JPH066424B2 - Vehicle propulsion control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle propulsion control device, and in particular, a vehicle can be stably driven by suppressing an excessive slip that occurs during starting and acceleration. The present invention relates to a vehicle propulsion control device that can be secured and can be improved in acceleration.

[Prior Art] Conventionally, as a device of this type, for example, Japanese Patent Laid-Open No. 57-2
2948 and JP-A-58-16948 are known.

However, these devices are
In order to perform so-called traction control, a dedicated hydraulic pump unrelated to the master cylinder of the brake is used, and the hydraulic pressure from this pump is applied to the wheel cylinder for braking the wheels.

Therefore, it is necessary to install a new hydraulic pump, which complicates the structure, increases the mounting space, and increases the weight and the production cost.

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, focusing on a hydraulic pump connected to a hydraulic booster of a brake device,
An object of the present invention is to provide a propulsion control device for a vehicle, which utilizes the hydraulic pressure from this pump to prevent acceleration slip with a simple configuration.

[Means for Solving Problems] The present invention made to solve the above problems is, as shown in FIG. 1, a hydraulic pressure that is connected to a hydraulic pump and that amplifies the pedal effort of the brake pedal. The booster, the master cylinder that receives the hydraulic pressure from the hydraulic booster, the wheel cylinder that receives the hydraulic pressure from the master cylinder through the cut valve to brake the driving wheels, and the hydraulic pressure of the wheel cylinder A control valve for increasing or decreasing pressure, a switching valve having an input side connected to the hydraulic pump and an output side connected to the switching control input section of the cut valve and the control valve, and the wheel from the switching valve via the control valve A throttle provided in the hydraulic pressure transmission path to the cylinder, a wheel speed sensor that detects the number of rotations of the wheel, and the acceleration slip state of the drive wheel based on the detection signal from the wheel speed sensor. And the electronic control unit for sending the first and second control signals to the switching valve and the control valve, respectively, and when the switching valve receives the first control signal, switching of the cut valve is performed. A hydraulic pressure is applied to the control input section to shut off the master cylinder and the wheel cylinder, and when the control valve receives the second control signal, the hydraulic pressure of the wheel cylinder is controlled to increase or decrease. The main point is a propulsion control device for a vehicle.

[Operation] In the present invention configured as described above, when the wheel speed sensor detects an excessive acceleration slip of the driving wheels, the control device determines that the vehicle is in the acceleration slip state and outputs the first and second control signals. Send to the switching valve and control valve respectively. When the switching valve receives the first control signal, hydraulic pressure is applied to the switching control input of the cut valve to disconnect the master cylinder and the wheel cylinder. Further, at this time, the switching valve supplies the hydraulic pressure from the hydraulic pump to the wheel cylinder via the throttle and the control valve. Therefore, the hydraulic pressure is gently supplied to the wheel cylinder via the throttle, and the braking force is gradually applied to the drive wheels. When the control valve receives the second control signal,
The braking force applied to the drive wheels is adjusted by controlling the hydraulic pressure of the wheel cylinders. Therefore, the acceleration slip control of the drive wheels is favorably performed.

Further, in the present invention, since the hydraulic pressure from the hydraulic pump connected to the hydraulic booster is used, it is not necessary to install a new hydraulic pump for acceleration slip control. Therefore, the structure is simplified and the mounting space is reduced.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a hydraulic circuit diagram showing a first embodiment of the present invention,
The anti-skid control is performed together with the vehicle propulsion control. The figure shows a rear-wheel drive vehicle in which the rear wheels W2R and W2L are drive wheels and the front wheels W1L and W1R are driven wheels.

In the figure, 10 is a brake pedal, and 12 is a hydraulic booster that amplifies the pedaling force of the brake pedal 10. A master cylinder 14 is connected to the hydraulic pressure booster 12, and the master cylinder 14 includes first and second hydraulic pressure generating chambers 14a and 14b.

The first hydraulic pressure generating chamber 14a of the master cylinder 14 is provided with the conduit 1
The wheel cylinder 1R of the front wheel W1R and the wheel cylinder 1L of the front wheel W1L communicate with each other via 6.

On the other hand, the second hydraulic pressure generating chamber 14b of the master cylinder 14 is
Pipe line 18, proportional valve 20, cut valve 30R,
The wheel cylinder 2R of the rear wheel W2R and the wheel cylinder 2L of the rear wheel W2L communicate with each other via 30L. The proportional valve 20 is used for the rear wheel W2.
When the braking pressures of R and W2L are equal to or higher than a predetermined value, the hydraulic pressure to the rear wheels W2R and W2L is reduced with respect to the front wheels W1R and W1L at a constant rate so as to be adjusted so as to be an ideal distribution. is there.

