JP2004037271A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized and pressure-resistant high pressure sensor in which a tapered surface of a connector is brought into contact with a tapered surface of the sensor, applying a load in the inserting direction between both the surfaces, and assembling the connector and the sensor. <P>SOLUTION: The pressure sensor 1 includes a connector housing 30 having a pressure receiving surface 32 which disposes a pressure sensitive element 20, and a sensor housing 40 having a recess 45 for inserting an inserting part 35 of the housing 30. A connector tapered surface 352 provided gradually becoming narrow along an inserting direction is formed on an outer peripheral surface of the inserting part 35 of the housing 30. A tapered surface 452 of the sensor gradually becomes narrow along the inserting direction is provided on an inner peripheral surface of the recess 4 of the housing 40. The housing 30 and the housing 40 are connected in a state that the tapered surface 352 of the connector is brought into close contact with the tapered surface 452 of the sensor. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
【Technical field】
The present invention relates to a pressure sensor that measures pressure using a pressure-sensitive element.
[0002]
[Prior art]
The pressure sensor is a sensor using a pressure-sensitive element having a strain gauge formed on a silicon substrate and a diaphragm for pressure detection formed by precisely etching the silicon substrate. The pressure sensor measures the pressure by measuring the amount of strain of the diaphragm caused by the pressure using the strain gauge.
[0003]
In a pressure sensor comprising a connector housing having a pressure-receiving surface on which a pressure-sensitive element is disposed and a sensor housing, the pressure-sensitive element is housed in a pressure chamber between the connector housing inserted into the sensor housing and the sensor housing. It is configured to:
[0004]
Since the pressure sensor is required to have durability and pressure resistance, after inserting the connector housing into the sensor housing, a part of the sensor housing is caulked and the two are firmly integrated. At the time of the caulking operation, it is necessary to provide a load receiving surface for contacting the sensor housing and the connector housing with each other and receiving a caulking load in the insertion direction.
[0005]
[Problem to be solved]
However, the conventional pressure sensor has the following problems.
That is, the load receiving surface for bringing the connector housing and the sensor housing into contact with each other needs to have a predetermined area or more according to a required caulking load. Therefore, the connector housing and the sensor housing have been increased in size, and the pressure sensor combining them has also been increased in size.
[0006]
The present invention has been made in view of such conventional problems, and has as its object to provide a compact pressure sensor.
[0007]
[Means for solving the problem]
The present invention provides a connector housing having a pressure-receiving surface on which a pressure-sensitive element is arranged, a sensor housing having a concave portion for inserting an insertion portion of the connector housing along a predetermined insertion direction, and a sensor housing having a concave portion inserted into the concave portion. A pressure sensor having a pressure chamber formed between a connector housing and the sensor housing, wherein the pressure chamber houses the pressure-sensitive element.
A connector taper surface is provided on an outer peripheral surface of the insertion portion of the connector housing so as to gradually decrease in diameter along the insertion direction.
A sensor taper surface is provided on an inner peripheral surface of the concave portion of the sensor housing so as to gradually decrease in diameter along the insertion direction.
The pressure sensor is characterized in that the connector housing and the sensor housing are joined with the connector taper surface and the sensor taper surface in close contact with each other (claim 1).
[0008]
In the pressure sensor according to the present invention, the connector housing is provided with the connector tapered surface, and the sensor housing is provided with the sensor tapered surface. When the connector housing and the sensor housing are joined to each other, the connector taper surface and the sensor taper surface are in close contact with each other.
And even when the area of the connector taper surface and the sensor taper surface is secured so as to obtain a sufficient contact area to receive a load acting between the connector housing and the sensor housing, these surfaces are The projected area in the insertion direction can be made smaller than the actual area due to the inclination of the connector taper surface and the sensor taper surface.
In this way, by making the projected area of the connector taper surface and the sensor taper surface smaller than the actual area, the cross-sectional area of the connector housing and the sensor housing orthogonal to the insertion direction can be suppressed, and the connector housing and the sensor The housing can be reduced in size. The pressure sensor of the present invention, which combines the connector housing and the sensor housing that have been miniaturized as described above, is small and excellent in size.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, the insertion portion of the connector housing includes a substantially cylindrical insertion base centered on an axis substantially parallel to the insertion direction, and a substantially cylindrical insertion tip having a smaller diameter than the insertion base. Wherein the connector taper surface is disposed between the insertion tip and the insertion base.
