JPH0744982Y2 - Temperature sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a temperature sensor for detecting the temperature of fuel supplied to an engine of a vehicle, for example.

[Conventional technology]

Generally, temperature sensors as shown in FIGS. 4 and 5 are known.

In the figure, reference numeral 1 denotes a housing main body, and the housing main body 1 is formed in a generally cylindrical shape with a bottom and an outer shape in a substantially bolt shape. Here, the outer periphery of the housing body 1 is provided on the bottom lid portion 1A formed on one side portion and the other side portion, and after the resin mold 6 described later is fitted, the resin mold 6 is caulked. A mold fixing portion 1B for fixing and supporting the same, a bolt head 1C having a hexagonal cross section formed on the lower side of the mold fixing portion 1B, and a screw portion 1D formed on the lower side of the bolt head 1C. Has been done. Further, inside the housing body 1, a bottomed inner cylinder portion 1F in which a thermistor 2 which will be described later is accommodated is provided on the bottom surface 1E, and a stepped taper diameter is enlarged on the upper end side of the inner cylinder portion 1F. An O-ring accommodating step portion 1G that is formed and into which an O-ring 10 described later is inserted is provided. The housing body 1 is attached to a fuel flow path in the fuel supply pipe of the engine or the like, and the housing body 1 serves as a body ground.

Reference numeral 2 denotes a thermistor as a temperature sensitive element which is provided in the inner cylindrical portion 1F and is in contact with the bottom surface 1E via the conductive contact plate 3. The thermistor 2 is formed in a thick disk shape. Reference numeral 4 is a contact which is brought into contact with the upper side surface of the thermistor 2 and electrically connected thereto. The contact 4 is formed in a substantially columnar shape, and a spring receiving step portion 4A and a spring fitting convex portion 4B are formed on the upper side thereof. There is.

Reference numeral 5 denotes the housing body 1 from the opening side of the housing body 1.
On the other hand, a resin mold 6 as an insulating member is formed on the upper end side around the plug 5, which is a plug provided in an electrically insulated state. Then, the resin mold 6 is fitted into the mold fixing portion 1B of the housing body 1 and then the mold fixing portion 1B is fixed by caulking the mold fixing portion 1B. Is fixedly supported on the opening side of. Further, the plug 5 has an enlarged diameter step portion 5A formed in its middle portion for being fixed to the resin mold 6, and a spring receiving step portion 5B and a spring fitting convex portion 5C provided at the lower end portion.

Reference numeral 7 denotes a spring that is elastically provided between the contact 4 and the plug 5 and electrically connects the two to each other.
With the upper end supported by the plug 5, the lower end contacts the contact 4 and presses the contact 4 toward the thermistor 2. That is, the lower end of the spring 7 is press-fitted into the spring fitting convex portion 4B of the contact 4 while being rotated until it comes into contact with the spring receiving step portion 4A, and the upper end thereof is fitted into the spring fitting convex portion 5C of the plug 5 and the spring fitting convex portion 5C. The contact 4 is pressed into the receiving step portion 5B while being rotated until it comes into contact with the receiving step portion 5B, and presses the contact 4 toward the thermistor 2 side while electrically connecting the both.

A terminal plate 8 is embedded in the resin mold 6 and is electrically connected to the plug 5. The terminal plate 8 is connected to an external plus-side wiring (not shown).

Reference numeral 9 denotes a sleeve that is inserted into the inner cylindrical portion 1F of the housing body 1. The lower end portion of the sleeve 9 is bent inward, and the lower opening portion is formed to have a reduced diameter. The thermistor 2 is inserted. The upper end of the sleeve 9 extends in the inner tubular portion 1F to a position directly below the O-ring 10 and surrounds the thermistor 2, the contact 4, the lower end of the plug 5 and the spring 7, and these and the housing. It is insulated from the main body 1.

Reference numeral 10 is an O-ring provided on the O-ring receiving step 1G of the housing body 1, and the O-ring 10 is sandwiched between the O-ring receiving step 1G, the resin mold 6 and the plug 5.

The conventional temperature sensor configured as described above is assembled as follows.

First, in the pre-assembly step, in order to improve the assemblability, the lower end of the spring 7 is rotated into the spring fitting convex portion 4B of the contact 4 while being press-fitted until it abuts on the spring receiving step portion 4A. While rotating the upper end of 7 into the spring fitting convex portion 5C of the plug 5 until it comes into contact with the spring receiving step portion 5B, the contact 4, the plug 5 and the spring 7 are integrally assembled, and the plug 5 Fit the O-ring 10 on the outer circumference. A resin mold 6 is applied to the plug 5 while the terminal plate 8 is electrically connected.

