JPH05296852A - Mounting structure of sensor - Google Patents

Abstract

PURPOSE:To unite a pipe and a sensor into one body with high sealing efficiency. CONSTITUTION:The mounting structure of a sensor is constituted of a pipe main body 1 which has a stage 12 in the outer peripheral surface thereof and a mounting hole 13 penetrating the stage, a sensor 2 having a flange part 20 and inserted into the mounting hole 13, a ring-shaped elastic sealing materials 3 interposed between the flange part 20 and the stage 12, and a resin mold part 4 formed by injection molding. The elastic sealing material 3 is held and sealed between the flange part 20 and the stage 12 by the injection pressure when the resin mold part 4 is molded and the contraction stress subsequent to the molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a sensor on a pipe material. INDUSTRIAL APPLICABILITY The present invention can be used, for example, when mounting a water temperature sensor on an engine cooling water flow path of an automobile.

[0002]

2. Description of the Related Art A water temperature sensor is provided in a cooling water passage in order to know the temperature of an automobile engine cooling water. As this water temperature sensor, a thermistor whose electric resistance value changes according to temperature is housed in a container, or a reed switch whose contacts open and close when the water temperature exceeds a certain temperature is generally used. Then, for example, as shown in FIG. 4, a male screw 102 is formed on the outer circumference of a metal container 101 having a reed switch 100, and a pedestal portion 20 provided on a pipe 200 is formed.
It is attached by screwing to a mounting hole 202 penetrating the inside of the pipe 200 from 1.

[0003]

However, in the above mounting structure, the male screw 102 and the female screw of the mounting hole 202 are required to have high accuracy in order to obtain a high sealing property, and the metal container 101 and the pipe 200 are manufactured. A lot of man-hours. Further, when assembling to an automobile body, the number of parts is large and the assembling man-hour is also large, resulting in an increase in cost. Further, since it is necessary to form the male screw 102, the metal container 101 has a thick wall and is heavy.

The present invention has been made in view of such circumstances, and an object thereof is to integrate a pipe and a sensor with a high sealing property.

[0005]

SUMMARY OF THE INVENTION A sensor mounting structure according to the present invention which solves the above-mentioned problems is provided with a pipe base having a pedestal on a part of its outer peripheral surface and having a mounting hole penetrating inward from the surface of the pedestal. A sensor that has a flange with an outer diameter larger than the hole diameter and is inserted into the mounting hole from the pedestal, a ring-shaped elastic seal material that is interposed between the sensor flange and the pedestal, and wraps the pedestal. As described above, it is made up of a resin molding part formed by injection molding on the surface of the pipe base, and the elastic sealing material is sandwiched between the flange part and the pedestal part by the injection pressure during molding of the resin molding part and the contraction stress after molding. It is characterized by being sealed.

[0006]

To form the mounting structure of the present invention, first, a ring-shaped elastic seal material is arranged around the mounting hole of the pedestal portion of the pipe base, and the sensor is inserted into the mounting hole. Then, with the flange portion of the sensor in contact with the elastic seal material, the entire pedestal portion is placed in the mold. When the molten resin is injected around the pedestal, the flange portion of the sensor presses the elastic sealing material against the surface of the pedestal with the injection pressure, and an elastic reaction force is generated in the elastic sealing material. When the molten resin is solidified in that state, stress due to contraction is further generated, and the elastic seal material is further compressed. As a result, the elastic sealing material makes a strong elastic contact with the flange portion and the pedestal portion, and a high sealing property is obtained.

That is, in the mounting structure of the present invention, the flange portion of the sensor is covered with the resin molding portion, and the elastic sealing material is formed between the flange portion and the pedestal portion by the injection pressure during molding of the resin molding portion and the contraction stress after molding. Compressed between. This surely prevents the fluid flowing in the pipe base body from leaking from the mounting hole to the outside, and a high sealing property is obtained.

[0008]

That is, according to the sensor mounting structure of the present invention, since the sensor has a high sealing property and is integrated with the pipe base, it can be assembled to the vehicle body as an assembly component. Therefore, the number of assembling steps is remarkably reduced, and the cost can be reduced. Further, since the sensor does not need a thick metal container as in the conventional case, the weight can be reduced.

Further, the ends of the hose inserted into the pipe can be integrally joined with the resin molding portion. By doing so, the hose, the pipe and the sensor are integrated into an assembly part, and the number of assembling steps is further reduced.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples. (Embodiment 1) FIG. 1 shows an embodiment of the present invention. The mounting structure of this embodiment includes a pipe base 1, a water temperature sensor 2,
The elastic sealing member 3, the resin molding portion 4, and the hose 5 are included.

The pipe base 1 is an aluminum flanged pipe having a flange portion 10 at one end and a ring-shaped convex portion 11 for locking a hose formed at the other end, through which the hose 5 is inserted. A cylindrical pedestal 12 whose axis is orthogonal to the axis of the pipe base 1 is formed in a part of the intermediate portion. The pedestal portion 12 is formed with an attachment hole 13 extending in the axial direction thereof and penetrating the side wall of the pipe base body 1.

