JPS608143A - Brake force holding system for car - Google Patents

Abstract

PURPOSE:To improve the operational feeling of a brake holding system, by adjusting the waiting time of brake holding in accordance with the stopping state such as abrupt stoppage or stoppage from slow travelling. CONSTITUTION:The waiting time of brake pedal holding is adjusted in accordance with the stopping state of car. Upon stepping of brake pedal, brake switch SW3 will turn on while an accelerator switch SW2 will turn off. Upon dropping of car speed below 10km/h, the output from first car speed detection circuit VDC1 will go H while the output from second car speed detection circuit VDC2 will go L. Consequently, flipflop FF1 will produce H, to turn off transistor Q15 and to turn on transistor Q16 for only predetermined time, thus to turn on transistor Q17 for only such time interval as to be determined by a resistor R11 and capacitor C2. When setting said time interval to be 3sec, Q17 will turn on for 3sec from the time point when the car speed has dropped below 10km/h to apply H onto ont input end of NOR gate NOR1 thus to block brake holding. If the car speed is lower than 2km/h after elapsing said 3sec, brake holding will function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a braking force holding device for a vehicle that maintains a foot brake in a braking state even when the foot is removed from the pedal, and particularly relates to the timing of braking force holding.

A normal foot brake is not suitable for maintaining a braking state for a long time because the braking state is not maintained unless the brake pedal is continuously depressed.

Therefore, a device has been proposed in which a foot brake pedal is held in a braking position when a predetermined condition is met. This main device uses a solenoid or the like to electrically fix the braking position and maintain the braking state, and energizes the solenoid approximately 1.5 seconds after the vehicle has decelerated and stopped. Braking device that holds the foot brake pedal in the braking position (Japanese Patent Laid-Open No. 57-1402)
61). According to this, the braking state can be maintained without continuing to depress the foot brake pedal for a long time. However, with this device, energization of the solenoid is prohibited for approximately 1.5 seconds from the time the vehicle stops, so regardless of the state in which the vehicle is stopped, there is always a waiting time of approximately 1.5 seconds from the time the vehicle stops. was there. In other words, the same waiting time is required when the vehicle suddenly stops and when the vehicle stops while driving slowly.

SUMMARY OF THE INVENTION An object of the present invention is to adjust the waiting time for holding the brake pedal depending on the stopped state of the vehicle, thereby improving the operational feel of a brake holding device for a vehicle.

In order to achieve the above object, in the present invention, holding the brake pedal is prohibited for a predetermined period of time after the vehicle speed becomes equal to or less than a first set vehicle speed, and the prohibition is canceled after the predetermined period of time has elapsed. According to this, when the vehicle suddenly stops, the vehicle speed becomes equal to or less than the first set vehicle speed, and then rapidly comes to a stopped state, and when the vehicle stops, it is within the predetermined time. It is prohibited to hold the brake pedal until this period has elapsed. In addition, when the vehicle stops after driving at a slow speed, etc., the set time will elapse from when the vehicle speed becomes lower than the first set vehicle speed until the vehicle stops. , the brake pedal is held in place a very short time after the vehicle has come to a stop.

In addition, according to the present invention, when the wheels lock during braking due to sudden braking on a low-μ road or due to a hydroplaning phenomenon, holding the brake pedal is prohibited for the predetermined period of time, so that the wheels are locked. This prevents the brake pedal from being held in place, and it is possible to avoid danger during the predetermined time period.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1a shows the vicinity of a foot brake of an automobile equipped with a brake holding device, and FIG. 1b shows a cross section taken along line A--A in FIG. 1a. First, explanation will be given with reference to FIG. 1a. 11
0 is the brake pedal. The brake pedal 110 is
It is supported by a shaft 114 so as to be rotatable within a predetermined range about the shaft. The brake pedal 110 is
A counterclockwise force is applied by a spring (not shown). A shaft 114 is supported by a base plate 113, and the base plate 113 is fixed to a vehicle body 112 with bolts 111.

A long hole 115 is formed in the center of the brake pedal 110, and a rack 11G is formed at the bottom of the long hole 115. A gear 119 is disposed within the elongated hole 115, and the gear 119
is engaged with the rack 116. The gear 119 is secured to a shaft 120, which is connected to a retaining mechanism shown in FIG. 1b.

