DE112017000858T5 - detonator - Google Patents

Abstract

An ignition device (1) includes a ignition switching element (2), a capacitor (3), a pre-drive switching element (5) and an off-DC circuit (4 _OFF ). The ignition switching element (2) is connected to a primary winding (11) of an ignition coil (10). The condenser (3) is connected to a control terminal (21) of the ignition switching element (2). The pre-drive switching element (5) is connected in parallel with the capacitor (3). The off-DC circuit (4 _OFF ) is electrically connected to the control terminal (21) and the capacitor (3). The off-DC circuit (4 _OFF ) discharges an electric charge stored at a DC current in the capacitor (3).

Description

Cross-reference to related application

The present application is based on Japanese application No. 2016-28248 filed Feb. 17, 2016, the disclosure of which is incorporated herein by reference.

Technical area

The present disclosure relates to an ignition device for ignition of a spark plug of an internal combustion engine.

State of the art

An ignition device for ignition to a spark plug of an internal combustion engine is known (refer to PTL 1, which is specified below), wherein the device comprises a Zündumschaltelement, which is connected to a primary winding of an ignition coil, and a pre-drive circuit is connected to a control terminal of the Zündumschaltelements includes. A secondary coil of the ignition coil is connected to the spark plug.

When ignition is caused to the spark plug, the ignition device rapidly turns off the ignition switching element using the pre-drive circuit. As a result, a primary current flowing through the primary winding is rapidly interrupted, and a high secondary voltage is generated at the secondary winding. This secondary voltage is used to cause ignition on the spark plug.

In addition, the igniter is configured to turn off the ignition switch while suppressing ignition of the spark plug when an abnormality occurs. For this purpose, the ignition device is provided with an RC circuit (see 16 ), which has a resistor and a capacitor. When any abnormality has occurred, the igniter slowly turns off the ignition switch by using a discharge of the capacitor of the RC circuit. Thus, the primary current is slowly interrupted and generation of the high secondary voltage is inhibited. This makes it possible to turn off the ignition switching element while suppressing ignition of a mixed gas caused by ignition on the spark plug when an abnormality occurs.

Further, in the above igniter using the RC circuit, the ignition switching element is slowly turned on when starting to make the primary current flow through the primary winding. Thus, the primary current starts to flow slowly, and generation of the high secondary voltage is inhibited, thereby suppressing ignition of the mixed gas by the spark plug.

Citation List

patent literature

PTL 1: JP 5517686 B

Summary of the invention

The above igniter uses the RC circuit when the primary current is interrupted upon occurrence of an abnormality (which is also referred to as a soft-off operation hereinafter), and therefore, the voltage applied to the control terminal of the ignition switching element (the hereinafter also referred to as a control voltage), exponentially. Thus, the time rate of change of the control voltage is relatively high and the rate of change of the primary current is relatively high. Therefore, a high secondary voltage can be generated and the spark plug cause ignition even though the soft-off operation is performed.

Further, it is desirable to apply a high control voltage to the control terminal when the ignition switching element is turned on, so that the ignition switching element can be operated with low loss in a saturated region. However, the rate of change of the control voltage according to the above igniter at the start of the soft-off operation tends to become high (see FIG 7 ), if the control voltage at start-up is set high because the control voltage drops exponentially when soft-off operation is performed. Therefore, the time rate of change of the primary current becomes high and it is likely that a high secondary voltage is generated. Thus, the spark plug may cause ignition although the soft-off operation is performed. For this reason, it is necessary that the control voltage is set low, and the loss of the ignition switching element tends to be high.

In addition, the above igniter uses the RC circuit when the ignition switching element is turned on (which is also referred to as a soft-on operation hereinafter), and therefore, the voltage applied to the control terminal of the ignition switching element (ie, the control voltage ), exponential. Thus, the time rate of change of the control Voltage is relatively high and the rate of change of the primary current is relatively high. Therefore, a high secondary voltage can be generated and the spark plug cause ignition, although the soft-on operation is performed.

Further, the threshold voltage of the ignition switching element has a manufacturing variation. In the above igniter, the rate of change in the timing of the control voltage tends to vary (cf. 13 ), when the control voltage reaches the threshold voltage, since the control voltage increases exponentially when a soft-on operation is performed, when the threshold voltage varies. As a result, the time rate of change of the primary current may become high depending on the variation in the threshold voltage, and high secondary voltage may be generated when soft-on operation is performed, resulting in the spark plug causing ignition.

It is an object of the present disclosure to provide an ignition device that is capable of further reducing or decreasing the secondary voltage generated when a soft switching operation is performed.

• ein Zündumschaltelement, das mit einer primären Wicklung der Zündspule verbunden ist;
• einen Kondensator, der mit einem Steuerungsanschluss des Zündumschaltelements verbunden ist;
• ein Pre-Drive-Umschaltelement, das parallel mit dem Kondensator verbunden ist;
• einen Pull-up-Widerstand, der mit einem Punkt, der zwischen dem Steuerungsanschluss und dem Kondensator liegt, und einer Stromquelle verbunden ist; und
• eine Off-Gleichstrom-Schaltung, die elektrisch mit dem Steuerungsanschluss und dem Kondensator verbunden ist und dazu konfiguriert ist, eine elektrische Ladung zu entladen, die bei einem Gleichstrom in dem Kondensator gespeichert ist.

A first aspect of the present disclosure is an ignition device for ignition to a spark plug connected to a secondary winding of an ignition coil, the device including:

• a Zündumschaltelement which is connected to a primary winding of the ignition coil;
• a capacitor connected to a control terminal of the ignition switching element;
• a pre-drive switching element connected in parallel with the capacitor;
• a pull-up resistor connected to a point located between the control terminal and the capacitor and a power source; and
• an off-DC circuit electrically connected to the control terminal and the capacitor and configured to discharge an electric charge stored at a direct current in the capacitor.

