JP2017211260A - Physical quantity measuring device - Google Patents

Abstract

Provided is a physical quantity measuring device in which a circuit board is securely held with respect to a cylindrical case and easy to assemble. SOLUTION: A cylindrical case 1, a first circuit board 41 and a second circuit board 42 arranged inside the cylindrical case 1, and a plate-like part 21 provided at one opening end of the cylindrical case 1. And a connection pin 5 that is fixed to the plate-like portion 21 and electrically connected to the second circuit board 42, and is connected to the first circuit board 41 on the inner periphery of the cylindrical case 1. A stepped portion 11B is formed, and the socket 420 is electrically connected to the connection pin 5 on the second circuit board 42 and allows the movement of the connection pin 5 in the board plate thickness direction and restricts movement in the board plane. Is provided, and a pressing portion 6 is provided along the outer peripheral portion 22 of the lid portion 2 to hold the first circuit board 41 against the step portion 11B. The lid portion 2 is pushed into the cylindrical case 1 and the holding portion 6 and the cylindrical case are pressed. The first circuit board 41 is sandwiched between the one step portion 11B. [Selection] Figure 2

Description

  The present invention relates to a physical quantity measuring apparatus.

A physical quantity measuring device such as a pressure transmitter includes a type in which a detection signal from a detection unit for detecting a physical quantity is received by a circuit board and a signal is output from the circuit board to the outside of the apparatus or a display unit.
In the conventional example of this type of physical quantity measuring device, the circuit board is arranged in parallel to the bottom surface of the holder, and the outer peripheral edge of the circuit board is equally spaced by a plurality of engaging portions and claw portions provided on the holder. (Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).

As another conventional example, the circuit board is arranged perpendicularly to the bottom surface of the holder, one end of the circuit board is joined to a support provided on the joint side, and the other end of the circuit board is connected to the support on the connector side. (Patent Document 5 and Patent Document 6).
Furthermore, as another conventional example, as a conventional example in which the circuit board is held in the case, a guide rail portion is provided in the case, and the concave connection portion of the printed wiring board is unevenly fitted to the convex portion of the guide rail portion. There is a thing (patent document 7).

Japanese Patent Laid-Open No. 2005-300196 JP-A-10-318871 JP 2007-155505 A Japanese Patent Laid-Open No. 11-351994 JP2013-205418A JP 9-138170 A JP 11-54961 A

In the conventional examples shown in Patent Literature 1, Patent Literature 2, Patent Literature 3, and Patent Literature 4, since the circuit board is pressed by the engaging portion or the claw portion, the circuit board is engaged when vibration is applied to the device. There is a risk of slipping off or coming off the head or nail.
In the conventional examples shown in Patent Document 5 and Patent Document 6, both ends of the circuit board must be joined to a holder or a joint, so that the workability of device assembly is poor.

  In the conventional example shown in Patent Document 7, since the guide rail portion and the printed wiring board are concavo-convex fitting, there is a possibility that the printed wiring board may move in the longitudinal direction of the guard rail portion. It is not always retained. In order to hold the printed wiring board securely in the case, it is conceivable to enlarge the convex guide rail part and make the connection part of the concave printed wiring board small. Becomes complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a physical quantity measuring device that can be securely assembled to a cylindrical case and that can be easily assembled.

  The physical quantity measuring device of the present invention includes a cylindrical case, a circuit board disposed inside the cylindrical case, a lid portion provided at one opening end of the cylindrical case and having a plate-like portion, A connection pin that is fixed to the plate-like portion and electrically connected to the circuit board, and a stepped portion that is engaged with the circuit board is formed on the inner periphery of the cylindrical case. A socket that is electrically connected to the connection pin and allows movement in the thickness direction of the substrate plate and restricts movement in the substrate plane is provided, and the stepped portion is arranged along the outer peripheral edge of the lid portion. A pressing part is provided, and the circuit board is sandwiched between the pressing part and the step part of the cylindrical case by pressing the lid part into the cylindrical case.

