JP2002285866A - Throttle device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing man-hours of a throttle device 1 housing a circuit board 3 in a throttle body 2 and to secure a good heat radiation property of the circuit board 3. SOLUTION: In resin molding of the throttle body 2, the circuit board 3 equipped with a heat sink 10 via an insulating member 11 is formed in the throttle body 2 by insert molding so that a radiation face 10a in the heat sink 10 is exposed to the outside face of the throttle body 2, while a connector 2a for connecting the circuit board 3 to an external wire is formed by integral molding in a position matching a terminal 6 on the circuit board 3 inside the throttle body 2. In this way, complicated work required for a conventional throttle device assembling process, such as the installation of the circuit board 3 to the throttle body 2, attachment of a hermetic packing and installation of a cover, can be dispensed with, and assembly man-hours for the throttle device can be greatly reduced. In addition, the good heat radiation property of the circuit board 3 can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a throttle device for adjusting an air flow rate flowing through an air passage of an engine and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a throttle body for adjusting an air flow rate flowing through an air passage of an engine by changing an opening degree of a throttle valve is formed by aluminum die casting. In recent years, in order to reduce the weight and cost, the throttle body has been made by resin molding. In the case of aluminum die casting, machining of the throttle valve bearing and the like is required. However, if molding is performed using a resin having a low coefficient of thermal expansion, the above-described processing becomes unnecessary, and the cost can be reduced while reducing the weight.

On the other hand, in order to reduce the man-hour for assembling the engine or the vehicle on which the engine is mounted, for example, to reduce the man-hour for arranging and connecting the wire harness, the electronic control unit is relocated to the vicinity of the engine or integrated with the engine peripheral equipment. Modularization is under consideration. For example, JP
Japanese Patent Application Laid-Open No. 1-294216 proposes that an electronic control unit is integrally mounted on a throttle body. In this technique, a circuit board, which is an electronic control device, is fixed to a storage unit provided integrally with a throttle body, and is covered with a cover. Further, a connector for connecting to a wire harness as external wiring is attached to the circuit board.

[0004]

In such a configuration, it is necessary to simultaneously seal the two places between the cover and the connector and between the cover and the housing when the cover is mounted, to maintain airtightness. That is, the sealing surface does not become a single plane,
It becomes a complicated shape that is bent three-dimensionally. For this reason, there is a problem that it is difficult to attach a sealing material such as a rubber packing, or it is difficult to obtain an effective surface pressure in the sealing portion and thus a sufficient sealing property cannot be obtained.

When an electronic control unit is integrally mounted on a resin throttle body, the resin generally has a lower thermal conductivity than aluminum, so that the heat dissipation of the electronic control unit may be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to reduce the number of assembling steps by integrally forming a circuit board, which is an electronic control unit, during resin molding of a throttle body. An object of the present invention is to provide a throttle device which can be reduced and a method of manufacturing the same.

Another object of the present invention is to provide a throttle device and a method of manufacturing the same, which can ensure sufficient heat radiation of a circuit board by easy means.

[0008]

In order to achieve the above object, the present invention employs the following technical means.

According to the first aspect of the present invention, a throttle body made of resin having an air passage formed therein, and a throttle valve rotatably housed and held in the air passage and adjusting an air flow rate flowing through the air passage. And a circuit board on which electronic components are mounted, wherein the circuit board is integrally formed with a throttle body made of resin in a throttle device integrally housed and fixed to the throttle body side. As a result, the number of steps for assembling the circuit board integrated type throttle device can be greatly reduced.

According to the second aspect of the present invention, the connector for electrically connecting the circuit board to the outside is integrally formed with the throttle body. This eliminates the need for a seal between the connector and the throttle body, thereby greatly reducing the number of assembling steps of the throttle device integrated with the circuit board.

According to the third aspect of the present invention, the circuit board is a flexible board having flexibility, and the flexible board is arranged along the outer peripheral side of the air passage. This allows the heat generated by electronic components mounted on the flexible substrate having heat generation, for example, power semiconductor elements, to be radiated to the airflow flowing through the air passage of the throttle body. Sufficient heat dissipation can be ensured.

Further, the size of the throttle device can be reduced in size.

According to a fourth aspect of the present invention, a heat radiating member is mounted on the circuit board, and the heat radiating member is exposed on the outer surface of the throttle body so as to radiate heat. Thereby, the heat generated by the electronic components mounted on the circuit board having heat generation, for example, the power semiconductor element, can be effectively radiated into the air around the throttle body via the heat radiation member. Therefore, sufficient heat radiation of the circuit board can be reliably ensured.

