JP2017171150A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure brake performance by stably supplying negative pressure to a brake booster, in a mechanical negative pressure pump and a negative pressure tank which are operated by drive forces from wheels.SOLUTION: A control device of a vehicle comprises: a brake booster 9 for increasing a pedal-in pedaling force of a brake pedal 7; a negative pressure tank 11 connected to the brake booster 9, supplying negative pressure to the brake booster, and accumulating negative pressure; a mechanical negative pressure pump 13 which is driven by driven wheels 3, and supplies the negative pressure to the negative pressure tank 11; and a negative pressure pump control part 15 for controlling an operation and non-operation of the mechanical negative pressure pump 13 on the basis of a vehicle state.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a vehicle braking device, and more particularly, to a vehicle braking device including a brake booster.

A brake booster (master back, brake booster), which is a device that amplifies the depression force of a brake pedal, is known as a vehicle brake system.
The brake booster has a negative pressure chamber to which negative pressure is supplied, and the pedal effort of the brake pedal is amplified using this negative pressure.

  In an engine-equipped vehicle, a negative pressure is supplied to a negative pressure chamber of a brake booster using a negative pressure pump driven by the engine or a suction negative pressure to the engine. Moreover, in an electric vehicle not equipped with an engine, a negative pressure pump driven by the engine and an intake negative pressure to the engine cannot be used, and therefore, an electric negative pressure pump driven by a vehicle battery is used. .

On the other hand, when the negative pressure that is the boosting source of the brake booster is lowered, there is a problem that the boosting function of the brake booster is lowered.
In Patent Document 1, in a vehicle having a brake booster that uses suction negative pressure generated based on engine rotation as a boost source, a sensor that detects the negative pressure of the brake booster is provided, and the negative pressure is predetermined while the engine is stopped. It is shown to start the engine when it falls below the value.

JP 2000-310133 A

  By the way, in the case of an electric vehicle, since an engine is not mounted, negative pressure is supplied by an electric negative pressure pump. It becomes impossible to supply power to the 12V battery that is charged by being stepped down by the DC / DC converter. As a result, power supply to the electric negative pressure pump becomes impossible, and there is a possibility that the negative pressure supply to the brake booster is insufficient.

  Further, in the invention disclosed in Patent Document 1 described above, the engine is started when the negative pressure drops below a predetermined value while the engine is stopped. There is a risk of causing it.

  Therefore, in view of the above technical problem, at least one embodiment of the present invention is provided with a mechanical negative pressure pump that is operated by a driving force from a driven wheel, and secures a negative pressure source of a brake booster to achieve a stable brake. An object of the present invention is to provide a braking device for a vehicle capable of obtaining performance.

  (1) A braking device for a vehicle according to at least one embodiment of the present invention is connected to a brake booster that increases the depressing force of a brake pedal by a driver, and is connected to the brake booster to supply negative pressure to the brake booster. The negative pressure tank that accumulates the negative pressure, the mechanical negative pressure pump that is driven by a driven wheel to supply the negative pressure to the negative pressure tank, and the operation and non-operation of the mechanical negative pressure pump are in a vehicle state. And a negative pressure pump control unit that controls based on the above.

  According to the configuration (1), the mechanical negative pressure pump that is driven by the driven wheel and supplies the negative pressure to the negative pressure tank is provided, and the negative pressure pump controller operates the mechanical negative pressure pump to Since negative pressure is stored in the tank, the negative pressure supply to the brake booster is ensured, and the brake performance can be secured.

  (2) In some embodiments, in the configuration (1), the mechanical negative pressure pump includes a turbine pump connected via a clutch provided on an axle of the driven wheel and an intake air of the turbine pump. A throttle valve provided on the upstream side, and the downstream side of the throttle valve is connected to the negative pressure tank.

  According to the configuration (2), the mechanical negative pressure pump can be configured by a simple mechanism and can be compactly installed around the driven wheel. Further, the negative pressure generated by a simple mechanism can be guided to the negative pressure tank and accumulated.

  (3) In some embodiments, in the configuration (2), the negative pressure pump control unit switches between disengagement and connection of the clutch, and also switches opening and closing of the throttle valve, and the mechanical negative pressure pump During the operation, the clutch is connected and the throttle valve is closed to generate the negative pressure downstream of the throttle valve.

