JP2535643B2 - Sensor built-in board structure - Google Patents

Description

The present invention relates to a sensor-embedded structure for a sensor incorporated in a sensor of a printed circuit board on which a sensor circuit is mounted.

[Prior Art] In recent years, miniaturization and thinning of fire detectors have been promoted, and miniaturized and thinned fire detectors have been put to practical use by a fraction of the volume of conventional products.

As for the sensor circuit to be built into the sensor as the sensor becomes smaller and thinner, chip parts are used and a double-sided mounting type is used as the printed circuit board for high density circuit mounting at the same time. We are trying to expand the area.

Therefore, even if the area of the circuit housing section is reduced by making the sensor smaller and thinner, the so-called alert signal is sent by turning on when the fire detection signal reaches the set threshold due to the variety of chip parts and the adoption of the double-sided printed circuit board. For on-off type sensors, the sensor circuit can be implemented without problems.

[Problems to be Solved by the Invention] By the way, in recent years, the fire detection signal itself,
That is, a so-called analog type sensor that transmits an analog fire detection signal from a sensor to a receiver and judges a fire on the receiver side has been put into practical use.

However, the analog type sensor requires a transmission control circuit that determines the call from the receiver and transmits the analog detection information in addition to the on / off type sensor circuit. However, there is a problem in that the circuit housing portion of the sensor that is small and thin, which is not a problem in the on-off type, has a short circuit mounting area, and the sensor structure that is thin and thin cannot be diverted.

Therefore, it is considered to mount the transmission circuit section separately from the sensor body to the sensor base, but a new circuit housing is secured on the sensor base side, which complicates the overall structure and increases costs. Furthermore, since the sensor body is detachably attached to the sensor base, there is a problem that the fitting terminal structure between the two becomes complicated due to an increase in the number of signal lines.

The present invention has been made in view of such conventional problems, and paying attention to the fact that there is a margin in the dimension in the height direction even with a small and thin sensor structure, and mounting of the sensor circuit It is possible to provide a sensor board mounting structure in which the area can be expanded and a circuit can be mounted even if it is an analog type including a transmission control circuit, and components can be easily mounted and mounted on a circuit board. To aim.

[Means for Solving the Problem] In order to achieve this object, the present invention incorporates a printed circuit board on which a sensor circuit is mounted in a circuit housing portion formed behind a fire detection portion protected by a cover portion. In the structure sensor, the sensor circuit is divided into a first printed circuit board and a second printed circuit board, and a chip component is mounted on at least one surface of the first printed circuit board. A plurality of first connector pins for electrical connection and second connector pins for supporting and fixing are projected upward and downward through the insulating body, and at the tips of the first connector pins protruding below the insulating body. The contact pin portion side is mounted on one surface of the first printed circuit board by a connector having a contact pin portion extending in the lateral direction, and a second printed circuit board is overlaid to form the second connector pin. First , The first connector board and the first and second printed circuit boards are fitted into through holes provided in the second printed circuit board to position and support and fix the first and second printed circuit boards. It is characterized in that it is electrically connected by soldering with and is mechanically supported and fixed at the same time and is incorporated in the circuit housing portion.

[Operation] According to the circuit board built-in structure of the present invention having such a configuration, even if the sensor structure is made small and thin, there is a space in the height direction of the circuit housing portion. From
Two printed circuit boards can be mounted in a stacked state with a connector in between, and the circuit mounting area is approximately doubled. Even an analog sensor circuit equipped with a transmission control circuit is sufficient. It can be installed in the circuit housing inside the sensor body with a margin.

In addition, a connector is interposed between two printed circuit boards, and the two pins can be electrically and mechanically connected and fixed by soldering the connector pins and the circuit pattern to each other. A separate structure is not required, and a hierarchical built-in structure can be realized through the process of soldering the electric components to the printed circuit board, and the production efficiency is high, so that the cost can be reduced.

[Embodiment] FIG. 1 is a configuration diagram of an embodiment showing one embodiment of the present invention.

