JPH0268254A - Braking state display unit in snow-covered road and braking controller - Google Patents

Abstract

PURPOSE:To make a braking state easily recognizable by assortively displaying respective areas: 1. Leg power will not function as braking force, 2. braking torque increases in proportion to this leg power value, 3. the braking torque comes almost constant even if this leg power value is increased, and 4. the braking torque decreases in inverse proportion to the leg power value. CONSTITUTION:A lamp 10a is achromatically lighted at time of a stroke value of 0%, a lamp 10b is blue at time of the stroke value of 10%, lamps 10c-10h are yellow at time of the stroke value of 10-70%, and these lamps are displayed in red at time of the stroke value of 70-100% as being set in advance respectively by floating adjustment through each of set buttons. Then, at the time of braking of driving on a snow-covered road, if a brake pedal 3 is operated, the stroke displacement is converted into an electric signal via a detecting means 2, whereby a display body 1 judges the stroke value and the braking torque value, lighting the concerned lamp of the braking state display lamps 10a, and a braking state is informed. When a braking state display lamp 10i is lighted, a warning sound is generated from a speaker 14 because of entering into a hazardout area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a braking state display device for a vehicle running on a snowy road or other road surface where the maximum coefficient of friction between the road surface and the tires is small.
In particular, the present invention relates to a braking control device using a braking state display device and an anti-lock braking device for use on snowy roads, etc., so that the vehicle can be effectively braked without the tires becoming locked.

``Prior Art'' It has been known that the braking force in the vehicle shown in FIG. Since TfW is determined in advance as a constant at the time of operation, it is understood that as a result, the braking force B changes proportionally based on the braking torque T or the friction coefficient.

B= (T/R)= (Le W) ・・・・・・■B:
Braking force, T: Braking torque, R: Effective radius of the tire, T: Friction coefficient between the tire and the road surface, W: Load applied to the wheel.On the other hand, the friction coefficient between the tire and the road surface on a snowy road is shown in Figure 5. As shown, the value is less than half that of a wet paved road, and less than I/4 for a dry concrete road. Therefore, the braking force of a vehicle is significantly reduced on snowy roads. , said f! Even if a hydraulic pressure greater than the limit braking force (torque) corresponding to the friction coefficient is applied, the remaining braking hydraulic pressure that exceeds the braking force simply acts as a force to lock the tire, and due to the lock, This may lead to tire slippage or a decrease in braking force, and in the worst case, the vehicle may turn irregularly and become unable to be steered.

For this reason, the braking method on snowy roads is to use a pumping braking method, which intermittently repeats this process while loosening the braking force before the tires become locked, in order to maintain the hydraulic pressure within the above-mentioned limit braking force range. However, as mentioned above, on snowy roads, the coefficient of friction with the road surface is extremely low, so it is extremely difficult to loosen the braking force before it becomes locked, and the limit braking force is reached. With conventional vehicle braking systems, it is only possible to know whether a tire has slipped or not after the tire slips. Therefore, the above-mentioned braking system has to rely on the driver's skill, and is difficult to use on snowy roads. It is very dangerous for those who are inexperienced in driving to continue applying braking force even after relocking when the tires have slipped considerably.

However, even if the driver is an experienced driver, the braking force changes depending on the radius R of the tire and the load W applied to the wheel. (hydraulic pressure) changes, making it difficult to adjust.

Therefore, in order to increase the above-mentioned limit braking force level, spiked tires and studless tires have been developed that improve the coefficient of friction between the tire and the road surface on snowy roads, and the brake system of the vehicle also prevents the wheels from locking. The so-called anti-lock brake system, which automatically relieves the brake fluid pressure before entering the
(hereinafter referred to as ABS) has been developed, and the ABS
The system is equipped with a judgment circuit such as a microcomputer as a control means, and the judgment circuit determines whether the wheels are in a locked state or not based on the actual wheel deceleration and braking during normal road running to ensure that the wheels do not lock. It is configured to make a judgment based on a comparison with a reference wheel deceleration, and based on the judgment result, open and close the on-off valve of the brake hydraulic valve to loosen the brake hydraulic pressure and prevent the wheels from locking up. .

