JPH0446785B2 - - Google Patents

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. With normal foot brakes, the braking state is not maintained unless the brake pedal is continuously depressed.
It is not suitable for maintaining a braking state for a long time. 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. There is a braking device (Japanese Unexamined Patent Publication No. 140261/1983) that holds the foot brake pedal in the braking position. Furthermore, Japanese Utility Model Application Publication No. 53-27527 discloses a technology that maintains the braking state even if the brake pedal is released when the brake pedal is depressed after a predetermined time set by a timer after zero vehicle speed is detected. ing. According to this, the braking state can be maintained even if the foot brake is released after a predetermined time has elapsed after the vehicle has stopped, without having to keep pressing the foot brake pedal for a long time. However, the brake holding operation is not activated unless the foot brake is continuously depressed for a predetermined period of time after the vehicle has stopped. Therefore, if the driver takes his foot off the brake pedal immediately after thinking that the vehicle has stopped, there is a risk that the vehicle will start moving. However, in conventional technology, if the predetermined time is shortened, even if the wheels lock due to sudden braking, there is a risk that the vehicle will mistakenly assume that the vehicle speed is zero and retain the braking force with the wheels locked. , the predetermined time could not be shortened. Therefore, in the present invention, holding the braking force when the wheels are locked during sudden braking is prohibited, and
The purpose is to maintain braking force almost simultaneously with the vehicle stopping during gentle braking. In order to achieve the above object, the means taken in the present invention include: a first vehicle speed determining means for determining from the output of the vehicle speed detecting means that the vehicle speed is below a predetermined first set vehicle speed; a second vehicle speed determination means for determining from the output that the vehicle is stopped; a delay means for delaying the output by a predetermined time after the first vehicle speed determination means detects a vehicle speed below a predetermined speed; and during the delay by the delay means. and driving means for inhibiting the holding operation of the brake mechanism and operating the brake holding means to hold the brake mechanism after the delay by the delay means and when the second vehicle speed determining means determines that the vehicle has stopped. That's true. According to the above means, when the vehicle is running at a speed equal to or higher than the first set vehicle speed, when the vehicle is braked by a brake operation and the vehicle speed decreases, the delay means delays the vehicle when the vehicle speed drops below the first set vehicle speed. Start. At this time, the holding operation of the brake mechanism is prohibited by the driving means. When the vehicle stops after the delay by the delay means is completed, the second vehicle speed determination means determines that the vehicle has stopped, and the drive means operates the brake holding means to hold the brake mechanism. When the vehicle is braked slowly, the vehicle speed is
It takes a considerable amount of time for the vehicle to reach the set speed and stop. During this time, the delay means has completed its delay, so in the case of slow braking, the brake mechanism is held almost at the same time as the vehicle stops. Further, when the vehicle is suddenly braked, the brake mechanism is prohibited from being held during the delay time by the delay means after the vehicle speed falls below the first set vehicle speed. Therefore, even if the wheels are momentarily locked due to sudden braking and the vehicle speed is zero, the brake mechanism will not perform a dangerous holding operation to maintain the locked state. In the present invention, even if the wheels lock instantaneously due to sudden braking, the brake mechanism does not hold the vehicle, so it is safe. Furthermore, in the case of slow braking, the holding operation of the brake mechanism can be performed at the same time as the vehicle is stopped. Therefore, unlike conventional devices, it is not necessary to continue pressing the brake for a while after the vehicle stops until the brake mechanism is held in place. Therefore, there is no need to worry about the vehicle starting to move even if you take your foot off the brake pedal immediately after thinking that the vehicle has stopped. Embodiments of the present invention will be described below with reference to the drawings. Fig. 1a shows the vicinity of the foot brake of an automobile equipped with brake holding means, and Fig. 1b shows the vicinity of the foot brake of an automobile equipped with brake holding means.
