JP2020132118A - Negative actuator system - Google Patents

Abstract

To solve a problem that, when adjusting an opening of a negative pressure adjusting valve for adjusting the negative pressure of a negative pressure actuator without taking into consideration whether or not a brake booster uses the negative pressure of a vacuum pump, the negative pressure supplied to the negative pressure actuator may be insufficient.SOLUTION: A brake booster which operates with negative pressure generated by a vacuum pump as a power source is connected to the vacuum pump which generates the negative pressure. Also, a negative pressure actuator different from the vacuum pump is connected to the vacuum pump. A negative pressure adjusting valve is connected to an upper part of a negative pressure supply path for connecting the vacuum pump and the negative pressure actuator. When the brake booster uses the negative pressure of the vacuum pump, a valve control part for controlling the negative pressure adjusting valve largely controls an opening of the negative pressure adjusting valve compared with the case that the brake booster does not use the negative pressure.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle negative pressure actuator system.

The negative pressure actuator system of Patent Document 1 includes a vacuum pump for generating negative pressure. The vacuum pump operates by using the rotational torque of the crankshaft of the internal combustion engine as a drive source. A brake booster is connected to the vacuum pump via a negative pressure supply path. The brake booster uses the negative pressure supplied from the vacuum pump to increase the depressing force of the brake pedal. Further, a negative pressure actuator for driving a wastegate valve is connected to the vacuum pump via a negative pressure supply path. A negative pressure adjusting valve is mounted on the negative pressure supply path connecting the vacuum pump and the negative pressure actuator. By controlling the negative pressure actuator through the adjustment of the opening degree of the negative pressure adjusting valve, the opening degree of the wastegate valve is adjusted.

Japanese Unexamined Patent Publication No. 2013-227901

When the brake booster and the negative pressure actuator are connected to the same vacuum pump as in the negative pressure actuator system of Patent Document 1, the vacuum pump depends on whether or not the brake booster uses the negative pressure of the vacuum pump. There is a difference in the negative pressure that can be supplied. If the required negative pressure of the negative pressure actuator is calculated and the opening degree of the negative pressure adjustment valve is adjusted according to the required negative pressure without considering this point, the negative pressure supplied to the negative pressure actuator will be insufficient. There is.

Not limited to the example of the negative pressure actuator system of Patent Document 1, the same problem arises when a plurality of negative pressure actuators operating with negative pressure as a power source are connected to the same vacuum pump. ..

In order to solve the above problems, the present invention comprises a negative pressure supply source that generates a negative pressure, a first negative pressure actuator that operates using the negative pressure generated by the negative pressure supply source as a power source, and the negative pressure supply source. A second negative pressure actuator different from the first negative pressure actuator that operates using the negative pressure generated by the above is provided on a negative pressure supply path connecting the negative pressure supply source and the second negative pressure actuator. A negative pressure actuator system including a negative pressure adjusting valve and a valve control unit that controls the opening degree of the negative pressure adjusting valve according to the required negative pressure of the second negative pressure actuator. When the first negative pressure actuator uses the negative pressure of the negative pressure supply source, the negative pressure adjustment is performed as compared with the case where the first negative pressure actuator does not use the negative pressure. Greatly control the valve opening.

In the above configuration, when the negative pressure is supplied from the negative pressure supply source to the first negative pressure actuator, the negative pressure of the negative pressure supply source becomes weaker than in the case where the negative pressure is not supplied. According to the above configuration, the opening degree of the negative pressure adjusting valve becomes large under such a situation. As a result, the negative pressure is easily supplied from the negative pressure supply source to the second negative pressure actuator, and the negative pressure is less likely to be insufficient in the second negative pressure actuator.

Schematic diagram of an internal combustion engine and a negative pressure actuator system. Flowchart of wastegate valve control process.

An embodiment of the present invention will be described with reference to the drawings. First, a schematic configuration of the internal combustion engine 10 will be described.
As shown in FIG. 1, the internal combustion engine 10 includes an intake passage 11 for supplying intake air to the internal combustion engine 10. The downstream end of the intake passage 11 is connected to a cylinder 12 for mixing and burning fuel with the intake air. An exhaust passage 13 for exhausting the exhaust gas from the cylinder 12 to the outside extends from the cylinder 12.

