JPS59186755A - Electromagnetic servo-brake for automobile - Google Patents

Abstract

PURPOSE:To economize electric power, by using an oil pressure keeping mechanism to maintain the oil pressure of the back pressure oil chamber of a master cylinder to dispense with the energizing of an electromagnetic coil for generation of assisting oil pressure when a prescribed braking force should be kept in the stoppage of a vehicle or in the like. CONSTITUTION:When a brake pedal is depressed, a pressure-sensitive rubber plate A and a pressure sensor B generate output voltages ea, eb. In the case of eb>ea, an electromagnetic coil 8b is energized to move a magnetic member 8c leftward to push an assisting piston 7b so that assisting oil pressure is caused in an oil chamber 7d and applied to a back pressure oil chamber 4b through a hose 6b to promote the leftward movement of a piston 3. When the depressing force on the pedal 1 is constant and the voltages ea, eb are equal or nearly equal to each other, a solenoid valve 20 is energized to close to keep the assisting oil pressure in a cylinder subassembly 7 and the energizing of the coil 8b is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic suspension braking device for an automobile, namely
The present invention relates to a brake device that uses L output to obtain assist force.

Automobile brakes are equipped with a booster that adds an assist force to the brake pedal depression force, but conventional devices of this type generally utilize negative pressure in the intake of an ennon. This is an intermediary between the brake mask cylinder and the brake pedal. When the brake pedal is depressed, the piston of the mask cylinder is actuated by negative pressure.
It is an IC.

However, with such a single-sound force (servo) brake, it is difficult to adjust the engine suction negative pressure, so it is not possible to arbitrarily set the boost characteristics. It is not possible to perform fine-grained control to obtain optimal operability, such as increasing the

Moreover, when braking while the engine is stopped while driving, no boosting effect can be obtained, and in cars and electric cars equipped with supercharged engines that do not have suction negative pressure, Not applicable.

Therefore, an electromagnetic servo brake device that uses electromagnetic force instead of negative pressure may be considered. In other words, think of a servo (boost) brake system in which an electromagnet that turns on when the brake pedal is depressed acts on a magnetic member fixed to the bushing rod of the brake mask cylinder, and obtains an assist force by electromagnetic force in response to the depression of the brake pedal. Do 1. In such five types of electromagnetic brakes, for example, by electrically detecting the pedal stroke and adjusting the current supplied to the electromagnet according to the detected stroke, boosting characteristics can be obtained according to the size of the pedal stroke. Do it.

With this method, it is possible to obtain desirable boosting characteristics according to the depression stroke, and since it does not utilize engine negative pressure, even when the engine is stopped, it is possible to obtain the desired boosting characteristics.
Utilizing the negative pressure of the rice used, it is possible to obtain a sardep V -- IF -- which has a great practical advantage compared to using one rice.

1, for example, Japanese Patent Application Laid-Open No. 7-7/Otsu No. 72 shows the use of electromagnetic force for emergency braking. It applies sudden braking, and is not a servo brake.

An object of the present invention is to save power in a magnetic brake system for an automobile as described above.

The one-magnetic servo brake system for an automobile according to the present invention includes a brake mask cylinder having a brake oil chamber and a back pressure oil chamber, an oil supply means for supplying oil so that the back pressure oil chamber of the brake mask cylinder is always filled with oil; magnetizing means for generating braking oil pressure in the braking oil chamber of the brake mask cylinder by the UiB force; a depressing force detecting means for detecting the depressing force applied to the brake pedal; (1) a first control means for controlling the magnetic means; a hydraulic pressure holding unit for maintaining the hydraulic pressure in the back pressure oil chamber of the brake mask cylinder; a pedal force for receiving the output of the pedal force detection means and detecting that there is no change in the pedal force; A second control means is provided for operating the oil pressure holding machine oil pressure and cutting off power supply to the magnetizing means upon receiving the output from the no-change detection means and the no-change cough pedal force detection means. It is characterized by: 1- That is, the hydraulic pressure in the back pressure oil chamber of the electromagnetic servo brake system of the automobile of the present invention and the mask cylinder is held by the hydraulic pressure holding mechanism, and the braking hydraulic pressure is maintained by this mechanism, so that, for example, when the vehicle is stopped When a constant braking force is to be maintained, as in
Therefore, it is possible to save power.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electromagnetic servo brake system for an automobile according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 illustrates an electromagnetic servo brake device according to a first embodiment of the invention.