In the present invention, a pressing portion is provided in advance in the cylindrical case. Therefore, the cylindrical case and the pressing portion may be formed integrally, or may be formed separately and the pressing portion may be bonded and fixed to the cylindrical case.
Then, in order to assemble the cylindrical case, circuit board, and lid, the connection pin is fixed to the lid in advance, the circuit board is placed inside the cylindrical case, and the end of the connection pin is inserted into the socket of the circuit board. While pressing the lid toward the cylindrical case. Thereby, a circuit board is clamped by the press part provided in the cover part, and the level | step-difference part of a cylindrical case. In this state, even if the physical quantity measuring device is vibrated or shocked, the circuit board is restricted from moving in the board thickness direction by the pressing portion.
Therefore, in the present invention, the circuit board is moved in the thickness direction by the connection pin and the holding part provided on the lid part, the socket provided on the circuit board, and the step part provided on the cylindrical case. Therefore, reliable holding of the circuit board with respect to the cylindrical case can be easily realized.

In the present invention, it is preferable that the pressing portion has an elastic portion that biases the circuit board toward the stepped portion.
In this configuration, the circuit board is constantly urged toward the step portion by the elastic portion. Therefore, even if a gap is generated between the lid and the circuit board, the circuit board can be prevented from floating from the stepped part.

In the present invention, the elastic portion includes an elastic portion main body integrally formed with an arc-shaped portion provided in an arc shape along the outer peripheral edge of the lid portion, and a tip of the elastic portion main body provided on the circuit board. It is preferable that the elastic portion main body urges the contact portion toward the circuit board.
In this configuration, since the elastic portion is composed of the elastic portion main body and the contact portion integrally formed with the arc-shaped portion, the configuration of the elastic portion can be simplified.

In the present invention, it is preferable that the step portion has conductivity and an electrode is provided on a portion of the circuit board that engages with the step portion.
In this configuration, in order to connect the frame ground, it is only necessary to engage the electrode of the circuit board and the stepped portion, so that parts such as an electric wire and a lug terminal are not required.

In this invention, the structure by which the sealing part for sealing is provided between the said cylindrical case and the said cover part is preferable.
With this configuration, waterproof performance is improved with a simple structure.

In the present invention, a plurality of the circuit boards are arranged in the plate thickness direction, bonding pins and connectors are arranged between the circuit boards, and the adjacent circuit boards are fixed by the bonding pins and the connectors. The configuration is preferred.
In this configuration, by providing a joining pin as a reinforcement of the connector, the connector is not detached from the circuit board, and the vibration resistance of the physical quantity measuring device is improved.

The side view which fractured | ruptured a part of physical quantity measuring device concerning one Embodiment of this invention. Sectional drawing of a physical quantity measuring device. The disassembled perspective view which shows the principal part of a physical quantity measuring apparatus.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a side view in which a part of the physical quantity measuring device according to the present embodiment is broken, FIG. 2 shows a cross section of the physical quantity measuring device, and FIG. 3 shows a main part of the physical quantity measuring device. Yes.
1 to 3, the physical quantity measuring device is provided at a cylindrical case 1, a lid 2 provided at one open end of the cylindrical case 1, and the other open end of the cylindrical case 1. The detection unit 3, the circuit unit 4 having the first circuit board 41 and the second circuit board 42 disposed inside the cylindrical case 1, and the lid unit 2 electrically connected to the second circuit board 42. A plurality of connecting pins 5 to be attached are provided.

The cylindrical case 1 is made of metal and has a structure in which a large-diameter portion 11 to which the lid portion 2 is attached to the opening end portion 11A and a small-diameter portion 12 to which the detection portion 3 is attached to the opening end portion 12A are integrally formed. It is.
The opening end portion 11A of the large diameter portion 11 caulks the lid portion 2, and a step portion 11B that engages with the first circuit board 41 is formed in an annular shape on the inner periphery of the large diameter portion 11. As described above, since the cylindrical case 1 is made of metal, the step portion 11B has conductivity.

The lid portion 2 includes a disc-like plate-like portion 21 to which the connection pin 5 is fixed, an outer peripheral portion 22 that is an outer peripheral portion of the plate-like portion 21 and stands up toward the cylindrical case 1, and a plate-like portion 21 has a cylindrical portion 23 erected on the surface opposite to the direction in which the outer peripheral portion 22 is provided.
The plate-like portion 21 is provided with a window portion 21A that transmits infrared rays.
An O-ring 10 serving as a sealing part for sealing is provided between the outer peripheral part 22 and the large-diameter part 11. A groove 22 </ b> A for holding the O-ring 10 is formed along the outer periphery of the outer peripheral portion 22.
The cylindrical portion 23 is an input / output connector in which the connection pin 5 is housed, and a male screw is formed on the outer peripheral portion thereof.

