JPH10221194A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve economical efficiency in manufacture, durability and operation reliability, and realize miniaturization, by using structure wherein a pressure sensor element is fixed and maintained without using fixing screws, and structure wherein assembling stress is not applied to a circuit board. SOLUTION: A pressure sensor element 21 is fitted and held in a sensor accommodating case 30. The elastic pressing force of an elastic spring 42 which acts by fitting a stem 31 is applied to the element 21. A flange part 23 is pressed and positioned in a sensor engaging step part of the case 30. Thereby use of fixing screws can be omitted, so that the number of components is reduced, a fixing screwing process is omitted, and manufacturing profitability is improved. A space for forming screw holes or the like is made unnecessary, the case 30 and the outer diameter of the stem 31 can be designed to be small, and miniaturization is possible. The thickness direction of a circuit board 27 is positioned in the case 30, in the floating state by a gap (a), so that stress is not applied to solder 41 or the like connected with a connection terminal 32 or the like. Thereby reliability and durability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor used for detecting the pressure of a pressure fluid, and in particular, to dispense with an assembling screw for mounting the pressure sensor used when assembling the pressure sensor. The present invention relates to a pressure sensor having a structure capable of improving assembling workability and economy, and at the same time, enabling downsizing.

[0002]

2. Description of the Related Art As a conventional pressure sensor having a built-in semiconductor pressure detecting element, for example, there is one having a structure as shown in FIG. Hereinafter, a schematic configuration of this conventional example will be described.

[0003] Reference numeral 1 denotes a pressure sensor element, and a flange 1A of the pressure sensor element 1 is sandwiched between a sensor fitting member 2 and a sensor holder 3. Reference numeral 4 denotes a stem having a pressure introduction port 5 at the center, and the sensor holder 3 is fitted and held on the stem 4. And at this time,
Pressure introduction pipe 1B provided in pressure sensor element 1
Is a pressure inlet 5 provided at the center of the stem 4.
The O-ring 6 and the seal ring 7 are attached to the pressure introducing pipe 1B to fill the gap between the pressure introducing pipe 1B and the pressure introducing hole 5 at the time of fitting. The space between 1B and the pressure introducing hole 5 is sealed. A circuit board 8 is placed on the upper surface of the sensor fitting member 2, and the circuit board 8 is sandwiched between the sensor fitting member 2 by a pressing member 9. Reference numeral 10 denotes a case fixed by a caulking means to a flange portion 13 formed on the upper opening edge of the stem 4. The case 10 has a connector portion 12 in which a connection terminal 11 is inserted.
Are integrally formed. 14 is the pressure sensor element 1
Lead pins 15 drawn out of the circuit board 8
A conductive spring 16 for electrically connecting the circuit of the circuit board 8 and the connection terminal 11; and 17 a joint fastening of the sensor fitting member 2, the sensor holder 3 and the stem 4 The fixing screw to be used is shown.

[0004] Next, the procedure for assembling the pressure sensor will be described. First, an O-ring 6 and a seal ring 7 are mounted in the pressure introducing hole 5 of the stem 4.
The sensor holder 3 is fitted. After a while, sensor holder 3
After inserting the pressure introducing pipe 1B of the pressure sensor element 1 from above into the pressure introducing hole 5, the sensor fitting member 2 is fitted from above the sensor holder 3 toward the pressure sensor element 1.

Next, the sensor fitting member 2, the sensor holder 3, and the stem 4 are fastened together using the fixing screw 17, and the flange 1 A of the pressure sensor element 1 is clamped and fixed between the sensor fitting member 2 and the sensor holder 3.

The fixing screw 17 used at this time is screwed at a plurality of positions (3 to 4 positions) in the circumferential direction of the sensor fitting member 2. Next, the conductive spring 14 is inserted from above the sensor fitting member 2 toward the lead pin 15, and further, the circuit board 8, the holding member 9, the conductive spring 16, and the case 10 are engaged in this order. A pressure sensor is configured by caulking the lower opening edge of the flange 10 to a flange 13 provided on the stem 4.

[0007]

In the conventional pressure sensor constructed as described above, a plurality of fixing means are used as fixing means for fixing the pressure sensor element 1 during the assembling process. Since each of the sensor fitting member 2, the sensor holder 3, and the stem 4 is jointly fastened using the screw 17, a plurality of screw parts are required, and the screw fastening operation ( ), The cost is increased due to the increase in the number of parts and the number of assembling steps, and the productivity is also impaired.

Further, a space for forming a screw hole for screwing the plurality of fixing screws 17 and a thickness of a stem are required, and a head of the fixing screw 17 having a larger diameter than the screw hole is disposed. Such a configuration is disadvantageous when a small pressure sensor is required because the entire shape of the pressure sensor becomes large because a space for the pressure sensor is required. Further, the conductive springs 14 and 16 for electrically connecting the connection terminals 11 and the lead pins 15 are merely elastic pressure contacts with the circuit of the circuit board 8, so that a contact failure may occur due to the influence of vibration or the like. There was also a problem that the substrate was damaged and durability and connection reliability were lacking.