A piston 15 is arranged in the cylinder 12 of the internal combustion engine 10. The piston 15 can reciprocate in the cylinder 12 in the axial direction of the cylinder 12. The piston 15 is connected to the crankshaft 17 via a connecting rod 16. A crank angle sensor 18 for detecting the crank angle CA of the crankshaft 17 is arranged in the vicinity of the crankshaft 17.

The crankshaft 17 is drive-connected to the drive wheels W via a transmission or differential gear (not shown). A brake disc rotor 19 that rotates integrally with the drive wheels W is fixed to the rotation shaft of the drive wheels W. When the fuel burns in the cylinder 12, the reciprocating motion of the piston 15 is converted into a rotary motion by the crankshaft 17 and transmitted to the drive wheels W.

A turbocharger 20 is attached to the intake passage 11 and the exhaust passage 13 so as to straddle both of these passages. Specifically, the turbine portion 21 of the turbocharger 20 is attached to the exhaust passage 13. On the other hand, the compressor portion 25 of the turbocharger 20 is attached to the intake passage 11. The turbine section 21 and the compressor section 25 are connected by a bearing section 23.

A turbine wheel 22 that rotates by the flow of exhaust gas is housed inside the turbine unit 21. One end of the connecting shaft 24 is connected to the turbine wheel 22. Most of the connecting shaft 24 is housed inside the bearing portion 23. Further, the connecting shaft 24 is rotatably supported by the bearing portion 23. The other end of the connecting shaft 24 reaches the inside of the compressor portion 25. The other end of the connecting shaft 24 is connected to the compressor wheel 26 inside the compressor section 25. When the turbine wheel 22 rotates due to the flow of exhaust gas, the compressor wheel 26 rotates accordingly. Then, when the compressor wheel 26 rotates, the intake air on the upstream side of the intake passage 11 is pumped to the downstream side.

The turbine section 21 is partitioned by a wastegate 27 that communicates the upstream side and the downstream side of the turbine section 21 with respect to the turbine wheel 22. Further, a wastegate valve 28 for opening and closing the wastegate 27 is attached to the turbine unit 21. By opening and closing the wastegate valve 28, the amount of exhaust gas flowing through the wastegate 27 is adjusted.

An air flow meter 31 that detects the flow rate Ga of the intake air flowing through the intake passage 11 is attached to the intake passage 11 of the internal combustion engine 10. The air flow meter 31 is located upstream of the compressor section 25 of the turbocharger 20 in the intake passage 11.

An intercooler 32 is attached to the downstream side of the compressor portion 25 in the intake passage 11. The intercooler 32 is pumped by the compressor section 25 of the turbocharger 20 to cool the hot intake air. A throttle valve 33 for adjusting the amount of intake air supplied to the cylinder 12 is attached to the downstream side of the intake passage 11 with respect to the intercooler 32. The throttle valve 33 adjusts the amount of intake air by adjusting the cross-sectional area of the flow path of the intake passage 11.

On the downstream side of the intercooler 32 in the intake passage 11 and on the upstream side of the throttle valve 33, a supercharging pressure sensor 34 that detects the pressure of the intake air pumped by the compressor unit 25 as the actual supercharging pressure Pa is located. It is installed. Further, a fuel injection valve 35 for supplying fuel into the cylinder 12 is attached to the downstream side of the throttle valve 33 in the intake passage 11.

Next, a schematic configuration of the negative pressure actuator system 40 will be described.
The negative pressure actuator system 40 includes a vacuum pump 41 as a negative pressure supply source for generating negative pressure. The vacuum pump 41 is drive-connected to the crankshaft 17 of the internal combustion engine 10 and operates by using the rotation of the crankshaft 17 as a power source.

One end of the first negative pressure supply path 42 is connected to the vacuum pump 41. The other end of the first negative pressure supply path 42 is connected to the brake booster 43. The brake booster 43 amplifies the depression force of the brake pedal 44 of the vehicle by utilizing the negative pressure supplied from the vacuum pump 41 and transmits it to the master cylinder 45. The master cylinder 45 converts the stepping force of the brake pedal 44 into hydraulic pressure. The brake booster 43 has a built-in pressure sensor 43a that detects the pressure Pn in the negative pressure chamber inside the brake booster 43. In this embodiment, the brake booster 43 corresponds to the first negative pressure actuator.

