JPH05196296A - Heater for bathtub water - Google Patents

Abstract

PURPOSE:To obtain an electric heater which has no danger of leak, is safe and has a low cost and a large capacity for a purifying device of bathtub water. CONSTITUTION:A insulation deterioration degree sensor 8 for periodically sensing presence or absence of a malfunction of insulation deterioration degree of an outside of a double sheathed heater 12 is disposed. The sensor 8 has an insulation deteriorating degree sensor 9 for sensing insulation deterioration of the sensor 8 and a self-diagnosing circuit 10 for diagnosing a conduction malfunction of the sensor 9. Since insulation deterioration degree of the heater 12 can be periodically checked, a heater having a large capacity and connected directly to a commercial power source can be used without anxiety of a danger of leak.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath water device, and more particularly to an electric heating device of a cleaning device arranged in a circulation path for forcibly circulating bath water by a circulation pump.

[0002]

2. Description of the Related Art Currently, bath water is circulated by a circulation pump,
A bathtub sterilizer equipped with a purifier that purifies by filtering, sterilizing, etc. was developed along the route, and this purifier was equipped with a heating device to keep the bath water at an appropriate temperature continuously and to be comfortable all day long. Something that can be bathed is being developed.

[0003]

2. Description of the Related Art In a bath water heating device using multiple sheath heaters, multiple sheaths are provided in order to prevent accidents of leaking electricity to the bath water in advance when the sheath heater has a hole and the insulation is in a poor state. For the outermost insulation layer of the heater,
An insulation deterioration degree detection device was installed, and when measuring insulation deterioration degree, it was connected to a sheathed heater, and if an insulation resistance was measured and an abnormality was detected, the abnormality was displayed without turning on the sheathed heater.

However, if the insulation deterioration degree detecting device which should have been connected to the sheathed heater becomes defective due to some reason, the insulation resistance of the sheathed heater is abnormal even if the insulation of the sheathed heater is deteriorated. Not only will not be recognized, but there is a possibility of false detection.

[0005]

SUMMARY OF THE INVENTION That is, the present invention is directed to a device for detecting the degree of insulation deterioration of the outermost powdery layer of electrically insulating material of a multiple sheath heater, and a connection failure between the device for detecting insulation degradation and the sheath heater. A detection device composed of a conduction failure detection device for detecting, an insulation transformer device for insulating the power supply of this detection device from a commercial power source, and a detection device switch for switching the insulation deterioration degree detection device of the detection device and the conduction failure detection device Device, a detection device circuit disconnection device for connecting the detection device to the sheath heater only when measuring, and a sheath heater on / off device that intervenes between the sheath heater and the commercial power supply to switch the sheath heater on and off. The display device that sometimes displays an abnormality and each information is input from the detection device to display the abnormality on the display device and control the cutting device with the sheath heater. This heating device of the bath water, characterized in that it comprises a control device.

[0006]

When the disconnection of the lead wire, the disconnection of the connection portion, the contact failure of the relay which is turned on to detect the degree of insulation deterioration, or the like causes the conduction failure between the sheathed heater and the insulation deterioration degree detection device, Since conduction failure can be detected,
The insulation deterioration degree was measured without noticing the poor continuity, the insulation deterioration degree was judged to be above the reference value even though there was a hole in the sheath of the sheathed heater, and there was no problem.
It is possible to prevent electric shocks from occurring by leaking electricity to the bathtub water etc.

[0007]

EXAMPLE FIG. 1 is a basic block diagram of the present invention. A double sheathed heater is used as the electric heater, and an insulation deterioration degree detection device 11 for detecting the insulation degree of the outer electric insulating material powder layer by measuring the insulation resistance and a continuity failure detection device 12 for checking the continuity of the connection. Detection device 14 consisting of two devices
However, based on the control of the control device 10, the connection between both
It is connected to a double sheathed heater via a detector disconnection device 9 which turns off and on. I will.

Further, the detection device 14 is also the control device 1.
By the detection device switching device 13 controlled by 0,
Which of the insulation deterioration degree detection device 11 and the conduction failure detection device 12 is made to function is selected. The information obtained by the detection device 14 is sent to the control device 10, and if the result is judged to be abnormal, the error is displayed on the display device 15.

The control by the control device 10 for detecting the degree of insulation deterioration after confirming whether or not there is a conduction failure in the detection device 14 is performed by a program stored in a program ROM as shown in the flowchart of FIG. Is done. First, as the first step, for example, the insulation degree is detected every 24 hours, and it is checked whether or not 24 hours have elapsed from the previous measurement. If 24 hours have elapsed, the second sheath heater 8 is connected to the second step as a second step. Turn off the power of the heater by the heater-on / off device 2 to turn on / off the power.

This is to prevent the commercial power supply 1 from flowing into the detection circuit 14 in the unlikely event that the heating wire 16 of the double sheathed heater 8 and the first metal pipe 17 have defective insulation. After that, as a third step, the detection device circuit disconnecting device 9 is turned on to connect the double sheath heater 8 and the detection device 14. Next, in the fourth step, the conduction failure detection device 12 is first selected from the detection devices 14 by the detection device switching device 13, and in the fifth step, the connection between the insulation deterioration degree detection device 11 and the double sheathed heater 8 is connected. Measure

As a sixth step, it is judged whether or not the measurement result is poor continuity, and if the result is poor continuity, as a seventh step, it is displayed on the display device 15 that the continuity is poor, and the control is terminated. .. When it is determined in the sixth step that there is no conduction failure, the detection apparatus switching apparatus 13 insulates the detection apparatus 14 connected to the double sheath heater 8 from the conduction failure detection apparatus 12 this time as an eighth step. Switch to the deterioration detection device 11.

As a ninth step, the degree of insulation deterioration of the double sheathed heater 8 is measured. It is determined whether the insulation degree detected as the 10th step is a certain value or more, and if it is less than the certain value, the display device 1 is set as the 11th step.
The heater error is displayed on 5. When the value is equal to or more than the predetermined value, the detection device circuit disconnecting device 9 is turned off and the double sheathed heater 8 and the detection device 14 are disconnected as a twelfth step. Then, as the 13th step, the heater power is turned on again by the heater switching device 2 and the next detection time is waited for.

