JPH0729804U - Fixed resistor element body and fixed resistor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fixed resistor which can improve productivity and also can reduce the price of a lead wire. [Structure] A rod-shaped resistor 10 and a ceramic case 30 are provided. The metal wires 13, 13 are attached to both ends of the resistor 10, and the ceramic case 30 has a first housing portion 31 for housing the resistor 10 and second and third housings located on both sides of the first housing portion 31. Storage parts 35 and 37 are provided. Resistor 10
Is housed in the first housing portion 31, and the ends of the metal wires 13, 13 at both ends of the resistor 10 are moved from the first housing portion 31 to the second housing portion 2.
The first accommodating portion 31 is sealed with an insulating material in a state of being projected into the third accommodating portions 35 and 37. Metal wire 1
Lead wires 60, 60 are connected to the tips of 3, 13, and the connection portions are housed in the second and third housing portions 35, 37 and sealed with an insulating material to form the fixed resistor 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fixed resistor element body and a fixed resistor used for an antifreezing heater of a water heater.

[0002]

[Prior art]

 Conventionally, fixed resistors have been used as antifreeze heaters that heat the water pipes of water heaters installed outdoors. That is, a fixed resistor is attached to each of a plurality of predetermined locations of the water supply pipe of the water heater, and when the outside air temperature or the temperature of the water supply pipe falls below a predetermined value, an electric current is passed through the fixed resistor to generate heat. This prevents freezing of water in the pipe.

FIG. 7 is a side sectional view showing a conventional fixed resistor of this type. To manufacture this fixed resistor 100 as shown in the figure, first, both ends of a cylindrical resistance element 101 are covered with metal caps 103, 103, and lead wires 105, 105 are provided in the metal caps 103, 103. The core wires 105a and 105a are inserted, and the outer peripheral side surfaces of the metal caps 103 and 103 are caulked to integrate them.

Next, the resistance element 101 is housed in a ceramic case 107 having an open upper surface, and a heat-resistant silicon cement 109 is filled and sealed around the ceramic case 107. Next, waterproof silicone rubber 111 is applied to both end surfaces of the ceramic case 107. Then, after being dried naturally, it is sintered (for example, 90 minutes at 180 ° C.).

FIG. 8 is a diagram showing a state in which a plurality of fixed resistors 100 are connected by a lead wire 105 to be actually attached to a water passage pipe of a water heater. As shown in the figure, in the fixed resistor 100, the lengths L1, L2, L3, ... Of the lead wires 105 are changed according to the position of the water pipe to be attached.

As described above, the fixed resistors 100 used as the antifreezing heater are usually connected in series by the lead wire 105 (1 to 14 stations).

Since the water heater has different specifications and structure of the water passage pipe for each model of each manufacturer, not only the number of fixed resistors 100 to be attached differs for each model, but also the length and color of the lead wire 105. Also varies from model to model, and the resistance value of the fixed resistor 100 also varies from model to model. In other words, different types of water heaters of different manufacturers must be manufactured with different structures.

[0008]

[Problems to be solved by the device]

 However, the above conventional example has the following problems. Since the length of the lead wire 105 to be connected as described above varies depending on the order of the water heater manufacturer, it is not possible to manufacture the fixed resistor 100 to which the lead wire 105 is connected in advance. The resistance element 101 and the lead wire 105 having a required length must be prepared and manufactured.

In particular, in the case of the fixed resistor 100 having the above structure, the lead wire 105 is directly attached to the resistance element 101, and the resistance element 101 to which the lead wire 105 is attached is housed in the ceramic case 107. Due to its structure, the lead wire 105 is also simultaneously embedded in the heat resistant silicon cement 109 in which the resistance element 101 is embedded.

Therefore, in order to manufacture the fixed resistor 100 to order, it is necessary to always start the connection of the lead wire 105 with the resistance element 101. In other words, it is not possible to pre-manufacture intermediate processes and stock them, but all manufacturing processes must be performed from the time of ordering to the delivery date. For this reason, planned production cannot be performed and productivity cannot be improved.

The resistance element 101 of the fixed resistor 100 is energized and heated. However, for example, when the fixed resistor 100 comes off from the water pipe and is in a so-called air-fired state, the temperature is considerably high. Become.

On the other hand, since the lead wires 105, 105 are directly connected to the metal caps 103, 103 of the resistance element 101, their coatings are located close to the resistance element 101, and the fixed resistor 100 is If it is air-baked, this coating will also be quite hot. Therefore, the coating of the lead wires 105, 105 must be able to withstand high temperatures, and for this reason, for example, a silicon rubber glass braided electric wire was specifically used.

However, this silicon rubber glass braided electric wire is expensive, which hinders the price reduction of the fixed resistor 100.

The present invention has been made in view of the above points, and an object thereof is to provide a fixed resistor element body and a fixed resistor which can improve productivity and also can reduce the cost of a lead wire. There is something to do.

