JP3509627B2 - Pressure detector - Google Patents

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 case made of resin in which a sensor element for detecting pressure is arranged.

[0002]

2. Description of the Related Art Currently, as a pressure detecting device of this kind,
A pressure sensor as shown in FIG. 3 as a schematic cross-sectional structure has been put into practical use, and the detected pressure is approximately 0 to 10 such as the pressure of air conditioner refrigerant for automobiles and power steering hydraulic pressure.
Used in the MPa range.

In this case, a resin case (first case) J2 in which a signal taking-out terminal J1 is insert-molded and a metal housing (second case) J3 are connected and assembled together, and a resin The case (first case) J2 has a structure in which a sensor element J4 for pressure detection is housed and held. Further, the pressure introduction hole J32 of the housing J3 is a hole for introducing a high measurement pressure to be applied to the sensor element J4 into the sensor.

Here, the resin case J2 and the housing J3
The connection is made by caulking. The resin case J2 includes a substantially columnar main body portion (sensor element disposition portion) J21 extending in the vertical direction in FIG. 3 and a protrusion portion (connection portion) J22 protruding from the outer peripheral side surface of the main body portion J21, and a housing J3. The end portion J31 of the side surface J2 of the protruding portion J22.
It is bent and crimped so as to be locked at 3.

[0005]

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

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

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

In particular, when the conventional pressure sensor is considered to be used for another application such as a brake oil pressure or a high fuel pressure, the detected pressure is used up to a higher pressure such as 0 to 20 MPa. Is more likely to occur.

Further, the resin case J2 is connected as a connector to an external wiring member via the terminal J1. When the sensor is detached from the external wiring member, stress concentration occurs at the right angle root portion J25. Occurs,
This may damage the resin case J2 itself or adversely affect the sensor characteristics. Further, the same problem may occur when an impact is applied to the sensor, especially the resin case J2, from the outside.

As described above, the second case is connected to at least the resin-made first case having the projecting part projecting from one surface of the main body part on which the sensor element is arranged, through the projecting part. In the pressure detecting device formed as described above, since the root portion of the protruding portion has a right angle, the above-mentioned problems due to stress concentration occur.

In view of the above problems, the present invention is directed to a pressure detection device, in which a first resin-made first sensor element is provided.
It is an object of the present invention to prevent the above-mentioned problems from occurring by suppressing the stress concentration on the root portion of the projecting portion in the case.

[0012]

[Means for Solving the Problems] In order to prevent stress from being concentrated on the root portion of the protrusion in the first case,
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 portion J21 of the resin case J2 may be reduced, but since the sensor element J4, the terminal J1 and the like are housed in the resin case J2, the diameter is reduced. There is also a limit.

Therefore, in the pressure detecting device, even if an attempt is made to increase the measurement pressure, the usable pressure range is limited.

Therefore, the inventors of the present invention have made it possible to prevent stress concentration from occurring by devising the root part structure of the protruding portion in the first case, in addition to reducing the pressure receiving area of the first case. Focusing on obtaining the present invention, the present invention has been created.

That is, according to the first aspect of the invention, the body portion (31) on which the sensor element (1) for pressure detection is arranged and the protrusion portion (33) protruding from one surface (32) of the body portion are provided. A first case (3) made of resin and a second case (7) connected to the first case through at least the protrusion, and from the second case side at the time of pressure measurement.
The first case causes the
In the pressure detection device that receives a pressure in the direction away from the case , the angle (θ) formed by one surface of the main body and the side surface (34) of the projection extending from the one surface of the main body in the projection direction.
The feature is that 1) is an obtuse angle.

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

Further, the second case (7) is provided with a protrusion (3
As a structure for connecting to the first case (3) via the third part (3), as in the invention according to claim 2, a part (75) of the second case is provided at the tip end in the projecting direction of the projecting portion. Surface (3
From 5) to the side surface (34), it can be bent and crimped along the shape of the corner formed by the tip surface and the side surface.

According to the invention described in claim 3, claim 2
In the pressure detecting device, the first case (3), the second case (7), and a specific configuration for connecting the both cases (3, 7) are provided.

Here, when the first and second cases (3, 7) are connected by caulking and fixing, as in the pressure detecting device according to the second and third aspects, the present inventors Searched for a suitable range of the bending angle (θ2) of this caulking. As a result, considering the yield stress of the material used for ordinary caulking, as shown in FIG. 2, if the bending angle of the caulking is 103 ° to 133 °, the stress applied to the caulking portion is equal to or less than the yield stress. It was found that it was possible and preferable (the inventions of claims 4 and 5 ).

