JPS5856829B2 - HOROYO YOKUSO NO BINHORU KENSAHOHO OYOBI SOUCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a pinhole inspection method for detecting the presence or absence of pinholes in an enamel bathtub.

Pinholes are not allowed in enamel bathtubs.

This is because if there are pinholes, rust will occur from the iron fabric,
This is because it will cause a hole-opening accident.

These pinholes are so small that they are difficult to detect with the naked eye, and various inspection methods have been developed to date.

Some examples will be explained below.

(T) First, to explain the electrolysis method, a felt electrode is soaked in a solution of saline solution containing phenolphthalene, and the electrode is connected to the + side of a DC power source (60 to 80 V).
The enamel bathtub to be inspected for pinholes is connected to one side of the DC power source, and then the felt electrode is scanned by stroking the entire outer circumferential surface of the bathtub so as not to leak any contact.

If there is a pinhole, electricity is applied and the chlorine in the saline solution is electrolyzed on one side of the electrode and the caustic soda on the + side of the electrode.

Furthermore, the phenolphthalene added to the saline reacts red due to the caustic soda generated on the + side.

In other words, the existence and position of a pinhole is detected by the red liquid on the surface of the enamel bathtub.

(II) Also, in the neon electroscope method, the felt electrode connected and scanned as described above is connected to the electrode, a 240V DC power source is used as the power source, and a stacked battery or rectifier circuit is used as the detection device.
A neon detector tube connected in series with a resistor of Ω is used, and if there is a pinhole, the neon detector tube will ignite.

(1) In the pulse discharge method, a metal brush is used as an electrode, and a low-frequency pulse discharge voltage of several thousand volts or more is applied to the electrode for inspection.

If there is a pinhole, a spark discharge will occur.

(IV) In the high-frequency discharge method, a power switch is turned on to generate a spark discharge between the discharge gaps and discharge the electric charge stored in the capacitor.

At this time, a high frequency current flows through the primary coil of the discharge tube, and the
A very high voltage is generated on the next side.

This secondary side is connected to a needle-shaped or blade-shaped copper alloy electrode, and when the electrode is brought close to an enamel bathtub, a purple corona discharge is generated from the electrode to the bathtub surface, and if there is a pinhole, a white discharge occurs. spark discharge occurs.

In other words, it distinguishes between corona discharge and spark discharge and detects the presence and location of pinholes.

The above inspection methods (1) to (fV) require the electrode to be moved over the entire outer circumferential surface of the enamel bath including the curled upper edge of the bath so as to avoid scanning omissions, which is time-consuming (inspection efficiency is low). ) There was a defect.

In addition, the enamel bathtub, which is the object to be inspected, has a large surface area,
There are bent parts between the bathtub body and the curled upper edge, between the side plates, and between the side plates and the bottom plate, which make it difficult to scan the electrodes. The unavoidable flaw was that pinholes were overlooked.

The present invention addresses the above-mentioned problems, and includes a hollow electrode body having a similar shape and an outer diameter slightly smaller than the inner diameter of the enamel bathtub, and a hollow electrode body that is attached to the enamel bathtub so as to cover the outer peripheral surface of the electrode body. a porous elastic material layer, a felt layer attached to cover the outer peripheral surface of the elastic material layer, a water tank installed in the electrode body, and an opening from the water tank penetrating the electrode body to the elastic material layer. A felt made of a water absorption pipe and a water absorption filler filled in the water absorption pipe is inserted into the bathtub, and the outer circumference of the electrode is placed on the entire inner circumference of the bathtub and on the upper outer circumference of the electrode. Pinholes in an enamel bathtub characterized in that the pinholes in the bathtub are inspected by placing the flanges of the bathtub in close contact with the curled upper edge of the bathtub, applying a DC voltage, and inserting the electrode once. Regarding the inspection method, its purpose is:
The presence or absence of pinholes can be detected by inserting the electrode once, improving inspection efficiency.

No false positives occur. Another object of the present invention is to provide an improved method for inspecting pinholes in an enamel bathtub, which can repeatedly, smoothly and reliably inspect the presence or absence of pinholes.

