Electrical heating apparatus, method of manufacturing heat generator unit and pressing jig

Abstract

An electrical heating apparatus has: a fin brazed on at least one of a main body upper wall and a main body lower wall of a tube; an insertion unit having an electro-heat-generating element pressure-welded to a wall of one of the main body upper wall and the main body lower wall; and an edge part projected in the width direction from each of main body vertical walls to form an edge space. The edge space is formed so as to be continuous with the insertion space and is smaller in thickness dimension than the thickness dimension of the insertion unit.

Description

technical field [0001] The present invention relates to an electrothermal device including an energized heating element called a PTC (Positive Temperature Coefficient: Positive Temperature Coefficient) element that generates heat when energized, a method for manufacturing a heating unit, and a pressure jig. Background technique [0002] Conventionally, an electrothermal device in which a PTC element that generates heat when energized and a heat sink that dissipates the heat generated by the PTC element is laminated is known, for example, from Japanese Patent Application Laid-Open No. 5-169967. [0003] As such an electric heating device, the known structure is that the electrode plate and the insulating plate are stacked on the electric heating body in order to form an assembly contained in a conductive tube body, and then the heat sink is crimped or bonded to the tube body. on the outside. [0004] In this kind of electric heating device, the electrode plate and the heat s...

AI Technical Summary

Problems solved by technology

[0005] As in the above-mentioned prior art, when the contact pressure between the electrode plate and the tube body of the energized heating element such as the PTC element is lower than the set pressure, the heat generation and heat dissipation cannot be completed smoothly, and sufficient heat generation cannot be obtained.

In other words, when the contact pressure between the energized heating element and the tube body is low, the heat generated by the energized heating element cannot be smoothly transferred to the tube body. At this time, the temperature of the energized heating element itself becomes high, and the resistance value increases. , energization and heating cannot be completed smoothly

[0006] Therefore, in the case where an urging member such as a spring is provided to ensure the contact pressure between the energized heating element and the pipe body, the number of parts increases, leading to an increase in cost and weight

[0007] On the other hand, in order to ensure the contact pressure between the pipe body and the electric heating element, the pipe body can be stamped, but in this case, in order not to damage or overload the electric heating element housed inside, press processing is difficult

In addition, when the energized heating element is pressurized and the edge portions at both ends of the pipe body are press-worked, the upper wall and the lower wall of the pipe body expand and deform outward, and the desired contact pressure may not be obtained.

[0008] In addition, when performing the stamping process of the tube body, the fins cannot be brazed to the tube body in the previous process of the stamping process, and after the energized heating element is inserted into the tube body, once the heat sink is brazed , the heat during brazing will damage the energized heating element

[0009] Therefore, instead of brazing, the cooling fins are lapped or bonded to the tube body, but compared with the case of brazing, the heat sink and the tube body are lapped or bonded, and the distance from the tube body to the cooling fins is lower. Poor thermal conductivity, resulting in low heat generation performance

[0010] In this way, in the prior art, it is necessary to ensure the heat conduction performance from the tube body to the cooling fin without using a biasing member while ensuring the contact pressure between the tube body and the current heating element, so as to obtain sufficient heat generation performance of the current flow heating element. difficult

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