JPH10262496A - Heater for glass tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater for glass tank which is effective for fishes for appreciation or the like by improving safety by cutting electrification to a heating body before the heater is turned to an abnormally high temperature by providing a subordinate heating body or the like for applying heat to a temperature fuse by heating together with a main geating body at the time of electrification. SOLUTION: This heater is provided with a bimetal type thermal protector 34 interposed between one end of a main heating body 26 and the other end of a connecting cord 30 so as to be turned on/off at an operating temperature due to air electrification, the temperature fuse 35 housed at another side part 16b in a housing space 16 and serially connected to the thermal protector 34 so as to cut the electrification by fusing at a set temperature higher than the operating temperature of the thermal protector 34, and a subordinate heating body 27 housed at the other side part 16b in the housing space 16 in the state of being pressed onto the inner face of a case 17, and serially connected to the main heating body 26 so as to apply heat to the temperature fuse 35 by heating together with the main heating body 26 at the time of electrification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for heating water in an aquarium for rearing ornamental fish and the like.

[0002]

2. Description of the Related Art As a conventional heating device for a water tank, for example, an elongated case having a storage space hermetically sealed therein and a storage case provided in one side of the storage space and generating heat when energized are provided. A heating element for heating water in the water tank and a power plug connected to a commercial power supply are provided at one end,
A connection cord whose other end is inserted into the storage space through the other end of the case is housed in the other side of the storage space, and is connected between one end of the heating element and the other end of the connection cord. There is known a device provided with a bimetallic thermal protector which is mounted and turned on and off when the operating temperature is reached by energization in the air.

If the heating device is accidentally taken out of the water tank to clean the water tank while power is supplied to the heating element, the case is surrounded by air that provides heat insulation. There is no place for heat to escape from the body, and the temperature of the case rises. When this heat heats the thermal protector to the shut-off operating temperature, the thermal protector is turned off and cuts off the power supply to the heating element. Thereafter, when the temperatures of the case and the thermal protector decrease to the return operation temperature, the thermal protector is turned on again, and the power supply to the heating element is restarted. Such an operation is repeatedly performed until the operator notices the abnormality and unplugs the power plug.

However, in such a case, when the thermal protector is repeatedly turned on and off as described above, the contacts of the thermal protector may be welded to cause a failure while the thermal protector remains on. When the heating device is energized in the air, the thermal protector does not switch off, so that the heating device rises to an abnormally high temperature due to heat from the heating element. Therefore, in order to prevent such a situation from occurring, a thermal fuse that blows at a set temperature higher than the operating temperature of the thermal protector is connected in series to the thermal protector,
It is conceivable that the thermal fuse is blown before the heating device reaches an abnormally high temperature to cut off the power supply to the heating element.

[0005]

However, in such a heating device for a water tank, since the heating element is usually buried in the insulating sand, the heat of the heating element is far away through the insulating sand. It takes some time to reach the temperature, and as a result, when the temperature of the thermal fuse rises to the set temperature, the heating element rises to a temperature considerably higher than the set temperature, and the temperature rise of the heating device can be sufficiently increased. There is a problem that it cannot be suppressed.

[0006] The present invention provides a water tank heating apparatus which can quickly suppress the rise in temperature by energizing the main heating element at an early stage when the heating apparatus in which the thermal protector is out of order is energized in the air. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an elongate case in which an enclosed storage space is formed, and a water tank which is housed in one side of the storage space and generates heat when energized. A main heating element for heating water in the inside, a power plug connected to a commercial power supply is provided at one end, and a connection cord whose other end is inserted into the storage space through the other end of the case; A bimetallic thermal protector that is housed in the other side of the space, interposed between one end of the main heating element and the other end of the connection cord, and is turned on and off when the operating temperature is reached by energization in the air; A temperature fuse that is housed in the other side of the housing space, is connected in series with the thermal protector, and melts to cut off the current when the set temperature is higher than the operating temperature of the thermal protector. It is stored in the other side of the storage space in a state pressed against the inner surface of the case, is connected in series to the main heating element, and generates heat together with the main heating element when energized to apply heat to the thermal fuse. This can be achieved by providing a heating element.