  According to the configuration (3), the negative pressure pump controller generates a negative pressure downstream of the throttle valve by connecting the clutch and closing the throttle valve when the mechanical negative pressure pump is operated. Negative pressure can be reliably supplied to the negative pressure tank by simple control when the vehicle is running.

  (4) In some embodiments, in any one of the configurations (1) to (3), the vehicle is an electric vehicle, and the negative pressure is generated using a power source that reduces a voltage of a battery for traveling. An electric negative pressure pump for supplying negative pressure to the tank is provided.

  According to the above configuration (4), even when the battery for running an electric vehicle is in an electric shortage state, it is possible to supply negative pressure to the brake booster, and the brake performance is prevented from being deteriorated to ensure the brake performance. The Therefore, for example, even when the traveling battery is in an electric shortage state, the vehicle is towed because the braking performance is ensured even when the vehicle is towed by another vehicle.

  (5) In some embodiments, in the configuration (4), the negative pressure pump control unit prioritizes negative pressure generation by the mechanical negative pressure pump over negative pressure generation by the electric negative pressure pump. A priority control unit is provided.

  According to the configuration (5), since the priority control unit that prioritizes the generation of the negative pressure by the mechanical negative pressure pump over the generation of the negative pressure by the electric negative pressure pump is provided, the 12V power consumption of the electric negative pressure pump Can be saved, and electricity consumption can be improved. In addition, regenerative braking force is difficult to obtain when the driving battery is nearly fully charged, but even in such a case, the brake booster operates reliably due to the negative pressure accumulated in the negative pressure tank, ensuring braking performance it can.

(6) In some embodiments, in any one of the configurations (1) to (5), the vehicle state is a deceleration request state by a driver, and the negative pressure pump control unit is A deceleration determination control unit that operates the mechanical negative pressure pump in the case of a deceleration request greater than or equal to a value is provided.
According to the above configuration (6), the mechanical negative pressure pump is operated to accumulate pressure in the negative pressure tank when the driver requests deceleration more than a predetermined value, so that the negative pressure supply to the brake booster is ensured and the braking performance is improved. Reduction is prevented.

  (7) In some embodiments, in any one of the configurations (1) to (6), the vehicle state is a downhill running state, and the negative pressure pump control unit has a predetermined gradient. In the case of the above-mentioned downhill, the downhill determination control part which operates the said mechanical negative pressure pump is provided.

  According to the configuration (7), the mechanical negative pressure pump is operated to accumulate pressure in the negative pressure tank in the case of a downhill of a predetermined gradient or more, so that the negative pressure supply to the brake booster is ensured and the brake performance is reduced Is prevented.

  (8) In some embodiments, in any one of the configurations (1) to (7), the vehicle state is a negative pressure state of the negative pressure tank, and the negative pressure pump control unit is A negative pressure determination control unit that operates the mechanical negative pressure pump when the negative pressure state is equal to or less than a predetermined threshold value is provided.

  According to the configuration (8), when the negative pressure state of the negative pressure tank is equal to or lower than the predetermined threshold value, the mechanical negative pressure pump is operated to accumulate pressure in the negative pressure tank. This ensures the brake performance is prevented from being lowered.

  (9) In some embodiments, in the configuration of the configuration (4), the vehicle state is a charged state of the battery for traveling, and the negative pressure pump control unit is configured such that the charged state is out of a predetermined range. In some cases, a charge determination control unit for operating the mechanical negative pressure pump is provided.

  According to the configuration (8), when the state of charge of the traveling battery is out of the predetermined range, that is, below the predetermined value, the state of charge is deteriorated, so the mechanical negative pressure pump is operated. When the value is equal to or greater than the predetermined value, regenerative braking cannot be obtained near full charge, and the overcharge is caused to cause deterioration of the traveling battery, so that the mechanical negative pressure pump is operated. Thereby, it is possible to ensure the brake performance and the performance of the traveling battery.

  According to at least one embodiment of the present invention, the brake performance is improved by including a mechanical negative pressure pump and a negative pressure tank that are operated by a driving force from the wheels, and stably supplying negative pressure to the brake booster. Can be secured.

1 is an overall schematic configuration diagram of a vehicle braking device according to an embodiment of the present invention. It is a front view schematic diagram from the vehicle front around a driven wheel. It is a planar view schematic diagram from the upper periphery of a driven wheel. It is a block diagram of the negative pressure pump control unit. It is a control flowchart of a negative pressure pump control part. It is a flowchart of a subroutine of negative pressure tank pressure accumulation. 1 is an overall schematic configuration diagram of a vehicle braking device according to an embodiment of the present invention.

