JPH09289383A - Circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the waterproofness of a circuit device. SOLUTION: In this circuit device, a resin 22 is filled inside of a case body. At least one of a plurality of cords 24 connected to a circuit board 21 is led out of the case body through a cut-out provided in the case body, and is held by a cord holding member 30 having a cord insertion hole 33. The cord holding member 30 is fitted in the cut-out so as to close the cut-out. Inside of the case body, an end portion of the cord holding member 30 where the cord insertion hole 33 is opened is buried in the resin within the case body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit device having improved waterproofness.

[0002]

2. Description of the Related Art A circuit board on which electronic components are mounted is housed in a box made of, for example, a substantially container-like synthetic resin or metal, and its opening is covered with a lid to seal it. There is a circuit device in which the waterproofness of parts is improved.

In such a circuit device,
At the joint between the lid and the box, a synthetic rubber packing is interposed between the lid and the box to eliminate gaps and prevent water from entering the inside. In addition, a synthetic rubber bushing is also attached to a cord lead-out hole for electrical connection between the outside and the circuit board, which is provided in the lid body or the box body, and a gap between the cord and the hole is provided. It is supposed to be lost.

[0004]

By the way, in the above-mentioned circuit device, the synthetic rubber used as the packing or the bushing (cord holding member) is vulnerable to oil and high heat and is apt to deteriorate. Therefore, if the packing or bushing deteriorates, a gap is created between the lid and the box and between the bushing inside the cord lead-out hole and the cord, and water enters the inside of the circuit device through this gap. There has been a problem that rust or corrosion is caused or a leak is caused in a metal part of an electronic component or a circuit board.

For example, water adhering to the cord travels along the cord into the cord lead-out hole of the bushing, further penetrates into the box of the circuit device along the cord, and finally the cord is connected. It may reach the circuit board that is already in use and cause the above problems.

This is especially true for a circuit device used for an automobile in an environment where the packing and bushing are more likely to be deteriorated because a heat source such as an oil or an engine that emits high heat is present in the immediate vicinity.

[0007]

Therefore, in the circuit device of the present invention, the inside of the case body is filled with resin, and at least one of a plurality of cords connected to the circuit board is passed through a notch provided in the case body. The cord holding member is led out of the body and is held by a cord holding member having a cord insertion hole, and the cord holding member is fitted into the notch to close it, and
Inside the case body, one end of the cord holding member having the cord insertion hole opened is embedded in the resin inside the case body.

Therefore, even if a gap is created between the cord holding member and the lid or box, or between the cord holding member inside the hole for leading out the cord and the cord, the inside of the case body is filled with resin. Moreover, since one end of the cord holding member having the cord insertion hole opened is embedded in the resin inside the case body, the circuit board is not affected by water, and rust and corrosion of the metal part, It is possible to prevent current leakage.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the circuit device according to the present invention will be described below with reference to an embodiment shown in the accompanying drawings.

The circuit device 1 is mainly formed by housing a circuit board on which electronic components are mounted in a case body 2 made of a rectangular box-shaped metal, for example, an aluminum alloy die cast (ADC). Further, the case body 2 includes a container-like box body 3 having a substantially rectangular shape in a planar shape opened toward one side, and a lid body 4 covering the opening of the box body 3. And
From the case body 2, connection codes to be described later are led out at two places.

The circuit device 1 in this embodiment is the circuit device of the present invention applied as a lighting circuit device for a vehicle discharge lamp having a ballast circuit and a starter circuit.

In the following description, the up / down, front / rear, left / right directions will be referred to as the left / right direction, the left / right direction as the front / rear direction, and the up / down direction in FIG. 2 as the up / down direction.

As shown in FIG. 2 and FIG. 3, the box body 3 is formed with a peripheral wall 6 which rises substantially vertically from the peripheral edge of the bottom plate 5 over the entire circumference, and opens upward, and The depth is shallower than the length and the width, that is, the shape of the container is rectangular. A small step 6a facing outward is formed on the upper end surface of the peripheral wall 6 over the entire circumference.

