JPH0639099Y2 - Electronic engine ignition circuit device - Google Patents

Description

[Detailed description of the device] [Technical field to which the device belongs]

The present invention is an electronic engine ignition circuit device, and more specifically, is provided for ignition of an engine mounted on a vehicle such as an automobile, receives an input signal from a pickup that detects the rotation of the engine, and outputs an ignition current synchronized with the input signal. A circuit device for giving to an ignition coil, an input section for receiving the pickup signal, and an electronic ignition control section for receiving a pickup signal via the input section and issuing an opening / closing command at a timing according to a predetermined ignition characteristic, The present invention relates to an electronic engine ignition circuit device in which an output part for opening / closing an ignition current according to the opening / closing command is housed in a case, and a connection path from the case to the pickup and the ignition coil is derived.

[Prior art and its problems]

Electronic engine ignition devices have higher control accuracy of engine ignition timing than mechanical ones and are suitable for complicated ignition timing control, so they are widely used especially for ignition control of automobiles and motorcycle engines. It has come to see. The electronic ignition system is used to advance the ignition timing in response to changes in the engine speed, as well as to advance the ignition according to the engine intake pressure and air-fuel ratio. When required, it becomes necessary to improve the accuracy of ignition timing control more than before. Also, as vehicle performance has become more sophisticated, the space inside the engine room has become more difficult, and as a result, not only is the electronic circuit of the ignition device made smaller, but also the overall layout including the ignition coil and distributor, and the interconnections between them. The need to streamline is coming out. However, the biggest problem in improving the control accuracy and reducing the required space is the problem of noise penetrating into the electronic circuit. This problem uses a highly sensitive amplifier in the electronic circuit. The higher the control accuracy, the more serious. Of course, it is easy to store the electronic circuit in the metal case, and it is possible to take measures such as using shielded wires for wirings or using a filter at the entrance of the electronic circuit. However, it is very costly to completely implement such noise countermeasures. Another problem is that the miniaturized ignition device requires that the ignition coil and the output transistor for driving be housed in the same case as the electronic device, as is well known. Since the collector of the output transistor and the connecting wire connected to it become a noise source whose potential changes remarkably when the ignition current to the ignition coil is interrupted, the problem of internal noise in addition to external noise is seen from the electronic circuit perspective. You have to do it. As a conventional technique for this kind of problem, for example, Japanese Patent Publication Sho
Known are 58-54268 and Japanese Patent Sho 59-30908. The former is intended to solve the problem by devising the terminal arrangement of the case that houses the electronic circuit, and the latter is to cancel the noise that enters the input side of the electronic circuit with a pulse of the opposite polarity. is there. However, the former means inevitably causes some restrictions on the terminal arrangement, and hence the wiring. The latter is, so to speak, a good idea to control poison with poison, but if the condition of external noise changes due to changes in the installation conditions and operation of the device, the countermeasures against the external noise may be adversely affected and the malfunction of the electronic circuit may occur. It is hard to say that it can be reliably prevented.

[The purpose of the device]

The object of the present invention is to obtain an electronic engine ignition circuit device which has a built-in noise prevention performance that can be applied to a wide range of applications and whose protection effect is not affected even if there are restrictions on installation conditions or changes in the operating environment. It is in.

[Key points of the device]

