JP4974601B2 - Fire alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire alarm apparatus which prevents load addition to a connection part of a power source cord when pulling force is applied to the power source cord, without needing any special material. <P>SOLUTION: In the fire alarm apparatus in which the connection part 51a of the power source cord 50 is fixed to a power source circuit board 40 disposed within a case composed of a main body 3 and a cover, a cord inserting hole 32 is opened in the main body 3, and a regulating rib 33 is erected at the inner surface 3a side of the main body 3, while a power source cord 50 fixed to the power source circuit board 40 is extended to the front surface 3b side of the main body 3 via the cord inserting hole 32 after detouring around the regulating rib 33. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a fire alarm device, and more particularly to a fire alarm device having a structure for preventing a tensile force from being applied to a connecting portion of a power cord.

  2. Description of the Related Art Conventionally, in a fire alarm device that is supplied with power from an AC power source that is a commercial power source, an AC power cord is drawn into a housing through a cord insertion hole and fixed to a power circuit board (patent) Reference 1). Although the AC power cord drawn into the housing is fixed to the power circuit board by soldering, the soldered portion may be removed by pulling the AC power cord, etc. A bushing member is press-fitted so as to cover the AC power cord in a gap between the AC power cord and the AC power cord so that a tensile force applied to the power cord is not applied to the soldered portion.

JP-A-10-124769

  However, the conventional configuration requires a bushing member, and there is a problem that the assemblability is not excellent and the cost is high.

  The present invention has been made in view of the above points, and a fire capable of preventing a load from being applied to the connection portion of the power cord when a tensile force is applied to the power cord without requiring a special member. Provide an alarm.

A fire alarm device according to the present invention is a fire alarm device in which a connection portion of a power cord is fixed to a power circuit board disposed in a housing. The housing includes a main body in which a cord insertion hole is formed and a cover. The body is provided with a regulating rib on the inner surface side of the cord insertion hole forming surface, and is attached to the mounting surface in a state where the regulating rib forming surface side of the body is covered with a cover. On the side, a water drop intrusion prevention rib is erected around the cord insertion hole, and after the power cord fixed to the power circuit board bypasses the regulation rib, it bends to the cover side on the inner surface side of the main body And then pulled out to the surface of the housing through the cord insertion hole.

Also, fire alarm according to the present invention, regulation ribs erected on the body so as to extend to cover the most recent, even the power cord is pushed inwardly from the surface side of the housing, the power cord restricting ribs It keeps the shape that detours.

Also, fire alarm according to the present invention, regulation ribs erected on the body so as to extend toward the cover, also wire arranging ribs disposed opposite spaced regulating rib, and regulating rib The power cord is straightened by sandwiching the power cord between the straightening ribs and drawn out from the cord insertion hole to the surface side of the housing.

A fire alarm device according to the present invention is a fire alarm device in which a connection portion of a power cord is fixed to a power circuit board disposed in a housing. The housing includes a main body in which a cord insertion hole is formed and a cover. The body is provided with a regulating rib on the inner surface side of the cord insertion hole forming surface, and is attached to the mounting surface in a state where the regulating rib forming surface side of the body is covered with a cover. On the side, a water drop intrusion prevention rib is erected around the cord insertion hole, and after the power cord fixed to the power circuit board bypasses the regulation rib, it bends to the cover side on the inner surface side of the main body And then pulled out to the surface of the housing through the cord insertion hole, it is possible to prevent the tensile force from being transmitted to the connecting portion when a tensile force is applied to the power cord. In addition, since the power cord forms a bent part that bends to the cover side on the inner surface side of the main body before being pulled out from the cord insertion hole, even if water droplets enter the attachment surface side of the main body, It is possible to prevent the water droplets from reaching the connection portion by suitably operating the prevention rib and the bent portion of the power cord.

Also, fire alarm according to the present invention, regulation ribs erected on the body so as to extend to cover the most recent, even the power cord is pushed inwardly from the surface side of the housing, the power cord restricting ribs Since the shape that circumvents this is maintained, it is possible to always prevent a tensile force from being applied to the connecting portion between the power cord and the power circuit board.

Also, fire alarm according to the present invention, regulation ribs erected on the body so as to extend toward the cover, also wire arranging ribs disposed opposite spaced regulating rib, and regulating rib Since the power cord is lined by pinching the power cord between the wire-shaping ribs and pulled out from the cord insertion hole to the front side of the housing, the power cord interferes with the assembly of the main unit and cover. Can be prevented.

  1a is a front view of the fire alarm, FIG. 1b is a cross-sectional view taken along line AA in FIG. 1a, FIG. 2 is a rear view of the fire alarm housing 2, and FIG. 4 is a plan view showing a state in which components are arranged in FIG. 3, FIG. 5 is a perspective view showing the connection surface 3a side (inner surface side) with the cover 4 of the main body 3, and FIG. 6 is FIG. It is a perspective view which shows the state which has arrange | positioned components.

