JP2775998B2 - Electric water heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a connection configuration of a temperature detection unit used for an electric water heater or the like.

2. Description of the Related Art Conventionally, a connection configuration of a temperature detection unit of an electric water heater of this type is as shown in FIG. That is, a heating element 31 is provided at the bottom of the container 30, and a temperature detection unit 33 is brought into contact with the center of the bottom of the container 30, and the signal of the temperature detection unit 33 is supplied to the substrate of the control unit 34 of the electric water heater by the lead wire 35. To the connector 36. The temperature detection unit 33 uses a holding spring 37, and a heat shield plate 38.
The control unit 34 is configured to be mounted on the cover 41 via the mounting bracket 40.

In such a conventional configuration, a heating element 31 is provided on the bottom surface of the container 30.
Since the bottom surface of the container 30 has a high temperature, the heat sensing element 33 receives heat from the heating element 31 and the temperature sensing characteristics of the temperature detecting unit 33 are increased unless the heat treatment is performed on the lead wires 35 of the temperature detecting unit 33. May change. Also, this lead wire 35
Fixation so as not to touch the high temperature part, or
It is necessary to protect the lead wire 35 so that the lead wire 35 does not touch the edge of the end face of the metal component and is worn by vibration, and the insulation coating is not broken to cause insulation failure. In order to prevent such damage to the lead wire 35, the lead wire 35 is fixed and protected by, for example, hooking the lead wire 35 to a part of the cover 41. Therefore, it took a long time to assemble the lead wires. In addition, when the connector 36 is inserted into the connector 36 on the board side, the insertion is incomplete and the connector floats, resulting in poor contact.

Also, the temperature detection unit 33 is held on the heat shield plate 38 side by a spring.
Since the control unit 34 is mounted, the lead wire 35 and the connector 36 need to be fixed when the control unit 34 is mounted.

Further, the temperature detection unit 33 is attached by
Is mounted with screws, so the temperature detection unit
There was a problem that it took time to attach 33.

The present invention solves such a problem, and realizes a connection operation in which the connection operation between the temperature detection unit and the substrate is simple and can be surely performed, furthermore, no stress is applied to the circuit board, and the connection effect is large. It is intended for.

Means for Solving the Problems To achieve this object, an electric water heater according to the present invention comprises:
A heating element provided at the bottom of the container that contains the liquid, a temperature detection unit that includes a temperature detection unit and a terminal, and is brought into contact with the bottom of the container; a control unit that controls the temperature detection unit; and a container. And a board on which the electric components of the control unit are mounted, and the terminals of the temperature detection unit are directly extended and fitted to the terminal receivers provided on the board, and are directly extended from the temperature detection unit. A guide pin for guiding the inserted terminal is an electric water heater provided in the temperature detection unit.

Further, the terminals of the temperature detection unit are formed in a shape that is easily elastically deformed.

Further, the terminal of the temperature detection unit is provided with a portion for regulating the insertion depth into the terminal receiver.

The above-described electric water heater of the present invention directly connects the temperature detection unit and the temperature control unit without using a lead wire, and performs positioning when the terminal is inserted by the guide pins and fixing of the position after the terminal is inserted. .

In addition, when inserting the terminal into the terminal receiving portion of the control unit or after the insertion, the terminal itself to be inserted is elastically deformed so as to prevent mechanical stress or thermal stress from being applied to the substrate, thereby relaxing various stresses. .

Further, when the terminal is inserted into the terminal receiver, the insertion depth is regulated by a position regulating portion of the terminal.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, a liquid is accommodated in a container 2 having a heating element 1, and the liquid in the container 2 is heated by the heating element 1. Below the heating element 1, a heat shield plate 3 for blocking the heat of the heating element 1 is provided. In addition, heat shield plate 3
An electric pump (not shown) and a thermal fuse (not shown) are attached to the power supply. Below the container 2, a control unit 5 composed of a control unit for controlling the water heating and the heat retention state of the electric water heater and a power supply unit is arranged.

The control electronic components 8 in the control unit 5 are mounted on a board 7, and the board 7 is covered by a cover 9. The temperature detecting unit 6 has a thermosensitive part 10 and a terminal extending downward.
The thermosensitive part 10 is composed of a thermosensitive element 12 such as a thermistor.
It is composed of Further, the temperature detection unit 6 has a terminal 11
And a guide pin 13 longer than the tip of the terminal 11 in the same direction.

Further, a connector 15 having a terminal receiver 14 for inserting the terminal 11 of the temperature detection unit 6 is provided on the substrate 7, so that the terminal 11 of the temperature detection unit 6 and the terminal receiver 14 are directly connected.