A brake mechanism 47 is connected to the master cylinder 45 via a hydraulic circuit 46. The brake mechanism 47 is arranged in the vicinity of the brake disc rotor 19 of the drive wheel W. The brake mechanism 47 is a so-called friction brake. When the brake pedal 44 is depressed and the hydraulic pressure supplied to the brake mechanism 47 rises, the brake pads of the brake mechanism 47 are slidably contacted with the brake disc rotor 19, and the rotation of the drive wheels W is decelerated.

One end of the second negative pressure supply path 51 is connected to the vacuum pump 41. A negative pressure actuator 52 is connected to the other end of the second negative pressure supply path 51. The negative pressure actuator 52 is a so-called diaphragm type actuator, and the output rod of the negative pressure actuator 52 is displaced by bending the diaphragm according to the strength of the negative pressure supplied to the negative pressure actuator 52.

A wastegate valve 28 is connected to the output rod of the negative pressure actuator 52 via a link mechanism 53. In this embodiment, when the negative pressure is not supplied to the negative pressure actuator 52, the opening degree of the wastegate valve 28 is fully opened. The larger the negative pressure supplied to the negative pressure actuator 52, the smaller the opening degree of the wastegate valve 28. In this embodiment, the negative pressure actuator 52 for opening and closing the wastegate valve 28 corresponds to the second negative pressure actuator.

A negative pressure adjusting valve 54 is attached in the middle of the second negative pressure supply path 51 that connects the vacuum pump 41 and the negative pressure actuator 52. The negative pressure adjusting valve 54 adjusts the negative pressure supplied to the negative pressure actuator 52 by adjusting the cross section of the flow path of the second negative pressure supply path 51. The negative pressure adjusting valve 54 is an electromagnetic valve, and the opening degree is adjusted according to the control duty ratio D of the current applied to the negative pressure adjusting valve 54. In this embodiment, the negative pressure adjusting valve 54 is a normally closed valve, which is fully closed when the control duty ratio is "0%" and fully opened when the control duty ratio is "100%".

The internal combustion engine 10 and the negative pressure actuator system 40 described above are controlled by the electronic control device 60.
Signals are input to the electronic control unit 60 from sensors at various locations. Specifically, a signal indicating the crank angle CA of the crankshaft 17 is input from the crank angle sensor 18 to the electronic control device 60. The electronic control unit 60 calculates the rotation speed of the crankshaft 17 per unit time as the engine rotation speed Ne based on the crank angle CA.

A signal indicating the pressure Pn in the negative pressure chamber is input to the electronic control unit 60 from the pressure sensor 43a of the brake booster 43. The electronic control unit 60 determines whether or not the brake booster 43 uses the negative pressure of the vacuum pump 41 based on the pressure Pn of the negative pressure chamber.

A signal indicating the intake flow rate Ga is input from the air flow meter 31 to the electronic control device 60, and a signal indicating the actual supercharging pressure Pa is input from the supercharging pressure sensor 34. Further, a signal indicating the vehicle speed SP of the vehicle is input from the vehicle speed sensor 61 to the electronic control device 60. Further, a signal indicating the depression amount Ac of the accelerator pedal is input from the accelerator stroke sensor 62 to the electronic control device 60. The electronic control unit 60 calculates the target boost pressure Pt of the turbocharger 20, the required negative pressure V1 of the negative pressure actuator 52, and the control duty ratio D of the negative pressure adjusting valve 54 based on these input signals. The electronic control unit 60 outputs a control signal S to the negative pressure adjusting valve 54 so that the electric control unit 60 is energized with the calculated control duty ratio D. That is, in this embodiment, the electronic control device 60 also functions as a valve control unit that controls the opening degree of the negative pressure adjusting valve 54.

Next, the wastegate valve control process by the electronic control unit 60 will be described. This wastegate valve control process is repeatedly executed at predetermined control cycles when the internal combustion engine 10 is being driven. Further, since the internal combustion engine 10 is driving and the crankshaft 17 is rotating, the vacuum pump 41 using the rotation of the crankshaft 17 as a driving source generates a negative pressure.