According to the invention, this object is for an electronic engine ignition circuit arrangement of the type mentioned at the beginning, between the connection to the pickup and the connection between the input and the output to derive the ignition current to the ignition coil. It is achieved by arranging a conductor at least in part so that the connection path is surrounded by the conductor and connecting the conductor to a reference potential point of the circuit device. In a recent electronic engine ignition circuit device, an ignition control unit is integrated in a semiconductor chip, and is mounted or mounted on a thick film printed circuit board, and is integrated with a transistor of an output unit into a so-called hybrid integrated circuit. Often stored in a case. At this time, the input section that receives the input signal from the pickup needs to adjust the waveform and the input potential, and it is necessary to have a high resistance value in order to obtain a sufficient filter effect. It is advantageous to make it. Further, the derivation path of the ignition current from the transistor of the output part should originally be drawn directly from the collector to the outside of the case, but it is built in the substrate due to restrictions on the arrangement of parts in the case and convenience of parts mounting. In many cases, it has to be derived through a connecting path. When the input section and the connecting path are formed on the same substrate in this way, noise from the connecting path is likely to give an obstacle to the input section. In this case, the conductor in the present invention may be formed as a printed conductor on the substrate, and experience shows that it is effective even if the printed conductor has a narrow width and its conductivity is not so high. The noise prevention effect can be easily achieved in a very small space. The cause of noise interference in the case that houses the circuit device is not only the electrostatic coupling but also the condition of the substrate surface. Therefore, even with such a relatively simple means, a sufficient effect can be obtained. Conceivable. The reference potential point to which such a conductor is to be connected may be the ground potential point at the very end, or, for example, the B power source potential point if the potential point is relatively stable and has a low internal impedance to alternating current. May be. When the ignition current is directly derived from the output transistor to the outside of the case, the above-mentioned problem of noise interference on the same substrate is greatly reduced, but there are many problems in the terminal part as a connection path penetrating the case. . Since the outer surface of the case of the terminal is in a bad environment in the engine room, the interference problem due to leakage on the surface of the terminal insulation is often more important than the interference due to electrostatic coupling. As an advantageous aspect of the present invention for such a case, a conductor is arranged so as to surround at least one of a connection terminal to the pickup and a connection terminal for deriving an ignition current, for example, a conductor for a terminal mold part. It may be buried. The form of the input signal from the pickup to the electronic engine ignition circuit device according to the present invention may be an analog waveform or a digital waveform. In the former case, the shape of the waveform is the basis for controlling the advance angle, etc., so the performance and accuracy are likely to be affected by the mixing of noise, and the effect obtained by the present invention is so great. However, even if the input signal is a digital waveform that is strong against noise interference, a high noise level may cause a malfunction, and the pulse width is the basis for ignition timing control. The above problem arises. Therefore, the present invention has a certain degree of effect with respect to such a digital input method, although it has a different degree.

[Example of device]

