JP2018088316A - heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of a heater for a long term.SOLUTION: A heater comprises: a ceramic body 1; a heating resistor 2 provided in a ceramic body 1; a lead terminal 3 connected to the heating resistor 2 provided on a surface of the ceramic body 1; and a caulking metal jig 42 that holds a core wire 41 connected to the lead terminal 3 in a bundle state. The caulking metal jig 42 includes a main part, and a pair of claw parts extended from the main part. The pair of claw parts is caulked and holds a plurality of core wires 41, and the pair of claw parts and the lead terminal 3 are welded.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heater.

  As a heater used in a gas range, an in-vehicle heating device, an oil fan heater, a glow plug of an automobile engine, or the like, a heater in which a heating element is provided inside a ceramic body is known. An example of the heater is a ceramic heater disclosed in Patent Document 1. The heater disclosed in Patent Document 1 includes a ceramic base, a heat generating part embedded in the base, and a power feeding part embedded in the base and connected to the heat generating part.

  Further, as a crimp terminal including a plurality of lead wires, for example, a crimp terminal disclosed in Patent Document 2 is known. The crimp terminal disclosed in Patent Document 2 includes a plurality of core wires and a fixing portion that holds the plurality of core wires in a bundled state. The fixing portion has a pair of side portions, and the side portion is bent toward the core wire to fix the core wire.

JP 2000-156275 A JP 2012-114095 A

  However, for example, when the crimp terminal described in Patent Document 2 is connected to the power feeding portion of the heater described in Patent Document 1, it is difficult to improve the long-term reliability of the crimp terminal. Specifically, when the heater is used, the heat generated in the heat generating portion is transmitted to the crimp terminal via the base and the power feeding portion, so that the side portion may be thermally expanded. For this reason, the fixing of the core wire by the side portion is loosened, and a part of the core wire may be detached.

  A heater according to one aspect of the present invention includes a ceramic body, a heating resistor provided inside the ceramic body, a lead terminal provided on a surface of the ceramic body and connected to the heating resistor. A cable connected to the lead terminal, and the cable includes a plurality of core wires and a caulking metal fitting that holds the core wires in a bundled state. The caulking metal fitting includes a main portion and the main portion. And the pair of claws are caulked to hold the plurality of core wires, and the pair of claws and the lead terminal are welded.

  According to the heater based on one aspect of the present invention, by having the above-described configuration, it is possible to reduce the possibility that the fixing of the core wire by the claw portion becomes loose. As a result, the long-term reliability of the heater can be improved.

It is the schematic which shows the heater concerning one Embodiment of this invention. It is a perspective view which shows a cable among the heaters shown in FIG. It is a permeation | transmission perspective view which shows a cable and a lead terminal among the heaters shown in FIG. It is an enlarged view which shows a cable among the heaters shown in FIG. It is a cross-sectional view which shows a cable and a lead terminal among the heaters shown in FIG. It is an enlarged view which shows a cable among the heaters of a modification. It is a cross-sectional view which shows a cable and a lead terminal among the heaters of a modification.

  As shown in FIG. 1, the heater 10 of the present embodiment includes a ceramic body 1, a heating resistor 2 provided in the ceramic body 1, and a heating body 2 provided on the surface of the ceramic body 1. A connected lead terminal 3 and a cable 4 connected to the lead terminal 3 are provided. The heater 10 is used for, for example, a gas range, an in-vehicle heating device, an oil fan heater, a glow plug, or the like.

  The ceramic body 1 is a member in which the heating resistor 2 is embedded. The ceramic body 1 has, for example, a rod shape. Examples of the rod shape include a columnar shape and a quadrangular prism shape. The ceramic body 1 is made of an electrically insulating ceramic such as insulating ceramic, nitride ceramic, or carbide ceramic. Specifically, the ceramic body 1 is made of alumina ceramic, silicon nitride ceramic, aluminum nitride ceramic, silicon carbide ceramic, or the like.