Several embodiments of the present invention will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in these embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Only.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of other constituent elements.

A vehicle braking apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
This embodiment shows an example of an electric vehicle driven by an electric motor. A travel motor (not shown) is driven by a travel battery (high voltage source) 1, the rear wheel side is a drive wheel, and the front wheel side is a driven wheel 3.

  FIG. 1 shows an overall schematic configuration of a vehicle braking device 5. The configuration related to the braking device 5 includes a brake booster 9 that increases the depressing force of the brake pedal 7 by the driver, a negative pressure tank that is connected to the brake booster 9 and supplies negative pressure to the brake booster 9 and accumulates negative pressure. 11.

  Further, the braking device 5 includes a mechanical negative pressure pump 13 that is driven by the driven wheel 3 to supply negative pressure to the negative pressure tank 11, and the operation and non-operation of the mechanical negative pressure pump 13 including the vehicle running state. A negative pressure pump control unit 15 that controls the vehicle based on the vehicle state.

The brake booster 9 has two pressure chambers partitioned by a diaphragm. Negative pressure is supplied to the two pressure chambers, and the inside thereof is basically negative pressure. When the brake pedal 7 is depressed, one pressure chamber is opened to the atmosphere, and a pressure difference is generated between the two pressure chambers. As a result, the depression force of the brake pedal 7 is amplified by this pressure difference and transmitted to the master cylinder 17.
The master cylinder 17 generates a brake hydraulic pressure corresponding to the depression amount of the brake pedal 7. The generated hydraulic pressure is distributed by the hydro unit 19 to the front wheel side which is the driven wheel 3 and the rear wheel side which is the driving wheel, and is supplied to the front brake caliper 21 and a rear brake caliper (not shown).

The negative pressure chamber 23 of the brake booster 9 and the negative pressure tank 11 are connected by a negative pressure pipe 25.
A mechanical negative pressure pump 13 for supplying negative pressure to the negative pressure tank 11 is provided on an axle 27 of the driven wheel 3 as shown in FIG. Clutch) 29, a turbine pump 31 connected via the electromagnetic clutch 29, and a throttle valve 33 provided on the intake upstream side of the turbine pump 31.

  As shown in FIG. 1, the turbine pump 31 is configured by combining a suction side casing 37 provided with a suction port 35 and a discharge port side casing 41 provided with a discharge port 39. An impeller 43 is accommodated in the radial center of the discharge port side casing 41. The impeller 43 has a rotation shaft 45 provided coaxially with an axle 27 that rotates when the driven wheel 3 receives a rotational force from the road surface. The rotation shaft 45 can be connected to the axle 27 via an electromagnetic clutch 29. It has become.

  A suction duct 47 is connected to the suction port 35 opened in the axial direction of the rotary shaft 45, and a discharge duct 49 is connected to the discharge port 39 opened in the radial direction. The air sucked from the suction port 35 (intake air) is sucked out and pushed out so as to be discharged from the discharge port 39 by the rotation of the impeller 43. Note that the end of the discharge duct 49 opposite to the discharge port 39 is open to the atmosphere.

  A suction manifold 51 is provided on the intake upstream side of the suction duct 47. The suction manifold 51 has a function of collecting negative pressure from the left and right mechanical negative pressure pumps 13 driven by the left and right driven wheels 3 to equalize the negative pressure.

  A throttle valve body 53 is provided on the intake upstream side of the intake manifold 51, and a throttle valve 33 is installed in a throat portion where the cross section of the intake passage 54 is narrowed. The intake passage 54 is opened and closed by the throttle valve 33. Is done. A throttle actuator 57 that opens and closes the throttle valve 33 is provided. The opening / closing opening degree of the throttle valve 33 is switched between full opening and a predetermined throttle angle (closed state).

  An air cleaner 59 for removing dust and dirt in the atmosphere is installed on the intake upstream side of the throttle valve body 53, and air is introduced into the throttle valve body 53 through the air cleaner 59.

