JP2536232Y2 - 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 sensor in which a semiconductor pressure sensor is directly fixed to a substrate on which an electric circuit is formed, and the substrate is held in a casing.

[0002]

2. Description of the Related Art A conventional pressure detector is shown in FIG.
The pressure detector 2 basically includes a box-shaped housing 6 closed by a cover member 4, a sensor casing 8 disposed in the housing 6, and a sensor casing 8.
The semiconductor pressure sensor 10 is housed in the housing 6 and a substrate 14 is fixed to the step of the housing 6 and is electrically connected to the semiconductor pressure sensor 10 via the lead frame 12.

A pressure introduction port 16 is provided at the bottom of the housing 6.
The pressure introducing part 18 in which is defined is protrudingly provided. At the bottom of the sensor casing 8, a pressure introducing cylinder 2 is provided.
The pressure introducing cylinder 20 is provided with a through hole 22 through which the semiconductor pressure sensor 10 receives the pressure fluid introduced from the pressure introducing port 16. An O-ring 24 is provided between the pressure introducing cylinder 20 and the pressure introducing section 18 for maintaining the airtightness in the housing 6.

[0004] A semiconductor pressure sensor 10 is fixed to a concave portion defined at a substantially central portion of the sensor casing 8, and a lead frame 12 is electrically connected to the semiconductor pressure sensor 10 via a wire 26. . By closing the sensor casing 8 with the cover member 28,
Dust is prevented from adhering to the semiconductor pressure sensor 10. One end of the lead frame 12
It is fixed to the substrate 14 by soldering 29. A circuit such as a comparator and a transistor (not shown) is provided on the substrate 14 for electrically processing the detected pressure.

As described above, in the pressure detector 2 according to the conventional example, the semiconductor pressure sensor 10 is housed in the sensor casing 8 and closed by the cover member 28, and the sensor casing 8 is moved together with the cover member 28. It has a double structure so as to be disposed in the housing 6.

[0006]

However, in the pressure detector 2 according to the conventional example, it is necessary to secure a space for mounting the sensor casing 8 in the housing 6 and, furthermore, because of the double structure, When the size of the housing 6 is reduced to reduce the size of the pressure detector 2, there is an inconvenience of being restricted. In addition, the structure itself is complicated and the number of parts is large, and soldering work is performed to electrically connect one end of the lead frame 12 to the board 14. There is a disadvantage that labor is required.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned disadvantages, and provides a pressure sensor suitable for miniaturization, cost reduction by simplifying the structure, and suitable for automatic production. The purpose is to:

[0008]

To SUMMARY OF THE INVENTION To achieve the above object, the present invention is, in a pressure detector for detecting the pressure of the introduced pressure fluid from the pressure inlet port, an upper housing and a lower
A casing consisting of a part housing, disposed within the casing, and having a hole for introducing a pressure fluid, and a substrate which an electrical circuit is formed directly on a predetermined position of the substrate
By being fixed, one end of the hole is airtightly closed.
The semiconductor pressure sensor is bulged formed opposite to each other physician with the inner wall surface of the upper housing and the lower housing, the upper housing and the lower the
By assembling the unit housing and the
A first holding portion and the second holding portion for holding by pressing the up and down direction, and a seal member provided on the contact portion between one of the substrate and the first holding portion or the second holding unit,
Formed on either the upper housing or the lower housing
A pressure introduction port having a pressure introduction port defined therein, and a communication portion between the pressure introduction portion and the substrate, the hole being provided between the pressure introduction portion and the substrate.
The pressure fluid introduced from the pressure introduction port is
Characterized Rukoto through hole is provided to guide the pressure sensor.

[0009]

The pressure detector according to the present invention basically includes a casing and a substrate disposed in the casing and having a semiconductor pressure sensor fixed thereto. Therefore, the substrate provided in the casing is held via the first and second holding portions which are formed so as to protrude from each other on the inner wall surface of the casing.