If it deviates from this range, the caulked portion comes off in the second case (7) before the root portion itself of the protrusion (33) of the first case (3) is broken due to the above-mentioned stress concentration. It is also easy to be damaged. In addition, as shown in FIG. 2, when the crimping bending angle (θ2) is 116 °,
Although the stress applied to the caulked portion is the smallest and preferable, such a tendency of stress concentration has a width depending on the molding accuracy of the resin forming the first case and the like. Considering this width, a more preferable crimping bending angle (θ2)
Is 111 ° to 121 ° (the invention of claim 6 ).

Further, as described above, the angle (θ1) formed by the one surface (32) of the main body portion (31) and the side surface (34) of the protruding portion (33) is an obtuse angle. As in the invention described in Item 7, it is possible to set the same angle as the bending angle (θ2) of the caulking described in Claims 4 to 6 .

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 case made of resin in which the sensor element is arranged, a very simple structure in which the angle (θ1) which has been a right angle in the past is made an obtuse angle is adopted. It is possible to suppress the stress concentration on the root portion of the protruding portion in the first case, suppress the influence of the stress on the sensor element, and prevent the case from being broken.

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

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described. FIG. 1 is a sectional view showing an overall outline of a pressure detection device (pressure sensor) 100 according to the first embodiment of the present invention. The pressure detection device 100 is applicable, for example, as a device mounted on a vehicle to detect a brake hydraulic pressure or a high pressure fuel pressure.

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

The connector case 3 is made of resin (PP in this example).
It is made by S (polyphenylene sulfide) molding, and the connector pin 4 for outputting an electric signal is integrally molded and held therein by insert molding. The connector case 3 has one end of the connector pin 4 connected to an external circuit (e.g., ECU of a vehicle) via, for example, a wire harness (external wiring member) (not shown).
(Not shown) has a connecting portion 3a for electrical connection, 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. There is.

In the recess 30 of the connector case 3, the sensor element 1 is bonded to the other end side of the connector pin 4 by a bonding wire 6 formed by wire bonding or the like.
, And the 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 is a pressure introduction hole 7 through which the measured pressure (detection pressure) is introduced.
2 and a main body 71 made of a steel material (for example, carbon steel plated) having a screw portion 73 for fixing the device in place.

Further, the housing 7 includes a sealing diaphragm 8 made of a thin metal (for example, SUS) and a metal (for example, S).
A pressing member (ring weld) 9 made of US or the like is welded all around the main body portion 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 recess of the connector case 3 and the seal diaphragm 8 of the housing 7. The pressure detection chamber 10 is filled with oil 11, which is a pressure transmission medium and is a filled liquid, and the seal diaphragm 8 and the interface sealant 5 form a liquid-sealed structure.

Now, the connector case 3, the housing 7, and the connection structure 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 arranged, and one end side of the main body 31 (recess 30).
The outer peripheral side surface (one side of the main body portion in the present invention) 32 on the side) has a projecting portion 33 that projects over the entire circumference. The angle θ1 formed by the outer peripheral side surface 32 of the main body 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 31 is an obtuse angle larger than 90 °.

The connection side of the housing 7 with the connector case 3 (one end side of the second case in the present invention)
An opening 74 is provided in the opening, and the protruding portion 33 of the connector case 3 is inserted so as to close the opening 74. Here, the opening edge portion 75 of the opening portion 74 extends from the front end surface 35 to the side surface 34 in the projecting direction of the projecting portion 33 to the both sides 3
It is bent and crimped along the shape of the corners formed by 4 and 35.

The crimping bending angle θ2 is preferably 103 ° to 133 °, and more preferably 111 ° to 121 °, as described later.

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 with the tip end surface 35, and the angle θ1 and the bending angle θ2 are substantially the same, so the angle θ is the same.
The preferable range of 1 is also the same as the bending angle θ2.

An O-ring 12 for hermetically sealing the pressure detecting chamber 10 is provided around the outer periphery of the pressure detecting chamber 10 formed between the recess 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 portion (O-ring groove) 13 formed in a portion of the end surface of the connector case 3 located outside the pressure detection chamber 10. The groove portion 13 has a ring shape having a shape corresponding to the outer peripheral shape of the O-ring 12, and the O-ring 12 is housed in the groove portion 13, and the connector case 3 and the housing 7 are provided.
It is sandwiched by the pressing member 9 and is pressed.