[0015]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention comprises a resistor having metal wires attached to both ends thereof and a ceramic case, and the ceramic case includes a first housing part for housing the resistor and the first housing. Second and third accommodating portions located on both sides of the resistor are provided, the resistor is accommodated in the first accommodating portion of the ceramic case, and the metal wires at both ends of the resistor are moved from the first accommodating portion to the first accommodating portion. Second, the fixed resistor element body was formed by filling the first accommodating portion with an insulating material and sealing the resistor in a state of being projected into the third accommodating portion.

In the present invention, lead wires are connected to the ends of both metal wires of the fixed resistor element body, the connection parts are housed in the second and third housing parts and sealed with an insulating material. A fixed resistor was constructed.

[0017]

Due to its structure, this fixed resistor has a step of accommodating a resistor in the first accommodating portion and sealing it with an insulating material, and connecting a lead wire to the resistor to connect the connecting portion. Can be manufactured in a completely different step from the step of sealing with an insulating material. For this reason, fixed resistor elements can be manufactured and stocked in advance, and when an order is received, all that is required is to connect the lead wire and seal it. Can be shortened.

Further, in this fixed resistor, the distance between the connection portion and the resistor is considerably large because the metal wire is interposed. For this reason, the heat generated by the resistor is difficult to be transferred to the lead wire, so that a fairly inexpensive lead wire can be used.

[0019]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic exploded perspective view of a fixed resistor according to the present invention. As shown in the figure, in this fixed resistor 1, the resistor 10 is housed in the first housing portion 31 of the ceramic case 30 and filled with an insulating material (not shown), and then both ends of the resistor 10 are filled. The lead wires 60 and 60 are connected to the metal wires 13 and 13 attached to the metal bands 70 and 70 by the metal bands 70 and 70, and the connecting portions are housed in the second and third housing portions 35 and 37, and an insulating material (not shown) is provided. ). Each component will be described below.

The resistor 10 is formed by winding a resistance wire around the outer periphery of a cylindrical insulator, covering both ends thereof with metal caps 11, 11, and caulking the outer peripheral side face of the resistor wire. The metal wires 13, 13 are previously connected to the outer end surfaces of the metal caps 11, 11 by welding.

FIG. 2 is a side sectional view of the ceramic case 30. As shown in FIGS. 1 and 2, the ceramic case 30 is formed in a substantially rectangular parallelepiped shape, and a first housing portion 31 having a size for housing the resistor 10 is provided in the center thereof. Second and third storage portions 35, 37 are provided on both sides of the storage portion 31 via partition walls 33, 33.

The partitions 33, 33 are provided with grooves 39, 39 for inserting the metal wires 13, 13 of the resistor 10, and also on both sides of the second and third storage parts 35, 37. Grooves 41, 41 for inserting the lead wires 60, 60 are provided. As shown in FIG. 2, inclined surfaces 40, 40 are provided in the grooves 39, 39 so that their lower surfaces open upward.

Further, as shown in FIG. 1, a guide groove 43 for a metal fitting (not shown) for fixing the ceramic case 30 to the water pipe is provided on the side surface of the ceramic case 30. Further, a V groove 45 serving as a water pipe mounting surface is provided on the lower surface.

Next, a method for manufacturing the fixed resistor 1 will be described. The manufacturing process of the fixed resistor 1 can be divided into a first process until the fixed resistor element body 50 is manufactured and a second process until the final product of the fixed resistor 1 is manufactured.

[First Step] As shown in FIG. 2, first, the resistor 10 is housed in the first housing portion 31 of the ceramic case 30. The metal wires 13, 13 reach the second and third storage parts 35, 37 via the grooves 39, 39. At this time, even if the metal wires 13 and 13 are initially straight in the longitudinal direction of the resistor 10, they will contact the inclined surfaces 40 and 40 when the resistor 10 is stored in the first storage portion 31. , Is deformed according to the inclined surfaces 40, 40 and bends upward. Note that it may be bent upward from the beginning.

Next, as shown in FIG. 3, an insulating material 47 made of heat-resistant silicon cement or the like is filled and sealed only in the first storage portion 31 of the ceramic case 30. Then, it is naturally dried and then sintered (for example, 180 ° C. for 90 minutes).

As a result, the fixed resistor element body 50 is manufactured. The fixed resistor element body 50 is in a state in which the lead wires 60, 60 are not attached, and therefore, the fixed resistor element elements of the number and the kind which will be necessary in advance for each resistor element 10 having a different resistance value. The body 50 can be manufactured and stocked.

Since the fixed resistor element body 50 is manufactured in a state where the lead wires 60, 60 are not attached to the resistor body 10, the work is easy and the productivity is improved.

[Second Step] Next, when a fixed resistor is ordered from the manufacturer, the lead wires 60, 60 are cut to a required length and the stocked fixed resistor element body 50 is required. After taking out the amount, the core wires of the lead wires 60, 60 are fixed to the tips of the metal wires 13, 13 shown in FIG. 3 by using metal bands 70, 70 as shown in FIG.

Then, the connecting portion 55 is housed in the second and third housing portions 35 and 37 shown in FIG. 3, and the lead wires 60 and 60 are inserted into the grooves 41 and 41. 2. An insulating material 47 made of heat-resistant silicon cement or the like is filled and sealed in the third storage portions 35 and 37. Then, if it is naturally dried and then sintered, the fixed resistor 1 as shown in FIG. 5 is completed. FIG. 6 is a side sectional view thereof.