A holding portion 6 that holds the first circuit board 41 against the stepped portion 11 </ b> B is provided along the opening end of the outer peripheral portion 22. The pressing portion 6 and the lid portion 2 are integrally formed from a synthetic resin.
The holding part 6 sandwiches the outer peripheral edge of the first circuit board 41 between the outer peripheral part 22 of the lid part 2 and the step part 11B of the cylindrical case 1 and is formed in an arc shape along the outer peripheral part 22. The arc-shaped portion 61 and the elastic portion 62 that is formed integrally with the arc-shaped portion 61 and biases the first circuit board 41 toward the stepped portion 11B.
The arc-shaped portion 61 is formed in an annular shape along the opening end of the outer peripheral portion 22, and the outer periphery thereof is fitted to the inner periphery of the large-diameter portion 11.
The elastic portion 62 and the arc-shaped portion 61 are partitioned by an L-shaped slit 6A as seen from FIG.

The elastic portions 62 are disposed at two locations located on opposite sides of the axis of the outer peripheral portion 22.
The elastic portion 62 is formed by bending an elastic portion main body 63 integrally formed on the arc-shaped portion 61 with a base end thereof, and bending from the distal end of the elastic portion main body 63 toward the first circuit board 41. It has an abutting portion 64 that abuts, and is formed in an L shape when viewed from FIG. The elastic portion main body 63 has an elastic force that urges the contact portion 64 toward the first circuit board 41.
When the first circuit board 41 is not pressed by the elastic portion 62, the tip of the contact portion 64 protrudes from the opening edge of the arc-shaped portion 61 (see the imaginary line in FIG. 1).

The detection unit 3 includes a joint 31 and a sensor module 32 provided on the joint 31.
The joint 31 includes a shaft portion 311 into which the fluid to be measured flows into an inner peripheral portion thereof, and a flange 312 that is integrally formed with the shaft portion 311 and engages with the opening end portion 12A of the small diameter portion 12. A male screw is formed on the outer peripheral portion of the shaft portion 311 so as to be screwed into a member to be attached (not shown).
The sensor module 32 includes a module main body 321 joined to the joint 31 by welding, and a detection unit (not shown) made of a strain gauge formed on the module main body 321. The module main body 321 has a diaphragm part 322 in which a detection part is formed. When the diaphragm part 322 is displaced with the pressure of the fluid to be measured, the detection part detects the displacement. A signal output from the detection unit 3 is sent to the outside via the circuit unit 4 and the connection pin 5.

A specific structure of the circuit unit 4 is shown in FIG.
In FIG. 3, the circuit unit 4 includes, in addition to the first circuit board 41 and the second circuit board 42, bonding pins 43 and connectors 44 arranged between the first circuit board 41 and the second circuit board 42. I have.
A wire 40 that receives a signal from the detection unit 3 is connected to the first circuit board 41 (see FIGS. 1 and 2).

An electrode 41A for a frame ground is formed on a portion of the first circuit board 41 that engages with the step portion 11B.
On the surface opposite to the surface facing the first circuit substrate 41 of the second circuit substrate 42, a light emitting / receiving unit 45 facing the window portion 21A is provided. The light emitting / receiving unit 45 is an element that receives or transmits an infrared signal from an external communication device (not shown) through the window portion 21A.
The first circuit board 41 and the second circuit board 42 are provided with electronic components (not shown). The electronic component includes an arithmetic circuit that calculates a pressure value based on a signal detected by the detection unit 3, a setting change circuit that is connected to the light emitting / receiving unit 45 and changes a setting value of the detection unit 3, and other circuits. Yes.

The second circuit board 42 is provided with a socket 420 that is electrically connected to the connection pin 5 and that allows the connection pin 5 to move in the board plate thickness direction and restrict movement in the board plane. There are a number of sockets 420 corresponding to the number of connection pins 5.
The connection pin 5 has a press-fit portion 5A for press-fitting into the plate-like portion 21 of the lid portion 2 and a press-fit restricting portion 5B for restricting the press-fit to the plate-like portion 21 at a midway position thereof. The press-fit portion 5A and the press-fit restricting portion 5B are disposed along the longitudinal direction of the connection pin 5.
The joining pin 43 is made of metal so as to fix and energize the first circuit board 41 and the second circuit board 42.
The connector 44 includes a connector main body 440 fixed to the surface of the first circuit board 41 facing the second circuit board 42, and a connector support 441 fixed to the surface of the second circuit board 42 facing the connector main body 440. Have
The first circuit board 41 and the second circuit board 42 that are adjacent to each other are fixed by the bonding pins 43 and the connector 44.