As described above, the pinhole inspection method for an enamel bathtub according to the present invention includes a hollow electrode body that has a similar shape to the enamel bathtub and whose outer diameter is slightly smaller than the inner diameter of the bathtub, and a hollow electrode body that covers the outer peripheral surface of the electrode body. a porous elastic material layer attached to the electrode body, a felt layer attached to cover the outer peripheral surface of the elastic material layer, a water tank installed in the electrode body, and the elastic material layer passing through the electrode body from the water tank. A felt electrode consisting of a water suction pipe opened at the bottom and a water absorption filler filled in the water suction pipe is inserted into the bathtub, and the outer peripheral surface of the electrode is placed on the entire inner peripheral surface of the bathtub. The flange provided on the outer periphery of the upper part is brought into close contact with the curled part of the upper edge of the bathtub, a DC voltage is applied, and pinholes in the bathtub are inspected by inserting the electrode once, and the entire surface of the bathtub is inspected for pinholes. Compared to the conventional method, which requires repeated scanning with an electrode held in the hand of an inspector, inspection efficiency can be significantly improved.

Furthermore, since the felt electrode is used, there is an advantage that no detection error occurs.

The felt electrode is constructed as described above, and when the electrode is lowered and inserted into the enamel bathtub on the bathtub holding device,
The elastic material layer is elastically deformed in the compression direction, and the felt layer is brought into close contact with the entire inner circumferential surface and the upper edge curl portion of the enamel bathtub.

When the electrode is lifted up and removed from the enamel bath, the elastic material layer returns to its original state.

Therefore, the water in the water tank is sucked into the elastic material layer and the felt layer through the filling material in the water suction pipe, and the water that has decreased due to evaporation or adhesion to the bathtub is replenished to the felt layer in preparation for the next test.

Therefore, the presence or absence of the pinhole can be checked repeatedly and smoothly and reliably.

Further, in the pinhole inspection method of the enamel bathtub, the present invention provides that when the felt electrode is inserted into the enamel bathtub and a DC voltage is applied, the circuit of the detection microampere make relay is connected by the b contact of the transient phenomenon absorption timer. The present invention relates to a pinhole inspection method for an enamel bathtub, which is characterized by short-circuiting and preventing the detection microampermeter relay from being activated by the transient current that flows when the voltage is applied, which has the effect of preventing inspection failure.

That is, the felt electrode for inspecting pinholes in the enamel bathtub is almost the same as the bathtub, and is very large.

When this felt electrode is inserted into a bathtub and a DC voltage is applied, a transient current flows, instantly forming a capacitor with the enamel layer as a dielectric, regardless of whether there is a pinhole or not.
The detection micro ampere meter relay malfunctions and becomes untestable, but the present invention is configured as described above, and the transient current is absorbed by the transient phenomenon absorption timer.
During this time, the detection micro ampere meter relay was not activated, which has the effect of preventing failure to perform testing.

Next, the pinhole inspection method for an enamel bathtub according to the present invention will be explained using an embodiment shown in FIGS. 1 to 5. In FIG. 1, 1 is a transformer, 2 is a rectifier, 3 is a DC circuit, and 4 is the same. An electrode connected to the + side of the DC circuit 3, 5 an enamel bathtub to be inspected for pinholes, 6 a pair of bathtub support members that suspend and support the bathtub 5, and the bathtub 5 is supported by the support member 6. Then, the bathtub 5 is connected to one side of the DC circuit 3.

Reference numeral 7 denotes an electrode lifting device (lifting hoist), and when the electrodes 4 are lowered by the lifting device 7 and inserted into the bathtub 5 and come into close contact with each other, and if there is a pinhole in the bathtub 5, A minute current flows through the DC circuit 3.

That is, when the voltage of the DC circuit 3 is 240 mm, a 5 MΩ resistor of 8240 mm is included in the circuit 3, and a minute current of □l=50 μA flows.

This minute current is detected by the detection non-contact micro ampere meter relay 9, and sent to the power relay 11 of the detection circuit 10, which activates.
The NG indicator light 12 lights up and the NG buzzer 13 sounds.

Next, the electrode 4 will be explained in detail with reference to FIG.