  Further, the suction manifold 51 and the negative pressure tank 11 are connected by a negative pressure pipe 61. In the negative pressure pipe 61, an electromagnetic solenoid 63 and a check valve 65 are installed in series from the suction manifold 51 side to the negative pressure tank 11 side. The electromagnetic solenoid 63 is controlled to open and shut off the negative pressure pipe 61, and the check valve 65 allows only the flow from the negative pressure tank 11 to the suction manifold 51 side.

2 and 3 show an arrangement example in which the mechanical negative pressure pump 13 is arranged around the driven wheel 3.
FIG. 2 is a front view schematic diagram from the front of the vehicle around the driven wheel 3, and FIG. 3 is a plan schematic diagram from above the periphery of the driven wheel 3.
As shown in FIG. 2, components such as a strut 67, a lower arm 69, and a stabilizer 71 that constitute a front suspension mechanism are installed, and a steering mechanism 73 is installed.

  The axle 27 is rotatably supported by a steering knuckle (hub carrier) (not shown), and an electromagnetic clutch 29 and a turbine pump 31 are attached to the steering knuckle. For this reason, the electromagnetic clutch 29 and the turbine pump 31 are also mounted so that the direction of the rotating shaft 45 of the turbine pump 31 swings in accordance with the steering direction as the driven wheel 3 is steered in response to the steering action of the steering system.

The suction ducts 47 are respectively provided on the left and right sides so as to be connected to the left and right turbine pumps 31.
A suction manifold 51 is provided extending in the vehicle width direction at the center in the vehicle width direction. Left and right suction ducts 47 are connected to both ends of the suction manifold 51.
The suction duct 47 is made of a flexible material so as to be able to move following the swing of the turbine pump 31 along with steering, and has a bellows-like cross-sectional shape (not shown).

  As shown in FIGS. 2 and 3, a throttle valve body 53 is erected on the upper surface of the suction manifold 51, and is provided in a substantially symmetrical position on the left and right sides with respect to the center position in the vehicle width direction. A throttle valve 33 is installed in the throttle valve body 53. An air cleaner 59 is provided at the upper end of the throttle valve body 53.

  As shown in FIGS. 2 and 3, a negative pressure tank 11 is installed above the suction manifold 51 and extends in the vehicle width direction on the vehicle rear side. Negative pressure pipes 61 are connected to each other. The negative pressure pipes 61 that connect the suction manifold 51 and the negative pressure tank 11 are provided on the left and right sides, and an electromagnetic solenoid 63 and a check valve 65 are installed in each negative pressure pipe 61. Note that the negative pressure pipes 61 may not be provided on the left and right sides but may be one.

  The negative pressure pump control unit 15 includes a signal input unit, a signal output unit, a storage unit, a calculation unit, and the like (not shown). A negative pressure signal in the suction manifold 51 is input from the pressure sensor 75 to the signal input unit, The negative pressure signal in the negative pressure tank 11 is input from the pressure sensor 77, the depression state of the brake pedal 7 is input from the pedal stroke sensor 79, and the road surface inclination signal is input from the inclination sensor 81 mounted on the vehicle body. A vehicle speed signal is input from the sensor 83.

Then, the signal output unit outputs an opening / closing signal to the throttle actuator 57, outputs a disconnection / connection signal to the electromagnetic clutch 29, and outputs an opening / closing signal to the electromagnetic solenoid 63.
When the mechanical negative pressure pump 13 is operated, the electromagnetic clutch 29 is connected, the throttle valve 33 is closed, the electromagnetic solenoid 63 is opened, a negative pressure is generated downstream of the throttle valve 33, and the negative pressure is reduced to the negative pressure tank. 11 is supplied. The connection of the electromagnetic clutch 29 and the closing operation of the throttle valve 33 operate in conjunction with each other.

  According to the present embodiment described above, the mechanical negative pressure pump 13 that is driven by the driven wheel 3 and supplies the negative pressure to the negative pressure tank 11 is provided, and the negative pressure pump control unit 15 operates the mechanical negative pressure pump 13. Thus, since the negative pressure is accumulated in the negative pressure tank 11, the negative pressure supply to the brake booster 9 is ensured, and the brake performance can be secured stably.