Next, a method for assembling the physical quantity measuring device of this embodiment will be described.
First, as shown in FIG. 3, the connector main body 440 and a part of the electronic components are installed on the first circuit board 41, and the connector support portion 441, the light emitting / receiving unit 45, and the rest of the electronic components are installed on the second circuit board 42 To do. The circuit part 4 is assembled by connecting the first circuit board 41 and the second circuit board 42 with the joining pins 43 and connecting the connector body 440 and the connector support part 441.
And the 1st circuit board 41 and the detection part 3 are connected with the wire 40 (refer FIG.1 and FIG.2).

Further, the connection pin 5 is attached to the plate-like portion 21 and the circuit portion 4 is accommodated in the lid portion 2. Then, the connection pin 5 is inserted into the socket 420 of the second circuit board 42. The lid portion 2 in a state where the O-ring 10 is engaged with the outer peripheral portion 22 is pushed into the cylindrical case 1. The outer peripheral portion of the first circuit board 41 is sandwiched between the outer peripheral portion 22 of the lid portion 2 and the step portion 11B of the cylindrical case 1. When the lid 2 is pushed into the cylindrical case 1, the lid 2 is caulked and fixed at the open end 11 </ b> A of the cylindrical case 1.
Even after the lid portion 2 is pushed into the cylindrical case 1, the first circuit board 41 remains pressed against the step portion 11B by the elastic force of the elastic portion 62.

In the present embodiment, the following effects can be achieved.
(1) A step portion 11B that engages with the first circuit board 41 is formed on the inner periphery of the cylindrical case 1, and the second circuit board 42 is electrically connected to the connection pin 5 and connected to the connection pin 5. Is provided with a socket 420 that allows movement in the board plate thickness direction and restricts movement in the board plane, and a holding part 6 that holds the first circuit board 41 against the step part 11B along the outer peripheral part 22 of the lid part 2 is provided. The lid portion 2 is pushed into the cylindrical case 1, and the first circuit board 41 is held between the pressing portion 6 and the stepped portion 11 </ b> B of the cylindrical case 1. As a result, even if the physical quantity measuring device is vibrated or shocked, the first circuit board 41 is restricted from moving in the board thickness direction by the pressing portion 6. Reliable holding of the circuit board 42 with respect to the cylindrical case 1 can be easily realized.

(2) The pressing part 6 urges the first circuit board 41 to the stepped part 11 </ b> B provided in the arcuate part 61 provided in an arcuate shape along the outer peripheral part 22 of the lid part 2 and the arcuate part 61. Since the elastic portion 62 is included, even if a gap is generated between the lid portion 2 and the first circuit board 41, the first circuit board 41 can be prevented from floating from the step portion 11B. Therefore, also from this point, the first circuit board 41 and the second circuit board 42 can be reliably held with respect to the cylindrical case 1.

(3) Since the pressing portion 6 and the lid portion 2 are integrally formed, the mounting operation of the pressing portion 6 to the lid portion 2 is not required, and the assembly operation of the apparatus is facilitated.

(4) The elastic portion 62 includes an elastic portion main body 63 integrally formed with the arc-shaped portion 61 and a contact portion 64 provided on the elastic portion main body 63 and having a tip abutting on the first circuit board 41. Since the part main body 63 is configured to urge the contact part 64 toward the first circuit board 41, the configuration of the elastic part 62 can be simplified.

(5) Since the cylindrical case 1 having the step portion 11B is metallic, and the electrode 41A is provided in the portion of the first circuit board 41 that engages with the step portion 11B, in order to connect the frame ground No parts such as electric wires or lug terminals are required.

(6) Since the O-ring 10 as a sealing part for sealing is provided between the cylindrical case 1 and the lid 2, the waterproof performance is improved with a simple structure called the O-ring 10.