In FIG. 1, reference numeral 25 denotes a sensor body, and the fire detection unit 10 is incorporated in an outer cover 28 attached to the lower center of the sensor body. In this embodiment, the fire detection unit 10 employs a scattered light type smoke detection mechanism. That is, the fire detection unit 10
A smoke detection space 30 is formed in the center of the smoke detection space, and smoke can flow into the smoke detection space 30 from a smoke inlet 32 formed around the outer cover. Light emitting element 34 and light receiving element for smoke detection space 30
36 are provided. Since the light receiving element 36 is a scattered light type, it is arranged at a position displaced from the facing position where the light from the light emitting element 34 does not directly enter, and the light from the light emitting element 34 due to the smoke flowing into the smoke detection space 30 Receive scattered light.

A circuit accommodating portion 12 is formed behind the fire detecting portion 10, that is, in the upper portion. That is, the circuit accommodating portion 12 is hermetically formed by fitting the upper surface of the fire detecting portion 10 from below to the concave portion formed in the center of the sensor main body 25 and adhesively fixing it. A detachable lid 38 is provided on the upper surface of the circuit housing portion 12, and the lid 38 can be removed to operate the address setting switch on the circuit board incorporated in the circuit housing portion 12.

A first printed circuit board 14 and a second printed circuit board 16 are incorporated in the circuit housing portion 12 in a state of being superposed with a connector 18 interposed therebetween. The back surface of the first printed circuit board 14 located on the lower side is closely fixed to the upper surface of the fire detection unit 10 located on the lower side, and penetrates the lead terminals of the light emitting element 34 and the light receiving element 36 and is fixed by soldering. .

The sensor circuit is separately mounted on the first printed circuit board 14 and the second printed circuit board 16 which are stacked vertically.
The electrical connection between the divided sensor circuits is made by the connector 18. At the same time, hierarchical support and fixing of the second printed circuit board 16 on the first printed circuit board 14 is also performed only by the connector 18. Circuit patterns are formed on the surfaces of the printed circuit boards 14 and 16 that face each other.
40 have been implemented. The printed boards 14 and 16 are of double-sided mounting type.

FIG. 2 is a connector used in the board built-in structure of FIG.
18 is taken out and shown. The front view is shown in FIG.
The figure (b) shows a bottom view and the figure (c) shows a side view.

In FIG. 2, a connector 18 has a rectangular parallelepiped-shaped connector body 20 formed of a heat-resistant insulating material, and has two supporting and fixing connector pins 24 that vertically penetrate through both ends of the connector body 20. 2 are arranged in parallel between the supporting and fixing connector pins 24 so that a total of 6 electrical connecting connector pins 22 are vertically penetrated and fixed.

In the six connector pins 22 for electrical connection, the tips of the connector pins projecting to the lower side of the connector body 20 are integrally formed with contact pin portions 26 that are bent and extend in the lateral direction. As is apparent from the side view of FIG. 2 (c), the contact pin portion 26 has a supporting and fixing connector pin 24 protruding downward.
It extends laterally in front of the tip of the. As shown in FIG. 1, when the connector 18 is mounted on the first printed circuit board 14, the contact pin 26 is placed on the surface of the printed circuit board 14 on the circuit pattern to prevent the soldering. This is to secure a sufficient contact area when attaching. On the other hand, the connector pin 24 for supporting and fixing is fitted into the through hole of the printed circuit board 14 to perform positioning and supporting and fixing.

FIG. 3 shows the fire detection unit 10 in the embodiment of FIG.
Printed circuit board 14, connector 18 and second printed circuit board
FIG. 16 is an assembly exploded view of 16.

The manufacturing process will be described below with reference to FIG.

First, the chip component 40 and necessary circuit elements are mounted on the first printed circuit board 14, and the connector 18 is mounted by fitting the support fixing connector pins 24 on both ends into the mounting holes, and in this state, reflow soldering is performed. Through the process, the chip component 40 and the connector 18 are fixed by soldering.

At the same time, chip components for the second printed circuit board 16 are also included.
Circuit components such as 40 and address setting switch 42 are placed and similarly flown to the reflow soldering process and fixed by soldering. Further, the fire detecting section 10 is also assembled as shown by incorporating the light emitting element 34 and the light receiving element 36.

