JPS6263850A - Humidity detecting element - Google Patents

Abstract

PURPOSE:To improve the workability for assembly, and to improve the reliability of a connecting part of a lead wire by providing a holding part on the tip of a pair of lead terminals which are attached by passing through an envelope. CONSTITUTION:A holding part 14a is provided on the tips, respectively, which are positioned in the inside of an envelope of a lead terminal 14. Holding of a humidity sensing element body and an electrical connection of the lead terminal 14 and an electrode 12 can be executed at the same time by only inserting the humidity sensing element body 11 in the holding part 14a of the tip of the lead terminal 14 which is attached to a housing 13 in advance. Accordingly, the workability is improved remarkably, and also the titled element abounds in the vibration resistance and the mechanical strength, therefore, the reliability is further improved than usual.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to improvements in humidity sensing elements.

[Technical background of the invention and its problems]

A porous sintered body made of, for example, a metal oxide is known as one of the humidity sensitive bodies. In such a humidity sensitive body, water molecules are easily adsorbed and desorbed on the surface of metal oxide particles inside the sintered body, and the electrical resistance value or capacitance value is determined depending on the amount of water molecules adsorbed.

For this reason, humidity can be detected by providing electrodes on both principal surfaces of the humidity sensing element to form a humidity sensing element and measuring the electrical resistance or capacitance between the electrodes.

Conventionally, the above-mentioned humidity sensing element was manufactured by forming a pair of electrodes by baking conductive paste etc. on both main surfaces of the humidity sensing element, and then connecting lead wires to each of these electrodes. has been done.

As methods for holding such a humidity-sensitive element, methods of directly holding the humidity-sensitive element with lead wires, or methods of holding the humidity-sensitive element using an envelope, etc. have been put into practical use or have been proposed. ing.

The method of holding directly with lead wires is as shown in Figure 4.
Electrode 2 is formed by baking conductive paste on both main surfaces of humidity sensing element 1.
．． After forming the electrode 2.2, the lead wire 3.3 is brought into contact with the electrode 2.2, and the periphery of the lead wire 3.3 is potted with the conductive paste used to form the electrode, and then baked to form the connection portion 4.2. 4, and the lead wire 3.3 is attached to a support member (not shown).

However, this method has a drawback that it has poor vibration resistance, and when a load is applied to the connecting portion 4.4 due to vibration, the mechanical and electrical connection tends to become uncertain.

Therefore, the humidity-sensitive element is held in an envelope, the lead wire connected to the electrode of the humidity-sensitive element is wound around the lead terminal attached to the envelope, and then connected by spot welding or soldering. A method has been proposed to do this.

This method has better vibration resistance than a method in which the electrodes are held directly by lead wires, and because almost no load is applied to the connection between the electrodes and the lead wires, reliability is significantly improved. However, as described above, it is necessary to carry out spot welding after winding the lead wire around the lead terminal, which has the drawback of extremely poor workability.

[Purpose of the invention]

The present invention has been made in order to eliminate the above-mentioned drawbacks, and aims to provide a humidity sensing element that improves the reliability of the lead wire connection and has excellent assembly workability.

[Summary of the invention]

In the humidity sensing element of the present invention, a portion of the electrodes of the humidity sensing element are extended to the periphery of the humidity sensing element, and the electrodes are partially formed so as not to face each other at the periphery of the humidity sensing element, and an envelope is formed. A holding portion is provided at the tip of the pair of lead terminals that are attached through the moisture sensing element body, and is configured to hold the peripheral edge of the moisture sensitive element body and to connect to one of the pair of electrodes, respectively. It is something.

According to such a humidity detecting element, the humidity sensing element is mechanically held by the holding portion of the lead terminal, and at the same time, the humidity sensing element can be sensed/! 11!
Since the electrodes of the element body and the lead terminals can be electrically connected easily, the workability of assembly is extremely good. Also,
The vibration resistance of the connection between the moisture sensitive element and the lead terminal is also excellent, and reliability can also be improved.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of a humidity sensing element body of a humidity sensing element according to the present invention. In FIG. 1, a pair of electrodes 12.12 are provided on both sides of the humidity sensitive body 11. These electrodes 1
2.12 is formed by baking conductive paste on both main surfaces of the humidity sensitive body 11. And these electrodes 1
2.12 occupies the central part of both main surfaces of the humidity sensitive body 11, and a part thereof extends to one side of the humidity sensitive body 11,
The extended portions are formed at different positions on the 42 sides and the bottom surface of the humidity sensitive body 11. Therefore, the portions of the electrodes 12.12 formed at the peripheral edge of the humidity sensitive body 11 do not face each other.

