Ignition coil with controllable ignition voltage and ignition energy

Abstract

An ignition coil with controllable ignition voltage and ignition energy, comprising a DC power supply E, an ignition switch K and a first switch element connected to a primary coil L1 in sequence, a secondary coil L2 and a spark plug gap coupling, and an energy storage unit connected in parallel in the primary coil L1 loop, one end of the energy storage unit is connected to the ignition switch K, and the other end is connected to the first switch element. The ignition coil proposed by the present invention combines capacitor energy storage ignition and inductor energy storage ignition TCI, so that the ignition energies of capacitor energy storage ignition and inductor energy storage ignition TCI are superimposed, and ignition high voltage is generated by capacitor energy storage ignition, and ignition energy is generated by inductor energy storage, so that the ignition voltage and ignition energy are controllable respectively, thereby forming excellent ignition characteristics. And different ignition energies can be obtained by controlling the charging current of the primary coil to meet the requirements of the engine for ignition energy under different working conditions.

Description

Technical Field

[0001] The invention relates to the field of internal combustion engine ignition devices, in particular to an ignition coil with controllable ignition voltage and ignition energy. Background Art

[0002] The operation of the internal combustion engine requires the ignition coil to generate a high voltage to break through the gap between the spark plug electrodes to form a spark, ignite the combustible mixture in the cylinder to generate pressure so that the engine can work normally. There are two common working modes of the ignition coil, one is the inductive energy storage ignition mode, referred to as TCI, and the other is the capacitor energy storage ignition mode, referred to as CDI. The ignition high voltage rise rate generated by the inductive energy storage ignition TCI mode is limited and sensitive to high-voltage loads. When the insulation of the spark plug decreases or the spark plug carbon deposits and leaks, the ignition voltage drops quickly and causes misfires; its advantages are high efficiency in converting electrical energy into ignition energy, long duration of spark current, and large ignition energy. The capacitor energy storage ignition mode CDI has a fast voltage rise rate, is less sensitive to high-voltage loads, and is not prone to misfires. However, the generated ignition spark current has a short duration, small ignition energy, and low efficiency in converting electrical energy into ignition energy, which cannot meet the requirements of ignition energy under various engine working conditions.

[0003] Through searching, there are technical documents related to ignition devices in the prior art. For example, the invention patent publication document with the publication number "CN103821656A" and the name "A gas engine multi-mode discharge ignition system". It includes an ignition controller, a power supply, a capacitor energy storage ignition coil, a first anti-reverse breakdown diode, a high-voltage line interface, a second anti-reverse breakdown diode, an inductive energy storage ignition coil and a spark plug. The engine provides the top dead center signal and the speed signal to the ignition controller in real time. The top dead center signal and the speed signal are processed by the ignition controller to generate an ignition signal pulse. The signal pulse controls the discharge time of the capacitor energy storage ignition coil and the inductive energy storage ignition coil. In this comparative document, dual-coil discharge is adopted, and the capacitor energy storage ignition coil discharge, the inductive energy storage ignition coil discharge or the composite discharge can be selected according to the needs, but the circuit structure and control of the dual-coil discharge are relatively complicated.

[0004] For example, the invention patent publication document with the publication number of "CN118824711A" and the name of "Automobile Ignition Coil and Ignition Controller thereof". In the disclosed technical solution, an energy storage module is arranged on the main shell, and the energy storage module is electrically connected to the primary coil in parallel. When the primary coil is connected to a DC power supply, the energy storage module and the primary coil synchronously store electric field energy and magnetic field energy respectively. A reversal circuit is electrically connected between the energy storage module and the primary coil. When the reversal circuit responds to the DC power supply being disconnected from the primary coil, the energy storage module and the primary coil are connected to provide a reverse voltage transmitted to the primary coil in the reverse direction, and the magnitude of the reverse voltage is equal to the self-inductance voltage generated by the primary coil. The present invention uses energy storage components to achieve that when the coil is powered off, the self-inductance voltage generated by the inductor is offset by the reverse current voltage, thereby achieving the effect of quickly eliminating the magnetic field, achieving the instantaneous disappearance of the magnetic field of the primary coil, demagnetization of the iron core, and rapid contraction of the magnetic lines of force to cut the secondary coil to generate high voltage for ignition operation. It can be seen that the energy storage module in the comparative document functions to generate a reverse current voltage to offset the self-inductance voltage generated by the inductor, and cannot participate in ignition discharge.