  The fire alarm device of the present embodiment includes a circular base 1 installed on a ceiling or a wall surface, and a circular fire alarm housing 2 (hereinafter referred to as “twist lock lock”) formed so that the back side can be twist-lock fitted to the base 1. The housing 2). The housing 2 includes a main body 3 and a cover 4, and is attached to the base 1 serving as an attachment surface in a state where one surface (an inner surface 3 a described later) of the main body 3 is covered with the cover 4. It has become.

  As shown in FIG. 3, the cover 4 is fitted with four screw holes 4 a for screwing to the main body 3 on the inner surface side thereof, and two protrusions 3 c described later provided in the main body 3. A groove 4b is provided. On the inner surface side of the cover 4 having such a configuration, a printed circuit board 10 provided with a dark box (not shown) for smoke detection on the front surface side as shown in FIG. 4 and a piezoelectric vibration plate 20 for a buzzer are placed. The printed circuit board 10 is electrically connected to a power circuit board 40 (described later) by a connector (not shown).

  As shown in FIG. 5, the main body 3 is provided with a base 31 for attaching the power circuit board 40 and a cord insertion hole 32. Further, on the inner surface 3a side of the main body 3 (the inner surface side of the formation surface of the cord insertion hole 32), a substantially flat regulation rib 33 is erected. The restriction rib 33 is provided between the cord insertion hole 32 and the connection portion (connection portion 51a) of the AC power cord 50 to the power circuit board 40 (FIG. 6). Further, the main body 3 is further provided with a substantially flat plate-shaped rib 34 so as to face the regulating rib 33 with a space therebetween so as to sandwich the cord insertion hole 32. Further, as shown in FIG. 2, a water droplet intrusion prevention rib 32 a protrudes around the cord insertion hole 32 on the surface 3 b of the main body 3.

  When assembling the power supply circuit board 40 to the main body 3 configured as described above, as shown in FIG. 6, first, the power supply circuit board 40 to which the AC power cord 50 is soldered is screwed to the base 31. Then, the AC power cord 50 is curved by bypassing the side surface of the regulating rib 33 in the circumferential direction, and the surface of the main body 3 is passed through the cord insertion hole 32 while adjusting the line between the regulating rib 33 and the adjusting rib 34. Pull it out to the 3b side. As described above, when the AC power cord 50 is subjected to a pulling force by bypassing the regulation rib 33 instead of linearly guiding the AC power cord 50 to the cord insertion hole 32, the pulling force is applied to the AC power cord 50. Can be received by the side end portion 31a of the regulating rib 33 and applied to the connection portion 51a of the AC power cord 50 to the power circuit board 40.

  The pulling force on the AC power cord 50 may be applied in a direction perpendicular to the main body 3 or may be applied in the surface direction of the main body 3. With respect to the pulling force in the direction perpendicular to the main body 3, the side end 31 a of the regulating rib 33 receives the force, and against the pulling force in the plane direction of the main body 3, the side end of the regulating rib 33. Both the 31a and the inner peripheral surface of the cord insertion hole 32 receive the force, and a tensile force is applied to the connection portion (connection portion 51a) with the power circuit board 40 regardless of the direction from which the force is pulled. Can be blocked.

  Moreover, the regulation rib 33 provided in the main body 3 is erected so as to extend up to the cover 4 (FIG. 1 b). Thereby, even if the force which pushes inward from the surface 3b side of the housing | casing 2 is added with respect to AC power cord 50, AC power cord 50 can be maintained in the shape which detours the side surface of the regulation rib 33. That is, conversely, if the height to the cover 4 is low, there is a possibility that when the pushing force is applied to the AC power cord 50, the regulating rib 33 is not bypassed. If a tensile force is applied in this state, a tensile force may be applied to the connection portion 51a of the AC power cord 50 with the power circuit board 40. However, in this example, since the restriction rib 33 extends to the position close to the cover 4 as described above, this can be prevented.

  Further, the straightening rib 34 is also erected so as to extend up to the vicinity of the cover 4 similarly to the regulating rib 33 (FIG. 1b). As a result, the AC power cord 50 can always be accommodated in the space formed by the regulating rib 33, the wire-regulating rib 34, and the inner surface 3a of the main body 3. As a result, if a pressing force is applied to the AC power cord 50, the AC power cord 50 is detached from between the regulating rib 33 and the rectifying rib 34, and the AC power cord 50 is bent toward the screw insertion hole 3d. It is possible to prevent the fastening from becoming impossible.

  Here, the details of the positional relationship between the inner surface 3a of the main body 3 and the AC power cord 50 will be described. The AC power cord 50 is soldered to the surface facing the main body 3 of the power circuit board 40 as shown in FIG. After being connected, it contacts the inner surface 3a of the main body 3 from the connecting portion 51a upward (toward the ceiling), and passes between the regulating rib 33 and the wire-regulating rib 34, and the AC power cord 50 After being bent downward by the tensile force to form the bent portion 51b, the bent portion 51b is directed upward toward the cord insertion hole 32 and pulled out from the cord insertion hole 32.