Next, the thermistor 2 is attached to the inner tubular portion 1F of the housing body 1,
The contact plate 3 and the sleeve 9 are inserted and fitted, and the contact 4, the plug 5, the spring 7, the terminal plate 8 and the O-ring 10 which are integrally molded are inserted and fitted. Then, the resin mold 6 is fixedly supported on the housing body 1 by caulking the mold fixing portion 1B.

In the temperature sensor thus assembled, the threaded portion 1D of the housing body 1 is screwed into an insertion hole (not shown) provided in the fuel passage.

[Problems to be solved by the device]

By the way, in the above-mentioned conventional technique, when the both ends of the spring 7 are press-fitted into the contact 4 and the plug 5, the spring 7 scrapes the outer peripheral surface of each spring fitting convex portion 4B, 5C, so that burrs and abrasion powder (hereinafter, " Burr, etc.). Even if the burr or the like is generated, it is difficult to completely remove the burr or the like in the assembly process, and the burr or the like may remain in the inner cylindrical portion 1F of the housing body 1.

When burr or the like remains in the inner cylindrical portion 1F, the burr or the like drops to the thermistor 2 side or scatters from the upper end of the sleeve 9 to the outside of the sleeve 9 due to vibration from the outside of the engine or the like. On the other hand, burrs 11 and the like that have fallen downward enter between the thermistor 2 and the reduced diameter portion 9A of the sleeve 9 to short-circuit the contact plate 3 and the contact 4, or the side surface of the thermistor 2 and the contact plate 3 There is a problem in that the detection value of the sensor changes greatly due to short-circuiting between and, resulting in erroneous detection.

Further, burrs 12 scattered from the upper end of the sleeve 9 to the outside of the sleeve 9 come into contact with the housing body 1 while the O-ring 10 is held, and short-circuit between the housing body 1 and the plug 5 to cause false detection. There is a problem that is caused.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a temperature sensor capable of reliably preventing a failure due to a short circuit by capturing a burr or the like generated during assembly.

[Means for Solving the Problems]

The structure adopted by the present invention to solve the above-mentioned problems is a housing body which is formed in a bottomed shape and is held at ground potential, and a side surface abutting on the bottom portion of the housing body. A temperature element, a contact provided in contact with the other side surface of the temperature sensing element, and a plug provided in the opening of the housing body in an electrically insulated state from the housing body via an insulating member. A spring elastically provided between the plug and the contact and electrically connecting the plug and the contact; a sleeve provided in the housing body so as to surround the outer periphery of the spring; the housing body, the plug, and A temperature sensor comprising an O-ring provided so as to be sandwiched between insulating members, wherein the temperature-sensitive element is provided with a sleeve locking collar on the outer periphery thereof.
The sleeve is provided with an engaging portion for engaging with the flange portion of the temperature sensitive element on one side in the lengthwise direction, and is radially outwardly expanded on the other side in the lengthwise direction so that the housing main body and the O-ring are formed. A flange portion is provided so as to be sandwiched between and.

[Action]

With the above structure, even if burrs or abrasion powder is generated between the spring and the contact or between the spring and the plug, the temperature sensing element side is locked to the flange portion of the temperature sensing element and the collar portion via the locking portion. And the burrs and the like to prevent the burrs from falling to the bottom of the housing body. Furthermore, burrs that try to scatter from the upper end of the sleeve to the outside of the sleeve are prevented from entering the housing body side by the flange portion that is tightly sandwiched between the housing body and the O-ring, and erroneous detection by the temperature sensor is prevented. To prevent.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. Since the entire structure of the temperature sensor of the present embodiment is almost the same as that of the above-mentioned conventional temperature sensor, the same members are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 21 is a thermistor as a temperature sensing element of this embodiment,
The thermistor 21 is formed in a thick disk-like or columnar shape as a whole, and a flange portion 21A for engaging with an engaging portion 22A of a sleeve 22 described later is provided on the outer peripheral portion of the upper end thereof.

Reference numeral 22 denotes the sleeve of the present embodiment, which is formed on the lower side, which is one side in the length direction of the sleeve 22, by bending inward and reducing the diameter so as to be locked to the collar portion 21A of the thermistor 21. A stop 22A is provided. A flange portion 22B formed by bending and expanding outward is provided on the other side in the length direction of the sleeve 22. The flange portion 22B is formed by the O-ring accommodating step portion 1G and the O-ring 10 of the housing body 1. It is inserted between and and is sandwiched between these.

