JP2886758B2 - Connection structure of terminal to printed circuit board in sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for connecting terminals of a sensor to a printed circuit board.

[0002]

2. Description of the Related Art As a connection structure of terminals to a printed circuit board in a conventional sensor, for example, there is one shown in FIG. In FIG. 7, reference numeral 1 denotes a main body cover, and the main body cover 1 is integrally formed with a main body 1A. An outer cover 3 having a smoke inlet 2 formed below the body cover 1.
Is installed.

Reference numeral 4 denotes a terminal. The terminal 4 is inserted into the main body 1A, and a terminal fitting 5 is fixed to the terminal 4 with a screw 6. The terminal fitting 5 is inserted into the contact fitting 7,
Is connected to the printed circuit board 8. In this way, a power supply voltage or the like is supplied to the printed circuit board 8 via the terminal 4, the terminal fitting 5, and the contact fitting 7. The contact fitting 7
As shown in FIG. 8, the main body 7A is formed of a leaf spring,
It is constituted by a pair of contact pieces 7B and 7C and a pair of feet 7D and 7E.

As shown in FIG. 9, a pair of contact pieces 7B, 7
The electrical connection is obtained by inserting the terminal fitting 5 between C and pressing the contact pieces 7B and 7C. A pair of feet 7D,
7E is inserted into holes 8A and 8B formed in the printed circuit board 8 and soldered. Reference numeral 8C denotes an insertion hole for the terminal fitting 5 formed on the printed circuit board 8.

[0005]

However, in such a conventional connection structure of the terminal to the printed circuit board by the contact fitting of the leaf spring, when the size of the sensor is reduced, the spring elasticity is weak, and However, there is a problem that poor conduction occurs due to the low restorability in shape.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem. By using a linear elastic body as a contact fitting, it is possible to reliably prevent the occurrence of a conduction failure, and to automatically insert the contact. It is an object of the invention to provide a connection structure for terminals of a possible sensor to a printed circuit board.

[0007]

In order to achieve the above object, the present invention relates to a method of printing a terminal 23 in a sensor for connecting a terminal 23 to a printed circuit board 15 using a contact fitting 25 as shown in FIG. The contact fitting 25 is made of a substantially clip-shaped linear elastic body and has bent portions 25C and 25D whose both ends are bent.
And holding portions 25A, 2 for holding the terminal 23 from both sides.
5B, a positioning portion 25E formed continuously on one end side of the holding portions 25A, 25B,
A and 25B are characterized in that they have a contact portion 25F that adheres substantially parallel to one of them.

Further, the present invention relates to the printed circuit board 15.
A pair of insertion holes 15A, 15B into which the bent portions 25C, 25D are inserted, and soldering portions 15D, 15E, 15F for soldering the contact fitting 25 to the printed circuit board 15.
And positioning hole 1 into which positioning portion 25E is inserted.
5C and a terminal insertion hole 15G into which the terminal 23 is inserted.

[0009]

According to the present invention having such a configuration, the contact fitting 25 is formed of a substantially clip-like linear elastic body, and has the bent portions 25C and 25D whose both ends are bent, and holds the terminal from both sides. Holding portions 25A, 25B, and holding portions 25A, 25B,
The terminal 23 is inserted into the contact fitting 25 because it has a positioning portion 25E formed continuously on one end side of the one end 25B and a contact portion 25F that adheres substantially parallel to one of the holding portions 25A and 25B. In this case, not only the holding portions 25A and 25B but also the contact portion 25F come into contact with each other, so that the conventional two-point contact comes into three-point contact and the terminal 23 is elastically pressed by the linear elastic body. Electrical connection can be made more reliably. As a result, the occurrence of conduction failure can be reliably prevented.

[0010] Further, since the contact portion 25F is provided in close contact with one of the holding portions 25A and 25B in a substantially parallel manner, the contact fitting 25 is not entangled in the ball feeder, and the direction is imparted by the positioning portion 25E. As a result, the contact fitting 25 can be automatically inserted into the printed circuit board 15 by the robot. Furthermore, the insertion direction of the terminal 23 is not limited to one direction,
Can also be inserted from the opposite direction.
The shape of the cross section is not limited to the circular shape,
It may have a square shape or the like.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of the present invention. FIG. 2 is a sectional view when an ionization type smoke detector is used as a detector. In FIG. 2, reference numeral 11 denotes an internal ionization chamber, and the internal ionization chamber 11 is partitioned by an insulator 12 and an intermediate electrode 13. An internal electrode 14 containing a radiation source is housed in the internal ionization chamber 11, and the internal electrode 14 is electrically connected to an upper printed circuit board 15 with support by an insulator 12.