Further, at the four corners of the box body 3, the thickness of the peripheral wall 6 is increased so that screw holes 7a for fixing the lid body 4 to the box body 3 are formed.
Are formed, and boss portions 7, 7, ...
As shown in FIG. 3, a partition wall 8 having the same height as that of the peripheral wall 6 is formed inside the peripheral wall 6 in a substantially L shape from a position on the rear wall of the peripheral wall 6 toward the right side to a position on the front side toward the right side wall. Thus, the inside of the box body 3 is divided into two parts by the partition wall 8, and the starter circuit housing part 9 which is the right rear part and the ballast circuit housing part 10 which is the other part are formed. There is.

As shown in FIGS. 2 and 4, the lid 4 is formed in a substantially plate shape having substantially the same plane shape and size as the bottom plate 5 of the box body 3. Further, as shown in FIG. 4, a substantially U-shaped notch 12 is formed at a position near the front of the right side edge of the main portion 11.

Further, screw insertion holes 13, 13, ... Are formed at the four corners of the lid body 4 corresponding to the positions of the boss portions 7, 7, ... Formed at the four corners of the box body 3, respectively. There is.

The lower surface 11a of the lid 4 has an outer edge portion 1
4 is thicker than other portions of the main portion 11 except for the portion where the notch 12 is formed. Further, the outer edge portion 14 has a sealing groove along the outer edge shape of the lid body 4. 1
5 are formed.

Furthermore, a circular opening 16 is provided at a position closer to the right side from the center of the main portion 11 of the lid 4. In addition, as shown in FIGS. 1 and 2, the upper surface 11b of the main portion 11 surrounds the opening 16 so as to surround the opening 16.
The standing walls 17 and 18 are provided concentrically with each other, and the opening 1
The inner standing wall 17 protruding from the opening edge of the opening 6 has a height slightly higher than the outer standing wall 18 from the upper surface 11b of the main portion 11. The standing wall 17 has 120
Projected toward the center of the opening 16 from three places apart from each other,
Mounting ear piece 19 having screw holes 19a, 19a, 19a,
19 and 19 are formed.

The starter circuit housing 9 and the ballast circuit housing 10 in the case body 2 composed of the box body 3 and the lid body 4 having the above-mentioned structures are respectively mounted with appropriate electronic parts. The ballast circuit board 20 and the ballast circuit board 21 are fixed to the bottom plate 5 of the box body 3 by an appropriate method.

In the case body 2, as shown in FIG. 2, a sponge-like urethane resin 22 is placed on the bottom plate 5 of the box body 3.
From the starter circuit board 20 and the ballast circuit board 2
1 is filled up until it reaches a position slightly below the upper end of the peripheral wall 6 of the box 3. As will be described later, the urethane resin 22 is formed by filling a so-called gel state of a liquid (urethane gel) into the case body 2 and then curing it.

Further, cords 23, 23 and 24 for electrically connecting to a discharge lamp and a battery as a power source (not shown) are provided on the circuit boards 20 and 21, respectively.
24 are connected.

That is, one end of each of the cords 23, 23 is connected to the starter circuit board 20, is led out from the opening 16 of the lid 4, and the other end thereof is connected to a discharge lamp as shown in FIG. A connector 25 for connecting is connected.

In the middle portion of the cords 23, 23, the outer peripheral surface of a cylindrical tube made of synthetic resin such as synthetic rubber having flexibility and insulation is provided, for example, stainless steel (SUS) or the like. A tube body 26 covered with a metal mesh made of is externally fitted.