14 has a similar shape to the bathtub 5 and has the same outer shape as the bathtub 5.
15 is a polyethylene foam elastic material layer affixed to the outer surface of the electrode body 14, and 16 is affixed to the outer surface of the elastic material layer 15. a felt layer, 17 a water tank provided in the electrode body 14, and 18 a water tank 17;
A water absorption pipe that penetrates the electrode main body 14 from inside and opens into the elastic material layer 15, 19 is a water absorption felt filled in the water absorption pipe 18, and 20 is a water absorption pipe 1 of the elastic material layer 15.
A soft urethane water-absorbing foam filled with the opposing portions of 8 instead of being cut out so as to go around the electrode body 14;
Reference numeral 21 indicates water in the water tank 11, and the outer diameter of the felt layer 16 is slightly larger than the inner diameter of the bathtub 5.

Next, the electrode lifting device 7 and the bathtub holding device 22 are moved to the third and fourth positions.
This will be explained in detail with reference to the drawings.

First, the bathtub holding device 22 will be explained. 23 is four columns, 24 is an upper plate that connects the upper ends of each column 23, and the bathtub support members 6, 6 are the 4 columns of the columns 23. It is attached via an arm 25 to approximately the center of the two columns 23 on the left side and the two columns 23 on the right side when viewed from the direction.

Further, 26 is a lower plate connecting the lower ends of each of the pillars 23, 27 is a bearing attached to both ends of the front and back plates 26 of each plate 26 when viewed from the direction of FIG.
Of the bearings 27, 28 and 28 are the left bearings 27 at the front and back when viewed from the direction of FIG. 4, and the right bearings 2 at the front and back.
A wheel axle 7 is supported by a wheel axle, and a wheel 29 is a wheel to which each wheel axle 28 is attached, and the frames 23 to 26 can be moved in the direction of arrow A in FIG. 4 by the wheel 29 and a rail (not shown). It looks like this.

30 is a lift mechanism support member attached to the front and rear plates 26 when viewed from the direction of FIG. 4 among the plates 26, and 31 is a lift mechanism whose lower end moves in the direction of the arrow in FIG. 3. It is attached to the support member 30 so as to be able to do so.

Further, 32 is a roller conveyor supported by the lift mechanism 31, 33 is a rubber-lined roller of the conveyor 32, 34 is an electrode plate attached to the center of the bathtub support member 6, and 35 is a top of the electrode plate 34. 36 is a rubber layer attached to both ends of the support member 6, 37 is a bathtub carrying conveyor, 38 is a bathtub carrying conveyor, and the enamel bathtub 5 is carried from the carrying conveyor 38 onto the roller conveyor 33. Then, the handle and eccentric cam (not shown) are manually turned, and the lift mechanism 31 that moves up and down in contact with the cam, the roller conveyor 32 above it, and the bathtub 5 descend, causing the upper edge of the bathtub 5 to curl. When the inspection is completed, the handle and the eccentric cam are manually rotated so that the portion 5a is in contact with the felt layer 35 and the bathtub 5 is connected to one side of the DC circuit 3.
2 and the bathtub 5 rise, and the bathtub 5 is transferred to the roller conveyor 3.
2 to a carry-out conveyor 38.

Further, there are a plurality of carry-in conveyors 31 and a plurality of carry-out conveyors 38, and when the bathtub 5 is carried out to the carry-out conveyor 38, the frames 23 to 26 move to a position facing another carry-in conveyor 37 and a carry-out conveyor 38. and prepare for the next inspection.

Next, the electrode lifting device 7 will be described. 39 is a guide bush support plate fixed to the upper plate 24, 40 is a guide bush fixed to the support plate 39, and 41 is movable by the kite bush 40. A supported guide shaft, 42 an electrode support plate fixed to the lower end of the guide shaft 41, 43 an upper frame fixed on the upper plate 24, and 44 a motor mounted on the upper plate 24 (
45 is the sprocket of the motor 44 (see FIG. 3), 46 is the reducer, and 47.48 is the reducer 46.
sprocket, 4th gear is above sprocket 1-45.47
The chain 49.50 suspended between the upper frame 4
A coaxial sprocket 51 mounted on the upper surface of 3 is a chain suspended between the sprockets 48 and 49, 5
2 is a sprocket attached to the electrode support plate 42;
53 is a sprocket attached to the upper surface of the upper frame 43, and 54 is a chain attached to the counterweight 55 from the upper part of the upper frame 43 via the sprocket 52 and 50. When the motor 44 is driven in the forward direction, , Sprocket 45 Chain 48' Sprocket 47 Reducer 4
Sprocket 5 via 6 sprocket 48 chain 51
0 is driven in the positive direction, the sprocket 52 side of the chain 54 is pulled up, the electrode support plate 42 and the electrode 4 are raised (so that the counterweight 55 is lowered), and the motor 44 is driven in the negative direction. Then, the sprocket 50 is driven in the negative direction, the sprocket 52 of the chain 54 is paid out, and the electrode support plate 42 and the electrode 4
is lowered and inserted into the bathtub 4 on the roller conveyor 32.