[0010] The pressure fluid introduced from the pressure introduction port is guided to the semiconductor pressure sensor through a hole defined in the substrate. In this case, the semiconductor pressure sensor is fixed so as to close one end of the hole defined in the substrate,
On the other hand, the contact portion between the substrate and the holding portion, which is the other end of the hole, is held airtight by a seal member. Therefore,
The pressure fluid introduced from the pressure introduction port is introduced into the semiconductor pressure sensor while maintaining airtightness.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing a pressure detector according to an embodiment of the present invention, and FIG. 2 is a central longitudinal sectional view of the pressure detector shown in FIG.

The pressure detector 30 basically includes a casing 36 in which an upper casing 32 and a lower casing 34 are integrally assembled, a board 38 positioned and held in the casing 36, A transparent cover member 40 mounted on the side surface of the casing 36.
The upper casing 32 and the lower casing 34 are integrally formed of a material such as resin.

A semicircular projection 44a for taking out lead wires 42a and 42b to be described later is provided on one side surface of the upper housing 32. A portion (not shown) provided on the inner wall surface of the lower housing 34 is engaged with the upper housing 32 and the lower housing 3 at a portion adjacent to the protrusion 44a.
4 are provided with a pair of claw members 46a and 46b. A step portion 48 for mounting the cover member 40 is defined on the side surface opposite to the side surface provided with the claw members 46a and 46b.

Further, on the inner wall surface of the upper housing 32,
When the upper housing 32 and the lower housing 34 are integrally assembled, the substrate 38 is pressed toward the lower housing 34 to
First and second wall portions 5 holding the inside of casing 36 in casing 36
0 and 52 (first holding units) are provided.

On the other hand, a projection 44b corresponding to the projection 44a of the upper housing 32 is provided on one side surface of the lower housing 34, and the projections 44a and 44b come into contact with each other and lead. A line hole 54 is defined. The protrusion 44b
A step 56 similar to that of the upper housing 32 is formed on the side surface opposite to the above, and the cover member 40 is attached to the steps 48 and 56 of the upper housing 32 and the lower housing 34.

On the inner wall surface of the lower housing 34, there is provided a block-shaped second member provided with pins 60 (one not shown) inserted into positioning holes 58a, 58b defined in the substrate 38. 1 support portion 62 (one is not shown), block-shaped second support portions 64a and 64b that contact the lower surface of the substrate 38 and support the substrate 38, and a rectangular shape provided substantially at the center. The third support portion 66 (second holding portion) is formed so as to protrude. The first to third support portions 62, 64a, 6
4b and 66 are the first and second wall portions 5 as described later.
Together with 0 and 52, it has a function of holding the substrate 38 in the casing 36. The second support portions 64a, 6
A substantially circular mounting hole 68a, 68b is formed in 4b. The third support portion 66 has a substantially circular concave portion 70.
Is defined, and an O-ring 72 (seal member) is mounted in the concave portion 70. At the center of the concave portion 70, a through hole 78 communicating with a port 76 (pressure introducing port) of a pressure introducing portion 74 formed so as to protrude outward from the bottom surface of the lower housing 34 is defined. I have.

Further, a pair of mounting holes 80a and 80b are formed in one side surface of the lower housing 34. The O-ring 72 is provided in the hole 8 defined in the substrate 38.
2 to hermetically maintain a contact portion between the upper surface of the third support portion 66 and the lower surface of the substrate 38. As a result, the pressure fluid introduced from the port 76 through the through hole 78 is guided to the semiconductor pressure sensor 84 through the hole 82 defined in the substrate 38 in a state where the pressure fluid is kept airtight.

