machine;