An external electrode 16 is located at a position covering the outside of the internal ionization chamber 11 partitioned by the insulator 12 and the intermediate electrode 13.
Are arranged, and the external ionization chamber 17 is partitioned by the external electrodes 16. The external ionization chamber 17 allows smoke to flow in from the outside through a smoke inlet 19 formed in the outer cover 18. The intermediate electrode 13 is fixed and supported on the insulator 12, and the external electrode 16 is fixed and supported on the insulator 12 and the outer cover 18.

An opening 20 is provided at the position of the intermediate electrode 13 relative to the radiation source of the internal electrode 14 housed in the internal ionization chamber 11.
Are formed. Reference numeral 21 denotes an FET. The FET 21 is mounted on the printed circuit board 15 and the intermediate electrode 13.
Connected to. When a power supply voltage is applied between the external electrode 16 and the intermediate electrode 13 and between the intermediate electrode 13 and the internal electrode 14, the internal ionization chamber 11 and the external ionization chamber 1
The ion pair generated by the radiation source is moved from the negative pole to the positive pole side by the generated electric field 7, a weak current flows, and a VI characteristic for generating a predetermined inter-electrode voltage is obtained.

When the smoke flows into the external ionization chamber 17, the ion pair adheres to the smoke particles, and the moving speed is reduced. As a result, the ion current flowing between the intermediate electrode 13 and the external electrode 16 is reduced. Voltage rises and this external ionization chamber 17
And detects that the smoke density has reached a predetermined value, based on the change in the VI characteristic of FIG. Reference numeral 22 denotes a main body cover. The main body cover 22 has a main body (insulator) 22A.
Are integrally formed. A terminal 23 is provided on the main body 22A.
Is inserted and caulked and fixed by the terminal fittings 24 fixed to the main body cover 22.

The terminal 23 is connected to the printed circuit board 15 via a contact fitting 25. Next, connection of the terminal 23 to the printed circuit board 15 by the contact fitting 25 will be described with reference to FIG. In FIG. 1, reference numeral 25 denotes a contact fitting, and the contact fitting 25 is made of a linear elastic body formed substantially in a clip shape. 25A and 25B are holding parts, and the holding parts 25A and 25B
25B are formed substantially parallel to each other, and hold the terminal 23 from both sides. 25C and 25D are bent portions, and the bent portion 25
C and 25D are formed by bending both ends of the contact fitting 25. The bent portions 25C and 25D are connected to the printed circuit board 15.
Are inserted into the insertion holes 15A and 15B formed in the above. The distance between the holding portions 25A and 25B is set slightly smaller than the diameter of the terminal 23.

Reference numeral 25E denotes a positioning section, and the positioning section 2
5E is a positioning hole 15 formed in the printed circuit board 15 which is formed by bending and continuing from the holding portion 25B.
It is inserted into C and performs positioning. Also, the positioning unit 25
E has a direction at the time of automatic insertion. That is, when the contact fitting 25 is automatically inserted into the printed circuit board 15, a number of mounted components are aligned using a machine called a ball feeder.
, So as to give directionality at the time of alignment.

Reference numeral 25F denotes a contact portion.
F is formed in close contact with the holding portion 25B, which is continuous with the positioning portion 25E, substantially in parallel. When the terminal 23 is inserted from above, the contact portion 25F is shifted downward from the holding portion 25B and comes into contact with the terminal 23. That is, the terminal 23 is clamped from both sides by the clamping portions 25A and 25B,
The contact is made at two points, and the contact is made at the three points by making contact with the contact portion 25F. This allows
Ensure electrical connection. Further, if there is a gap between the holding portion 25B and the contact portion 25F, the contact fittings 25 are entangled in the ball feeder. Automatic insertion into the printed circuit board 15 by a robot is enabled.

In FIG. 1, reference numerals 15D, 15E and 15F denote soldering portions, and the contact fittings 25 are soldered to the printed circuit board 15 at the soldering portions 15D, 15E and 15F. 15G
Is a terminal insertion hole formed in the printed circuit board 15, and the terminal 23 is inserted into the terminal insertion hole 15G via the contact fitting 25. In this embodiment, the terminal 23 has a circular cross section and a tip portion having a conical shape.

Next, the operation will be described. After aligning the contact fittings 25 with the ball feeder, the robot automatically inserts the contact fittings 25 into the printed circuit board 15. That is,
The bent portions 25C and 25D of the contact fitting 25 are
5 is inserted into the insertion holes 15A and 15B, and the positioning portion 25E is inserted into the positioning hole 15C of the printed circuit board 15.

Then, the soldering portions 15D, 15E, 15
F, the contact fitting 25 and the printed circuit board 15 are soldered.
Next, the terminal 23 is inserted into the contact fitting 25, and is inserted into the terminal insertion hole 15G of the printed circuit board 15. At this time, as shown in FIGS. 3 and 4, the contact portion 25F is pressed by the terminal 23, moves downward, and contacts the terminal 23 below the holding portion 25B.