This will be explained with reference to FIG. 1b. The shaft 120 is inserted into the hub shaft 121 and coupled to each other via a one-way clutch 124. In this example, the shaft 120 and the hub shirts 1 to 121 become entangled in response to a force in the direction of pressing the brake pedal 110 (clockwise in FIG. 1a), but they are coupled in response to a force in the opposite direction. It looks like this.

A plurality of pins 125 are embedded in the hub shaft 121 in a circumferential manner around the shaft 120, and a portion of each pin protrudes from one side of the hub shaft 121 (upper side in FIG. 1b). 122 is a disk-shaped plate, which is rotatable around the shaft 120. A hole is formed in the plate 122 at a position facing the pin 125 of the hub shaft (a position from the center), and the pin 125 is engaged with this hole.

Plate 122 is supported around its periphery by springs 126 and is normally pulled upwardly as shown in FIG. 1b. A yoke 127 around which an electric coil 123 is wound is arranged on the outer periphery of the hub shaft 121 so as to face the plate 122 . Yoke 127 is fixed to base plate 113. 117 is a cover.

Therefore, when the electric coil 123 is not energized, the plate 122 is pulled by the spring 126 and is positioned upward, and the plate 122 and the yoke 127 are separated, so that the integrated play 1-122. Pin 125. Hub shaft 121. One-way clutch 124. Since the shaft 120 and the gear 119 are rotatable, even if the brake pedal 110 is depressed, if the force of depression is released, the brake pedal 110 is returned to its original position by the force of a return spring (not shown) and the brake reaction force, returning to the non-braking state. .

When the electric coil 123 is energized, the plate 122 is pulled toward the yoke 127 by the magnetic attraction force, and the plate h 1
22 and yoke 127 are in close contact, and yoke 127 is fixed to base plate t-113, so play 1-1
22 movement is blocked. Therefore, the gear 119 integrated with the play 1-122 is prevented from rotating. As a result, if the brake pedal 110 is depressed in advance, the brake pedal 110 is held at the braking position, and even if the force with which the brake pedal is depressed is released, the braking state is maintained.

FIG. 2 shows the configuration of an electric circuit that controls the above-described brake holding I configuration. First, if you pay attention to the right end of FIG. 2, there is a solenoid SL. This solenoid SL is the electric coil 123 for holding the brake. A lamp BIL connected in parallel with the solenoid SL is a brake indicator lamp that supports the brake holding state.

Next, pay attention to the left end of FIG. swi is a reed switch that is the first detection means for detecting vehicle speed (opens and closes when the vehicle moves), SW2 is an accelerator switch for detecting idling state (opens when the accelerator is off), and SW3 is a foot brake pedal 110 SW4 is the brake switch that detects the position of the brake switch (closed when braking), and SW4 is the ignition switch (closed when turned on). Further, a stop lamp SPL indicating the braking state of the vehicle is connected to SW3.

The circuit REG connected to the output side of the ignition switch SW2 is a stable power supply circuit that generates a stable power supply voltage to be supplied to an integrated circuit (gate circuit), etc.

In addition, three types of vehicle speed detection circuits VDCI, VDC2, VDC
3. Equipped with a delay circuit DEL, etc.

In this example, the first vehicle speed detection circuit VDC1 detects a vehicle speed of 1 or 5.
km/h (second setting value) or less, the output level becomes L, and if the vehicle speed is less than 15 km/h or lQkm/h
If it is higher than h, the output level becomes II. The second vehicle speed detection circuit VDC2 has an output level of H when the vehicle speed is 10 km/kt (first set value) or more, and an output level of L when the vehicle speed is less than 10 km/kt (first set value).

Third vehicle speed detection circuit VDC3, vehicle speed 2km/h
If the vehicle speed is higher than that, the output level becomes H, and if the vehicle speed is at or below the vehicle speed, the output level becomes L. Also, delay gate II D
EL generates the timing for brake hold.

Nantes Gate NAI, NA2 and Nantes Gate NA3
．． NA4, RS flip-flop FF1. F
It constitutes F2.

