JP2866548B2 - Discharge type cladding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge type cladding apparatus for depositing an electrode bar on the surface of a metal work by discharging between the electrode bar and the metal work.

[0002]

2. Description of the Related Art The mold used for resin injection molding and aluminum die casting is made of iron. However, the joint surface between the molds and the portion where the molten metal collides at high speed are worn or chipped, so that a gap or deformation occurs in the joint. These gaps and deformations cause burrs and distortion of the product, increase the deburring work and shaping work in the subsequent process, and cause the generation of defective products. or,
When a foreign object such as a tool enters a metal roller such as a film roller, an emboss roller, or a printing press roller, a dent is generated in the metal roller, and the product is defective. Repair of a metal work, such as the above-mentioned mold and metal roller, is usually performed by removing the metal work from an apparatus such as an injection molding apparatus, overlaying the work by argon welding or the like, and then polishing.

[0003]

For this reason, since the metal work is removed and transported, repair costs and time are required.
Further, the temperature of the metal work becomes high due to the welding operation, and the metal work undergoes thermal distortion. Therefore, the inventors connected one end of the resistor to the plus terminal of the DC power supply, connected the minus lead of the capacitor to the minus terminal, and connected the plus lead of the capacitor to the other end of the resistor. Connect the electrode rod that rotates (to prevent fusion of the electrode rod) to the positive lead of the capacitor with a cable, connect the metal work and the negative lead of the capacitor with a ground cable, and connect the electrode rod to the metal work. A discharge-type cladding apparatus capable of depositing an electrode bar on the surface to be repaired to a thickness of several tens μm to several mm by a spark discharge generated between the two was brought close to the surface to be repaired. In this prototype, the metal workpiece is not heated to a remarkably high temperature, and the overlaying operation can be performed while the metal workpiece is mounted on an apparatus such as an injection molding apparatus.

However, the following new problems have been found in this prototype. If the material of the metal work and the shape and size of the surface to be repaired are different, the overlay work cannot be performed efficiently. The charge stored in the capacitor is lost in a short time, the sustaining of the discharge is poor, and the working efficiency is poor. When the electrode rod is separated from the metal work, a high voltage is applied between the electrode rod and the metal work, and there is a possibility that the worker may be electrocuted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge-type cladding apparatus capable of efficiently performing a cladding operation even when the type of a metal work is different. An object of the present invention is to provide a cladding device and a discharge-type cladding device excellent in safety.

[0006]

The present invention has the following features to attain the object mentioned above. A power supply for generating a DC voltage of tens to hundreds of volts, a resistor having one end connected to one terminal of the power supply, one lead connected to the other end of the resistor, and the other lead connected to the other terminal of the power supply A capacitor, an electrode rod electrically connected by a cable to a lead side of the capacitor that is positively charged, and provided with vibration or rotation around an axis by a driving mechanism, and a lead side of the capacitor that is negatively charged and metal. A grounding cable for electrically connecting the work piece to the work piece, bringing the electrode rod close to the repaired face of the metal work piece, and depositing the electrode rod material on the repaired face by spark discharge generated between the two. In a discharge-type cladding apparatus, the voltage of the capacitor is equal to or higher than a predetermined value.
In the case of the lead side of the capacitor that is charged positively
Safety means for interrupting the electrical connection between
You.

[0007]

The capacitor is charged via a resistor.
Since the lead side of the negatively charged capacitor and the metal work are electrically connected by a ground cable, and the lead side of the positively charged capacitor and the electrode rod are electrically connected by a cable, the electrode rod has a positive potential. Becomes When the electrode rod is brought close to the repaired surface of the metal work, a spark discharge is generated between the electrode rod and the metal work, and the electrode discharge is deposited on the repaired surface by the spark discharge. The drive mechanism applies vibration or rotation around an axis to the electrode bar to prevent fusion between the electrode bar and the metal work. Electrode rod and metal work
Spark discharge stops when it is far away from the
Charging voltage rises to almost the power supply voltage,
When the voltage of the battery exceeds a predetermined value,
Safety measures for electrical connection between the lead side of the densa and the cable
Since the cutoff is performed, the potential of the electrode rod becomes zero.

[0008]

When the safety means is not provided, the electrode rod is made of metal.
If you state you release from the manufacturing work, electricity Gokubo and metal word
Because a DC voltage of several tens to several hundreds of volts is applied between
There is a risk that an operator may accidentally touch the electrode rod and get an electric shock. Only
Safety measures, and ensure that the capacitor voltage is
The positive side of the capacitor and the cable
The electrical connection to the cable is cut off.
The worker accidentally touches the electrode rod when the
No electric shock and excellent safety.

