JP2593413Y2 - Vehicle braking device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking device, and more particularly, to a vehicle braking device that does not cause creep of a vehicle even when the brake pedal is released when the vehicle stops.

[0002]

2. Description of the Related Art Conventionally, a braking device for a vehicle includes a master cylinder which is operated in conjunction with a brake pedal, and operates by sending a pressurized fluid from the master cylinder to each wheel cylinder via a fluid path during braking of the vehicle. It is well known to do so. By the way, in the case of an automatic car,
Normally, when the shift lever is set to a position other than neutral and parking, for example, a drive range, the engine is set to idle at a very low speed if the brake pedal is released even when the vehicle is stopped. It is called.

However, when the vehicle is stopped, the driver accidentally releases his / her foot from the brake pedal while keeping the shift lever in the drive range or the like, causing a rear-end collision or collision without noticing that the vehicle is moving due to creep. It has been reported. For this reason, it has been proposed that the fluid pressure continue to act on each wheel cylinder as long as the driver does not operate the accelerator or the like even when the driver releases his / her foot from the brake pedal while the vehicle is stopped.

As one of the devices, as shown in FIG. 4, an electromagnetic valve 2 is provided in a fluid path 1 connecting a master cylinder and a wheel cylinder, and when the vehicle stops, the electromagnetic valve 2 is operated so that the fluid path 1 is formed. There is known a braking device 4 which is closed to prevent return of pressurized fluid from each wheel cylinder 3.

The conventional braking device 4 operates the electromagnetic valve 2 in response to a vehicle speed sensor 5 installed on the vehicle and a signal from the sensor in order to operate the electromagnetic valve 2 when the vehicle stops. And a control circuit 6. FIG.
Reference numeral 7 denotes a master cylinder which presses oil or the like in conjunction with a brake pedal 8 of the vehicle and supplies the oil or the like to the wheel cylinder 3 of each wheel.

Reference numeral 9 also indicates that the solenoid valve 2 bypasses the solenoid valve installation position of the liquid passage in order to ensure one-way fluid supply from the master cylinder 7 to each wheel cylinder 3 even when the liquid passage 1 is closed. 3 shows a check valve provided in the circuit.

According to such a vehicle braking device 4, when the driver operates the master cylinder 7 by stepping on the brake pedal 8, the pressurized fluid is sent to each wheel cylinder 3 via the liquid passage 1, and Stop the rotation of. When the vehicle stops, the vehicle speed sensor 5 detects this and outputs it to the control circuit 6, which activates the solenoid valve 2 to close the liquid passage 1.

As a result, the pressurized fluid supplied to each wheel cylinder 3 cannot return to the master cylinder 7, so that even if the foot is released from the brake pedal 8, the pressurized fluid remains in each wheel cylinder 3 as it is. It keeps acting and keeps the braking state on the vehicle.

[0009]

In such a conventional vehicle braking device 4, various types of vehicle speed sensors 5 have been used, but none of them has been satisfactory with accuracy. Therefore, it has been proposed to use a power generation type speed sensor as the vehicle speed sensor 5. This power generation type speed sensor outputs a speed signal (FIG. 2A) by generated power that changes depending on the speed of the vehicle, and is known to accurately detect the speed of the vehicle.

However, the speed signal from the power generation type speed sensor is shaped into a waveform by a control circuit, and the speed signal shown in FIG.
As shown in FIG. 2 (c), when the pulse signal waveform is as follows, the pulse signal is not output in a low speed range (approximately 4 km / h), and the pulse signal is not output (point P). There was a problem that it was not possible to determine whether the vehicle was running slowly.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. An electromagnetic valve interposed in a liquid passage by reliably detecting a stopped state of a vehicle using a power generation type speed sensor. To provide a vehicle braking device that appropriately prevents creep when the vehicle stops.

[0012]

The vehicle braking device according to the present invention is provided on a fluid path 1 connecting a master cylinder 7 and a wheel cylinder 3 and an electromagnetic valve 2 for controlling the opening and closing of the fluid path 1.
A speed sensor 12 for detecting a speed signal of the vehicle,
A control device 11 for receiving a signal from the speed sensor 12 to operate the solenoid valve 2;
1 receives a speed signal from the speed sensor 12, calculates a deceleration, estimates a time until the vehicle stops from the deceleration, and outputs an operation signal to the solenoid valve 2.

Further, in the vehicle braking device according to the present invention, the control device 11 calculates a vehicle deceleration from a preset first reference speed value to a second reference speed value, and calculates the vehicle deceleration from this deceleration to the vehicle stop. And outputs an operation signal to the solenoid valve 2.

Further, in the vehicle braking device of the present invention, the second reference speed value set in the control device 11 is set to a speed value immediately before the speed sensor 12 cannot output a speed signal. It is characterized by.

[0015]

According to the vehicle braking device of the present invention, when the driver depresses the brake pedal to stop the vehicle, the vehicle is decelerated. At that time, the control device receives the speed signal from the power generation type speed sensor and calculates the deceleration. Then, the time from the deceleration to the stop of the vehicle is estimated, and an operation signal is output to the solenoid valve to close the liquid path. In this case, the control device determines the deceleration by calculating a vehicle speed value from a preset first reference speed value to a second reference speed value. The second reference speed value set in the control device is set to the speed value immediately before the output of the speed signal from the power generation type speed sensor becomes impossible.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a vehicle brake system according to the present invention; FIG. 1 shows a schematic configuration of a vehicle braking device 10 according to an embodiment of the present invention. The master cylinder, the fluid passage, the solenoid valve, the wheel cylinder, and the check valve interposed in the fluid passage that constitute the vehicle braking device 10 of the present embodiment are the same as those of the conventional vehicle braking device shown in FIG. Therefore, the same reference numerals are given to FIG. 1 and the detailed description is omitted.