In addition, 9a in Fig. 5 is the contact point of the detection micro ampere meter relay 9, and 56 is the contact point for manual pinhole inspection of the enamel bathtub.
57a is a push button switch for electrode lowering, 5γb is a push button switch for electrode raising, 58 is a manual test push button switch, 59 is an automatic start push button switch, 60 is a micro ampere meter relay check push button switch, 61 is an OK display 62 is the timer for absorbing transient current, 63 is the timer for adjusting the test time, 64 is the power indicator light, CKS is the blade type switch, CM is the electromagnetic switch for lowering the electrode, CM2 is the electromagnetic switch for raising the electrode, CR , is the auxiliary relay for automatic start, CR2 is the auxiliary relay for confirming the lowering end of the electrode and starting the test, CR3 is the auxiliary relay for completing the test, CR4 is the auxiliary relay for completing one cycle, and CRX is the auxiliary relay for the detection micro ampere meter relay 9.
g is the a contact of each of the above-mentioned switches and each of the above-mentioned auxiliary relays, →r
or the b contacts of each of the above-mentioned switches and each of the above-mentioned auxiliary relays.

Next, the operation of the pinhole inspection device will be explained.

To switch between manual and automatic, use the changeover switch 56 in Figure 5.
This is done by switching.

When the switch 56 is switched to manual mode, first press the electrode lowering push button switch 57a to drive the motor 44 in the negative direction to lower the electrode 4 and insert it into the bathtub 5 on the bathtub support member 6. The electrode 4 is brought into close contact with the bathtub 5.

Next, the manual test pushbutton switch 58 is pressed to turn on the power and begin pinhole inspection.

If there is no pinhole, the OK indicator light 61 lights up, and if there is a pinhole, the NG indicator light 12 lights up and at the same time the NG buzzer 13 is activated.

When the test is finished, press the electrode raising push button switch 57b to drive the motor 44 in the forward direction and raise the electrode 4.
Remove from bathtub 5.

In addition, when the changeover switch 56 is switched to automatic,
Press the automatic start pushbutton switch 59.

Then, the automatic start auxiliary relay CR1 operates and holds itself, the electrode lowering electromagnetic switch CM1 is turned on, the motor 44 is driven in the negative direction, and the electrode 4 is lowered.

When the electrode 4 descends to the lower limit position and comes into close contact with the bathtub 5, the lowering end detection limit switch LS is activated.

At the same time that the b contact of is broken and the motor 44 and electrode 4 are stopped, the lowering end detection limit switch LS.

The A contact is turned on, and the auxiliary relay CR2 for confirming the lowering end of the electrode and starting the test is turned on and self-holding.

At this time, the transient phenomenon absorption timer 62 starts operating.

Also, when the electrode confirmation and test start auxiliary relay CR2 is turned on, the primary input is applied to the DC power supply (see 1 and 2°8 in Figure 1), a DC voltage is generated on the secondary side, and the DC voltage is applied. be done.

At this time, regardless of whether there is a pinhole in the enamel bathtub 5 or not, a capacitor with the enamel layer as a dielectric is formed at that moment and a transient current flows, but the circuit of the detection micro ampere meter relay 9 The b contact of the phenomenon absorption timer 62 is short-circuited, and the detection microampere meter relay 9 does not malfunction.

Furthermore, when the transient phenomenon absorption timer 62 times up, the detection microampere meter relay 9 is passed through the bathtub 5.
A current flows through the pinhole, and the presence or absence of a pinhole is detected.