According to the fifth aspect of the present invention, a throttle device integrated with a circuit board can be efficiently manufactured with a small number of steps.

According to the sixth aspect of the present invention, it is possible to efficiently manufacture a circuit board-integrated throttle device excellent in heat radiation of the circuit board with a small number of man-hours.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 shows a sectional view of a throttle device 1 according to an embodiment.

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

The throttle device 1, as shown in FIG.
A throttle valve 7 is rotatably held in an air passage 2b formed in the throttle body 2, and the amount of air taken into the engine is adjusted by changing the opening of the throttle valve 7. Further, a circuit board 3 which is an electronic control unit for engine control is provided on the throttle body 2.
Are integrally accommodated. The air taken into the engine flows in the direction of the arrow in FIG. In FIG. 1, an air filter (not shown) is connected to the left side of the throttle device 1, and an intake manifold (not shown) for distributing and introducing intake air to each cylinder of the engine is connected to the right side. I have.

The throttle body 2 is formed by molding a high-strength resin with small dimensional changes at high temperatures. An air passage 2 b is formed in the throttle body 2, and a shaft 8 for holding and fixing the throttle valve 7 is inserted in a direction orthogonal to the axial direction of the air passage 2 b so as to be rotatable at a substantially central portion in the axial direction. Is held. Also,
The circuit board 3 is built in by integrally molding the throttle body 2 at the time of molding. Further, a connector 2 for connecting the circuit board 3 to external wiring (not shown)
a is formed at a position corresponding to the terminal 6 on the circuit board 3 of the throttle body 2.

The circuit board 3 constituting the electronic control unit includes:
Various electronic components 4 are mounted, and a pressure sensor 5 for detecting an intake pressure is mounted. This pressure sensor 5
Has an introduction port 5a for introducing a fluid to be detected (air in this embodiment) to a detection unit (not shown). When the circuit board 3 is integrally formed with the throttle body 2, the introduction port 5a It is open to the passage 2b. Further, a terminal 6 which is an electric terminal of a connector 2 a for connecting the circuit board 3 to an external wiring (not shown) is joined to a predetermined portion of the circuit board 3.

Next, a method of assembling the throttle device 1 according to the first embodiment of the present invention will be briefly described.

The manufacturing process of the throttle device 1 includes a process of mounting various electronic components 4 on the circuit board 3, a process of molding the throttle body 2 integrally with the circuit board 3, and a process of attaching the throttle valve 7 and the like to the throttle body 2. It is composed of the above three steps.

(1) Mounting Step of Circuit Board 3 Here, various electronic components 4 are mounted on the circuit board 3. Further, a terminal 6 which is an electric terminal of a connector 2a for connecting the circuit board 3 to an external wiring (not shown) is joined to a predetermined portion on the circuit board 3.

(2) Resin molding of the throttle body 2 In a molding die (not shown) of the throttle body 2, (1)
The circuit board 3 completed by the step is mounted. At this time,
The terminal 6 fixed to the circuit board 3 is held at a portion corresponding to the connector 2a in a mold (not shown).
Accordingly, the circuit board 3 is held at a predetermined position in the molding die during resin molding, and the positional relationship between the connector 2a integrally formed with the throttle body 2 and the terminal 6 can be accurately maintained. Next, the throttle body 2 is molded by injecting a resin into a mold.

(3) The throttle valve 7, the shaft 8, the seal member 9 and the like are mounted on the throttle body 2 completed by the process of (2).

In the throttle device 1 according to the first embodiment of the present invention described above, the throttle body 2
When the resin is molded, the circuit board 3 is integrally molded (insert molded) into the throttle body 2 and the connector 2a for connecting the circuit board 3 to the external wiring is connected to the terminal 6 on the circuit board 3 in the throttle body 2. It was integrally molded at the corresponding position. This allows the circuit board 3 to be attached to the throttle body 2 in the conventional throttle device assembling process.
The complicated work of mounting, mounting the airtight packing, and mounting the cover becomes unnecessary, and the man-hour for assembling the throttle device can be greatly reduced.

Further, good airtightness of the circuit board 3 and the connector 2a can be maintained.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
1 shows a sectional view of a throttle device 1 according to an embodiment.

In the second embodiment, the circuit board 3 is provided with a heat sink 10 as a heat radiating member, and the heat sink 10 is exposed to the outer surface of the throttle body 2 so as to radiate heat.

The heat sink 10 is formed of a material having a high thermal conductivity, such as aluminum or brass, and is mounted on the circuit board 3 at a position corresponding to a heat-generating electronic component such as a power semiconductor element. An insulating member 11 having excellent thermal conductivity is attached between the heat sink 10 and the circuit board 3.