The vehicle braking device 10 in this embodiment includes a control device 11 for controlling the operation of the solenoid valve 2. The power generation type speed sensor 12 is electrically connected to the control device 11 and constantly detects the speed of the vehicle in response to an output signal from the power generation type speed sensor 12, that is, a speed signal.

The control device 11 detects that the signal from the power generation type speed sensor 12 is shaped as described above when the vehicle is decelerated to a second reference speed value in a low speed range (approximately 4 km per hour). since the signal is not output, it calculates the deceleration ranging from the first reference speed value V ₀ which is set in advance at the time the second reference speed value V ₁ is the low speed range. This deceleration is represented by a speed-time relationship graph as shown in FIG.

That is, in FIG. 2C, the deceleration a from time t ₀ to t ₁ is a = − (V ₁ −V ₀ ) / (t ₁ −
t ₀ ). Vehicles from this deceleration to estimate the likely will the time t ₂ to stop. This estimated stop time is t ₂ = V
It is obtained by the formula of ₁ / a. Thus, the control device 11
When the vehicle enters a deceleration state exceeding the low-speed range, the deceleration from a predetermined speed before the low-speed range to the low-speed range is calculated based on a signal from the power generation type speed sensor 12 to obtain an estimated stop time. Is determined to be stopped, the solenoid valve 2 is actuated, the fluid path 1 is closed, and creep of the vehicle is prevented.

Next, the operation of the vehicle brake system 10 of the present embodiment, particularly the operation of the control device 11, will be described in more detail with reference to the flowchart of FIG. In the control device 11, the vehicle compares the traveling constantly and current vehicle speed V ₁ and previous vehicle speed V ₀ (Step 20)
And, the deceleration is determined that the decelerating when V ₁ is low a
Is calculated (step 21).

Then, in the next step 22, it is determined whether or not a pulse signal has been output. If the pulse signal has been output, the speed of the vehicle is equal to or higher than the low speed range, and the process returns to step 20 again. and the other pulse signal determines that is in the low speed range if it is not output the previous deceleration a from the vehicle stop estimation time t ₁ calculated (step 23),
In order to controls the operation of the electromagnetic valve 2 is judged that if the elapsed by determining whether the vehicle stop estimation time t ₂ at the next step 24 has passed the vehicle is stopped (Step 25) I do.

Thus, when it is attempted to determine the stop state of the vehicle using the power generation type speed sensor, even if the vehicle enters a low speed range and the signal from the power generation type speed sensor is not substantially outputted, the vehicle is reliably detected. Can be confirmed as stopped,
By operating the solenoid valve 2, the fluid path from the master cylinder 7 to each wheel cylinder 3 is closed, and the brake state of the wheels can be maintained despite the depression of the brake pedal.

In the above-described embodiment, the deceleration is calculated from the first reference speed value preset in the control device and the second reference speed value which is a low speed range in which the speed signal from the power generation type speed sensor cannot be output. Was calculated, but the first reference speed value may be detected in real time.

[0024]

As described above, according to the vehicle braking device of the present invention, even when the power generation type speed sensor is used, the stop state of the vehicle is reliably detected, and the solenoid valve interposed in the fluid path is used. By operating the vehicle, it is possible to appropriately prevent creep when the vehicle is stopped. That is, the power generation type speed sensor
Below the weak point, low speed range (approximately 4 km / h)
Use the deceleration to stop the output of the valid signal.
The software solves the problem with a control device that calculates
It is necessary to provide separate hardware components such as
No need for a car to prevent creep
Simultaneously improve the reliability of both braking devices and reduce costs
be able to.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view schematically showing a vehicle braking device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a waveform from a power generation type speed sensor used in the vehicle braking device of the present invention, a pulse signal waveform obtained by shaping the waveform, and a deceleration obtained based on the pulse signal. It is.

FIG. 3 is a flowchart illustrating the operation of the control device that constitutes the vehicle braking device of the present invention.

FIG. 4 is a configuration explanatory view schematically showing a conventional vehicle braking device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid path 2 Solenoid valve 3 Wheel cylinder 7 Master cylinder 8 Brake pedal 9 Check valve 10 Vehicle braking device 11 Control device 12 Power generation type speed sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 7/12 B60T 8/32

Claims (3)

(57) [Scope of request for utility model registration] An electromagnetic valve (2) interposed on a fluid path (1) connecting a master cylinder (7) and a wheel cylinder (3) to control opening and closing of the fluid path (1), and a speed of a vehicle A power generation type speed sensor (12) for detecting a signal, and a control device (11) for receiving a signal from the speed sensor (12) and operating the solenoid valve (2), wherein the control device (11) A vehicle braking device which receives a speed signal from the speed sensor 12, calculates a deceleration, estimates a time until the vehicle stops from the deceleration, and outputs an operation signal to the solenoid valve (2). . 2. The control device (11) calculates a vehicle deceleration from a preset first reference speed value to a second reference speed value, and estimates a time from the deceleration to a vehicle stop. The vehicle braking device according to claim 1, wherein an operation signal is output to the solenoid valve (2). 3. A second control device set in the control device.
The vehicle braking device according to claim 2, wherein the reference speed value is set to a speed value immediately before a speed signal cannot be output from the speed sensor (12).