The hydraulic booster 12 has lines 38, 39 and a check valve 4
A motor-driven hydraulic pump 42 is connected via 0. The suction side of the hydraulic pump 42 communicates with the reservoir 48 via the check valve 44 and the pipe line 46. Further, an accumulator 50 is connected to the conduit 39. The check valves 40 and 44 have a forward direction in the direction toward the hydraulic booster 12.

The hydraulic pump 42 communicates with one input port of the three-port two-position switching valve 60 via conduits 39 and 52, and one of the two output ports communicates with the reservoir 48. Further, the other output port of the switching valve 60 is connected to the control inputs of the cut valves 30R and 30L via a pipe line 66R indicated by the alternate long and short dash line, and the check valve 65, throttle valves 99R and 99L, and 3 are provided. Port 2 position control valve 36
The rear wheel cylinders 2R and 2L are respectively connected via R and 36L. Further, the other output ports of the three-port two-position control valves 36R and 36L communicate with the reservoir 48.

The switching valve 60 is a spring offset type 3 port 2
When it is a position solenoid valve and is excited by a control signal from an electronic control unit (ECU) 82, it moves from the position shown in FIG. 2 (hereinafter referred to as bypass state (OFF)) to the position on the left side of FIG. 2 (hereinafter referred to as communication state). (ON)).

The cut valves 30R and 30L are hydraulically driven 2-port 2
It is a position valve, and the switching valve 60 allows the conduit 6 shown by the alternate long and short dash line.
When hydraulic pressure is supplied to the control input via 6R, the hydraulic pressure is changed from the position shown in FIG. 2 (hereinafter referred to as the communication state (OFF)) to the second position.
It can be switched to the position on the left side of the figure (hereinafter referred to as the cutoff state (ON)).

The control valves 36R and 36L are spring offset type three-port two-position solenoid valves, and when excited by a control signal of the ECU 82, the position shown in FIG.
F). ) To the position on the left side of FIG. 2 (hereinafter referred to as the bypass state (ON)).

Front wheels (driven wheels) W1R, W1L and rear wheels (driving wheels) W
2R and W2L are provided with driven wheel speed sensors S1L and S1R and driving wheel speed sensors S2R and S2L, which generate pulses according to the rotational speed of the wheels. The brake pedal 10 is provided with a brake switch 84 that is turned on only when the brake pedal 10 is depressed.

As shown in FIG. 3, the ECU 82 is composed of a microcomputer, and 92 is a central processing unit (hereinafter referred to as CPU) 93 for performing calculations such as slip determination, which is a pulse of the speed sensors S1L, S1R, S2L and S2R. A counter for counting the number, 94 is the speed sensor S1L,
An input port for inputting signals of S1R, S2L, S2R and the brake switch 84, 95 is a random access memory (hereinafter referred to as RAM) for temporarily storing calculation results and the like, and 96 stores calculation programs and control data. Read-only memory (hereinafter referred to as ROM), 9
An output port 7 outputs a control signal to the control valves 36L and 36R and the switching valve 60.

That is, the ECU 82 controls the speed sensors S1L and S1.
R, S2L, S2R speed signals are input, slip determination is performed according to the running state, and when slip occurs,
Brake fluid applied to the wheel cylinders 2L, 2R of the rear wheels W2L, W2R shown in FIG. 2 while sending a control signal to the switching valve 60 to switch the valve and output a control signal to the control valves 36L, 36R. The pressure is controlled to switch between the pressure increasing mode and the pressure reducing mode, and an instruction is issued via the output port 97 to suppress the slip.

The operation of this embodiment will be described below with reference to FIG.

(A) During normal braking The switching valve 60 is in the bypass state (OFF), therefore the cut valves 30R and 30L are in the communication state (OFF), and the control valves 36R and 36L are in the communication state (OFF). There is.

When the driver steps on the brake pedal 10 to stop the vehicle, the master cylinder 1 is pressed through the hydraulic booster 12.
The hydraulic pressure from the fourth hydraulic pressure generating chamber 14a is supplied to the front wheel wheel cylinders 1R, 1L via the pipe line 16 to increase the hydraulic pressure in the wheel cylinders 1R, 1L and operate the brake.