The operation of the brake holding device and parking brake drive device according to each state of the vehicle (switches) will be explained in detail below. and the relationship between signal level and device operation.

Below is the margin 1st table However, Operation ■: Brake Bedanoi 19. BIL lighting lever■:
Next, each operation will be explained in detail.

(1) Brake pedal holding operation The conditions for performing the brake pedal holding operation are as shown in ■ in Table 3, when the vehicle detects a stop state S<that is, VDC3 detects a vehicle speed of 2 km/h or less; (see table), when the accelerator is off and the foot brake is depressed. Therefore, accelerator switch SW2
is opened, the transistor Q5 is turned off, the transistor Q6 is turned off, the collector potential of the L-range disk Q6 becomes H, and the Nant gate NA of the flip-flop FF2 is turned off.
11 is applied to the input terminal of 4. At this time, the vehicle speed is 2km
/ h or less, the output of the third vehicle speed detection circuit VDC3, that is, the transistor Q13 is turned on, thereby applying L to the NAND gate I- of the flip-flop FF2. Here, the flip-flop FF2 constitutes a negative logic R3-flip-flop, with the input terminal of the NAND gate NA3 serving as the input terminal to the cell 1, and the input terminal of the NAND gate NA4 serving as the reset input terminal. therefore,
The output of the flip-flop 0FF2 becomes L, which is applied to one input terminal of the NOR gate N0RI. At this time, the delay circuit DE is connected to the other input terminal of NORI (NORI).
When L to L is applied (this condition will be described later), H is output to the output terminal of the NOR gate NoR1. These 11 outputs are inverted by NOR gate 1-N0R2 and input to one terminal of NOR gate NOR3.

Here, when the brake switch SW3 detects braking and is closed, the transistor Q1 is turned on, and the transistor Q7. Since both transistors Q8 are turned on, the collector potential of the transistor Q8 becomes .
It is input to the other terminal of OR3. Therefore, the output of NOR3 becomes H, which causes transistor Q1
8 is applied to the base of solenoid SL, turning on transistor Q1B and turning on transistor Q19.
and energizes the brake hold indicator lamp BIL.

In other words, the plate 122 in FIG. 1b contacts the yoke 127 and is prevented from rotating, so the foot brake pedal 110 is held at the depressed position and the braking state is maintained.

Here, the delay circuit DEL sends the L output to the NOR gate N0RI.
The conditions for applying the voltage to the other terminal of the voltage will be explained based on Table 2 and FIG. The reed switch SW1 generates a pulse according to the rotation of the wheel, and the faster the vehicle speed, the shorter the pulse (the higher the frequency) is output. This pulse turns transistors Q3 and Q4 on and off, and correspondingly transistor Q also turns on and off, and this signal is transmitted to each vehicle speed detection circuit VDCI, VDC2, VDC3.
is applied to Here, each vehicle speed detection circuit VDCL VD
C2, VDC3 transistor Q11゜QIO, Q13
- Each vehicle speed is 15 km/h.

10 km/h, resistors R2, R3, R4, R5, R6 to turn on when the speed drops below 2 km/h.
, R7, R8, and R9 are fixed. However, since the signals applied to each transistor Qll, QIO, and Q13 are pulses, they are repeatedly turned on and off in response to these pulses when the vehicle speed drops below a predetermined value. Also, the first
The vehicle speed detection circuit VDC1 has a transistor Q12.
The signal of transistor Qll is inverted and output.

The brake holding circuit is controlled as follows by the vehicle speed detection circuit set as described above. Here, the flip-flop FFI is a positive logic R3-flip-flop having the input terminal of the Nant gate NAI as a set input terminal and the input terminal of the Nant gate NΔ2 as a reset input terminal.

First, if the vehicle speed is greater than 15 km/h, the dog 1 vehicle speed detection circuit VDCI detects this and
Since the L output is applied to the flip-flop FFI, the flip-flop FFI is reset and its output becomes the L output. Therefore, since the transistor Q14 is turned on, the transistor Q15 of the delay circuit DEL is turned on, and the transistor Q16 is turned off.
Transistor Q17 is off.

