JP4115356B2 - Wiring board fixing structure - Google Patents

Description

  The wiring board of an electronic device whose housing is made of resin is usually securely screwed into the tap hole of the housing or engaged and fixed to the wiring board fixing connector provided in the housing. As for the connection with a display device or the like provided in the housing, a technique for simply and reliably connecting to a pin extending to the housing via the display device using a connector. Has been developed.

  However, in cases where it is necessary to reliably transfer the input / output of the wiring board to and from the outside of the housing, such as alarm devices used in security systems, gas leak alarm systems, etc., while ensuring a more reliable electrical connection, It is desired to make a more reliable connection by soldering the wiring board and the pin so that a connection failure or the like does not easily occur even with respect to vibration, impact, or the like.

  According to the present invention, a wiring board is fixed by soldering to a metal pin erected from a thermoplastic resin casing, and between the wiring board and the outside of the casing via the pin. The present invention relates to a circuit board fixing structure that enables signal transmission.

  As such a fixing structure of the wiring board, a structure in which the wiring board and the pin are directly soldered to be electrically connected to a printed wiring or the like provided on the wiring board and fixed in position is implemented.

However, heat is transmitted to the wiring board and the housing through the pins by soldering work, causing heat distortion or the like in the wiring board, resulting in a decrease in strength, or the housing being deformed by heat. There was a fear. When the strength of the wiring board is reduced by heat, there is a risk of causing wiring failure, leading to a decrease in the reliability of the alarm device or the like. On the other hand, when the housing is thermally deformed, even if the heat deformation is not a problem in appearance, the standing posture of the pin may change, and the strength of the soldering fixing structure may be reduced. This leads to a decrease in the reliability of the connection, and also leads to a decrease in the reliability of alarm devices.
In addition, soldering must be performed when the wiring board is attached, and there is also a problem that solder tends to cause wiring defects due to soldering failure in which solder flows out during operation or solder adheres to the wiring board. .
In addition, according to such a fixing structure, vibration, impact, etc. received by the housing are directly transmitted to the soldering portion, so that the soldering strength may be reduced by vibration, impact, etc.

  Therefore, a connector connected by wiring with a lead wire is connected to the pin, the connector and the pin are soldered to fix the wiring board to the housing, and the pin is attached to the wiring board. An arrangement is made so that the circuit can be electrically connected to the provided circuit (cannot be confirmed as prior art literature).

  When connected in this way, the pins do not have to be directly connected to the wiring board, and by forming the conductor sufficiently long, heat is less likely to be transmitted to the wiring board through the conductor during the soldering operation, The problem of heat distortion and the like occurring on the wiring board is reduced. Further, since the pins do not have to be directly fixed to the wiring board, vibrations, impacts, etc. received by the casing are transmitted to the wiring board via the conductive wires, and the strength of the soldered portion is also reduced. It becomes difficult to get up. However, the possibility of thermal deformation of the housing due to heat transfer from the pin to the housing is not eliminated, and the lead wire is used to solder the connector of a new wire by sewing the gap where the wire is routed. There is a problem that the working wire is obstructed and workability is lowered. Then, since it takes time for soldering, the amount of heat transferred to the housing tends to increase, so that only a skilled person who can quickly complete the soldering operation can do so. Connected. As the workability decreases, the problem of poor soldering is likely to occur.

  Therefore, a connection fitting that can be deformed so as to come into contact with the pin in a state in which the wiring board is attached to the housing is electrically connected to the wiring portion of the wiring board and installed from the wiring board, and separated from the wiring board. It has been implemented so that it can be deformed so as to be contacted at the position where it is formed, and a soldering part is formed at the contact part of the pin with the connection fitting so that it can be soldered (confirmed as prior art literature) Can not).

According to such a configuration, transmission of thermal strain to the wiring board is mitigated, and, like the conductive wire, the connection fitting mitigates transmission of vibration, impact, etc. to the wiring board, thereby reducing thermal strain and soldering strength. The problem is reduced. In addition, compared to the case of using a conductive wire, the connection fitting can easily maintain the standing posture, and the problems related to the deterioration of workability can be reduced.
However, there is still room for improvement in the workability of holding and soldering the pins in a state of being aligned with the connection fittings, and heat transfer to the housing by the soldering work between the connection fittings and the pins is not possible. It remains a problem that cannot be avoided. Therefore, there is a possibility that the soldering strength may be lowered based on a subtle change in the standing posture of the pin, and the problem that soldering failure is likely to occur due to such a situation has not been solved. .

