JP3079239B2 - Operation reaction force generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation reaction force generator used for an electric / hydraulic braking device of an automobile, and more particularly to a master cylinder operated by an operator and an operation discharged from the master cylinder. And a stroke accumulator provided with a pressure accumulator for resiliently receiving oil.

[0002]

2. Description of the Related Art Such an operation reaction force generator is already known, for example, as disclosed in Japanese Patent Application Laid-Open No. 4-95556.

[0003]

By the way, in the conventional operation reaction force generating device, since only one accumulator has the pressure accumulating chamber for receiving the hydraulic oil from the master cylinder, the operation accumulator is not provided between the master cylinder and the stroke accumulator. If the hydraulic system fails, the stroke accumulator becomes inoperable and the desired operation reaction force cannot be obtained.

The present invention has been made in view of such circumstances, and comprises two hydraulic systems between a master cylinder and a stroke accumulator so that a predetermined operation can be performed even if one of the hydraulic systems fails. A compact operation reaction force generator capable of exhibiting desirable characteristics in terms of operation feeling, in which a reaction force is obtained, and the operation reaction force gradually increases in the first half of the stroke of the operator and rapidly increases in the second half. Aim.

[0005]

In order to achieve the above object, the present invention provides a master cylinder having a tandem type having a pair of independent first and second output ports, and a pair of cylinders. A housing having a hole, first and second pressure accumulating pistons which slidably fit into the pair of cylinder holes to define first and second pressure accumulating chambers and have inner ends opposed to each other; A spring interposed between the pistons and compressed by the forward movement of both pistons due to the expansion of the capacity of the first and second pressure accumulating chambers, and disposed between each of the pressure accumulating pistons and the housing, when each of the pressure accumulating pistons has advanced a predetermined stroke The first and second leaf springs are bent to form a stroke accumulator, and the first and second pressure accumulating chambers have the first and second pressure accumulators.
The second output ports are connected to each other.

[0006]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an entire vehicle braking system to which the present invention is applied. In the figure, 1 indicates a brake pedal as operator, also B _FL left front brake, B _FR right front wheel brake, B _RL left rear wheel brake, B _RR is the right rear wheel brake Show. Brake pedal 1
Is connected to a master cylinder M via a push rod 3. The master cylinder M is of a known tandem type, that is, a pair of front and rear pistons 2f and 2r are fitted in the cylinder body 5, and the front end of the push rod 3 is connected to the rear piston 2r. The front hydraulic chamber 3 is located between the front end wall of the cylinder body 5 and the front piston 2f.
2f and a rear hydraulic chamber 3 between the pistons 2f and 2r.
2r are independently defined, and the front and rear hydraulic chambers 32
The return springs 33f and 33r for urging the front and rear pistons 2f and 2r in the retreating direction are stored in f and 32r, respectively.

The cylinder body 5 includes front and rear hydraulic chambers 32.
f, 32r, respectively, are provided with _first and second output ports 4 ₁ , 4 _2.
4 _1, 34 ₂ stroke accumulator S via is connected.

The push rod 3 is provided with a tread force sensor 6 for detecting a tread force applied to the brake pedal 1, and detects a tread force signal output from the tread force sensor 6 and that a wheel is about to be locked. The control device 7 is operated by the lock approach signal output from the lock approach sensor 8.

Electrically actuated actuators 10 _FL and 10 _FR are individually connected to the left front wheel brake B _FL and the right front wheel brake B _FR , respectively, and are respectively connected to the left rear wheel brake B _RL and the right rear wheel brake B _RR . Is connected to one electrically operated actuator 10 _R in common.
_FL , 10 _FR and 10 _R are operated by the control device 7.

Each of the electrically operated actuators 10 _FL , 10
_FR and 10 _R are provided with a housing 12 having a cylinder hole 11 with a closed front end, a spool 13 slidably fitted in the cylinder hole 11, and abutting against the spool 13, and sliding into the cylinder hole 11. A reaction force piston 14 that fits freely,
An electric operating portion 15 is attached to the housing 12 with the operating rod 15a abutting on the rear end surface of the reaction force piston 14.

The front end face of the spool 13 and the cylinder hole 11
An output chamber 16 is defined between the front end walls of the output chamber 16.
Output ports 17 connected to the brakes B _FL and B
_FR , B _RL and B _RR are connected. The output chamber 16 houses a return spring 18 for urging the spool 13 in the backward direction.