After the fire detection unit 10 and the first and second printed circuit boards 14 and 16 are assembled, the first printed circuit board 14 is first placed on the upper surface of the fire detection unit 10 and brought into close contact therewith, and the light emitting element 34 and the light receiving element The lead terminals of 36 are fixed to the pattern on the printed circuit board 14 by soldering. Subsequently, the supporting / fixing connector pin 24 and the electrical connecting connector pin 22 projecting above the connector 18 soldered and fixed to the first printed circuit board 14.
Are fitted into the through holes of the second printed circuit board 16 and assembled so as to be superposed. And finally, the connector pins 22, 2 of the connector 18 protruding above the second printed circuit board 16
Fix 4 with solder.

FIG. 4 shows the first printed circuit board 14 and the second printed circuit board 14 shown in FIG.
FIG. 6 is a circuit diagram showing an example of a sensor circuit separately mounted on the printed circuit board 16 of FIG.

In FIG. 4, the sensor circuit is divided into upper and lower parts at a central one-dot chain line, the upper circuit portion 100 is mounted on the first printed circuit board 14, and the lower circuit portion 200 is mounted on the second printed circuit board 16. Will be implemented in.

The terminals L and C of the circuit section 100 are connected to a signal line for power supply from the receiver, and the diode bridge 44 makes the connection polarity non-polar. A constant voltage circuit 46 is provided following the diode bridge 44, and a light emitting element is provided on the output side of the constant voltage circuit 46.
An LED drive circuit 48 that drives 34 and an LED drive circuit 50 that drives the indicator lamp 45 to emit light are provided. The light scattered from the light emitting element 34 due to smoke is received by the light receiving element 36 and input to the amplifier circuit 52. The light receiving signal from the amplifier circuit 52 is sampled and held by the sample and hold circuit 54, and then applied to the analog output control circuit 56 and the on / off output control circuit 58.

Each of the LED drive circuits 48, 50, the amplifier circuit 52, the sample hold circuit 54, the analog output control circuit 56, and the on / off output control circuit 58 operates under timing control from the circuit section 200 side.

The analog output control circuit 56 outputs the received light signal voltage obtained from the sample hold circuit 54 to the voltage-current conversion circuit 65 on the diode bridge 44 side, converts it into a current signal of 4 to 20 mA and sends it to the receiver. Also, the on / off output control circuit 58
Compares the received light signal voltage from the sample hold circuit 54 with a predetermined threshold value by a comparator, and when the comparator output when the received light signal voltage exceeds the threshold voltage is obtained, for example, twice in succession, a fire occurs. Judgment and report output voltage to voltage-current conversion circuit 65
The alarm current, that is, the fire bit signal is sent to the receiver at a timing different from the analog output.

On the other hand, a circuit centering on the transmission control circuit unit that determines and responds to a call from the receiver is provided on the lower circuit unit 200 side.

Here, the transmission control between the sensor and the receiver will be described with reference to the timing chart of FIG.

First, after the reset pulse, the receiver sends n calling clocks corresponding to the number n of connected sensors, and the reset pulse and the calling clock are repeatedly sent. On the sensor side, the reset pulse and the calling clock are detected, the counter for counting the address is cleared by the reset pulse, and then the counter is incremented by 1 every time the clock pulse is detected to generate the calling address. The calling address counted by the counter is compared with the sensor address set in the sensor, and if an address match is obtained, it is judged to be its own calling and a necessary response is made.

FIG. 5 shows the response operation of the sensor in which “address = 2” is set, and when the second calling clock is received, the own calling is discriminated, and the idle time until the next calling clock is obtained, For example, it is divided into 9 parts and assigned as states 1 to 9, for example, a normal signal response is made in state 2, a classification signal response is made in state 3, an analog detection signal response is made in state 4, and further state 5 is made.
Will start responding to the fire bit signal.

In order to perform the transmission control shown in FIG. 5, a clock detection circuit 60, a control IC 62, an address setting circuit 64, a reset circuit 66, timing pulse generation circuits 68, 70 A voltage-current conversion circuit 72 for response, an abnormality determination circuit 74, and a voltage-current conversion circuit 76 for type response are provided. Reference numeral 78 is a constant voltage circuit, and 80 is a reference clock generation circuit.

