JP2877749B2 - Small electrical equipment with a built-in printed circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small electric device, and more particularly to a small electric device in which a lead wire such as a power cord is detachably connected to a built-in printed circuit board by a connector.

[0002]

2. Description of the Related Art Small portable electronic devices, such as chargers, can be conveniently used if they are as small as possible. In order to reduce the size of an electric device, it is necessary to densely arrange each electronic component. The electronic components are densely packed by reducing unnecessary space in the case. The components fixed to the printed circuit board can be arranged closely together. However, a detachable connector cannot be easily attached or detached if there are dense components around it, so it is necessary to provide a detachable space around the connector. The space for attachment and detachment becomes a dead space in which no components are arranged, which hinders miniaturization of electric equipment.

[0003]

Therefore, compactness of the case and easy attachment and detachment of the connector are contradictory to each other. For this reason, it is extremely difficult to reduce the outer shape of the case and to design the connector so that the connector can be easily attached and detached.

[0004] Further, in an electric device in which a detachable connector is attached to a printed circuit board and a lead wire such as a power cord is connected to the printed circuit board in the case via the connector, the connector is disconnected when the lead wire is pulled. There is an easy disadvantage. In order to solve this drawback, a rubber bush or the like is inserted between the through hole of the case and the lead wire.
However, it is difficult for the bush to prevent the connector from coming out even if the lead wire is pulled.

In order to prevent the connector from being pulled out by being pulled by the lead wire, a through hole may be provided in the case so that the pulling direction of the connector is perpendicular to the pulling direction of the lead wire. This structure has a feature that even if the lead wire is pulled, the connector is not pulled in the pulling-out direction, so that the connector can be hardly removed. However, in this structure, an excessive force acts on a portion connecting the fixing portion of the connector to the printed circuit board. This is because when the lead wire is pulled, a force acts in a direction in which the fixing portion of the connector is tilted. Therefore, this structure has a disadvantage that the connecting portion between the fixing portion and the printed circuit board is easily damaged or deformed.

[0006] The present invention has been developed with a view to solving such a drawback. An important object of the present invention is to provide a small-sized electric device which has a compact printed circuit board on which the connector can be easily attached / detached and which can be easily attached / detached. Another important object of the present invention is that
An object of the present invention is to provide a small-sized electric device having a built-in printed circuit board that can effectively prevent a connector from being pulled out of the printed circuit board when a lead wire is pulled.

[0007]

SUMMARY OF THE INVENTION A small electric device having a printed circuit board according to the present invention includes a printed circuit board 2 contained in a case 1 and a detachable connector 3 fixed to the printed circuit board 2. The connector 3 includes a fixed portion 3A fixed to the printed circuit board 2 and a detachable portion 3B detachably connected to the fixed portion 3A. Detachable part 3B
Is connected to a lead wire 4 drawn out from a through hole 7 of the case 1 to the outside.

[0008] Furthermore, in the small electric equipment, the detachable portion 3B of the connector 3 is detached from the fixed portion 3A.
The upper and lower cases 1 are attached to the detachable space 5 provided around the
A boss 6 for connecting A and 1B is formed integrally with the case 1.
The boss 6 and the connector 3 are arranged adjacent to each other. When the printed circuit board 2 is removed from the case 1,
The boss 6 is removed, and the removable space 5 is formed. The detachable portion 3B of the connector 3 is detached by using the detachable space 5.

Further, in the small-sized electric device incorporating the printed circuit board of the present invention, in addition to the approach of the connector 3 and the boss 6, the relative positions of the connector 3, the boss 6 and the through hole 7 of the lead wire 4 are unique . It is located at the location. That is, there is a boss 6 between the through hole 7 and the connector 3, and
The lead wire 4 is curved along the boss 6, and when the lead wire 4 is pulled, the lead wire 4 is pressed against the surface of the boss 6.
Then, the frictional resistance is increased, and the boss 6 is configured to prevent the connector 3 from being pulled out.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a small electric device for embodying the technical idea of the present invention, and the present invention does not specify a small electric device incorporating a printed circuit board as follows. .

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members described in the embodiments will be referred to as "claims" and " In the column of “Means of the above”. However, the members described in the claims are not limited to the members of the embodiments.

FIG. 1 is a sectional view of a small electric device, and FIG. 2 shows a printed circuit board 2 built in a case 1. The electrical devices shown in these figures are chargers. However, the present invention does not specify a small electric device including a printed circuit board as a charger. The small electric device can be any electric device in which a connector is fixed to a printed circuit board, a lead wire is connected to the connector, and the lead wire is drawn out of the case.