Next, a procedure for manufacturing the throttle device 1 according to the second embodiment will be described.

First, the heat sink 10 is mounted on the circuit board 3 on which the mounting of the various electronic components 4 and the joining of the terminals 6 are completed.
And the insulating member 11 is fixed by bonding or the like.

Next, in a resin molding (insert molding) step of the throttle body 2, the circuit board 3 on which the heat sink 10 and the insulating member 11 are fixed is set in a molding die of the throttle body 2. Here, the surface of the heat sink 10 on the side opposite to the circuit board 3, that is, the heat radiation surface 10a
To the mold. Therefore, the throttle body 2
When the resin is molded, the heat radiation surface 10a is exposed from the throttle body 2.

In the throttle device 1 according to the second embodiment of the present invention described above, the heat sink 10 is mounted on the circuit board 3 via the insulating member 11, and the heat radiating surface 10a of the heat sink 10 is It was exposed to the outside. As a result, the same effect as that of the first embodiment can be obtained, and in addition, the heat generated in the electronic component 4 mounted on the circuit board 3 having heat generation, for example, a power semiconductor element or the like, can be obtained. Can be effectively radiated into the air around the throttle body via the heat sink 10, so that sufficient heat radiation of the circuit board 3 can be reliably ensured.

In the second embodiment described above, the heat sink 10 is connected to the insulating member 1 as shown in FIG.
Although it is mounted on the circuit board 3 via the connector 1, it may be mounted on the electronic component 4 side as shown in FIG.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
1 shows a sectional view of a throttle device 1 according to an embodiment.

In the third embodiment, the circuit board 3 of the second embodiment is arranged along the outer peripheral side of the air passage 2b of the throttle body 2 as a flexible board 30, and the heat sink 10 is connected to the air of the throttle body 2. The heat radiating surface 10a of the heat sink 10 is exposed to the passage 2b so as to be capable of radiating heat.
Thus, in addition to the same effect as that of the first embodiment, the heat generated by the heat-generating electronic components 4 among the electronic components 4 mounted on the circuit board 3 can be obtained. Can be effectively radiated into the air flowing through the air passage 2b of the throttle body 2 through the heat sink 10, so that sufficient heat radiation of the circuit board 3 can be ensured.

By arranging the flexible board 30 along the outer peripheral side of the air passage 2b of the throttle body 2, the size of the throttle device 1 can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a throttle device 1 according to a first embodiment of the present invention.

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

FIG. 3 is a sectional view of a throttle device 1 according to a second embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a modification of the throttle device 1 according to the second embodiment of the present invention.

FIG. 5 is a sectional view of a throttle device 1 according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 throttle device 2 throttle body 2a connector 2b air passage 3 circuit board 4 electronic component 5 pressure sensor 5a introduction port 6 terminal 7 throttle valve 8 shaft 9 sealing member 10 heat sink (heat radiating member) 11 insulating member

Continued on the front page (72) Inventor: Kanichi Yagi 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3G065 CA00 CA26 HA21 HA22 3G301 JA17

Claims (6)

[Claims] 1. A throttle body made of resin having an air passage formed therein, a throttle valve rotatably housed and held in the air passage, and adjusting a flow rate of air flowing through the air passage, and electronic components mounted thereon. And a circuit board, wherein the circuit board is integrally accommodated and fixed to the throttle body side, wherein the circuit board is formed integrally with the throttle body by resin. 2. The throttle device according to claim 1, wherein a connector for electrically connecting the circuit board to the outside is integrally formed with the throttle body. 3. The circuit according to claim 1, wherein the circuit board is a flexible board having flexibility, and the flexible board is arranged along an outer peripheral side of the air passage. Throttle device. 4. A heat radiation member is mounted on the circuit board,
The throttle device according to any one of claims 1 to 3, wherein the heat radiating member is exposed to an outer surface of the throttle device so as to radiate heat. 5. The method for manufacturing a throttle device according to claim 1, wherein an electronic component is mounted on the circuit board, and resin molding is performed integrally with the circuit board. A method of manufacturing a throttle device, comprising: a step of forming the throttle body according to (1); and a step of mounting the throttle valve in the air passage of the resin-molded throttle body. 6. The method for manufacturing a throttle device according to claim 4, wherein: a step of mounting an electronic component on the circuit board; a step of mounting the heat radiation member on the circuit board; A method of manufacturing a throttle device, comprising: a step of forming the throttle body by integrally molding a resin; and a step of mounting a throttle valve in the air passage of the resin-molded throttle body.