Now, the case is submerged in, for example, a water tank for breeding ornamental fish, and a power plug is connected to a commercial power supply, and the main heating element generates heat when energized to heat the water in the water tank. Suppose you have At this time, the sub-heating element also generates heat when energized, but the heat from this sub-heating element is absorbed by the water in the water tank through the case because the sub-heating element is pressed against the inner surface of the case. Alternatively, the thermal fuse is not turned off or blown. Here, if such a heating device is accidentally taken out of the water tank for cleaning the water tank while energizing the main heating element and the like, the case is surrounded by air that performs an insulating function. In addition, the heat from the sub-heating element has no escape area and raises the temperature of the case. Then, when the thermal protector is heated to the shut-off operating temperature by this heat, the thermal protector is turned off,
Cut off the power supply to the main and sub heating elements. At this time, since the fusing temperature of the thermal fuse is a set temperature higher than the operating temperature of the thermal protector, the thermal fuse does not blow before the thermal protector is turned off. Thereafter, when the temperatures of the case and the thermal protector decrease to the return operation temperature, the thermal protector is turned on again, and the power supply to the main and sub heating elements is resumed.
When the thermal protector is repeatedly turned on and off in this manner, the contacts of the thermal protector may be welded and a malfunction may occur while the thermal protector remains on. When the heating device is energized in the air in such a state, heat from the main and sub-heating elements is trapped in the case because there is no escape place, as described above. The heat from the sub-heating element is immediately applied to the thermal fuse to heat the thermal fuse. As a result, the thermal fuse is quickly heated to the set temperature and blown, whereby the power supply to the main heating element is cut off at an early stage, and the temperature rise of the apparatus is reliably suppressed.

According to the second aspect of the present invention, most of the heat from the sub-heating element to the thermal protector and the thermal fuse flows through the case, so that the thermal SN ratio (signal to noise ratio) is increased. ) Is improved. further,
According to the third aspect, the ratio of heat flowing through the case is increased, and the SN ratio is improved. Further, according to the structure described in claim 4, the amount of heat generated from the sub-heating element can be easily and easily adjusted. Further, according to the fifth aspect, since the surface temperature of the sub-heating element is reduced, the temperature gradient between the sub-heating element and the thermal fuse is reduced, and the SN ratio is improved. In addition, according to the configuration of the sixth aspect, it is easy to manage the operating temperature difference between the thermal protector and the thermal fuse, so that the thermal fuse is blown before the thermal protector is turned off. The situation can be prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 11 denotes a heating device for heating the temperature of water in an aquarium for rearing ornamental fish and the like. The heating device 11 has a heater unit 12 submerged in the water in the aquarium. The heater unit 12 has an elongated cylindrical ceramic tube 13 having both ends opened, and the ceramic tube 13 has a rubber cap 1 fitted to both ends thereof.
Sealed by 4 and 15. Ceramic tube 1 mentioned above
3. The rubber caps 14 and 15 as a whole constitute an elongated case 17 in which a storage space 16 hermetically sealed is formed. Partition plates at both ends inside the ceramic tube 13
The ceramic tubes 13 between the partition plates 18, 19 and the rubber caps 14, 15 are filled with sealing materials 20, 21 made of silicon, respectively.

In the ceramic tube 13, the ceramic tube
A partition 23 extending in the axial direction of the partition 13 is provided, and one end and the other end of the partition 23 are connected to the partition plates 18 and 19. Further, a partition wall 24 attached to a partition wall 23 is provided at a central portion in the axial direction of the ceramic tube 13, and the partition wall 24 divides the storage space 16 into one side space located on one side of the case 17.
16a and another space 16b located on the other side of the case 17. Reference numeral 25 denotes a heating element composed of a heating wire wound in a coil shape. The heating element 25 is housed in the housing space 16, and the middle thereof penetrates the partition wall 24. The heating element 25 is divided into a main heating element 26 located in the one-side space 16a and a sub-heating element 27 located in the other-side space 16b. 27 is connected in series. If the main and sub-heating elements 26 and 27 are formed of continuous coil-shaped heating wires as described above, the manufacturing cost can be reduced as compared with a case where these are separately provided and both are connected by a joint. In addition, the axial length of the case 17 can be reduced by the amount of the joint. Here, the main heating element 26 extends along the partition wall 23 and is folded at one end of the partition wall 23.
As a result, the main heating element 26
Releases a large amount of heat from the sub-heating element 27 to heat the water in the water tank. The one side space 16a around the main heating element 26 is filled with insulating sand 28. The insulating sand 28 is
The heat released from 26 is transmitted to the water in the water tank through ceramic tube 13, thereby lowering the surface temperature of main heating element 26 and extending its life. 30 is two core wires 30
The connection cord 30 includes a power plug 31 connected to a commercial power supply at one end. The other end of the connection cord 30 penetrates the rubber cap 15 located at the other end of the case 17, and is inserted into the storage space 16, specifically, the other space 16b.