The temperature sensor configured as described above is assembled as follows.

First, as in the prior art, in the preliminary assembly process, the contact 4 and the plug 5 having the resin mold 6 are integrally assembled beforehand via the spring 7, and the O-ring 10 is attached to the plug 5. Put it on.

Next, the assembly assembled as described above is inserted into the sleeve 22 from the thermistor 21, and the flange portion 21A of the thermistor 21 is locked to the locking portion 22A of the sleeve 22 and locked with these flange portions 21A. The portion 22A and the portion 22A are closely joined to each other to the extent that burr and the like can be prevented from entering. Then, the thermistor 21 and the sleeve 22 are inserted into the inner cylindrical portion 1F of the housing body 1, the flange portion 22B of the sleeve 22 is brought into contact with the O-ring accommodating step portion 1G, and the flange portion 22B accommodates the O-ring 10 and the O-ring. It is pressed so as to be sandwiched between the step portion 1G.

Further, in this state, the mold fixing portion 1B is caulked to fix and support the resin mold 6 on the housing body 1.

The temperature sensor of this embodiment is assembled as described above,
When joining the spring 7 and the contact 4 or the spring 7 and the plug 5, respectively, burrs and abrasion powder may be generated between them. However, in the present embodiment, on the thermistor 21 side, since the collar portion 21A of the thermistor 21 is tightly locked via the locking portion 22A of the sleeve 22, burrs and the like generated as described above are The bottom surface 1E in the housing body 1 is captured between the collar portion 21A and the locking portion 22A.
It is prevented from falling to the side.

On the other hand, burrs or the like that try to scatter from the upper end of the sleeve 22 to the outside of the sleeve 22 are captured by the flange portion 22B sandwiched between the housing body 1 and the O-ring 10, and are prevented from entering the housing body 1 side. It

Thereby, between the housing body 1 and the contact 4,
It is possible to reliably prevent erroneous detection by the temperature sensor due to a short circuit between the housing body 1 and the thermistor 21, or between the housing body 1 and the plug 5. As a result,
The reliability of the temperature sensor is improved.

In the present embodiment, the thermistor 21 is used as the temperature sensitive element, but another temperature sensitive element such as a posistor may be used.

[Effect of device]

As described in detail above, according to the present invention, a flange portion for locking the sleeve is provided on the outer peripheral portion of the temperature sensing element, and the locking portion for locking the collar portion of the temperature sensing element on one side in the length direction of the sleeve. Since a flange portion is provided on the other side in the length direction so that the diameter is expanded outward and is sandwiched between the housing body and the O-ring, the temperature difference between the housing body and the contact is It is possible to reliably prevent erroneous detection by the temperature sensor due to a short circuit between the element or between the housing body and the plug, and reliability of the temperature sensor is improved.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention. FIG. 1 is an enlarged semi-longitudinal sectional view showing a main part of a temperature sensor, FIG. 2 is a perspective view showing a thermistor, and FIG. 3 shows a sleeve. Perspective view,
4 and 5 relate to the prior art, FIG. 4 is a semi-longitudinal sectional view showing the entire structure of a temperature sensor according to the prior art, and FIG. 5 is an enlarged semi-longitudinal sectional view showing the main part of FIG. . 1 ... Housing body, 4 ... Contact, 5 ... Plug, 6 ... Resin mold, 7 ... Spring, 10 ... O
Ring, 21 …… thermistor, 21A …… collar part, 22 …… sleeve, 22A …… locking part, 22B …… flange part.

Claims (1)

[Scope of utility model registration request] 1. A housing body which is formed in a bottomed shape and is held at an earth potential, a temperature-sensitive element whose one side surface is in contact with a bottom portion of the housing body, and the other side surface of the temperature-sensitive element. A contact provided in contact with the housing, a plug provided in the opening of the housing body in a state of being electrically insulated from the housing body via an insulating member, and an elastic member between the plug and the contact. A spring provided in the housing body to electrically connect the two to each other, a sleeve provided in the housing body so as to surround the outer periphery of the spring, and a spring sandwiched between the housing body, the plug and the insulating member. In the temperature sensor including the O-ring, a sleeve locking flange is provided on the outer circumference of the temperature sensing element, and the sleeve is engaged with the flange of the temperature sensing element on one side in the length direction. Let it stop Provided with a locking portion, a temperature sensor, characterized in that a flange portion so as to be sandwiched between the housing body and the O-ring diametrically enlarged radially outward on the other side in the longitudinal direction.