The control of the double-sheath heater 8 is such that the control device 21 controls the detection device 14 to be connected to the double-sheath heater only when detecting the conduction failure or the degree of insulation deterioration.
This is to prevent the insulation transformer device 3 from suffering an electric shock if there is a continuous flow of current, and to prevent the electric shock from occurring in the metal pipe of the double sheathed heater 8 and the destruction of the insulation caused by the electric contact.

FIG. 2 shows the basic block diagram of FIG. 1 as a circuit diagram, and the details will be described below with reference to this diagram. First, the control device power supply device 6 and the detection device power supply 7
These devices are isolation transformer devices 3
Replace the AC power supply that has been reduced to a predetermined voltage with DC by rectifying diodes 6a and 7a, and smooth the ripple of the DC power supply with capacitors 6b and 7b.

After that, the voltage is stabilized by the constant voltage devices 6c and 7c, and each power source for the control device Vcc and the detection device VD is produced. In the double sheathed heater 8, the heating wire 16 is connected to the contact 2a of the double cut relay RY2 as the heater enclosing cut device 2, and detects the insulation resistance of the second insulating material powder layer 18 which is the outer insulating layer. The two lead wires 20a and 21a conducted to the first and second metal pipes 17 and 19 which are conductors opposed to each other with the insulating layer 18 sandwiched therebetween are contact points of the double-cut relay RY1 serving as the detection device circuit disconnecting device 9. 9
It is connected to a.

If the lead wires 20a and 21a are connected to the metal pipes on one side of the heating wire outlets at the two locations of the double sheath heater 8, the lead wires 20b and 21b are connected to the metal pipes on the opposite side. , A double-sided relay RY3 as the detection device switching device 13
It is connected to the contact 13a of.

The detection device 14 includes a continuity failure detection device 12 and
The insulation deterioration degree detecting device 11 is used, and common circuit portions of both detecting devices are represented by 22a to 22d. First, the comparator 22a includes a lead wire 20a directly connected to the metal pipe of the double sheathed heater 8 and 21a via 20b and 21b connected by relay contacts.
To the second, and secondly the insulation resistance of the outer insulating layer 18,
Each is detected as a voltage and compared with a reference value. that time,
A high level signal is output when the compared voltage is below the reference value, and a low level signal is output when the compared voltage is above the reference value.

Further, the detection device 14 is provided with a photocoupler 22b which once converts the signal output from the comparator 22a into an optical signal and then converts the signal into an electric signal and sends the electric signal to the microcomputer 23a. And the power supply VD for the detection device are not mixed, and the commercial power supply 1 and the insulation transformer device 3 insulate the control device 10 that is not double-insulated from the detection device to improve safety.

The control device 10 includes a microcomputer 23a, a transistor 10b for operating the relay RY2 as the heater enclosing switching device 2 in response to a signal from the microcomputer 23a, and a detection device circuit disconnecting device 9.
10c for activating the relay RY1 as a relay, and a relay RY as the detection device switching device 13
Transistor 10d etc. for activating 3 are provided.

Explaining the operation of the circuit as described above, the microcomputer 23a operates by the power supply Vcc, and outputs a low level signal to the transistor 23b at the time of detection to turn off the transistor 23b. As a result, the current in the coil 2b of the relay RY2 serving as the heater switching device 2 is cut off, the contact 2a is opened, and the heating wire 16 of the double sheath heater 8 and the commercial power supply 1 are disconnected.

After that, the microcomputer 23a outputs a high level signal to the transistor 23c and turns on the transistor 10c. As a result, a current flows through the coil 9b of the relay RY1 as the detection device circuit disconnecting device 9, the contact 9a is closed, and lead wires 20a and 21a connected to the metal pipe on one side of the double sheathed heater 8 are provided.
The detection device 14 is connected.

Further, the microcomputer 10a is
A high level signal is output to the transistor 10b and the transistor 10d is turned on. As a result, a current flows through the coil 13b of the relay RY3 as the detection device switching device 13, the contact 13a is closed, and the lead wires 20b and 2 connected to the metal pipe on the other side of the double sheath heater 8 are connected.
1b are connected to each other to reach the lead wire 20b from the lead wire 20a through the first metal pipe 17, and the lead wire 2 is connected to the lead wire 20b through the second metal pipe 19.
A conduction failure detecting path reaching 1a is formed, and the conduction failure detecting resistor 12a as the conduction failure detecting device 12 is connected to the insulation deterioration degree detecting resistor 1 as the insulation deterioration degree detecting device 11.
Connect in parallel with 1a.

This is because the resistance value of the conduction failure detecting resistor 12a is made considerably lower than the resistance value of the insulation deterioration degree detecting resistor 11a, so that the detection relay contacts 9a and 13a are relatively large when the conduction failure is detected. This is because the contacts are cleaned by passing an electric current. With the above, first, the conduction failure detection device 12 of the detection device 14 is selected.

In the conduction failure detection path described above, the potential on one side is GND and the potential on the other side is VB, and VB is connected to the power supply VD via the resistor connected earlier. If the continuity failure detection path is maintained conductive, VB becomes the GND level, which is lower than the reference voltage VA preset by using the resistors 14c and 14d. Therefore, the comparator 14a using VB as an input is It outputs a high level signal and turns on the photo coupler 14b.

When the photo coupler 14b is turned on, the control device 1
A low level signal of the microcomputer 10a of 0 is input, and the contact of the relay is turned on to detect the degree of insulation deterioration of the double sheathed heater 8. The contact of the contact is broken, the lead wire is disconnected, and the connection is defective. It is detected that there is no defective conductor wire.

If a relay contact failure, a lead wire break, or a contact failure at the connecting portion of the relay occurs, the impedance of the conduction failure detection path is equal to that of the conduction failure detection resistor 12a connected in parallel with each other. Compared with the combined impedance with the insulation deterioration detection resistor 11a, it gradually becomes higher, and VB becomes a higher potential than VA.