The inner surface of the cylinder hole 11, the spool 13
The reaction pressure piston 14 defines an output pressure action chamber 19 in which the front end face of the reaction force piston 14 faces. A communication passage 20 communicating with the output chamber 16 is formed in the spool 13 over the entire length in the axial direction, and a through hole 21 is formed in the reaction force piston 14 for communicating the communication passage 20 with the output pressure action chamber 19. You. Thus, the reaction force piston 14 is provided with the output pressure action chamber 19.
The spool 13 moves while following the reaction force piston 14 by the spring force of the return spring 18.

The housing 12 is provided with a release port 23 and an input port 24 arranged in front and rear, and the spool 13 is arranged in the first and second valve holes 25 and 26 guides communicating with the communication passage 20. The valve holes 25 and 26 are provided in the second position when the spool 13 is located at the retreat limit.
The valve hole 26 is closed and the first valve hole 25 communicates with the release port 23. When the spool 13 advances, the first valve hole 25 is closed and the second valve hole 26 is communicated with the input port 24. You.

The input port 24 has a hydraulic supply 27
A reservoir 28 is connected to the release port 23, respectively.

The hydraulic supply source 27 includes a hydraulic pump 29 for pumping from a reservoir 28, an accumulator 31 connected to the discharge side of the hydraulic pump 29, and a pressure switch 30 for controlling the operation of the hydraulic pump 29. The input port 24 is connected to the discharge side of the hydraulic pump 29.

The electric actuator 15 of each electric actuator 22 is controlled by the control device 7 to control the amount of applied electric power. A forward pressing force can be applied.

FIG. 2 is a longitudinal section of the stroke accumulator S.
FIG. In the figure, the stroke accumulator
The S housing 35 is a cylindrical housing with both ends open.
Body 36 and bolts on both end surfaces of the housing body 36.
A pair of housing end plates 37 joined by₁, 37
_TwoAnd a central portion of the housing body 36 in the axial direction.
Has an annular stopper wall 36a protruding from its inner surface.
It is formed. Also, the housing end plate 37₁, 37_TwoNisso
Cylinder holes 39 of the same diameter opening at the center of their inner surfaces₁,
39_TwoAnd first and second pressure accumulating pistons 4
0₁, 40_TwoAre fitted via the sealing members 41, respectively.
It is. These pressure accumulating pistons 40₁, 40 _TwoIs the cylinder bore
39₁, 39_TwoBetween the first and second accumulator chambers 4
2₁, 42_TwoThese pressure accumulating chambers 42₁,
42_TwoThe first and second input ports 43 connected to₁, 43_TwoTo
The first and second conduits 34₁, 34_TwoAre connected to each other
You.

[0019] First, the second accumulator piston 40 _1, 40 ₂ of the inner end, a disc-shaped plate spring 44 ₁ facing on both sides of the stopper wall 36a, 44 ₂ are fixed respectively by screws 45 You. And Thus, first, when the second accumulator piston 40 _1, 40 ₂ is located at the retraction limit, i.e. when the corresponding accumulator chamber 42 _1, 42 ₂ of the volume is made to minimize,
Predetermined distance D is maintained between each plate spring 44 _1, 44 ₂ and the stopper wall 36a.

[0020] Between the two accumulator pistons 40 _1, 40 _2, a coil spring 46 which urges them to the separating direction is interposed. Both ends of the coil spring 46, the leaf spring 44 ₁ by screws 45, 44 ₂ accumulator piston 40 ₁ with,
Is fixed to 40 ₂ is held in the retainer 47.

Next, the operation of this embodiment will be described.

If the master cylinder M is actuated by depressing the brake pedal 1 to perform braking, the pedaling force sensor 6 detects the pedaling force applied to the brake pedal 1 and generates a corresponding pedaling force signal. The control device 7 controls the actuators 10 _FL , 10 _FR , 1 according to the strength of the pedaling force signal.
Activate the electric operating unit 15 of 0 _R to move the spool 13 forward. When the spool 13 moves forward, the first valve hole 25 is closed and the second valve hole 26 communicates with the input port 24, so that the hydraulic pressure of the hydraulic pressure supply source 27 is supplied to the output chamber 16 via the second valve hole 26. Then, the pressure in the chamber 16 is increased, and the oil pressure is output from the output port 17 to operate the corresponding wheel brakes B _FL , B _FR , B _RL , and B _RR .