The concave portion of the sensor housing has a first concave portion that forms a substantially cylindrical inner peripheral surface capable of storing the insertion distal end portion, and a substantially cylindrical second concave portion that can be fitted to the insertion base portion. It is preferable that the sensor tapered surface is provided between the second concave portion and the first concave portion.
[0010]
In this case, the diameter of the insertion tip can be reduced by disposing the connector tapered surface between the insertion tip and the insertion base of the connector housing. Further, by using a connector housing having the insertion end portion having a reduced diameter, the entire pressure sensor can be further reduced in size.
[0011]
Further, an O-ring for sealing the pressure chamber is provided on an outer periphery of the insertion tip portion of the connector housing, and an O-ring is provided between the first recess and the second recess of the sensor housing. It is preferable that the sensor taper surface is configured to be used as an insertion guide surface for inserting the O-ring into the first recess of the sensor housing.
[0012]
In this case, there is no need to separately provide an insertion guide surface for inserting the O-ring into the first recess. Therefore, the diameter of the sensor housing can be further reduced, and the pressure sensor can be further reduced in size.
[0013]
It is preferable that an angle between the sensor taper surface and the connector taper surface and the insertion direction is 15 degrees to 35 degrees.
In this case, the load in the insertion direction can be efficiently borne by the contact between the sensor taper surface and the connector taper surface. Further, the O-ring can be inserted into the first recess along the sensor tapered surface. Therefore, the operation of inserting the O-ring becomes very smooth.
[0014]
On the other hand, if the angle is less than 15 degrees, the load in the insertion direction cannot be sufficiently borne between the sensor taper surface and the connector taper surface. If the angle exceeds 35 degrees, the O-ring cannot be inserted smoothly, and the O-ring may be damaged.
[0015]
Further, it is preferable that the sensor housing has a seal diaphragm, the pressure chamber is sealed by the seal diaphragm, and the pressure chamber is filled with a pressure transmitting medium ( Claim 5).
In this case, a seal diaphragm is provided on the bottom surface of the recess in the sensor housing. For this reason, it is difficult to adopt a structure in which the end face in the insertion direction of the insertion portion of the connector housing directly abuts on the bottom surface of the recess of the sensor housing.
Therefore, when the sensor housing has the seal diaphragm, the effect of the present invention is particularly effective.
[0016]
【Example】
(Example 1)
A pressure sensor 1 according to an embodiment of the present invention will be described with reference to FIG.
The pressure sensor 1 of the present embodiment has a connector housing 30 having a pressure receiving surface 32 on which the pressure-sensitive element 20 is arranged, and a sensor housing having a concave portion 45 for inserting the insertion portion 35 of the connector housing 30 along a predetermined insertion direction. 40. Further, a pressure chamber 42 is formed between the connector housing 30 inserted into the recess 45 and the sensor housing 40. The pressure chamber 42 accommodates the pressure-sensitive element 20.
[0017]
A connector taper surface 352 is provided on the outer peripheral surface of the insertion portion 35 of the connector housing 30 so as to gradually reduce the diameter in the insertion direction. A sensor taper surface 452 is provided on the inner peripheral surface of the concave portion 45 in the sensor housing 40 so as to gradually decrease in diameter along the insertion direction. The connector housing 30 and the sensor housing 40 are joined in a state where the connector taper surface 352 and the sensor taper surface 452 are in close contact with each other.
Hereinafter, this content will be described in detail.
[0018]
As shown in FIGS. 1 and 2, the pressure sensor 1 of this embodiment is a sensor assembled by inserting a connector housing 30 having a terminal pin 10 and a pressure-sensitive element 20 into a sensor housing 40 having a seal diaphragm 43. . That is, the pressure sensor 1 of the present embodiment has the pressure chamber 42 isolated from the fluid whose pressure is to be measured. The pressure sensor 1 is configured so that the pressure of the fluid acting on the seal diaphragm 43 can be detected by the pressure-sensitive element 20 via a pressure transmission medium sealed in the pressure chamber 42.