As a result, the comparator 14a outputs a low level signal, turns off the photocoupler 14b, and outputs a high level signal to the microcomputer 10a to detect that a conduction failure has occurred. As a result, the microcomputer 10a sends information to the LCD driver 15a as the display device 15 and causes the LCD 15b to display that there is a poor conduction.

When it is detected that the device connected to detect the degree of insulation deterioration has no conduction failure, the microcomputer 10a outputs a low level signal to the transistor 10d and turns off the transistor 10d. As a result, the current of the coil 13b of the relay RY3 as the detection device switching device 13 is cut off, the contact 13a is opened, the conduction failure detection path is cut, and the conduction failure detection resistor 12a is also disconnected from the detection device 14, Detector 14
Of these, the insulation deterioration detection device is selected.

When detecting the degree of insulation deterioration, first the first metal pipe 1 is sandwiched by sandwiching the insulating layer outside the double sheathed heater 8.
The lead wire 20a connected to 7 passes through VB to the insulation deterioration degree detecting resistor 11a connected to VD on the opposite side,
The lead wire 21a connected to the second metal pipe 19 is also connected to GND through the contact 9a of the relay RY1. Then, the potential of VB which changes according to the change of the insulation resistance of the insulating layer 18 is used as a comparator 14a having VB as an input.
However, it detects the degree of insulation deterioration by comparing it with the VA potential described above.

If the insulating layer 18 of the double sheathed heater 8 is destroyed and the insulation resistance is lowered and VB becomes lower than VA, the comparator 14a outputs a high level signal,
The photocoupler 14b is turned on. Photo coupler 14b is O
Then, a low level signal is input to the microcomputer 10a of the control device 10 to detect that insulation deterioration has occurred.

As a result, the microcomputer 10a
Information is sent to the LCD driver 15a serving as the display device 15 to cause the LCD 15b to display that insulation deterioration has occurred.
When insulation deterioration does not occur, the voltage VB is higher than the voltage VA, the comparator 14a outputs a low level signal, the photocoupler 14b is turned off, and the microcomputer 1
A high level signal is input to 0a, and the double sheath heater 8
It can be detected that the insulation layer 18 has no insulation deterioration.

When it is detected that the insulation has not deteriorated, the microcomputer 10a detects the transistor 10
A low level signal is output to c to turn off the transistor 10c. As a result, the current to the coil 9b of the relay RY1 as the detection device circuit disconnecting device 9 is cut off, the contact 9a is opened, and the lead wires 20a and 21a connected to the metal pipe on one side of the double sheathed heater 8 and the detection device. The connection with 14 is disconnected.

Then, this time, the microcomputer 1
A high level signal is output from 0a to the transistor 10b to turn on the transistor 10b. When the transistor 10b is turned on, a current flows through the coil 2b of the relay RY2 as the heater switching device 2, the contact 2a is closed, and the double sheath heater 8 is turned on by connecting the current line 16 and the commercial power supply 1.

Next, the structure of a double sheathed heater as a multiple sheathed heater will be described with reference to FIGS. 3 and 4. FIG. 3 shows a side view in which a part of the double sheathed heater 8 is shown as a cross section. 16 is a heating wire such as a nichrome wire, 36 is a first insulating powder layer for covering the heating wire 16, and 19 is this. The first metal pipe 18 that covers the first insulating material powder layer 36 is a second insulating material powder layer that covers the first metal pipe 17, and 19 is a second metal pipe that covers the second insulating material powder layer. Is double-insulated with insulating powder layers 36 and 18.

The insulating material powder layers 36 and 18 are formed of an electrically insulating metal oxide powder such as magnesium oxide, and the metal pipes 17 and 19 have strong mechanical strength such as SUS and copper and are resistant to corrosion. Although it is made of metal, the inner first metal pipe 17 does not require strength and corrosion resistance as compared to the outer second metal pipe 19, so the wall thickness can be reduced or a material with low corrosion resistance can be used.

Reference numeral 24 is a heater terminal having a threaded portion spot welded to the heating wire 16, and reference numerals 25 and 26 are insulating material powders 36 and 18 filling the end openings of the first and second metal pipes 17 and 19. Sealing material such as glass and silicone that seals the metal so that it does not leak, and 27 is a mounting flange that is mounted by fitting the second metal pipe to the threaded part.

FIG. 4 is a partial side view showing a state in which the heater is attached to the mounting plate on one side of the heating wire outlet of the double sheathed heater 8 at two locations. Mounting flange 27 on plate 28
After the flange part of is closely attached via the water leakage prevention packing 29, the second detection terminal is fitted with the heater mounting nut 30 and screwed on the screw part.

Reference numeral 31 is a first detection terminal, 32 is a spacer made of an insulating material such as ceramic or glass, and the first detection terminal 31 has the spacer 32 fitted to the open end of the first metal pipe 17. Then, the nut 33 is fitted on the threaded heater terminal 35 and screwed on. 34 is 100V fitted to the heater terminal 3
Alternatively, it is a power supply terminal that connects to a general commercial power supply such as 200V, and is pressed by a nut and screwed.

The double sheathed heater 8 constructed in this way
The insulation resistance of the second insulating material powder layer 18 which is the outer insulating layer and the conduction of its detection path are such that the first detection terminal conducted to the first metal pipe 17 and the second metal pipe 19 are conducted. 2 detection terminals and lead wires 20a, 21a and 2
0b and 21b are connected to the detector 14, and the measurement is performed as described above.

[Brief description of drawings]

 Figure 1. Basic block diagram of an embodiment Fig. 2. Circuit diagram of the embodiment FIG. Side view of double sheathed heater Figure 4. Double-sealed heater installation diagram Figure 5. Flow chart of detection

[Procedure amendment]

[Submission date] January 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Bath water heating device

[Claims]

[Detailed Description of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bathtub device, and more particularly,
For example, the present invention relates to an electric heating device of a cleaning device arranged in a circulation path for forcibly circulating bath water by a circulation pump as disclosed in Japanese Patent Laid-Open No. 4-66192.

[0002]

At present, forced circulating bathtub water in the circulation pump, filtered through the circulation pathway, bath equipment provided with a cleaning device for cleaning has been developed by the sterilization or the like, also in this cleaning device Some have also been developed that are equipped with a heating device to keep the bath water at an appropriate temperature constantly and to be able to take a comfortable bath at any time of the day.

