[0042] The technical solutions of the present invention will be described in conjunction with the accompanying drawings, and the described embodiments are merely embodiments of the invention, not all of the embodiments. Based on the embodiments of the invention, all other embodiments obtained by those of ordinary skill in the art without performing creative labor premises.
[0043] like Figures 2 to 5 As shown, a VVA solenoid valve drive system having a closed detection function is provided, including:
[0044] VVA solenoid valve L, one end is connected to the power supply + BP by high-end transistor Q1, and the other end is sequentially grounded by low-end transistors Q2 and sampling resistor R1, and the high-end transistor Q1 and the common end of the VVA solenoid valve L connect the first diode tube. The cathode of D1, the anode of the first diode D1, the VVA solenoid valve L, the second diode D2, the second diode D2, and the second diode D2. Cathode connection of the power supply + BP;
[0045] The drive module is connected to the high-end driving circuit and drives the high-end transistor Q1 by a high-end driving circuit, and the low-end transistor Q2 is driven by a low-end driving circuit;
[0046] The current sampling amplifying circuit, the input terminal is connected to the low-end transistor Q2 and the sampling resistor R1, the output terminal is connected to the input end of the drive module, the input of the detection circuit;
[0047] The closed detection circuit is connected to the drive module; the closed detection circuit works with the drive module to detect if the VVA solenoid valve is completely closed;
[0048] Therefore, the driving module and the closed detection circuit can be sampled to the electromagnetic valve working current I flow through the VVA solenoid valve L in real time by current sampling amplifying circuit, respectively. High-end drive circuits, low-end drive circuits, and current sampling amplifying circuits can specifically be implemented by conventional circuit configurations, which are not described in detail for their specific structures.
[0049] In the present invention, the driving module drives the working process of the VVA solenoid valve L by driving the high-end transistor Q1 and the low-end transistor Q2, the same, the VVA solenoid valve L is returned to the normally open state from the normally open state. The drive process mainly includes excitation phase, rapid improvement phase, maintenance stage, and open phase, such as image 3 The current waveform of the working current shown and Figure 4 The corresponding schematic of the current waveform shown and each stage is described in the following periods as follows:
[0050] 1) Excitation phase: The drive module outputs a valid high-end driving signal to the high-end driving circuit, driving the high-end transistor Q1 closure, the driving module outputs a valid low-end driving signal to the low-end driving circuit, driving the low-end transistor Q2 closed, at this time Power supply + BP, high-end transistors Q1, VVA solenoid valve L, bottom end transistor Q2 and sampling resistor R1 and ground end forming circuit, flowing through the VVA solenoid valve L operation increases and stabilizes in magnetization current Ibias Place.
[0051] As a further improvement of the present invention, the electromagnetic valve operating current I is not constant to stabilize at the magnetization current IBIAS, but is stabilized in the form of a sawtooth wave in the magnetization current IBIAS, i.e., in the form of a rectangular wave, in the excitation lower limit threshold IBIAS_DOWN, and excitation The threshold IBIAS_UP fluctuates, the excitation lower threshold IBIAS_DOWN is smaller than the magnetization current IBIAS, the magnetization current IBIAS is smaller than the excitation upper threshold IBIAS_UP. When the drive module outputs a valid high-end drive signal and a valid low-end driving signal until the solenoid operating current I gradually increases to the excitation upper threshold IBIAS_UP, continue to output a valid low-end driving signal, switch to the output invalid. High-end drive signal, at this time, the high-end transistor Q1 is closed, the low-end transistor Q2 is closed, the VVA solenoid valve L, the low-end transistor Q2 and the sampling resistor R1 and the first diode D1 form the continuous flow circuit, and the working current I of the solenoid valve gradually decreases. When the drive module detects that the electromagnetic valve operating current I falls to the excitation lower limit threshold IBIAS_DOWN, continue to output a valid low-end drive signal, re-output the effective high-end driving signal, the high-end transistor Q1 is again closed, the electromagnetic valve operating current I resumes rise Until the excitation upper threshold IBIAS_UP; repeated the above process, the solenoid valve operating current I is stabilized at the magnetization current Ibias.
[0052] 2) Rapid improvement phase: After the excitation phase is completed, it is specifically that after the excitation phase of the VVA solenoid valve L, the drive module outputs a continuous and effective low-end driving signal to the low-end driving circuit, drive The low-end transistor Q2 is closed, and the sustained effective high-end driving signal is output to the high-end driving circuit, driving the high-end transistor Q1 closed. As described above, at this time, the power supply + BP, the high-end transistors Q1, the VVA solenoid valve L, the bottom transistor Q2, and the sampling resistor R1 and the ground end form a circuit, and the working current I flowing through the VVA solenoid valve L continues to rise until peak Current IPEAK.