Reference numeral 34 denotes the other side of the storage space 16, that is, the other side space 16.
The thermal protector 34 is disposed between the other end of the connection cord 30, more specifically, between the other end of one core wire 30 a and one end of the main heating element 26. Reference numeral 35 denotes a thermal fuse housed in the other side of the housing space 16, that is, the other side space 16b. This thermal fuse 35 is connected to the other end of the connection cord 30, specifically, the other end of one core wire 30a and the main heating element 26. , And here, the thermal protector 34. As a result, the thermal protector 34 and the thermal fuse 35 are connected in series, and when one of them is turned off, the power supply to the heating element 25 is cut off.
Reference numeral 36 denotes a sheet-like heat insulator interposed between the thermal protector 34, the temperature fuse 35, and the sub-heating element 27, here, the partition wall 23, and the heat insulator 36 is thermally separated from the sub-heating element 27. Space on the other side to protector 34 and thermal fuse 35
16b (specifically, the air inside) is suppressed. Also, this heat insulator 36 is a thermal protector 34,
The thermal fuse 35 is pressed against the case 17, specifically the inner surface of the ceramic tube 13, and the temperatures of the thermal protector 34 and the thermal fuse 35 are made as close as possible to the temperature of the ceramic tube 13 (water temperature when the heater unit 12 is in water). 37 is the thermal protector 34 and thermal fuse
The heat conductive plate 37 is interposed between the thermal protector 34, the thermal fuse 35 and the ceramic tube 13. The heat guide plate 37 thermally manages the thermal protector 34 and the thermal fuse 35 so that the two always have substantially the same temperature, thereby facilitating the management of the operating temperature difference between the two. Here, when the temperature of the thermal protector 34 rises to the shut-off operation temperature due to air energization to the heating element 25, the thermal protector 34 is turned off to interrupt the energization to the heating element 25, while the temperature is reduced to the return operation temperature. When the temperature drops, the power is turned on, and the power supply to the heating element 25 is restored. When the temperature fuse 35 itself rises to a set temperature higher than the operating temperature due to aerial application to the heating element 25, the thermal fuse 35 melts and cuts off the supply of electricity to the heating element 25.

Reference numeral 41 denotes a metal heat diffusion plate interposed between the inner surface of the other side of the case 17 (ceramic tube 13) and the sub-heating element 27. And extends almost half way toward the thermal fuse 35 and is in close contact with the inner surface of the ceramic tube 13. As a result, the heat released from the sub-heating element 27 is rapidly diffused into the ceramic tube 13 through the heat diffusion plate 41, and lowers the surface temperature of the sub-heating element 27. Also, a thin insulating layer 42 for preventing a short circuit between the sub-heating element 27 and the heat diffusion plate 41 is interposed between the heat diffusion plate 41 and the sub-heating element 27. Here, the sub-heating element
27 is pressed against the case 17, more specifically, the inner surface of the ceramic tube 13, via the insulating layer 42 and the heat diffusion plate 41, and as a result, heat released from the sub-heating element 27 is After being guided to the ceramic tube 13 through 41, the thermal protector 34 and the thermal fuse 35 can be heated. The auxiliary heating element 27 is provided with the thermal protector.
34, it is arranged at a position which is substantially half a circumference in the circumferential direction from the thermal fuse 35, and as a result, the other side space 16b from the sub-heating element 27 to the thermal protector 34 and the thermal fuse 35
Is restricted by the air in the other space 16b, and the ratio of the heat flow through the case 17 (the ceramic tube 13) is increased. Further, the sub-heating element 27 generates heat together with the main heating element 26 at the time of energization, and the amount of heat generated at this time is determined by appropriately adjusting the number of turns of the heating wire located in the other side space 16b, that is, the resistance value during manufacturing. Simple and easy to adjust.