In the electric apparatus shown in FIG. 1, a printed circuit board 2 is built in a case 1 and fixed. The case 1 is a plastic molded product, and includes an upper case 1A and a lower case 1B.
The upper and lower cases 1A and 1B are connected to each other at the periphery. On the upper surface of the upper case 1A, there is provided a mounting portion 8 for detachably setting the secondary battery 10. In order to mount the secondary battery 10 in a fixed position, the mounting portion 8 has a hook 9 protruding and integrally formed. The hook 9 is the concave portion 1 of the secondary battery 10.
3 and set the secondary battery in place.

The secondary battery 10 set in the mounting section 8 is
The charging is performed by electrically connecting the charging terminal to the contact 11.
In order to connect the contact 11 to the charging terminal, the case 1 has a slit 12 for exposing the contact 11 to the outside of the case 1. The contact 11 is a wire rod that is elastically deformed, protrudes from the slit 12 to the outside of the case 1, and comes into contact with the charging terminal. The contact 11 is connected to a charging circuit fixed to the printed circuit board 2, and charges the secondary battery 10.

On the printed circuit board 2, parts constituting a charging circuit and a connector 3 for connecting a lead wire 4 for supplying power to the charging circuit are fixed by soldering. The connector 3 includes a fixed portion 3A fixed to the printed circuit board 2 and a detachable portion 3B detachably connected to the fixed portion 3A. The lead wire 4 is connected to the attaching / detaching portion 3B, and is electrically connected to the printed circuit board 2 via the fixing portion 3A.

The connector 3 is disposed close to a boss 6 integrally formed with the case 1 as shown in a sectional view of FIG. To arrange the connector 3 in this part,
The printed board 2 shown in the perspective view of FIG. 2 has a boss hole 14 adjacent to the connector 3. Boss hole 14
Inserts the boss 6 of the case 1 and presses and fixes the printed circuit board 2 to the case 1. Printed circuit board 2 in case 1
When the boss 6 is removed, a space is created in a portion where the boss 6 is mounted. This space is referred to as a detachable space 5 where the detachable portion 3B of the connector 3 is detachably attached to the fixed portion 3A.

The printed board 2 shown in FIG. 2 has a transistor 16 and a ferrite core 1 on both sides of the connector 3.
5, a vertical board 17 is provided on the back of the connector 3, the front surface of the connector 3 is a detachable space 5, and a boss 6 of the case 1 is provided here. When the printed circuit board 2 having this structure is not mounted on the case 1, the boss 6
There is a detachable space 5 in the mounting part of the. The space where the boss 6 is located is used as the attachment / detachment space 5 of the connector 3 so that the attachment / detachment portion 3B of the connector 3 can be easily attached to the fixing portion 3A. That is, the attachment / detachment space 5 is used as a space for attaching / detaching the attachment / detachment portion 3B of the connector 3 and a space for disposing the boss 6.

Further, the electric equipment shown in FIG.
The relative positions of the through hole 7, the connector 3, and the boss 6 provided in the boss are arranged at special positions. The through hole 7 of the case 1 is a hole for drawing out the lead wire 4 from the inside of the case 1 to the outside. The boss 6 is provided with the through hole 7 of the case 1 and the connector 3.
It is arranged between. Case 1 where boss 6 is placed here
Guides the lead wire 4 connected to the printed circuit board 2 through the connector 3 along the outer periphery of the boss 6 into the through hole 7 as shown by the chain line in FIG. When the lead wire 4 that is curved along the boss 6 is pulled in the direction of the through hole 7, the lead wire 4 is prevented from being pulled out due to the frictional resistance that comes into contact with the surface of the boss 6. In particular, when the lead wire 4 that is curved along the boss 6 is strongly pulled, the lead wire 4 is strongly pressed against the surface of the boss 6 and the frictional resistance is increased, so that the lead wire 4 cannot be pulled out.

Further, in the small electric apparatus shown in FIGS. 1 and 2, the boss 6 is disposed very close to the connector 3. In the small electric device having this structure, when the lead wire 4 is pulled and the connector 3 is tilted,
Can be prevented from colliding with the boss 6 and tilting.