The pressure-sensitive element 20 is formed by processing a silicon layer on a silicon substrate to form a strain gauge and by precisely etching the silicon substrate to form a sensor diaphragm.
[0019]
The connector housing 30 is integrally formed of a PPS resin by inserting the terminal pins 10 as described later, and is electrically connected to an insertion portion 35 inserted into the sensor housing 40 and a connector (not shown) of an external device. And a socket part 300 for performing the operation.
[0020]
The insertion portion 35 of the connector housing 30 has a substantially cylindrical insertion base 353 centered on an axis substantially parallel to the insertion direction, and a substantially columnar insertion tip 351 smaller in diameter than the insertion base 353. are doing. A connector taper surface 352 is provided between the insertion tip 351 and the insertion base 353.
[0021]
Further, the insertion tip 351 is configured such that an O-ring 50 and a backup ring 51 for sealing the pressure chamber 42 can be disposed on the outer peripheral surface thereof. A ring groove 350 for disposing the ring 50 and the backup ring 51 is provided.
Note that the ring groove 350 of this example has an incomplete groove shape having no wall surface in the insertion direction, and is configured so as to be formed in combination with the inner surface of the sensor housing 40 as described later. is there.
[0022]
The socket section 300 is configured so that an external connector (not shown) for electrically connecting to an external device (not shown) can be inserted therein. One end of the pin 10 is projected. Each terminal pin 10 is configured to make electrical contact with each electrode of the external connector inserted into the socket 300.
[0023]
As shown in FIG. 1, the other end of the terminal pin 10 is exposed on the pressure receiving surface 32, which is the end face in the insertion direction of the connector housing 30, and the pressure-sensitive element 20 is arranged.
There are three terminal pins 10 for power supply, ground, and signal output. These terminal pins 10 are all inserted so that they penetrate the connector housing 30 from the socket portion 300 to the pressure receiving surface 32. It is integrally disposed in the connector housing 30 by molding.
[0024]
The boundary between each terminal pin 10 exposed on the pressure receiving surface 32 and the PPS resin is sealed by the sealing layer 12 made of a silicone-based sealing material, so that the pressure chamber 42 can be kept airtight.
Each terminal pin 10 is electrically connected to each other by a pressure-sensitive element 20 and a bonding wire 34 as shown in FIGS.
[0025]
The sensor housing 40 is made of stainless steel, and as shown in FIGS. 1 and 2, a concave portion 45 for inserting the insertion portion 35, and an insertion portion 35 in the concave portion 45 are provided on the connector housing 30 side of the seal diaphragm 43. It has a caulking portion 41 that engages with the insertion portion 35 in the inserted state.
[0026]
As shown in FIGS. 1 and 2, the concave portion 45 in the sensor housing 40 includes a first concave portion 451 that forms a substantially cylindrical inner peripheral surface into which the insertion tip 351 is inserted, and a substantially cylindrical shape into which the insertion base 353 is inserted. And a second concave portion 453 having a shape. A sensor tapered surface 452 is provided between the second concave portion 453 and the first concave portion 451.
[0027]
The sensor taper surface 452 has an angle R1 (see FIG. 2) with the insertion direction of 25 degrees so that the O-ring 50 provided at the insertion tip 351 of the connector housing 30 can be smoothly inserted into the first recess 451. It has been set.
In addition, a seal diaphragm 43 is provided on the bottom surface of the recess 45. As shown in FIG. 2, the seal diaphragm 43 is securely fixed to the sensor housing 40 by laser welding from the surface of the seal ring 431 laminated on the outer periphery thereof and providing a welded portion 435 reaching the sensor housing 40. ing.
[0028]
As shown in FIG. 1, the sensor housing 40 includes a pressure introduction hole 441 for introducing a fluid or gas as a pressure measurement target to the measurement environment 44 side of the seal diaphragm 43 toward the measurement environment 44 side, and a fluid as a pressure measurement target for the seal diaphragm 43 side. And a screw portion 442 for attaching the pressure sensor 1 to a pipe or the like for accommodating the like.
