JP2007270755A - Ion current detection device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive, compact and highly reliable ion current detection device for an internal combustion engine. <P>SOLUTION: A diode array 1 consisting of a voltage regulation diode for an ion current detection power source and a diode for secondary coil discharge current is implemented by C4 method together with a diode 4 for ion current, ion current detection resistance 5, a power source capacitor of an ion current detection circuit on a ceramic substrate 3 and an IC2 keeping a current voltage conversion circuit disposed on the same semiconductor as a control circuit and protection circuit of a primary current interruption element. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ion current detection device for an internal combustion engine, and relates to realizing miniaturization, high reliability, and cost reduction.

  In an internal combustion engine such as an automobile engine, there is an ion current detection device for an internal combustion engine disclosed in FIG. In FIG. 3, 51 is a primary current interrupting element, 52 is a control circuit, 53 is a battery power supply, 54 is an ignition coil, 55 is an ignition plug, 56 is an ion current detection power supply circuit, 57 is an ion current detection resistor, and 58 is A current-voltage conversion circuit 59 is an ion signal processing circuit or an output circuit. 2. Description of the Related Art Conventionally, in such an ion current detection device for an internal combustion engine, there are some which are provided with various kinds of functions for protecting the switching element.

  In the figure, an ionic current detection device for an internal combustion engine includes an ignition coil 45 including a primary coil and a secondary coil that is electromagnetically coupled to the primary coil and supplies a high voltage to an ignition plug 55, and an ignition timing. A control circuit 52 for generating an ignition signal, a primary current interrupting element 51 for energizing or interrupting the primary current of the ignition coil 54 based on the ignition signal from the control circuit 52, and an ignition plug on the secondary coil side of the ignition coil 54 The configuration includes an ion current detection power supply circuit 56 and a current-voltage conversion circuit 58 that detect an ion current generated in the combustion chamber by the combustion operation based on the ignition operation 55.

  There is a method in which the ion current detection circuit is arranged as shown in FIG.

  In FIG. 3, the ion current detection circuit is arranged on the low voltage side of the secondary coil. When fuel is exploded and burned in the combustion chamber by the discharge operation of the spark plug 55, the ion current generated in the combustion chamber is the ion current. It is detected as a voltage output of the current-voltage conversion circuit 58 together with the current applied to the spark plug 55 by the detection circuit. Hereinafter, this circuit system will be referred to as a low pressure detection system.

  In FIG. 4, the ion current detection circuit is disposed on the high voltage output side of the secondary coil. When fuel is exploded and burned in the combustion chamber by the discharge operation of the spark plug 55, the ion current generated in the combustion chamber is A current output from the current detection circuit is detected as a voltage output of the current-voltage conversion circuit 58 together with the current applied to the spark plug 55. Hereinafter, this circuit system is referred to as a high voltage detection system.

  It is expected that the suitability of the combustion state can be determined based on the ion current thus detected. For example, it is expected that knocking can be eliminated and other combustion control can be performed.

  In an ionic current detection device for an internal combustion engine, the current ionic current detection circuit has individual package type semiconductors or electronic components such as resistors mounted on a substrate as shown in FIG. 5 and connected to a conductor pattern on a dedicated substrate by soldering. Yes. Therefore, there is a limit to circuit integration, and since there are a large number of component connection locations, it is inevitable that the failure rate of the solder joint due to thermal stress increases.

  Also, since the electronic components to be mounted are mounted in different packages, the circuit area is highly integrated, that is, an ion current detection circuit because of the mounting area and the area necessary for the board layout required to wire each element. However, there is a limit to the high integration, and this has become a barrier to market needs for cost reduction and size reduction.

  In the case of the low voltage detection method, when a load on the secondary coil output side, such as a spark plug, is short-circuited, a part of the secondary output energy is consumed by the ion current detection resistor 54. Depending on the ignition coil characteristics, a voltage drop of about 1 kV to 1.5 kV occurs. For this reason, an excessive reverse voltage is applied to the secondary coil discharge current diode 53, and the secondary coil discharge current diode 53 may break down the breakdown voltage.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ion current detection device for an internal combustion engine that is small in size and high in reliability.

  In FIG. 1 a, a diode array 1 composed of a constant voltage diode for an ion current detection power source and a secondary coil discharge current diode is ionized onto an ion current diode 4, an ion current detection resistor 5 and a ceramic substrate 3 by a C4 method. The power source capacitor of the current detection circuit and the current-voltage conversion circuit are mounted together with the IC 2 configured on the same semiconductor as the control circuit and the protection circuit of the primary current cutoff element.

  In FIG. 1b, a diode array 1 comprising a constant voltage diode for ion current detection power supply and a secondary coil discharge current diode is connected to an ion current diode 4, an ion current detection resistor 5 and an ion current detection on a ceramic substrate 3. The power supply capacitor of the circuit, the current-voltage conversion circuit are mounted together with the IC2 in which the control circuit and the protection circuit of the primary current cutoff element are configured on the same semiconductor, and the cathode of the constant voltage diode for the ion current detection power supply of the diode array The low voltage side of the secondary coil is connected using a wire bonding method.

  It is more effective to configure the ion current detection power supply circuit and the control circuit and protection circuit for the primary current interrupting element on the same semiconductor, or to further configure the primary current interrupting element on the same semiconductor.

  As a countermeasure when the secondary discharge current diode 11 is abnormal, the diode is configured so that when an excessive reverse voltage is applied, the PN junction is broken down to form a secondary coil current path generated in the ignition coil. By using a diode capable of using both characteristics, such as an avalanche diode, the breakdown of the secondary current discharge current diode can be prevented.