FIG. 2 is a perspective view showing a state in which the moisture-sensitive element shown in FIG. 1 is attached to a housing 13 constituting an envelope.

In FIG. 2, a pair of lead terminals 14, 14 are attached to one surface of the housing 13 so as to penetrate therethrough.

Holding portions 14a, 14a are provided at the tips of these lead terminals 14.14 located inside the envelope, respectively. These lead terminals 14.14 are held with one side of the humidity sensitive element sandwiched between the holding parts 14a, 14a at their tips, and are each connected to one of the electrodes 12.12 of the humidity sensitive element.

FIG. 3 shows the lid body 15 constituting the envelope from the state shown in FIG. 2.
FIG. 2 is a perspective view showing the external appearance of a humidity detection element according to the present invention assembled by fitting together. As shown in FIG. 3, the housing 13 and the lid 15, which constitute the envelope, each have ventilation holes 16,
... is provided to ensure ventilation inside and outside the envelope.

According to such a humidity detection element, the holding portion 14a at the tip of the lead terminal 14.14 attached to the T-shaped housing 13
, 14a, it is possible to simultaneously hold the humidity sensitive element and electrically connect the lead terminal 14.14 and the electrode 12.12. Therefore, workability is greatly improved, and since vibration resistance and mechanical strength are high, reliability is dramatically improved compared to the conventional method.

In the above embodiment, the envelope is composed of the casing 13 and the lid 15, but the present invention is not limited to this, and the envelope may be composed of only a frame, or may be a frame in which a filter is inserted. However, if the envelope consists of only a frame, there is a risk that fingers or protrusions may come into contact with the moisture-sensitive element and damage it during handling, and to avoid this, a filter may be attached to the frame. In addition to increasing the cost of the filter, it also takes time and effort to install the filter. On the other hand, if the envelope is composed of the housing 13 and the lid 15 as in the above embodiment, and the ventilation holes 16 are provided in the housing 13 and the lid 15 so that the two fit together, It is possible to prevent damage to the moisture-sensitive element body, and to ensure ventilation inside and outside the envelope without causing an increase in cost and man-hours unlike when using a filter.

Further, if the holding portions 14a, 14a of the lead terminals 14.14 are plated with gold, the reliability of the electrical connection with the electrodes 12.12 is further improved.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a humidity detection element that is easy to assemble and has high reliability.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a moisture-sensitive element body of a damp collapse detection cable f in an embodiment of the present invention, FIG. FIG. 3 is a perspective view showing the external appearance of a humidity sensing element according to an embodiment of the present invention, and FIG. 4 is a perspective view showing a conventional method of mounting a humidity sensing element. DESCRIPTION OF SYMBOLS 11... Humidity sensitive body, 12... Electrode, 13... Housing, 14... Lead terminal, 1.4 a... Holding part,
15... Lid body, 16... Ventilation hole. Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 4

Claims (3)

[Claims] (1) Humidity detection having a humidity sensing element consisting of a plate-shaped humidity sensing element and a pair of electrodes formed on both main surfaces of the humidity sensing element, and an envelope housing the humidity sensing element. In the element, a portion of the electrodes of the humidity sensing element are each extended to a peripheral edge of the humidity sensing element, and are formed so as not to face each other partially at the peripheral edge of the humidity sensing element, and are formed so as to penetrate through the envelope. A humidity sensing element, characterized in that a holding part is provided at the tips of a pair of attached lead terminals to hold the peripheral edge of the humidity sensing element body and to connect each to one of the pair of electrodes. . (2) The humidity detection element according to claim 1, wherein the envelope is composed of a housing and a lid, and a ventilation hole is provided in the housing and the lid. (3) The humidity detecting element according to claim 1, wherein the holding portion of the tip of the lead terminal connected to the electrode of the humidity sensitive element is plated with gold.