The tube body 26 has one end fixed to the lid 4 using the holder 27 and the collar 28, and the other end fixed to the cords 23, 23 by suitable taping. That is, the holder 27 to which the tube body 26 is fixed is aligned with the end surface of the standing wall 16 of the lid body 4, and the holder 27
The screws 29, 29, 29 are inserted through the screw insertion holes (not shown), and the screw holes 19 of the mounting ear pieces 19, 19, 19 are inserted.
It is fixed to the lid body 4 by being screwed into a, 19a, 19a.

Further, one ends of the cords 24, 24 are connected to the ballast circuit board 21, and the case body 2 is provided with the notch 1 of the lid body 4.
A connector connected to a battery (not shown) is connected to the other end of the case body 2 which is led out from a portion opened by 2. A flexible bushing 30 is fitted as a cord holding member into the notch 12 of the lid 4 to close the opening, and the cords 24, 24 are provided.
Is holding.

The bushing 30 is formed of, for example, a synthetic resin such as synthetic rubber, and as shown in FIGS. 5 to 7, when viewed from above, the outer edge of the left end has a substantially arcuate shape. A plate-shaped base portion 31 and a top surface 31a of the base portion 31 are integrally formed with a substantially dome-shaped upper cover 32 in which the upper, front, rear and left sides of the upper surface 31a are closed and the right side is opened. It consists of The base 31 has cord insertion holes 33, 33 arranged in the front-rear direction on the upper surface 3
It penetrates from 1a to the lower surface 31b in a state of being inclined about 15 degrees so as to go leftward as it goes downward.

As shown in FIG. 5, the inside of each cord insertion hole 33 has a neck portion 3 whose diameter is reduced at regular intervals.
A large number of 3a, 33a, ... Are formed. The neck portions 33a, 33a, ... Are the cord insertion holes 33, 33.
When the cords 24, 24 are inserted into the
The outer peripheral surface of the case 4 is closely attached to prevent water and the like from entering the case body 2.

An engaging groove 34 is formed on the side surface of the base 31 except for the right side surface, and a step 35 is formed on the right end of the lower surface 31b.

As shown in FIG. 5, the cords 24, 24 penetrate through the cord insertion holes 33, 33 of the bushing 30, and the ends are led out from the opening on the right side surface of the upper cover 32. Together with the bushing 30, the notch 1 in the lid 4
Fitted in 2. At this time, the engaging groove 34 engages with the edge portion of the notch 12 of the lid body 4, and the step portion 35 engages and closely contacts with the opening edge of the box body 2 to hold the bushing 30 and to insert it into the case body 2. It is designed to prevent the entry of water, etc.

Next, the urethane resin 22 is put into the case body 2.
Will be described.

That is, first, a member such as the case body 2 that comes into contact with the urethane resin 22 is dried. This is because the urethane resin in the urethane gel state easily reacts with water.

Next, in order to prevent bubbles from forming in the urethane gel, the starter circuit board 20, the ballast circuit board 21, etc. are housed and fixed in the case body 2 in a reduced pressure atmosphere, and the cord 23, After drawing out 23, 24, and 24 to the outside of the box body 3, the gel urethane resin 22 is placed in the box body 3 at the position shown in FIG.
(Potting) until the lower end of the is embedded in the urethane resin 22.

Then, after applying a liquid gasket using a silicone adhesive to the sealing groove 15 of the lid body 4, the opening of the box body 2 is covered and closed with the lid body 4, and the lid body 4 is screwed into the box body 3. Fix with a stop. The cords 23, 23 and 24, 24 are respectively the opening 16 and the notch 12 of the lid body 4.
And the outer peripheral edge portion 1 of the lid body 4 and the step portion 6a of the box body 3
4 and the sealing groove 15 are engaged.

Finally, in order to apply heat to cure the urethane gel, the case body 2 is placed in a curing oven and the temperature is 8 degrees Celsius.
When heat treatment is carried out at a temperature of 0 degree for 4 hours, the urethane gel is solidified into a sponge-like urethane resin as described above. The silicone adhesive applied as a liquid gasket to the sealing groove 15 of the lid 4 cures at room temperature, but also cures at a temperature of 80 degrees Celsius.

