JPH10284230A - Freezing preventing heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of damage even if surrounding low heat resistant parts touch a freezing preventing heater by holding a surface temperature low when the freezing preventing heater is heated. SOLUTION: A heater cover 12 covering the upper portion and the side portion of a heater element 10 is fitted to a fitting bracket 11. The cover 12 is provided with locking holes 13 on both side face portions, and the fitting bracket 11 has stoppers 14 supporting the lower edge of the cover 12 and a cut-up pawls 15 inserted into the holes 13 of the cover 12. The cover 12 is fixed to the fitting bracket 11 by the stoppers 14, the cut-up pawls 15 and the holes 13. A heating element is contained in a ceramic case 1, the cement agent- filled heater element 10 is placed on a water supply pipe 4, and the cover 12-fitted fitting bracket 11 is covered from above the element 10 so as to fix the element 10 to the pipe 4 utilizing the spring property of both leg portions 11a, 11b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater for preventing freezing of a water supply pipe of, for example, a water heater.

[0002]

2. Description of the Related Art Conventionally, this kind of anti-freezing heater is configured as shown in FIG. Reference numeral 1 denotes a ceramic case, in which a heating element (resistor) (not shown) is housed in a state where lead wires 2 are drawn out from both ends thereof, and is filled with a cement agent 3 for protecting the heating element from above. .
The ceramic case 1 has a concave groove 1a at the bottom. When the ceramic case 1 is mounted on the water supply pipe, as shown in FIG. A mounting bracket 5 made of, for example, stainless steel is placed from the opposite side, and the ends of the legs are pressed against the water supply pipe 4 and fixed using the spring property. The protrusion 1b provided on the side surface of the ceramic case 1 is for preventing the mounting bracket 5 from shifting.

When a heater for freezing prevention is applied to a water heater, three to five heaters are connected in series or in parallel, and are mounted separately at required locations in a water supply pipe.

[0004]

However, in the above-mentioned conventional construction, when the heater is heated to prevent freezing of water in the water supply pipe, the surface temperature of the heater element rises to over 200 ° C. at the highest point. Therefore, there is a problem that a low heat-resistant component such as a harness disposed near the heater element contacts the heater element and burns the coating of the harness.

The present invention has been made in order to solve the above-mentioned problems of the prior art.
An object of the present invention is to provide a heater for preventing freezing, which does not cause damage.

[0006]

In order to achieve the above object, a heater for freezing prevention according to the present invention comprises a ceramic case having a concave groove on a bottom surface, in which a heating element from which a lead wire is drawn is housed, and a cement agent is provided. And the concave groove of the ceramic case is brought into contact with a water supply pipe for preventing freezing, and is covered from the surface opposite to the concave groove of the ceramic case. A mounting bracket for fixing the heater element to the water supply pipe by pressing the tip against the water supply pipe, and a heat-resistant heater cover covering the upper and side parts of the heater element from above the mounting bracket. The heater cover has locking holes on both side surfaces thereof, and the mounting bracket is inserted into a locking hole of the heater cover and a stopper for supporting a lower edge of the heater cover. Ri cause has a pawl, the stopper, the cut-and-raised claws and engagement holes, in which a structure for securing the heater cover to the mounting bracket. When the heater cover is fixed to the mounting bracket, a gap is formed between the inner surface of the heater cover and the mounting bracket and the heater element.

[0007] According to the above configuration, the heat dissipation from the heater element and the mounting bracket is suppressed to improve the heat efficiency of the water supply pipe heating, and the surface temperature of the heater cover can be reduced to 100 ° C or less. Even if the low heat-resistant parts come in contact with each other, they will not be damaged.

[0008] The heater cover has an extended portion at a part of a lower edge portion on both sides to cover an outer surface of at least a part of a leg portion of the mounting bracket when the heater cover is fixed to the mounting bracket. When a gap is formed between the inner surface of the extended portion of the heater cover and the leg of the mounting bracket, heat radiation from the leg of the mounting bracket is suppressed, and the protection range of the low heat-resistant component is extended. .