In some embodiments, as shown in FIG. 1, an electric negative pressure pump 85 is further provided that supplies negative pressure to the negative pressure tank 11 using a power source obtained by stepping down the power supply voltage of the traveling battery 1.
The power source of the traveling battery (high voltage source) 1 that drives the traveling motor is stepped down to the 12V system by the DC / DC converter 87 to charge the 12V system battery 89 and to the electric negative pressure pump 85. Then, the electric negative pressure pump 85 is operated to generate a negative pressure, and the negative pressure tank 11 is accumulated.
As shown in FIG. 1, a check valve 91 provided with a negative pressure pipe 91 that connects the electric negative pressure pump 85 and the negative pressure tank 11 and allows only a flow from the negative pressure tank 11 to the electric negative pressure pump 85 side. 93 is provided.

  According to such an embodiment, even when the traveling battery 1 falls into an electric shortage state, since the negative pressure is secured in the negative pressure tank 11 by the mechanical negative pressure pump 13, the negative pressure to the brake booster 9 is ensured. This makes it possible to prevent the deterioration of the brake performance and ensure the brake performance. Therefore, for example, even when the traveling battery is in an electric shortage state, the vehicle is towed because the braking performance is ensured even when the vehicle is towed by another vehicle.

  In some embodiments, the negative pressure pump control unit 15 includes a priority control unit 95 as shown in FIG. 4, and the priority control unit 95 has priority over the negative pressure generation by the electric negative pressure pump 85. Control is performed so that negative pressure is generated by the mechanical negative pressure pump 13. Further, as shown in FIG. 1, signals such as whether or not the electric negative pressure pump 85 is in an operating state from the electric negative pressure pump 85 and an operating condition for operating the electric negative pressure pump 85 are input to the negative pressure pump control unit 15. Is done. For example, the priority control unit 95 gives priority to the operation of the mechanical negative pressure pump 13 when the operating state and operating conditions of the electric negative pressure pump 85 overlap with the operating state and operating conditions of the mechanical negative pressure pump 13. Therefore, the electric negative pressure pump 85 is not operated.

According to such an embodiment, since the negative pressure is generated by the mechanical negative pressure pump 13 in preference to the negative pressure generated by the electric negative pressure pump 85, the 12V system that supplies power to the electric negative pressure pump 85 is used. Power consumption can be saved, and power consumption can be improved.
In addition, since the number of operations of the electric negative pressure pump 85 is reduced, the operation noise of the electric negative pressure pump 85 is reduced and the comfort level of the occupant is increased. Although it is difficult to obtain a regenerative braking force when the traveling battery 1 is nearly fully charged, even in such a case, the brake booster 9 is reliably operated by the negative pressure accumulated in the negative pressure tank. It can be secured.

In some embodiments, as shown in FIG. 4, the negative pressure pump control unit 15 includes a deceleration determination control unit 97, a downhill determination control unit 99, a negative pressure determination control unit 101, and a charge determination control unit 103. In addition, as shown in FIG. 1, a signal indicating the state of charge (SOC) of the traveling battery 1 is input from the state-of-charge detecting unit 105.
The negative pressure pump control unit 15 controls the operation of the mechanical negative pressure pump 13 in accordance with the flowcharts shown in FIGS.

  First, in step S <b> 1, it is determined based on a signal from the vehicle speed sensor 83 whether the vehicle is running. If the vehicle is traveling, it is determined in step S2 based on signals from the pedal stroke sensor 79 of the brake pedal 7 and the vehicle speed sensor 83 whether or not a brake operation has been performed. For example, when the vehicle speed is equal to or higher than a predetermined value and the operation amount of the brake pedal is equal to or higher than the predetermined value, it is determined that the driver has made a normal deceleration operation, that is, a deceleration request equal to or higher than the predetermined value. In addition, based on the signal from the pedal stroke sensor 79 of the brake pedal 7, when the operation amount changing speed is a certain value or more, it may be determined as sudden braking and excluded from the determination of the brake operation in step S2.

  If YES in step S2, the process proceeds to step S3, the electromagnetic clutch 29 is turned on (connected), the throttle valve 33 is closed to the throttle position in step S4, and the pressure accumulation in the negative pressure tank 11 is increased in step S5. Run. By these steps S <b> 3 to S <b> 5, the mechanical negative pressure pump 13 is operated and negative pressure is accumulated in the negative pressure tank 11. And it returns to step S1 again and repeats a process.