The circuit device 1 is attached to the headlamp 36 as shown in FIG. The headlamp 36 uses a discharge lamp 37 as a light source,
The discharge lamp 37 is a reflecting mirror 3 arranged in a lamp body 38.
9, the discharge lamp 37 has the cords 23, and the connector 25 connected to the cord 23.

A fitting portion 40 is provided on the lower surface of the lamp body 38. The fitting portion 40 is provided with a rib 42 on the opening edge of the opening 41.
A fitting groove 43 is formed in the.

Thus, the circuit device 1 has the headlamp 36.
The standing wall 17 is fitted in the opening 41, and the fitting groove 43
The standing wall 18 is fitted therein, is supported from below by a mounting holder 44, and is mounted by fixing the mounting holder 44 to the lamp body 38 with a bolt (not shown).

At this time, the opening 16 through which the cords 23, 23 are led out is located in the opening 41 of the lamp body 38, and the standing walls 17 and 18 around the opening 16 are fitted together with the fitting portion 40 fitted therein. Thus, the watertightness is maintained, and the bushing 30 that fits into the notch 12 through which the cords 24, 24 are drawn and closes the notch 12 has a positional relationship facing the lamp body 36.

Finally, a modification of the bushing which is the cord holding member will be described.

As shown in FIGS. 9 and 10, the bushing 50 has a thick plate-like base 51 whose outer edge at the left end is substantially arcuate when viewed from above, and an upper surface of the base 51. 51a, an upper cover 52 is integrally formed to cover an upper part, a front part, and a rear part of a right third portion of the upper surface 51a. Then, the base 51 is penetrated by cord insertion holes 53, 53 arranged in the front-rear direction in a state in which the cord insertion holes 53, 53 are inclined by about 15 degrees so as to move leftward as going downward from the upper surface 51a to the lower surface 51b.

The upper cover 52 is formed by cutting out the left half of the upper cover 32 of the bushing 30. This is similar to the bushing 30 in that the openings of the cord insertion holes 53, 53 on the upper surface 51 a side cover the upper portion 5.
This is because the workability of inserting the cords 24, 24 into the cord insertion holes 53, 53 deteriorates when the cords are covered with the cords 2.

The inside of each cord insertion hole 53 is the same as the inside of the cord insertion hole 33 of the bushing 30.
Neck portions 53a, 53 having a reduced diameter at regular intervals
Many a, ... Are formed.

An engaging groove 54 is formed on the side surface of the base 51 except for the right side surface, and a slit 55 is formed on the right end of the lower surface 31b.

Therefore, the cords 24, 24 are, as shown in FIG. 10, the cord insertion holes 53, 53 of the bushing 50.
And the end portion is led out to the outside from the opening on the upper surface 51a side of the base portion 51, inserted under the upper cover 52 and led to the outside from the right side surface, and the bushing 50 is inserted into the notch 12 of the lid body 4. Be inserted. At this time, the engaging groove 54 engages with the edge of the notch 12 of the lid 4, the peripheral wall 6 of the box 2 enters the slit 55, and the lower end of the bushing 50 is embedded in the urethane resin 22. Bushing 50
And the intrusion of water and the like into the case body 2 are prevented.

[0045]

As is apparent from the above description, in the circuit device according to claim 1, at least one of a plurality of cords connected to the circuit board is filled with resin inside the case body. The cord holding member is led out to the outside of the case body through a notch provided in the case body and is held by a cord holding member having a cord insertion hole, and the cord holding member is fitted in the notch to close it, and inside the case body,
Since one end of the cord holding member with the cord insertion hole opened is embedded in the resin inside the case body, the cord holding member between the cord holding member and the lid or box and inside the hole for leading out the cord. Even if there is a gap between the cord and the cord, the inside of the case body is filled with resin, and one end of the cord holding member with the cord insertion hole opened is embedded in the resin inside the case body. Since the circuit board is not affected by water, rust and corrosion of metal parts,
It is possible to prevent current leakage.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the circuit formed on the circuit board is a lighting circuit that supplies electric power for lighting the discharge lamp. Since the case body is fixed to the headlamp using the discharge lamp as a light source and the cord holding member is provided on the side of the case body facing the headlamp, water is unlikely to splash on the bushing and the cord in rainy weather.