• ein Zündumschaltelement, das mit einer primären Wicklung der Zündspule verbunden ist;
• einen Kondensator, der mit einem Steuerungsanschluss des Zündumschaltelements verbunden ist;
• ein Pre-Drive-Umschaltelement, das parallel mit dem Kondensator verbunden ist; und
• eine On-Gleichstrom-Schaltung, die elektrisch mit dem Steuerungsanschluss und dem Kondensator verbunden ist und dazu konfiguriert ist, den Kondensator bei einem Gleichstrom zu laden.

A second aspect of the present disclosure is an ignition device for ignition to a spark plug connected to a secondary winding of an ignition coil, the device including:

• a Zündumschaltelement which is connected to a primary winding of the ignition coil;
• a capacitor connected to a control terminal of the ignition switching element;
• a pre-drive switching element connected in parallel with the capacitor; and
• an on-dc circuit electrically connected to the control terminal and the capacitor and configured to charge the capacitor at a dc current.

The ignition device according to the first aspect or embodiment includes the off-DC circuit.

As a result, it is possible to further reduce the secondary voltage generated when soft-off operation is performed and to further reduce a variation in the secondary voltage. That is, since the off-DC circuit discharges the capacitor at a DC current, the voltage of the capacitor, that is, the voltage applied to the control terminal of the ignition switching element can be linearly lowered. Thus, as compared with a conventional case where the voltage applied to the control terminal is exponentially reduced by using an RC circuit, a rate of change of the primary current can be made constant and small, and the secondary voltage applied to the secondary winding is generated can be reduced. Therefore, it is possible to more effectively and stably suppress ignition of the spark plug when the soft-off operation is performed.

Further, the igniter can make a rate of change of the control voltage at the start of the soft-off operation constant and small. As a result, even if the control voltage is high, the rate of change of the control voltage at the start of the soft-off operation can be reduced when the ignition switching element is turned on. Thus, the rate of change of the primary current at this time can be reduced and the secondary voltage can be reduced. Accordingly, it is possible to set the control voltage applied at power-on high and at the same time to inhibit spark plug ignition at the time of soft-off operation, and thus the ignition switching element can operate in a saturated region become. Therefore, the loss of the ignition switching element can be reduced.

In addition, the ignition device according to the second aspect or embodiment includes the on-DC circuit.

As a result, the capacitor can be charged at a DC current when the soft-on operation is performed. Thus, the voltage of the capacitor, that is, the voltage applied to the control terminal of the ignition switching element can be increased linearly. Thus, as compared with a conventional case where the voltage applied to the control terminal is exponentially increased by using an RC circuit, the rate of change of the primary current can be made constant and small, and the secondary voltage generated at the secondary winding is generated can be reduced. Therefore, it is possible to more effectively and stably suppress ignition of the spark plug when the soft-on operation is performed.

Further, the ignition device can constantly make the rate of change of the timing of the control voltage when the soft-on operation is performed. Accordingly, the time change rate of the control voltage at the time when the control voltage reaches the threshold voltage when the soft-on operation is performed may be constant, even if there is a variation in the threshold voltage of the ignition switching element. Thus, it is possible to suppress a variation in the rate of change of the primary current at that time, and generation of a high secondary voltage can be inhibited. Therefore, it is possible to more effectively suppress ignition of the spark plug when the soft-on operation is performed, even if there is a variation in the threshold voltage of the ignition switching element.

As described above, according to the present aspect, it is possible to provide an ignition device capable of further reducing a secondary voltage generated when a soft switching operation is performed.

list of figures

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings.

• 1 ein Schaltungsdiagramm einer Zündvorrichtung gemäß einer ersten Ausführungsform in einem Zustand, in welchem ein Zündumschaltelement ausgeschaltet ist.
• 2 ein Schaltungsdiagramm der Zündvorrichtung gemäß der ersten Ausführungsform, wenn ein elektrischer Leitungsbetrieb einer ersten Wicklung durchgeführt wird.
• 3 ein Schaltungsdiagramm der Zündvorrichtung gemäß der ersten Ausführungsform, wenn ein Zündbetrieb durchgeführt wird.
• 4 ein Schaltungsdiagramm der Zündvorrichtung gemäß der ersten Ausführungsform, wenn ein Soft-Off-Betrieb durchgeführt wird.
• 5 ein Timing-Diagramm der Zündvorrichtung gemäß der ersten Ausführungsform, wenn ein Zündbetrieb wiederholt wird.
• 6 ein Timing-Diagramm der Zündvorrichtung gemäß der ersten Ausführungsform, wenn für eine bestimmte Zeitspanne keine Zündanweisung erteilt worden ist.
• 7 einen Graphen, der zusammen mit überlagerten Kurvenverläufen dieser, wenn unter Verwendung einer RC-Schaltung der Soft-Off-Betrieb durchgeführt wird, Kurvenverläufe einer Gatespannung, eines primären Stroms und einer sekundären Spannung zeigt, wenn unter Verwendung einer Off-Gleichstrom-Schaltung gemäß der ersten Ausführungsform der Soft-Off-Betrieb durchgeführt wird.
• 8 ein Querschnittsdiagramm der Zündvorrichtung gemäß der ersten Ausführungsform.
• 9 ein Schaltungsdiagramm einer Zündvorrichtung gemäß einer zweiten Ausführungsform.
• 10 ein Schaltungsdiagramm der Zündvorrichtung gemäß der zweiten Ausführungsform, wenn ein Soft-On-Betrieb durchgeführt wird.
• 11 ein Schaltungsdiagramm der Zündvorrichtung gemäß der zweiten Ausführungsform, wenn ein Zündbetrieb durchgeführt wird.
• 12 ein Schaltungsdiagramm der Zündvorrichtung gemäß der zweiten Ausführungsform, wenn ein Soft-Off-Betrieb durchgeführt wird.
• 13 einen Graphen, der zusammen mit überlagerten Kurvenverläufen dieser, wenn unter Verwendung einer RC-Schaltung der Soft-On-Betrieb durchgeführt wird, Kurvenverläufe einer Gatespannung, eines primären Stroms und einer sekundären Spannung zeigt, wenn unter Verwendung einer On-Gleichstrom-Schaltung gemäß der zweiten Ausführungsform der Soft-On-Betrieb durchgeführt wird.
• 14 einen Graphen, der eine Variation hinsichtlich einer Anstiegsrate der Gatespannung und eine Variation hinsichtlich einer Schwellenspannung des Zündumschaltelements gemäß der zweiten Ausführungsform zeigt.
• 15 ein Schaltungsdiagramm einer Zündvorrichtung gemäß einer dritten Ausführungsform.
• 16 ein Schaltungsdiagramm einer Zündvorrichtung gemäß einem Vergleichsbeispiel.
• 17 einen Graphen, der eine Variation hinsichtlich einer Anstiegsrate einer Gatespannung und eine Variation hinsichtlich einer Schwellenspannung eines Zündumschaltelements gemäß einem Vergleichsbeispiel zeigt.