The present invention has been made in view of the above, and has a structure in which the pressure sensor element can be fixedly maintained without using a fixing screw, thereby reducing the number of parts and the number of assembling steps. It is a first object of the present invention to provide a pressure sensor capable of reducing the cost and size of the pressure sensor.

Further, according to the present invention, the circuit board (printed circuit board) mounted inside the pressure sensor has a circuit board mounting structure in which no mounting stress is applied, thereby effectively preventing damage to the circuit board. It is a second object of the present invention to provide a pressure sensor capable of improving contact reliability and operation reliability.

[0011]

In order to achieve the first object, according to the first aspect of the present invention, a sensor locking step is formed at a connector portion into which a connection terminal is inserted and at a periphery of an opening. A sensor housing case forming a sensor housing recess, a pressure sensor element having a flange and a pressure introducing pipe engaged with the sensor locking step, and inserted through a sleeve around the outer periphery of the pressure introducing pipe. A circuit board having a circuit supported and soldered to the lead pins and the connection terminals expended from the pressure sensor element;
A stem having a pressure introduction port into which the pressure introduction pipe is inserted and tightly fitted on the outer peripheral surface of the sensor storage case; and a stem housed in the pressure introduction port, the stem being tightly attached to the sensor storage case. When fitted, the pressure sensor has a pressure positioning means for positioning the pressure sensor element by resiliently pressing the flange provided on the pressure sensor element against the sensor locking step. And

According to another aspect of the present invention, there is provided a pressure sensor in which a thickness direction of a circuit board soldered to lead pins and connection terminals is floated in a sensor storage case. It is characterized by:

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings.

FIG. 1 is a sectional view of the pressure sensor according to the present embodiment. The components required for assembling the pressure sensor will be described with reference to FIGS. Reference numeral 21 denotes a semiconductor type pressure sensor element.
The outer case 22 has a flange 23 and a pressure introducing pipe 24.
Is protruding. Reference numeral 25 denotes a plurality of lead pins expended from the pressure sensor element 21.

Reference numeral 26 denotes a sleeve fitted on the outer periphery of the pressure introducing pipe 24, and 27 denotes a circuit board on which a predetermined circuit pattern, a noise filter and the like are mounted.
The circuit board 27 is provided with through holes 28 and 29 penetrating the sleeve 26 and the lead pins 25.

Next, referring to FIG.
The configuration of the stem 31 will be described. The sensor storage case 30 is a resin cylindrical body formed by insert-molding the connection terminal 32.
Sensor housing recess 3 into which pressure sensor element 21 is fitted.
3, a connector part 34 for fitting a mating connector (not shown), and a stem caulking part 35 are formed. 4
Reference numeral 0 denotes a sensor locking step formed at the opening edge of the sensor housing 33. The stem 31 has, in its central axial direction, a pressure inlet 36 having an inner diameter to which the outer peripheral surface of the sleeve 26 is closely fitted, a case fitting recess 37 for fitting the sensor storage case 30, and a case fitting recess 37. A crimping edge 38 is formed around the opening.

The above is the embodiment showing the components of the pressure sensor. Next, the procedure for assembling the pressure sensor using the above components will be described.

First, a sleeve 26 is inserted into the pressure introducing pipe 24 of the pressure sensor element 21, and then the sleeve 26 is inserted from below into a through hole 29 provided in the circuit board 27.
And the lead pin 25 of the pressure sensor element 21
Into the through hole 28 provided in the circuit board 27,
The circuit board 27 is mounted on the pressure sensor element 21, and the lead pins 25 and the circuit pattern of the circuit board 27 are connected by soldering 39 (see FIG. 3).

Next, the outer case part 2 of the pressure sensor element 21 thus assembled with the sleeve 26 and the circuit board 27 is assembled.
2 is fitted into the sensor storage recess 33 of the sensor storage case 30. At this time, the flange 23 provided on the pressure sensor element 21 as shown in FIG.
0, and then the connection terminal 32, which is insert-molded in the sensor housing case 30, and the circuit of the circuit board 27 are connected by soldering 41. The O-ring 44 is mounted on the pipe 24.

Next, the stem 31 is inserted into the case fitting recess 3.
7 is held so that the caulking edge 38 faces upward, and the elastic pressure spring 42 and the seal ring 43 are dropped into the pressure inlet 36 of the stem 31 in this order. Then, the sensor housing case 30 in which the pressure sensor element 21 and the circuit board 27 are already assembled is placed in the case fitting recess 37 of the stem 31.
Are fitted from above.

At this time, the lower end of the pressure introducing pipe 24 of the pressure sensor element 21 is
In order to receive the elastic pressure of 2, the pressure sensor element 21 is pushed up by the elastic pressure of the elastic pressure spring 42, and the flange 23 of the pressure sensor element 21 is locked and positioned by the sensor locking step 40. Therefore, a caulking edge 38 provided on the stem 31 is provided.
Is crimped so as to enter the stem crimping portion 35 provided in the sensor storage case 30, so that the sensor storage case 30 and the stem 31 are integrally joined, and the pressure sensor is assembled and completed. . At this time, the upper and lower surfaces of the peripheral portion of the circuit board 27 located in the sensor storage case 30 have a gap between the sensor storage case 30 and the upper surface of the circuit board 27 so as not to come into contact with the sensor storage case 30. (A).