An operating rod 2 is connected to the brake pedal 1 via a connecting shaft 1a, and a conductive plate 2a is fixed to the tip thereof. On the other hand, the piston 3 of the brake mask cylinder is arranged coaxially with the operating rod 2,
A conductive plate 3a is fixed to the end of the operating rod, and both grooved electric plates 2a and 3a are arranged parallel to each other, and a pressure-sensitive rubber sheet A is held between them. These two conductive plates 2a.

38 is provided with an output terminal, one of which is grounded, and the other output terminal a is provided with a conductive plate and a rod (or piston) to which this is fixed.
are insulated from each other.

(In this embodiment, the output terminal on the operating rod side is grounded, and the piston 3 of the mask cylinder and the conductive plate 3a
are insulated. ) The mask cylinder 40 oil chamber C is divided into a brake oil chamber 4a and a back pressure oil chamber 4b by the piston 3, and a spring 5 placed in the control oil chamber 4a moves the piston 3 to the right side in the figure, that is, to the brake side. The pressure sensor B provided in the mask cylinder 4 is biased in the direction of pushing back the pedal, and a portion (sensor portion) thereof communicates with the brake oil chamber 48 .

On the other hand, the sag cylinder assembly 7, which is connected to the mask cylinder 4 through two hoses (tubes) 6a and 6b, is a sub-cylinder 7a.

Assist oil chamber 7d formed by the sub-piston 7b1, the suge ring 7c, the sub-cylinder 7a, and the sub-piston 7b.
The end of the sub-piston 1b protruding outward from the sub-cylinder 7a is directly connected to the magnetic member 8c of the electromagnetic means 8. This magnetic member 8C is movable in the axial direction, and an iron case 8a containing an electromagnetic coil 8b is fixedly disposed around the magnetic member 8C.
When current is applied to b, the magnetic member 8c is moved to the left in the figure (in the direction of pushing the sub-piston 7b) by the magnetic force. In this way, by energizing the electromagnetic means 8 made up of the case 8a, the electromagnetic coil 8b, and the magnetic member 8c, the sub-piston 7b is driven, and hydraulic pressure can be generated in the assist oil chamber 7d of the sub-cylinder assembly 7. can.

When the electromagnetic means 8 is not energized, the magnetic member WC is returned to the right by the spring 1c via the piston 7b.

The resistance value of the pressure sensor A is proportional to the pressure VC generated by the force applied to the brake pedal, and the resistance value of the pressure sensor B is inversely proportional to the oil pressure in the brake oil chamber 4a.

Here, for ease of comparison, the hydraulic pressure generated in the brake oil chamber 4a by only the force applied to the brake pedal (this is when the hydraulic pressure in the back pressure oil chamber 4b is zero, and the pressure is sensitive) is proportional to the pressure acting on A. ) and the resistance value to the pressure-sensitive rubber sheet, the pressure-sensitive electrical characteristics become such that the resistance decreases as the pressure increases, as shown by the straight line (Δ) in FIG.

In addition, the relationship between the resistance value of the pressure sensor B and the oil pressure in the brake oil chamber 4a is also shown by the straight line (8) in FIG. have However, when the pressure is zero (both the brake pedal depression force j15 and the assist oil pressure are zero), both resistance values are equal at rO, but the rate of decrease in the resistance value as the pressure increases is different, and the resistance to the pressure-sensitive rubber sheet is The lower do rate is thicker. For example, in this example, it is known that the rate of decrease of pressure sensitive rubber seal A is about λ times that of pressure sensor B.

A conductive plate 2a sandwiching such a pressure sensitive rubber sheet 8.

As shown in FIG. 2, the ungrounded output terminal a of 3a and the ungrounded output terminal 7 of the pressure sensor B are connected to the power supply Vcc through resistors E and F, each having the same resistance value. These output terminals a and b:
Connect the comparator 110 input side π so that the terminal a is the (-) side and the terminal is (+) 11111vc. The output of this comparator 11 is connected to the pace of the transistor 12, and the emitter of this transistor is grounded, and the collector' is connected to the output terminal d of the electromagnetic coil 8b (7). One output terminal C
is a J concubine with Kaigen Vcc.