[0009]

Next, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG.
Is mounted on a conductive metal main body a in which a power supply circuit 1 for converting alternating current to direct current, a resistor 2, a capacitor 3, a switching circuit 4, a safety circuit 5 for preventing electric shock, and the like, and an applicator b. It has a rotating electrode rod 6 and an earth cable 8 connected to an iron work 7.

A power supply circuit 1 has a transformer (capacity: 1 k) having a primary winding connected to a commercial power supply of AC 100 V and having a turn ratio of 1: 1.
W) 11 and the AC 1 generated in the secondary winding of the transformer 11
A diode bridge 12 for full-wave rectification of 00V and a smoothing capacitor (470 for reducing ripple of ripple current)
And a bleeder resistor (1.5 kΩ-20 W) 1 for suppressing a rise in rectified voltage at no load and discharging when the power switch 10 is turned off.
4 and the positive terminal 1 of the power supply circuit 1 when there is no load.
5. A DC voltage of about 141 V is generated between the minus terminal 16 (both ends of the smoothing capacitor 13).

A resistor 2 (20 Ω-300 W) is for charging the capacitor 3, and one end 21 is connected to the power supply circuit 1.
, And the other end 22 is connected to the plus lead 31 of the capacitor 3. Note that the resistor 2 is air-cooled by the fan 23.

The capacitor 3 (10 μF) connects the negative lead 32 to the negative terminal 16 of the power supply circuit 1 (= the body of the main body a). Also, the output adjustment switch 33,
When 34 and 35 are turned on, two capacitors 30 each having the same capacity as the capacitor 3 are provided at both ends of the capacitor 3.
Four, seven, connected, each with a combined capacitance of 30 μF, 5
0 μF and 80 μF. When all the output adjustment switches 33, 34, 35 are turned on, the combined capacitance becomes 140 μF.

The switching circuit 4 includes an SCR 41 and an SCR 41.
A pulse-like gate current is supplied to the CR 41 so that the anode 41
1 and a trigger pulse generating circuit 42 for periodically turning on between the cathodes 412. The pulse frequency can be varied between 20 and 1000 Hz by the variable resistor 43.

The safety circuit 5 includes a cathode 41 of the SCR 41.
2- A resistor 51 is connected between the minus terminal 16 of the power supply circuit 1.
(1.5 kΩ-20 W), a diode block 52 in which three constant voltage diodes having the same characteristics are connected in series, a relay 53 and a capacitor 54, and a reset switch 55 which is normally closed and opened when pressed. Between the first circuit that activates the relay 53 when the potential of the cathode 412 becomes 90 V or more, and the AC relay 5 between the AC 100 V and the first circuit.
6 that is connected to the break contact 531 of the relay 53
Make contacts 561, 5 of the AC relay 56 connected between the circuit and the cable 61 and the cathode 412 of the SCR 41.
62. When the relay 53 is activated, the make contact 532 of the relay 53 is closed and the LED 5
7 lights up to notify the worker.

The electrode rod 6 is made of pure Ni or 30 wt% or more Ni, 5 to 20 wt% Mo, 10 to 30 wt% C
r, containing 1 to 20 wt% Fe, outer diameter 1 to 10 mm
And is rotated at a predetermined rotation speed (10 to 1000 rpm) by a motor 905 in the applicator b.

The applicator b uses a gun-type electric hand drill as shown in FIG.
And a housing 903 comprising a grip portion 902 protruding below a rear end portion. A rotary switch 904 for supplying AC 100 V to the motor 905 is provided on the front surface of the grip 902. The motor 905 is provided inside the main body 901, and the output shaft 906 is electrically connected to the cable 61. Is rotatably mounted. A chuck 9 for gripping the electrode rod 6 is provided at the tip of the output shaft 906.
07 is attached so as to protrude from the main body.

The housing 903 is a tip portion of the gun-type electric hand drill (a portion covering the output shaft 906).
Has been removed, and the output shaft 9 is used instead of the removed tip portion.
A resin sleeve 908 enclosing the distal end portion of the outer casing 06 is externally fitted. A cover tube 910 that covers the chuck 907 and guides the argon gas released from the gas hose 909 is fitted to the sleeve 908 (the distal end portion of the housing 903).