In the above-mentioned cleaning device, as a heating device for heating the bath water so as to keep it at an appropriate temperature, the heating wire is embedded in a sheathed heater or a ceramic covered with a metal pipe filled with an electrically insulating ceramic powder. Electric heaters such as ceramic heaters are widely used because the device is compact and inexpensive and easy to control.

When the bath water is directly heated by an electric heater having such a single insulation, holes may be formed in the metal pipe covering the heating wire due to corrosion or the ceramic may be cracked.
It is very dangerous for bathers because there is a risk of electrical leakage in the bath water due to poor insulation.

Therefore, it is conceivable to use a multiple-type sheathed heater having multiple insulating layers, for example, a double sheathed heater having double insulating layers, but in this case as well, holes are formed in the outer metal pipe. If the outer insulation broke and the outer insulation broke, then it would be the same as the single insulation.Therefore, even with double insulation, there is no change in that there is a risk of electrical leakage, as the insulation breaks only slightly longer. Is the same even if the number of insulating layers is further increased.

In order to prevent such a risk of leakage, an outer insulating layer of the multiple sheath heater is used as an insulating deterioration detecting insulating layer, and an insulating deterioration detecting circuit is connected to the insulating layer at a predetermined interval. There is also a device that detects the presence or absence of abnormality by measuring a characteristic indicating the degree of insulation deterioration such as the insulation resistance of the insulating layer.

[0007]

However, even if the insulation deterioration degree of the insulation layer is detected by the insulation deterioration degree detection circuit, the connection circuit between the detection circuit and the heater has a poor conduction due to a connection failure to the connection terminal or the like. In this case, even if the insulation of the insulating layer is deteriorated, it is erroneously detected that the degree of insulation deterioration is not abnormal, which is very dangerous.

The present invention solves the above-mentioned drawbacks of the prior art and prevents the insulation deterioration of the electric insulation layer from being erroneously detected due to poor conduction between the insulation deterioration detection circuit and the heater. An object of the present invention is to provide a multiple-type sheathed heater provided with an insulation deterioration degree detection device having high properties as a bath water heating device.

[0009]

That is, according to the present invention, a multi-sheath type electric heater having a plurality of electrically insulating layers filled with an electric insulating material to form a plurality of electric insulation layers is provided. In the bath water heating device deployed in the road,
Insulation including an insulation deterioration degree detection circuit for detecting the insulation deterioration degree of the insulation deterioration degree detecting electric insulation layer for the heater, and a self-diagnosis circuit for detecting a conduction failure between the insulation deterioration degree detection circuit and the heater. It is a bath water heating device characterized by being equipped with a deterioration degree detection device.

[0010]

The present invention is constructed as described above, and since the heater is of the multi-sheath type in which the heating wire is insulated by the multiple electrically insulating layers through the multiple electrically conductive coating tubes, the outer electrically conductive coating is provisionally provided. Even if a hole is made in the tube and the bath water penetrates and the insulation layer gets wet and the insulation is destroyed, the heating wire is still sufficiently filled with the insulation layer existing inside the destroyed insulation layer through the conductive cladding. Since it is insulated and does not leak electricity immediately, it is very safe.

Further, since the insulation deterioration degree detecting device for detecting the insulation deterioration degree of, for example, the outermost insulation insulation degree detecting electric insulation layer of the multiple electric insulation layers is provided for the heater, the control is performed. The device detects the degree of insulation deterioration at predetermined intervals, and if an abnormality is detected in this detection result, the heater can be turned off and the abnormality can be displayed, so that the abnormality can be found quickly and appropriate measures can be taken quickly. Very safe.

Further, the insulation deterioration degree detecting device is used not only for diagnosing the insulation deterioration degree detecting circuit for simply detecting the insulation deterioration degree but also for diagnosing the conduction failure of the connection circuit connecting the detection circuit and the heater. Since a self-diagnosis circuit of is also provided, it is possible to check the conduction deterioration between the insulation deterioration degree detection circuit and the heater.
For example, it is possible to appropriately check based on the control of the control device such that the check is always performed immediately before the detection of the insulation deterioration degree.

[0013] As a result, there is a concern that the electrical connection between the insulation deterioration detection circuit and the heater may be defective and that the insulation layer is not deteriorated even though the insulation layer is actually deteriorated. Since the insulation deterioration degree detecting device has high reliability, it is possible to completely prevent the electric leakage of the heater.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a basic block diagram showing the basic structure of the present invention. As an electric heater of the multiple sheath type,
The structure uses a double sheathed heater 12 having a double electric insulating layer, which will be described in detail later with reference to FIGS. 3 and 4. The double sheathed heater 12 is a double-sided heater that can completely cut off the supply of power. It is connected to the commercial power supply 1 via the on / off device 13.

Reference numeral 8 denotes an outer electric insulating layer of the two electric insulating layers of the double sheathed heater 12, which is an electric insulation layer for measuring insulation deterioration degree, and is insulated by measuring the electric insulation degree by, for example, insulation resistance. Double sheathed heater 1 to detect the degree of deterioration
It is an insulation deterioration degree detecting device connected to No. 2.

The insulation deterioration degree detecting device 8 comprises an insulation deterioration degree detecting circuit 9 and a self-diagnosis circuit 10. The insulation deterioration degree detecting circuit 9 is a circuit for measuring the insulation degree of an insulating layer as, for example, an insulation resistance. The double sheathed heater 12 is connected to the double sheathed heater 12 through two connecting terminals provided on an inner and outer metal pipe which is a conductive coating tube in which an electric insulating layer for measurement is interposed, or a conductive member with the metal pipe. ..

Numeral 11 indicates that the connection between the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 is O based on the control of the controller 7.
This is a detection device circuit disconnection device that is interposed between the connection lines for turning off and on.

When the detection device circuit disconnecting device 11 is interposed between the insulation deterioration degree detection circuit 9 and the double sheath heater 12, the double sheath heater 12 is used only for detecting the insulation deterioration degree. Since an electric current will flow, there is no possibility that electric current will leak to the bath water due to the detected electric current, or that the metal pipe of the heater will be pitted due to electrolytic corrosion.