A cross section taken along line A-A in figure a is shown. First, explanation will be given with reference to FIG. 1a. 110 is a brake pedal. The brake pedal 110 is supported by a shaft 114 so as to be rotatable within a predetermined range about the shaft 114. The brake pedal 110 is constantly subjected to counterclockwise force by a spring (not shown). The shaft 114 is the base plate 113
A base plate 113 is fixed to the vehicle body 112 with bolts 111. There is a long hole 115 in the center of the brake pedal 110.
is formed, and a rack 11 is formed at the bottom of the elongated hole 115.
6 is formed. A gear 119 is disposed within the elongated hole 115 and meshes with the rack 116. The gear 119 is fixed to a shaft 120, which is connected to brake retaining means shown in FIG. 1b. This will be explained with reference to FIG. 1b. Shaft 120
are inserted into the hubshaft 121 and coupled to each other via a one-way clutch 124. In this example, the brake pedal 11
The shaft 120 and the hub shaft 121 become entangled in response to a force in the direction of pushing in the 0 (clockwise direction in FIG. 1a), but they are coupled in response to a force in the opposite direction. 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 to one side of the hub shaft 121 (upper side in FIG. 1b). 122
is a disk-shaped plate, and is rotatable around the shaft 120. plate 12
2 has a hole formed at a position facing the pin 125 of the hubshaft (position from the center), and the pin 125 is engaged with this hole. The plate 112 has its periphery connected to the spring 1.
26 and is normally pulled upwardly as shown in Figure 1b. A yoke 127 around which an electric coil 123 serving as a driving means 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,
Plate 122 is pulled upward by spring 126, and plate 122 and yoke 127 are separated, so that plate 122, pin 125, hub shaft 121, one-way clutch 124, shaft 120, and gear 119 are integrated.
is rotatable, so the brake pedal 110
Even if the brake pedal 110 is depressed, if the force of depression is released, the brake pedal 110 returns to its non-braking state due to the force of a return spring (not shown) and the brake reaction force. When the electric coil 123 is energized, the plate 122 is pulled toward the yoke 127 by magnetic attraction, and the plate 122 and the yoke 127 are brought into close contact with each other.Since the yoke 127 is fixed to the base plate 113, the movement of the plate 122 is prevented. is prevented. Therefore, the gear 119 integrated with the plate 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 electronic control means for controlling the above-mentioned brake holding means. First, if you look at the right end of Figure 2, there is a solenoid SL.
This solenoid SL is the electric coil 123 for holding the brake. The 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 Figure 3. SW1 is a reed switch (opens and closes when the vehicle moves), which is a vehicle speed detection means for detecting vehicle speed, SW2 is an accelerator switch (opens when the accelerator is off) for detecting the idling state, and SW3 is the position of the foot brake pedal 110. The brake switch (closed when the braking position is applied) is the brake detection means for detecting the brake, 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 integrated circuits (gate circuits), etc. In addition, three types of vehicle speed detection circuits VDC1, VDC2,
Equipped with VDC3, delay circuit DEL, etc. 1st
In this example, the vehicle speed detection circuit VDC1 detects that the vehicle speed is 15.
If the vehicle speed is Km/h (second set value) or more, the output level becomes L, and if the vehicle speed is less than 15 Km/h and 10 Km/h or more, the output level becomes H. Second vehicle speed detection circuit
The output level of VDC2 is H when the vehicle speed is 10 km/h (first set value) or more, and the output level is L when the vehicle speed is less than that. The output level of the third vehicle speed detection circuit VDC3 is H when the vehicle speed is 2 km/h or more, and the output level is L when the vehicle speed is less than 2 km/h. Further, a delay circuit DEL, which is a delay means, generates timing related to brake holding. NAND gates NA1, NA2 and NAND gates NA3, NA4 constitute RS flip-flops FF1, FF2, respectively. The first vehicle speed detection circuit VDC1, the second vehicle speed detection circuit VDC2, and the flip-flop FF1 indicate that the vehicle speed is the first set vehicle speed10.
It constitutes a first vehicle speed determination means that determines whether the vehicle speed has fallen below Km/h. In addition, the third vehicle speed detection circuit
The VDC 3 constitutes second vehicle speed determining means for determining whether the vehicle has stopped. Below, we will explain in detail the operation of the brake holding device and parking brake drive device according to each state of the vehicle (switch).
Tables 2 and 3 show the relationship between switch operation and signal level, and the relationship between signal level and device operation.

