JPH07211560A - Ignition device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose is to construct a structure that is reliable, efficient, and has a long life in the process of connecting a conductive wire to a terminal. [Structure] By eliminating the mold resin under the terminals and making the terminal shape more rigid, connecting the conductive wires makes the height dimensions of the terminals and internal elements closer to each other,
Keep the overall size of the module low. [Effect] Since a reliable connection of conductive wires, a proper looping shape can be obtained, and a compact module can be stably constructed, an ignition device for an internal combustion engine of stable quality can be supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine, and more particularly to fixing a terminal integrally formed with a molded case.

[0002]

2. Description of the Related Art In the prior art, a conductive wire is connected by spot welding, soldering, parallel gap welding, or the like, which has a structure in which a molded portion under a terminal does not exist. However, the connection of this structure, for example, by ultrasonic welding of an aluminum wire has not been carried out because the rigidity of the terminal is insufficient.

[0003]

In the above-mentioned prior art, for example, in the case of ultrasonic welding of aluminum wire, the mold is applied to and supported by the lower part because of insufficient rigidity of the terminal.
Furthermore, by providing a gap in the lower part of the mold, ultrasonic waves during ultrasonic welding were efficiently diffused. However, in this structure, since the mold or the mold + gap exists in the lower part of the terminal, the upper surface of the terminal becomes higher in position, which makes it difficult to make the module compact in the height direction.

[0004]

To achieve the above object, the molding under the input / output terminals is stopped to keep the height of the terminals low. Resonance due to ultrasonic waves during ultrasonic welding occurs due to insufficient rigidity of the terminals or due to diffuse reflection of ultrasonic waves. Therefore, the terminal support structure should have an inverted U-shape or a U-shape. Improve. However, even if the terminal is a flat plate, use a flat plate if the rigidity is not insufficient.

[0005]

When a conductive wire is ultrasonically welded to the input / output terminal, the oscillation frequency is usually 50 to 150 kHz and the power is about 150 gf. In this case, even if there is no mold under the terminal and the terminal is a flat plate,
The amount of displacement of the terminal is Ymax = Wa ² (3L−a) / (6EI) = 0.9 μm, which shows that there is no problem.

Here, W: power a: distance from support point to wire L: terminal length E: Young's modulus I: second moment of area Further, the resonance frequency at this time is spring constant k = W / Ymax
= 166666 kgf / m f = SQR (k / m) / 2π = 24 kHz, and resonance due to insufficient rigidity can be avoided. The ultrasonic diffusion path is secured because the terminal does not directly contact the lower member, for example, the heat sink, and there is no diffuse reflection of diffusion.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an igniter 3 having a structure in which an aluminum wire 5 is ultrasonically welded to the input / output terminal 1 of the present invention and the lower mold resin of the input / output terminal 1 is eliminated. Example. The function of the igniter 3 is an actuator that causes the primary current of the ignition coil to conduct and cut off in synchronization with the ignition timing of the engine to generate a high voltage on the secondary side. The input / output terminal 1 receives a signal from an engine control unit (ECU) as an electric signal, processes the signal in the internal control circuit board 4 of the igniter module 3, and outputs the output signal to an ignition coil. It is a so-called electric route in Moyol that is sent to. The input / output terminal 1 and the control circuit board 4,
The switching element 6 is connected to the aluminum wire 5. Connection is ultrasonic welding (ultrasonic bonding)
According to the above, it is performed by an automatic machine or a manual machine. The overall module configuration of the igniter 3 is a configuration in which the control circuit board 4 and the switching element 6 are fixed on a heat sink (metal base) 7 by soldering or an adhesive and combined with a mold case 8. Is. The mold case 8 exchanges an electric signal with an external device by a method of integrally molding a connector integrated type and a faston type terminal. The igniter 3 is about M4 to M6 size of screws, and usually 2 to
It is tightened in 3 places and installed in the engine room. The temperature in the engine room is expected to rise from -40 ° C in winter to about + 130 ° C in summer. Further, when it is directly mounted on the engine, the vibration acceleration may be about 25 to 35 G or more. It is necessary to carry out a modling that can withstand such a harsh environment. For example, if the aluminum wire 5 is focused on, the longer the length of the aluminum wire 5, the better in order to reduce the damage of thermal stress due to repeated cycles of high temperature to low temperature. Further, as a method of reducing damage to vibration, it is better to shorten the acumi wire 5 as it is shorter. In order to keep these two contradictory properties in good balance, various experiments and computer analyzes show that the looping that minimizes the damage of thermal stress is the most effective even if the aluminum wire 5 is stretched as short as possible. I understand. As an ideal type, the positional deviation of the input / output terminal 1 and the control circuit board 4 or the switching element 6 in the height direction should be zero, and the wire span should be secured to some extent. But,
The most desirable thing. However, this often has the opposite property to the compactness of the module, and in reality, there is the current trend of designing the internal configuration after first determining the size of the module. It is a common practice to extend the life of each part as long as possible. However, such a method has a limit in extending the life. Further, since the lower mold resin of the input / output terminal 1 is present, a position shift occurs in the height direction, and it is difficult to make the module compact in the height direction.