``Problem to be Solved by the Invention'' However, setting a standard wheel deceleration that does not cause wheel locking in the ABS is difficult because, as mentioned above, the coefficient of friction with the road surface differs significantly depending on the road surface condition. This cannot be stipulated by law; for example, JP-A-80-255
No. 55f3 proposes an ABS characterized in that the reference value is set within the range of wheel deceleration that occurs during braking under normal road running conditions, but in this technology, the reference value cannot be set accurately. This is extremely difficult to control, especially on snowy roads, where the signal to loosen the brake hydraulic pressure is not output from the judgment circuit even though the wheels are locked, and the judgment circuit for opening and closing the hydraulic pulp. It is also difficult to accurately measure the actual vehicle deceleration that should be used for judgment, and accurate control cannot necessarily be performed.

In view of the prior art, the present invention is configured such that the limit braking force area of the vehicle can be visually and easily grasped, so that the driver can easily recognize the braking state when braking and the tires are in a locked state. To provide a braking control device using a braking state display device and an anti-low two-wheel braking device on snowy roads etc., which can effectively brake a vehicle without causing the problem.

"Means to solve problems" First, the process leading to the present invention will be explained based on FIG.

In Figure 4, the vertical axis shows the braking torque value or the braking acceleration value corresponding to the braking force, and the horizontal axis shows the brake pedal stroke value (
(upper row) and slip ratio (%) were taken. It is a graph of the braking performance of studless tires and spiked tires on snowy roads in ice burn conditions. In other words, as can be understood from Fig. 4, after the braking starts after passing through the play area of the brake (this point is defined as the stroke amount θ%), the braking torque value that continues to increase in proportion to the brake stroke amount is After reaching the tire's initial saturated braking torque value (point A) at a stroke amount of 10 to 4 oz, the braking torque value remained almost unchanged even when the stroke amount was increased, and showed a value close to the maximum braking torque. As a result, the slip ratio only increases, and the braking force energy is consumed in the form of tire slip. If the stroke amount continues to increase further, the braking torque value begins to decrease when the stroke amount is around 70 to 30 (hereinafter referred to as the final saturation torque value, point B), resulting in severe slippage and side skidding when the tires are locked. and reaches the dangerous range.

Although this tendency differs depending on the type of tire, it is understood that all tires have a part where the tire remains locked or slips on snowy roads until the brake pedal reaches its maximum stroke value. be done.

However, the danger zone exceeding point B is more common with studless tires, which have been widely used in recent years, and the probability of accidents increases accordingly.

Therefore, the present invention provides a detection means for detecting the stroke amount, and based on the signal from the detection means, one area is set from the play part of the brake to the braking start point (P), and the initial saturated braking is performed from the braking start point. For each region, the area from the initial saturated braking torque value to the final saturated torque value (A-B) is the ■ area, the area from the initial saturated braking torque value to the final saturated torque value (A-B), and the area after the final saturated torque value (B ~). For example, the color segments are characterized by being visually distinguished using display lamps or the like.

In this case, it is preferable to visually express the classification of each area by using a color display, but if there is a means that can appropriately communicate to the driver, the braking force value can be displayed numerically, or an analog display with one character can be used. The notification may be made by display or voice.

In addition, since the stroke amount has a proportional relationship with the depressing force applied to the brake pedal, the depressing force may be configured to be detectable using a load cell or the like, or the braking oil pressure itself may be configured to be detectable. It's okay.

Further, the detection signal may be used as a detection signal for the ABS itself.

"Function" According to such technical means, for example, an indicator lamp corresponding to the area where the stroke of the brake pedal does not act as a braking force is displayed in a colorless area, and an indicator lamp corresponding to the area where the braking torque increases in proportion to the stroke amount. is displayed in green, the indicator lamp corresponding to the area where the braking torque remains almost constant even if the stroke amount increases is displayed in yellow, and the indicator lamp corresponding to the area where the braking torque decreases in inverse proportion to the stroke amount is displayed in red. By providing a group of display lamps to display and configuring one of the lamps to be displayed based on the detection signal that detects the brake stroke, it is possible to detect when the current amount of depression of the brake pedal exceeds the limit braking force area of the vehicle. It is easy to visually and easily determine whether or not the vehicle has exceeded the limit (green lamp or yellow lamp), and even if it has exceeded it, whether it has reached the area where skidding is likely to occur (yellow lamp or rare lamp). This allows the driver to easily recognize the braking state during braking and effectively brake the vehicle without the tires locking up.