More specifically, the clock detection circuit 60 detects the calling clock from the receiver and outputs it to the control IC 62 for control.
The calling address is determined by counting by the counter provided in the IC62. The calling address obtained as the count value of this counter is compared with the sensor address set by the address setting circuit 64, and if they match each other, the calling is discriminated and the control signal a is output to the timing pulse generating circuit 68. . Upon receiving this control signal a, the timing pulse generation circuit 68 drives the LED drive circuit 48 to drive the light emitting element 34 to emit light. At the same time, a control signal is applied to the sample hold circuit 54, and the light receiving signal voltage from the amplifier circuit 52 based on the light receiving output of the light receiving element 36 is sampled and held in synchronization with the light emission drive timing of the light emitting element 34. On the other hand, the control IC 62 is a timing pulse generation circuit at substantially the same timing as the control signal a.
The control signal b is output to 70, and the timing pulse generation circuit 70
Is an amplifier circuit 52 and a sample hold circuit 5 on the circuit section 100 side.
4, analog output control circuit 56 and on-off output control circuit 5
Supply the operating power to 8 and activate it. As a result, on the circuit section 100 side, the smoke density is detected by the light emission drive synchronized with the discrimination of the calling address, and the analog output and the on / off output are controlled based on the sampling result of the light receiving signal voltage according to the smoke density.

Moreover, the control IC 62 determines the state 1 to 9 which is set by the time when the next call clock is obtained after determining the call of itself.
5, for example, as shown in FIG. 5, the control signal c is sent to the voltage-current conversion circuit for normal response at the timing of state 2.
72, the control signal d is output to the voltage-current conversion circuit 76 for type response at the timing of state 3, the control signal e is output to the analog output control circuit 56 at the timing of state 4, and the timing of state 5 is further output. Then, the control signal f is given to the on / off output control circuit 58.

As a result, the voltage / current conversion circuit 72 receives the normal signal in the current mode indicating that the voltage / current conversion circuit 72 is in the normal state on the condition that the abnormality determination output of the abnormality determination circuit 74 is not obtained by the control signal c at the timing of state 2. Send to. Further, the voltage-current conversion circuit 76 receiving the control signal d output at the timing of state 3 sends a signal indicating the type of the sensor to the receiver in the current mode. Further, the analog output control circuit 56 on the side of the circuit section 100 which receives the control signal e in the state 4 is
At that time, the received light signal voltage output from the sample hold circuit 54 is output to the voltage-current conversion circuit 65 and sent to the receiver in the current mode. Further, the output of the control signal f in the state 5 causes the ON / OFF output control circuit 58 on the side of the circuit unit 100 to convert the alarm output voltage into a voltage-current conversion if the received light signal voltage is the second comparison output when it exceeds the threshold value. circuit
Output to 65 and send fire bit signal to receiver in current mode.

Further, the control IC 62 outputs a control signal g to the LED drive circuit 50 on the side of the circuit section 100 every time it discriminates its own calling by the address coincidence, and the indicator lamp 45 is driven to emit light so that the calling is normally performed. indicate.

The abnormality determination circuit 74 provided on the circuit unit 200 side is
When the power supply voltage on the 00 side and the light emission drive of the light emitting element 34 are normally obtained, and the timing pulse from the timing pulse generation circuit 70 is obtained, a normal determination output is generated, and if either one or both are abnormal, The normal response by the voltage-current conversion circuit 72 is released, and the reception side is notified of the occurrence of the sensor abnormality.

In the sensor circuit shown in FIG. 4, the circuit section 10
By dividing into 0 and 200, the terminals 1 to 11 are electrically connected by the connector 18 as indicated by the circled terminal numbers of the circuit boundary line indicated by the one-dot chain line. In this embodiment, as shown in FIG.
Since there are six connectors, two connectors 18 are used to connect the printer boards 14 and 16 on which the sensor circuit of FIG. 4 is mounted.

In the above embodiment, the scattered light type smoke detecting section is taken as an example of the fire detecting section 10, but the present invention is not limited to this, and the ionizing type smoke detecting section, the thermal type smoke detecting section, etc. are appropriately used. It can be applied as it is for each sensor.

In addition, as the sensor circuit mounted on the printed circuit boards 14 and 16 that are built into the circuit housing portion 12 by the connector 18 in a two-layered manner, a sensor circuit having a transmission control function with the receiver is taken as an example. However, it can be applied as it is by dividing the circuit into two parts for mounting an appropriate sensor circuit.