On the other hand, the hydraulic pressure from the second hydraulic pressure generation chamber 14b of the master cylinder 14 increases the hydraulic pressure in the rear wheel cylinders 2R and 2L via the pipe 18, the proportional valve 20, and the cut valves 30R and 30L, respectively. And activate the brake. When the hydraulic pressure in the proportional valve 20 exceeds a predetermined value, the pressure reducing action is performed so that the braking force of the rear wheels with respect to the front wheels is ideally distributed. in this case,
That is, during normal braking, the hydraulic pump 42 acts to increase the braking force by supplying hydraulic pressure to the hydraulic booster 12.

(B) During slip control Next, at the time of starting, accelerating, turning, etc., with the brake pedal 10 not being depressed,
The operation of slip control when the rear wheels (driving wheels) W2R and W2L slip will be described.

If excessive slip occurs in the rear wheels W2L, W2R, the ECU 82, which has received the signals from the speed sensors S1L, S1R, S2L, S2R, determines that the rear wheels W2L, W2R are in a slip state and suppresses the slip. , Switching valve 6
0, control valves 36R and 36L. That is, the switching valve 60 is switched to the communicating state (ON) so that the brake hydraulic pressure is applied to the wheel cylinders 2L, 2R on the rear wheel side, and the hydraulic pressures from the hydraulic pump 42 and the accumulator 50 are in the communicating state (OFF). Supply to the wheel cylinders 2R, 2L via the control valves 36R, 36L.

As a result, the rear wheels W2R and W2L are braked, and slip is suppressed. Further, at this time, the hydraulic pressure from the accumulator 50 is gently supplied to the wheel cylinders 2R and 2L via the throttle valves 99R and 99L, so that the braking force is gradually applied to the rear wheels W2R and W2L. Therefore, it is possible to prevent an excessive braking force from being applied to the rear wheels W2R and W2L at the moment when the switching valve 60 is switched to the communication state (ON), and it is possible to favorably suppress the acceleration slip.

Next, as described above, the detailed operation of the slip control will be described below.
This will be described with reference to the hydraulic circuit diagram in the figure and the flowchart in FIG.

In the ECU 82, when a slip control process is started, speed signals are input from the speed sensors S1L, S1R, S2L, S2R, and then, in step 110, the driven wheel speed VV.
Then, in step 112, the driving wheel speed VW is calculated. Then, in step 114, it is determined from the output of the brake switch 84 whether or not the brake pedal 10 is depressed, and when the brake pedal 10 is not depressed, the routine proceeds to step 118, where a slip determination reversal VT is created. Here, the driven wheel speed corresponding to the vehicle speed is multiplied by K (K = 1.1 to 2), and a predetermined speed VO (VO = 0 to 25 km / h) is further added to create the slip determination level VT. That is, VT = K × V
V + VO, and step 120 based on this VT
The drive wheel speed VW is compared with the slip determination level VT. If VW> VT and it is determined that there is slip, the routine proceeds to step 122, where the switching valve 60 is switched to the communication state (ON), and the brake fluid pressure is changed from the hydraulic pump 42 and the accumulator 50 to the switching valve 60. To the control inputs of the cut valves 30R and 30L. As a result, the cut valves 30R and 30L are switched to the closed state (ON), and the master cylinder 14 and the rear wheel wheel cylinder 2 are
The communication between R and 2L is cut off. At the same time, the rear wheel wheel cylinder 2 is passed through the control valves 36R and 36L which are in the communicating state (OFF) of the brake fluid pressures from the hydraulic pump 42 and the accumulator 50 via the switching valve 60.
Send to R, 2L. Then, the routine proceeds to step 124, where the control valves 36R and 36L are shut off (ON) or open (OF).
By performing ON / OFF control of F), the pressure in the rear wheel cylinders 2L, 2R is set to a predetermined pressure, and the rear wheels W2R, W2L are braked to perform slip control. Then, the process returns to step 110, and this routine is repeated.

On the other hand, when it is determined in step 120 that VW ≦ VT, that is, there is no slip, the process proceeds to step 126, the switching valve 60 is switched to the bypass state (OFF), and the process proceeds to step 128 to connect the control valves 36R and 36L. It switches to the state (OFF), returns to the normal braking state, and returns to step 110.

When it is determined in step 114 that the brake pedal 10 is depressed, the routine proceeds to step 116, where antiskid control described in detail below is performed.

(C) Anti-skid control When the pressure in the wheel cylinders 2L, 2R rises due to the same operation as during normal braking described above and the wheels are about to be locked, the ECU 82 that receives signals from the speed sensors S2L, S2R It is determined that the valve is in the locked state, the switching valve 60 is switched to the communicating state (ON), and the hydraulic pressures from the hydraulic pump 42 and the accumulator 50 are cut valves 30R, 30.
L and rear wheel cylinders 2L, 2R. As a result, the cut valves 30R and 30L are switched to the closed state (ON), and the master cylinder 41 and the rear wheel cylinder 2
Communication with L and 2R is cut off. At the same time, the ECU
Reference numeral 82 controls ON / OFF of the control valves 36L, 36R to reduce the pressure in the rear wheel cylinders 2L, 2R and suppress the wheel slip ratio to about 20%. Antiskid control is performed in this manner, and the process returns to step 110.