The self-diagnosis circuit 10 is a circuit for diagnosing conduction between the insulation deterioration degree detection circuit 9 and the double sheath heater 12, and, like the insulation deterioration degree detection circuit 9, metal inside and outside the double sheath heater 12. The pipe or this conductive member is connected at a position different from the insulation deterioration degree detection circuit 9.

The self-diagnosis circuit 10 is openable and closable under the control of the control device 7, and is normally connected to the insulation deterioration degree detection circuit 9 via a double sheath heater 12 in a state where the circuit is open. However, when diagnosing a conduction failure, the circuit is closed, and the line for detecting a conduction failure in the connection line between the insulation deterioration degree detection circuit 9 and the double sheathed heater is closed to pass a diagnostic current. At the same time that the circuit is formed, a power supply for supplying a diagnostic current to this circuit is connected.

Double sheathed heater 12 of self-diagnosis circuit 10
The connection location to the insulation deterioration degree detection circuit 9 is made different from the connection location to the double sheathed heater 12 where the insulation deterioration degree detection circuit 9 is likely to cause a conduction failure. To do so.

Reference numeral 2 denotes an insulation transformer device. This insulation transformer device 2 changes the commercial power supply 1 to a predetermined voltage for operating the control device 7 and the insulation deterioration degree detection device 8 and at the same time secures these devices. In order to insulate from the commercial power supply 1 for this purpose, it comprises a control device insulation transformer 3 for the control device 7 and a small capacity detection device insulation transformer 4 for the insulation deterioration degree detection device 8.

When the insulation transformer device 2 is divided into the control device 7 and the insulation deterioration degree detecting device 8 in this way, the electric power used by the insulation deterioration degree detecting device 8 is smaller than the electric power used by the control device 7. As the insulating transformer 3 for the detection device, a small-capacity one suitable for the amount of power used can be used, which is convenient.

Further, since the insulation deterioration degree detecting device 8 supplies an electric current to the double sheathed heater 12 which comes into contact with the bath water at the time of detecting the insulation deterioration degree, there is a fear of an electric leakage at this time, and the risk of this electric leakage is more certain. To prevent this, the detector isolation transformer 4 was connected to the control device isolation transformer 3 and connected in series.
It has a double insulation structure in which it is connected to the commercial power supply 1 via an insulation transformer of the stand.

Reference numerals 5 and 6 are power supply devices for the control device and the detection device for supplying power to the control device 7 and the insulation deterioration degree detection device 8 by changing the alternating current to the direct current or stabilizing the voltage. ..

When the control device 7 and the insulation deterioration detection device 8 operate on alternating current, the power supply devices 5 and 6 for the control device and the detection device are of course unnecessary, and the insulation is very reliable. When a transformer is used, it is not necessary to double-insulate the insulation deterioration degree detection device 8 with the commercial power source 1 and the two isolation transformers 3 and 4, as described above.

The control device 7 is an R as a data storage device.
The microcomputer mainly comprises an OM, a CPU as an arithmetic unit, a program ROM storing an execution program for arithmetic processing, and a RAM as a temporary storage unit. The control unit 7 controls the entire device. Done.

Reference numeral 14 is a display device for displaying an abnormality such as a conduction failure between the insulation deterioration degree detection circuit 9 of the insulation deterioration degree detection device 8 and the double sheath heater 12 or a insulation failure of the electric insulation layer of the double sheath heater 12. Is.

The control for detecting the degree of insulation deterioration by the controller 7 is performed by a program stored in a program ROM as shown in the flow chart of FIG.

As the first step S1, for example, once a day, the insulation degree is detected every 24 hours, and it is checked whether or not 24 hours have passed since the previous measurement. If 24 hours have passed, the second step S2 is performed. As a cutting device with heater 13
The power of the double sheath heater 12 is turned off by.

In this way, the heater power is turned off prior to the detection of the insulation deterioration degree, because if the insulation of the heating wire is defective, the detection circuit from the commercial power supply 1 will detect the insulation deterioration degree. This is because an electric current may flow into the water in the bathtub and the detection circuit may be broken.

Further, since the insulation resistance value of the electric insulation layer changes depending on the temperature, it is more accurate to measure the insulation resistance after cutting the heater and lowering the temperature of the electric insulation layer.

As the third step S3, the detector circuit disconnecting device 11 is turned on to connect the double sheath heater 12 and the insulation deterioration degree detecting circuit 9 of the insulation deterioration degree detecting device 8.

Next, in a fourth step S4, the self-diagnosis circuit 10 is turned on and closed, and the connection line of the insulation deterioration degree detection circuit 9 and the double sheath heater 12 which is to be diagnosed for conduction failure is closed. At the same time as forming a circuit for diagnosing conduction failure that allows a diagnostic current to flow, a power source for the diagnostic current is connected to this circuit.

As a fifth step S5, a diagnostic current is passed through the conduction failure diagnosing circuit, and as a sixth step S6 it is detected whether or not a diagnostic current is flowing through the conduction failure diagnosing circuit to self-diagnose the conduction failure. When the conduction failure is diagnosed, the seventh step S7 is displayed on the display device 14 to indicate that the conduction failure is present, and the insulation deterioration degree detection program is terminated.

When the diagnosis of the continuity failure of the connection line connecting the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 is individually performed for each line, the fourth step S4 to the sixth step S6 are repeated. Needless to say.

When it is diagnosed that the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 are not defective in conduction as a result of the self-diagnosis, the self-diagnosis circuit 10 is turned off and the circuit is opened in the eighth step S8. After that, as the ninth step S9, the insulation deterioration degree detection circuit 9 detects the insulation deterioration degree by measuring, for example, the insulation resistance of the electric insulation layer for measuring the insulation deterioration degree of the double sheath heater 12.

In the tenth step S10, if it is judged that the insulation degree of the electric insulation layer is less than the reference value and the insulation is deteriorated, the first step is performed.
In step S11, the display device 14 displays that the insulation is deteriorated, and the insulation deterioration degree detection program ends.