It shows / show:

• 1 a circuit diagram of an ignition device according to a first embodiment in a state in which a Zündumschaltelement is turned off.
• 2 a circuit diagram of the ignition device according to the first embodiment, when an electrical line operation of a first winding is performed.
• 3 a circuit diagram of the ignition device according to the first embodiment, when an ignition operation is performed.
• 4 a circuit diagram of the ignition device according to the first embodiment, when a soft-off operation is performed.
• 5 a timing diagram of the ignition device according to the first embodiment, when an ignition operation is repeated.
• 6 a timing diagram of the ignition device according to the first embodiment, when no ignition instruction has been issued for a certain period of time.
• 7 FIG. 4 is a graph showing, along with superimposed waveforms thereof when using soft-off operation using an RC circuit, waveforms of a gate voltage, a primary current, and a secondary voltage when using an off-DC circuit according to FIG first embodiment, the soft-off operation is performed.
• 8th a cross-sectional diagram of the ignition device according to the first embodiment.
• 9 a circuit diagram of an ignition device according to a second embodiment.
• 10 a circuit diagram of the ignition device according to the second embodiment, when a soft-on operation is performed.
• 11 a circuit diagram of the ignition device according to the second embodiment, when an ignition operation is performed.
• 12 a circuit diagram of the ignition device according to the second embodiment, when a soft-off operation is performed.
• 13 FIG. 4 is a graph showing, along with superimposed waveforms thereof, when performing soft-on operation using an RC circuit, waveforms of a gate voltage, a primary current and a secondary voltage when using an on-DC circuit according to FIG second embodiment, the soft-on operation is performed.
• 14 a graph showing a variation in a rate of increase of the gate voltage and shows a variation in a threshold voltage of the ignition switching element according to the second embodiment.
• 15 a circuit diagram of an ignition device according to a third embodiment.
• 16 a circuit diagram of an ignition device according to a comparative example.
• 17 FIG. 12 is a graph showing a variation in a rate of rise of a gate voltage and a variation in a threshold voltage of a firing switching element according to a comparative example.

Description of the embodiments

The ignition device may be an on-vehicle ignition device for ignition on a spark plug of an engine in a vehicle.

First embodiment

With reference to the 1-8 an embodiment according to the above igniter will be described. The ignition device 1 The embodiment is for ignition on a spark plug 13 used that with a secondary winding 12 an ignition coil 10 connected is. As in 1 is shown includes the ignition device 1 a Zündumschaltelement 2 , a capacitor 3 , a pre-drive switching element 5 , a pull-up resistor 19 and an off-DC circuit 4 _OFF .

One end of a primary winding 11 the ignition coil 10 is with a power supply 18 connected and the other end is connected to the collector of Zündumschaltelements 2 connected. The emitter of Zündumschaltelements 2 is connected to the mass.

The capacitor 3 is with a control connection 21 the Zündumschaltelements 2 connected and one end of it is connected to the ground.

The pre-drive switching element 5 is in parallel with the capacitor 3 connected.

The pull-up resistor 19 is connected to a point between the control terminal 21 and the capacitor 3 lies, and a power source 14 connected. The power source 14 is a low-voltage power supply, such as a lead storage battery.

The off-DC circuit 4 _OFF is electrically connected to the control terminal 21 and the capacitor 3 connected. As in 4 is shown, the off-DC circuit 4 _OFF is configured to discharge an electric charge that is at a DC current I _3D in the capacitor 3 is stored.

The ignition device 1 The present embodiment is an on-vehicle ignition device for ignition of a spark plug 13 a machine in a vehicle.

Next, an operation of the ignition device 1 described, which is performed when an ignition on the spark plug 13 is caused. As in 1 is shown, the igniter switches 1 first the ignition switching element 2 off when a power supply is turned on. At this time, the electrical potential of a signal line 49 (ie point B) of the off-DC circuit 4 _{OFF set} to L and the electrical potential of a control terminal 59 (ie, point A) of the pre-drive switching element 5 is set to H. In this way, the pre-drive switching element 5 turned on and a current I ₁₉ flows from the power source 14 through the pull-up resistor 19 and the pre-drive switching element 5 to the crowd. Therefore, in the condenser 3 no charge accumulated and the voltage of the capacitor 3 does not rise. Thus, the voltage of the control terminal reaches 21 a threshold voltage is not and the Zündumschaltelement 2 is switched off.