By drawing the AC power cord 50 in this way, the following effects are obtained from the viewpoint of preventing water droplets from entering. That is, first, water is prevented from entering from the front surface 3b side to the inner surface 3a side of the main body 3 by the water droplet intrusion prevention rib 32a provided on the front surface 3b side of the main body 3. Even if a water droplet enters through the cord insertion hole 32, the water droplet drops on the contact portion with the bending portion 51b or the regulation rib 33 or the wire-regulating rib 34 of the AC power cord 50. Never reach.
In FIG. 6, the AC power cord 50 is represented by a width smaller than the actual width in order to explain the details of the positional relationship between the inner surface 3 a of the main body 3 and the AC power cord 50. Actually, as shown in FIG. 1 b, the width of the AC power cord 50 is substantially equal to the distance between the regulating rib 33 and the wire-regulating rib 34.

Here, the assembly procedure of the fire alarm configured as described above will be described.
First, on the inner surface of the cover 4, the printed circuit board 10 provided with a smoke detection dark box (not shown) on the surface side and the buzzer piezoelectric diaphragm 20 are placed. Then, the power circuit board 40 is mounted on the main body 3 as described above, and the AC power cord 50 is pulled out from the cord insertion hole 32. Then, the printed circuit board 10 and the power circuit board 40 are electrically connected by a connector (not shown). Then, the cover 4 and the main body 3 are positioned by fitting the protrusion 4 c provided on the peripheral surface of the main body 3 into the groove 4 b provided on the peripheral surface of the cover 4, and four screws 60 are attached to the main body 3. The housing 2 is assembled by screwing and fixing to the screw hole 4a of the cover 4 through the screw insertion hole 3d. Then, the housing 2 is twisted with respect to the base 1 and locked to the base 1.

  As described above, according to the present embodiment, since the AC power cord 50 is pulled out from the cord insertion hole 32 by bypassing the regulating rib 33, it is possible to prevent a tensile force from being transmitted to the connecting portion 51a. In addition, the structure is simple because the restriction rib 33 is simply erected. Further, since the regulation rib 33 is erected on the main body 3 so as to extend to the cover 4, even if the AC power cord 50 is pushed in, the shape around the regulation rib 33 can be maintained, and the connection portion Transmission of the pulling force to 51a can be prevented.

  In addition, since the wire-regulating rib 34 is provided to guide the AC power cord 50 to the cord insertion hole 32 in a state where the AC power cord 50 is aligned with the regulating rib 33, the AC power cord 50 is attached to the cover 4 when the AC power cord 50 is assembled. Can be prevented.

  In addition, since the straightening rib 34 is also erected on the main body 3 so as to extend to the cover 4, if the pushing force is applied to the AC power cord 50, the AC power cord 50 is aligned with the regulating rib 33. It is possible to prevent inconveniences such that the screw rib 3b is bent from the space between the wire rib 34 and bent toward the screw insertion hole 3d, and cannot be screwed.

  Even if water droplets enter the surface 3b of the main body 3, the water droplet intrusion prevention ribs 32a provided on the surface 3b side of the main body 3 and the shape of the AC power cord 50 are suitably acted on. It is possible to prevent water droplets from reaching 51a.

It is a front view of a fire alarm. It is AA arrow sectional drawing of FIG. 1a. It is a rear view of a fire alarm case. It is a top view which shows the inner surface of a cover. It is a top view of the state which has arrange | positioned components in FIG. It is a perspective view which shows the connection surface side with the cover of a main body. It is a perspective view which shows the state which has arrange | positioned components in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Housing | casing 3 Main body 3a Inner surface 3b Surface 3c Protruding part 3d Screw insertion hole 4 Cover 4a Screw hole 4b Groove part 10 Printed circuit board 20 Piezoelectric diaphragm 31 Base 32 Code insertion hole 32a Water droplet intrusion prevention rib 33 Restriction rib 34 Linear Rib 40 Power supply circuit board 50 Power supply cord 51a Connection part 51b Deflection part 60 Screw

Claims (3)

In the fire alarm where the connection part of the power cord is fixed to the power circuit board arranged in the housing,
The housing includes a main body having a code insertion hole and a cover, and a restriction rib is provided on the inner surface side of the formation surface of the code insertion hole, and the restriction rib of the main body is formed. It is attached to a mounting surface in a state where the surface side is covered with the cover, and on the mounting surface side of the main body, a water drop intrusion prevention rib is provided around the cord insertion hole, and the power supply circuit board is provided with the rib. After the fixed power cord bypasses the regulation rib, a bent portion that is bent toward the cover side is formed on the inner surface side of the main body, and then is formed on the surface of the casing through the cord insertion hole. A fire alarm characterized by being pulled out. Shape before Symbol restricting rib is erected on the body so as to extend to the cover nearest, even as the power cord is pushed inwardly from the front side of the housing, said power cord to bypass said regulating rib 2. The fire alarm according to claim 1, wherein the fire alarm is maintained. Before SL restricting rib is erected on the body so as to extend toward the cover, also wire arranging ribs provided spaced and opposed to the regulation rib, and the restricting rib and the wire arranging ribs 2. The fire alarm device according to claim 1, wherein the power cord is drawn out from the cord insertion hole to the surface side of the housing while the power cord is arranged between the power cords.

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