JP2000337988A - Pressure detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the influence of stresses on the sensor element of a pressure detector which is constituted by caulking a housing made of a steel material to a connector case having a projecting section protruded from the main body section of the connector case in which the sensor element is arranged and made of a resin through the projecting section and, at the same time, to prevent the breakage of the connector case. SOLUTION: The main body section 31 of the connector case 3 of a pressure detector is formed in a columnar shape and the projecting section 33 of the case 33 is protruded from the outer peripheral side face 32 of the section 31 on one end side of the section 31. The projecting section 33 is inserted into an opening 74 provided on one end section of a housing 7 so as to close the opening 74 and the edge section 75 of the opening 74 is bent and caulked along the shape of the corner section formed of the front end face 35 and side face 34 of the projecting section 33. The connector case 3 is formed so that the angle θ1 between the outer peripheral side face 32 of the main body section 31 and the side face 34 of the projecting section 33 may become an obtuse angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure detecting device in which a second case is connected to a first resin case provided with a pressure detecting sensor element.

[0002]

2. Description of the Related Art At present, as a pressure detector of this kind,
A pressure sensor as shown in FIG. 3 as a schematic cross-sectional configuration has been put to practical use.
It is used in the range of MPa.

In this apparatus, a resin case (first case) J2 in which a signal extraction terminal J1 is insert-molded and a metal housing (second case) J3 are connected and integrally assembled. It has a configuration in which a sensor element J4 for pressure detection is housed and held in a case (first case) J2. The pressure introducing hole J32 of the housing J3 is a hole for introducing a high measuring pressure for applying to the sensor element J4 into the sensor.

Here, a resin case J2 and a housing J3
Is made by caulking. The resin case J2 includes a substantially columnar main body (sensor element disposing portion) J21 extending vertically in FIG. 3 and a protruding portion (connecting portion) J22 protruding from the outer peripheral side surface of the main body J21. Of the protrusion J22 is the side J2 of the protrusion J22.
It is bent and swaged so as to be locked at 3.

[0005]

By the way, in the conventional pressure detecting device (pressure sensor), the resin case J2 is pushed away from the housing J3 (upward in FIG. 3) by the measured pressure. At this time, stress is applied to the root J25 of the protruding portion J22 in the resin case J2.

In the resin case J2 of the pressure sensor, the angle θ1 formed between the outer peripheral side surface J24 of the main body J21 and the side surface J23 of the protruding portion J22 is a right angle as shown in FIG. Stress concentrates on J25.

The concentrated stress causes deformation near the base portion J25 of the resin case J2, and adversely affects the sensor characteristics of the sensor element J4 disposed on the resin case J2 side and located relatively near the base portion J25. May give. Further, in some cases, the concentrated stress may lead to destruction of the resin case J2 itself.

In particular, when the conventional pressure sensor is used for another purpose such as a brake oil pressure or a high-pressure fuel pressure, the detected pressure is used up to a higher pressure such as 0 to 20 MPa. The problem is more likely to occur.

The resin case J2 is connected as a connector to an external wiring member via the terminal J1, but when the sensor is removed from the external wiring member, stress is concentrated on the right-angled root portion J25. Occurs,
As a result, there is a possibility that the resin case J2 itself is destroyed or the sensor characteristics are adversely affected. Further, the same problem may occur when an impact is applied to the sensor, particularly the resin case J2, from the outside.

As described above, the second case is connected to at least the first case made of resin having the projecting portion projecting from one surface of the main body portion on which the sensor element is disposed, via the projecting portion. In the conventional pressure detecting device, the above problems due to stress concentration occur because the base of the protruding portion is perpendicular.

Accordingly, the present invention has been made in view of the above-described problems, and has been made in consideration of the above-described problem, and in a pressure detecting device, a first resin-made device having a sensor element disposed therein is provided.
It is an object of the present invention to suppress the above-mentioned problems from occurring by suppressing the concentration of stress on the base of the protruding portion in the above case.