An axial sleeve 911 is formed in the insulating sleeve 908, and a brush 912 connected to the cable 61 is fitted into the slit 911 in sliding contact with the output shaft 906. A circumferential groove 913 intersecting with the slit 911 is formed on the outer periphery of the sleeve 908, and a ring 913a of a coil spring for pressing the brush 912 against the output shaft 906 is fitted in the circumferential groove 913.
The sleeve 908 has a through hole 9 parallel to the slit 911.
14 is opened to form an argon gas passage.

The cover cylinder 910 fits tightly on the sleeve 908 and has a large-diameter body 915 loosely fitted on the outer periphery of the chuck 907, and a tapered portion 91 provided at the end thereof.
6. Small-diameter portion 917 protruding from the tip of tapered portion 916
Consists of An insertion hole for a fastener for fastening the chuck 907 is formed in the small-diameter portion 917, and a funnel-shaped cap 918 made of resin is detachably fitted to the outside. The funnel-shaped cap 918 is attached so that the convenience of attaching and detaching the electrode rod 6 and the argon gas can be concentrated and flow along the electrode rod 6.

[0020] Through hole 914 connected to gas hose 909
An outlet 919 is opened at the end face of the sleeve 908 to form a gas flow path reaching the inside of the cover cylinder 910, and argon gas is blown out from the tip of the funnel-shaped cap 918.

The iron work 7 is a mold, a roller, or the like manufactured by SKD61, S50C, or the like.

The ground cable 8 is a copper wire for electrically connecting the minus terminal 16 (= body of the main body a) of the power supply circuit 1 and the iron work 7, and a work gripper 81 sandwiched between the iron work 7 is attached to the tip. ing.

Next, the work of repairing the build-up of the iron work 7 by the discharge type build-up apparatus A will be described. After setting the variable resistor 43 so as to obtain a pulse frequency suitable for the iron work 7 (determined from the contained metal material), the power switch 1
0 is turned on, the output adjustment switches 33, 34, and 35 are turned on so as to have a capacitor capacity suitable for the iron work 7, and the gas release knob 931 of the argon gas cylinder 930 is turned.
The tip of the electrode rod 6 is brought close to the repaired surface 71 of the iron work 7 and the rotation switch 904 is pressed. At this time, LED5
If 7 is lit, press and release the reset switch 55.

When 100 V AC is applied to the motor 905 and the electrode rod 6 rotates at a predetermined rotation speed, and the switching circuit 4 switches the charging voltage of the capacitor 3 and the like, the pulse voltage of 20 to 1000 Hz is applied to the electrode rod 6. Is applied. Argon gas is supplied from a gas cylinder 930 to a gas discharge knob 931... A gas hose 909 → a through hole 91.
4 → Exit 919 → Cover cylinder 910 → Funnel-shaped cap 91
8 flows out along the tip of the funnel-shaped cap 918 and flows along the electrode rod 6.

A spark discharge is generated between the electrode rod 6 and the iron work 7, and the spark discharge melts the electrode rod material of the electrode rod 6 having a positive potential, and the repaired surface 71 of the iron work 7 having a zero potential has The electrode rod material is deposited in a shield atmosphere of argon gas. The vapor deposition is performed by charging the molten electrode bar to a positive potential, sucking the surface of the iron work 7 having a zero potential, and colliding with the surface 71 to be repaired. A layer is formed. At this time, since the electrode rod 6 is rotating, the tip of the electrode rod 6 is
Can be prevented from being fused to the surface of the electrode, the build-up work can be performed smoothly, and the formed electrode material layer is uniform and the surface is smooth. The rotation speed of the electrode rod 6 is 10 rpm
The workability of the overlaying work is high in the range of m to 1000 rpm.

FIG. 5 shows a process of repairing a resin injection molding die by the electric discharge type cladding apparatus A. (A) The proper position of the mold 72 is gripped by the work gripper 81 of the ground cable 8, and after setting the variable resistor 43, the power switch 10 is turned on and the desired output adjustment switches 33, 3
4 and 35 are turned on, the gas release knob 931 of the argon gas cylinder 930 is turned, the tip of the electrode rod 6 is brought close to the repair surface 721 of the mold 72, and the rotary switch 904 is pressed. (B) While the electrode rod 6 rotates, an electrode material is deposited on the surface to be repaired 721 in an argon gas atmosphere, and the surface to be repaired 721 of the mold 72 is overlaid. (C) When the repair surface 721 is completely overlaid, the overlaid surface 73 is finished by grinding or polishing.

Next, the advantages of this embodiment will be described. In the case where there are many metals other than iron among the metals constituting the metal work, or when the repaired surface 71 is deep and large,
It is necessary to increase the duration of the discharge. In the discharge-type cladding apparatus A, a desired discharge duration can be obtained by considering the combination of turning on the output adjustment switches 33, 34, and 35, and the cladding operation can be performed efficiently.