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

Next, the pedestal 2 and the sensor element 1 are arranged in the recess of the molded connector case 3, the sensor element 1 and the connector pin 4 are connected by the bonding wire 6, and then the O-ring 12 is inserted into the groove portion 13. To place. And
With the sensor element 1 side of the connector case 3 facing upward, a certain 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 from above so that the housing 7 is fitted into the connector case 3 while keeping the same horizontal.
And the pressing member 9 of the housing 7 are sufficiently contacted, and the opening edge portion 75 of the opening portion 74 of the housing 7 is fixed by caulking the entire circumference. In this way, 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 mounted on the threaded portion 73 at a proper position of a brake oil piping system of a vehicle so as to communicate with the inside of the piping system. The hydraulic pressure in the piping system is supplied from the pressure introduction hole 72 of the housing 7 to the device 1
It is introduced in 00.

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

By the way, according to the present embodiment, the angle θ1 formed by 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. Protrusion 33 at
The root portion can be made obtuse, and stress concentration on the root portion can be suppressed as compared with the conventional configuration of the root portion having a right angle.

Further, in this embodiment, the housing (second
The case) 7 is connected to the connector case 3 via the protrusion 33, and the opening edge 75 of the opening 74, which is a part of the housing 7, extends from the tip surface 35 of the protrusion 33 to the side surface 34. Since they are bent and crimped along the shape of the corners formed by the both surfaces 34, 35, a simple connection configuration can be achieved without using a separate connecting member.

Further, in the present embodiment, the preferable range of the bending angle θ2 at the crimped portion is from 103 ° to
133 °, more preferably 111 ° to 121 °
Therefore, the stress concentrated on the housing 7 in the caulked portion can be set to be equal to or lower than the yield stress of the housing 7 when the device is used (when pressure is applied) and when it is handled (removal from the external wiring member).

Therefore, even if the sensor element 1 is arranged on the connector case 3 side and is located near the root of the projecting portion 33 as in this embodiment, it is possible to avoid adverse effects on the sensor characteristics. Further, during use of the device, a relatively high pressure (for example, 20 MPa) can be applied without destroying the root portion itself of the protrusion 33 and without causing loosening or disengagement of the caulked portion. Furthermore, even when the connector case 3 and the external wiring member (not shown) are attached / detached via the connector pin 4, and when the sensor, especially the connector case 3 is impacted from the outside, the sensor characteristic Adverse effects and connector case 3
The destruction of can be avoided sufficiently.

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 root of the projecting portion 33 in the connector case 3 when the present inventors introduce the measurement pressure or remove the connector case 3 from the external wiring member. 6 is a simulation result by FEM when the operating pressure range of the device 100 is set. The material used in this simulation is P for the connector case 3.
The PS and the housing 7 are S10C as a steel material.

In FIG. 2, the horizontal axis represents the bending angle θ.
Although it is 2 (unit: deg), 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 represents the stress (unit: MPa) applied to the crimped portion of the housing 7. The hatched line L1 shown in FIG. 2 is the yield stress of the caulking material (S10C in this example) that is normally used.

As can be seen from FIG. 2, when the bending angle θ2 is 103 ° to 133 °, the yield stress L1 or less can be achieved, and the caulked portion can be prevented from being detached or damaged. Further, when the bending angle θ2 of the caulking is 116 °, the stress applied to the caulking portion is the smallest, but such a tendency of stress concentration 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 crimping bending angle θ2 is 1
It is 11 ° to 121 °.

The tendency shown in FIG. 2 is compared with the resin-made connector case 3 having the protruding portion 33 protruding from the outer peripheral side surface 32 of the substantially columnar main body 31 in which the sensor element 1 is arranged. A pressure detecting device 1 in which the housing 7 is caulked and fixed via the protrusion 33 (using the protrusion 33).
If 00 is assumed, this can be said for the entire pressure detection device 100.

(Other Embodiments) The connector case 3
The connection between the housing 7 and the housing 7 via the protrusion 33 may be performed by joining using an adhesive or the like, instead of caulking.
The connector case 3 may be made of resin other than PPS.