  Therefore, in view of the above situation, the object of the present invention is to reliably perform the wiring to the outside and the fixing of the wiring board to the housing, and heat is applied to the wiring board and the housing during the soldering. It is an object of the present invention to provide a wiring board fixing structure that is difficult to be transmitted, is easy to solder, does not cause poor soldering, and does not easily reduce soldering strength.

  The wiring board fixing structure according to the present invention is characterized in that the wiring board is fixed by soldering to a metal pin erected from a thermoplastic resin casing, and the wiring is connected via the pin. In order to enable transmission of signals between the board and the outside of the housing, with the wiring board attached to the housing, a connection fitting that forms a soldering portion surrounding the periphery of the pin, The soldering part is constructed so as to be separated from the wiring board and electrically connected to the wiring part of the wiring board.

  In other words, since the wiring board is fixed to the pins by soldering, the wiring board is fixed to the housing, and at the same time, the transmission of input / output signals of the wiring board is reliably transmitted to the outside of the housing. When necessary, it is possible to secure a more reliable electrical connection, which is strong against vibrations, shocks, and the like, and can be easily connected without causing a connection failure.

Further, since the connection fitting forms a soldering portion surrounding the periphery of the pin in a state where the wiring board is attached to the casing, the pin is attached when the wiring board is attached to the casing. And held in a state surrounded by the connection fitting. Therefore, even if heat is transferred from the pin to the housing and the housing is easily deformed, the pin is held by the connection fitting, so that the standing posture is hardly changed and stabilized. . For this reason, the strength of the soldering fixing structure and the reliability of the electrical connection are hardly lowered, and the reliability of the alarm device and the like is improved.
In this state, since the soldering portion is formed so as to surround the peripheral portion of the pin, the peripheral portion of the pin can be soldered to the soldering portion of the connection fitting while the pin is securely held. Easy to work and easy to solder. At this time, when the heat associated with the soldering is transmitted to the connection fitting, the soldering portion is provided away from the wiring board. It is possible to form a state in which high heat is hardly transmitted to the wiring board due to heat dissipation. For this reason, the wiring board is subject to thermal distortion, and it is difficult to cause a problem that the strength is lowered, it is difficult to cause the strength reduction of the soldering fixing structure and the reliability of the electrical connection, and the reliability of the alarm device is improved. Connected.

  In the above-described configuration, it is preferable that the connection fitting has a leg portion formed by bending from a plate member, and the leg portion is configured to be erected and fixed to the wiring board.

  According to such a configuration, it is possible to easily form a configuration in which the leg portion is extended from the portion to be the soldered portion by bending the plate member, and by fixing the leg portion to the wiring board, The soldering portion can be held in a state of being separated from the wiring board, and the pin can be easily positioned to enter the soldering portion. Further, by fixing the leg portion to the wiring board while being electrically connected, it is possible to transmit a signal from the wiring of the wiring board to the outside via a connection fitting and a pin. Therefore, the wiring to the outside and the fixing of the wiring board to the housing can be reliably performed with a simple configuration.

  The state in which the soldering portion according to the present invention surrounds the periphery of the pin is a state in which the wiring board is attached to the housing, and the soldering portion can be tilted in any direction. The structure which can suppress the inclination deformation | transformation of the said pin by contact with the said pin. In other words, for example, the plate member is provided with a hole through which the pin is inserted, or the plate member is provided with a notch for receiving the pin with ease and difficulty in detachment. It refers to a state where it can be held in a posture, and can take various forms. In the above-described configuration, it is preferable that a hole portion through which the pin is inserted is provided in the plate member, and that the peripheral portion of the hole portion of the plate member is recessed.

  If the hole is provided, the pin is inserted into the hole, and the peripheral edge of the hole is formed in the soldering portion, so that the pin can be easily soldered to the connection fitting from any direction. Since the edge portion of the hole portion reliably resists the inclined deformation of the pin, the posture can be reliably held. In addition, by forming a recess in the periphery of the hole, a solder pool is formed to store the melted solder in the recess and connect it between the pin and the soldering part when soldering. It is possible to prevent the solder from flowing down to the wiring board while ensuring a large contact area between the solder pool and the pin and the soldering portion, so that the soldering operation can be performed more reliably and easily. Thus, it is possible to further suppress the occurrence of poor soldering.

  Moreover, since the cross-sectional shape of the pin may be distinguished depending on its function, it is preferable that the hole has an edge along the outer shape of a plurality of types of pins having different cross-sectional shapes.