A sixth magnetic servo brake device is added to the '4 magnetic servo brake device configured as described above.
When there is no pedal force acting on brake pedal 1,
The pressure of the pressure-sensitive rubber sheet A and the oil pressure of the brake oil chamber 4a are both zero, and the resistance values of the pressure-sensitive rubber sheet A and the pressure capsessor B are rO as shown in FIG. Therefore, the output terminals a and b17) bending pressure e8+eb shown in the circuit diagram of FIG. 2 become equal. In other words, the inputs of the comparator 11 become equal and the output becomes Low level, so the transistor 12 becomes OF.
F, and the electromagnetic coil 8b is not energized either. Therefore, no assist hydraulic pressure is generated.

Next, think about when you press the brake pedal with a certain amount of force. Hydraulic pressure fP of the brake oil chamber 4a generated by this one foot force
When the electromagnetic means 8 is in operation (a and i), the resistance value of the pressure-sensitive rubber sheath (A) is j+ as shown in Fig. 3.
, the pressure sensor B has a low resistance value r2. rz,>r+
Therefore, the heavy pressures θ8 and θ at the output terminal a of the pressure sensitive rubber plate A and the output terminal of the pressure sensor B. is θb〉θ8
becomes. Therefore, comparator 1117) output %'L HIG
It becomes H level, transistor 12 is turned on, and 'α
α cocoil 8b11'h be electrified. Therefore, in FIG. 1, the magnetic part 8c is moved to the left in the figure, and the assist piston 1b is pushed 1. , assist oil 4a 7
Generate dK assist hydraulic pressure. This assist hydraulic pressure is transmitted to the back pressure oil chamber 4b by the hose 6b, and the piston 3 is pushed to the left in the figure by the hydraulic pressure generated there.
Ru. Therefore, the oil pressure in the brake oil chamber 4a increases, the braking force increases, and the resistance value of the pressure sensor B decreases. On the other hand, since the resistance value of the pressure-sensitive rubber seal A does not change because the brake pedal force is constant, the input voltage of the comparator 11 is such that ea remains the same and only eb decreases. Then, at the time when ea=81), the output of this comparator becomes Low level, the transistor 12 is turned off, and the electromagnetic coil 8b is also turned off.
becomes. Therefore, the assist oil pressure decreases, but when the assist oil pressure decreases, the braking oil pressure decreases and becomes e8<eb.
Since the electromagnetic coil is turned on, the oil pressure in the brake oil chamber 4a is controlled so that the voltage e1 at the output terminal determined by the resistance value of the pressure sensor B converges to the point where eb=86.
reactor. That is, in FIG. 3, move from point (Pa, rz) to the lower right on point (8) to a point (pb) where the resistance value becomes equal to the resistance value r+ of pressure-sensitive rubber sheet A.

rt).

As described above, it is possible to obtain an electromagnetic servo brake device that can double the hydraulic pressure Pa generated by the brake pedal force to the pressure Pb with the assistance of the assist hydraulic pressure obtained by the electromagnetic means. . However, in the intuitive nervous brake system having the above structure, as long as the driver continues to press the brake pedal 1, the electromagnetic coil 81)K power is substantially always supplied, which is uneconomical. Therefore, in the present invention, the oil supply to the sub-cylinder assembly 7 from the reserve tank R 4 M R+ '
VC1 maintains the assist oil pressure of the sub-silling assembly 7 with the oil holding mechanism! ! 20 pulps are provided, and when the pressing force on the brake pedal 1 remains unchanged, the electromagnetic pulp 20 is closed and the supply of force to the electromagnetic coil 8b is cut, thereby saving power. .

The electromagnetic pulp 20 is controlled by a control circuit 21. This control circuit 21 has a switching transistor 22 (36"), the collector of which is connected to the electromagnetic coil of the electromagnetic pulp 20. The base of this transistor 22 is connected to the output terminal of an AND circuit 23. are connected to both input terminals of the AND circuit 23, and comparators 24 and 25 are respectively connected to both input terminals of the AND circuit 23.One input terminal of the comparators 24 and 25 is connected to the ratio Pl circuit shown in FIG. 11 output ends are connected
6, and the other input terminal has, for example, −/3rV and 10/
One port of the constant pressure component VEE is connected. Note that the output characteristic of the comparator 11 is (a) in Fig. 4L.
11, as shown in l, H Lebel +/jV
It consists of a restricted area of , a restricted area of 1/V which is a low level, and a linear area between these.