In short, according to the present invention, in the first case made of resin in which the sensor element is arranged, the angle θ1 which has been a right angle in the past is made to be an obtuse angle so that the root of the protruding portion in the first case can be reduced. The main feature is to suppress the stress concentration on the part, to suppress the influence of the stress on the sensor element, and to prevent the case from being damaged. Of course, the other components may be appropriately designed and modified.

[Brief description of drawings]

FIG. 1 is an overall schematic cross-sectional view of a pressure detection 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 crimped portion in the above embodiment.

FIG. 3 is an overall schematic cross-sectional view of a conventional pressure detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sensor element, 3 ... Connector case, 7 ... Housing, 30 ... Connector case recessed part, 31 ... Connector case main body part, 32 ... Main body part outer peripheral side surface, 33 ... Connector case projected part, 34 ... Projected part Side surface, 35 ... Tip surface of protruding portion, 74 ... Housing opening portion, 75 ... Opening edge portion of opening portion, θ1 ... Angle formed by outer peripheral side surface of main body portion and side surface of protruding portion, θ2 ... Bending angle of caulking.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01L 19/06 G01L 9/04 G12B 17/08

Claims (9)

(57) [Claims] 1. A first case made of resin having a main body (31) on which a sensor element (1) for pressure detection is arranged and a protrusion (33) protruding from one surface (32) of the main body. (3) and a second case (7) connected to the first case via at least the protrusion ,
According to the measurement pressure introduced from the second case side,
Press the case 1 away from the second case.
In the received pressure detection device, the angle (θ1) formed by the one surface of the main body and the side surface (34) of the projection extending from the one surface of the main body in the projection direction is an obtuse angle. apparatus. 2. A part (75) of the second case (7).
Is the end surface (3) in the protruding direction of the protruding portion (33).
5) is connected to the first case (3) by being bent and crimped along the shape of the corner formed by the tip end surface and the side surface from the side surface (34) to the side surface (34). The pressure detecting device according to claim 1, wherein: 3. In the first case (3), the body portion (31) has a substantially columnar shape, and the protruding portion (33) is located at one end side of the body portion and has an outer peripheral side surface (32). )
The sensor element (1) is housed and fixed in a recess (30) formed on one end side of the main body portion, and is attached to one end side of the second case (7). Is provided with an opening (74), and the protrusion (33) is provided so as to close the opening.
Is inserted, and the opening edge portion (75) of the opening extends from the tip end surface (35) of the protrusion to the side surface (34), and a corner portion formed by the tip end surface and the side surface is formed. The pressure detection device according to claim 2, wherein the pressure detection device is bent along a shape and crimped. 4. The bending angle (θ2) of the caulking is 1
It is 03 to 133 degrees, The pressure detection apparatus of Claim 2 or 3 characterized by the above-mentioned. 5. A sensor element (1) for detecting pressure is provided by itself.
A body portion (31) disposed in the recess (30), and
It protrudes from one surface (32) of the main body and
The front end surface (35) and the front end surface and the one surface.
Tree with protrusions (33) including connecting sides (34)
A first case (3) made of oil and a part (7 ) from the tip end surface of the protrusion along the side surface.
Because 5) is bent and crimped,
Both were connected to the first case through the protrusion.
A second case (7) is provided, and the second case (7) is used for pressure measurement.
The first case is measured by the measurement pressure introduced from the case side.
The base is pressed in a direction away from the second case
In the pressure detection device, the one surface of the main body portion and the one surface of the main body portion are projected.
Angle with the side surface (34) of the protrusion extending in the direction
(Θ1) is an obtuse angle, and the bending angle of the caulking is also
The degree (θ2) is 103 ° to 133 °
Pressure detector. 6. The bending angle (θ2) of the caulking is 1
4. Further, characterized in that it is 11 ° to 121 °
Is a pressure detection device described in 5 . 7. The one surface (32) of the body portion (31)
Said protrusion (33) an angle (.theta.1) formed between the side surface (34) of, for 4 to claim, characterized in that it substantially a same angle as the bending angle of the swaging (.theta.2) and 6
The pressure detection device according to any one of 1 . Wherein said second casing (7) is a pressure detecting apparatus according to any one of claims 1 to 7, characterized in that consists of steel material. Wherein said first casing (3) is a pressure detecting apparatus according to any one of claims 1 <br/> to 8, characterized in that consists of polyphenylene sulfide.