JPH0219310Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an improvement of an automobile light control device that adjusts the brightness of illumination light that illuminates a panel board of a dashboard panel of an automobile.

[Technical background of the invention and its problems]

The first of its kind as a conventional automotive light control device.
The devices shown in FIGS. 3 and 14 are known.

This will be explained below.

1 is a printed circuit board motherboard on which a circuit pattern is printed, and electronic components 2 for an oscillation circuit, a power transistor 3 for a power driver circuit, and a variable resistor 4 for variable switching duty are soldered to the required circuits. .

A lead wire 5 from the motherboard 1 and a shaft 4a of the variable resistor 4 are led out from a case (not shown), and the lead wire 5 is connected to a power source and an illumination lamp. It controls the illuminance of the lighting lamp by varying the duty of oscillation switching.

In this way, conventional automotive light control devices used a variable resistor that was completed as a variable resistor, which resulted in a large case and required a large amount of installation space, which was inconvenient both in terms of cost and cost. It was happening.

[Purpose of invention]

This invention is based on the fact that the power transistor of the power driver circuit generates less heat, or the substrate is made of alumina.
It is formed by applying an insulating film to a ceramic or metal plate, and has a heat dissipation effect and heat resistance, and is mainly used when there is no need to consider heat dissipation from the power transistor.

The present invention aims to eliminate the drawbacks of the conventional automotive light control device mentioned above, and the terminal board, the resistor of the variable resistor, and the power transistor are installed adjacent to the circuit board, and the case is mounted on the circuit board. In addition to being equipped with a sliding terminal for a variable resistor, the outer shell of the connector is made and the connector is formed with the terminal board, eliminating the need for an intermediate connector, and the purpose is to make it possible to realize miniaturization and cost reduction. It is something to do.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Reference numeral 11 denotes a mounting plate for mounting the power transistor 12, and has a terminal 11a at one end, a punching plate 11b at its base, a protruding portion 11c on the opposite side, and a bent heat dissipating fin 11d. is standing up.

13 is formed by forming an insulating film on alumina, ceramic, or metal plate, and has good thermal conductivity.
Or a printed circuit board with characteristics such as heat resistance, or electronic components 15 soldered thereto.
This motherboard has heat resistance.

And on one side of it is a resistance coating 1 of a variable resistor.
4a is installed, and on the other side, a mounting plate 11 is attached so that the motherboard 13 is sandwiched between the punched pieces 11b, and the round 13 of the motherboard 13 is mounted.
The mounting plate 11 is attached by soldering the punched piece 11b to the mounting plate 11a and the through hole 13b of the motherboard 13, and the legs of the power transistor are soldered to the circuit pattern of the motherboard 13.

Reference numeral 16 designates a terminal board, and a punching piece 16b is formed at the base of the terminal board, and the punching piece 16 is sandwiched between the motherboard 13 by the punching piece 16b in the same way as the terminal 11a.
b and the round 13a of the motherboard 13 are soldered, and the round 13a of the motherboard 13 is soldered together with the terminal 11a.
mounted on.

Reference numeral 17 denotes a case made of an insulator such as plastic, and has an outer shell 17a of the connector on the back side, an insertion hole 17c in the partition wall 17b of the outer shell 17a, and a support rail 17d and an insertion hole 17e on the inner surface. Shafts 17f are respectively formed on the upper inner surface into which knobs 14c of variable resistors having sliding terminals 14b can be rotatably inserted.

After inserting this knob 14c into the shaft 17f,
When the motherboard 13 is inserted into the support rail 17d by inserting the terminals 11a and the terminal plate 16 from the insertion holes 17c toward the outer shell 17a, the bulges 11c fit into the insertion holes 17e and the motherboard 1
3 can be attached, and the outer part 17a, the terminal 11a, and the terminal plate 16 form a connector.

When the knob 14c is rotated from the outside, the sliding terminal 14b slides on the resistive coating 14a, and the resistance value can be made variable. Therefore, the duty of self-oscillation switching can be varied, and the illumination intensity can be varied. It is something that can be adjusted.

[Description of other embodiments]

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 8.

In the previous embodiment, the knob 14 was inserted from the side of the case 17.
The illuminance was adjusted by rotating the shaft 27a laterally, but in this embodiment, the shaft 27a is mounted on the upper surface of the upper case 27a.
4d protrudes and is rotated to adjust the illuminance, and a connector is formed on the lower surface of the lower case 27b.

Reference numeral 21 designates a mounting plate for the power transistor 22, and similarly to the mounting plate 11 of the previous embodiment, a terminal 21a, a punched piece 21b, and a heat radiation fin 21c are formed.

Reference numeral 23 designates a motherboard, which is similar to the motherboard 13 of the previous embodiment, and includes a variable resistance resistance coating 24a, a circuit pattern, and electronic components 15 soldered thereto.
Round 23a, through hole 23 for terminal attachment
b is provided.