As described above, the terminal 23 is held from both sides by the holding portions 2.
5A and 25B, and furthermore, the contact portion 25F makes contact, so that the conventional two-point contact makes three-point contact. Further, by fixing the positioning portion 25E, the contact fitting 25 of the terminal 23 is formed. Parts 25A, 25 when inserted into
By limiting the extent of B, electrical connection can be ensured. As a result, occurrence of a conduction failure can be prevented.

The contact portion 25 is parallel to the holding portion 25B.
Since F is provided, there is no gap between the close contact portion 25F and the holding portion 25B, so that the contact fitting 25 does not become entangled in the ball feeder. Further, since the directivity is given by the positioning portion 25E, the contact fitting 25 can be automatically inserted into the printed circuit board 15 by the robot.

Further, as shown in FIG. 1, the terminal 23 can be inserted not only from above the contact fitting 25 but also from the opposite side of the printed circuit board 15, as shown in FIG. In this case, the soldering portion may be provided on the opposite side of the printed board 15. Thus, the terminal 23
The insertion direction is not limited, and the degree of freedom can be improved.

FIG. 5 is a diagram showing a second embodiment of the present invention. In FIG. 5, reference numeral 26 denotes a terminal, and the terminal 26 is connected to the printed circuit board 15 via the contact fitting 25.
The contact fitting 25 has a configuration similar to that of the first embodiment. The terminal 26 has a substantially square cross section at the tip 26A. The shape of the terminal 26 is not limited to a circular cross section. That is, by using the contact fitting 25,
Various types of terminals 26 can be reliably connected.

FIG. 6 is a view showing a third embodiment of the present invention. In FIG. 6, reference numeral 15 denotes a printed board, and the printed board 15 is fixed on an insulator 27. Reference numeral 28 denotes an internal electrode as a terminal, and the internal electrode 28
5 is connected to the printed circuit board 15. Contact fitting 2
Reference numeral 5 has the same configuration as the above embodiment. Internal electrode 2
8 is inserted from the opposite side of the printed circuit board 15. Thus, even if the insertion direction changes, the terminal can be connected to the printed circuit board 15 via the contact fitting 25.

In the above embodiment, an ionization type smoke detector has been described as an example. However, any type of detector such as a photoelectric type smoke detector and a thermal type detector can be used.

[0027]

As described above, according to the present invention, a substantially clip-shaped linear elastic body is used as the contact fitting, so that three-point contact can be performed and electrical connection can be reliably performed. Since it can be performed, occurrence of conduction failure can be prevented. In addition, since the contact fitting is shaped so as to prevent entanglement and give directionality, automatic insertion becomes possible.

Further, the insertion direction of the terminal is not limited to one direction, and the terminal can cope with a change in the shape of the terminal.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the entire sensor.

FIG. 3 is a front view showing an inserted state of a terminal;

FIG. 4 is a sectional view showing an inserted state of a terminal;

FIG. 5 is a diagram showing a second embodiment of the present invention.

FIG. 6 is a diagram showing a third embodiment of the present invention.

FIG. 7 shows a conventional example.

FIG. 8 is a front view of a contact fitting.

FIG. 9 is a diagram showing a connection state;

[Explanation of symbols]

 11: Internal ionization chamber 12: Insulator 13: Intermediate electrode 14: Internal electrode 15: Printed circuit board 15A, 15B: Insertion hole 15C: Positioning hole 15D, 15E, 15F: Soldering part 15G: Terminal insertion hole 16: External electrode 17: External ionization chamber 18: Outer cover 19: Smoke inlet 20: Opening hole 21: FET 22: Main body cover 22A: Main body 23: Terminal 24: Terminal metal fitting 25: Contact metal fitting 25A, 25B: Holding parts 25C, 25D: Bent part 25E: Positioning part 25F: Adhesive part 26: Terminal 26A: Tip part 27: Insulator 28: Internal electrode

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G08B 17/00 H01R 9/09

Claims (2)

(57) [Claims] 1. A connection structure for connecting a terminal to a printed circuit board in a sensor for connecting the terminal and the printed circuit board using the contact fitting, wherein the contact fitting is made of a substantially clip-shaped linear elastic body;
A bent portion having both ends bent, a holding portion for holding the terminal from both sides, a positioning portion continuously formed on one end side of the holding portion, and a substantially parallel contact with one of the holding portions. A connection structure for connecting a terminal to a printed circuit board in a sensor, wherein the connection portion has a contact portion that makes contact. A pair of insertion holes into which the bent portion is inserted, a soldering portion for soldering the contact fitting to the printed substrate, and a positioning hole into which the positioning portion is inserted. 2. The structure according to claim 1, further comprising a terminal insertion hole into which the terminal is inserted.