Therefore, with this device, when driving on a snowy road, it is possible to accurately know the braking state when driving on a snowy road, which previously relied only on the driver's feeling, so that the desired braking operation can be performed accurately and reliably without any error in the driver's feeling. can be obtained. In other words, by recognizing the display, the driver can judge whether the driver's current application of braking force is appropriate or not, and the driver himself/herself can adjust the braking force to prevent the tires from locking up. Naru 1J
G can be prevented.

It is also possible to set the braking state display device in conjunction with a braking device so that when the braking state display device is activated on a snowy road, no braking force is applied to the braking device until the tires become locked. For example, in ABS, the detection output from a detection means that detects a numerical value proportional to the depression of the brake pedal is input to the ABS, and the AB
It is also possible to use S to maintain the braking oil pressure of the vehicle within a range in which the braking torque increases in proportion to the amount of depression of the brake pedal.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. It's nothing more than that.

FIG. 1 shows a braking state display device according to a first embodiment of the present invention, where l is the display device body, 2 is a detection means for detecting the stroke amount of the brake pedal 3, and its detection output is transmitted along with the display device body l. It is configured so that it can be used as a detection input for the control circuit 61 of.

The state display device main body 1 has a group of display lamps 10a, .

Button group 13a..., speaker 14, power switch I
f and a power lamp 12, and is configured to be able to light up one indicator lamp selected from the group of indicator lamps based on a detection signal from a detection means 2 for detecting a brake stroke.

That is, the indicator lamp group 10a... is configured to be able to selectively light up in 10% increments corresponding to the amount of brake stroke, and the braking state set button 13
By the floating adjustment by a..., the position of the color of the display lamp group 10a... is adjusted according to the type of each tire.

For example, in a studless tire, the braking starting point (
P) is 0%, initial saturated braking torque value (A) is 10%
, final saturation torque value CB); 6 < 70% (7) Because of the floating adjustment using each set button 13a..., the lamp loa lights up colorless when the stroke amount is 0%, and the stroke amount ~ 10%. %, lamp 10b turns blue, stroke [10 to 70%, lamp 10c ~]
Set the display lamp so that it turns yellow at Oh and red when the stroke amount is 70-100%.However, the indicator lamp can be set when changing the tire, or by incorporating a storage device into the display unit l and setting it in several types. If you memorize the braking conditions of the tires, you can easily operate the lamp set.

According to this embodiment, before starting driving on a snowy road, the power switch 11 is turned on and the display device main body 1 is activated. During braking, when the brake pedal 3 is depressed, the stroke displacement is converted into an electrical signal via the detection means 2 and input to the detection device signal input terminal 18 of the display device main body l, and then The braking force value of the brake pedal 3 is determined from the electrical signal input from the brake pedal 3, and the stroke amount and braking torque value are determined from the relationship between braking torque and stroke wear of the studless tire shown in FIG.
The braking state display lamp 10a... is turned on to notify the driver of the current braking state.

Further, when the braking state display lamp 10i lights up, it means that the vehicle has entered the danger zone (3), and a warning sound is generated from the speaker 14 to give the driver more caution.

In this embodiment, an example was shown in which the braking status is displayed to the driver by lighting a series of lamps, but if there is a means that can properly communicate the braking force value to the driver, it may be possible to display the braking force value numerically or by analog. The notification may be made by display, text, or voice.

The detection output is input to the ABS control circuit 61 and the brake oil pressure from the brake pedal 3 is input to the oil pressure control circuit 62, and based on these signals, the ABS is used to adjust the brake oil pressure of the vehicle to the brake pedal. It is also possible to configure the braking torque to be maintained within a range in which the braking torque increases in proportion to the amount of depression.

FIG. 2 is a schematic diagram when the hydraulic pressure of the hydraulic cylinder of the brake pedal 3 is detected and is activated.

During braking, the hydraulic pressure transmitted to the mask cylinder 20 by depressing the brake pedal 3 is transmitted as hydraulic pressure to the tire braking device, so the hydraulic pressure is detected by the hydraulic pressure detection device 12A, and the hydraulic pressure is transmitted to the tire braking device. It is configured to convert the hydraulic pressure value into an electrical signal and input it to the detection device signal input terminal 16 of the braking state display device main body l.