Further, in the circuit device according to a third aspect, in addition to the configuration according to the first or second aspect, the cord holding member is provided with a cord insertion hole and fits into the notch of the case body. Since it is composed of the base portion and the opening portion of the cord insertion hole and the upper cover that covers the cord led out from the opening portion, it is possible to prevent the cord insertion hole from being directly splashed with water, and It can be held securely.

Further, in the circuit device according to a fourth aspect, in addition to the configuration according to the first or second aspect, the cord holding member is provided with a cord insertion hole and is fitted with the notch of the case body. Since it is composed of a base portion and an upper cover that covers a part of the cord led out from the opening of the cord insertion hole, the cord can be securely held and the work of inserting the cord into the cord insertion hole can be performed easily. be able to.

It should be noted that the specific shapes and structures shown in the above-mentioned embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention is limited by these. Is not to be interpreted.

[Brief description of drawings]

FIG. 1 shows an example of implementation of the circuit device of the present invention together with FIGS. 2 to 8, and is a plan view.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a plan view of a box.

FIG. 4 is a bottom view of the lid.

5 is an enlarged cross-sectional view taken along the line VV of FIG.

FIG. 6 is an enlarged front view showing a bushing.

FIG. 7 is a right side view showing an enlarged bushing.

FIG. 8 is a sectional view schematically showing a state in which the circuit device of the present invention is attached to a headlamp.

FIG. 9 shows a modified example of the bushing together with FIG. 10, and this figure is a plan view.

FIG. 10 is an enlarged cross-sectional view showing a usage state of the bushing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit device, 2 ... Case body, 3 ... Box body, 4 ... Lid body, 1
2 ... Notch, 20 ... Circuit board, 21 ... Circuit board, 22 ... Resin, 23 ... Cord, 24 ... Cord, 30 ... Cord holding member, 31 ... Base part, 32 ... Top cover, 33 ... Cord insertion hole, 36 ... Head Lamp, 37 ... Discharge lamp, 38 ... Lamp body, 50 ... Cord holding member, 51 ... Base, 52 ... Top cover, 53 ... Cord insertion hole

Claims (4)

[Claims] 1. A circuit board on which electronic components are mounted is housed in a case body including a container-shaped box having an opening that opens toward one side and a lid that covers the opening of the box. In the circuit device, the case body is filled with resin, and at least one of the plurality of cords connected to the circuit board is led out of the case body through a notch provided in the case body and the cord is inserted. It is held by a cord holding member having a hole, the cord holding member is fitted into the notch to close the notch, and one end portion of the cord holding member having the cord insertion hole opened inside the case body is a case. A circuit device, wherein the circuit device is embedded in the resin inside the body. 2. A circuit formed on a circuit board is a lighting circuit for supplying electric power for lighting a discharge lamp, a case body is fixed to a headlamp using the discharge lamp as a light source, and a cord holding member is The circuit device according to claim 1, wherein the circuit device is provided on a side of the case body facing the headlamp. 3. The cord holding member is provided with a cord insertion hole and a base portion that fits into the notch of the case body, and an upper cover that covers the opening portion of the cord insertion hole and the cord led out from the opening portion. The circuit device according to claim 1 or 2, characterized in that. 4. The cord holding member is provided with a cord insertion hole and a base portion that fits into the notch of the case body, and an upper cover that covers a part of the cord led out from the opening portion of the cord insertion hole. The circuit device according to claim 1 or 2, which is characterized by the above-mentioned.