[0053] When the drive module samples from the current sampling amplifying circuit to the solenoid valve working current 1 of the VVA solenoid valve L, the driving module outputs the high-end drive signal in the PWM wave form to the high-end drive signal from the magnetization current IBIAS The PWM wave of the high-end drive signal has a predetermined duty cycle and frequency, and the invalid level is greater than the effective level. The high-end driving circuit drives the high-end transistor Q1 to be off during the invalid level of the PWM wave, so that the electromagnetic valve operating current I decreases, and the high-end driving circuit drives the high-end transistor Q1 to close, so that the solenoid valve The working current I rises, so that the rapid lift phase of the VVA solenoid valve L is ended.
[0054] During the high-end driving signal of the drive module output PWM wave, due to the long time when the PWM wave of the high-end driving signal is longer, the electromagnetic valve operating current I decrease is greater than the rising magnitude, so the electromagnetic valve working current I is graded. Descended sawtooth form. Until the VVA solenoid valve L completely closed the electromagnetic valve operating current I reached the minimum, at which point the VVA solenoid valve L characteristics change, although the PWM waveform of the high-end drive signal is consistent, but the current rising rate during the effective level is more than the invalid level. Fast falling rate, so that the solenoid valve operating current I turned again to rose stepwise, until the end of the rapid increase phase. Therefore, in the present application, the solenoid valve operating current I is a "V"-type change structure that is raised in the overall decline in the rapid lift stage.
[0055] 3) Maintenance stage: After the end of the rapid increase, the VVA solenoid valve L has been completely closed through the rapid increase stage, so it is necessary to enter a small sustain current to produce a sufficiently large electromagnetic force to ensure VVA electromagnetic Reliable close up of the valve L, and small sustain current can reduce energy consumption, reduce the electromagnetic coil of the VVA solenoid valve L, and facilitate the rapid opening of the VVA solenoid valve L.
[0056] Therefore, after entering the maintenance phase, the drive module continues to output the continuous and effective low-end driving signal to keep the low-end transistor Q2 remain closed, and outputs a continuously invalid high-end driving signal to the high-end driving circuit, driving the high-end transistor Q1 to disconnect, so that electromagnetic The valve operating current I decreases and remains at the maintenance current hold.
[0057] Similarly, as a further improvement of the present invention, the electromagnetic valve operating current I is not constant to stabilize at the sustain current IHOLD, but is stabilized in the form of a sawtooth wave in the maintenance current IHOLD, i.e., in the form of a rectangular wave, a lower limit threshold IHOLD_DOWN And maintaining the upper threshold IHOLD_UP fluctuations, maintaining the lower threshold IHOLD_DOWN is smaller than the maintenance current hold, maintaining the current IHOLD is smaller than the maintenance upper threshold IHOLD_UP. Then the drive module outputs a valid low-end drive signal and the invalid high-end driving signal so that the solenoid valve operating current I gradually decreases from the peak current IPEAK. When the drop arrives at the sustain limit threshold IHOLD_DOWN, continue to output a valid low-end drive signal, change to the output effective high-end drive signal such that the solenoid valve is operated by the current I rise. When rising reaches the sustain threshold IHOLD_UP, it is again changed to the output invalid high-end driving signal, repeating the above process, so that the solenoid valve operating current I is stable at the maintenance current IHOLD.
[0058] 4) Opening stage: After the end of the VVA solenoid valve, the driving process of the VVA solenoid valve ends and enters the open phase, at which time the drive module outputs the continuously invalid low-end driving signal to the low-end driving circuit, drive low-end transistors Q2 is disconnected, the drive module outputs the high-end driving signal to the high-end driving circuit, drive high-end transistor Q1 to open, VVA solenoid valve L, first diode D1, power supply + BP, second diode D2, and ground The end forms a continuation circuit, and the electromagnetic valve operating current I gradually decreases until 0, the entire driving process ends, and the VVA solenoid valve L is re-opened.
[0059]At the same time, during the above driving process, at least in the rapid increase stage, the closed detection circuit is also sampled to the solenoid valve operating current I, and the solenoid valve operating current I during the high-end driving signal of the drive module output PWM wave. In the case where the stepwise decreased step-by-step, when the closed detection circuit is detected to detect the solenoid operating current I below less than the predetermined threshold U0, the output first level is switched to the output second level; the solenoid valve work The current I falls until the VVA solenoid valve reaches the minimum value and begins to rise step-by-step rising sawtooth wave form, the closing detecting circuit is detected to rise to the solenoid operating current I to reach the predetermined threshold U0. Switching from the output second level to the output first level. Among them, one of the first level and the second level is a high level, one is low, so the output of the closed detecting circuit is at the lowest of the working current I of the solenoid valve, that is, the VVA solenoid valve L is completely closed. A pulse signal is output, so the level of the closed detection circuit is used to indicate the closed state of the VVA solenoid valve L, and the closing state of the VVA solenoid valve L can be determined by monitoring the output of the closed detection circuit. The output of the actual closing detection circuit can be directly drawn to the outside or connected to the drive module. Figure 4 The first level is low, and the second level is high as an example.