The printed board 2 is pressed by the boss 6 and fixed at a fixed position of the case 1. The boss 6 has a cylindrical shape whose lower end can be inserted into the boss hole 14, and a rib 6 </ b> A for pressing the upper surface of the printed circuit board 2 is integrally formed along the surface thereof. The cylindrical boss 6 is screwed around a set screw 18 passing through the lower case 1 to connect the upper and lower cases 1A and 1B. The printed circuit board 2 shown in FIG. 1 has a right end portion inserted into a groove 19 provided in the lower case 1 and a left end portion pressed by a boss 6 to be fixed at a fixed position of the case 1 in the figure.

Since the small electric device shown in FIG. 1 is a charger, electronic components constituting a charging circuit are fixed to the printed circuit board 2. The electronic circuit of the printed circuit board 2 includes a lead wire 4
And the electric power input through the connector 3 are converted into a voltage and a current for charging the secondary battery and output to the contact 11.

The contact 11 is mounted on an insulating case 20 of a transformer constituting a charging circuit. The insulating case 20
A plastic case molded so as to receive a transformer (not shown) has a lower part opened, the transformer is inserted, and the terminals of the transformer are soldered to the printed circuit board 2. The insulating case 20 is integrally formed with a contact holding portion 21 for supporting the contact 11 at a fixed position. The contacts 11 are provided on both sides of the insulating case 20. Therefore, the contact holding portions 21 are integrally formed on both sides of the insulating case 20 so as to protrude from the side surfaces thereof. The contact holding portion 21 is formed from an upper portion of the insulating case 20 to a vertical portion so that the contact 11 can protrude from the slit 12 of the case 1 to the outside. The contact holding portion 21 is an L-shaped groove provided on a vertical portion and an upper portion of the insulating case 20 for mounting the L-shaped contact 11.

[0023]

According to the present invention, a small-sized electric device having a printed circuit board therein has a feature that the connector can be easily attached to and detached from the printed circuit board and the whole can be made compact. That is, a small electric device incorporating the printed circuit board of the present invention has a case boss disposed in a detachable space provided around the connector, and the case boss and the connector are disposed adjacent to each other. Because. In a small electric device of this structure, when the printed circuit board is detached from the case, the detachable space is used as a space for attaching and detaching the connector, and when the printed circuit board is fixed to the case, it is used as a space for disposing the boss. . The small-sized electric device incorporating the printed circuit board of the present invention realizes the feature that the detachable space is used for two purposes as described above, the external shape is compact, and the connector can be easily detached.

Further, the small-sized electric device incorporating the printed circuit board of the present invention has a feature that the connector can be effectively prevented from being pulled out from the printed circuit board when the lead wire is pulled. This is because the small electric device incorporating the printed circuit board of the present invention has a boss disposed between the through hole and the connector, and when the lead wire is pulled, the boss prevents the connector from being pulled out.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a small electric device including a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of a printed circuit board of the small electric device shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Case 1A ... Upper case 1B ... Lower case 2 ... Printed circuit board 3 ... Connector 3A ... Fixed part 3B ... Detachable part 4 ... Lead wire 5 ... Detachable space 6 ... Boss 6A ... Rib 7 ... Through-hole 8 ... Mounting part 9 ... Hook 10 ... Rechargeable battery 11 ... Contact 12 ... Slit 13 ... Recess 14 ... Boss hole 15 ... Ferrite core 16 ... Transistor 17 ... Vertical board 18 ... Set screw 19 ... Groove 20 ... Insulating case 21 ... Contact holding part

Claims (1)

(57) [Claims] 1. A printed circuit board (2) built in a case (1).
The fixed part (3A) is fixed to the printed circuit board (2), and is detachably connected to the fixed part (3A).
Lead wire drawn out from through hole (7) in (1)
Connector consisting of a detachable part (3B) to which (4) is connected
In a small electric device incorporating a printed circuit board (2) equipped with (3), a connector (3) was provided around the connector (3) to attach and detach the detachable part (3B) of the connector (3) to the fixed part (3A). Desorption space
At (5) , attach the boss (6) connecting the upper and lower cases (1A) and (1B).
The boss (6) and the connector (3) are arranged adjacent to each other, and the printed circuit board (2) is removed from the case (1). And the connector (3) using the removable space (5) from which the boss (6) has been removed.
(3B), and the relative positions of the through hole (7) of the connector (3), the boss (6) and the lead wire (4) are different from those of the through hole (7) and the connector (3). There is a boss (6) in between, and the lead wire (4) curves along the boss (6)
And it is, when the lead wire (4) is pulled, the lead
The wire (4) is pressed against the surface of the boss (6), increasing the frictional resistance
Become, the boss (6) connector (3) compact electric apparatus the printed circuit board characterized by comprising configured <br/> incorporated to prevent withdrawal of.