[0005] The ignition voltage and ignition energy of TCI and CDI, two different energy storage ignition methods, are output synchronously. A large ignition energy means a high ignition voltage, and a small ignition energy means a low ignition voltage. However, the engine's ignition characteristic requirement is that the ignition voltage is high under various working conditions to ensure the breakdown of the spark plug electrode gap. The engine has different requirements for ignition energy under different working conditions. Therefore, it is of great significance to propose an ignition coil in this field with controllable ignition voltage and ignition energy. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides an ignition coil with controllable ignition voltage and ignition energy, comprising a DC power supply E, an ignition switch K and a first switching element connected to a primary coil L1 in sequence, a secondary coil L2 and a spark plug gap coupled, and an energy storage unit connected in parallel in the primary coil L1 loop, one end of the energy storage unit being connected to the ignition switch K, and the other end being connected to the first switching element.

[0007] Furthermore, the energy storage unit includes an energy storage capacitor C, the energy storage capacitor C is connected to the second switch element, one end of the energy storage capacitor C is connected to the primary coil L1, and one end of the second switch element is connected to the primary coil L1.

[0008] Furthermore, both ends of the energy storage capacitor C are connected to a boost and voltage stabilization unit.

[0009] Furthermore, a pulse transformer BK is connected between the first switching element and the second switching element.

[0010] Furthermore, the first switch element is connected to a monostable control unit and then connected to a pulse transformer BK.

[0011] Furthermore, the boost voltage stabilizing unit is grounded via a third switch element, and the output end of the monostable control unit is connected to the third switch element.

[0012] Furthermore, the second switch element is a thyristor SCR, the first switch element is a transistor BG1, the control electrode of the thyristor SCR is connected to the secondary coil of the pulse transformer BK, the anode is connected to the energy storage capacitor C, and the cathode is connected to the collector of the transistor BG1.

[0013] Furthermore, the third switch element is a transistor BG2, the boost voltage stabilizing unit is connected to the collector of the transistor BG2, the emitter of the transistor BG2 is grounded, and the output end of the monostable control unit is connected to the gate of the transistor BG2.

[0014] Furthermore, the secondary coil L2 is also connected to a reverse voltage stabilizing diode DW.

[0015] Furthermore, the output voltage of the boost stabilizing unit is between 350V and 450V.

[0016] Compared with the prior art, the technical solution of the present application has the following beneficial effects: the ignition coil proposed by the present invention combines capacitor energy storage ignition and inductor energy storage ignition TCI, so that the ignition energy of capacitor energy storage ignition and inductor energy storage ignition TCI is superimposed, and the ignition high voltage is generated by capacitor energy storage ignition, and the ignition energy is generated by inductor energy storage, so that the ignition voltage and ignition energy can be controlled separately, thereby forming an excellent ignition characteristic. And different ignition energies can be obtained by controlling the charging current of the primary coil to meet the ignition energy requirements of the engine under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : Schematic diagram of the circuit of the ignition coil.

[0018] Figure 2 : Ignition voltage timing diagram.

[0019] Figure 3 : Spark current timing diagram. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] like Figure 1An ignition coil with controllable ignition voltage and ignition energy comprises a DC power supply E, an ignition switch K and a first switch element connected to a primary coil L1 in sequence, a secondary coil L2 is gap-coupled with a spark plug, and an energy storage unit 1 is connected in parallel in the primary coil L1 loop, one end of the energy storage unit 1 is connected to the ignition switch K, and the other end is connected to the first switch element.

[0022] In this embodiment, the DC power supply E, the ignition switch K, the first switch element and the primary coil L1 constitute the basic circuit structure of the inductive energy storage ignition TCI in the prior art. The first switch element is connected to the engine ECU and is controlled by the ignition signal. When the ignition switch K is closed, the engine ECU continuously sends a high-level signal to the first switch element, and the primary coil L1 is charged and stored in the process. When the high-level signal sent by the engine ECU to the first switch element becomes a low level, the first switch element is turned off. At this time, the ignition energy of the primary coil L1 is coupled to the spark plug through the secondary coil L2. At this time, the current of the primary coil L1 disappears, the magnetic field of the core contracts suddenly, and the secondary coil L2 induction outputs a high voltage to break through the spark plug electrode gap to generate sparks and release energy. This inductive energy storage ignition TCI method generates a limited ignition high voltage rise rate and is sensitive to high-voltage loads. When the insulation of the spark plug decreases or carbon deposits leak electricity, the ignition voltage drops quickly, resulting in easy misfires. Its advantages are high efficiency in converting electrical energy into ignition energy, long duration of spark current, and large ignition energy. In this embodiment, the energy storage unit 1 is connected in parallel in the primary coil L1 loop. In the charging stage, the energy storage unit is charged and stored synchronously. In the ignition stage, the energy storage unit 1 discharges and supplies energy to the primary coil L1 synchronously. Due to the high turns ratio between the primary coil L1 and the secondary coil L2, the secondary coil L2 outputs a high voltage, which is significantly higher than the discharge voltage of the primary coil L1 and will generate a higher ignition voltage after coupling with the secondary coil L2. By combining the energy storage unit 1 and the inductive energy storage ignition TCI, the ignition energy of the energy storage unit 1 and the ignition energy of the inductive energy storage ignition TCI are superimposed, and the energy storage unit 1 is used to generate ignition high voltage, and the inductive energy storage is used to generate ignition energy, so that the ignition voltage and ignition energy can be controlled separately, thereby forming an ignition high voltage with excellent ignition performance. In addition, different ignition energies can be obtained by controlling the charging current of the primary coil L1 to meet the ignition energy requirements of the engine under different working conditions.