Next, an embodiment of the present invention will be described with reference to the drawings. Before starting the description of the mode of the conductor arrangement in the present invention, the general configuration and structure of the apparatus will be described with reference to FIGS. The electronic engine ignition circuit device which is the object of the present invention is indicated by 10 in the circuit of FIG. 3, and receives the input signal from the pickup 1 on the left side of the figure at terminals P1 and P2, and the terminal on the right side of the figure. An ignition current is supplied from C to the primary side of the ignition coil 2, and a high voltage for ignition is generated on the secondary side by the interruption of the ignition current. The terminal B receives a B power supply voltage for the entire apparatus from a DC power supply such as the battery 3, and the lower terminal E is usually a case and is attached to the ground potential. The rotor 1a of the pickup 1 is mechanically coupled to the movable part of the engine, and its coil 1b emits, for example, repetitive triangular wave analog signals. The electronic engine ignition circuit device 10 includes an input section 20, an ignition control section 30, and an output section 40 for receiving this signal, and the ignition control section 30 in this unit is usually the minimum semiconductor shown in FIG. 4 (a). It is integrated in a chip, the output section 40 is an individual semiconductor element, and the input section 20 is formed and mounted or mounted on the substrate 60 of FIG. The input section 20 is a kind of filter circuit including, for example, two resistors 21 and 22 and one capacitor 23 connected in a T shape, and acts as a suppressor for noise coming from the pickup 1. , Also serves to shape the waveform of the input signal from the terminals P1 and P2. Also, this input unit 20
A resistor 24 for applying a potential to an input point to the ignition control unit 30 is connected to the B power source potential point. The ignition control unit 30 may have various configurations depending on the required ignition timing or advance angle characteristic, and FIG. 3 conceptually shows this. The first stage amplifier 31 is fed by a constant power source 36,
A signal from the pickup is received by the input on the upper side of the figure via the input unit 20 described above. The block at the next stage is the advance angle control circuit 32, which supplies a closing angle signal having a predetermined advance angle value of the transistor 33 on the right side of the block and also supplies the signal from the pickup to the lower input of the first stage amplifier 31 in the figure. Give a reference value to compare with. The advance control circuit 32 and the first stage amplifier 31 are driven by the constant voltage from the constant voltage circuit 35. The closing angle signal is transmitted from the transistor 33 to the transistor 34 in the next stage, and is then transmitted to the output section 40. Although the advance angle control circuit 32 is important in the operation characteristics of the ignition control unit 30 as a whole, the input circuit unit of the first stage amplifier is also important from the viewpoint of noise prevention, which is the focus of the present invention. If the ignition control unit 30 is integrated into a circuit as described above, the ignition control unit 30 occupies a very small area in the device, and the risk of noise interference is extremely small. However, since the signal value itself of the input signal from the pickup to the first-stage amplifier 31 is meaningful for ignition timing control, especially when it is an analog signal, if it changes slightly due to noise, the control characteristic changes accordingly. Therefore, if the signal value is greatly affected, a malfunction will occur. The main body of the output section 40 is an output transistor 41 configured as, for example, a Darlington transistor, to which a protection diode, a zener diode, or a resistor is attached as shown in the figure. An ignition current is derived from the collector of the main transistor at terminal C. The potential of the terminal C is substantially equal to the potential of the ground point E when the output transistor 41 is on, and jumps up to the B power source potential or multiples thereof when the output transistor 41 is off to generate high frequency vibration determined by the natural frequency of the ignition coil 2. . These jumps and vibrations are extremely large in value in a short time, but are extremely harmful noise sources in the device 10. FIG. 4 is a structural example of an electronic engine ignition circuit device. FIG. 4A is a sectional view taken along the line YY of FIG. 4B, and FIG. 4B is a sectional view of FIG. The -X arrow cross section is shown. As shown in FIG. 3A, a small integrated circuit of the ignition control unit 30 and a relatively large individual element accommodating the output unit 40 are mounted on a printed circuit board 60 in which the input unit 20 is built, and a case is mounted.
It is stored in 50. As can be seen from FIG.
The substrate 60 is attached to the bottom surface of a case body 51 made of metal, and one side wall of the case body 51 is fitted with a terminal mold body 53 that insulatively supports four terminals. Each of the terminals P1, P2, B, and C is connected to the connection area 60a of the printed board by a flexible connection line 66, and after this connection is completed, the case body 51 is cast-cured with silicone gel or the like. . The lid 52 may be made of metal or resin, and is snap-fitted to the case main body 51 after the resin is cast and cured, for example, via the engaging portions 51a and 52a. The arrangement order of the terminals embedded in the terminal mold body 53 shown in FIG. 4 (a) is merely one example, but in this example, the terminals C, which are noise sources as described above, are arranged side by side. A signal input terminal P1 to the input section 20 that is most susceptible to the above is provided.