Further, the heater element has at least one locking projection, the mounting bracket has a second cut-and-raised claw that engages with the locking projection, and the mounting bracket covers the heater element. At this time, the second cut-and-raised claw is engaged with the locking projection so that the heater element can be temporarily fixed to the mounting bracket. In this way, the heater can be easily attached and fixed to the water supply pipe simply by temporarily fixing the heater element and fitting the mounting bracket with the heater cover attached to the water supply pipe. Will be better.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 shows a heater for preventing freezing in Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view thereof. 1 and 2, reference numeral 10 denotes a heater element, which is the same as the conventional example. That is,
Reference numeral 1 denotes a ceramic case having a concave groove 1a on the bottom surface, and accommodates a heating element (resistor) (not shown) from which a lead wire 2 is drawn out. Reference numeral 3 denotes a cement filled to protect the heating element.

Reference numeral 11 denotes a concave groove 1a of the ceramic case 1,
Abuts the water supply pipe 4 to prevent freezing, and the ceramic case 1
The mounting bracket 11 is fitted from the surface opposite to the concave groove 1a. The fitted mounting bracket 11 presses the distal ends of both legs 11a and 11b having spring properties to the water supply pipe 4 to press the heater element.
10 is fixed to the water supply pipe 4. Reference numeral 12 denotes a heat-resistant heater cover which covers the upper and side portions of the heater element 10 from above the mounting bracket 11. As the heater cover 12,
For example, mica products are used.

The heater cover 12 has locking holes 13 on both sides.
The mounting bracket 11 has a stopper 14 that supports the lower edge 12a of the heater cover 12, and a cut-and-raised claw 15 that is inserted into the locking hole 13 of the heater cover.

The attachment of the freeze prevention heater to the water supply pipe 4
First, a heater cover 12 covering the upper and side portions of the heater element 10 is put on the mounting bracket 11.
At this time, the lower edges 12a of both sides of the heater cover 12 hit the stoppers 14 of the mounting bracket 11, the cut-and-raised claws 15 of the mounting bracket 11 are inserted into the locking holes 13 of the heater cover 12, and the heater cover 12 is mounted. It is fixed to the bracket 11.
In the fixed state, a gap G is formed between the inner surface of the heater cover 12 and the mounting bracket 11.

Next, a mounting bracket 11 on which a heater cover 12 is previously mounted is placed over the heater element 10 in which the concave groove 1a of the ceramic case 1 is in contact with the water supply pipe 4, and both leg portions 11a of the mounting bracket 11 are provided. , 11b are pressed against the lower surface on the side of the water supply pipe 4, and the heater element 10 is fixed to the water supply pipe 4 by utilizing its spring property. In this case, the heater element 10 may be fitted in the mounting bracket 11 in advance, and the mounting bracket 11 may be put on the water supply pipe 4.

According to the first embodiment configured as described above, when the heater cover 12 made of mica having a thickness of 1 mm is covered and the gap G is about 2 mm, the surface temperature of the heater element 10 becomes about 300 mm.
℃, the surface temperature of the heater cover 12 is about 90 ℃, about 210
A temperature decrease of ° C was confirmed.

(Embodiment 2) FIG. 4 shows a heater for preventing freezing according to Embodiment 2 of the present invention. here,
When the heater cover 12 is fixed to the mounting bracket 11 at a part of the lower edge of both sides of the heater cover 12, the mounting bracket
An extension 12b is provided to cover at least a part of the outer surface of the 11 legs 11a and 11b. In this way, the heat radiation from the legs 11a and 11b of the mounting bracket 11 is also suppressed, and the protection range of the low heat resistant component is expanded.

Further, in this case, as shown in FIG. 5, if a gap g is formed between the inner surface of the extended portion 12b of the heater cover and the legs 11a and 11b of the mounting bracket 11,
Heat radiation from the legs 11a and 11b of the mounting bracket 11 can be more effectively suppressed, and the surface temperature of the extension 12b can be reduced.