As shown in FIG. 2, when the wastegate valve control process is started, the electronic control unit 60 executes the process of step S1. In step S1, the electronic control unit 60 calculates the target boost pressure Pt of the turbocharger 20. Basically, the electronic control unit 60 calculates the target boost pressure Pt as a higher value as the engine speed Ne, the intake flow rate Ga, the vehicle speed SP, and the accelerator pedal depression amount Ac increase. After that, the process of the electronic control unit 60 shifts to step S2.

In step S2, the electronic control unit 60 calculates the required negative pressure V1 of the negative pressure actuator 52. Specifically, the electronic control unit 60 sets the target opening degree of the wastegate valve 28 to a smaller value as the target boost pressure Pt is higher. Then, the electronic control device 60 calculates the negative pressure of the negative pressure actuator 52 required to realize the target opening degree as the required negative pressure V1. As described above, in this embodiment, the larger the negative pressure supplied to the negative pressure actuator 52, the smaller the opening degree of the wastegate valve 28. Therefore, the higher the target supercharging pressure Pt, the larger the required negative pressure V1 of the negative pressure actuator 52 (the lower the pressure). After calculating the required negative pressure V1, the process of the electronic control unit 60 proceeds to step S3.

In step S3, the electronic control unit 60 determines whether or not the brake booster 43 is using the negative pressure of the vacuum pump 41. In this embodiment, the electronic control unit 60 determines that the brake booster 43 is using the negative pressure of the vacuum pump 41 when the pressure Pn in the negative pressure chamber of the brake booster 43 is equal to or higher than the reference value Px. .. On the other hand, when the pressure Pn in the negative pressure chamber of the brake booster 43 is less than the reference value Px, the electronic control unit 60 determines that the brake booster 43 is not using the negative pressure of the vacuum pump 41. The reference value Px is a value calculated according to the engine rotation speed Ne, and is set as a value slightly larger than the pressure generated when the vacuum pump 41 generates a negative pressure. That is, the reference value Px is set to a value at which it can be determined that the negative pressure in the brake booster 43 has weakened and the atmospheric pressure has risen. When it is determined that the negative pressure is being used (YES in step S3), the process of the electronic control device 60 shifts to step S4.

In step S4, the electronic control unit 60 calculates the required negative pressure final value V2 by adding a predetermined predetermined value α to the required negative pressure V1 calculated in step S2. In this embodiment, the specified value α is a predetermined positive value obtained by performing a test or a simulation. For example, the specified value α is obtained by the following test. In this test, under the same other conditions, the negative pressure in the negative pressure actuator 52 was measured when the brake booster 43 used the negative pressure of the vacuum pump 41 and when it was not used, and both were measured. Calculate the difference between. The absolute value of this difference can be defined as the above-mentioned specified value α.

On the other hand, when it is determined in step S3 that the negative pressure is not used (NO in step S3), the processing of the electronic control unit 60 shifts to step S5. In step S5, the electronic control unit 60 sets the required negative pressure V1 calculated in step S2 as it is as the required negative pressure final value V2.

When the required negative pressure final value V2 is calculated in step S4 or step S5, the processing of the electronic control unit 60 shifts to step S6. In step S6, the electronic control unit 60 calculates the control duty ratio D of the negative pressure adjusting valve 54 according to the calculated required final negative pressure value V2. Specifically, the electronic control unit 60 calculates the control duty ratio D to a larger ratio as the required final negative pressure value V2 is larger, and controls as the engine speed Ne is higher and the negative pressure that the vacuum pump 41 can generate is larger. Calculate the duty ratio D small. After that, the process of the electronic control unit 60 shifts to step S7.

In step S7, the electronic control device 60 outputs a control signal S to the negative pressure adjusting valve 54 so that the negative pressure adjusting valve 54 is driven by the control duty ratio D calculated in step S6. By driving the negative pressure adjusting valve 54, the negative pressure inside the negative pressure actuator 52 becomes close to the required negative pressure V1, and the opening degree of the wastegate valve 28 also becomes close to the target opening degree. As a result, the actual supercharging pressure Pa detected by the supercharging pressure sensor 34 also becomes close to the target supercharging pressure Pt. After driving the negative pressure adjusting valve 54, the process of the electronic control unit 60 shifts to step S8.