The ceramic body 1 made of silicon nitride ceramic can be obtained by the following method. Specifically, for example, 5 to 15% by mass of a rare earth element oxide such as Y ₂ O ₃ , Yb ₂ O ₃ or Er ₂ O ₃ as a sintering aid with respect to silicon nitride as a main component; the amount of SiO ₂ contained in the _Al 2 _{O 3} and sintering of 5-5% by weight amount such that 1.5 to 5 wt% is mixed SiO ₂ that has been adjusted. And the ceramic body 1 which consists of silicon nitride ceramics can be obtained by baking at the temperature of 1650-1780 degreeC after shape | molding in a predetermined shape. For the firing, for example, hot press firing can be used.

  When the shape of the ceramic body 1 is a rod shape, more specifically, when the shape is a quadrangular prism shape, the length of the ceramic body 1 is set to 20 to 100 mm, for example. Moreover, the cross section of the ceramic body 1 is set to a square having a thickness of 1 to 6 mm and a width of 2 to 40 mm, for example.

  The heating resistor 2 is a member that generates heat when a voltage is applied thereto. The heating resistor 2 is embedded at least on the tip side of the ceramic body 1. When a voltage is applied to the heating resistor 2, a current flows and the heating resistor 2 generates heat. The heat generated by this heat generation is transmitted through the inside of the ceramic body 1, and the surface of the ceramic body 1 becomes high temperature. And a to-be-heated material can be heated when heat | fever transfers with respect to a to-be-heated material from the surface of the ceramic body 1. FIG. Examples of the object to be heated include light oil supplied to the interior of an automobile diesel engine, water for warm water heating, and the like.

  The heating resistor 2 has a folded portion on the tip side of the ceramic body 1, and both ends are drawn out to the side surface of the ceramic body 1. The heating resistor 2 contains, for example, a carbide such as tungsten (W), molybdenum (Mo), or titanium (Ti), nitride, silicide, or the like as a main component. When the ceramic body 1 is made of silicon nitride ceramics, the main component of the heating resistor 2 may be made of tungsten carbide. Thereby, the thermal expansion coefficient of the ceramic body 1 and the thermal expansion coefficient of the heating resistor 2 can be brought close to each other.

The lead terminal 3 is provided on the surface of the ceramic body 1 and connected to the heating resistor 2. The lead terminal 3 is provided to supply power to the heating resistor 2 together with the cable 4. The lead terminal 3 is connected to an external power source together with the cable 4. The lead terminal 3 is, for example, a rod-shaped member. The cross-sectional shape of the lead terminal 3 is, for example, a circular shape or a rectangular shape. The lead terminal 3 is made of, for example, iron or nickel.

  The cable 4 is a member for supplying power to the heating resistor 2 together with the lead terminal 3. The cable 4 is connected to the lead terminal 3. The cable 4 includes a plurality of core wires 41 and caulking fittings 42 that hold the core wires 41 in a bundled state. Since the cable 4 includes the plurality of core wires 41, durability when a large current flows in a state where the cable 4 is bent is improved. This is because when the cable 4 is bent, a plurality of core wires 41 bend while shifting their positions, so that a bent portion where heat generation is likely to occur can be shifted. In addition, since the surface area can be increased by having the plurality of core wires 41, the high-frequency waves transmitted on the surface portion are easily propagated. Therefore, when a large current is input as a pulse signal, it is possible to reduce the loss at the rising portion of the pulse composed of high frequency components.

  As shown in FIG. 2, the caulking metal fitting 42 has a main portion 43 and a pair of claw portions 44 extending from the main portion 43 and holds the plurality of core wires 41 by caulking the pair of claw portions 44. For example, the main portion 43 may have a flat plate shape or a curved shape of a plate-like member.

  In the heater 10 of the present embodiment, the main portion 43 has a shape obtained by bending a plate-like member, and the inner circumference and the outer circumference are curved in an arc shape. The pair of claw portions 44 extends from the main portion 43 so as to be continuous and is bent toward the inside of the main portion 43. The plurality of core wires 41 are located in a space surrounded by the main portion 43 and the pair of claw portions 44, and are fixed by being sandwiched between the main portion 43 and the pair of claw portions 44. The core wire 41 is made of a metal material such as silver, gold, or nickel. Moreover, the surface of the core wire 41 may be further covered with copper, silver, gold, or the like. The caulking metal fitting 42 is made of, for example, a metal material such as nickel, iron, or copper.