[0029]
In the pressure sensor 1 manufactured by assembling the connector housing 30 and the sensor housing 40 configured as described above, as shown in FIG. 1, the caulking portion 41 of the sensor housing 40 in which the connector housing 30 is inserted is deformed in the radial direction. It is. By deforming the caulking portion 41 in the inner diameter direction in this way, the caulking portion 41 is engaged with the insertion base 353 of the connector housing 30 and is fixed.
[0030]
The connector housing 30 and the sensor housing 40 have their connector tapered surfaces 352 and sensor tapered surfaces 452 in close contact with each other, thereby restricting the positions of the two in the insertion direction. The connector housing 30 and the sensor housing 40 are assembled in a state where a load in the insertion direction generated when the caulking portion 41 is caulked is applied between the connector taper surface 352 and the sensor taper surface 452. As shown in FIG. 2, the contact between the connector taper surface 352 and the sensor taper surface 452 prevents the distal end surface of the connector housing 30 and the bottom of the recess 45 of the sensor housing 40 from contacting each other. Are formed.
[0031]
The pressure sensor 1 has a pressure chamber 42 formed of a space formed by the pressure receiving surface 32 of the connector housing 30 and the seal diaphragm 43 of the sensor housing 40 facing each other. The pressure chamber 42 is filled with silicone oil as the pressure transmission medium. The O-ring 50 and the backup ring 51 are sealed in a gap between the ring groove 350 provided in the insertion tip 351 and the first recess 451. The O-ring 50 is held by the backup ring 51 pressed by the end face of the ring groove 350 opposite to the insertion direction, and is configured to withstand high pressure.
[0032]
When the pressure is measured using the pressure sensor 1 configured as described above, the pressure sensor 1 can be attached to a pipe or the like that stores a fluid or the like as a pressure measurement target by a screw portion 442 provided in the sensor housing 40. It is composed. Then, the pressure of the fluid as a pressure measurement target introduced to the seal diaphragm 43 side via the pressure introduction hole 441 is transmitted to the sensor diaphragm of the pressure-sensitive element 20 via the silicone oil filled in the pressure chamber 42. It is configured as follows.
[0033]
As described above, the pressure sensor 1 of the present embodiment is assembled with the connector taper surface 352 of the connector housing 30 and the sensor taper surface 452 of the sensor housing 40 in close contact with each other and a caulking load in the insertion direction of the connector housing 30 is applied. It is.
[0034]
Further, the connector taper surface 352 and the sensor taper surface 452 are arranged such that the angle R1 with respect to the insertion direction is 25 degrees. Therefore, it is possible to secure a sufficient contact area where the connector taper surface 352 and the sensor taper surface 452 come into contact with each other while suppressing the increase in the diameter of the connector housing 30 and the sensor housing 40, and to bear a sufficient load between the two. it can.
[0035]
As described above, the pressure sensor 1 assembled by bringing the connector taper surface 352 into contact with the sensor taper surface 452 with a sufficient contact area and applying a load in the insertion direction between the two is small and has high pressure resistance. It will be excellent.
[0036]
Further, when the connector housing 30 is inserted into the sensor housing 40, the O-ring 50 provided at the insertion tip 351 of the connector housing 30 is arranged such that the angle R1 with respect to the insertion direction becomes 25 degrees. The guide can be smoothly inserted by the provided sensor tapered surface 452. The pressure sensor 1 assembled as described above does not damage the O-ring 50 for sealing and can maintain its excellent performance for a long time.
[0037]
In addition, instead of the sensor housing 40 in the pressure sensor 1 of the present embodiment, a sensor housing having no seal diaphragm 43 can be applied. In this case, the fluid whose pressure is to be measured flows into the pressure chamber and acts directly on the sensor diaphragm of the pressure-sensitive element 20.
[0038]
(Example 2)
In this embodiment, as shown in FIG. 3, a connector housing 30 having an insertion portion 36 having a different structure from the first embodiment and a sensor housing 40 having a concave portion 46 having a different structure from the first embodiment are combined. It is an example of a sensor 1.
As shown in the figure, the insertion portion 36 of the connector housing 30 of the present example is formed in a columnar shape, and a connector tapered surface 362 is provided at a corner at the tip end in the insertion direction. A ring groove 360 for mounting the O-ring 50 is provided on an end surface of the insertion portion 36 in the insertion direction of the housing 30.