A substrate 38 is provided between the upper housing 32 and the lower housing 34. In this case, the substrate 38 is positioned by inserting the pins 60 into the positioning holes 58a, 58b, and the substrate 38 is connected to the first to third support portions 62, 64a, 64b, 66 of the lower housing 34. It is held by the first and second walls 50 and 52 of the upper housing 32 and the bottom of the upper housing 32. On the substrate 38, for example, a semiconductor pressure sensor 84 is fixed via an adhesive or the like, and the semiconductor pressure sensor 84 is connected to a predetermined portion of an electric circuit (not shown) provided on the substrate 38 via a wire 86. Conducted. As described above, the pressure introducing section 74 is provided on the substrate 38.
The semiconductor pressure sensor 84 has a hole 82 defined therein for receiving the pressure fluid introduced from the port 76 of the semiconductor pressure sensor 84. The semiconductor pressure sensor 84 is fixed to the substrate 38 so as to seal the hole 82 from above. ing.

Further, on the substrate 38, a comparator 88, a pair of LEDs 90a and 90b, a resistor 92, a transistor 94, a lead wire pad 96 and the like are provided (see FIG. 2). The lead wire pads 96 are provided on both front and back surfaces of the substrate 38, and the lead wires 42a and 42b are connected to the respective lead wire pads 96. The connected lead wires 42a and 42b are connected to the casing 36.
Is taken out to the outside through a lead wire hole 54 defined on the side surface of the device, and connected to a device such as a controller (not shown).

The LED on the side of the casing 36 is
A cover member 40 made of a transparent material is attached so that the emitted lights 90a and 90b can be visually recognized. In this case, the cover member 40 includes the upper housing 32 and the lower housing 34.
The plurality of projections 98 formed on the steps 48 and 56 are integrally fitted to the casing 36 by fitting into the holes 100 of the cover member 40.

The pressure detector 30 according to the present embodiment is basically configured as described above. Next, the operation and effect of the pressure detector 30 will be described.

Here, an assembling operation in a factory or the like will be described. First, a substrate 38 is mounted between the upper casing 32 and the lower casing 34 which are integrally formed. In this case, as described above, the positioning holes 58 formed in the substrate 38 are formed.
a, 58b, the substrate 38 is inserted.
Is performed. The substrate 38 has a semiconductor pressure sensor 84, a comparator 88 and an LED 9 on it.
Circuit elements such as 0a and 90b are electrically connected in advance. Subsequently, the upper housing 32 and the lower housing 34 are
A pair of claw members 46a and 46b provided on the upper housing 32
Are engaged with a protrusion (not shown) formed on the lower housing 34 to integrally assemble them. After the assembly, the step 4 provided on the side surface of the casing 36
8 and 56, the cover member 40 is attached. At this time, the cover member 40 is easily attached to the casing 3 by fitting the projection 98 into the hole 100 defined in the cover member 40.
6 can be attached.

As described above, the pressure detector 3 according to this embodiment is
In the case of 0, unlike the related art, there is no need to perform a soldering operation for electrically connecting one end of the lead frame 12 to the substrate 14, and the assembly can be performed easily. Therefore, it is possible to reduce labor and cost by simplifying the work process.

Next, at the time of use, the pressure introducing portion 74 is fitted into a pipe of a fluid device (not shown) to make the fluid passage of the fluid device communicate with the port 76. The pressure fluid introduced from the port 76 is guided to the semiconductor pressure sensor 84 through the through hole 78, the concave portion 70, and the hole 82. In this case, the contact portion between the third support portion 66 in which the concave portion 70 is defined and the substrate 38 in which the hole portion 82 is defined is held airtight by an O-ring 72 made of an elastic body. Therefore, the pressure of the pressure fluid detected by the semiconductor pressure sensor 84 is converted into an electric signal, and the electric signal is
a and 42b to the external device.

As described above, the pressure detector 3 according to the present embodiment
0, the sensor casing 8 for accommodating the semiconductor pressure sensor 10 is not provided inside the housing 6 unlike the prior art, so it is necessary to secure a space for attaching the sensor casing 8 to the housing 6. There is no. Therefore, downsizing of the pressure detector 30 can be promoted. Further, even when the semiconductor pressure sensor 84 is directly fixed on the substrate 38, the connection portion between the substrate 38 and the third support 66 can be kept airtight by the O-ring 72.
As a result, since the pressure detector 30 can be manufactured with a simple structure, it is suitable for automatic production, and the productivity can be improved.