In step S8, the electronic control unit 60 calculates the feedback value FB of the control duty ratio D. Specifically, when the actual supercharging pressure Pa at the time of executing step S8 is the same as the target supercharging pressure Pt, the electronic control unit 60 calculates the feedback value FB to “0%”. Further, when the actual supercharging pressure Pa at the time of executing step S8 is smaller than the target supercharging pressure Pt, the electronic control unit 60 calculates the feedback value FB to a positive value. On the contrary, when the actual supercharging pressure Pa at the time of executing step S8 is larger than the target supercharging pressure Pt, the electronic control unit 60 calculates the feedback value FB to a negative value. After calculating the feedback value FB, the process of the electronic control unit 60 shifts to step S9.

In step S9, the electronic control device 60 feedback-controls the negative pressure adjusting valve 54. Specifically, the electronic control unit 60 calculates a new control duty ratio D by adding the feedback value FB calculated in step S8 to the control duty ratio D calculated in step S6. Then, the electronic control unit 60 outputs a new control signal S to the negative pressure adjusting valve 54 so that the negative pressure adjusting valve 54 is driven by the new control duty ratio D. In response to the feedback control of the negative pressure adjusting valve 54, the negative pressure inside the negative pressure actuator 52 and the opening degree of the wastegate valve 28 are also feedback controlled. After that, one cycle of a series of wastegate valve control processes is completed, and a new wastegate valve control process is executed again.

The operation of this embodiment will be described.
In the above embodiment, when the internal combustion engine 10 is driven and the crankshaft 17 rotates, the vacuum pump 41 operates to generate a negative pressure according to the rotation speed of the crankshaft 17, that is, the engine rotation speed Ne. The negative pressure generated by the vacuum pump 41 is supplied to the brake booster 43 via the first negative pressure supply path 42. When the user of the vehicle depresses the brake pedal 44 and then returns the brake pedal 44 to its original position, the negative pressure in the negative pressure chamber of the brake booster 43 is temporarily weakened. At this time, the negative pressure in the hydraulic chamber of the brake booster 43 is returned to the required negative pressure by supplying the negative pressure from the vacuum pump 41.

On the other hand, the negative pressure of the vacuum pump 41 is also supplied to the negative pressure actuator 52 of the wastegate valve 28 via the second negative pressure supply path 51. Then, by adjusting the opening degree of the negative pressure adjusting valve 54 provided in the second negative pressure supply path 51, the negative pressure supplied to the negative pressure actuator 52 is adjusted, and the negative pressure of the negative pressure actuator 52 is adjusted. Is controlled to the desired negative pressure. As described above, in the present embodiment, the two negative pressure actuators are operating with the same vacuum pump 41 as the negative pressure source.

The effect of this embodiment will be described.
As described above, the vacuum pump 41 generates a negative pressure according to the engine speed Ne. Here, when the user of the vehicle depresses the brake pedal 44, the negative pressure in the negative pressure chamber of the brake booster 43 is temporarily weakened, and the negative pressure of the vacuum pump 41 is supplied to the brake booster 43. Therefore, the negative pressure in the vacuum pump 41 is also temporarily weakened.

Here, it is assumed that the vacuum pump 41 is generating a negative pressure according to the engine speed Ne, and the control duty ratio D of the negative pressure adjusting valve 54 is calculated. In this case, as in the above example, when the brake booster 43 uses the negative pressure of the vacuum pump 41 and the negative pressure in the vacuum pump 41 is weakened, the negative pressure is weaker than the actual negative pressure of the vacuum pump 41. The control duty ratio D of the negative pressure adjusting valve 54 is calculated on the premise of pressure. Then, when the negative pressure adjusting valve 54 is driven with such a control duty ratio D, the negative pressure in the negative pressure actuator 52 becomes insufficient, and the wastegate valve 28 cannot be controlled to the target opening degree.

In the present embodiment, when the pressure Pn in the negative pressure chamber of the brake booster 43 is equal to or higher than the reference value Px, the negative pressure of the brake booster 43 weakens and the brake booster 43 uses the negative pressure of the vacuum pump 41. Is determined. Then, when the brake booster 43 uses a negative pressure, the specified value α is added to the required negative pressure V1 of the negative pressure actuator 52 to calculate the required negative pressure final value V2. Then, in order to realize the required final negative pressure value V2, the control duty ratio D of the negative pressure adjusting valve 54 is set to a large value, and the opening degree of the negative pressure adjusting valve 54 becomes large.

