JPH07151625A - Pressure sensor - Google Patents

Abstract

PURPOSE:To provide a high pressure sensor in which the reliability is ensured for a long term by protecting the internal component using an intermediate member at the time of assemblage thereby eliminating incomplete fitting. CONSTITUTION:In order to eliminate unstable state before a pressure sensor is inserted into a housing and secured in place, an intermediate member 12 is provided with an engaging piece 18 for snap shot and a pressure receiving member 7 is provided with an engaging hole 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor used by being attached to a container in which a high pressure fluid or gas is enclosed.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing a conventional pressure sensor of this type proposed by Japanese Patent Application No. 5-73323. In the figure, 1 is a pressure sensing element for converting the pressure of fluid or gas into an electric signal, 2 is a circuit part for amplifying the electric signal, 3 is a holder made of a plastic molding material for positioning and protecting the pressure sensing element 1, Reference numeral 4 denotes a substrate for fixing the pressure sensing element 1 and electrically connecting to the circuit portion 2, 5 denotes a spacer for providing a gap between the substrate 4 and the pressure sensing element 1, 6
Is an O-ring for sealing the fluid pressure, 7 is a cylindrical pressure receiving member for holding the pressure acting on the O-ring 6, 8 is a feedthrough capacitor for outputting an electric signal from the substrate 4 and reducing conductive electromagnetic noise, 9 Is a metal plate that supports the feedthrough capacitor 8, and 10 is a lead wire for outputting an electric signal to the outside through the connection terminal 11.

An intermediate member 12 receives the force of the pressure receiving member 7 and the metal plate 9 and positions and fixes the housing. The intermediate member 12 serves as a member for partitioning the portion where the pressure sensing means is provided and the other portion. It is fixed by crimping all around 13. Reference numeral 14 is a grommet for preventing water from entering from the outside, and 15 is a sealing resin used for fixing the grommet 14. Since both the grommet 14 and the intermediate member 12 are made of soft resin, the lower end outer peripheral edge 14a of the grommet 14 and the upper end inner peripheral edge 12a of the intermediate member 12 are bent together, so that the grommet 14 is moved.
Fit in. The housing 13 that constitutes the case of this pressure sensor has a screw 13a for attachment at the end and a pressure introduction hole 16 for guiding the fluid pressure to the pressure sensing element 1. In addition, terminal 1
1 is inserted in the resin component 17.

In the pressure sensor having the above structure, the pressure of the pressure medium filled in the pressure introducing hole 16 is taken out as an electric signal by the pressure sensing element 1.

[0005]

Since the conventional pressure sensor is constructed as described above, the pressure sensing element 1 and the circuit portion are provided inside the pressure receiving member 7 by using the holder 3 on the substrate 4 when assembling. 2, metal plate 9 and feedthrough capacitor 8
After encapsulating the parts up to the soldered state, the intermediate member 12 is installed as the next work so as to be in contact with the entire circumference of the end surface of the pressure receiving member 7. At this time, the pressure receiving member 7 and the intermediate member 12 are There is a first problem in that a step due to a dimensional error, that is, a gap is generated at a position where the pressure receiving member 7 and the intermediate member 12 are originally in contact with each other, resulting in incomplete fitting.

[0006] Further, the resin may infiltrate into the internal space of the pressure receiving member 7 while the sealing resin 15 is injected into the upper surface of the intermediate member 12 and cured. That is, when the surface roughness of each component is rough, the resin 15 penetrates into the internal space through the contact portion between the intermediate member 12 and the housing 13 and the contact portion between the pressure receiving member 7 and the intermediate member 12, for example. In addition, there is a second problem that waterproofness is not ensured due to an increase in internal pressure and an air path generated in the sealing resin 15 when the resin is thermally cured.