  Here, the subroutine of the negative pressure tank accumulation in step S5 will be described. As shown in FIG. 6, first, in step S11, the negative pressure P1 in the negative pressure tank 11 is detected by the pressure sensor 77, and in step S12, the negative pressure P2 in the suction manifold 51 on the downstream side of the throttle valve 33 is detected. Detected by the pressure sensor 75 provided in the suction manifold 51. If the negative pressure P2 exceeds the negative pressure P1 in step S13, the process proceeds to step S14, where the electromagnetic solenoid 63 is opened, The negative pressure is guided to the negative pressure tank 11. When the negative pressure P2 is smaller than the negative pressure P1, the process proceeds to step S15 and the electromagnetic solenoid is in a closed state. This is because the inside of the negative pressure tank 11 cannot be further reduced.

  Returning to the flowchart of FIG. 5, when the brake operation is not performed by the driver in step S <b> 2, the process proceeds to step S <b> 6 to determine the downhill of the travel path. Based on the signal from the inclination sensor 81, it is determined whether the inclination angle is a downhill inclination of a predetermined value or more. For example, when the inclination is equal to or greater than a predetermined inclination angle and is detected continuously for a predetermined time or more, it is determined that the vehicle is a downhill, and the operations of the mechanical negative pressure pump 13 are performed by executing steps S3 to S5. Thus, a negative pressure is accumulated in the negative pressure tank 11.

  If it is determined in step S6 that the travel path is not a downhill of a predetermined value or more, the process proceeds to step S7 to determine whether or not the negative pressure in the negative pressure tank 11 is equal to or lower than a predetermined threshold value. When the negative pressure is equal to or less than the threshold value, steps S3 to S5 are executed, and the negative pressure is stored in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13. The predetermined threshold value is a minimum negative pressure value that can amplify the depressing force of the brake pedal 7 that is a function of the brake booster 9 and transmit it to the master cylinder 17.

  When it is determined in step S7 that the negative pressure is not less than the predetermined value, the process proceeds to step S8, where the charging rate (SOC) of the traveling battery 1 is 20 to 20% with respect to a predetermined range, for example, 100% full charge. If it is determined that it is 90% and it is not within the predetermined range, steps S3 to S5 are executed, and negative pressure is accumulated in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13. If it is within the predetermined range, the process ends.

  According to such an embodiment, as shown in steps S <b> 2 to S <b> 5, it is determined whether or not a brake operation has been performed, and the negative pressure is stored in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13. Is executed by the deceleration determination control unit 97. By this control, the mechanical negative pressure pump 13 is operated to accumulate pressure in the negative pressure tank 11 when the driver requests deceleration more than a predetermined value, so that the negative pressure supply to the brake booster 9 is ensured and the braking performance is improved. Reduction is prevented.

  Further, as shown in steps S6 and S3 to S5, the control for determining whether or not the vehicle is downhill and accumulating the negative pressure in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13 is a downhill determination control unit. 99. This control activates the mechanical negative pressure pump 13 to accumulate pressure in the negative pressure tank 11 when the downhill slope is equal to or greater than a predetermined value, so that the negative pressure supply to the brake booster 9 is ensured and the brake performance is reduced. Is prevented.

  Further, as shown in steps S7 and S3 to S5, it is determined whether the pressure in the negative pressure tank 11 is equal to or less than a predetermined threshold value, and the negative pressure is accumulated in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13. The control is executed by the negative pressure determination control unit 101. By this control, when the negative pressure in the negative pressure tank 11 is equal to or lower than the threshold value, the mechanical negative pressure pump 13 is operated to accumulate pressure in the negative pressure tank 11, so that the negative pressure supply to the brake booster 9 is ensured and the brake Performance degradation is prevented.

  Further, as shown in steps S8 and S3 to S5, it is determined whether the state of charge (SOC) of the traveling battery 1 is within a predetermined range, and the negative pressure is stored in the negative pressure tank 11 by the operation of the mechanical negative pressure pump 13. The control to perform is executed by the charge determination control unit 103. By this control, when the state of charge is equal to or less than the predetermined value, it is determined that the state of charge is deteriorated, and the mechanical negative pressure pump 13 is operated. Further, when the value is equal to or greater than the predetermined value, regenerative braking is not obtained near full charge, and overcharge occurs and the traveling battery 1 is deteriorated, so that the mechanical negative pressure pump 13 is operated. Thereby, it is possible to ensure the brake performance and the performance of the traveling battery 1.