[0060] like figure 2 As shown, as further defined by the present invention, the closure detecting circuit may include a comparator U1, and the output of the comparator U1 serves as an output terminal of the closed detecting circuit, a reverse phase input end of the comparator U1. The output of the current samples amplify the output of the circuit to acquire the electromagnetic valve operating current I, the first level is low, the second level is high; the same phase input of the comparator U1 is connected by the third resistor R3 to connect the threshold voltage + V The in-phase input of the comparator U1 is also grounded by the second resistance R2 and the third transistor Q3, the third transistor Q3 being controlled to the drive module. The closing detection circuit sampling the solenoid valve operating current I during the entire driving process, while the driving module drives the third transistor Q3 closed during the rapid lift stage of the VVA solenoid valve, driving the third transistor Q3 at the remaining stage. disconnect. Therefore, in the excitation phase, the main stage and the open phase, the drive module controls the third transistor Q3 to be disconnected. At this time, the voltage of the same phase input terminal of the comparator U1 is the threshold voltage V, the threshold voltage V is greater than the maximum of the current sampling amplification circuit. The output value, so the comparator U1 constant output is high in the excitation phase, the maintenance phase and the open phase. In the rapid increase stage, the drive module controls the third transistor Q3 closing. At this time, the voltage of the same phase input end of the comparator U1 becomes a predetermined threshold U0 = R2 * V / (R2 + R3), compared to the threshold voltage V decreases. The specific voltage of the predetermined threshold U0 = R2 * V / (R2 + R3) can be customized, but smaller than the value of the peak current IPEAK and greater than the minimum value of the working current I in the fast lifting phase, therefore rapidly In the stage, the electromagnetic valve operating current I rises from the magnetization current, and in this process, I Figure 4 The waveform schematic shown can be seen that the output of the comparator U1 has a high level pulse signal when the VVA solenoid valve L is closed, so that the closing state of the VVA solenoid valve L can be detected by detecting the high level pulse.
[0061] In the present invention, the above-described control function of the drive module is completed by a plurality of circuit structures, and the drive module can include an MCU, a logic processing unit, a peak current comparison circuit, and a peak state latch circuit. The peak current comparison circuit can be based on the existing The comparator chip implementation, the peak state latch circuit can be implemented based on the existing latch chip. like figure 2 Design, the MCU is connected to the low-end driving circuit, and outputs the low-end driving signal A to control the on state of the low-end transistor Q2 to the low-end driving circuit; the MCU also connects the logic processing unit, and outputs excitation enable to the logic processing unit. Signal B, fast lift enable signal C, maintain enable signal D and PWM signal E, PWM signal E has a predetermined duty cycle and frequency. At the same time, the MCU captures the output of the closed detection circuit to detect the closed state of the VVA solenoid valve. The peak current comparison circuit is used to set the peak current size and compare the input of the peak current comparison circuit connect the current sample amplifying circuit, and the output is connected to the peak state latch circuit; the peak state latch circuit The output is connected to the logic processing unit. The logic processing unit is configured to implement the control signal generated by the MCU and the logical operation of the respective hardware control circuit output signals, connected to the high-end driving circuit, and control the high-end transistor Q1 through the high-end driving circuit. The logic processing unit is connected and controlled in the state of the third transistor Q3 in the closed detection circuit, and if the output of the closed detection circuit is introduced to the drive module, the output of the closed detecting circuit is connected to the MCU. In addition, the drive module further includes a sustain current closure circuit for closed loop modulation sustain current, and maintains the output of the input of the current closure ring modulation circuit to the output of the current sample amplifying circuit, and maintain the output of the current closure ring modulation circuit. Connect the logic processing unit. In addition, the drive module further includes an excitation current closure circuit for closed-loop modulation excitation current, an input of an input of the excitation current closure ring modulation circuit, an output of an output terminal of the excitation current closure ring modulation circuit, and a logic processing unit. The maintenance current turning ring modulation circuit and the excitation current closure ring modulation circuit are all transmitted to the logic processing unit, and can be constructed based on the existing comparator chip, respectively. like Figure 5 As shown, the mating process of the above-mentioned various circuits in the drive module is as follows, and the present invention is effective and the low level is invalid as an example:
[0062] Regardless of the VVA solenoid valve L, the MCU continuously outputs a PWM signal E having a predetermined duty ratio and frequency to the logic processing unit.