Here, the above-mentioned specified value α is the negative pressure in the negative pressure actuator 52 when the brake booster 43 uses the negative pressure of the vacuum pump 41 and the negative pressure in the negative pressure actuator 52 when it is not used. Is sought as the difference between. That is, when the brake booster 43 uses the negative pressure, if the negative pressure adjusting valve 54 is controlled so that the negative pressure of the negative pressure actuator 52 becomes the required negative pressure V1, the negative pressure actuator 52 actually becomes The negative pressure is approximately "required negative pressure V1-specified value α".

In this respect, in the present embodiment, when the brake booster 43 uses a negative pressure, as described above, the negative pressure of the negative pressure actuator 52 is not the required negative pressure V1 but the required negative pressure final value V2 ( = Required negative pressure V1 + specified value α) is controlled. Therefore, even if the actual negative pressure of the negative pressure actuator 52 becomes a value smaller than the required final value V2 by a specified value α, as a result, the negative pressure of the negative pressure actuator 52 is the original required value. It is controlled to a required negative pressure V1 or a sufficient negative pressure close to it. Therefore, it is unlikely that the negative pressure actuator 52 will be insufficient in negative pressure and the wastegate valve 28 cannot be appropriately controlled.

As described above, in the present embodiment, even when the brake booster 43 uses the negative pressure, it is unlikely that the negative pressure of the negative pressure actuator 52 will be insufficient. However, depending on the value of the specified value α, it is not always possible to precisely control the actual negative pressure of the negative pressure actuator 52 to the required negative pressure V1. If the required negative pressure V1 cannot be precisely controlled, the opening degree of the wastegate valve 28, and eventually the boost pressure of the turbocharger 20, cannot be precisely controlled.

Therefore, in the present embodiment, after the negative pressure adjusting valve 54 is driven so that the negative pressure of the negative pressure actuator 52 becomes the required final value V2, the difference between the target boost pressure Pt and the actual supercharging pressure Pa. The negative pressure adjusting valve 54 is feedback-controlled based on the above. Therefore, in the present embodiment, the actual supercharging pressure Pa can be quickly converged to the target supercharging pressure Pt as compared with the case where the negative pressure adjusting valve 54 is simply controlled based on the required final negative pressure value V2.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the above embodiment, the negative pressure adjusting valve for the brake booster 43 may be attached to the first negative pressure supply path 42. In this case, when the negative pressure actuator 52 uses negative pressure, the opening degree of the negative pressure adjusting valve for the brake booster 43 may be largely controlled. Whether or not the negative pressure actuator 52 uses negative pressure depends on whether or not the target opening degree of the negative pressure adjusting valve 54 is equal to or more than a certain value and whether or not the actual supercharging pressure Pa is equal to or more than a certain value. It can be judged based on whether or not.

The negative pressure actuator to which the technique of the above embodiment is applied is not limited to the negative pressure actuator 52 of the brake booster 43 and the wastegate valve 28. In addition to these, for example, a negative pressure actuator of an EGR valve provided in an exhaust gas recirculation passage that returns the exhaust gas of the exhaust passage 13 to the intake passage 11, and a negative of a variable intake system that makes the intake path in the intake passage variable. Pressure actuators can be mentioned.

-Three or more negative pressure actuators may be connected to the same vacuum pump 41.
When three or more negative pressure actuators are connected to the same vacuum pump 41, at least one other negative pressure actuator is used depending on whether at least one negative pressure actuator is using negative pressure. It suffices if the required negative pressure of the actuator and the opening degree of the negative pressure adjusting valve can be calculated. If the amount of negative pressure used by a specific negative pressure actuator is small and the effect on other negative pressure actuators is small, other negative pressure actuators may or may not use negative pressure. The required negative pressure of the negative pressure actuator and the opening degree of the negative pressure adjusting valve may be calculated.

When three or more negative pressure actuators are connected to the same vacuum pump 41, the required negative pressure final value of one negative pressure actuator is used, and the other two negative pressure actuators use negative pressure. It can also be calculated based on whether or not it is present. For example, in the above embodiment, it is assumed that the third negative pressure actuator is connected to the vacuum pump 41. In this case, the specified value α is added to the required negative pressure V1 of the negative pressure actuator 52 when the brake booster 43 is using the negative pressure, and the third negative pressure actuator uses the negative pressure. When there is, the specified value β can be added to calculate the required negative pressure final value V2. The same applies when four or more negative pressure actuators are connected.