FIG. 3 shows a brake pedal 3 with a pedal force detection device attached thereto and an enlarged view of the pedal, and shows a case where a load cell or the like is attached to the surface of the brake pedal 3 as a pedal force detection device 2B, and the load displacement of the pedal force of the driver 5 is shown. is detected by a load cell, and the braking state is displayed by a braking state display device (not shown).

"Effects of the Invention" As described above, according to the present invention, the limit braking force area of the vehicle is configured to be visually and easily graspable, and thereby the driver can easily recognize the braking state when braking. This has made it possible for the city to provide a braking control device that utilizes a braking status display device and anti-lock braking device for use on snowy roads, etc., which can effectively brake a vehicle without causing the tires to lock up, and has put it into practical use. The value is extremely great.

In recent years, pollution problems have arisen when vehicles are running with spiked tires, and there is a trend toward banning the use of spiked tires, and there is a trend toward using studless tires.As shown in Figure 4, studless tires are When driving on snowy roads, the brake torque reaches the m range where the braking torque remains almost constant even if the brake pedal pressure increases, and the ■ region where the braking torque decreases in inverse proportion to the brake pedal pressure, even if the brake pedal pressure is lower than that of the tires. However, the present invention makes it possible to eliminate such drawbacks and makes it possible for the driver to easily recognize the braking state during braking, which is extremely practical.

It has various effects such as

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a braking state display device and an anti-lock braking device for use on snowy roads, etc., according to an embodiment of the present invention, and a brake pedal stroke amount detecting device is used as the detecting means. FIG. 2 is a schematic view showing an embodiment in which oil pressure from a hydraulic cylinder of a brake pedal is used as a detection means, and FIG. 3 is an enlarged view of a brake pedal and a pedal equipped with a pedal force detection device in another embodiment. In Figure 4, the vertical axis shows the braking torque value or the braking acceleration value corresponding to the braking force, and the horizontal axis shows the brake pedal stroke value (
It is a graph showing the braking performance of studless tires and spiked tires on snowy roads in ice burn conditions, taking the slip ratio (%) and slip ratio (%). FIG. 5 is a graph showing the relationship between the coefficient of friction between the tire and the road surface and the slip ratio, and FIG. 6 is a diagram showing the effect of the force acting on the vehicle during braking. ＼Anana 7-Special old ε斐萱廿都

Claims (1)

[Scope of Claims] 1) In a braking state display device for a vehicle traveling on a snowy road or other road surface where the maximum coefficient of friction between the road surface and the tires is small, an area where the stroke corresponding to the amount of depression of the brake pedal does not act as a braking force; A display group that divides and displays areas where the braking torque increases in proportion to the stroke amount, areas where the braking torque remains almost constant even when the stroke amount increases, and areas where the braking torque decreases in inverse proportion to the stroke amount. A braking state display device 2 characterized in that a detection means for detecting the brake stroke is provided, and one display section selected from the display group can be displayed based on a detection signal from the detection means. ) In braking status display devices for vehicles running on snowy roads or other roads where the maximum coefficient of friction between the tires and the road surface is small, the area where the pedal effort that changes in response to the amount of depression of the brake pedal does not act as braking force, and the amount of depression force A display group that separately displays an area where braking torque increases proportionally, an area where braking torque remains almost constant even when the amount of pedal effort increases, and an area where braking torque decreases in inverse proportion to the amount of pedal effort, and the brake. 3) A braking state display device comprising a detection means for detecting the pedal force of the brake pedal, and a display section selected from the display group can be displayed based on a detection signal from the detection means. In braking status display devices for vehicles running on roads and other roads where the maximum coefficient of friction between the tires and the road surface is small, the area where the braking oil pressure, which changes based on the amount of brake pedal depression, does not act as a braking force, is proportional to the braking oil pressure. a display group that divides and displays an area where the braking torque increases, an area where the braking torque remains almost constant even when the braking oil pressure is increased, and an area where the braking torque decreases in inverse proportion to the braking oil pressure; A braking state display device comprising: a detection means for detecting braking oil pressure of a brake; and one display section selected from the display group can be displayed based on a detection signal from the detection means. . 4) The detection output from the detection means that detects a numerical value proportional to the amount of depression of the brake pedal is input to the anti-lock braking device, and the anti-lock braking device is used to adjust the braking oil pressure of the vehicle to the brake pedal. A braking control device configured to maintain braking torque within a range in which braking torque increases in proportion to the amount of depression.