[0012]

In order to make it difficult for stress to be concentrated at the root of the protruding portion in the first case, the second case is used.
It is conceivable to reduce the pressure receiving area of the first case that receives the measurement pressure introduced from the case side. For example,
In the conventional product shown in FIG. 3, the diameter of the main body J21 of the resin case J2 may be reduced. However, since the sensor element J4 and the terminal J1 are housed in the resin case J2, the diameter is reduced. Also have limitations.

[0013] Therefore, in the pressure detecting device, even if an attempt is made to increase the measured pressure, the usable pressure range is limited.

Therefore, the present inventors devised the configuration of the base of the protruding portion in the first case separately from reducing the pressure receiving area of the first case, so that stress concentration is less likely to occur. Focusing on obtaining, the present invention was created.

That is, according to the first aspect of the present invention, the main body (31) provided with the sensor element (1) for detecting pressure and the protruding portion (33) protruding from one surface (32) of the main body are formed. A pressure detecting device including a first case (3) made of resin and a second case (7) connected to the first case via at least the protruding portion. An angle (θ1) formed between the one side of the main body and the side surface (34) of the protruding portion extending in the protruding direction is an obtuse angle.

According to the present invention, the one surface (32) of the main body (31) of the first case (3) and the side surface (34) of the protruding portion (33) extending from the one surface of the main body in the protruding direction. Since the formed angle (θ1) is an obtuse angle, the base of the protruding portion in the first case can be made obtuse, and the concentration of stress on the base can be suppressed as compared with a conventional perpendicular configuration. be able to.

Further, the second case (7) is connected to the projection (3).
As a configuration for connecting to the first case (3) through the third case, a part (75) of the second case may be connected to the tip of the projecting portion in the projecting direction. Face (3
From 5) to the side surface (34), it can be bent and crimped along the shape of the corner formed by the tip end surface and the side surface.

According to the third aspect of the present invention, there is provided the second aspect.
The present invention provides a specific configuration of the first case (3), the second case (7), and the connection between the two cases (3, 7) in the pressure detection device of (1).

Here, in the case where the connection of the first and second cases (3, 7) is performed by caulking and fixing, as in the pressure detecting device of claim 2 and claim 3, the present inventor and the like. Searched for a suitable range of the bending angle (θ2) of the caulking. As a result, in consideration of the yield stress of the material used for normal caulking, as shown in FIG. 2, if the bending angle of the caulking is 103 ° to 133 °, the stress applied to the caulked portion is set to be equal to or less than the yield stress. It was found that it was possible and preferable (the invention of claim 4).

If the distance deviates from this range, the caulked portion of the second case (7) comes off before the root of the protruding portion (33) of the first case (3) breaks due to the above-mentioned stress concentration. Or be easily damaged. Also, as shown in FIG. 2, when the bending angle (θ2) of the caulking is 116 °,
The stress applied to the caulked portion is the smallest, which is preferable. However, such a tendency of concentration of the stress has a width due to the molding accuracy of the resin constituting the first case. Taking this width into account, a more preferable crimping bending angle (θ2)
Is 111 ° to 121 ° (the invention of claim 5).

Further, as described above, the angle (θ1) between the one surface (32) of the main body (31) and the side surface (34) of the protruding portion (33) is an obtuse angle. As in the sixth aspect, the bending angle (θ2) of the swaging according to the fourth or fifth aspect can be the same angle.

The second case (7) can be made of a steel material, and the first case (3) can be made of polyphenylene sulfide.

As described above, according to the present invention, in the first resin case in which the sensor element is provided, a very simple structure is adopted in which the angle (θ1), which was a right angle in the past, is made obtuse. In addition, it is possible to suppress the concentration of stress on the base of the protruding portion in the first case, thereby suppressing the influence of stress on the sensor element and preventing the case from being broken.

The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 is a cross-sectional view schematically showing an entire pressure detecting device (pressure sensor) 100 according to the first embodiment of the present invention. The pressure detecting device 100 is mounted on a vehicle, for example, and is applicable as a device that detects a brake hydraulic pressure or a high-pressure fuel pressure.

A pressure detecting sensor element (integrated sensor element) 1 for converting a pressure signal into an electric signal is anodically bonded to a glass pedestal 2 and a connector case (first case in the present invention) 3. Is fixed to a concave portion 30 formed on one end side with an adhesive such as silicon rubber.