[0063] 1) When the VVA solenoid valve L starts the action, first enter the excitation phase, the MCU outputs a valid low-end driving signal A, and outputs a valid excitation enable signal B, and the excitation current closure ring modulation circuit will be obtained from the current sample amplification circuit. The electromagnetic valve operating current I compares and outputs the corresponding signal, and the logic processing unit outputs the corresponding high-end driving signal from the high-end driving circuit based on the output of the excitation enable signal B and the output of the excitation current, so that the solenoid valve is operated. I rise from 0 and stabilizes in magnetization current IBIAS. Specific: Excitation current closure ring modulation circuit outputs an effective level, the logic processing unit is operated in accordance with the effective level output of the active excitation enable signal B and the excitation current turnt modulation circuit output, driving the high-end transistor Q1 closed, The working current I of the solenoid valve rises. Excitation current turning ring modulation circuit When detecting that the electromagnetic valve operating current I reaches the excitation upper threshold IBIAS_UP, the logic processing unit is continuously invalidated according to the effective excitation enable signal B, and the invalid level output output of the excitation current turnt modulation circuit. High-end drive signal f, drive high-end transistor Q1 is broken, the electromagnetic valve operating current I decreases; the excitation current turning ring modulation circuit re-outputs the effective level when the electromagnetic valve operating current I falls to the excitation lower threshold IBIAS_DOWN, and the logic processing unit is again output. Effective high-end drive signal f, solenoid valve operating current I rises again; repeated process until the extension process ends, the MCU stops output effective excitation enable signal B.
[0064] 2) When entering the rapid promotion phase, the MCU continues to output a valid low-end driving signal A, and outputs a valid fast lifting enable signal C, and the peak current comparison circuit will work currently from the current sample amplified circuit I and peak value. Current IPEAK is compared, when I
[0065] 3) When entering the maintenance phase, the MCU continues to output a valid low-end driving signal A, and output a valid maintenance enable signal D, and maintain the current closure ring modulation circuit will work current I and maintain the electromagnetic valve obtained from the current sample amplified circuit. Current IHOLD performs comparison and outputs the corresponding signal, and the logic processing unit outputs the corresponding high-end driving signal f according to the output of the maintenance signal D and the output of the current turning ring modulation circuit, so that the electromagnetic valve operating current I decreases and stabilizes Current IHOLD. Specific: Maintaining the current turning ring modulation circuit output invalid level, the logic processing unit is operated in accordance with the effective level output of the invalid level output of the maintenance current turnt modulation circuit, driving the high-end transistor Q1 to open The working current I of the solenoid valve decreases. The maintenance current turning ring modulation circuit outputs an active level when the solenoid valve operating current I reaches the lower limit threshold IHOLD_DOWN, and the logic processing unit is continuously effective based on the effective level output of the effective maintenance enable signal D and the maintenance current closure modulation circuit. High-end drive signal f, drive high-end transistor Q1 closed, and the working current I of the solenoid valve rises. The maintenance current turning ring modulation circuit re-outputs an invalid level when the solenoid valve working current I reaches the upper threshold, and the logic processing unit is continuously invalidable according to the effective level output of the effective maintenance enable signal D and the maintenance current closure modulation circuit. The high-end drive signal f, the high-end transistor Q1 is driven, and the working current I of the solenoid valve is lowered. The above process is repeated until the end of the maintenance phase, the MCU stops the output effective sustain enable signal D.
[0066] 4) When entering the opening stage, the MCU output is invalid, low-end driving signal A causes the low-end transistor Q2, and the high-end transistor Q1 is also closed, and the working current I of the solenoid valve gradually decreases until 0.
[0067] In summary, the present invention utilizes the characteristics of the VVA solenoid valve itself, and when driving the VVA solenoid valve, the electromagnetic valve operating current is decreased step-by-step, and the servo is gradually rising step by step. The current change, so that the closing state of the VVA solenoid valve can be detected by the closed detection circuit, there is no need to increase the additional sensor, so that the VVA solenoid valve is not only an actuator or a sensor, and the solenoid valve can be detected to adjust the solenoid valve. The driving timing, improving the idle stability of internal combustion engines, increasing the torque of low speed working conditions, ensuring the power of the high-speed working condition, and improving the fuel economy of low-speed small loads has certain help.
[0068] It will be apparent to those skilled in the art, and In addition, it should be understood that although this specification describes the embodiments, it is not a separate technical solution, and this narrative method of the specification is simply, and those skilled in the art will use the specification as a whole. The technical solutions in each of the examples may also be appropriately combined to form other embodiments which will be appreciated by those skilled in the art.