According to the above-described embodiment of the present invention, the hydraulic pump 42 and the accumulator 50 include the hydraulic booster 1 for brake operation.
2 and hydraulic pressure to the cut valves 30R and 30L through the switching valve 60 to supply the hydraulic pressure to the cut valves 30R and 30R.
The operation of 30L normally shuts off the brake system and supplies brake fluid pressure to the rear wheel cylinders 2R, 2L. That is, in the above configuration, since the hydraulic pump for the hydraulic booster is used, it is not necessary to separately provide a hydraulic pressure source dedicated to the acceleration slip control or the anti-skid control, and the hydraulic circuit can be simplified. Also, the cut valve 30
The R and 30L are hydraulic drive valves that operate by receiving the hydraulic pressure from the switching valve 60, and complicated valves such as solenoid valves are not used, so the valve structure can be simplified.

Next, a second embodiment of the present invention will be described with reference to FIG.

The first embodiment relates to a device that controls only the rear wheels (driving wheels) W2L and W2R, but the second embodiment is the front
The anti-skid control for the rear wheels W1L, W1R, W2L, W2R and the acceleration slip control for the rear wheels (driving wheels) W2L, W2R are also made possible. A hydraulic circuit diagram in this case is shown in FIG. In FIG. 5, the switching valve 60 and the rear wheel brake system are the same as those in the first embodiment, so the description thereof will be omitted. In the front wheel brake system, the first hydraulic pressure generation chamber 14a of the master cylinder 14 communicates with the front wheel cylinders 1R and 1L via the pipe 16, the two-port two-position cut valves 26R and 26L, respectively. Also. The hydraulic booster 12 is connected to the input port of the 3-port 2-position switching valve 62, and one of the two output ports communicates with the reservoir 48. The other output port of the switching valve 62 is connected to the control inputs of the cut valves 26R and 26L via a pipe line 66F indicated by the alternate long and short dash line, and
The check valve 76, the 3-port 2-position control valve 28R, and the check valve 80 are connected to the front-wheel wheel cylinders 1R, 1L via the 3-port 2-position control valve 28L, respectively, and further via the switching valve 60. It is connected to a rear wheel brake system similar to that of the first embodiment. The output ports of the three-port two-position control valves 28R and 28L communicate with the reservoir 48.

The operation of this embodiment will be described below with reference to FIG.

(A) During normal braking The switching valves 60, 62 are in the bypass state (OFF), and the cut valves 26R, 26L, 30R, 30L are in the communication state (OF).
F), and the control valves 28R, 28L, 36R, 36L are in the communicating state (OFF), and the hydraulic pressure from the master cylinder 14 is the wheel cylinders 1L, 1R, 2R of the respective wheels as in the first embodiment. , Operates to add directly to 2L.

(B) During acceleration slip control The switching valve 62 is in the bypass state (OFF) and the cut valve 26
R and 26L are in the communication state (OFF), and the control valve 28
R and 28L are in the communication state (OFF), and the other valves switch the switching valve 60 to the communication state (ON) in the same manner as in the first embodiment, so that the hydraulic pressure from the hydraulic pump 42 is changed. In addition to the rear wheel cylinders 2R, 2L, slip control for the rear wheels (driving wheels) W2L, W2R is performed.

(C) During anti-skid control When the brake pedal 10 is depressed, the pressure in the wheel cylinders 1L, 1R, 2R, 2L rises, and the front and rear wheels W1L, W1R, W2L, W2R try to lock, The speed sensors S1L, S1R, S2L, S2
The ECU 82 receiving the signal from R detects the locked state, switches the switching valve 62 to the communication state (ON), and controls the hydraulic pressure from the hydraulic booster 12 via the switching valve 62 and the pipe line 66F indicated by the alternate long and short dash line. In addition to the cut valves 26R, 26L, and the cut valves 30R, 30L via the switching valves 62, 60 and the conduit 66R shown by the alternate long and short dash line, the respective cut valves are switched to the shut-off state (ON) so that the master cylinder 14 and the front -Disconnect between the rear wheel cylinders 1L, 1R, 2R, 2L. At the same time, the hydraulic pressure from the hydraulic booster 12 is applied to each wheel cylinder via the switching valve 62, that is, via the check valve 76, the control valve 28R and the check valve 80, and the control valve 28L to the front wheel cylinder. To 1R, 1L,
Switching valves 62, 60, check valve 65 and control valves 36R, 3
It is supplied to the rear wheel cylinders 2R, 2L via 6L, respectively.