  In the heater 10 of this embodiment, as shown in FIGS. 3 and 4, the pair of claw portions 44 and the lead terminals 3 are welded. As a result, even if the pair of claws 44 are loosened and opened when the heat generated in the heater 10 is transmitted to the pair of claws 44, the pair of claws 44 and the lead terminals 3 are welded. Opening of the claw part 44 can be reduced. Thereby, the possibility that the fixing of the core wire 41 by the claw portion 44 may be loosened can be reduced. As a result, the long-term reliability of the heater 10 can be improved.

  Furthermore, in the heater 10 of the present embodiment, as shown in FIG. 3, the lead terminal 3 is provided so as to extend between the pair of claw portions 44. In other words, the pair of claw portions 44 are provided so as to extend in a direction perpendicular to the caulked direction. Thereby, since the area | region where the lead terminal 3 and a pair of nail | claw part 44 are welded can be made wide, the possibility that the fixation of the core wire 41 by the nail | claw part 44 may become loose can be reduced.

  Moreover, as shown in FIG. 5, the core wire 41 and the lead terminal 3 may be welded. Thereby, since welding with the lead terminal 3 and the cable 4 can be performed firmly, when external force is added, a possibility that the lead terminal 3 may remove | deviate from the cable 4 can be reduced.

  As shown in FIG. 6, the entire pair of claw portions 44 and the lead terminals 3 may be welded when viewed in the axial direction of the plurality of core wires 41. In other words, the lead terminals 3 arranged along the axial direction of the plurality of core wires 41 may be welded over the entire axial direction of the pair of claw portions 44. Thereby, since the area | region where the lead terminal 3 and a pair of nail | claw part 44 are welded can be made wide, the possibility that the fixation of the core wire 41 by the nail | claw part 44 may become loose can be reduced.

  Further, as shown in FIG. 7, at least a part of the lead terminal 3 may enter between the pair of claw portions 44. The term “between the pair of claw portions 44” here means between the ridge portions located inside the respective end surfaces of the pair of claw portions 44. The fact that at least a part of the lead terminal 3 is inserted between the pair of claw portions 44 means that one part of the lead terminal 3 is located inside the line segment connecting the ridge portions of the pair of claw portions 44 when viewed in cross section. It means that the part has entered. Thereby, the lead terminal 3 and the pair of claws 44 are welded in a state where the lead terminal 3 enters between the pair of claws 44, thereby further strengthening the welding between the lead terminal 3 and the cable 4. Can be done. Thereby, when external force is added, the possibility that the lead terminal 3 may come off from the cable 4 can be reduced.

  Further, the pair of claws 44 may be caulked with the lead terminal 3 entering between the pair of claws 44. The lead terminal 3 and the pair of claws 44 are welded in a state where a force sandwiching the lead terminal 3 with respect to the pair of claws 44 is applied, so that the lead terminal 3 and the cable 4 are joined more firmly. it can.

1: Ceramic body 2: Heating resistor 3: Lead terminal 4: Cable 41: Core wire 42: Caulking fitting 43: Main part 44: Claw part 10: Heater

Claims (4)

A ceramic body, a heating resistor provided inside the ceramic body, a lead terminal provided on the surface of the ceramic body and connected to the heating resistor, and a cable connected to the lead terminal Has
The cable includes a plurality of core wires and a caulking metal fitting that holds the core wires in a bundled state. The caulking metal fitting has a main portion and a pair of claw portions extending from the main portion, and the pair of claw portions are It is caulked and holds the plurality of core wires,
The heater, wherein the pair of claw portions and the lead terminal are welded.   The heater according to claim 1, wherein the plurality of core wires and the lead terminals are welded.   3. The heater according to claim 1, wherein when viewed in the axial direction of the plurality of core wires, the entire pair of claw portions and the lead terminal are welded.   The heater according to any one of claims 1 to 3, wherein at least a part of the lead terminal is inserted between the pair of claws.

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