【table】

【table】

[Table] However, Operation: Brake pedal held, BIL lit Operation: Brake pedal released Next, each operation will be explained in detail. (1) Brake pedal holding operation The conditions for brake pedal holding operation are as follows.
As shown in Table 3, when the vehicle is stopped (that is, when VDC3 detects a vehicle speed of 2 km/h or less; see Table 2), this is the case when the accelerator is off and the foot brake is depressed. Therefore, the accelerator switch SW2 is opened, the transistor Q5 is turned off, the transistor Q6 is turned off, the collector potential of the transistor Q6 becomes H, and the NAND gate NA of the flip-flop FF2 is turned off.
H is applied to the input terminal of 4. At this time, the vehicle speed is 2
If it is less than Km/h, the third vehicle speed detection circuit VDC3
By turning on the output of transistor Q13, L is applied to the NAND gate of flip-flop FF2. Here, flipflop
FF2 constitutes a negative logic RS-flip-flop, with the input terminal of NAND gate NA3 serving as a set input terminal, and the input terminal of NAND gate NA4 serving as a reset input terminal. Therefore, the output of flip-flop FF2 becomes L, which is the NOR gate.
Applied to one input end of NOR1. At this time,
A delay circuit is connected to the other input terminal of the NOR gate NOR1.
When L is applied from DEL (this condition will be described later), H is output to the output terminal of the NOR gate NOR1. This H output is the Noah gate
It is inverted by NOR2 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 transistors Q7 and Q8 are both turned on, so the collector potential of the transistor Q8 becomes L, which causes the NOR gate NOR3 to turn on. input to the other terminal. Therefore, the output of the NOR gate NOR3 becomes H, which is applied to the base of the transistor Q18, turning on the transistor Q18.
Since transistor Q19 turns on, the solenoid
Energize SL and brake hold indicator lamp BIL. In other words, the plate 122 shown in FIG. 1b comes into contact with 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 converts the L output into a NOR gate.
The conditions to be applied to the other terminal of NOR1 will be explained based on Table 2 and FIG. reed switch
SW1 generates a pulse according to the rotation of the wheel, and the faster the vehicle speed, the shorter the pulse width (higher frequency) is output. This pulse causes
Transistors Q3 and Q4 are turned on and off, and accordingly, transistor Q is also turned on and off, and this signal is applied to each vehicle speed detection circuit VDC1, VDC2, and VDC3. Here, each vehicle speed detection circuit VDC1,
VDC2, VDC3 transistors Q11, Q1
0 and Q13 have vehicle speeds of 15km/h and 10km/h, respectively.
Resistors R2, R3, R4, R5, R6, R7, R8,
R9 has been decided. However, each transistor Q1
Since the signals applied to Q1, Q10, and Q13 are pulses, they are repeatedly turned on and off in response to these pulses when the vehicle speed falls below a predetermined value. Furthermore, the first vehicle speed detection circuit VDC1 inverts the signal of the transistor Q11 using the transistor Q12 and outputs the inverted signal. The brake holding circuit is controlled as follows by the vehicle speed detection circuit set as described above. here,
Flip-flop FF1 is NAND gate NA1
The input terminal of is the set input terminal, and the NAND gate NA
Positive logic RS- with the input terminal of 2 as the reset input terminal
It is a flip-flop. First, when the vehicle speed is greater than 15 km/h, the high 1 vehicle speed detection circuit VDC1 detects this and applies an L output to the NAND gate NA2, so the flip-flop FF1 is reset and its output becomes an L output. Therefore, the transistor Q14 is turned on, so the transistor Q15 of the delay circuit DEL is turned on, the transistor Q16 is turned off, and the transistor Q
17 is off. Next, when the vehicle speed becomes 10 km/h or less, the output of the first vehicle speed detection circuit VDC1 becomes H and the output of the second vehicle speed detection circuit VDC2 becomes L, as shown in Table 2.
Therefore, flip-flop FF1 is set and outputs H. Therefore, transistor Q14
is turned off, turning off transistor Q15. Therefore, the collector potential of transistor Q15 becomes H, so 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 set to 2 to 3 seconds. That is, since the transistor Q17 is turned on for 2 seconds from the time when the vehicle speed becomes 10 km/h or less, H is applied to one input terminal of the NOR gate NOR1 during that time. That is, even if the flip-flop FF2 applies L to the other input terminal of the NOR gate NOR1 during this period, the brake holding is not activated. As mentioned above, the delay circuit DEL causes the vehicle speed to increase to 10
It is prohibited to hold the brakes for 3 seconds from the time the speed drops below Km/h. Therefore, if the vehicle is in a stopped state (vehicle speed is 2 km/h or less) 3 seconds after the vehicle speed becomes 10 km/h or less, brake holding is activated immediately. Furthermore, if the vehicle suddenly locks due to a low μ road or the like, 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 conditions in this case are as shown in Table 3.
This is when the accelerator is pressed. Therefore,
Since accelerator switch SW2 is closed, transistor Q5 is turned on, transistor Q6 is turned on, and NAND gate NA4 of flip-flop FF2 is turned on.
The input terminal of is L. Flip-flop FF2 is reset by this L signal, and its output is inverted to output H. This H output is the Noah gate
In order to apply the voltage to one input terminal of NOR1, the output of NOR gate NOR1 becomes L, which is inverted by NOR gate NOR2, and an H output is applied to NOR gate NOR3. By the way, Noah Gate
NOR3 is inverted and its output becomes L, turning off transistor Q18 and turning off transistor Q28. 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 (energizing the solenoid SL) is released. In this example, a potential circuit is constructed using a large number of transistors, gate circuits, etc., but a microcomputer that operates so as to obtain an output level corresponding to the state of each switch in the same way as in the example is used. The present invention can also be carried out using the following methods.