After that, the igniter switches 1 in response to a low signal of an ignition operation command signal, which is sent from an engine control unit, which is not shown in detail, or the like, the pre-drive switching element 5 out. Thus, the capacitor becomes 3 charged by the current I ₁₉ flowing through the pull-up resistor 19, the Zündumschaltelement 2 is turned on and the primary current i ₁ begins, through the primary winding 11 to flow, as in 2 will be shown. At this time, due to the charging characteristics of the pull-up resistor 19 and the capacitor increases 3 the voltage connected to the control port 21 is created, gradually. As a result, the ignition switching element becomes 2 slowly turned on and the primary current i ₁ begins, gradually through the primary winding 11 to flow. As a result, the primary winding 11 the primary current i _{1 is} supplied while igniting the spark plug 13 is prevented.

After that, the pre-drive switching element 5 turned on and the capacitor 3 is discharged quickly when the point A is set to H, as in 3 will be shown. Thus, the ignition switching element becomes 2 suddenly switched off and the primary current i ₁ is suddenly switched off. As a result, a high secondary voltage V _{2 is applied} to the secondary winding 12 generated, a spark discharge S is at the spark plug 13 is generated and a mixed gas in the cylinder is ignited.

Further, the soft-off operation is performed if some abnormality occurs after the primary current i _{1 is} supplied, as in FIG 2 and the H signal of the point A for turning on the pre-drive switching element 5 is not entered for a certain period of time. That is, the ignition switching element 2 is turned off while on the spark plug 13 an ignition is prevented. In the case that the soft-off operation is performed as in 4 is shown, the point B is set to H while the point A is held at L. In this way, the off-DC circuit 4 _{OFF is turned} on and a direct current flows, which is set by circuit constants. As a result, the electric charge that is in the capacitor 3 is stored at the DC I _3D discharge and the voltage of the capacitor 3 decreases with a certain gradient. Thus, the voltage drops to the control port 21 is applied gradually with a constant gradient and the primary current i ₁ gradually decreases with a constant rate of change. Therefore, the secondary voltage V ₂ is suppressed compared with the conventional case in which the primary current i _{1 is} changed exponentially, and ignition on the spark plug 13 can be stopped.

Next, referring to 5 and 6 Timing diagrams of the igniter 1 to be discribed. 5 shows a timing diagram of the ignition device 1 when an ignition is repeated at the machine, and 6 shows a timing diagram of the same when a soft-off operation is performed when an abnormality occurs. The point A in the 5 and 6 is the control connection 59 of the pre-drive switching element 5 , The point A receives a signal for controlling an electric wire and interrupting an electric wire of the primary winding 11 when the ignition operation is performed. Point B is the signal line 49 which is connected to the control terminal of the off-DC circuit 4 _OFF . Point C is the control port 21 the Zündumschaltelements 2 and point D is the collector 29 the Zündumschaltelements 2 ,

As in 5 is shown, first the electrical line operation to the primary coil 11 performed when the machine is ignited. That is, the point B is set to L, and at the time t1, the point A is switched from H to L. In this way, the pre-drive switching element 5 turned off and the current I ₁₉ flows from the power source 14 gradually to the pull-up resistor 19, and the capacitor 3 is slowly loaded with an RC time constant. Therefore, the voltage of the capacitor increases 3 gradually, the Zündumschaltelement 2 is gradually turned on and the primary current i ₁ flows through the primary winding 11 ,

After that, the pre-drive switching element 5 turned on and the electrical charge in the capacitor 3 is stored, is discharged quickly when the point A is set to H at time t2. Thus, the ignition switching element becomes 2 switched off and the primary current i ₁ is switched off quickly. Consequently, at the primary winding 11 generates a high primary voltage V ₁ . The result is also a high secondary voltage V2 at the secondary winding 12 generates a spark discharge S is at the spark plug 13 generated and the mixed gas in the machine is ignited.

Further, the soft-off operation is performed if some abnormality occurs after changing the point A to L at time t3, as in FIG 6 is shown and no instruction is entered for a certain period of time, at the spark plug 13 to cause an ignition. That is, the point B is set to H at the time t4 while the point A of the ignition signal is kept at L, that is, the pre-drive switching element 5 kept off. In this way, the off-DC circuit 4 is turned _OFF and the electrical charge in the capacitor 3 stored is discharged at a direct current. Thus, the voltage of the point C gradually decreases at a constant rate of change, and the primary current i ₁ gradually decreases. Thus, the primary voltage V1 and the secondary voltage V2 are suppressed, and the Zündumschaltelement 2 Can be turned off while on the spark plug 13 an ignition is prevented.

7 shows curves of a gate voltage V _g , a primary current i ₁ and a secondary voltage V ₂ , when using the off-DC circuit 4 _OFF, the soft-off on the Zündumschaltelement 2 is carried out. In addition, in 7 Curves shown in a superimposed manner when using an RC circuit (cf. 16 ) the soft-off on the Zündumschaltelement 2 is performed as in a conventional art.