In addition, the output characteristics of the comparators 24 and 25 are shown in (b) of Fig.
and as shown in (C).

Next, the operation of the control circuit 21 having the configuration described above will be explained.

When the pressing force on the pedal 1 is constant and the braking oil pressure reaches a predetermined boost-related value, both input terminals of the comparator 11 '>R, ItE
ea and Bb are equal or close to each other. Therefore, the output pressure e of this comparator 11 is increased. , is the voltage within the linear region shown in the above figure (allc), that is, the voltage between +/jV and -/jv. e
Both 03 are H Lebel and Buero. The output of the first and second AND circuits 23 is
Become an HIV bell and turn on the switching transistor 22. As a result, the '1PL trowel valve zO is energized and operated, and the assist hydraulic pressure within the sub-cylinder assembly 7 is maintained.

The output terminal of the AND circuit 23 and 1J of the comparator 11
Between the force ends Kt, 2'l'ff, magnetic valve 20]
)＼Operation: 1f Kokishi(,■ Coil 8c of magnetic means 8
A transistor 26 for cutting the conductor 11 to is connected to the ground line. Therefore, when the AND circuit 23 outputs the H1 signal, the transistor Z6 remains on, so that the output terminal of the transistor 11 is grounded. As a result, the transistor 12 is turned off and the 11h current to the coil 8b is cut off. As described above, in the Jd of the present invention, when the pedal force is constant, the assist hydraulic pressure of the pear cylinder assembly is maintained, and the power to the electromagnetic means is cut off, thereby achieving power saving.

The above embodiment includes a sap cylinder assembly and a 1 iB
This is a tie that generates assist hydraulic pressure in this sub-cylinder assembly by the action of the means, and generates boosted braking hydraulic pressure in the mask cylinder assembly by this assist hydraulic pressure.As shown in FIG. 5, the pressure-sensitive rubber sheet A An electromagnetic means 8 may be provided on the operating rod 2 between the pedal force detection means and the mask cylinder, and the electromagnetic force of the electromagnetic means 8 may be applied directly to the piston 3 to generate a boosted braking hydraulic pressure. . In this embodiment, oil is directly supplied to the back pressure oil chamber 4b of the mask cylinder assembly through the oil passage R1, even if the oil passage R1 is in the oil passage R1. The hydraulic pressure in the back pressure oil chamber 4b can be maintained by operating the electromagnetic pulp 20 provided in the back pressure oil chamber 4b. Note that the same control circuit as in the first embodiment can be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the main bag portion of the electromagnetic servo brake device according to the first embodiment of the present invention. A circuit diagram showing the circuit. Figure 3 shows the pressure/resistance ratio of the pressure-sensitive rubber sheet used for the pedal force detector and braking oil pressure detector. Figures 1 and 5 show the output performance of the comparator and AND circuit used in the air control output circuit. Part 1 - Schematic diagram. DESCRIPTION OF SYMBOLS 1... Brake pedal, 2... Operating rod, 4... Mask cylinder, 1... Sub cylinder assembly, 8... Electromagnetic means, 20... Electromagnetic pulp. Figure 1 Figure 3 Figure 5

Claims (1)

[Claims] Brake mask cylinder with brake oil chamber and back pressure oil chamber,
An oil supply means for constantly supplying oil to the back pressure oil chamber of the brake mask cylinder, an electromagnetic means for generating braking oil pressure in the brake oil chamber of the brake mask cylinder by electromagnetic force, and a pedal force applied to the brake pedal. a pedal force detecting means for detecting, a braking oil pressure detecting means for detecting the braking oil pressure generated by the brake mask cylinder, and a brake oil pressure detecting means for detecting the braking oil pressure generated by the brake mask cylinder; a first control means for controlling the electromagnetic means; a hydraulic pressure holding mechanism for holding the hydraulic pressure in the back pressure oil chamber of the brake mask cylinder; and a pedal force no-change detection unit for receiving the output of the pedal force detection means and detecting that there is no change in the pedal force. and the output from the pedal force unchanged detection means? The vehicle is equipped with a second control means for operating the hydraulic pressure holding mechanism and cutting off power supply to the electromagnetic means.
te servo brake device.