On the other hand, if it is determined in the tenth step S10 that the insulation degree of the electrical insulation layer is equal to or higher than the reference value and the insulation is not deteriorated, the detection device circuit disconnecting device 11 is turned off in the twelfth step S12. Double sheath heater 1
2 and the insulation deterioration degree detection circuit 9 are disconnected, and as the thirteenth step S13, the heater enclosing / switching device 13 causes the electric current from the commercial power source 1 to flow through the double sheath heater 12 to start the heating of the bath water again. Wait until the insulation degradation detection time is reached.

FIG. 2 shows a basic block diagram of FIG. 1 as a circuit diagram, and the details of the embodiment will be described based on this diagram.

First, the power supply device 5 for the control device and the power supply device 6 for the detection device will be described. In these devices, the AC power supply reduced to a predetermined voltage by the insulating transformer device 2 is converted into direct current by the rectifying diodes 5a, 6a. Then, the ripple of the direct current power supply is smoothed by the capacitors 5b and 6b,
After that, it is stabilized by the constant voltage devices 5c and 6c, and V for controller is used.
cc and VD for detection device are made to be power sources.

In the double sheathed heater 12, the heating wire 15 is a double-sided relay RY2 as the heater-incorporated cutting device 13.
Connected to the two contacts 13a and 13b of the
Also, the outer second electric insulating layer 18 of the second electric insulating layers 16 and 18 is used for measuring the insulation deterioration degree, and the second electric insulating layer 18 is opposed to the second electric insulating layer 18 in order to detect the insulation resistance of the electric insulating layer. First and second metal pipes 17 and 1 which are conductors
Two lead wires 32 and 33 extend from 9 or this conductive member.

Reference numeral 11 denotes a double-sided relay RY1 as a detector circuit disconnecting device, and at the same time as the lead wires 32 and 33 from the double sheathed heater 12 are connected to the two contacts 11a and 11b of the relay RY1. Is connected to the comparator 9a of the insulation deterioration degree detection circuit 9, and the comparison current lead wire 9j is connected to the other contact 11a.
A ground wire 9k is further connected to the insulation deterioration detection circuit 9 and the double sheathed heater 12.

The insulation deterioration detection circuit 9 is provided with a comparator 9a for detecting the insulation resistance of the second electric insulation layer 18 of the double sheathed heater 12 as a voltage and comparing the detected voltage with a reference value. The comparator 9a, when diagnosing a conduction failure between the insulation deterioration degree detection circuit 9 and the double sheathed heater 12, performs a diagnosis conducted to a conduction failure diagnosing circuit formed by closing a connection line for diagnosing the conduction failure. The presence / absence of current flow is detected as a voltage, and the detected voltage is compared with a reference value to diagnose the presence / absence of conduction failure of the connection line.

The insulation deterioration degree detection circuit 9 is provided with a photocoupler 9b which once converts the signal output from the comparator 9a into an optical signal and then converts the signal into an electric signal and sends the electric signal to the microcomputer 7a. The Vcc and the power supply VD for the detection device are prevented from being mixed with each other, and the commercial power supply 1
The control device 7 which is not double-insulated by the insulation transformer device 2 is insulated from the insulation deterioration degree detection device 8 to improve safety.

Next, a description will be given of a configuration in which a connection failure diagnostic circuit for diagnosing a failure in conduction between the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 is closed to form a circuit for diagnosing a failure in conduction.
In the present embodiment, the conduction failure of the two connection lines connecting the insulation deterioration degree detection circuit 9 and the double sheathed heater is diagnosed simultaneously without diagnosing each of them.

From the first and second metal pipes 17 and 19 of the double sheathed heater 12 or the conductive member, they are provided at positions different from the contact points of the lead wires 32 and 33 connecting the insulation deterioration degree detection circuit 9. Two lead wires 34 and 35 for forming a conduction failure diagnosing circuit of lead wires 32 and 33 extend from the contact point.

Reference numeral 10 is a self-diagnosis circuit formed as a double-cut relay RY3 having two contacts 10a and 10b, and one contact 10a of the double-cut relay RY3 has two double sheath heaters 12 connected thereto. Lead wire 34
, 35, and the other contact 10b, the insulation deterioration degree detection current lead wire 9c and the self-diagnosis current lead wire 9e of the insulation deterioration degree detection circuit 9 for supplying a diagnosis current to the conduction failure diagnosis circuit. Are connected.

The control device 7 includes a microcomputer 7
a, a transistor 7 for actuating a relay RY2 as the heater enclosing switching device 13, a relay RY1 as the detection device circuit disconnecting device 11, and a relay RY3 as the self-diagnosis circuit 9 in response to signals from the microcomputer 7a.
b, 7c, 7d are deployed

Further, the display device 14 is operated by a signal from the microcomputer 7a of the control device 7, and the LCD 14 is operated.
An LCD driver 14a for displaying an abnormality such as insulation deterioration and poor continuity is provided in b.

Explaining the operation of the circuit as described above, the microcomputer 7a operates with the power source Vcc,
When detecting the degree of insulation deterioration, first, a low level signal is output to the transistor 7b and the transistor 7b is turned off.
To do.

As a result, the current to the coil 13c of the relay RY2 as the heater switching device 13 is cut off, the contacts 13a and 13b are opened, and the heating wire 15 of the double sheathed heater 12 and the commercial power source 1 are completely disconnected. Be drunk

Then, a high level signal is output to the transistors 7c and 7d to turn them on, and a current is passed through the coil 11c of the relay RY1 as the detection device circuit disconnecting device 11 and the coil 10c of the relay RY3 as the self-diagnosis circuit 10. The contacts 11a and 11b of RY1 and the contacts 10a and 10b of the relay RY3 are closed.

In this way, the detection device circuit disconnecting device 11
Since the contact of the self-diagnosis circuit 10 is closed, the contact 11 of the relay RY1 is connected to the lead wire 9j for inputting the comparator.
b, lead wire 33, first metal pipe 17, lead wire 3
4, contact 10a of relay RY3, lead wire 35, second metal pipe 19, lead wire 32, contact 11 of relay RY1
A circuit is formed from a through to the ground wire 9k.