  By configuring in this way, even if a common connection fitting is used in various parts without using different hole-shaped connection fittings for each part of the wiring board, the pins used in that part The hole peripheral part which accept | performed correspondingly and penetrated the pin can be used as a soldering part, and the versatility can be given to the said metal fitting.

  In addition, it is preferable to form a certain amount of gap between the hole and the pin, so that the attachment work for attaching the wiring board to the housing can be performed quickly. At this time, in the above-described configuration, it is preferable that a temporary fixing mechanism for temporarily fixing the connection fitting and the pin is provided in a state where the wiring board is attached to the housing.

In other words, the gap plays a role of absorbing an assembly accuracy error between the housing, the pin, and the wiring board, but allows the pin to be inclined and deformed by the size of the gap. However, if the temporary fixing mechanism is provided, tilt deformation of the pin can be suppressed by the temporary fixing mechanism, and even if heat is transmitted to the housing, stress is transmitted to the housing through the pin. Thus, the deformation of the housing can be suppressed to a very low level.

  Therefore, according to the configuration of the present invention, it is possible to fix and electrically connect the wiring board with good workability and surely even for a gas alarm device or the like that requires particularly high reliability in the fixing structure of the wiring board. Can be made compatible.

The wiring board fixing structure of the present invention will be described by taking a gas alarm as an example.
As shown in FIGS. 1 to 6, the wiring board fixing structure of the present invention is configured such that the wiring board 3 is attached to the casing 1 with respect to the metal pins 2 erected from the casing 1 made of thermoplastic resin. In the attached state, the connection fitting 4 that surrounds the peripheral portion of the pin 2 and forms the soldering portion 4a is erected so that the soldering portion 4a is separated from the wiring board 3 and is electrically connected to the wiring portion 31. The wiring board 3 is soldered between the pin 2 and the soldering portion 4a.

  Although the said form is shown more concretely below, this invention is not limited to the following structures.

  As shown in FIG. 1, the casing 1 of the gas alarm device has a wiring board 3 attached to a lower casing 1a made of resin while being positioned in a plane direction, fixed by soldering, and further, an upper casing made of resin. The body 1b is attached, the wiring board 3 is sandwiched between the upper and lower casings 1a and 1b, and the upper casing 1b and the lower casing 1a are screwed together to fix the wiring board 3 The positioning is performed in the thickness direction.

  As shown in FIG. 1, the lower casing 1a is provided with a pair of AC power input pins 21 and a fixing hook / signal output pin 22, and one end sides 21a and 22a are respectively connected to the casing 1. While standing up in the internal direction, the other end sides 21 b and 22 b are set up so as to be connectable to the outside of the housing 1. The AC power input pin 21 has a circular cross section, and the fixing hook / signal output pin 22 has a square cross section for easy identification.

  As shown in FIGS. 1 and 2, the wiring board 3 has various circuit elements 5 such as a sensor unit provided with a gas detection element and a light emitting diode for light emission of an alarm lamp, and is connected by a printed wiring. An alarm speaker 6 fixed to the upper housing 1b is connected by a conducting wire 61.

  The wiring board 3 is provided with a pin insertion hole 32 at a position corresponding to the pin 2, and a wiring part 31 to be connected to the pin 2 inserted through the insertion hole 32 in the vicinity of the peripheral part of the insertion hole. The connection fitting 4 is erected from the wiring part 31 and is installed on the upper side of the insertion hole 32.

As shown in FIGS. 3 to 6, the connection fitting 4 is formed in a bowl shape in which a plate member is bent to provide a pair of leg portions 42, 42 on a flat plate portion 41. A hole 43 is provided in the base 41 to receive the pin 2.
As shown in FIGS. 2 and 4, a fixing portion 42a is provided at the distal end of the leg portion 42. The fixing portion 42a is inserted into and fixed to the wiring board 3 and can be soldered to be connected to the printed wiring. In addition, the peripheral portion of the hole portion 43 of the base portion 41 is recessed and formed with a solder storage portion 43a. The base portion 41 forms a soldering portion 4a between the solder storage portion 43a and the pin in a state of being separated from the wiring board 3 with the connection fitting 4 being connected to the wiring board 3 (FIG. 5). , 6).
The hole portion 43 includes a square edge portion 43b that fits into the square pin and a circular edge portion 43c that fits into a circular pin, and can be fitted and fixed to any pin shape. As a shape.