The connector case 3 is made of resin (PP in this example).
S (polyphenylene sulfide) is formed by molding, and a connector pin 4 for outputting an electric signal is integrally formed and held therein by insert molding. The connector case 3 connects one end of the connector pin 4 to an external circuit (such as an ECU of a vehicle) via, for example, a wire harness (external wiring member) (not shown).
(Not shown), and the other end of the connector pin 4 is sealed in the recess 30 of the connector case 3 with an interface sealant 5 such as silicon rubber. I have.

In the recess 30 of the connector case 3, the sensor element 1 is connected to the other end of the connector pin 4 by a bonding wire 6 formed by wire bonding or the like.
And an electric signal from the sensor element 1 is transmitted from the bonding wire 6 to the external circuit via the connector pin 4.

Housing (second case in the present invention)
Reference numeral 7 denotes a pressure introducing hole 7 into which a measured pressure (detected pressure) is introduced.
2 and a main body 71 made of a steel material or the like (for example, carbon steel plated) having a screw portion 73 for fixing the device in place.

Further, the housing 7 includes a seal diaphragm 8 made of a thin metal (for example, SUS or the like) and a metal (for example, S).
A holding member (ring weld) 9 made of U.S.A. or the like is welded all around the main body 71 and hermetically joined to one end of the pressure introducing hole 72.

The connector case 3 and the housing 7 are connected and fixed by caulking, and a pressure detection chamber 10 is formed between the concave portion of the connector case 3 and the seal diaphragm 8 of the housing 7. The pressure detecting chamber 10 is filled with an oil 11 which is a pressure transmitting medium and a filling liquid, and forms a liquid sealing structure by the seal diaphragm 8 and the interface sealant 5.

Here, the connector case 3, the housing 7, and the connection configuration of these two members 3, 7 will be described in more detail.

As shown in FIG. 1, the connector case 3 has a substantially columnar main body 31 on which the sensor element 1 and the connector pin 4 are disposed, and one end side (recess 30) of the main body 31.
Side) (the side of the main body portion in the present invention) 32, and has a protruding portion 33 that protrudes over the entire circumference. The angle θ1 between the outer peripheral side surface 32 of the main body portion 31 and the side surface 34 of the protruding portion 33 extending in the protruding direction from the outer peripheral side surface 32 of the main body portion 31 is an obtuse angle larger than 90 °.

The housing 7 is connected to the connector case 3 (one end of the second case in the present invention).
Is provided with an opening 74, and the projecting portion 33 of the connector case 3 is inserted so as to close the opening 74. Here, the opening edge 75 of the opening 74 extends from the front end face 35 to the side face 34 in the projecting direction of the projecting section 33, and is formed on both sides 3.
It is bent and caulked along the shape of the corner formed by 4, 35.

The bending angle θ2 of the swaging is preferably from 103 ° to 133 ° as described later, and more preferably from 111 ° to 121 °.

In this embodiment, as shown in FIG.
The side surface 34 of the protruding portion 33 is linear from the root portion to the corner portion between the tip surface 35 and the angle θ1 and the bending angle θ2 are substantially the same.
The preferred range of 1 is also the same range as the bending angle θ2.

An O-ring 12 for hermetically sealing the pressure detection chamber 10 is provided around the outer periphery of the pressure detection chamber 10 formed between the concave portion 30 of the connector case 3 and the seal diaphragm 8 of the housing 7. The connector case 3 is housed and disposed in a groove (O-ring groove) 13 formed in a portion of the end face of the end surface of the connector case 3 which is located around the pressure detection chamber 10. The groove 13 has a ring shape having a shape corresponding to the outer peripheral shape of the O-ring 12. The O-ring 12 is housed in the groove 13, and the connector case 3 and the housing 7.
Are pressed by the holding member 9.

A method of manufacturing the pressure detecting device 100 having such a configuration will be described. First, the connector case 3 is molded using a thermoplastic resin such as PPS (polyphenylene sulfide) using a plurality of divided molds.

Next, the pedestal 2 and the sensor element 1 are disposed in the recess of the molded connector case 3, and the sensor element 1 and the connector pin 4 are connected by the bonding wire 6. To place. And
With the sensor element 1 side of the connector case 3 facing upward, a predetermined amount of oil 11 is injected from above the concave portion of the connector case 3 using a dispenser or the like.