The water temperature sensor 2 has a flange portion 20 at the opening.
With a bottomed cylindrical metal sensor unit 21, and the sensor unit 21
A reed switch 22 enclosed therein, an electrically insulating connecting portion 23 fixed to the opening side of the sensor portion 21, and a terminal 24 electrically connected to the exposed reed switch 22 in the connecting portion 23. It consists of The other pole of the reed switch 22 is connected to the sensor unit 21,
Since 1 is in contact with the pipe base 1, it is connected to the ground potential from the automobile body. Then, the sensor portion 21 is inserted into the mounting hole 13 so as to be exposed inside the pipe base body 1 and contact the engine cooling water flowing in the pipe base body 1.

The elastic seal material 3 is an O-ring, is interposed between the pedestal portion 12 and the flange portion 20 and compressed, and elastically contacts the pedestal portion 12 and the flange portion 20 to exert a large sealing force. The resin molding portion 4 is formed by injection molding from a polyamide resin, covers the entire pedestal portion 12, and covers the end portion of the rubber hose 5 inserted into one end of the pipe base body 1 in a tubular shape.

This mounting structure was manufactured as follows. First, the hose 5 is inserted through the pipe base 1. Next, the elastic sealing material 3 is placed around the mounting hole 13 of the pedestal portion 12, the sensor portion 21 of the water temperature sensor 2 is inserted into the mounting hole 13, and the elastic sealing material 3 is formed between the flange portion 20 and the pedestal portion 12.
Sandwich. Then, in this state, the end portion of the hose 5 inserted into the pipe base body 1, the portion including the pedestal portion 12 and the flange portion 20 of the water temperature sensor 2 are arranged in the cavity of the mold,
The molten polyamide resin is injected to form the resin molding portion 4. At this time, the flange portion 20 is controlled by the injection pressure and the resin molding portion 4.
The elastic sealing member 3 is pressed by the contraction stress at the time of solidification in the direction approaching the pedestal portion 12, and the elastic sealing member 3 and the pedestal portion 1
It is compressed between the two and generates an elastic reaction force. In addition, the end of the hose 5 is caused by the injection pressure and the contraction stress at the time of solidification, so that the pipe base 1
It is pressed by and is clamped and fixed between the resin molding portion 4 and the pipe base 1.

Therefore, according to the mounting structure of the present embodiment, since the elastic sealing member 3 is in strong elastic contact with the flange portion 20 and the pedestal portion 12, the leakage of the cooling water from the mounting hole 13 is surely prevented. .. Further, since the pipe base 1, the water temperature sensor 2, and the hose 5 can be supplied as an integrally assembled assembly component, the number of assembling steps to the vehicle body can be significantly reduced. (Second Embodiment) FIG. 2 shows a second embodiment of the present invention. Although the hose 5 is integrally covered with the resin molding portion 4 in the above embodiment, this embodiment shows the case where the resin molding portion 4 is formed without the hose. In the case where the hose 5 is also covered, the resin molding portion 4 is formed because a part covering the hose 5 once is formed.
Although there was no possibility that the resin would come off from the pipe base 1, the resin molding portion 4 might fall off only by covering the pedestal portion 12.

In order to ensure the integrity of the resin molding portion 4 and the pipe base body 1, it is conceivable to form the resin molding portion 4 into a substantially cylindrical shape that surrounds the pipe base body 1, for example. However, in that case, a large amount of resin is required and the outer diameter of the pipe base body 1 is increased, which may cause a problem in terms of arrangement space. Therefore, in this embodiment, as shown in FIG. 2, a ring-shaped groove portion 14 is formed on the side peripheral surface of the pedestal portion 12 so as to make one round of the pedestal portion 12. As a result, the resin molding part 4
Since the groove portion 14 is filled in the groove portion 14 and is undercut, the resin molded portion 4 is prevented from falling off the pedestal portion 12. (Embodiment 3) In the above two embodiments, the surface of the pedestal portion 12 was almost flat because the portion where the elastic sealing material 3 was disposed was slightly recessed, but as shown in FIG. It is also preferable to form a thick ring-shaped bank 15 on the pedestal 12 having an inner diameter larger than the outer diameter of 20. By doing so, even if the elastic seal portion 3 is compressed and deforms to protrude to the outside of the flange portion 20, the gap between the outer peripheral end surface of the flange portion 20 and the inner peripheral surface of the bank portion 15 is filled at that portion. Can be configured to be. Therefore, the sealing property is further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mounting structure according to an embodiment of the present invention.

FIG. 2 is a sectional view of a mounting structure according to a second embodiment of the present invention.

FIG. 3 is a sectional view of an essential part of a mounting structure according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional mounting structure.

[Explanation of symbols]

1: Pipe base 2: Water temperature sensor
3: Elastic seal material 4: Resin molding part 5: Hose 1
2: Pedestal part 13: Mounting hole 14: Groove part 2
0: Flange part

Claims (1)

[Claims] 1. A pipe base having a pedestal part on a part of its outer peripheral surface and having a mounting hole penetrating from the surface of the pedestal part to the inside, and a flange part having an outer diameter larger than the diameter of the mounting hole, and from the pedestal part. A sensor inserted into the mounting hole, a ring-shaped elastic sealing material interposed between the flange portion of the sensor and the pedestal portion, and injection molded on the surface of the pipe base so as to wrap the pedestal portion. A resin molded portion formed, and the elastic sealing material is sandwiched between the flange portion and the pedestal portion and sealed by injection pressure during molding of the resin molded portion and contraction stress after molding. Sensor mounting structure characterized by