Regarding the wire bonding method, a bonding pad is soldered to the wire bond portion of the input / output terminal 1 and bonded thereto, or a method of directly bonding to the input / output terminal 1 and the like. There is. Furthermore, the material of the input / output terminal 1 is
There are brass, phosphor bronze, iron-nickel alloy, etc., and as the type of plating, tin plating, nickel plating, gold plating, etc. are processed. The bonding wire includes an aluminum wire, a soft brass wire, an iron-nickel material, a nickel wire, a gold wire and the like, and they are joined by soldering, welding, ultrasonic welding or the like. The input / output terminal 1 shown in FIG. 1 is an embodiment in which the bonding pads 2 are soldered to two of the four terminals and the conductive wires 5 are directly bonded to the other two of the four terminals. 4 to 6 show an embodiment showing a shape in which the lower molding resin of the input / output terminal 1 is eliminated.
Is a flat plate, FIG. 5 is an inverted U-shape for improving rigidity, and FIG. 6 is a U-shape. It is possible to contribute to downsizing of the module while supporting bonding and connection of the module. By keeping the height dimension A of the input / output terminal 1 low,
It is possible to keep the dimensions of the module height B and the total height C low, and it is possible to reduce the weight of the entire module, which is advantageous for vibration.

[0009]

EFFECTS OF THE INVENTION According to the present invention, since unnecessary molding resin does not exist in the lower portion of the terminal, it is possible to always perform stable joining with respect to the connection of the conductive wire. Since it can be welded and selected regardless of type, a proper connection is always possible, so the service life is always stable,
A reliable module can be supplied.

[Brief description of drawings]

FIG. 1 is a plan view of an igniter adopting a terminal portion of the present invention as seen from directly above.

FIG. 2 is a front view of FIG. 1 and is an explanatory view of a module in a height direction.

FIG. 3 is a side view of FIG. 1, and is an ASSY diagram including conductive wires and internal elements.

FIG. 4 is a detailed view of the flat terminal portion of the present invention.

FIG. 5 is a detailed view of an inverted U-shaped terminal portion of the present invention.

FIG. 6 is a detailed view of a U-shaped terminal portion of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input / output terminal, 2 ... Bonding pad, 3 ... Igniter, 4 ... Control circuit board, 5 ... Conductive wire, 6
... switching element, 7 heat sink (metal base), 8 mold case.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Norio Moriyama 2520, Takaba, Katsuta-shi, Ibaraki Hitachi, Ltd. Automotive Equipment Division (72) Inventor Katsuaki Fukatsu 2477 Kashimayatsu, Katsuta, Ibaraki 3 Within Hitachi Automotive Engineering Co., Ltd.

Claims (2)

[Claims] 1. A conductive wire is connected in an internal combustion engine ignition device comprising a molded case having an external input / output terminal integrally molded with the molded case, a switching semiconductor element, a control circuit board, and a heat sink. An ignition device for an internal combustion engine, wherein a supporting structure of the input / output terminal in the mold part is a cantilever supporting structure of the conductive wire connecting part. 2. The input / output terminal for connecting the conductive wire has an inverted U-shape or a U-shape, and the support structure in the mold is rigid with respect to the conductive wire connection direction and the vertical direction. An ignition device for an internal combustion engine, characterized by having an improved structure.