Then, the mounting plate 21 is attached in the same manner as in the previous embodiment, the legs of the power transistor 22 are soldered to the circuit pattern, and the terminal plate 26 is soldered to the circuit pattern.
is attached to the terminal 21b by soldering the punched piece 26b.

The case 27 that accommodates such a motherboard 23 is formed of an upper case 27a and a lower case 27b, and the upper case 27a has a shaft bearing hole 27c into which a shaft 24d of a rotating piece 24c provided with a sliding terminal 24b is inserted. , an engagement hole 27e is formed that engages with a protrusion 27d of the lower case 27b to be in a closed state.

In addition to the protrusion 27d, the lower case 27b includes:
The outer shell part 27f of the connector, the terminal 21a,
An insertion hole 27g into which the terminal plate 26 is inserted is provided on the lower surface.

The shaft 24 is inserted into the bearing hole 27c of the upper case 27a.
d, and then insert the terminal 21a and the terminal plate 26 into the insertion hole 2.
7g and insert the motherboard 23 into the lower case 27
b, and when the upper case 27a and the lower case 27b are overlapped and the protrusion 27d and the engagement hole 27e are engaged to be in the closed state, the rotary piece 24c of the variable resistor is rotatably supported. , the sliding terminal 24b has a resistive coating 2
The resistance value can be made variable by sliding on 4a.

Therefore, a knob is attached to the shaft 24d, and the illuminance can be adjusted by rotating the knob.

Furthermore, a third embodiment in which the variable resistor is of a sliding type will be explained with reference to FIGS. 9 to 12. This embodiment differs from the second embodiment except for the parts described below. do not have.

A variable resistance coating 24a provided on the motherboard 23 is formed in a linear shape, and a linear guide hole 27h is formed in the upper case 27a.

The operating knob 24e provided with a variable resistance sliding terminal 24b can be inserted into the guide hole 27h and slid linearly along the guide hole 27h, and can adjust the illuminance by changing the resistance value. It is possible.

The present invention is not limited to those shown in the embodiments, and can be modified in various ways, such as providing a connector at a position other than the position described above, or making the case have a shape other than a housing shape.

[Effect of idea]

As mentioned above, the present invention is a device that functions as a variable resistor by installing a variable resistance resistor on a board with electronic components attached, without using a completed variable resistor. Therefore, the volume is reduced compared to a conventional variable resistor using a completed variable resistor, and the circuit can be made denser, and the size can be reduced, and the installation space can be reduced.

Furthermore, since the resistor can have a unique resistance curve, it is also possible to match the operating state and illuminance adjustment.

Furthermore, by providing the connector terminals directly on the board,
Since the connector is formed together with the case, it is no longer necessary to solder the lead wires and further solder the connector to the lead wires as in the conventional case, thereby reducing parts costs and assembly costs.

Moreover, since the connector and variable resistor terminals do not need to be soldered, which was a major factor in reducing reliability in the past, reliability is greatly improved.

In addition, the power transistor of the power driver circuit generates little heat, or the substrate is made of a highly heat-resistant material such as alumina or ceramic, or an insulating film is formed on a metal plate and a circuit pattern is printed on it. This invention is useful when there is no need to pay particular attention to cooling the heat generated by the power transistor due to good conduction or because the electronic components soldered to the board are highly heat resistant. applied, contributes to cost reduction,
It has many features such as being able to improve reliability.

[Brief explanation of drawings]

1 to 4 show the first embodiment of the present invention, FIGS. 5 to 8 show the second embodiment, and FIGS. 9 to 12 show the third embodiment of the invention. Figure, Figure 5, Figure 9
The figure is an exploded perspective view, Figures 2, 6, and 10 are back views of the motherboard, Figures 3 and 4, Figures 7 and 8, and Figures 11 and 12 are the assembled state. FIG. 13 and FIG. 14 are perspective views of a conventional automobile dimmer as seen from opposite sides. 11, 21... Mounting plate, 11a, 21a... Terminal, 12, 22... Power transistor, 13,
23... Motherboard, 14a, 24a... Resistance coating of variable resistance, 14b, 24b... Sliding terminal,
15...Electronic component, 16, 26...Terminal board, 17
... Case, 27a ... Upper case, 27b ... Lower case, 17a, 27f ... Outer part of connector,
17c, 27g...Terminal board insertion holes.

Claims (1)

[Claims for Utility Model Registration] The power transistor and the power transistor control resistor on which the slider of the variable resistor slides, electronic components and terminals are attached to the circuit pattern, and have good thermal conductivity and heat resistance. a substrate; a case for accommodating the sliding terminal of the variable resistor in a slidable manner with the substrate and forming a connector together with the terminal; and a case rotatably or slidably supported by the connector; A variable resistance operator; and a terminal attached to the substrate is a male terminal of a connector.