When the capacitor 3 is discharged at a direct current using the off-DC circuit 4 _OFF , the voltage of the capacitor decreases 3 linear. Accordingly, in the case where the off-DC circuit 4 _{OFF is} used after the soft-off has started at time t4, the voltage of the capacitor decreases 3 that is, the gate voltage V _{g of} the ignition switching element 2 , linear, as in 7 will be shown. Consequently the primary current i ₁ also decreases linearly. As a result, the time change rate di ₁ / dt of the primary current i ₁ becomes constant and can also be set to a relatively small value, and accordingly, the generated secondary voltage V ₂ also becomes relatively low. Thus, ignition of the mixed gas can be inhibited since it is less likely to be affected by the voltage passing through the spark plug 13 is generated, sparks fly, and that the energy generated is low, even if there is a flying sparks.

In contrast, in the case where, as in the conventional art, an RC circuit is used after the soft-off has started at time t4, the gate voltage V _{g of} the ignition switching element decreases 2 exponentially. As a result, the primary current i ₁ also decreases exponentially. Thus, the time rate of change di ₁ / dt of the primary current i _{1 is} relatively large, and it is likely that a high secondary voltage V _{2 is} generated. Therefore, due to the secondary voltage V _{2 occurs} at the spark plug 13 the spark discharge S on and the mixed gas can be ignited.

Next, the circuit configuration of the off-DC circuit 4 _{OFF will be} described. As in 1 is shown, the off-DC circuit 4 _OFF includes a switching transistor 40 and a DC transistor 41 , The switching transistor 40 is provided to switch between conduction and interruption of the current. The DC transistor 41 is provided so that this a current I ₄₀ (see 4 ) holding at a constant value through the switching transistor 40 flows.

In this embodiment, an N-channel MOSFET becomes the switching transistor 40 used and an NPN-type bipolar transistor is called the DC transistor 41 used. The source 401 of the switching transistor 40 is with the base 413 of the DC transistor 41 connected and is via a second resistor 43 to set a current also connected to ground. The drain 402 of the switching transistor 40 is with the capacitor 3 connected. The emitter 411 of the DC transistor 41 is over a first resistance 42 connected to the mass. The collector 412 of the DC transistor 41 is with the gate 403 of the switching transistor 40 connected.

As in 4 is shown, the switching transistor 40 turned on and the current I ₄₀ flows when the potential of the gate 403 is set to H. The current I ₄₀ is the sum of the discharge current I _{3D of} the capacitor 3 and the current I ₁₉ , starting from the power supply 14 flows via the pull-up resistor 19. At a connection point 414 the current I _{40 is converted} into a current I ₄₃ passing through the second resistor 43 flows, and the base current I _{41b of} the DC transistor 41 divided. The base current I _41b correlates with a collector current I _{41c of} the DC transistor 41 and a coefficient 1 / h _fe . The sum of the base current I _41b and the collector current I _41c becomes the current I ₄₂ passing through the first resistor 42 flows.

The voltage drop from the connection point 414 to the mass is at the side of the first resistor 42 and the side of the second resistor 43 equal. That is, the tension of the base 413 and the current I ₄₃ passing through the second resistor 43 flows as well as the base current I _41b are determined so that the product of the resistance of the second resistor 43 and the current I ₄₃ flowing therethrough is equal to the sum of the product of the resistance of the first resistor 42 and the current I ₄₂ flowing therethrough, and the voltage Vbe between the base and the emitter of the DC transistor 41 is. Therefore, the sum (current I ₄₀ ) of the currents I ₄₃ and I _{41b is} constant. The current I ₄₀ is the sum of the current I ₁₉ flowing through the pull-up resistor 19, and the discharge current I of the capacitor _3D 3 , and the current I ₁₉ is constant. Therefore, the discharge current I _3D becomes constant.

Since the current I ₄₀ according to the resistance values of the first resistor 42 and the second resistor 43 as described above can be set arbitrarily, even if a high voltage to the control terminal 21 the Zündumschaltelements 2 is applied, it is also possible to set the value of the current I ₄₀ in a simple manner so that the time rate of change di ₁ / dt of the primary current i _{1 is} constant and small. Thus, the soft-off operation can be reliably performed from this state, even if a high voltage is applied to the control terminal 21 is applied and the Zündumschaltelement 2 is located in a saturated area. Consequently, the Zündumschaltelement 2 be operated in the saturated region when a normal ignition operation is performed. That is, the ignition switching element 2 can be placed in the saturated region and the loss of Zündumschaltelements 2 due to the primary current i ₁ can be suppressed if the primary winding 11 the primary current i _{1 is} supplied by the Zündumschaltelement 2 (see 2 ) is turned on.

Next, referring to 8th the three-dimensional structure of the ignition device 1 to be discribed. As in 8th is shown, the off-DC circuit 4 _OFF and the pre-drive switching element 5 in this embodiment, in a single semiconductor chip 8th educated. Furthermore, the ignition device includes 1 a control unit 7 for controlling on / off of the off-DC circuit 4 _OFF and the pre-drive switching element 5 , The control unit 7 , the semiconductor chip 8th and the ignition switching element 2 are with a sealing component 80 sealed to form a single component.

The control unit 7 , the semiconductor chip 8th and the ignition switching element 2 are on a heat sink plate 81 assembled. There is also a connection 82 for an electrical connection with an external device from the sealing component 80 out.

Next, the functions and effects of the present embodiment will be described. As in 1 is shown includes the ignition device 1 In the present embodiment, the off-DC circuit 4 _OFF . The off-DC circuit 4 _OFF is configured to discharge an electric charge of the capacitor 3 connected to the control port 21 is connected to allow for a direct current.