If there is no pinhole, no current flows through the microamperemeter relay 9, so the auxiliary relay CRX of the detection microamperemeter relay 9 does not work, and the OK indicator light 61 is lit by its b contact.

In addition, if there is a pinhole, current flows to the detection micro ampere meter relay 9, the auxiliary relay CRX of the detection micro ampere meter relay 9 is activated, and its a contact turns on the NG indicator light 12, and at the same time the NG buzzer 13 is activated.

Further, when the test time adjustment timer 63 times up, the test end auxiliary relay CR3 is turned on, and its b contact releases the self-holding of the automatic start auxiliary relay CR, and also releases the primary input of the DC power supply.

Further, the electromagnetic switch CM2 for raising the electrode is inserted, and the electrode 4 is raised.

When the electrode 4 rises to the upper limit position, the b contact of the rising edge detection limit switch LS2 is disconnected, and the motor 44 and electrode 4
At the same time as stops, the rising end detection limit switch LS2
The a contact is turned on, the auxiliary relay CR4 for completing one cycle is turned on, and the b contact releases the self-holding of the auxiliary relay CR2 for confirming the lowering end of the electrode and starting the test, and one cycle is completed.

Thereafter, in the same manner, the bathtub 5 is replaced and the presence or absence of pinholes is inspected.

Although the present invention has been described above using an embodiment shown in FIGS. 1 to 5, the present invention is of course not limited to such an embodiment, and various modifications may be made without departing from the spirit of the present invention. The design can be modified.

For example, the felt layer 16 of the electrode 4 may be supplied with a saline solution containing phenolphthalene.

In addition to the detection circuit, a pinhole position confirmation circuit is provided which has a low circuit voltage of 50V DC or less and has a low circuit resistance so that if a pinhole exists, a current of several milliamperes can be passed through the detection circuit. If the detection circuit is automatically switched to the same position confirmation circuit when a pinhole is detected and the NG clamp lights up, the pinhole area will turn red, similar to the existing electrolytic method, and the pinhole will be detected. You can check the location of

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the pinhole inspection device for an enamel bathtub according to the present invention, FIG. 2 is a vertical side view of an electrode, and FIG. 3 is a side view of an electrode lifting device and a bathtub holding device. 4 are other side views of the respective devices, and FIG. 5 is an electric circuit diagram. 1.2...Power supply circuit, 3...DC circuit, 4...Electrode, 5...Enamel bathtub, 7.
... Electrode lifting device, 9 ... Detection micro ampere meter relay 10 ... Detection circuit,
12...NG indicator light, 13...NG buzzer 14... Electrode body, 15... Porous elastic material layer, 16... Felt layer, 17...
...Aquarium, 18...Water suction pipe, 19...
... Water absorption filler, 22 ... Bathtub holding device, 6
1: OK indicator light, 62: Transient phenomenon absorption timer

Claims (1)

[Claims] 1. A hollow electrode body that has a similar shape to the enamel bathtub and whose outer diameter is slightly smaller than the inner diameter of the bathtub, and a porous elastic body installed to cover the outer peripheral surface of the electrode body. A felt layer attached to cover the outer peripheral surface of the elastic material layer, a water tank installed in the electrode body, and a water suction pipe that penetrates the electrode body from the water tank and opens into the elastic material layer. A felt electrode made of the water absorption filler filled in the water absorption pipe is inserted into the bathtub, and the outer circumferential surface of the electrode is placed on the entire inner circumferential surface of the bathtub, and the flange provided on the upper outer circumference of the electrode is inserted into the bathtub. A pinhole inspection method for an enamel bathtub, characterized in that pinholes in the bathtub are inspected by inserting the electrode once by applying a direct current voltage after the two electrodes are brought into close contact with the curled portion of the upper edge of the bathtub. Method. 2. In the pinhole inspection method for an enamel bathtub, when the felt electrode is inserted into the enamel bathtub and a DC voltage is applied, the circuit of the detection microampere meter relay is short-circuited by the b contact of the transient phenomenon absorption timer. A pinhole inspection method for an enamel bathtub, characterized in that the detection micro ampere meter relay is not activated by the transient current flowing when the voltage is applied.