At the same time, the oil pressure in the output chamber 16 is also transmitted to the output pressure action chamber 19, and in response to this, the reaction force piston 14
Exerts a reaction force in the retreating direction on the operating rod 15a of the electric operating unit 15, so that the position of the spool 13 is controlled by the balance between the operating force of the electric operating unit 15 and the reaction force of the reaction force piston 14. Therefore, if the operating force of the electric operating unit 15 is superior, the spool 13 occupies the forward position and the second valve hole 26
To the input port 24 to raise the pressure in the output chamber 16. If the reaction force of the reaction force piston 14 wins, the spool 13 retreats to close the second valve hole 26 and to release the first valve hole 2.
5 is communicated with the release port 23 to depressurize the output chamber 16. Thus, during normal braking, the hydraulic pressure in the output chamber 16
That is, the braking force is controlled to a value corresponding to the operating force of the electric operating unit 15, that is, the pedaling force on the brake pedal 1.

When a certain wheel is about to be locked during such braking, the lock approach sensor 8 detects this state and issues a lock approach signal, and upon receiving the signal, the control device 7 applies the pedaling force to the brake pedal 1. Irrespective of the electric actuator 15 of the actuator 10 _FL , 10 _FR , 10 _R corresponding to the wheel.
The pressure in the output chamber 16 is reduced by appropriately reducing the operating force of the wheel, thereby preventing the locked state of the wheel.

By the way, at the time of depression of the brake pedal 1, front and rear hydraulic chamber 32f, hydraulic oil first 32r, the second output port 4 _1, 4 ₂ from the first, second conduit 34 _1, 3
4 ₂ first stroke accumulator S via, is supplied to the second accumulation chamber 42 _1, 42 _2, first accordingly, the second
Since the pressure accumulating pistons 40 ₁ and 40 ₂ advance so as to approach each other, first, the coil spring 46 is compressed, and accordingly, the repulsive force of the coil spring 46 is reduced by the first and second pressure accumulating pistons 4.
0 _1, 40 by acting on the _2, first, second accumulation chamber 42 _1, 42 ₂ or before, hydraulic pressure is generated rear hydraulic chamber 32f, to 32r, brake pedal 1 as this operation reaction force
Side, and the operation reaction force increases as the depression amount of the brake pedal 1 increases.

When the depression amount of the brake pedal 1 exceeds a predetermined value, the stroke accumulator S
First, first advancing together with the second accumulator piston 40 _1, 40 _2, begins to flex in contact with the dish-shaped on both sides of the second plate spring 44 _1, 44 ₂ of the outer peripheral portion stopper wall 36a, which the Along with 1, first with the repulsive force of the second leaf spring 44 _1, 44 repulsive force generated in _two coil springs 46, the second accumulator piston 4
0 _1, because they act to 40 _2, the operation reaction force transmitted to the brake pedal 1 side is gradually more and more increased.

FIG. 3 is a change in the operation reaction force is a characteristic diagram showing with changes in amount of depression of the brake pedal 1, in the figure, D'both leaf springs 44 _1, 44 ₂ stopper wall 36a
Shows the amount of depression of the brake pedal 1 until it comes into contact with.
As is apparent from FIG. 5, the operation reaction force increases proportionally according to the linear spring constant of the coil spring 46 until the depression amount of the brake pedal 1 reaches D 'from zero, and D'
More than the operation reaction force is 2 when flexing the linear spring constant of the coil spring 46 and the leaf spring 44 _1, 44 ₂ of the dish-shaped
It increases at an accelerating rate in accordance with a spring constant having a quadratic curve. Thus, within the limited depression amount of the brake pedal 1, the operating force, that is, the rising of the pedaling force is controlled gently in the first half and sharply in the second half, and the pedaling force is detected by the pedaling force sensor 6 as described above, and The applied braking force is applied to the wheel brakes B _FL , B _FR , B _RL , and B _RR .

Next, the front and rear hydraulic chambers 32f and 32r will be described.
A case where one of the hydraulic systems has failed will be described.
You. If the hydraulic system in the rear hydraulic chamber 32r fails,
2 accumulator piston 40_TwoIn situations where the
When the master cylinder M is operated by the rake pedal 1,
From the front hydraulic chamber 32f of the normal hydraulic system to the first accumulator 42
₁Is supplied to the first pressure accumulating piston 4
0₁Only the coil spring 46 and the
One leaf spring 44₁Are sequentially compressed and bent,
Accumulator 42₁Or hydraulic pressure is generated in the front hydraulic chamber 32f,
An operation reaction force can be transmitted to the brake pedal 1 side.
However, the second pressure accumulation piston 40_TwoDoes not work,
To obtain the same operation reaction force as normal, that is, the pedaling force,
The amount of compression of the spring 46 and the first leaf spring 44₁Normal bending amount
Brake pedal 1
Is twice as large as the normal operation.