As a result, it is possible to further reduce the secondary voltage V ₂ generated when the soft-off operation is performed. That is, since the off-DC circuit 4 _OFF the capacitor 3 can discharge at a direct current, as in 7 can be shown, the voltage of the capacitor 3 , that is, the voltage V _{g applied} to the control terminal 21 the Zündumschaltelements 2 is applied, be reduced linearly. Thus, as compared with the conventional case in which the voltage applied to the control terminal is exponentially reduced by using an RC circuit, the time rate of change di ₁ / dt of the primary current i _{1 can be made} constant and small, and FIG secondary voltage V ₂ , which is at the secondary winding 12 is generated can be reduced. As a result, it is possible to ignite the spark plug 13 more effectively inhibit when performing soft-off operation.

As described above, according to the present embodiment, it is possible to provide an ignition device capable of further reducing the secondary voltage generated when a soft switching operation is performed.

In the present embodiment, an IGBT becomes the ignition switching element 2 used as in 1 is shown, but the present invention is not limited thereto, and a MOSFET or a bipolar transistor may be used.

Further, in the present embodiment, the semiconductor chip 8th on which the off-DC circuit 4 _OFF and the pre-drive switching element 5 are trained, as in 8th is shown, the control unit 7 and the ignition switching element 2 sealed together to form a single component, but the present invention is not limited thereto. That is, these may be so-called discrete components in which these components are separated. In addition, the off-DC circuit 4 _{OFF is} not limited to that disclosed in the present embodiment, and other known circuit configurations or ICs thereof may be used.

In the embodiments described below, those reference numerals used in the drawings designate the same reference numerals as those used in the first embodiment, components or the like similar to those of the first embodiment, unless otherwise specified.

Second embodiment

The present embodiment is an example in which the circuit configuration of the ignition device 1 is changed. As in 9 is shown includes the ignition device 1 the present invention, the Zündumschaltelement 2 that with the primary winding 11 the ignition coil 10 connected to the condenser 3 , the pre-drive switching element 5 and an on-DC circuit 4 _ON .

As in 10 is shown, the on-dc circuit 4 is _ON to the control terminal 21 and the capacitor 3 connected and configured to the capacitor 3 to charge at a direct current I _3C . As with the off-DC circuit 4 _OFF , the on-DC circuit 4 _ON includes the switching transistor 40 and the DC transistor 41 , The source of the switching transistor 40 is about a fourth resistance 45 with the power source 14 connected. The emitter of the DC transistor 41 is about a third resistance 44 with the power source 14 connected.

The DC I _3C , through the switching transistor 40 flows, charges the capacitor 3 , The current I _3C is a current consisting of a current I ₄₅ passing through the fourth resistor 45 which flows with a base current I _{41b of} the DC transistor 41 at a connection point 415 combined results. The base current I _41b correlates with the collector current I _{41c of} the DC transistor 41 and the coefficient 1 / h _fe , and the sum of the base current I _41b and the collector current I _41c forms a current I ₄₄ off, by the third resistance 44 flows. The tension of the base 413 and the current I ₄₅ passing through the fourth resistor 45 and the base current I _41b are determined so that the product of the resistance of the fourth resistor 45 and the current I ₄₅ flowing therethrough is equal to the sum of the product of the resistance of the third resistor 44 and the current I ₄₄ flowing therethrough, and a voltage V _be between the base and the emitter of the DC transistor 41 is. As a result, the sum (current I _3C ) of the currents I ₄₅ and I _{41b becomes} constant.

Since the current I _3C according to the resistance values of the third resistor 44 and the fourth resistance 45 as described above can be set arbitrarily, even if a high voltage to the control terminal 21 is applied, it is possible to easily set the value of the current I _3C so that the time change rate di ₁ / dt of the primary current i _{1 is} constant and small. Accordingly, it is possible to gradually apply a high voltage to the control terminal 21 to apply when the primary current i ₁ begins to flow, and the Zündumschaltelement 2 can be put into the saturated area. Therefore, the loss of Zündumschaltelements 2 be suppressed due to the primary current i ₁ .

As in the first embodiment, the ignition device includes 1 Further, in the present embodiment, the off-DC circuit 4 _OFF . The off-DC circuit 4 _OFF is connected to the control terminal 21 and the capacitor 3 connected and configured to charge the electrical charge in the capacitor 3 is stored to discharge at a DC I _3D .

Next, the operation of the ignition device 1 described, which is performed when attached to the spark plug 13 an ignition is caused. As in 10 is shown, performs the ignition device 1 first the soft-on operation. That is, the primary winding 11 the primary current i _{1 is} supplied by the Zündumschaltelement 2 is slowly turned on at a direct current while the ignition is on the spark plug 13 is prevented at the start of an electrical line. At this time, both point A and point B are set to L as in 10 will be shown. In this way, the on-current circuit 4 is turned _ON and the soft off-DC circuit 4 is turned _OFF, and the capacitor 3 is charged with a direct current I _3C . As a result, the voltage of the capacitor increases 3 that is the voltage of the control connection 21 , linear. Thus, it is possible to make the time change rate di ₁ / dt of the primary current i ₁ constant and small, and the secondary voltage V ₂ can be reduced. Therefore, it is possible to supply the primary current i ₁ while igniting the spark plug 13 is prevented.

Thereafter, the point A is changed from L to H, while point B is kept at L as in 11 will be shown. In this way, the pre-drive switching element 5 turned on and the electrical charge in the capacitor 3 is stored by the pre-drive switching element 5 discharged quickly. As a result, the primary current i _{1 is} suddenly interrupted and at the primary winding 12 a high primary voltage V _{2 is} generated. Therefore occurs at the spark plug 13 the spark discharge S on.

