JPS64578Y2 - - Google Patents

Description

[Detailed explanation of the idea] B Industrial application field The present invention relates to a waterproof structure for a temperature sensor.

(b) Prior art In a temperature sensor, the temperature sensing element is housed in a case, but when this is housed, the open end of the case, which is the entrance to the transmission line, is sealed from above to prevent short circuits due to condensation inside the case. At the same time, it is necessary to firmly fix the transmission line and the case.

For this reason, conventionally, as shown in FIG.
From the open end side, a rubber bush 4 is inserted and an adhesive 5 is filled and stored, and as shown in FIG. The case 3 is stored from the opening side, the intermediate ring 6 is caulked and fixed to the open end of the case 3, the cap 7 is screwed to the outer end of the intermediate ring 6, and the case 3 is filled with grease 8. An O-ring 9 is interposed between the intermediate ring 6 and the transmission line 1, and the intermediate ring 6 and the cap 7 are bonded with an adhesive 10a, and the cap 7 and the transmission line 1 are bonded with an adhesive 10b. be. However, in the conventional structure shown in FIG. 1, there are concerns about the adhesion of the adhesive 5 to the case 3 and the presence or absence of communicating bubbles. Furthermore, in the conventional structure shown in Fig. 2,
Its structure is complex, requiring time and effort to assemble, and the consistency of the filled grease 8 changes due to temperature changes, making the deformation pressure of the O-ring 9 unstable, and furthermore, the adhesive strength of the adhesives 10 and 11 is unstable. There is.

C. Purpose of the invention In view of the foregoing, the present invention has been developed to make it possible to reliably close the open end of the case with a rubber bushing and a cap without using the adhesives and greases described above. The purpose of this invention is to eliminate concerns about the adhesive strength of the O-ring and deformation pressure of the O-ring due to grease, and to simplify the structure thereof.

D. Structure of the Invention In order to achieve the above-mentioned object, the present invention forms a flare 11a protruding toward the outer circumference at the opening of the cylindrical case 11 with a bottom, and a transmission line 1 located in the opening.
A rubber bush 13 is attached to the outer periphery of the flare 11.
A cap 15 formed into a cylindrical cylinder with a contracting rear end is fitted so as to come into contact with the rear surface of the rubber bushing 13, and the cap 15 is fitted onto the outer periphery of the rubber bushing 13, so that the cap 15 is positioned on its expanding side. By pressing forward, the front end edge 15a provided on the expanded side is caulked and fixed to the flare 11a of the case, and the case 11 is fixed by the restoring elastic force of the compressively interposed rubber bush 13.
It is characterized in that the open end side is sealed.

E. Example Next, an example of the present invention shown in FIG. 3 will be described.

Reference numeral 11 denotes a cylindrical case with a bottom, and a flare 11a is formed at the open end of the case. 12 is case 11
The transmission line of the temperature sensing element housed inside, 13 is the transmission line 1
A rubber bush fitted to the outer periphery of 2, made of a material that can withstand temperatures higher than the maximum operating temperature.For example, if the temperature sensing element is a copper resistance thermometer, diode, or transistor, use ethylene propylene rubber, or use a thermistor. In this case, use ethylene propylene rubber or fluoro rubber. The rubber bush 13
The shape of the rear outer peripheral surface 13 is as shown in FIG.
a is formed as a tapered surface that reduces at the rear, and a protrusion 13b that is press-fitted into the case 11 at the front,
Furthermore, an insertion hole 13c for the transmission line 12 is formed in the center. 14 is a sleeve crimped around the outer periphery of the transmission line 12, and 15 is a cap, which is formed into a cylindrical cylinder that shrinks at the rear. A rubber bush 13 interposed within the cap 15 is crimped onto the transmission line 12.
Next, the work of assembling each member will be explained. First, the cap 15 is passed through the transmission line 12, and the rubber bush 13 is also passed through the cap 15 so as to be positioned in front of the cap 15. Furthermore, the sleeve 14 is crimped and fixed to the outer periphery of the transmission line 12 at a predetermined position.
And the transmission line 1 together with the temperature sensing element and the sleeve 14
2 is housed in the case 11, and the cap 15 is pushed forward along the axial direction of the transmission line 12, so that the protrusion 13b of the rubber bushing 13 is inserted into the case 1.
Press fit into opening 1. As a result, the rubber bush 13 is pressed and compressed by the tapered part of the cap 15, and the rear end 13d protrudes from the rear part of the cap 15. Due to the restoring elastic force of the rubber bush 13, the inner surface of the insertion hole 13c is inserted into the transmission line 1.
2, and the outer peripheral surface 13a is sealed to the cap 1.
5 to sealingly crimp it. After this press fit, cap 1
5 to the front edge 15a of the case 11.
Fold it to the front of part a and swage it. This maintains the compressed state of the rubber bush 13.

F. Effects of the invention As described above, according to the invention, the open end of the case 11 is sealed with the rubber bush 13 compressed and interposed between the transmission line 12 and the cap 15. Concerns about adhesive strength and deformation of the O-ring due to grease are eliminated, and the repulsive force of the rubber bushing 13 allows for reliable sealing and waterproofing without any concerns. In addition, the structure is simple and can be formed at low cost, making it practically effective.

[Brief explanation of drawings]

1 and 2 are sectional views showing two examples of conventional structures, FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG. 4 is a sectional view of a rubber bushing. 11...Case, 11a...Flare, 12...
...Transmission line, 13...Rubber bushing, 13a...Tapered rear outer peripheral surface, 13b...Protrusion, 13c...
...insertion hole, 14...sleeve, 15...cap, 15a...front edge.

Claims (1)

[Scope of utility model registration request] A flare 11a protruding to the outer periphery is formed at the opening of the bottomed cylindrical case 11, and a rubber bush 13 is fitted around the outer periphery of the transmission line 12 located at the opening so as to abut against the rear surface of the flare 11a. A cap 15 formed into a conical cylinder that contracts at the rear is fitted onto the outer periphery of the rubber bushing 13, and the cap 15 is pressed forward, which is the expansion side, and is provided on the expansion side. A waterproof structure for a temperature sensor characterized in that the front edge 15a is caulked and fixed to the flare 11a of the case, and the open end side of the case 11 is sealed by the restoring elastic force of the compressively interposed rubber bush 13. .