The substrate 7 has a pair of holes 16 corresponding to the guide pins 13 of the temperature detection unit 6. The terminal 11 has elasticity, and a substantially U-shaped insertion depth regulating portion 18 is provided in the middle thereof.

In the above configuration, the terminal 11 of the temperature detecting unit 6 is directly inserted into the terminal receiver 14 provided on the substrate 7 in advance. In this case, the guide pins 13 are inserted into the holes 16 of the substrate 7, and the terminals 11 are guided in alignment with the terminal receivers 14. Furthermore, the insertion depth regulating portion 18 provided on the terminal 11 hits the cover 9, and the insertion depth of the terminal 11 into the terminal receiver 14 is properly maintained. As described above, the temperature detection unit 6 is connected to the terminal receiver 14 without using a lead wire, and
The connection work is facilitated. Also, by assembling the container 2 above with the temperature detection unit 6 attached to the substrate 7, the heat-sensitive portion 10 of the temperature detection unit 6 is pressed against the bottom of the container 2. In this case, since the terminal 11 has elasticity, the substantially U-shaped insertion depth regulating portion 18 functions to assist the pressure contact. In addition, terminal 11
Is absorbed, and stable contact of the temperature detection unit 6 with the container 2 can be obtained even when there is thermal deformation.

FIG. 2 shows another embodiment of the present invention, in which the insertion depth regulating portion 18 of the terminal 11 comes into contact with the substrate 7. This device has the same function and effect as those shown in FIG.

The other embodiment of the present invention shown in FIG. 3 uses two guide pins 13, and furthermore, a pressing spring for pressing the heat-sensitive part 10 of the temperature detecting unit against the bottom 2 'of the container 2.
19 are provided.

According to this configuration, it is not necessary to impart elasticity to the terminal 11, so that the terminal 11 can be a straight rod-shaped terminal.
The guide for inserting the terminal 11 into the terminal receiver 14 can be ensured.

According to the present invention, as is apparent from the above description of the embodiment, when connecting the temperature detection unit to the connector of the electric control unit, the guide pin is inserted and guided before the terminal is inserted. Since the positioning is performed, a stress such that the terminal is bent is not applied.

Furthermore, since no stress is applied to the terminal receiver provided on the printed board, it is possible to prevent copper foil peeling of the printed board caused by applying stress to the soldered portion of the terminal receiver.

Also, the terminal is inserted in the direction of the soldering surface of the board, and
Since the bent insertion depth regulating portion of the terminal comes into contact with the printed circuit board or the heat shield plate, the terminal is necessarily inserted at a constant depth, and stable connection can be maintained.

Furthermore, since the pressurizing spring is provided between the cover covering the substrate and the detecting unit and pressed against the temperature detecting unit, the temperature detecting unit can be pressed against the bottom of the container without being affected by the space between the heat shield plate and the mounting state. . As a result, stable temperature detection becomes possible.

Further, there is an effect that work such as lead wire processing and screw tightening of the holding spring is eliminated, so that assembly can be simplified and the number of assembling steps can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of an electric water heater according to an embodiment of the present invention, FIGS. 2 and 3 are enlarged cross-sectional views of a main part of another embodiment of the present invention, and FIG. It is sectional drawing of a water heater. 2 ... container, 5 ... control unit, 6 ... temperature detection unit, 7 ... board, 10 ... heat sensitive part, 11 ... terminal, 13 ...
Guide pin, 14… Terminal receiver, 15… Connector, 18…
Insertion depth regulating part.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoharu Saito 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. -44923 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) A47J 27/21-27/64

Claims (3)

(57) [Claims] 1. A temperature detecting unit comprising a heating element provided at the bottom of a container for containing a liquid, a temperature detecting unit and a terminal, the temperature detecting unit being in contact with the bottom of the container, and controlling the temperature detecting unit. A control unit, and a board provided below the container, on which the electric components of the control unit are mounted, and wherein the terminals of the temperature detection unit are directly extended and fitted to a terminal receiver provided on the board, and the temperature is controlled. An electric water heater, wherein a guide pin for guiding insertion of a terminal directly extended from a detection unit is provided in the temperature detection unit. 2. The electric water heater according to claim 1, wherein the terminals of the temperature detecting unit are formed of an elastic material which is easily elastically deformed. 3. The electric water heater according to claim 1, wherein the terminal of the temperature detecting unit is formed with a substantially U-shaped restricting portion for restricting the insertion depth into the terminal receiver.