  Specifically, in claim 1, a primary coil whose primary current is on / off controlled by electronic control by a switching element, a secondary coil that is electromagnetically coupled to the primary coil and supplies a high voltage to a spark plug, An ion current detection device for an internal combustion engine having an ion current detection circuit for detecting an ion current generated in a combustion chamber by a combustion operation based on an ignition operation of a spark plug on the secondary coil side of the coil. According to claim 2, the ion current detection circuit or a part of the amplification circuit thereof, and the control circuit and the protection circuit of the primary current cutoff element are configured on the same semiconductor, and are configured on the same semiconductor. A control circuit and a protection circuit for the ion current detection circuit and the primary current interrupting element are mounted on the substrate by a C4 method using a bare chip.

In claim 3, the secondary coil discharge current diode constituting the ion current detection circuit is a diode using the reverse characteristics of the PN junction, and in claim 4, the ion detection power supply ZD constituting the ion current detection circuit and The secondary coil discharge current diode is formed on the same semiconductor and is mounted on the substrate by a bare chip by the C4 method. In claim 5, the ion detection power supply ZD and the secondary coil discharge current diode, which constitute the ion current detection circuit, are formed on the same semiconductor, mounted on the substrate with bare chips, and the wire bonding method is applied to the secondary coil. Connect with by.

  With the above configuration, it is possible to realize an ion current detection device for an internal combustion engine that is small in size and high in reliability.

  An embodiment of the present invention includes a primary coil in which a primary current is turned on / off by electronic control by a primary current interrupting element, a secondary coil that is electromagnetically coupled to the primary coil and supplies a high voltage to a spark plug, An ion current detection apparatus for an internal combustion engine, comprising: a detection circuit that detects an ion current generated in a combustion chamber by a combustion operation based on an ignition operation of a spark plug; and a coil case that includes the primary coil and the secondary coil. Specifically, an ion current detection circuit and a control circuit and a protection circuit for a primary current cut-off element are configured on the same substrate or the same semiconductor by the structure as shown in FIG. The area occupied by parts on the board is reduced, and the number of joints by solder or conductive adhesive is reduced. Specifically, the mounting component area is reduced by consolidating the constant voltage diode for the ion current detection power supply and the diode for the secondary discharge current as a diode array, and the conventional ion current detection circuit board is configured on a separate circuit board. The circuit is configured on a single substrate together with a primary current cutoff element control circuit, a protection circuit, and a current-voltage conversion circuit. That is, the ion current detection circuit board required in the conventional structure is not necessary, and at the same time, the connection with the control circuit board of the primary current interrupting element is not required. Specifically, in the conventional structure, the ion current detection power supply circuit uses an ion current detection circuit board composed of five surface mount components.

  The diode array composed of the constant voltage diode for the ion current detection power source and the secondary current diode of the ion current detection circuit of the present invention does not require a special semiconductor process and can be easily manufactured by a general semiconductor process. . The semiconductor structure of the diode array can be constituted not only by a bipolar structure but also by a semiconductor structure such as CMOS or BiCMOS.

  By applying the technology of the present invention as described above, an ion current detection device for an internal combustion engine that is highly reliable, small and light can be realized at low cost.

  As mentioned above, although embodiment of this invention was described, embodiment is not specifically limited to the said form. Needless to say, the ignition device can be used for any necessary engine, and can be appropriately enlarged or reduced in size according to the application, and can be performed by those skilled in the art based on the spirit of the present invention. It is also possible to carry out various modifications and improvements.

Diode array ion circuit structure Ignition device for diode array internal combustion engine Circuit diagram of conventional low-voltage detection type ion current detector Circuit diagram of conventional high-voltage detection type ion current detector Ion current detection circuit structure of a conventional low voltage detection type ion current detection device

Explanation of symbols

1 Diode array 2 IC
3 Ceramic substrate 4 Ion current diode 5 Ion current detection resistor 51 Primary current cut-off element 52 Control circuit 53 Battery power supply 54 Ignition coil 55 Ignition plug 56 Ion current detection power supply circuit 57 Ion current detection resistor 58 Current voltage conversion circuit 59 Ion Power supply circuit for signal waveforms

Claims (5)

A primary coil whose primary current is controlled to be turned on and off by electronic control by a switching element, a secondary coil that is electromagnetically coupled to the primary coil and supplies a high voltage to the spark plug, and the secondary coil side of the ignition coil is ignited An ion current detection circuit for an internal combustion engine having an ion current detection circuit for detecting an ion current generated in a combustion chamber by a combustion operation based on a plug ignition operation, characterized in that the ion current detection circuit is configured on the same semiconductor. An ionic current detection device for an internal combustion engine. The control circuit and protection circuit of the ionic current detection circuit or a part of the amplification circuit and the primary current cutoff element are configured on the same semiconductor, and the ionic current detection circuit and the primary current cutoff configured on the same semiconductor. An ion current detection device for an internal combustion engine, wherein the element control circuit and the protection circuit are bare chips and are mounted on a substrate by a C4 method. An ion current detection device for an internal combustion engine, wherein the secondary coil discharge current diode constituting the ion current detection circuit is a diode using a reverse direction characteristic of a PN junction. An ion for an internal combustion engine, characterized in that an ion detection power supply ZD and a secondary coil discharge current diode constituting an ion current detection circuit are formed on the same semiconductor and mounted on a substrate by a bare chip by a C4 method. Current detection device. The ion detection power supply ZD and the secondary coil discharge current diode, which constitute the ion current detection circuit, are configured on the same semiconductor, mounted on the substrate with a bare chip, and connected to the secondary coil by a wire bonding method. An ionic current detection device for an internal combustion engine, characterized in that

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