Next, the operation of the embodiment of the present invention will be described. Now, for example, the heater unit 12 is submerged in the water of an aquarium for rearing ornamental fish, and a power plug 31
Is connected to a commercial power supply, the main heating element 26 generates heat by energization, and the water in the water tank is heated. At this time, the sub-heating element 27 also generates heat when energized, but the heat from the sub-heating element 27 is transmitted through the case 17 to the water tank because the sub-heating element 27 is pressed against the inner surface of the case 17 (ceramic tube 13). Absorbed in water. As a result, when the heater unit 12 is submerged in water, the thermal protector 34 or the thermal fuse 35 is not turned off or blown.

Here, the heater unit 12 as described above is used.
When the main and sub-heating elements 26 and 27 are energized and accidentally removed from the water tank to the air, for example, for cleaning the water tank,
Since the surroundings of the case 17 change from water that absorbs heat to air that performs heat insulation, the heat from the main and sub-heating elements 26 and 27 has no escape area and stays in the case 17 to increase the temperature of the case 17. . At this time, since the sub-heating element 27 and the thermal protector 34 are both pressed against the ceramic tube 13 of the case 17, the heat released from the sub-heating element 27 is applied to the thermal protector 34 through the ceramic tube 13. Then, when the temperature of the thermal protector 34 rises to the shut-off operation temperature, the thermal protector 34 is turned off, the power supply to the main and sub-heating elements 26 and 27 is cut off, and the temperature rise of the heater unit 12 is prevented. . At this time, the thermal protector 34 and the thermal fuse 35 are thermally connected to each other by the heat conducting plate 37 in contact with both the thermal protector 34 and the thermal fuse 35, so that the thermal protector 34 and the thermal fuse 35 are almost always at the same temperature. Since the temperature is a set temperature higher than the shut-off operation temperature of the thermal protector 34, the thermal fuse 35 does not blow before the thermal protector 34 is turned off. Thereafter, when the temperature of the case 17 and the thermal protector 34 decreases to the return operation temperature, the thermal protector 34 is turned on again, and the energization to the main and sub-heating elements 26 and 27 is restarted.

When the thermal protector 34 is repeatedly turned on and off in this manner, the thermal protector 34 may fail with the contacts being welded and kept on. However, in such a state, the heater unit 12 may be in the air. When the power is supplied, the heat from the main and sub-heating elements 26 and 27 does not escape, as described above, and starts to accumulate in the case 17. At this time, the auxiliary heating element 27 and the thermal fuse 35 are
In addition, since the sub-heating element 27 and the thermal fuse 35 are both pressed against the ceramic tube 13 of the case 17, the heat released from the sub-heating element 27
Immediately applied to the thermal fuse 35 to heat the thermal fuse 35. As a result, the temperature fuse 35 is quickly heated to the set temperature by the heat from the sub-heating element 27 and melts, and the power supply to the main heating element 26 is cut off at an early stage to reliably suppress the temperature rise of the heater unit 12. . At this time, as described above, by disposing the sub-heating element 27 in a circumferential direction substantially half a distance from the thermal fuse 35, a long air layer is interposed between the thermal fuse 35 and the sub-heating element 27, and the temperature is reduced. Since the heat insulator 36 that blocks the flow of heat through the air from the sub-heating element 27 to the temperature fuse 35 is arranged between the fuse 35 and the sub-heating element 27, the sub-heating element 27 The ratio of the flowing heat flowing through the case 17 (ceramic tube 13) is increased, the thermal SN ratio (signal-to-noise ratio) is improved, and the fusing operation of the thermal fuse 35 becomes accurate. At this time, a heat diffusion plate is provided between the inner surface of the case 17 and the sub-heating element 27.
Since the 41 is interposed, the heat released from the sub-heating element 27 is rapidly diffused into the ceramic tube 13 through the heat diffusion plate 41, and the surface temperature of the sub-heating element 27 is reduced. This allows
The flow of heat through the air from the sub-heating element 27 to the thermal fuse 35 is further reduced, and the SN ratio is further improved.