(Embodiment 3) FIG. 6 shows a heater for preventing freezing according to Embodiment 3 of the present invention. Here, at least one locking projection 16 is provided on the heater element 10.
The mounting bracket 11 is provided with a second cut-and-raised claw 17 (15 is a first cut-and-raised claw) that engages with the locking projection 16, and the mounting bracket 11 is placed over the heater element 10. The second cut-and-raised claw 17 is engaged with the locking projection 16 so that the heater element 10 can be temporarily fixed to the mounting bracket 11. With such a configuration, the heater for preventing freezing is easily attached and fixed to the water supply pipe simply by temporarily fixing the heater element 10 and fitting the mounting bracket 11 with the heater cover 12 attached to the water supply pipe 4. And the mounting workability is greatly improved.

[0019]

As described above, according to the present invention,
By covering the upper surface and both side surfaces except the contact surface of the heater element with the water supply pipe and the lead wire drawing surface with the heater cover, heat radiation from the three surfaces is suppressed, so that the heat efficiency of heating the water supply pipe is remarkably improved. Also, by forming a gap between the inner surface of the heater cover and the mounting bracket and the heater element, the surface temperature of the heater cover can be reduced to 100 ° C.
It is lowered below, and even if the surrounding low heat-resistant parts come into contact, no damage is caused. Furthermore, if the heater element is temporarily fixed to the mounting bracket in advance, the mounting workability is improved, and effects such as cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view (a) and a side view showing a state in which a freeze prevention heater according to Embodiment 1 of the present invention is attached to a water supply pipe.
(b).

FIG. 2 is an exploded perspective view of the anti-freezing heater according to Embodiment 1 of the present invention.

FIG. 3 is a perspective view (a) of a conventional anti-freezing heater and a side view (b) attached to a water supply pipe.

FIG. 4 is a perspective view (a) and a side view showing a state in which a freeze prevention heater according to Embodiment 2 of the present invention is attached to a water supply pipe.
(b).

FIG. 5 is a diagram showing a modification of the second embodiment of the present invention.

FIG. 6 is a perspective view showing a structure for temporarily fixing a heater element to a mounting bracket according to a third embodiment of the present invention.

[Explanation of symbols]

4 ... water supply pipe, 10 ... heater element, 11 ... mounting bracket, 12 ... heater cover, 13 ... locking hole, 14 ... stopper, 15 ... cut-and-raised claw (first), 16 ... locking projection,
17 ... Second cut and raised claw.

Claims (5)

[Claims] 1. A heater element in which a heating element from which a lead wire is drawn is housed in a ceramic case having a concave groove on the bottom surface, and a cement element is filled, and the concave groove of the ceramic case is prevented from freezing. A mounting bracket which abuts on the water supply pipe, covers from the surface of the ceramic case opposite to the concave groove, presses the ends of the two legs having spring properties to the water supply pipe, and fixes the heater element to the water supply pipe; A heat-resistant heater cover covering the upper and side portions of the heater element from above the mounting bracket, wherein the heater cover has locking holes on both side surfaces, and the mounting bracket Has a stopper for supporting a lower edge of the heater cover, and a cut-and-raised claw inserted into a locking hole of the heater cover. A heater for freezing prevention, wherein the heater cover is fixed to the mounting bracket. 2. The freezing prevention heater according to claim 1, wherein when the heater cover is fixed to the mounting bracket, a gap is formed between the inner surface of the heater cover and the mounting bracket and the heater element. 3. The heater cover has, at a part of a lower edge portion on both sides thereof, an extension portion that covers an outer surface of at least a part of a leg portion of the mounting bracket when the heater cover is fixed to the mounting bracket. The heater for preventing freezing according to claim 1. 4. The heater according to claim 3, wherein a gap is formed between the inner surface of the extending portion of the heater cover and the leg of the mounting bracket. 5. The heater element has at least one locking projection, the mounting bracket has a second cut-and-raised claw that engages with the locking projection, and the mounting bracket is attached to the heater element. 2. The freezing prevention heater according to claim 1, wherein the second cut-and-raised claw is engaged with the locking projection to temporarily fix the heater element to the mounting bracket when the cover is put on.