[0027]

According to the pressure sensor of the present invention, the following effects can be obtained.

Since it has a simple structure, the assembling work can be easily performed. That is, unlike the related art, it is not necessary to perform a soldering operation for electrically connecting one end of the lead frame to the substrate, and the operation process can be simplified, thereby reducing labor and cost. It becomes possible to plan.

Further, a hole for introducing a pressure fluid is defined in the substrate, and a semiconductor pressure sensor is fixed so as to close one end of the hole, while the other end of the hole is closed at the other end of the hole. A contact portion between a certain substrate and the holding portion can be held airtight by a seal member. Thus, since the pressure detector can be manufactured with a simple structure, it is suitable for automatic production, and it is possible to improve productivity.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a pressure detector according to an embodiment of the present invention.

FIG. 2 is a central longitudinal sectional view of the pressure detector shown in FIG.

FIG. 3 is a longitudinal sectional view of a pressure detector according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 30 ... Pressure detector 32 ... Upper case 34 ... Lower case 36 ... Casing 38 ... Substrate 40 ... Cover member 42a, 42b ... Lead wire 62 ... 1st support part 64a, 64b ... 2nd support part 66 ... 3rd support Part 72 ... O-ring 74 ... Pressure introduction part 76 ... Port 78 ... Through hole 82 ... Hole part 84 ... Semiconductor pressure sensor

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kiyoshi Nakaaki 364-1 Miyamoto, Ryuyo-cho, Iwata-gun, Shizuoka Prefecture Inside the Ryuyo Plant of Hamamatsu Optical Co., Ltd. (72) Toshiya Suzuki 364-1 Miyamoto, Ryuyo-cho, Iwata-gun, Shizuoka Prefecture Hamamatsu Photoelectric Inside Ryuyo Plant Co., Ltd. (72) Creator Koichi Omae 364-1 Miyamoto, Ryuyo-cho, Iwata-gun, Shizuoka Prefecture Inside Ryuyo Plant Co., Ltd. (72) Ryusuke Suzuki 364-1 Miyamoto, Ryuyo-cho, Iwata-gun, Shizuoka Hamamatsu Photovoltaic (72) Creator Hiroshi Furuta 364-1 Miyamoto, Ryuyo-cho, Iwata-gun, Shizuoka Prefecture Inside Ryuyo Factory (72) creator Masanori Kashiuchi 364-1, Miyamoto, Iwata-gun, Shizuoka Prefecture Hamamatsu Photoelectric Co., Ltd. Inside the Ryuyo Plant (56) References JP-A-2-132867 (JP, A) JP-A-5-223673 (JP, A) JP-A-5-223672 (JP, A) Open flat 3-46844 (JP, U) JitsuHiraku flat 2-21540 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A pressure detector for detecting a pressure of a pressure fluid introduced from a pressure introduction port, wherein the casing includes an upper housing and a lower housing, and is disposed in the casing to introduce the pressure fluid. Hole
And a substrate on which an electric circuit is formed, and by being directly fixed at a predetermined position on the substrate,
A semiconductor pressure sensor for closing one end portion of the hole hermetically, is bulged formed opposite to each other physician with the inner wall surface of the upper housing and the lower housing, integrally with the upper housing and the lower housing Assembled in
By kicking it, provided the substrate and the first holding portion and the second holding portion for holding by pressing the up and down direction, the contact portion between one of the substrate and the first holding portion or the second holding portion Formed on one of the upper housing and the lower housing.
A pressure introduction port in which a pressure introduction port is defined, and wherein the hole is provided between the pressure introduction section and the substrate.
The pressure fluid introduced from the pressure introduction port is communicated by half.
The pressure detector according to claim Rukoto through hole for guiding the conductor pressure sensor is provided.