From the output section 40, leads 40b, 40c, 40e from the base, collector, and emitter of the output transistor 41 are output. Of these, the collector lead 40c is directly connected to the above-mentioned terminal C in order to prevent noise interference. However, the case where this is connected to the terminal C via the printed board 60 will be described below. FIG. 1 shows the main part of the printing pattern of the printed board 60. The printed board 60 may be a so-called printed board, but in this figure, an example is shown in which a circuit pattern is formed on a ceramic substrate such as alumina by a thick film printing and firing technique. The same parts as those in FIG. 3 are designated by the same reference numerals. The part hatched from the lower left side to the left side in the figure is the printed conductor part of the input part 20.
25, 26, 27, and resistors 21, 22 are printed and fired between them. A capacitor 23 is attached by soldering or the like between the input conductor portion 26 and the ground conductor portion 62.
A resistor 24 is printed and fired between the B power conductor portion 61 and the B power conductor portion 61. The circle in the input conductor 25 indicates the terminal P1.
And the connection area 25a connected by the above-mentioned connection line 66,
On the other hand, the tip 27a of the input conductor portion 27 is a portion connected to a bump of, for example, a flip chip in which the ignition control portion 30 is integrated. The individual element accommodating the transistor 41 of the output section 40 is mounted in the printed circuit board 60 at a position surrounded by a dashed line, and the tips of the three leads 40b, 40c, 40e are printed conductor sections 65, 63, respectively. , 64 and soldering, etc. The collector conductor portion 63 for guiding the ignition current has a connection area 63a at the lower center of the figure, and is connected to the terminal C via a connection wire 66 from this area. Among the printed conductors of the pattern shown in FIG. 1, the one corresponding to the reference potential point is the B power source conductor portion.
61 and the ground conductor portion 62, which are connected areas 61a,
It has 62a and is connected to the terminals B and P2 via the connection line 66.
This inner ground conductor portion 62 has another connection area 62b,
Along with the connection area 64a of the printed conductor portion 64 connected to the emitter lead 40e of the previous output section 40, as can be seen from FIG. Connected to point E. In the substrate 60 having the above-mentioned printed pattern, it is the portion indicated by 71 arranged between the collector conductor portion 63 and the input conductor portion 25 that constitutes the conductor for noise interference prevention.
The upper end of the figure is connected to the ground conductor portion 62. Further, in this embodiment, the conductor 71 also separates the printed conductor portion 65 connected to the base lead of the output portion 40 from the collector conductor portion 63, and the right side of the collector conductor portion 63 in the drawing is also the ground conductor portion. It is surrounded by 62. In this way, the collector conductor portion 63, which is a noise source, is surrounded on three sides by the conductor 71 and the ground conductor portion 62 at the reference potential, and the remaining one is also surrounded by the case body 51 at the ground potential when it is housed in the case. , Almost completely isolated from the rest of the device. The above-mentioned input conductor portions 25, 26, 27 of the input circuit 20 which are easily affected by noise are elongated and extend from the left side to the upper side of the figure, but as can be seen from the figure, all of them are at the ground potential. 62, B Power conductor part 61 or enclosed by the case body when housed in the case and protected from external noise. FIG. 2 shows a different embodiment of the present invention. In the drawing, the state of the terminals B and C in the previous FIG. 4 (a) is seen from the inside of the case 50 in a partially sectional perspective view. Has been done. of course,
These terminals B and C are embedded in the terminal mold body 53. The conductor 72 in this embodiment is provided so as to extend from the terminal B at the B power source potential, which is one of the reference potentials, and substantially surround the terminal C at the collector potential, which is a noise source. That is, the conductor 72 is composed of a half ring portion 72a which surrounds the terminal C on three sides and a connecting portion 72a which connects the half ring portion 72a to the terminal B. Of course, the half ring portion 72b may be formed in a ring shape that completely surrounds the terminal C, but the structure shown in the figure can be formed more easily by punching and bending when the terminal B is manufactured, and is substantially the same as the ring shape. The isolation effect of C can be obtained. When the terminals B and C and the conductor 72 are embedded in the terminal mold body 53, it is better to prevent the outer end surface 72c of the case of the conductor 72 from protruding from the surface of the mold body 53 due to contamination or the like. This is advantageous because it is less likely to be adversely affected. This embodiment can also be used in combination with the previous embodiment shown in FIG.
It can also be used when the ignition current is directly derived from the terminal 40c to the terminal C.