As described above, according to the pressure sensor having the above-described structure, the sensor housing case 30 is assembled when the pressure sensor is assembled.
The pressure sensor element 21 fitted and held in the pressure sensor element 21 applies an elastic pressure pressing force of an elastic pressure spring 42 acting by fitting the stem 31 into the sensor storage case 30 to the pressure sensor element 21. 21 collar 23
Are pressed and positioned in the sensor locking step portion 40 of the sensor storage case 30.

As described above, the pressure sensor element 21 located in the sensor storage case 30 can be positioned in the sensor storage case 30 by receiving the elastic pressing force of the elastic pressure spring 42, so that it is used in the conventional example. This eliminates the use of the fixing screw 17, thereby reducing the number of parts and the step of screwing the fixing screw 17, thereby improving the economics of manufacturing the pressure sensor.

Further, since the fixing screw 17 is not used, it is not necessary to secure a space for providing a screw hole or the like into which the fixing screw 17 is to be screwed, so that the outer diameters of the sensor storage case 30 and the stem 31 are reduced. The pressure sensor can be designed to be small, so that a compact pressure sensor can be obtained.

The pressure sensor element 21 positioned in the sensor storage case 30 is pressed by a spring force of a resilient spring 42, and the spring force is applied to the force (vibration of the pressure sensor element and the circuit board). By setting the pressure sensor element 21 larger than (product of mass and vibration acceleration), the pressure sensor element 21 does not vibrate when the pressure sensor vibrates, and the pressure sensor element 21 is effectively positioned.

In the thickness direction of the circuit board 27 located in the sensor storage case 30, the circuit board 27 does not come into contact with the wall surface or the like of the sensor storage case 30 due to the gap (a) and floats in the sensor storage case 30. In this state, no stress is applied to the circuit board 27. Therefore, no stress is applied to the soldering 39, 41 connected to the lead pin 25 and the connection terminal 32, and the connection is prevented. Reliability and durability are improved.

In the above-described embodiment, the elastic pressure spring 42 is used as the pressing and positioning means for the pressure sensor element 21. However, the present invention is not limited to this elastic pressure spring 42. For example, a rubber-like elastic body may be used. You may.

[0028]

As described above, according to the present invention, the manufacturing cost, durability and operation reliability of a pressure sensor having a built-in pressure sensor element 21 can be improved, and the pressure sensor can be downsized. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure sensor according to the present invention.

FIG. 2 is an exploded view of a pressure sensor element 21, a sleeve 26, and a circuit board 27 assembled in the pressure sensor according to the present invention.

FIG. 3 is an assembly view of the member shown in FIG. 2;

FIG. 4 is a sectional view of a sensor housing case 30 and a stem 31 which are constituent members of a pressure sensor according to the present invention.

FIG. 5 is a sectional view of a pressure sensor according to the present invention before a stem 31 is attached to a sensor storage case 30;

FIG. 6 is a sectional view of a conventional pressure sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 ... Pressure sensor element 22 ... Outer case 23 ... Flange part 24 ... Pressure introduction pipe 25 ... Lead pin 26 ... Sleeve 27 ... Circuit board 28 ... Through hole 29 ... Through hole 30 ... Sensor storage case 31 ... Stem 32 ... Connection terminal 33 ... Sensor housing concave part 34 ... Connector part 35 ... Stem caulking part 36 ... Pressure inlet 37 ... Case fitting concave part 38 ... Caulking part 39 ... Soldering 40 ... Sensor locking step part 41 ... Soldering 42 ... Elastic pressure spring 43 ... Seal Ring 44 ... O-ring 45 ... O-ring

Claims (2)

[Claims] 1. A sensor housing in which a connector housing in which a connection terminal is inserted and a sensor housing recess in which a sensor engaging step is formed on the periphery of an opening. A pressure sensor element (21) having a case (30), a flange (23) engaged with the sensor locking step (40) and a pressure introduction pipe (24), and a pressure introduction pipe (24). A circuit which is inserted and supported on the outer periphery via a sleeve (26), and which is soldered (39) and (41) to the lead pin (25) expended from the pressure sensor element (21) and the connection terminal (32). Circuit board (27) having a pressure-introducing pipe (24)
And a stem (31) which has a pressure inlet (36) through which the sensor is inserted and which is tightly fitted on the outer peripheral surface of the sensor storage case (30), and which is housed in the pressure inlet (36). When the stem (31) is tightly fitted to the sensor storage case (30), the flange (23) provided on the pressure sensor element (21) is engaged with the sensor locking step (40).
A pressure sensor comprising a pressure positioning means (42) for resiliently pressing the pressure sensor element to position the pressure sensor element. 2. A lead pin (25) and a connection terminal (3).
The pressure sensor according to claim 1, wherein the thickness direction of the circuit board (27) soldered to (2) is floated in the sensor storage case (30).