In the above-described embodiment, the sub-heating element 27 and the main heating element 26 are formed of a continuous coil-shaped heating wire. However, in the present invention, the sub-heating element is provided outside the mica cylindrical body. It may be composed of a heating wire wound spirally. In this case, the thermal fuse may be disposed while being pressed against the inner peripheral surface of the cylindrical body. In the present invention, the sub-heating element may be formed of a stainless steel foil stuck on one side of a polyimide resin sheet or a stainless steel foil sandwiched from both sides by a polyimide resin sheet. Further, in the above embodiment, the storage space
The partition 16 is partitioned into one side and the other side spaces 16a and 16b by a partition wall 24, and only the one side space 16a is filled with insulating sand. In the present invention, the partition wall 24 is removed and the storage space 16a is removed. The whole, that is, one side, the other side space 16a, 16
Both of them may be filled with insulating sand. Also,
In the above-described embodiment, the one-side space 16a is filled with the insulating sand 28. However, in the present invention, such insulating sand may not be filled.

[0018]

As described above, according to the present invention, even if a faulty heating device is energized in the air while the thermal protector remains on, the energization to the main heating element is cut off early. Temperature rise can be reliably suppressed.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II of FIG.

[Explanation of symbols]

 11 ... heating device for water tank 16 ... storage space 16a ... one side space 16b ... other side space 17 ... case 24 ... partition wall 26 ... main heating element 27 ... sub heating element 30 ... connection cord 31 ... power plug 34 ... thermal protector 35 ... Temperature fuse 36 ... Heat insulator 37 ... Heat conductive plate 41 ... Heat diffusion plate 42 ... Insulation layer

Claims (6)

[Claims] An elongated case having a storage space hermetically sealed therein, and a main heating element housed in one side of the storage space and generating heat when energized to heat water in a water tank. A power supply plug connected to a commercial power supply is provided at one end, and the other end is connected to a connection cord inserted into the storage space through the other end of the case, and stored at the other side of the storage space. A bimetallic thermal protector that is interposed between one end of the main heating element and the other end of the connection cord and that is turned on and off when the operating temperature is reached by air conduction, and is housed in the other side of the housing space. A temperature fuse that is connected in series with the thermal protector and cuts off current when a set temperature higher than the operating temperature of the thermal protector is reached, and a case inner surface on the other side of the storage space. And a sub-heating element that is housed in a pressed state, is connected in series to the main heating element, and generates heat together with the main heating element when energized to apply heat to the thermal fuse. Heating device for aquarium. 2. The aquarium tank according to claim 1, wherein the thermal fuse and the thermal protector are disposed in a state of being pressed against the inner surface of the other end of the case, and the sub-heating element is disposed at a distance of approximately half a circumference from the thermal fuse. Heating equipment. 3. A heating device for a water tank according to claim 1, further comprising a heat insulator interposed between said temperature fuse and said sub-heating element to block a flow of heat from said sub-heating element through a storage space to said temperature fuse. 4. A partition wall for partitioning a storage space into one side space and another side space at a boundary between the main heating element and the sub-heating element, and the main and sub-heating elements are separated from a coil-shaped heating wire. The heating device for an aquarium according to claim 1, wherein the heating device is configured to further adjust the number of turns of the heating wire located in the other space to thereby adjust the amount of heat generated from the sub-heating element. 5. A metal heat diffusion plate is interposed between the inner surface of the other side of the case and the sub-heating element, and a thin insulating layer is interposed between the heat diffusion plate and the sub-heating element. The heating device for an aquarium according to claim 1. 6. The thermal protector according to claim 1, further comprising: a metal heat conducting plate in contact with both the thermal protector and the thermal fuse, wherein the thermal protector and the thermal fuse are thermally coupled.
The heating device for an aquarium according to the above.