In some embodiments, as shown in FIG. 7, a vehicle including an engine 107 is shown. In the overall schematic configuration diagram of the vehicle braking device shown in FIG. 1, the intake negative pressure of the engine 107 is guided to the negative pressure tank 11 instead of the electric negative pressure pump 85.
The operation control of the mechanical negative pressure pump 13 by the negative pressure pump control unit 15 is performed based on the determination based on the state of charge of the traveling battery 1 in step S8 in the flowchart shown in FIG. It is the same as that except control.

  According to such an embodiment, the negative pressure supply to the brake booster 9 is achieved by including the mechanical negative pressure pump 13 and the negative pressure tank 11 that are operated by the driving force from the driven wheel 3 even in a vehicle equipped with an engine. Can be performed stably, and braking performance can be secured.

  According to at least one embodiment of the present invention, the brake performance is provided by including a mechanical negative pressure pump and a negative pressure tank that are operated by a driving force from a driven wheel, and stably supplying negative pressure to the brake booster. This is suitable for use in a vehicle braking device.

DESCRIPTION OF SYMBOLS 1 Battery for driving | running | working 3 Driven wheel 7 Brake pedal 9 Brake booster 11 Negative pressure tank 13 Mechanical negative pressure pump 15 Negative pressure pump control part 25, 61, 91 Negative pressure piping 29 Electromagnetic clutch (clutch)
31 Turbine pump 33 Throttle valve 51 Suction manifold 53 Throttle valve body 59 Air cleaner 61 Electromagnetic solenoid 65, 93 Check valve 75, 77 Pressure sensor 81 Inclination sensor 83 Vehicle speed sensor 85 Electric negative pressure pump 87 DC / DC converter 89 12V system battery 97 Deceleration determination control unit 99 Downhill determination control unit 101 Negative pressure determination control unit 103 Charge determination control unit 105 Charging state detection means

Claims (9)

A brake booster that increases the depressing force of the brake pedal by the driver,
A negative pressure tank connected to the brake booster and supplying negative pressure to the brake booster, and accumulating the negative pressure;
A mechanical negative pressure pump driven by a driven wheel to supply the negative pressure to the negative pressure tank;
A vehicular braking apparatus comprising: a negative pressure pump control unit that controls operation and non-operation of the mechanical negative pressure pump based on a vehicle state.   The mechanical negative pressure pump has a turbine pump connected via a clutch provided on an axle of the driven wheel, and a throttle valve provided on the intake upstream side of the turbine pump, and is provided downstream of the throttle valve. The vehicle braking device according to claim 1, wherein a side and the negative pressure tank are connected to each other.   The negative pressure pump control unit switches between disconnection and connection of the clutch, and switches opening and closing of the throttle valve, and when the mechanical negative pressure pump is operated, connects the clutch and closes the throttle valve, The vehicle braking device according to claim 2, wherein the negative pressure is generated downstream of the throttle valve.   4. The electric vehicle according to claim 1, wherein the vehicle is an electric vehicle, and includes an electric negative pressure pump that supplies a negative pressure to the negative pressure tank using a power source that reduces a voltage of a battery for traveling. The vehicle braking device according to the item.   The said negative pressure pump control part was provided with the priority control part which gives priority to the negative pressure generation by the said mechanical negative pressure pump over the negative pressure generation by the said electric negative pressure pump. Vehicle braking device.   The vehicle state is a deceleration request state by a driver, and the negative pressure pump control unit includes a deceleration determination control unit that operates the mechanical negative pressure pump when a deceleration request greater than a predetermined value is requested. The vehicle braking device according to any one of claims 1 to 5.   The vehicle state is a downhill running state, and the negative pressure pump control unit includes a downhill determination control unit that operates the mechanical negative pressure pump when the downhill is equal to or greater than a predetermined gradient. The vehicle braking device according to any one of claims 1 to 6.   The vehicle state is a negative pressure state of the negative pressure tank, and the negative pressure pump control unit is configured to operate the mechanical negative pressure pump when the negative pressure state is a predetermined threshold value or less. The vehicle braking device according to any one of claims 1 to 7, further comprising:   The vehicle state is a state of charge of the battery for traveling, and the negative pressure pump control unit includes a charge determination control unit that operates the mechanical negative pressure pump when the state of charge is outside a predetermined range. The vehicle braking device according to claim 4, wherein the vehicle braking device is a vehicle.

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