[Effect of device]

As described above, according to the present invention, in the electronic engine ignition circuit device in which the input portion, the ignition control portion, and the output portion are housed in the case, and the connection path from the input portion is led out of the case. A conductor is arranged at least at a part between a connection path to the pickup and a connection path for deriving an ignition current from the input part and the output part to the ignition coil, and the connection path is surrounded by the conductor. Since the circuit is connected to the reference potential point of the circuit device, it is possible to effectively protect the noise sensitive input portion from the influence of the noise source existing in the case. External noise enters the device from each terminal of the electronic engine ignition circuit device. Among them, the noise coming from the terminals at the reference potential (P1 and B described above) is the AC at the reference potential point. Since it is a low impedance potential to, the noise disturbance is not noticeable. The rest is the terminal connected to the input section (P1 above)
And the noise from the terminal (C mentioned above) connected to the ignition coil, which is the noise source itself, but the latter is effectively isolated from the input section by the present invention, so no noise interference occurs in the input section. It is inevitable that external noise will enter the input section from the input terminal, but originally this input section is for external noise and is designed to effectively absorb the noise input from the terminal. . In other words, this input section is weak against the internal noise but strong against the external noise, and if the present invention is not made to feel the internal noise, the strength against the external noise is exerted and the entire device is noisy. Will not be affected by. As can be seen from the above description, the electronic engine ignition circuit device according to the present invention is essentially independent of the grounding conditions and operating environment of the device as in the prior art, and is applicable to a very wide range of applications. As a result, the device can be effectively protected from the influence of internal noise. In this way, the electronic engine ignition circuit device according to the present invention can be integrated into a small device while maintaining high ignition timing control accuracy, and a noise source such as a distributor in a narrow engine room with a lot of noise sources or in the noise source. It can be installed and installed on itself, and can be used under the condition that there is no restriction such as terminal order.

[Brief description of drawings]

The drawings are all for explaining the present invention. Among them, FIG. 1 is a pattern layout diagram of a main portion of a printed conductor in a substrate showing an example in which the present invention is applied to a printed substrate portion of an electronic engine ignition circuit device.
FIG. 3 is a partial cross-sectional perspective view of a main part of a terminal showing an example in which the present invention is applied to a terminal portion of an apparatus, FIG. 3 is a circuit diagram showing an entire circuit of the apparatus together with a pickup and an ignition coil, and FIG. It is sectional drawing which shows a structure. In the figure, 1: pickup, 2: ignition coil, 10: electronic engine ignition circuit device, 20: input section, 30: ignition control section, 40: output section, 5
0: case, 60: printed circuit board, 71, 72: conductor, B, C, P1, P2: terminals.

Claims (4)

[Scope of utility model registration request] 1. A circuit device for receiving an input signal from a pickup for detecting the rotation of an engine and supplying an ignition current to the ignition coil in synchronism with the input signal. An electronic ignition control unit that receives a pick-up signal and issues an opening / closing command at a timing according to a predetermined ignition characteristic, and an output unit that opens / closes an ignition current according to the opening / closing command are housed in a case. In which the connection path to the pickup and the ignition coil is derived, the ignition control unit is configured as a semiconductor integrated circuit, and a connection for deriving an input unit and an ignition current is provided on a printed circuit board mounting the integrated circuit. A path is created and is connected to at least part of the connection to the pickup and the connection between the input and the output to derive the ignition current from the output to the ignition coil. A conductor connected to a reference potential point of the device is arranged, the case penetrating portion of the connection path is configured as a connection terminal, and surrounds at least one of the connection terminal to the pickup and the connection terminal for deriving an ignition current. An electronic engine ignition circuit device, characterized in that the conductor is provided in the. 2. An electronic engine ignition circuit device according to claim 1, wherein an ignition current is directly derived from an output portion to a connection terminal. 3. An electronic engine ignition circuit device according to claim 1, wherein the reference potential point is a ground potential point. 4. An electronic engine ignition circuit device according to claim 1, wherein the reference potential point is a B power source potential point for supplying power to the circuit device.