Next, when the vehicle speed becomes 10 km/h or less, the output of the first vehicle speed detection circuit VDCI becomes H2 first as shown in Table 2.
The output of the vehicle speed detection path VDC2 becomes L. Therefore, the flip-flop FF14 is set and outputs H.

Therefore, the 1-range disk Q14 is turned off, and the transistor Q15 is turned off.

Therefore, since the collector potential of transistor Q15 becomes ti, transistor Q16 is turned on only for a predetermined time determined by resistor R10 and capacitor C1. Therefore, transistor Q17 is also turned on, but the on-time period is determined by resistor R11 and capacitor C2, and is suitably several seconds. Here, this on time is 2~
It is set to 3 seconds. In other words, since the I transistor Q17 is turned on for 2 seconds from the time when the vehicle speed becomes less than 1Q km/h, 2 is applied to one input α111 of the NOR game 1-N0R1. Even if FF2 applies ① to the other input terminal of NOR gate N0R1, brake holding does not operate.

As mentioned above, the delay circuit DEL determines whether the vehicle speed is IQ km
/ h or less, it is prohibited to hold the brake for 3 seconds. Therefore, 3 seconds after the vehicle speed drops below 10+n/h, the vehicle stops (vehicle speed drops to 2+n/h).
km/h), brake hold is activated immediately. In addition, if the vehicle suddenly locks due to a low μ road, etc., brake holding is prohibited for 3 seconds, so that erroneous brake holding can be prevented by locking the wheels.

(2) Brake pedal release operation The condition in this case is when the accelerator is depressed, as shown in (■) in Table 3. Therefore, since accelerator switch SW2 is closed, transistor Q5 is turned on,
The transistor Q6 is turned on and the input terminal of the Nant gate NA4 of the flip-flop FF2 becomes L. This L signal resets the flip-flop FF2, inverts its output, and outputs an H signal. This ■1 output is Noah 1
- Since it is applied to one input terminal of N0RI, the output of NOR gate N0RI becomes L, which causes NOR gate N0
The 14 outputs are inverted by R2 and applied to the NOR gate NOR3. Therefore, Noah game 1-N.

R3 is inverted and the output becomes L, and the l transistor Q18
is turned off, and transistor Q28 is turned off.

Therefore, the solenoid SL is deenergized and the brake holding is released.

Since a return spring (not shown) is connected to the brake pedal 110, the brake pedal 110 automatically returns to its original position when the brake holding (solenoid SLO energization) is released.

In the example, the electric circuit is constructed using a large number of transistors, gate circuits, etc., but a microcomputer that operates so as to obtain the output level according to the state of each switch in the same manner as in the example is used. The present invention can also be carried out using the following methods.

[Brief explanation of the drawing]

Figure 1a is a side view showing the vicinity of the foot brake pedal of a vehicle equipped with a brake holding mechanism, and Figure 1b is A of Figure 3.
-A sectional view. FIG. 2 is a circuit diagram showing the electric circuit of the embodiment. 110...Brake pedal, 113...Base play 1, 122...Plate, 123 (SL)・
...Electric coil, 124...One-way clutch, 1
26...Spring, 127...Yoke, SWl・
・・Reed switch (first detection means), SW2・・
・Brake switch (second detection means), SW3...
Accelerator switch, SW4...Ignition switch, VDl, VD2. VD3...Vehicle speed detection circuit, D
IE L...delay circuit, BIL...brake holding indicator lamp Patent applicant Aisin Seiki Co., Ltd. Representative Reio Nakai Figure 1a Figure 1b

Claims (2)

[Claims] (1) Brake holding means for holding the operation of the brake mechanism; first detection means for detecting vehicle speed; second detection means for detecting the braking operation of the foot brake; electronic control means that prohibits energization of the brake holding means for a predetermined period of time when the value becomes smaller than a set value, and energizes the brake holding means according to the output signal of the second detection means after the elapse of the predetermined period of time; A vehicle brake holding device comprising: (2) The electronic control means releases the prohibition of energization of the brake holding means when the output signal of the first detection means becomes larger than a second set value that is set higher than the first set value. A braking force holding device for a vehicle according to claim (1)