The vacuum pump 41 does not have to be driven by the rotation of the crankshaft 17. For example, it may be driven by an electric motor.
-The negative pressure supply source is not limited to the vacuum pump 41. For example, if the internal combustion engine 10 is not provided with the turbocharger 20, the intake passage 11 can function as a negative pressure supply source. When the internal combustion engine 10 is being driven, the intake air is sucked into the cylinder 12 in the intake stroke of the internal combustion engine 10, so that the intake passage 11 becomes a corresponding negative pressure. Therefore, the negative pressure can be supplied to the brake booster 43 and other negative pressure actuators by connecting the intake passage 11 to the brake booster 43 and other negative pressure actuators via the negative pressure supply path.

A check valve, an orifice, or the like may be provided in the first negative pressure supply path 42 or the second negative pressure supply path 51, if necessary.
-The determination as to whether or not the brake booster 43 uses negative pressure is not limited to the example of the above embodiment. For example, when the amount of depression of the brake pedal 44 is a certain amount or more, it may be determined that the brake booster 43 is using the negative pressure.

-When the brake booster 43 uses negative pressure, the control duty ratio of the negative pressure adjusting valve 54 is replaced with the process of adding the specified value α to the required negative pressure V1 to calculate the required final negative pressure V2. A predetermined value may be added to D to calculate the final duty ratio. In this modified example, when the brake booster 43 uses negative pressure, the final duty ratio becomes a larger value than when it does not, so that the opening degree of the negative pressure adjusting valve 54 is adjusted accordingly. Greatly controlled.

10 ... Internal combustion engine, 11 ... Intake passage, 12 ... Cylinder, 13 ... Exhaust passage, 15 ... Piston, 16 ... Connecting rod, 17 ... Crankshaft, 18 ... Crank angle sensor, 19 ... Brake disc rotor, 20 ... Turbocharger, 21 ... Turbine section, 22 ... Turbine wheel, 23 ... Bearing section, 24 ... Connecting shaft, 25 ... Compressor section, 26 ... Compressor wheel, 27 ... Wastegate, 28 ... Wastegate valve, 29 ... Link mechanism, 31 ... Airflow meter , 32 ... intercooler, 33 ... throttle valve, 34 ... boost pressure sensor, 35 ... fuel injection valve, 40 ... negative pressure actuator system, 41 ... vacuum pump, 42 ... first negative pressure supply path, 43 ... brake booster, 43a ... pressure sensor, 44 ... brake pedal, 45 ... master cylinder, 46 ... hydraulic circuit, 47 ... brake mechanism, 51 ... second negative pressure supply path, 52 ... negative pressure actuator, 53 ... link mechanism, 54 ... negative pressure adjustment Valve, 60 ... Electronic control unit, 61 ... Vehicle speed sensor, 62 ... Accelerator stroke sensor, CA ... Crank angle, Ne ... Engine speed, Ga ... Intake flow rate, Pa ... Actual boost pressure, Pn ... Negative pressure chamber pressure , SP ... Vehicle speed, Ac ... Accelerator pedal depression amount, S ... Control signal, Pt ... Target boost pressure, Px ... Reference value, V1 ... Required negative pressure, V2 ... Required negative pressure final value, α ... Specified value, D … Control duty ratio, FB… feedback value.

Claims (1)

A negative pressure supply source that generates negative pressure,
A first negative pressure actuator that operates using the negative pressure generated by the negative pressure supply source as a power source,
A second negative pressure actuator different from the first negative pressure actuator that operates by using the negative pressure generated by the negative pressure supply source as a power source,
A negative pressure adjusting valve provided on the negative pressure supply path connecting the negative pressure supply source and the second negative pressure actuator, and
A negative pressure actuator system including a valve control unit that controls the opening degree of the negative pressure adjusting valve according to the required negative pressure of the second negative pressure actuator.
When the first negative pressure actuator uses the negative pressure of the negative pressure supply source, the valve control unit compares with the case where the first negative pressure actuator does not use the negative pressure. A negative pressure actuator system characterized in that the opening degree of the negative pressure adjusting valve is largely controlled.