JP2002162309A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent gel from extending into a bonding section in a pressure sensor in which a port is bonded on a case where the gel covers a pressure detecting section. SOLUTION: The gel 1 can be prevented from extending into the bonding section 2 by disposing a groove 8 with a V-shaped cross-sectional form on the case 6 and between the bonding section 2 and a recessed section 11, even in the case that the gel 1 is poured into the recessed section 11, and then the gel rises along a wall of the recessed section 11 and flows out from the recessed section 11. Accordingly, the adhesive quality between the case 6 and the port 5 is improved in the bonding section 2, and the airtight property for outside can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor, and more particularly to a structure for preventing a gel from sticking out.

[0002]

2. Description of the Related Art Conventionally, in a pressure sensor, a pressure detecting portion composed of a sensor chip and a glass pedestal is bonded to a concave portion of a case to protect the pressure detecting portion from contaminants and the like.
In some cases, a gel is injected into a concave portion of a case, and the pressure detecting section is completely covered with the gel.

Further, a port is formed so as to cover the pressure detecting portion for airtightness with the outside and pressure introduction, and the port is bonded to the case with an epoxy adhesive.

[0004]

However, in the conventional pressure sensor, in order to bond the case and the port, an adhesive portion for injecting an epoxy-based adhesive and a concave portion of the case for injecting the gel are close to each other. Because of the arrangement, when the gel is injected into the concave portion of the case, the gel may crawl up from the wall surface of the concave portion of the case, protrude from the concave portion of the case, and spread to the adhesive portion.

[0005] If the gel spreads to the bonding portion, there is a problem in that the adhesiveness of the bonding portion is deteriorated and the airtightness with the outside cannot be obtained.

In view of the above problems, it is an object of the present invention to provide a pressure sensor in which a port is bonded to a case in which a pressure detecting portion is covered by a gel, and the gel spreads to a bonding portion. Is to prevent it.

[0007]

According to a first aspect of the present invention, there is provided a pressure sensor having a step between an adhesive portion of a case portion and a concave portion.

By providing a step between the adhesive portion of the case portion and the concave portion, even if the protective member protrudes from the concave portion when the protective member is injected into the concave portion of the case portion, the step is formed on the protective member. Spreading can be stopped, and the protection member can be prevented from arriving at the bonding portion.

The pressure sensor according to the second aspect is characterized in that the step provided between the bonding portion and the concave portion is a groove.

By providing the groove between the bonding portion and the concave portion, even if the protective member protrudes from the concave portion of the case portion, the protective member can be stored in the groove, and the protective member arrives at the bonding portion. Can be prevented.

A third aspect of the present invention is characterized in that the groove has a V-shaped cross section.

Although the formation of the groove lowers the breaking strength of the groove, the V-shaped cross section has the effect of suppressing the lowering of the breaking strength.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

The pressure sensor according to the present embodiment is, for example,
It is used for detecting the pressure of intake air in an intake manifold in a vehicle engine.

FIG. 1 is a sectional view of a pressure sensor according to this embodiment. FIG. 2A shows a groove having a V-shaped cross section, and FIG. 2B shows a groove having a U-shaped cross section.

In this embodiment, as shown in FIG.
A rectangular pressure detector 3 having a function of converting the detected pressure into an electric signal by a predetermined function is formed.

The pressure detecting section 3 is formed by a sensor chip and a glass pedestal.

The pressure detecting section 3 is bonded to the recess 11 of the case 6 with a fluorosilicone adhesive.
It is connected to the connector pin 7 via the wire 4 to transmit an output obtained by converting the detected pressure into an electric signal to the outside.

Further, the pressure detecting section 3 is completely covered with the gel 1 injected into the concave portion 11 to protect the pressure detecting section 3 from contaminants such as water and carbon.

A port 5 is formed so as to cover the pressure detecting section 3 for airtightness and pressure conduction with the outside, and the port 5 is connected to the case 6 by an epoxy adhesive 10 injected into the bonding section 2. Glued.

Further, between the bonding portion 2 and the concave portion 11,
A groove 6 having a V-shaped cross section is provided in the case 6.

By providing the V-shaped groove 8 as described above, when the gel 1 is injected into the concave portion 11, the gel creeps up from the wall surface of the concave portion 11, Can be prevented from spreading to the bonding portion 2.

That is, as shown in FIG.
Since a certain amount of gel 1 can be stored in the V-shaped groove 8, the spread of the gel 1 can be prevented, and the spread of the gel 1 can be stopped by the edge portion 12 of the V-shaped groove 8. it can.

As described above, according to the present embodiment, by providing the V-shaped groove 8 between the bonding portion 2 and the concave portion 11, it is possible to prevent the gel 1 from spreading to the bonding portion 2. Thus, the adhesiveness between the case 6 and the port 5 in the adhesive portion 2 is improved, and airtightness with the outside can be ensured.

Hereinafter, the manufacturing process of the pressure sensor according to the present embodiment will be briefly described.

First, the pressure detecting section 3 is bonded to the case 6 provided with the concave portion 11 and the V-shaped groove 8, and the pressure detecting section 3 and the connector pin 7 are electrically connected by the wire 4.

Subsequently, the gel 1 is injected into the concave portion 11 provided in the case 6 in order to protect the pressure detecting section 3 from contaminants.

After this, the epoxy adhesive 1
By injecting 0 and bonding the port 5 and the case 6, the pressure sensor is completed.

The present invention is not limited to the above embodiment, but can be applied to various aspects.

For example, in the present embodiment, the cross-sectional shape of the groove provided between the bonding portion 2 and the concave portion 11 is V-shaped, but as shown in FIG. Even with the U-shaped groove 9, the gel 1 can be prevented from spreading to the bonding portion 2.

Further, by making the cross-sectional shape of the groove U-shaped, the gel 1 which has protruded can be removed from the V-shaped groove 8.
More can be stored.

However, by making the cross-sectional shape of the groove U-shaped, the portion shown by b in FIG. 2B becomes thinner and the breaking strength of the groove decreases, but the cross-sectional shape of the groove is reduced. With the V-shape, the portion indicated by a in FIG. 2B can be thickened, and a decrease in the breaking strength of the groove can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of a pressure sensor according to an embodiment.

2A is a diagram illustrating a V-shaped groove, and FIG. 2B is a diagram illustrating a U-shaped groove.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 1 ... Gel, 2 ... Adhesion part, 3 ... Pressure detection part, 4 ... Wire, 5 ... Port, 6 ... Case, 7 ... Connector pin, 8 ... V-shaped groove, 9 ... U-shaped groove, 10 ... Epoxy adhesive, 11 recess, 12 edge a, b ... thickness of groove

Claims (3)

[Claims] 1. A case having a recess, wherein a pressure detector is fixed to the recess, a protection member injected into the recess so as to cover the pressure detector, and provided around the case. A bonding portion, a port portion bonded to the case portion via the bonding portion so as to cover the pressure detection portion, and a step provided between the bonding portion and the concave portion. Pressure sensor. 2. The pressure sensor according to claim 1, wherein the step is a groove. 3. The pressure sensor according to claim 2, wherein the groove has a V-shaped cross section.