Further, the point B is changed to H while the point A is kept at L when, for a certain period of time, starting from the state of 10 no signal to ignite the spark plug 13 is entered as in 12 will be shown. In this way, the on-dc circuit 4 is turned off _ON , resulting in that the current I _3C stops, and the off-dc circuit 4 _OFF is turned on, allowing the dc I _3D to flow. As a result, the capacitor becomes 3 at a DC I _3D discharge and the voltage of the capacitor 3 that is the voltage of the control connection 21 , decreases linearly. Thus, it is possible to make the time change rate di ₁ / dt of the primary current i ₁ constant and small, and the secondary voltage V ₂ can be reduced. Accordingly, the Zündumschaltelement 2 be turned off while on the spark plug 13 an ignition is prevented.

Next shows 13 Curves of a gate voltage V _g , a primary current i ₁ and a secondary voltage V ₂ when, using the on-DC circuit 4 _ON, the soft-on on the Zündumschaltelement 2 is carried out. In addition, in 13 Curves shown in a superimposed manner when using the RC circuit (cf. 16 ) the soft-on on the Zündumschaltelement 2 is performed as in a conventional art.

As in 13 is shown, the Zündumschaltelement 2 is turned on and the primary current i ₁ starts to flow when the gate voltage V _g rises and exceeds the threshold voltage Vth. Further, as described above, the voltage of the capacitor increases 3 linear because of the capacitor 3 is charged at a DC current when the on-DC circuit 4 _ON is used. Therefore, in the case where the on-direct-current circuit 4 _{ON is} used after the soft-on has started at the time t1, the voltage of the capacitor increases 3 that is, the gate voltage V _{g of} the ignition switching element 2 , linear on. Thus, can the primary current i ₁ can be increased linearly. Thus, it is possible to make the time change rate di ₁ / dt of the primary current i ₁ constant and small, and the generated secondary voltage V ₂ can be reduced. Therefore, it is possible to cause the spark discharge S on the spark plug to occur 13 to prevent.

In contrast, in the case where, as in the conventional art, an RC circuit is used after the soft-on has started at time t1, the gate voltage V _{g of} the ignition switching element increases 2 exponentially. As a result, the primary current i ₁ also increases exponentially. Thus, the time rate of change di ₁ / dt of the primary current i _{1 is} relatively large and a high secondary voltage V _{2 is} generated. Therefore, due to the secondary voltage V ₂ at the spark plug 13 the spark discharge S occur.

Meanwhile, the switching transistor 40p On the DC circuit 4 _ON and the switching transistor 40n the off-DC circuit 4 _{OFF connected} in series, as in 9 will be shown. Furthermore, the control connections (that is, the gates 403 ) of the two switching transistors 40p and 40n with a common signal line 49 connected. In addition, the two switching transistors 40p and 40n Complementary transistors, that is, one is in an off state while the other is in an on state, as in FIGS 10 and 12 will be shown.

Next, the functions and effects of the present embodiment will be described. As in 10 is shown includes the ignition device 1 In the present embodiment, the on-direct current circuit 4 _ON .

As a result, it is possible to perform the soft-on operation, ie, the operation for starting the supply of the primary current i ₁ , while igniting the spark plug 13 is prevented to perform. That means that the capacitor 3 in the present embodiment, can be charged at a DC current I _3C because the on-DC circuit 4 _{ON is} provided. Thus, the voltage of the capacitor 3 that is the voltage connected to the control port 21 the Zündumschaltelements 2 is created, be increased linearly. Thus, as compared with the conventional case where the voltage applied to the control terminal is exponentially increased by using an RC circuit, the time change rate di ₁ / dt of the primary current i _{1 can be made} constant and small, and FIG secondary voltage V ₂ , which is at the secondary winding 12 is generated can be reduced. Therefore, it is possible to inhibit ignition of the spark plug when the soft-on operation is performed.

Further, the variation in the secondary voltage V ₂ can be reduced by using the on-on-circuit 4 _ON , as in the present embodiment, even if, due to a manufacturing variation, a variation in the threshold voltage Vth of the ignition switching element 2 or the like. That is, a variation in the threshold voltage Vth of the ignition switching element 2 exists, as in 17 will be shown. In addition, due to a manufacturing variation in the resistance R and the capacitor C included in the RC circuit, there will be a variation in the RC time constant as well as the rate of increase of the gate voltage V _g when using the RC circuit. On-operation is performed. The curve L3 shows the case where the rate of increase is fastest and the curve L4 shows the case where the rate of increase is slowest. Thus, the ignition switching element becomes 2 for example at a relatively early time T11 when the threshold voltage V _{th is} low and the rate of rise of the gate voltage V _{g is} high (that is, in the case of the curve) L3 ). In addition, the rate of change of time dV _g / dt of the gate voltage V _g at the time T11 high and the time rate of change di ₁ / dt of the primary current i ₁ is also high, as the gate voltage V _g increases exponentially. Thus, it is likely that a particularly high secondary voltage V _{2 is} generated. Further, the ignition switching element becomes 2 at a relatively late time T12 when the threshold voltage V _{th is} high and the rate of rise of the gate voltage V _{g is} low (that is, in the case of the curve L4 ). At this time, since the time change rate dV _g / dt of the gate voltage V _{g is} low, the secondary voltage V ₂ becomes relatively low.

As described above, in the case where using the RC circuit, the soft-on operation is performed when there is variation in the threshold voltage Vth and the RC time constant, and this causes a variation in the time to which between T11 and T12 the ignition switching element 2 is turned on, probably that the voltage V ₂ varies greatly. Therefore, there will be a need to design the circuit in consideration of the case where the highest secondary voltage V _{2 is} generated, which makes the circuit design difficult.