[0029] When the hydraulic system of the front hydraulic chamber 32f is defective, only the second accumulator piston 40 ₂ is advanced to the same action as above can be obtained it will be appreciated.

[0030] Figure 4 shows a modification of the stroke accumulators S, instead of the coil spring 46 of the previous embodiment is obtained by interposing a cylindrical rubber spring 48 on both accumulator pistons 40 _1, 40 between ₂ . The rubber spring 48 is 2 in the axial direction.
Aliquoted, that both halves 48 _1, 48 ₂ are bonded to the corresponding leaf spring 44 _1, 44 _2, each half 48 _1, 4
In the hollow portion of the 8 _2, the plate spring 44 ₁ by screws 45,
44 fixation of ₂ to accumulator piston 40 _1, 40 ₂ is performed.

In FIG. 4, parts corresponding to those of the previous embodiment are denoted by the same reference numerals.

In each of the above embodiments, the essential features of the present invention are described.
Various design changes are possible without departing from the spirit.
For example, the leaf spring 44₁, 44_TwoControl the spring constant
You may provide a plurality of radial slits for controlling,
The leaf spring 44₁, 44_TwoTo form a ring
The pressure accumulating piston 40 is fixed to the₁, 40 _Two
Pushes the inner peripheral portion of the leaf spring when the
You may make it.

[0033]

As described above, according to the present invention, the master cylinder is formed in a tandem type having a pair of independent first and second output ports, while a housing having a pair of cylinder holes is provided. First and second pressure accumulating pistons which slidably fit into the pair of cylinder holes to define first and second pressure accumulating chambers and have inner ends opposed to each other, and interposed between the pistons. A spring is provided between the pressure accumulating piston and the housing, and is bent when the pressure accumulating piston advances by a predetermined stroke or more. 1st, 2nd
A stroke accumulator is formed from the leaf spring, and the first and second output ports are respectively connected to the first and second pressure accumulating chambers. Therefore, a hydraulic system such as a second system is formed between the master cylinder and the stroke accumulator. Even if one of the hydraulic systems fails, the stroke accumulator can be operated to obtain a predetermined operation reaction force.
In addition, the stroke accumulator has the characteristic that the operation reaction force is gradually increased in the first half of the operation stroke of the operator and rapidly increased in the second half by the cooperation of the compression spring and the leaf spring. A good operation feeling can be obtained within the stroke. Further, the stroke accumulator alone performs two types of pressure accumulating functions, so that it can contribute to downsizing of the entire apparatus.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part of an automobile braking device provided with an operation reaction force generating device of the present invention.

FIG. 2 is a longitudinal sectional side view of a stroke accumulator in the operation reaction force generator.

FIG. 3 is a characteristic diagram of the stroke accumulator.

FIG. 4 is a longitudinal sectional side view showing a modified example of the stroke accumulator.

[Explanation of symbols]

M Master cylinder S Stroke accumulator 1 Brake pedal as operator 4 ₁ First output port 4 ₂ Second output port 35 Housing 39 ₁ Cylinder hole 39 ₂ Cylinder hole 40 ₁ First pressure accumulating piston 40 ₂ Second pressure accumulating piston 42 ₁ First 1 pressure storage chamber 42 ₂ second pressure storage chamber 44 ₁ first leaf spring 44 ₂ second leaf spring 46 coil spring 48 rubber spring

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 13/12

Claims (1)

(57) [Claims] A master system operated by an operator (1).
Discharged from the cylinder (M) and the master cylinder (M)
With a pressure accumulator chamber for resiliently receiving hydraulic oil
Operation reaction force generator consisting of a accumulator (S)
In this case, the master cylinder (M) is divided into a pair of independent first and second cylinders.
Output port (4₁, 4 _Two) With tandem type
On the other hand, a pair of cylinder holes (39₁, 39_TwoHaving
A housing (35) and the pair of cylinder holes (3
9₁, 39_Two) And slidably fitted to the first and second accumulators
(42₁, 42_Two) And the inner ends are
First and second pressure accumulating pistons (40₁, 40_Two)
And both pistons (40₁, 40_Two) Interposed between
First and second accumulators (42₁, 42_Two)
Both pistons (40₁, 40_Two) Is compressed by the advance
Springs (46, 48) and each pressure accumulating piston (40₁, 40
_Two) And the housing (35), each pressure accumulating pi
Tons (40₁, 40_Two) Is more than predetermined stroke (D)
The first and second leaf springs (44₁, 44
_Two) To form a stroke accumulator (S),
The first and second accumulators (42₁, 42_Two) To the first,
The second output port (4₁, 4_Two)
An operation reaction force generator.