Then, the housing 7 to which the seal diaphragm 8 has been welded all around is lowered so as to fit into the connector case 3 while keeping the housing horizontal from above.
And the pressing member 9 of the housing 7 is sufficiently contacted, and the opening edge 75 of the opening 74 of the housing 7 is fixed by caulking all around. Thus, the connector case 3 and the housing 7 are assembled, and the pressure detection chamber 10 sealed by the O-ring 12 is formed. Thus,
The pressure detection device 100 shown in FIG. 1 is completed.

The operation of the pressure detecting device 100 will be described. The device 100 is mounted, for example, by a threaded portion 73 of the housing 7 and an O-ring 14 attached to the threaded portion 73 so as to communicate with the inside of the brake oil piping system of the vehicle at an appropriate position. Then, the hydraulic pressure in the piping system is transmitted from the pressure introducing hole 72 of the housing 7 to the device 1.
Introduced within 00.

Then, this oil pressure is applied to the seal diaphragm 8.
Is transmitted to the sensor element 1 through the oil 11 in the pressure detection chamber 10. The sensor element 1 that has received the pressure (detected pressure) according to the oil pressure converts the pressure signal into an electric signal. This electric signal is transmitted from the sensor element 1 via the bonding wire 6 and the connector pin 4 to the external circuit (e.g., the ECU of the vehicle), and the brake oil pressure is detected.

According to the present embodiment, the angle θ1 between the outer peripheral side surface 32 of the main body 31 and the side surface 34 of the protruding portion 33 in the connector case (first case) 3 is an obtuse angle. Projection 33 at
Can be formed at an obtuse angle, and the concentration of stress on the root can be suppressed as compared with the conventional configuration of the root having a right angle.

In this embodiment, the housing (second
Of the housing 7 is connected to the connector case 3 via the protruding portion 33, the opening edge 75 of the opening 74, which is a part of the housing 7, extends from the distal end surface 35 of the protruding portion 33 to the side surface 34. Since it is bent and crimped along the shape of the corner formed by the two surfaces 34 and 35, a simple connection structure can be achieved without using a separate connection member.

In the present embodiment, a preferable range of the bending angle θ2 at the swaged portion is 103 ° to 103 °.
133 °, more preferably 111 ° to 121 °
Therefore, when the device is used (when pressure is applied) and when it is handled (detachment from an external wiring member, etc.), the stress concentrated on the housing 7 in the caulked portion can be made equal to or less than the yield stress of the housing 7.

Therefore, even if the sensor element 1 is arranged on the connector case 3 side as in the present embodiment and is located near the root of the protruding portion 33, adverse effects on the sensor characteristics can be avoided. Further, during use of the device, a relatively high pressure (for example, 20 MPa) can be applied without breaking the root itself of the protruding portion 33 and without causing the caulked portion to loosen or come off. Further, even when the connector case 3 is attached to and detached from the external wiring member (not shown) via the connector pins 4 or when an external impact is applied to the sensor, especially the connector case 3, the sensor characteristics are not changed. Adverse effects and connector case 3
Can be sufficiently avoided.

Here, the basis for determining the preferable range of the bending angle θ2 will be described with reference to FIG.
FIG. 2 shows the load (upward direction in FIG. 1) applied to the base of the protruding portion 33 in the connector case 3 when the present inventors introduce a measurement pressure or remove the connector case 3 from the external wiring member. 6 shows a simulation result by FEM when the operating pressure range of the apparatus 100 is set. In this simulation, the material of the connector case 3 is P
PS and the housing 7 are S10C as a steel material.

In FIG. 2, the horizontal axis represents the bending angle θ.
2 (unit: deg), but as described above, in the present embodiment, since the angle θ1 and the bending angle θ2 are substantially the same, the horizontal axis is also the value of the angle θ1.
The vertical axis indicates the stress (unit: MPa) applied to the caulked portion of the housing 7. The hatched line L1 shown in FIG. 2 is the yield stress of a normally used caulking material (S10C in this example).