[0039]
As shown in the figure, the concave portion 46 of the sensor housing 40 is configured so that a columnar insertion portion 36 can be inserted therein, and a sensor taper configured to be able to come into contact with the connector tapered surface 362 at a bottom corner thereof. A surface 462 is provided.
[0040]
In the pressure sensor 1 of this example, the connector taper surface 362 and the sensor taper surface 462 are arranged so that an angle R2 between the connector and the insertion direction is 25 degrees. Therefore, a sufficient contact area where the connector tapered surface 362 and the sensor tapered surface 462 abut can be ensured without increasing the diameters of the connector housing 30 and the sensor housing 40.
Therefore, when assembling the connector housing 30 and the sensor housing 40, a caulking load in the insertion direction can be sufficiently applied to the contact surface where the connector taper surface 362 and the sensor taper surface 462 abut.
[0041]
The pressure sensor 1 manufactured by combining the connector housing 30 and the sensor housing 40 configured as described above is a small and highly pressure-resistant sensor.
The other configuration and operation and effect are the same as in the first embodiment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a structure of a pressure sensor according to a first embodiment.
FIG. 2 is an enlarged explanatory view showing the vicinity of a pressure chamber of a pressure sensor in the first embodiment.
FIG. 3 is a cross-sectional view illustrating a structure of a pressure sensor according to a second embodiment.
[Explanation of symbols]
1. . . Pressure sensor,
10. . . Terminal pin,
20. . . Pressure sensitive element,
30. . . Connector housing,
34. . . Bonding wire,
35. . . Insertion section,
36. . . Insertion section,
350. . . Ring groove,
351. . . Insertion tip,
352. . . Connector taper surface,
353. . . Insertion base,
363. . . Insertion base,
40. . . Sensor housing,
42. . . Pressure chamber,
45. . . Recess,
46. . . Recess,
451. . . First recess,
452. . . Sensor taper surface,
453. . . The second recess,
463. . . Main recess,

Claims (5)

A connector housing having a pressure-receiving surface on which a pressure-sensitive element is arranged, a sensor housing having a recess for inserting an insertion portion of the connector housing along a predetermined insertion direction, the connector housing inserted into the recess, and the connector housing A pressure chamber having a pressure chamber formed between the pressure sensor and the sensor housing, the pressure chamber containing the pressure-sensitive element.
A connector taper surface is provided on an outer peripheral surface of the insertion portion of the connector housing so as to gradually decrease in diameter along the insertion direction.
A sensor taper surface is provided on an inner peripheral surface of the concave portion of the sensor housing so as to gradually decrease in diameter along the insertion direction.
A pressure sensor, wherein the connector housing and the sensor housing are joined with the connector taper surface and the sensor taper surface in close contact with each other. 2. The connector according to claim 1, wherein the insertion portion of the connector housing has a substantially cylindrical insertion base centered on an axis substantially parallel to the insertion direction, and a substantially columnar insertion tip having a smaller diameter than the insertion base. Wherein the connector taper surface is disposed between the insertion tip and the insertion base.
The concave portion of the sensor housing has a first concave portion that forms a substantially cylindrical inner peripheral surface capable of storing the insertion distal end portion, and a substantially cylindrical second concave portion that can be fitted to the insertion base portion. A pressure sensor, wherein the sensor tapered surface is disposed between the second recess and the first recess. 3. The sensor housing according to claim 2, wherein an O-ring for sealing the pressure chamber is provided on an outer periphery of the insertion tip of the connector housing, and an O-ring is provided between the first recess and the second recess of the sensor housing. The pressure sensor according to claim 1, wherein the sensor taper surface between the two is used as an insertion guide surface for inserting the O-ring into the first recess of the sensor housing. 4. The pressure sensor according to claim 3, wherein an angle between the sensor taper surface and the connector taper surface and the insertion direction is 15 degrees to 35 degrees. The sensor housing according to any one of claims 1 to 4, wherein the sensor housing has a seal diaphragm, the pressure chamber is sealed by the seal diaphragm, and a pressure transmission is provided in the pressure chamber. A pressure sensor characterized by being filled with a medium.

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