Further, when the lead wire 10 protected by the grommet 14 is connected to the connection terminal 11, the positioning becomes unstable and the lead wire holding strength is lowered, which is a third problem. That is, this is done by inserting the terminal 11 into the through hole of the cylindrical terminal 10a at the tip of the lead wire 10 and soldering it in order to connect the lead wire 10 to the connection terminal 11. At this time, the grommet 14 may move in the radial direction (the grommet 14 is not yet attached to the intermediate member 12 at this time), or the lead wire 10 may move along the longitudinal direction of the terminal 11, which makes the soldering work difficult. It was due to that.

The first aspect of the present invention has been made to solve the above-mentioned first problem. The intermediate member and the pressure receiving member are engaged with each other so as to be integrated with each other, thereby ensuring stable integration of the both members. A first object of the present invention is to obtain a pressure sensor that can be assembled and has reliability in assembly.

The invention of claim 2 is to solve the above-mentioned second problem, and by providing a sealing means between the housing and the intermediate member, the internal space of the sensor becomes airtight and high. A second object is to obtain a pressure sensor that is waterproof and reliable.

The invention of claim 3 is to solve the above-mentioned third problem, and a holding guide column is provided at the lead wire connecting portion of the intermediate member, and the lead wire is fixed thereto by a soft tube. In this way, a third object is to obtain a pressure sensor that can avoid instability of positioning when soldering the lead wire to the terminal and improve position stability.

[0011]

According to a first aspect of the present invention, there is provided a pressure sensor, wherein a pressure receiving member and an intermediate member are formed on an engaging piece formed on one of these members, and the other member thereof. It is integrated by the part that engages the joint piece.

In the pressure sensor according to the second aspect of the present invention, the sealing means for ensuring the airtightness inside the housing is provided between the housing and the intermediate member.

In the pressure sensor according to the invention of claim 3, a member for partitioning the housing into a portion where the pressure sensing means is provided and a portion other than this is provided in the housing, and a portion for connecting the terminal and the lead wire. Is provided in a portion other than the portion where the pressure sensing means is provided.

[0014]

According to the first aspect of the present invention, the intermediate member and the pressure receiving member are engaged with each other and integrated, so that stable integration of both can be obtained.

According to the second aspect of the invention, since the sealing means is provided between the housing and the intermediate member, the internal space of the sensor can be made airtight.

According to the third aspect of the present invention, since the holding guide column is provided on the intermediate member and the lead wire is fixed to the holding guide column by the soft tube, instability of the positioning when the lead wire is soldered to the terminal is avoided. it can.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 is a sectional view, FIG. 2 is a sectional view showing the intermediate member of FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIG.
5 is a side view seen from the right, and FIG. 5 is a cross-sectional view of a pressure receiving member in which the intermediate member of FIG. 4 is integrated.

In the figure, 18 is an engaging piece provided on the intermediate member 12, which is a claw for snap-fit engagement. 1
Reference numeral 9 denotes a locking hole provided in the pressure receiving member 7, which is separated from the upper end edge of the pressure receiving member 7 by the same length as the length from the lower end edge of the intermediate member 12 to the engaging piece 18 so that the engaging piece 18 is engaged. There is. Two
Reference numeral 0 is an O-ring, which keeps the housing 13 and the intermediate member 12 airtight. Reference numeral 21 denotes a holding guide column which is provided integrally with the intermediate member 12 and is provided inside the housing 13. Reference numeral 22 is an insertion hole for holding three lead wires provided in the holding guide column 21, and the lead wire 10 is connected to the terminal 11 through the insertion hole 22. 23 is a soft tube,
The lead wire 10 and the holding guide column 21 are covered.

As described above, when the engaging piece 18 of the intermediate member 12 and the locking hole 19 of the pressure receiving member 7 are engaged and integrated as shown in FIG. 5, for example, between the intermediate member 12 and the pressure receiving member 7. Even if there is a step due to a dimensional error, stable integration of both can be achieved.

Further, when the O-ring 20 is provided between the housing 13 and the intermediate member 12, the internal space of the sensor has an airtight structure, so that the resin does not enter and the waterproof property is secured.