Therefore, under the condition that the hydraulic pressure of the hydraulic booster 12 is directly applied to the front and rear wheel wheel cylinders 1L, 1R, 2R, 2L, the control valves 28R, 28L, 3 are controlled by the ECU 82.
ON / OFF control 6R and 36L to reduce the pressure in the front and rear wheel cylinders 1L, 1R, 2R and 2L.
Antiskid control is performed to suppress the slip ratio of the rear wheels W1R, W1L, W2R, W2L to about 20%.

According to the second embodiment of the present invention, the switching valve 62 connected to the hydraulic booster 12 and the cut valves 26R, 26L provided between the master cylinder 14 and each wheel cylinder,
30R, 30L and control valves 28R, 28L, 36R,
In the brake hydraulic circuit having an anti-skid control function having 36L, hydraulic pressure sources of the hydraulic booster 12, that is, hydraulic pressures from the hydraulic pump 42 and the accumulator 50 are passed through the switching valve 60 to the rear wheel cylinders 2R, 2L. Also, the acceleration slip control can be performed by supplying to the. That is, the acceleration slip control can be performed by using the anti-skid valve without providing the hydraulic pressure supply source dedicated to the acceleration slip control, the cut valve, and the control valve, so that the hydraulic circuit can be simplified. it can.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. .

[Effects of the Invention] As described in detail above, according to the present invention, since the hydraulic pressure from the hydraulic pump connected to the hydraulic booster is used, acceleration slippage is not required without newly installing a hydraulic pump. Control can be performed. Therefore, while simplifying the structure,
The mounting space can be reduced. Therefore, if the present invention is applied, an increase in weight and production cost can be suppressed.

Further, in the present invention, the hydraulic pressure from the hydraulic pump is gently supplied to the wheel cylinder via the throttle. Therefore, the braking force can be gradually applied to the drive wheels to favorably execute the acceleration slip control. Therefore, good acceleration can be obtained, and the hydraulic pressure amplitude of the wheel cylinder can be reduced to reduce the operating noise.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the constitution of the present invention, FIG. 2 is a hydraulic circuit diagram showing the first embodiment of the present invention, and FIG. 3 is a constitutional view of an electronic control unit (ECU) of the same embodiment. FIG. 4 is a flow chart showing the operation of the same embodiment, and FIG. 5 is a hydraulic circuit diagram showing the second embodiment of the present invention. 10 ... Brake pedal 12 ... Hydraulic booster 14 ... Master cylinder 30L, 30R ... Cut valve 36L, 36R ... 3 port 2 position control valve 42 ... Hydraulic pump 48 ... Reservoir 50 ... Accumulator 60 ... 3 port 2 position switching valve 82 ... Electronic control unit 99L, 99R ... Throttle valve 1L, 1R, 2L, 2R ... Wheel cylinder S1L, S1R ... Driven wheel speed sensor S2L, S2R ... Drive wheel speed sensor W1L, W1R ... Front wheel W2L, W2R ... Rear wheel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Hattori, 1-1, Showa-cho, Kariya city, Aichi Prefecture, Nihon Denso Co., Ltd. (56) References JP-A-54-144557 (JP, A)

Claims (1)

[Claims] 1. A hydraulic booster which is connected to a hydraulic pump and which amplifies the pedaling force of a brake pedal, a master cylinder which receives the hydraulic pressure from this hydraulic booster, and a valve which cuts the hydraulic pressure from this master cylinder. And a control valve for increasing or reducing the hydraulic pressure in the wheel cylinder, an input side connected to the hydraulic pump, and an output side for switching control input of the cut valve and A switching valve connected to the control valve, a throttle provided in a hydraulic pressure transmission path from the switching valve to the wheel cylinder via the control valve, a wheel speed sensor for detecting the rotational speed of the wheel, An electronic that sends the first and second control signals to the switching valve and the control valve, respectively, when it is determined that the driving wheels are in the acceleration slip state based on the detection signals from the wheel speed sensor. A control device is provided, and when the switching valve receives a first control signal, hydraulic pressure is applied to the switching control input portion of the cut valve to disconnect the master cylinder and the wheel cylinder, and A propulsion control device for a vehicle, which is configured to increase / decrease a hydraulic pressure of a wheel cylinder when receiving a control signal of 2.