JPH0545985U - Electric heater - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent brazing filler metal from flowing into the gaps between electric heating elements and to ensure proper assembly to prevent damage. [Structure] A plurality of electric heating elements 3 between a plurality of fins 2
Is an electric heater 1 in which the brazing material is prevented from flowing into a gap A formed between the electric heating elements 3 at both ends in the arrangement direction of the electric heating elements 3. Avoidance means (outflow prevention projections 13 and 14) are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electric heater used in an air conditioner or the like.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, in an air conditioner such as a vehicle air conditioner, it is well known that an electric heater is provided as an auxiliary heater that operates until a heater core reaches a heating state. Further, this type of electric heater is not limited to assisting the above heater core, but is also used as a heater or a heater independent of itself, for example, when the engine is temporarily stopped and during a nap or the like. is there.

Such an electric heater generally uses a PTC (Positive Temperature Coefficient) element made of a semiconductor ceramic having a positive temperature characteristic as an electric heating element, and heats the electric heating element by energizing to transfer the heat to the fins. However, the air passing between the fins is heated (see, for example, JP-A-61-27081 and JP-A-2-53628).

A plurality of the electric heating elements are arranged side by side between the fins, and a predetermined width is provided between the electric heating elements in consideration of expansion due to thermal expansion of the electric heating elements. A gap is provided. Further, the core of the heater constituted by the fins and the electric heating element etc. is generally assembled by brazing.

[0005]

[Problems to be solved by the device]

 However, in the electric heater according to the above prior art, when the tops of the fins come into contact with or come close to the gaps between the electric heating elements, the brazing material clad in the fins or the fins and the electric heating elements are There was a problem that the brazing filler metal inserted in the gap flows into this gap during brazing and fills the gap to regulate the expansion of thermal expansion of the electric heating element. If the gaps between the electric heating elements are filled, there will be no escape during thermal expansion of the electric heating elements, and the electric heating elements will be damaged.

Further, if the fins stacked by the brazing filler metal flowing into the gap are connected, there is a problem that a short circuit occurs if the fins have different polarities.

In view of the above problems, the present invention has been made in view of the above-mentioned problems, in which the brazing material is prevented from flowing into the gaps between the electric heating elements, and proper assembly is performed to prevent damage or the like. An object of the present invention is to provide an electric heater.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, an electric heater according to the present invention is an electric heater having a plurality of fins arranged in parallel between a plurality of fins, and the electric heaters are arranged in an array. The avoiding means for avoiding the flow of the brazing material into the gap formed between the electric heating elements is provided at both ends in the direction.

[0009]

[Action]

 Therefore, the brazing material is prevented from flowing into the gap between the electric heating elements via the avoiding means provided at both ends of the electric heating element, thereby solving the above problem.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of the structure of an electric heating device. The electric heating device 1 includes a plurality of electric heating devices arranged in parallel between a plurality of corrugated fins 2. Basically, the element (PTC element) 3 is arranged, and the electrode plates 4, 5, 6 are arranged at the center and both ends in the stacking direction.

The fin 2 is a corrugated type of a thin plate bent in a wave shape, and is made of a conductive material such as an aluminum alloy. A brazing material for brazing the fin 2 to the electric heating element 3 described below is clad on the surface of the fin 2.

As the electric heating element 3, a well-known PTC element made of, for example, a ceramic semiconductor is used, and a plurality of electric heating elements 3 are arranged in parallel in a layer between a pair of upper and lower fins 2. The electric heating elements 3 are arranged in parallel with each other with a gap A having a predetermined width (for example, about 1 mm) provided between the adjacent electric heating elements 3 in consideration of expansion during heat expansion due to energization. Outflow prevention projections 13 and 14 are vertically formed at both ends of each electric heating element 3 in the arrangement direction so as to prevent the brazing material cladded by the fins 2 from flowing into the gaps A. There is. That is, the outflow-preventing projections 13 and 14 position the tops of the fins 2 in the direction opposite to the gaps A to prevent them from coming into contact with or approaching the gaps A, so that the brazing filler metal that melts from the fins 2 becomes gaps. It is prevented from flowing in the A direction. As will be described later, the electric heating element 3 generates heat when energized, transfers the heat to the fin 2, and heats the air passing through the fin 2.

The electrode plates 4, 5 and 6 are for supplying an electric current to the core of the electric heater 1. For example, the electrode plates 4 and 5 and 6 are made of a conductive material such as a thin aluminum alloy. It is connected to the positive electrode side of the battery 11 via the switch 10, and the electrode plates 5 and 6 are directly connected to the negative electrode side of the battery 11. A brazing material for brazing the electrode plates 4, 5, 6 and the fin 2 is clad on the surfaces of the electrode plates 4, 5, 6.

The electric heater 1 having the above structure is manufactured by integrally brazing the fins 2, the electric heating elements 3, and the electrode plates 4, 5, 6 with a jig and brazing them in a furnace. When the switch 10 is turned on, the manufactured electric heater 1 is energized from the electrode plate 4 to the upper and lower two sets of electric heating elements 3 through the fins 2 to generate heat from the electric heating elements 3. The heat generated by the heat is transmitted to the fins 2 and heats the air passing through the fins 2 to perform a heating function.

However, as described above, the electric heater 1 is provided with the outflow preventing projections 13 and 14 for preventing the flow of the brazing material at both ends of the electric heating elements 3 in the arrangement direction. The brazing filler metal that melts from the fins 2 during attachment is not blocked by the outflow preventing projections 13 and 14 to reach the gap A between the electric heating elements 3, and the gap A is properly secured. As a result, the degree of freedom of expansion of the electric heating element 3 at the time of heat expansion is properly secured, and damage or the like does not occur. Further, by preventing the brazing material from flowing into the gap A, the upper and lower fins 2 that sandwich the electric heating element 3 are not connected, and a short circuit of the power supply is avoided.

By appropriately setting the width of the electric heating element 3 and the shapes of the outflow prevention protrusions 13 and 14 formed therein, the tops of the fins 2 can be locked. Therefore, the pitch of the fins 2 can be easily determined, the air flow resistance is balanced, and the heat exchange rate can be improved.

[0018]

[Effect of the device]

 As described above, according to the present invention, the avoiding means for preventing the flow of the brazing material into the gap formed between the electric heating elements is provided at both ends in the arrangement direction of the electric heating elements. It is properly secured and damage to the electric heating element can be prevented. Also, by preventing the brazing material from flowing into this gap, the upper and lower fins that sandwich the electric heating element are not connected, a short circuit of the power supply is avoided, and proper assembly can be achieved. The effect is that it can be done.

[Brief description of drawings]

FIG. 1 is a perspective view of an electric heater.

FIG. 2 is an enlarged view of a main part of an electric heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric heater 2 Fin 2 3 Electric heating element (PTC element) 4, 5, 6 Electrode plate 10 Switch 11 Battery 13, 14 Outflow prevention protrusion (avoidance means)

Claims (1)

[Scope of utility model registration request] 1. An electric heater comprising a plurality of electric heating elements arranged side by side between a plurality of fins, the electric heating elements being formed between the electric heating elements at both ends in the arrangement direction of the electric heating elements. An electric heater provided with an avoiding means for avoiding the flow of the brazing material into the gap.