Further, the lead wire 1 is obtained by inserting the holding guide column 21 into the soft tube 23 above the intermediate member 12.
0 through the lead wire holding through hole 22
When 0 is passed and then a part of it is soldered to the terminal 11 insert-molded in the intermediate member 12, instability of positioning at the time of soldering can be avoided, and position stability is improved. Moreover, by bringing the connecting portion between the lead wire 10 and the terminal 11 to the upper side of the intermediate member 12 and eliminating the grommet, the intermediate member 12 can completely separate the inner and outer spaces and contribute to ensuring waterproofness.

[0022]

According to the first aspect of the present invention, since the intermediate member and the pressure receiving member can be engaged and integrated with each other, stable integration of both can be achieved, and reliability of assembly can be obtained. Is obtained.

According to the second aspect of the present invention, since the sealing means is provided between the housing and the intermediate member, the second effect is obtained in which the internal space of the sensor has an airtight structure and high waterproof reliability is obtained.

According to the third aspect of the present invention, since the holding guide column is provided at the lead wire connecting portion of the intermediate member and the lead wire is fixed to this by the soft tube, the positioning of the lead wire at the time of soldering to the terminal is performed. The third effect is that instability can be avoided and positional stability can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a pressure sensor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the intermediate member of FIG.

3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a side view of FIG. 2 as viewed from the right.

5 is a cross-sectional view of a pressure receiving member that integrates the intermediate member of FIG.

FIG. 6 is a sectional view showing a conventional pressure sensor.

[Explanation of symbols] 1 pressure sensing element 2 circuit part 3 holder 4 substrate 5 spacer 7 pressure receiving member 8 through capacitor 9 metal plate 10 lead wire 11 terminal 12 intermediate member 13 housing 15 sealing resin 16 pressure introducing hole 18 engaging piece 19 Locking hole 20 O-ring 21 Holding guide column 22 Insertion hole 23 Soft tube

Claims (4)

[Claims] 1. A pressure sensor used in the vicinity of a pressure medium for use, comprising: a housing; and a pressure medium introduced through a pressure introduction hole provided in the housing to sense the pressure of the pressure medium, and an electric signal of the pressure signal. A pressure sensing means having a pressure sensitive element for converting to a pressure sensing member, a pressure receiving member provided in the housing for receiving pressure applied to other than the pressure sensing means, and an intermediate member for fixing the pressure receiving member at a predetermined position in the housing. In the pressure sensor having, the pressure receiving member and the intermediate member are integrated by an engaging piece formed on one of these members and a portion formed on the other member and engaging with the engaging piece. A pressure sensor characterized in that. 2. A pressure sensor mounted near a pressure medium to be used, wherein the pressure of the pressure medium introduced from a housing and a pressure introducing hole provided in the housing is sensed to generate an electric signal. A pressure sensing means having a pressure sensitive element for converting to a pressure sensing member, a pressure receiving member provided in the housing for receiving pressure applied to other than the pressure sensing means, and an intermediate member for fixing the pressure receiving member at a predetermined position in the housing. In the pressure sensor having the above-mentioned, the pressure sensor is provided between the housing and the intermediate member, and sealing means is provided for ensuring airtightness in the housing. 3. A pressure sensor mounted near a pressure medium for use, comprising: a housing; and the pressure of the pressure medium introduced from a pressure introduction hole provided in the housing to sense an electric signal. In a pressure sensor having a pressure sensing means having a pressure-sensitive element for converting to, and a lead wire sending out the electric signal to the outside through a terminal communicating with the pressure sensing means, the housing is provided with the pressure sensing means. And a member for partitioning the other portion into a portion provided inside the housing, and a portion for connecting the terminal and the lead wire is provided at a portion other than the portion where the pressure sensing means is provided. And pressure sensor. 4. A holding guide column is provided in a member for partitioning the inside of the housing, the lead wire is inserted into the soft tube together with the holding guide column, and the lead wire is passed through a lead wire holding insertion hole provided in the member. 4. The pressure sensor according to claim 3, wherein the pressure sensor is connected to a terminal, and at least the connecting portion between the terminal and the lead wire and the soft tube are fixed by a resin filled outside the housing of the member.