In the above embodiment, the two printed boards 14 and 16 are electrically connected to each other vertically by stacking the printed wiring boards 14 and 16 with the connector 18 interposed therebetween. Of course, it is also possible to stack three or four substrates and an appropriate number of substrates if necessary.

[Effects of the Invention] As described above, according to the present invention, it is possible to incorporate two printed circuit boards in a stacked state with a connector interposed therebetween. Even if the area becomes narrower, the circuit mounting area can be doubled compared to the case where one conventional printed circuit board is incorporated. For example, it is an analog type sensor circuit equipped with a transmission control circuit. However, it can be installed in the circuit compartment with a sufficient margin.

In addition, since two printed circuit boards can be electrically and mechanically connected and fixed by soldering with a connector provided between them, and a support structure such as a screw is not separately required, the process of mounting electrical components on the printed circuit board is hierarchical. It is possible to realize a built-in structure, and it is possible to reduce the cost in terms of production efficiency.

Furthermore, in a stacked structure in which two printed circuit boards are electrically and mechanically connected with a connector interposed therebetween,
The circuit components can be protected by mounting the circuit components such as chip components on the inner surfaces of the printed boards facing each other.

[Brief description of drawings]

FIG. 1 is a structural view of an embodiment of a board-embedded structure according to the present invention; FIG. 2 is a structural view of an embodiment of a connector used in the present invention; FIG. 3 is an exploded view of an assembled structure of the present invention; Is a sensor circuit diagram implemented by the sensor structure of the present invention; FIG. 5 is a time chart showing transmission control of the sensor circuit of FIG. In the figure, 10: Fire detection part 12: Circuit housing part 14: First printed circuit board 16: Second printed circuit board 18: Connector 20: Connector body 22: Connector pin for electrical connection 24: Connector pin for supporting and fixing 26: Contact pin 28: Outer cover 30: Smoke detection space 32: Smoke inlet 34: Light emitting element 36: Light receiving element 38: Lid 40: Chip part 42: Address setting switch 44: Diode bridge 45: Indicator light 46, 78: Fixed Voltage circuit 48, 50: LED drive circuit 52: Amplification circuit 54: Sample hold circuit 56: Analog output circuit 58: ON / OFF output circuit 60: Clock detection circuit 62: Control IC 64: Address setting circuit 65, 72, 76: Voltage / current Conversion circuit 66: Reset circuit 68, 70: Timing pulse generation circuit 74: Abnormality judgment circuit 80: Reference clock generation circuit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masao Shibata 2-10-43 Kamiosaki, Shinagawa-ku, Tokyo Hochiki Co., Ltd. (56) References JP-A-2-240529 (JP, A) Sanaihei 3 -82484 (JP, U) Actual opening 57-14975 (JP, U) Actual opening 64-23884 (JP, U) Actual opening 62-165674 (JP, U)

Claims (2)

(57) [Claims] 1. A sensor having a structure in which a printed circuit board on which a detector circuit is mounted is incorporated into a circuit housing formed behind a fire detection unit protected by a cover unit, wherein the detector circuit is a first circuit. A printed circuit board and a second printed circuit board are divided, and a chip component is mounted on at least one surface of the first printed circuit board. The two printed circuit boards penetrate through an insulating body and are used for a plurality of upper and lower electrical connections. A connector in which a first connector pin and a second connector pin for supporting and fixing are protruded, and a contact pin portion extending in a lateral direction is formed at a tip of the first connector pin protruding below the insulating body. The contact pin portion side is mounted on one surface of the first printed circuit board, the second printed circuit board is superposed on the second printed circuit board, and the second connector pin is provided in the first and second printed circuit boards. Fit in The first and second printed circuit boards are positioned and supported and fixed, and furthermore, the first connector pins are electrically connected to the first and second printed circuit boards by soldering, and at the same time mechanically supported and fixed. A structure for incorporating a sensor into a substrate, characterized in that the sensor is incorporated in the circuit housing portion in a state. 2. The sensor-embedded board structure according to claim 1, wherein circuit parts such as chip parts are mounted on opposite surfaces of the first and second printed boards.