[0023] In a more preferred embodiment, the energy storage unit 1 includes an energy storage capacitor C, the energy storage capacitor C is connected to the second switch element, one end of the energy storage capacitor C is connected to the primary coil L1, and one end of the second switch element is connected to the primary coil L1. Figure 1In the charging stage, both the energy storage capacitor C and the primary coil L1 are charged and stored. When the ignition signal is generated, the first switch element is turned off and the second switch element is turned on. At this time, both the energy storage capacitor C and the primary coil L1 begin to supply energy. The energy storage capacitor C can form a higher and constant ignition voltage through the coupling of the primary coil L1 and the secondary coil L2. The voltage rise rate is fast, the sensitivity to high-voltage loads is low, and it is not easy to cause misfires. Since the energy supply time of the energy storage capacitor C is short, the primary coil L1 will continue to discharge and supply energy to provide ignition energy after its energy supply ends, thereby superimposing high-performance ignition energy.

[0024] In a more preferred embodiment, the energy storage capacitor C is further connected to a boost voltage stabilizing unit 2. The boost voltage stabilizing unit 2 is a DC / DC boost voltage stabilizing circuit in this embodiment, which converts the DC low voltage of the DC power source E into DC high voltage to charge the energy storage capacitor C for energy storage.

[0025] In a more preferred embodiment, a pulse transformer BK is further connected between the first switch element and the second switch element. When the first switch element is turned off due to the generation of an ignition signal, its reverse peak voltage satisfies the turn-on trigger voltage of the second switch element after coupling through the pulse transformer BK, so that the second switch element can be turned on while the first switch element is turned off, so that the energy storage capacitor C and the primary coil L1 can be discharged and energized synchronously.

[0026] In a more preferred embodiment, the first switch element is connected to the monostable control unit 3 and then connected to the pulse transformer BK. After the first switch element is turned off by the ignition control signal, the anti-peak pulse generated by the first switch element passes through the monostable control unit 3 and outputs a stable and controllable peak pulse, thereby further ensuring that the second switch element can be turned on after the first switch element is turned off.

[0027] In a more preferred embodiment, the boost voltage stabilizing unit 2 is grounded through a third switch element, and the output end of the monostable control unit 3 is connected to the third switch element. The boost voltage stabilizing unit 2 will continue to work when charging the energy storage capacitor C. When the second switch element is turned on, the energy storage capacitor C discharges and supplies energy. When the energy storage capacitor C is discharged, the second switch element needs to be turned off. At this time, the boost voltage stabilizing unit 2 should be prevented from continuing to work in this process. Therefore, when the monostable control unit 3 outputs the second switch element to turn on, it also turns off the third switch element and cuts off the charging circuit for the energy storage capacitor C. When the energy storage capacitor C is discharged, the second switch element can be reliably turned off and the next charging energy storage cycle can be entered.

[0028] like Figure 1As shown. The second switch element is a thyristor SCR, and the first switch element is a transistor BG1. The control electrode of the thyristor SCR is connected to the secondary coil of the pulse transformer BK, the anode is connected to the energy storage capacitor C, and the cathode is connected to the collector of the transistor BG1. The third switch element is a transistor BG2, the boost stabilizing unit 2 is connected to the collector of the transistor BG2, the emitter of the transistor BG2 is grounded, and the output end of the monostable control unit 3 is connected to the gate of the transistor BG2. During the ignition process, Figure 2 and Figure 3 The timing waveforms of the ignition voltage and spark current are shown.