When assembling the gas alarm device, the circuit element 5 and the connection fitting 4 are soldered to the printed wiring in advance in the lower casing 1a (see FIG. 1B) in which the pins 2 are previously planted. The attached wiring board 3 is positioned and attached so that each pin 2 is inserted into each insertion hole 32 of the wiring board 3. In this state, the pin 2 is placed in the hole 43 of the connection fitting 4 so as to be engaged (see FIG. 4).
Next, the connection fitting 4 and the pin 2 are soldered at the soldering portion 4a. As a result, the wiring board 3 is fixed to the lower housing 1a via the pins 2 and is electrically connected to the pins 2 so that signals can be transmitted between the wiring board 3 and the outside. The wiring board fixing structure of the present invention can be realized (see FIGS. 2, 5, and 6).
Further, the upper housing 1b is assembled to the lower housing 1a and fixed with screws to be used as the alarm device A.
The obtained alarm device A is attached to a ceiling provided on a ceiling or the like via an adapter B, and the fixing hook / signal output pin 22 is engaged with and fixed to the adapter B. It is electrically connected to the AC power input pin 21 so that external output is possible and power input is possible (see FIG. 7).

The connection fitting can also be configured as shown in FIG.
Specifically, the connection fitting 4 is provided with the hole 43 in the shape of a long hole and is easily formed when the pin 2 is inserted. Furthermore, a part from the base part 41 to the leg part 42 of the connection fitting 4 is cut, and a tongue piece 44 that can be folded back at the uncut portion of the base part 41 is provided, and the wiring board 3 is attached to the lower housing 1b. In the attached state, the pin inserted into the hole 43 is clamped by the plastic deformation of the folded tongue piece 44 to constitute a temporary fixing mechanism capable of temporarily holding. When the pin 41 is temporarily fixed by the temporary fixing mechanism and the base portion 41 of the connection fitting 4 is used as the soldering portion 4a and soldering is performed, the soldering can be reliably performed with good workability.

  In addition to the provision of the tongue piece 44 on the connection fitting 4 as the temporary fastening mechanism, a member other than the connection fitting may be provided to make provisional fastening easy. Etc. can be provided for easy temporary fixing. Further, the tongue piece 44 can be temporarily fixed by being plastically deformed so as to hold the pin 2, but a configuration in which the tongue piece 44 is held by a connector having spring elasticity can also be adopted. Various known techniques can be applied to such a configuration.

  Further, in order to construct the connection fitting 4 on the upper side of the insertion hole 32, the connection fitting 4 may be provided with only one leg portion or more.

  Further, instead of the hole 43 provided in the connection fitting 4, an edge portion along the pin is formed by a notch provided in the connection fitting 4, and a soldering portion 4 a is provided between the edge portion and the pin 2. It can also be set as the structure to form.

  According to the above-mentioned wiring board fixing structure, when it is necessary to reliably transmit the input / output of the wiring board 3 to / from the outside of the housing 1, such as an alarm device used in a security system, a gas leak alarm system, or the like. Even in such a case, it is possible to secure a more reliable electrical connection and to apply to the manufacture of a highly reliable device that does not easily cause a connection failure or the like against vibration, impact, or the like.

Schematic diagram of alarm Perspective view showing relationship between wiring board and housing Perspective view of connecting bracket A plan view showing a state in which a pin is inserted into the connection fitting Longitudinal front view of the wiring board fixing structure of the present invention Longitudinal side view of the wiring board fixing structure of the present invention Diagram showing the fixing structure of the alarm The figure which shows the form of the connection metal fitting in Example 2

Explanation of symbols

1 Housing 2 Pin 3 Wiring board 4 Connection bracket 4a Soldering part

Claims (5)

A wiring board is fixed by soldering to a metal pin erected from a thermoplastic resin casing, and signals are transmitted between the wiring board and the outside of the casing through the pin. A wiring board fixing structure that enables
In the state where the wiring board is attached to the housing, a connection fitting that surrounds the peripheral portion of the pin to form a soldering portion is erected so that the soldering portion is separated from the wiring board. The fixing structure of the wiring board which is electrically connected to the wiring part.   The wiring board fixing structure according to claim 1, wherein the connection fitting has a leg portion formed by bending from a board member, and the leg portion is configured to be erected and fixed to the wiring board.   The fixing structure for a wiring board according to claim 2, wherein a hole portion through which the pin is inserted is provided in the plate member, and a peripheral portion of the hole portion of the plate member is formed to be recessed.   The wiring board fixing structure according to claim 3, wherein the hole has an edge along the outer shape of a plurality of types of pins having different cross-sectional shapes.   The fixing structure of the wiring board as described in any one of Claims 1-4 which provided the temporary fixing mechanism which temporarily fixes the said connection metal fitting and the said pin in the state which attached the said wiring board to the housing | casing.

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