[Brief explanation of the drawing]

Fig. 1a is a side view showing the vicinity of the foot brake pedal of a vehicle equipped with brake holding means;
The figure is a cross-sectional view taken along line A--A in figure a. Figure 2 shows
It is a circuit diagram showing electronic control means of an example. 110... Brake pedal, 113... Base plate, 122... Plate, 123 (SL)
...Electric coil, 124...One-way clutch, 126...Spring, 127...Yoke,
SW1...Reed switch (vehicle speed detection means), SW
2...brake switch (brake detection means),
SW3...Accelerator switch, SW4...Ignition switch, VD1, VD2...Vehicle speed detection circuit (first vehicle speed judgment means), VD3...Vehicle speed detection circuit (second vehicle speed judgment means), FF1...Flip-flop (second vehicle speed judgment means) 1 Vehicle speed judgment means), DEL...delay circuit (delay means), BIL...brake holding indicator lamp.

Claims (1)

[Claims] 1. Brake holding means capable of holding the operation of the brake mechanism; Vehicle speed detection means for detecting vehicle speed; Brake detection means for detecting braking operation of the foot brake; Receiving inputs from the vehicle speed detection means and the brake detection means. , an electronic control means for operating the brake holding means; In a braking force holding device for a vehicle, the electronic control means is configured to control the vehicle at a predetermined first speed based on the output of the vehicle speed detection means.
A first vehicle speed determining means determines that the vehicle speed is below a predetermined vehicle speed; A second vehicle speed determining means determines that the vehicle is stopped based on the output of the vehicle speed detecting means; The first vehicle speed determining means detects that the vehicle speed is below a predetermined vehicle speed. a delay means for delaying the output by a predetermined time after the delay; a delay means for inhibiting the holding operation of the brake mechanism during the delay by the delay means;
A braking force retaining device for a vehicle, further comprising: a drive means for operating the brake retaining means to retain the brake mechanism when the second vehicle speed determining means determines that the vehicle has stopped.