[0029] When the ignition switch K is closed, the DC / DC boost voltage regulator circuit works, converting the low-voltage DC power supply E into high-voltage DC to charge the energy storage capacitor C. The process can be seen in Figure 2 The voltage of capacitor Cv in the ignition source is 0.08V. At this time, the thyristor SCR is in the cut-off state, and the energy storage capacitor C is quickly filled. The electric energy is stored in the energy storage capacitor C and waits for the thyristor SCR to be turned on to discharge the primary coil L1. When the ignition switch K is closed, the positive pole of the DC power supply is connected through the primary coil L1 and the collector of the transistor BG1. When the transistor BG1 receives the ignition signal, Figure 2 When the ignition signal Vb is at a high level, the gate of transistor BG1 is turned on at a high level. The primary coil L1 then rises according to the inductance charging curve, see Figure 2 The charging current Id in the primary coil L1 is charged and stored in the process. When the ignition signal becomes low level, the transistor BG1 is turned off. The current in the primary coil L1 is interrupted, the magnetic field of the iron core contracts suddenly, and the primary coil L1 and the secondary coil L2 respectively induce a sharp wave pulse. Figure 2 The VD and TCI transformer waveforms are shown in Figure 1. The spike pulse of the primary coil L1 triggers the monostable control unit 3 circuit to work, outputs a spike pulse, and triggers the thyristor SCR to turn on through the pulse transformer BK coupling. The energy storage capacitor C discharges the primary coil L1 through the thyristor SCR. The secondary coil L2 generates high voltage, see Figure 2 Medium CDI output voltage.

[0030] Since the conduction time of the thyristor SCR after triggering is extremely short, the TCI discharge and CDI discharge are carried out simultaneously, and the output high voltage waveform is a superposition of two modes, see Figure 2 The synthesized output high voltage waveform in .

[0031] To ensure that the thyristor SCR can be turned off automatically when the energy on the energy storage capacitor C is fully discharged and the current is zero after the thyristor SCR is triggered and turned on, the DC / DC boost voltage stabilization circuit must stop working at this time. When the monostable control unit 3 detects the reverse peak generated when the transistor BG1 is turned off, it will output a square wave pulse of a certain width to control the transistor BG2. The width time of the square wave pulse will be greater than the discharge time of the energy storage capacitor C, so that the thyristor SCR can be reliably turned off. For details, please refer to Figure 2 DC / DC working timing.

[0032] In a more preferred embodiment, the secondary coil L2 is further connected to a reverse voltage stabilizing diode DW to prevent the ignition voltage from being too high and damaging the device.

[0033] In a more preferred embodiment, the output voltage of the boost stabilizing unit 2 is between 350V and 450V.

[0034] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ignition coil with controllable ignition voltage and ignition energy, comprising a DC power supply E, an ignition switch K and a first switch element connected to a primary coil L1 in sequence, a secondary coil L2 and a spark plug electrode gap coupled, characterized in that: An energy storage unit (1) is also connected in parallel in the primary coil L1, wherein one end of the energy storage unit (1) is connected to the ignition switch K, and the other end is connected to the first switch element.

2. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 1, characterized in that: The energy storage unit (1) comprises an energy storage capacitor C, the energy storage capacitor C is connected to the second switch element, one end of the energy storage capacitor C is connected to the primary coil L1, and one end of the second switch element is connected to the primary coil L1.

3. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 2, characterized in that: Both ends of the energy storage capacitor C are also connected to a boost and voltage stabilization unit (2).

4. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 3, characterized in that: A pulse transformer BK is further connected between the first switching element and the second switching element.

5. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 4, characterized in that: The first switch element is connected to the monostable control unit (3) and then connected to the pulse transformer BK.

6. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 5, characterized in that: The boost stabilizing unit (2) is grounded via a third switch element, and the output end of the monostable control unit (3) is connected to the third switch element.

7. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 6, characterized in that: The second switch element is a thyristor SCR, and the first switch element is a transistor BG1. The control electrode of the thyristor SCR is connected to the secondary coil of the pulse transformer BK, the anode is connected to the energy storage capacitor C, and the cathode is connected to the collector of the transistor BG1.

8. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 7, characterized in that: The third switch element is a transistor BG2, the boost stabilizing unit (2) is connected to the collector of the transistor BG2, the emitter of the transistor BG2 is grounded, and the output end of the monostable control unit (3) is connected to the gate of the transistor BG2.

9. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 8, characterized in that: The secondary coil L2 is also connected to a reverse voltage stabilizing diode DW.

10. The ignition coil with controllable ignition voltage and ignition energy as claimed in claim 9, characterized in that: The output voltage of the boost and voltage stabilization unit (2) is between 350V and 450V.

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