In this circuit, the lead wires 32 and 33 which are the connecting wires between the insulation deterioration degree detecting circuit 9 and the double sheath heater 12 are connected.
And are directly connected and closed via the first and second metal pipes 17 and 19 without passing through the electrical insulation layer 18 for measuring the degree of insulation deterioration, and conduction can be simultaneously diagnosed for a conduction failure of two connection lines. It is a circuit for fault diagnosis.

Further, in the conduction failure diagnosing circuit formed as described above, the insulation deterioration degree detecting current lead wire 9 is provided.
c is connected to the self-diagnosis current lead wire 9e, the currents from the lead wires 9c and 9e are passed through the circuit as a diagnostic current, and whether the circuit is defective or not is diagnosed by the presence or absence of the flow of this current. To do.

It is to be noted that, in order to diagnose the conduction failure, the current from the lead wire for self-diagnosis degree detection 9e in addition to the current from the lead wire for insulation deterioration degree detection current 9c is caused to flow through the circuit. A large resistor 9d commensurate with the resistance of the electric insulation layer is provided on the line 9c, and only a weak current flows and a failure in conduction cannot be completely diagnosed. Therefore, a self-diagnosis current lead provided with a small resistor 9f is provided. This is because a large current needs to flow from the line 9e, and the relay contact can be cleaned by flowing a large current.

When a diagnostic current is applied to the conduction failure diagnosing circuit closed by the self-diagnosis circuit 10 described above, if there is no conduction failure in the circuit, this circuit is grounded by the ground wire 9k. Since VB becomes the GND level and is lower than the reference voltage VA preset by using the resistors 9h and 9i, the comparator 9a outputs a high level signal and turns on the photocoupler 9b.

When the photocoupler 9b is turned on, a low level signal is input to the microcomputer 7a of the control device 7, and the metal pipes 17 and 1 of the lead wires 32 and 33 are input.
It is diagnosed that the connection line between the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 including the contact point 9 does not have a conduction failure.

Of course, by diagnosing the poor continuity of the connecting line,
Since the presence / absence of abnormality of the entire circuit for diagnosing conduction failure is diagnosed, the presence / absence of abnormality of the insulation deterioration degree detection device 8 itself is also diagnosed at the same time.

On the other hand, when the conduction failure diagnosis circuit has a conduction failure, the ratio of the resistance of the conduction failure portion to the combined resistance of the resistors 9d and 9f connected in parallel to the conduction failure diagnosis circuit. The voltage VB determined by is higher than the reference voltage VA.

As a result, the comparator 9a outputs a low level signal to turn off the photocoupler 9b, outputs a high level signal to the microcomputer 7a, and a conduction failure occurs between the insulation deterioration degree detection circuit and the double sheathed heater. Diagnose that it is occurring.

When the microcomputer 7a diagnoses that there is a conduction failure, it sends a signal to the LCD driver 14a of the display device 14 to cause the LCD 14b to display that there is a conduction failure.

If the self-diagnosis described above determines that the circuit for detecting the degree of insulation deterioration does not have a conduction failure, the microcomputer 7a outputs a low level signal to the transistor 7d and turns it off.

As a result, the current to the coil 10c of the relay RY3 as the self-diagnosis circuit 10 is cut off and the contact 1
0a and 10b open, the first and second metal pipes 17
, 19 and the lead wires 32 and 33 are disconnected, and at the same time, the self-diagnosis current lead wire 9e is also disconnected from the comparator input lead wire 9j. Double sheathed heater 1 via leads 32 and 33
The circuit state of the insulation deterioration degree detection is shown in which the circuit is connected to the electrodes sandwiching the electric insulation layer 2 for insulation deterioration degree measurement.

When detecting the degree of insulation deterioration, from the comparator input lead wire 9j to the contact 11b of the relay RY1, the lead wire 33, the first metal pipe 17, the second electric insulation layer 18, the second wire
Metal pipe 19, lead wire 32, relay RY contact 11
A circuit for detecting the degree of deterioration of insulation, which extends from a to the ground wire 9k, is formed, and the lead wire 9j for inputting the comparator of this circuit is formed.
The VD power source is connected to the insulation deterioration degree detection current lead wire 9c provided with the resistor 9d.

In this circuit, the second electrically insulating layer 18
Since the voltage VB changes when the insulation resistance of No. 2 changes, the voltage VB is compared with the reference voltage VA described above by the comparator 9a to detect the degree of insulation deterioration of the second electric insulation layer 18.

When the second electric insulating layer 18 is not deteriorated and the insulation resistance is high, the voltage VB becomes high level and V
Since it becomes higher than A, the comparator 9a outputs a low level signal and turns off the photocoupler 9b.

When the photo coupler 9b is turned off, the control device 7
A high level signal is input to the microcomputer 7a of No. 2 and the second electric insulating layer 18 of the double sheathed heater 12 is detected to have no insulation deterioration.

In this way, when it is detected that the second electric insulation layer 18 of the double sheathed heater 12 is not deteriorated in insulation, the microcomputer 7a outputs a low level signal to the transistor 7c, and this transistor 7c is output.
Turn off.

When the transistor 7c is turned off, the coil 11 of the relay RY1 serving as the detection device circuit disconnecting device 11
The current to c is cut off and the two contacts 11a and 11b
Open and the connection between the insulation deterioration degree detection circuit 9 and the double sheathed heater 12 is released.

After that, a high level signal is output from the microcomputer 7a to the transistor 7b, the transistor 7b is turned on, a current is supplied to the coil 13c of the double-cut relay RY2 as the heater enclosing device 13, and the contact 1
Close 3a and 13b.

As a result, the heating wire 15 of the double sheathed heater 12 is connected to the commercial power source 1, and the heating of the bath water is restarted.

On the other hand, when the second electric insulation layer 18 of the double sheathed heater 12 is destroyed and the insulation resistance is lowered, the voltage VB becomes lower than the reference voltage VA, and the comparator 9a outputs a high level signal and the photo coupler. 9b is turned on and a low level signal is output to the microcomputer 7a of the control device 7 to detect that insulation deterioration has occurred.