The insulating material 47 filled in the second and third accommodating portions 35, 37 may be the same material as the insulating material 47 filled in the first accommodating portion 31, but the lead wire 60 will be described below. When 60 and 60 are electric wires having not so high heat resistance, a low temperature curing type heat resistant silicone cement having a low temperature during sintering (for example, 90 minutes at a sintering temperature of 50 to 70 ° C.) may be used.

As described above, the fixed resistor 1 has a structure in which the resistor 10 is housed in the first housing portion 31 and is sealed with the insulating material 47. The steps of connecting the wires 60, 60 and sealing the connecting portion 55 with the insulating material 47 can be performed separately. For this reason, the fixed resistor element body 50 can be manufactured and stocked in advance, and when an order is received, only connecting the lead wires 60, 60 and sealing the lead wires 60 and 60 is required. The period of can be shortened.

Further, in the fixed resistor 1, as shown in FIG. 6, the distance between the connecting portions 55, 55 and the resistor 10 is considerably large because the metal wire 13 is interposed. Moreover, partition walls 33, 33 having good heat dissipation are provided between the connecting portions 55, 55 and the resistor 10. Therefore, the heat generated in the resistor 10 is hard to be transferred to the lead wires 60, 60.

According to an air-fired operation test of the fixed resistor, the following results were obtained. That is, the fixed resistor 1 of the present embodiment and the conventional fixed resistor 100 shown in FIG. 7 each having a rating of 7 W were prepared, and an excess power of 16 W was applied to the fixed resistor 1 for air burning. As a result, the temperature of the central portion of the resistance element 101 of the conventional fixed resistor 100 is about 530 ° C., the temperature of the end portion of the coating of the lead wire 105 is about 230 ° C., and the resistance of the fixed resistor 1 of the present embodiment is small. The temperature of the central portion of the body 10 was about 490 ° C, and the temperature of the end portion of the coating of the lead wire 60 was about 160 ° C. That is, the temperature of the end portion of the coating of the lead wire 60 of the fixed resistor 1 of the present embodiment was about 70 ° C. lower than the temperature of the end portion of the coating of the lead wire 105 of the conventional example.

For this reason, as the lead wires 60, 60 of the fixed resistor 1, not the conventional expensive silicone rubber glass braided electric wire, but the cross-linked polyethylene electric wire or the cross-linked vinyl chloride electric wire or the heat-resistant chlorinated wire, which has low heat resistance but is inexpensive You can use vinyl wires.

Further, in the case of this fixed resistor 1, the connecting portions 55, 55 can be reliably sealed and waterproofed by the second and third storage portions 35, 37, so that the waterproof silicone rubber shown in FIG. It becomes unnecessary.

It is needless to say that the fixed resistor element body and the fixed resistor according to the present invention can be used for various purposes other than the antifreezing heater of the water heater.

[0038]

[Effect of device]

 As described in detail above, the fixed resistor element body and the fixed resistor according to the present invention have the following excellent effects. Since the fixed resistor element body can be manufactured and stocked in advance, planned production is also possible, and it is easy to manufacture.When an order is received, only the lead wire connection and its sealing are performed. All that is required is that the time from order receipt to delivery can be shortened, improving overall productivity.

Since the heat generated by the resistor does not easily transfer to the lead wire, an inexpensive electric wire can be used as the lead wire.

[Brief description of drawings]

FIG. 1 is a schematic exploded perspective view of a fixed resistor 1 according to the present invention.

FIG. 2 is a side sectional view of a ceramic case 30.

3 is a perspective view showing a fixed resistor element body 50. FIG.

FIG. 4 is a perspective view of a main portion showing a connecting portion 55 between a metal wire 13 and a lead wire 60.

5 is a perspective view of the fixed resistor 1. FIG.

FIG. 6 is a side sectional view of the fixed resistor 1.

FIG. 7 is a side sectional view showing a conventional fixed resistor.

8 is a diagram showing a state in which a plurality of fixed resistors 100 are connected by lead wires 105. FIG.

[Explanation of symbols]

 1 Fixed Resistor 10 Resistor 13, 13 Metal Wire 30 Ceramic Case 31 First Storage Section 35 Second Storage Section 37 Third Storage Section 47 Insulation Material 50 Fixed Resistor Element Body 60, 60 Lead Wire

Claims (2)

[Scope of utility model registration request] 1. A resistor body having metal wires attached to both ends thereof and a ceramic case, wherein the ceramic case includes a first housing portion for housing the resistor body, and a first housing portion located on both sides of the first housing portion. Second and third accommodating parts are provided, and the resistor is accommodated in the first accommodating part of the ceramic case, and the metal wires at both ends of the resistor are in the second and third accommodating parts from the first accommodating part. With the first part protruding,
2. A fixed resistor element body, wherein the housing is filled with an insulating material to seal the resistor. 2. A lead wire is connected to the tips of both metal wires of the fixed resistor element body according to claim 1, and the connection portions are housed in the second and third housing portions and sealed with an insulating material. A fixed resistor characterized in that.