The trigger pulse generating circuit 42 of the switching circuit 4 periodically turns on between the anode 411 and the cathode 412 of the SCR 41,
(Including the capacitor 30 when the output adjustment switch is turned on) is applied to the electrode bar 6 at a time to prevent the charge from being lost early. Also, the variable resistor 43
The pulse frequency can be varied between 20 and 1000 Hz. For this reason, the charged electric charge of the capacitor 3 and the like is intermittently applied to the electrode rod 6, so that the continuity of the spark discharge is improved and the overlaying operation can be performed efficiently. If the pulse frequency is less than 20 Hz, S per unit time
Since the CR ON time is shortened, the intensity of the spark discharge becomes inferior. When the frequency exceeds 1000 Hz, the effect of extending the remaining charge is reduced.

With the power switch 10 turned on,
The electrode rod 6 separates from the iron work 7 and the mold 72, and the electrode rod 6
-If discharge is not caused between the iron work 7 and the mold 72, the cathode potential of the SCR 41 exceeds 90 V, the relay 53 is activated, the break contact 531 is opened, and the AC relay 56 is deactivated and the makeup is stopped. Contacts 561, 56
2 are both opened, and the voltage applied to the electrode rod 6 is set to zero. For this reason, even if an operator accidentally touches the electrode rod 6 in a state where the electrode rod 6 is separated from the iron work 7 and the mold 72 and the discharge-type cladding apparatus A is left in the operating state, an electric shock is caused. There is no thing and it is excellent in safety.

The work 11 made of iron is formed by the transformer 11
Work can be performed without electrical insulation between the metal mold 72 and the ground. Even if the iron work 7 or the metal mold 72 is touched while the ground cable 8 is connected, there is no electric shock. Excellent and safe. In addition, the transformer 11 reduces the amount of radio noise entering the commercial power supply line.

The present invention includes the following embodiments in addition to the above embodiments. a. The drive mechanism may employ a configuration in which rotation around the axis and vibration are simultaneously applied to the electrode rod 6, or a configuration in which only vibration is applied to the electrode rod 6. b. The type of the shielding gas is preferably an inert gas, but need not be used. c. The primary winding of the transformer 11 may have a 200V specification and a three-phase specification. Further, the magnitude of the secondary voltage of the transformer 11 may be such that the rectified voltage is about 50 V to 300 V, and taps such as 80 V, 90 V, 110 V, and 120 V may be provided on the secondary winding so as to be selectable.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a working state of a discharge-type cladding apparatus according to the present invention.

FIG. 2 is an electric circuit diagram (entire) of a main body of the discharge-type cladding apparatus.

FIG. 3 is an electric circuit diagram (part) of a main body of the discharge-type cladding apparatus.

FIG. 4 is a structural explanatory view of an applicator used in a discharge-type cladding apparatus.

FIG. 5 is a repair process diagram of an injection mold using an electric discharge type overlaying apparatus.

[Explanation of symbols]

 A Discharge type cladding device 1 Power supply circuit (power supply) 2 Resistance 3 Capacitor 5 Safety circuit (safety means) 6 Electrode rod 7 Iron work (metal work) 8 Earth cable 15 Positive terminal (one terminal) 16 Negative terminal (other terminal) ) 21 One end 22 Other end 31 Positive lead (one lead) 32 Minus lead (other lead) 61 Cable 71 Repair surface 72 Mold (metal work) 721 Repair surface 905 Motor (drive mechanism)

Claims (1)

(57) [Claims] 1. A power supply for generating a DC voltage of several tens to several hundreds of volts, a resistor having one end connected to one terminal of the power supply, one lead connected to the other end of the resistor, and the other lead connected to the power supply. A capacitor connected to the other terminal of the capacitor, an electrode rod electrically connected by a cable to a lead side of the capacitor that is positively charged, and provided with vibration and rotation around an axis by a driving mechanism, and the capacitor that is negatively charged An earth cable for electrically connecting the lead side of the metal work to the metal work, bringing the electrode rod close to the repaired surface of the metal work,
In a discharge-type cladding apparatus for depositing an electrode rod on the surface to be repaired by a spark discharge generated between the two, when the voltage of the capacitor is equal to or higher than a predetermined value, the battery is charged positively.
Between the lead side of the capacitor to be charged and the cable
A discharge-type cladding apparatus characterized by providing a safety means for interrupting electrical connection .