As can be seen from FIG. 2, when the bending angle θ2 is 103 ° to 133 °, the yield stress can be made equal to or less than the yield stress L1, and detachment and breakage of the swaged portion can be prevented. When the bending angle θ2 of the caulking is 116 °, the stress applied to the caulking portion is the smallest. However, such a tendency of the concentration of stress has a width due to the molding accuracy of the resin forming the connector case 3 and the like. Considering this width, a more preferable bending angle θ2 is 1
11 ° to 121 °.

The tendency shown in FIG. 2 is that the resin connector case 3 having the protruding portion 33 protruding from the outer peripheral side surface 32 of the substantially columnar main body portion 31 in which the sensor element 1 is disposed. , A pressure detecting device 1 formed by caulking and fixing the housing 7 via the projection 33 (using the projection 33).
Assuming 00, this applies to the entire pressure detecting device 100.

(Other Embodiment) The connector case 3
The connection between the housing and the housing 7 via the protruding portion 33 may be performed by bonding using an adhesive or the like instead of caulking.
Further, the connector case 3 may be made of a resin other than PPS.

In short, according to the present invention, in the first case made of resin on which the sensor element is provided, the angle θ1 which has been a right angle in the related art is made obtuse so that the base of the protruding portion in the first case is formed. The main feature is to suppress the concentration of stress on the part, to suppress the influence of stress on the sensor element, and to prevent the case from being damaged. Needless to say, the design of the other components may be changed as appropriate.

[Brief description of the drawings]

FIG. 1 is an overall schematic sectional view of a pressure detecting device according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a bending angle θ2 and a stress in a caulked portion in the embodiment.

FIG. 3 is an overall schematic sectional view of a conventional pressure detecting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sensor element, 3 ... Connector case, 7 ... Housing, 30 ... Concave part of connector case, 31 ... Body part of connector case, 32 ... Outer side surface of body part, 33 ... Protrusion part of connector case, 34 ... Protrusion part Side surface, 35: Tip surface of projection, 74: Opening of housing, 75: Opening edge of opening, θ1: Angle between outer peripheral side of main body and side of projection, θ2: Bending angle of swaging.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F055 AA11 AA21 BB20 CC60 DD20 EE40 FF23 GG01 GG12 GG25 HH03 HH08 2F078 HA20

Claims (8)

[Claims] 1. A first resin case having a main body (31) provided with a sensor element (1) for detecting pressure and a protruding part (33) protruding from one surface (32) of the main body. (3) a pressure detecting device comprising: a second case (7) connected to the first case via at least the projecting portion; An angle (θ1) between the protrusion and the side surface (34) extending in the protrusion direction is an obtuse angle. 2. A part (75) of the second case (7).
Is a tip end face (3) in the projecting direction of the projection (33).
From 5) to the side surface (34), it is connected to the first case (3) by being bent and crimped along the shape of the corner formed by the tip surface and the side surface. The pressure detecting device according to claim 1, wherein: 3. In the first case (3), the main body (31) is substantially columnar, and the protruding portion (33) is provided at one end of the main body at an outer peripheral side surface (32) of the main body. )
The sensor element (1) is housed and fixed in a concave portion (30) formed on one end side of the main body, and is provided on one end side of the second case (7). Is provided with an opening (74), and the projection (33) is closed so as to close the opening.
Is inserted, and an opening edge (75) of the opening extends from the distal end surface (35) of the protrusion to the side surface (34) to form a corner formed by the distal end surface and the side surface. The pressure detecting device according to claim 2, wherein the pressure detecting device is bent and caulked along the shape. 4. The crimping bending angle (θ2) is 1
The pressure detection device according to claim 2, wherein the angle is from 03 ° to 133 °. 5. The bending angle (θ2) of the caulking is 1
The pressure detecting device according to claim 4, wherein the angle is 11 ° to 121 °. 6. The one surface (32) of the main body (31).
6. An angle (θ1) between the side surface (34) of the projection (33) and the projection (33) is substantially the same as the bending angle (θ2) of the caulking.
3. The pressure detecting device according to 1. 7. The pressure detecting device according to claim 1, wherein the second case is made of a steel material. 8. The pressure detecting device according to claim 1, wherein the first case is made of polyphenylene sulfide.