As a result, the microcomputer 7a sends a signal to the LCD driver 14a of the display device 14, and LC
It is displayed on D14b that insulation deterioration has occurred.

Next, the structure of the double sheathed heater 12 as the multiple sheathed heater will be described with reference to FIGS.

FIG. 3 is a side view showing a part of the double sheathed heater 12 as a cross section, wherein 15 is a heating wire such as a nichrome wire, and 17 is a multiple conductive cladding tube covering the heating wire 15. Of the first metal pipe, 16 is a first electric insulating layer formed by filling the voids of the first metal pipe 17 with an electric insulating material powder, and 19 is a first electrically conductive cladding that covers the outside of the first metal pipe 17. 2 metal pipe, 18 is second metal pipe 19
Is a second electric insulation layer formed by filling the voids with electric insulation powder, and the heating wire 15 is double insulated by the first electric insulation layer 16 and the second electric insulation layer 18.

The electrically insulating material powder that fills the voids of the first and second metal pipes 17 and 19 as the electrically conductive coating tube to form the electrically insulating layers 16 and 18 is an electrically insulating powder such as magnesium oxide. A metal oxide powder is used, and for the metal pipes 17 and 19, a metal such as SUS or copper having high mechanical strength and corrosion resistance is used.
The first metal pipe 17 on the inner side is the second metal pipe 1 on the outer side.
9 does not require strength and corrosion resistance, so it is possible to reduce the wall thickness and use a material having low corrosion resistance.

Reference numeral 20 is a heater terminal having a threaded portion spot-welded to the heating wire 15, 21 and 22 are electric insulating layers 16 at the end openings of the first and second metal pipes 17, 19.
Glass, a sealing material such as silicone rubber, which blocks the insulating powder filled in the voids to form 18 so as not to leak, and 23 is a mounting flange that is mounted by fitting the second metal pipe 19 with a screw portion. is there.

FIG. 4 is a partial side view showing a state where the heater is attached to the attachment plate.
No. 2 is attached by fitting the flange portion of the mounting flange 23 to the heater mounting plate 24 via the water leakage prevention packing 25, and then fitting the heater mounting nut 26 to the screw portion and screwing.

27 is a lead wire 33 on the first metal pipe 17.
Is a first insulation resistance measurement terminal for connecting the first insulation resistance measurement terminal 27 with a spacer 28 made of an insulating material such as ceramic or glass at the open end of the first metal pipe 17. Then, the nut 29 is fitted and screwed to the heater terminal 20 which is threaded.

Reference numeral 30 designates 100 fitted in the heater terminal 20.
It is a power source terminal connected to a general commercial power source such as V or 200 V, and is pressed against the nut 29 by the nut 31 and screwed.

Reference numeral 36 denotes the second heater mounted on the heater mounting plate 24.
A second insulation resistance measuring terminal for connecting the lead wire 32 to the metal pipe 19, and a second insulation resistance measuring terminal 36.
Is attached to a conductive component directly attached to the second metal pipe 19 such as the attachment flange 23 in principle,
It goes without saying that the insulation resistance is not hindered even if it is attached to the heater attachment plate 24 that is in conduction with the second metal pipe 19 via the attachment flange 23.

The double sheathed heater 1 thus constructed
The first insulation resistance measuring terminal 27 in which the insulation resistance for detecting the degree of insulation deterioration of the second electric insulation layer 18, which is the outer electric insulation layer of 2, is conducted to the first metal pipe 17 as the conductive cladding tube. And the lead wires 33 and 32 from the second insulation resistance terminal 36 connected to the second metal pipe 19 are connected to the insulation deterioration degree detection circuit 9 and measured as described above.

Further, in the present invention, as described above, the circuit for self-diagnosing the conduction failure of the circuit for detecting the degree of insulation deterioration is provided, and the lead wires 34 and 35 for this purpose are provided.
Is connected to the first and second metal pipes 17 and 19, the first and second self-diagnosis terminals for this connection are not electrically connected to the insulation resistance terminals 27 and 36, though not shown. It is provided at the position where

[0087]

The present invention has the above-described structure and operation, and has a circuit structure in which there is almost no risk of electric leakage to the bath water, and whether or not there is an abnormality in the insulation of the electric insulation layer of the multiple sheathed heater. You can check constantly with high reliability.

As a result, the electric heater can be directly connected to the commercial power source without passing through the insulating transformer, and a compact, low-cost and highly safe large-capacity bath water heating apparatus can be easily provided.

The heating device of the present invention was designed for heating bath water, which requires a very high level of safety in order to protect the bather from the danger of electric shock. It has a great effect when used as a heating device for devices such as a washing machine and an ornamental fish breeder that are strongly required to prevent electric shock to the human body like bath water.

[Brief description of drawings]

FIG. 1 is a basic block diagram of an embodiment,

FIG. 2 is a circuit diagram of an embodiment,

FIG. 3 is a side view of the double sheathed heater,

FIG. 4 is a mounting diagram of a double sheath heater,

[Fig. 5] Flow chart of control of insulation deterioration degree detection device

[Explanation of Codes] 1 commercial power supply 2 insulation transformer device 5 power supply device for control device 6 power supply device for detection device 7 control device 8 insulation deterioration degree detection device 9 insulation deterioration degree detection circuit 10 self-diagnosis circuit 11 detection device circuit disconnection device 12 Double sheathed heater 13 Cutting device with heater 15 Heating wire 16 First electric insulating layer 17 First metal pipe 18 Second electric insulating layer 19 Second metal pipe

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

Claims (1)

[Claims] 1. A detection device comprising a first detection means for detecting a degree of insulation deterioration and a second detection means for detecting a conduction failure in a bath water heating device in a bathtub using a multiple sheath heater. An insulating transformer that insulates the power supply of the detection device from the commercial power supply, a switching device that switches between the first detection device and the second detection device, a detection device circuit disconnection device that connects the detection device to the electric heater, and a heater that connects and disconnects the electric heater. A bath water heating apparatus comprising: an opening / closing means, a display means for displaying an abnormality, and a control means for controlling a detection device circuit disconnection means.