(7) Since the circuit board is composed of the first circuit board 41 and the second circuit board 42 arranged in the plate thickness direction, the area of the circuit board is reduced as compared with the case where the circuit board is composed of one circuit board. be able to. In addition, a joining pin 43 and a connector 44 are disposed between the first circuit board 41 and the second circuit board 42, and the first circuit board 41 and the second circuit board 42 are formed by the joining pin 43 and the connector 44. And are fixed. That is, since the joining pin 43 is provided as a reinforcement of the connector 44, the connector 44 is not detached from the first circuit board 41 and the second circuit board 42, and the vibration resistance and vibration resistance of the physical quantity measuring device are reduced. improves.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the elastic part 62 is arranged at two positions that are located on opposite sides of the axis of the outer peripheral part 22 of the lid part 2. The number provided is not limited to the above embodiment. That is, the elastic part 62 may be a plurality of one place, three places or more. However, a plurality of elastic portions 62 are preferably arranged at equal intervals along the outer periphery of the outer peripheral portion 22.

Furthermore, the arc-shaped portion 61 is not limited to one formed in an annular shape, and may be formed from one or a plurality of arcs having a predetermined angle.
Further, the step portion 11B is not limited to an annular shape, and may be arcuate.
In the embodiment, the lid portion 2 and the pressing portion 6 are integrally formed. However, in the present invention, these may be formed separately, and in this case, the pressing portion 6 is bonded and fixed to the lid portion 2. But you can.

Further, the circuit board is composed of the first circuit board 41 and the second circuit board 42, but one or a plurality of circuit boards may be arranged between them. May be composed of one sheet. In the case where the second circuit board 42 is omitted and the first circuit board 41 is used, a socket 420 is provided on the first circuit board 41.
Furthermore, although the cylindrical case 1 is made of metal, the cylindrical case 1 may be made of synthetic resin in the present invention. Even when the cylindrical case 1 is made of a synthetic resin, if a conductive portion is formed in the stepped portion 11B, there is an effect that parts such as an electric wire and a lug terminal are not required to connect the frame ground. Can do.
In the above embodiment, the physical quantity measuring device is used for pressure measurement. However, the present invention is not limited to this, and can be applied to, for example, differential pressure measurement and temperature measurement.

DESCRIPTION OF SYMBOLS 1 ... Cylindrical case, 10 ... O-ring (sealing seal part), 11 ... Large diameter part, 11A ... Open end part, 11B ... Step part, 12 ... Small diameter part, 12A ... Open end part, 2 ... Cover part, DESCRIPTION OF SYMBOLS 21 ... Plate-shaped part, 22 ... Outer peripheral part, 3 ... Detection part, 4 ... Circuit part, 40 ... Wire, 41 ... 1st circuit board, 41A ... Electrode, 42 ... 2nd circuit board, 420 ... Socket, 43 ... Joining 44, connector, 5 ... connection pin, 6 ... pressing part, 61 ... arc-shaped part, 62 ... elastic part, 63 ... elastic part body, 64 ... contact part, 6A ... slit

Claims (6)

A cylindrical case, a circuit board disposed inside the cylindrical case, a lid portion provided at one opening end of the cylindrical case, and having a plate-like portion; and the circuit fixed to the plate-like portion. A connection pin electrically connected to the substrate,
On the inner periphery of the cylindrical case, a step portion that engages with the circuit board is formed,
The circuit board is provided with a socket that is electrically connected to the connection pin and allows the movement of the connection pin in the board plate thickness direction and restricts movement in the board plane.
A pressing part is provided along the outer peripheral edge of the lid part to hold the circuit board against the stepped part,
The physical quantity measuring device, wherein the lid is pushed into the cylindrical case and the circuit board is sandwiched between the pressing portion and the stepped portion of the cylindrical case. The physical quantity measuring device according to claim 1,
The physical quantity measuring device, wherein the pressing portion includes an elastic portion that biases the circuit board toward the stepped portion. The physical quantity measuring device according to claim 2,
The elastic portion includes an elastic portion main body integrally formed with an arc-shaped portion provided in an arc shape along the outer peripheral edge of the lid portion, and an abutment where the tip abuts on the circuit board provided in the elastic portion main body. And the elastic portion main body urges the abutting portion toward the circuit board. The physical quantity measuring device according to any one of claims 1 to 3,
The step portion has conductivity, and an electrode is provided on a portion of the circuit board that engages with the step portion. In the physical quantity measuring device according to any one of claims 1 to 4,
A physical quantity measuring device, wherein a sealing part for sealing is provided between the cylindrical case and the lid part. In the physical quantity measuring device according to any one of claims 1 to 5,
A plurality of the circuit boards are arranged in the plate thickness direction, bonding pins and connectors are arranged between the circuit boards, and the adjacent circuit boards are fixed by the bonding pins and the connectors. A physical quantity measuring device characterized by.

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