In contrast, the variation in the secondary voltage V ₂ can be reduced by using the on-on-circuit 4 _ON , as in the present embodiment, even if a variation in the threshold voltage Vth of the ignition switching element 2 or the like. That is, due to the manufacturing variation of the capacitor 3 a Variation in the rate of rise of the gate voltage V _{g will} be present when the on-DC circuit 4 _ON is used, as in 14 will be shown. The line L1 shows the case where the rate of increase is fastest and the line L2 shows the case where the rate of increase is slowest. Thus, the ignition switching element becomes 2 at a relatively early age t11 when the threshold voltage V _{th is} low and the rate of rise of the gate voltage V _{g is} high (that is, in the case of the line L1 ). Further, the ignition switching element becomes 2 at a relatively late time t12 when the threshold voltage V _{th is} high and the rate of rise of the gate voltage V _{g is} low (that is, in the case of the line L2 ). In the present embodiment, the gate voltage V _{g increases} linearly as the capacitor 3 is charged at a direct current. Thus, the time rate of change dV _g / dt of the gate voltage V _g at the threshold will not vary even if the threshold of the ignition switching element 2 varies between V _th 1 and V _th 2. Thus, the time rate of change di ₁ / dt of the primary current i _{1 will} also not vary, and the variation in the primary voltage V ₁ generated in response to a current change may be inhibited. Therefore, the variation in the secondary voltage V _{2 can} also be suppressed, and the circuit design of the igniter 1 can be done in a simple way.

As in 10 is shown includes the ignition device 1 the present embodiment, further, both the on-DC circuit 4 _ON and the off-DC circuit 4 _OFF. Therefore, both the soft-on operation and the soft-off operation can be performed.

As in 10 is shown, the on-DC circuit 4 _ON and the off-DC circuit 4 _OFF contain the present embodiment further respectively to the switching transistor 40 ( 40p . 40n ) for switching between a line and interrupting the current I. The control terminals (that is, the gates 403 ) of the two switching transistors 40 are with the common signal line 49 connected. The two switching transistors 40 are complementary transistors and one of them is in an off state while the other is in an on state.

Thus, it is using a signal line 49 possible between the case in which only the on-direct current circuit 4 _{ON of} the two DC circuits 4 _ON and 4 _OFF, a current is supplied (see 10 ), and the case where only the off-DC circuit 4 _OFF, a current is supplied (see 12 ), to switch. Therefore, the circuit configuration of the ignition device 1 be simplified.

In addition, the embodiment has a similar configuration as well as similar functions and effects as those of the first embodiment.

Third embodiment

The present embodiment is an example in which the circuit configuration of the ignition device 1 is changed. As in 15 is shown includes the ignition device 1 the present invention, the Zündumschaltelement 2 that with the primary winding 11 the ignition coil 10 connected to the condenser 3 , the pre-drive switching element 5 and the on-dc circuit 4 _ON . In the present embodiment, the off-DC circuit 4 _{OFF is} not provided.

In this embodiment, the pre-drive switching element 5 turned off and the switching transistor 40 is turned on when the soft-on operation is performed. In this way, the on-direct current circuit 4 _ON charges the capacitor 3 at a direct current I and the voltage of the capacitor 3 that is the voltage connected to the control port 21 the Zündumschaltelements 2 is created is increased linearly. As a result, the rate of change of the primary current i _{1 will be} constant and small. Thus, an ignition on the spark plug 13 prevented.

To ignite the spark plug 13 becomes the pre-drive switching element 5 turned on. This will cause an electrical charge in the capacitor 3 is stored, quickly discharged and the Zündumschaltelement 2 is switched off quickly. As a result, the primary current i _{1 is} rapidly turned off, a high secondary voltage V ₂ is generated and at the spark plug 13 an ignition is caused.

In addition, the embodiment has a similar configuration as well as similar functions and effects as those of the first embodiment.

The present disclosure has been described based on embodiments, however, it should not be construed that the present disclosure is limited to these embodiments and configurations. The present disclosure includes various modified examples and modifications in an equivalent range. Additionally, one category or spirit of the present disclosure includes various combinations or shapes and other combinations or shapes that include only one element, one or more elements, or one or more elements thereof.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 201628248 [0001]
• JP 5517686 B [0007]

Claims (4)

An ignition device (1) for ignition on a spark plug (13) connected to a secondary winding (12) of an ignition coil (10), the device comprising: an ignition switching element (2) connected to a primary winding (11) of the ignition coil connected is; a capacitor (3) connected to a control terminal (21) of the ignition switching element; a pre-drive switching element (5) connected in parallel with the capacitor; a pull-up resistor (19) connected to a point located between the control port and the capacitor and a power source (14); and an off-DC circuit (4 _OFF ) electrically connected to the control terminal and the capacitor and configured to discharge an electric charge stored at a DC current in the capacitor. An ignition device for ignition on a spark plug (13) connected to a secondary winding (12) of an ignition coil (10), the device comprising: an ignition switching element (2) connected to a primary winding (11) of the ignition coil; a capacitor (3) connected to a control terminal (21) of the ignition switching element; a pre-drive switching element (5) connected in parallel with the capacitor; and an on-DC circuit (4 _ON ) electrically connected to the control terminal and the capacitor and configured to charge the capacitor at a DC current. Ignition device according to Claim 2 , Further comprising an off-DC circuit, which is electrically connected to the control terminal and the capacitor and is configured to discharge an electric charge, which is stored at a direct current in the capacitor. Ignition device according to Claim 3 wherein the on-dc circuit and the off-dc circuit each comprise a switching transistor (40) for switching between conduction and interruption of a current, control terminals of the two switching transistors are connected to a common signal line (49), and the two switching transistors are complementary transistors configured such that one of the switching transistors is in an off state when the other is in an on state.

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