JP2000135976A - Brake stroke simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily change the operation feeling of a brake operating element without needing to change parts by providing a regulating means for variably regulating a sliding range of a piston of a hydraulic pressure absorber against the energizing force of an energizing means by hydraulic pressure supplied from a hydraulic pressure converting device. SOLUTION: Hydraulic pressure generated to a tandem master cylinder 2 acts upon a first piston 6b in a first cylinder assembly 6 and a piston 7b in a second cylinder assembly 7. At this time, reaction caused by a compressed reaction spring 6c and reaction spring 7c is generated to provide a driver with an operation feeling of a depressing response of a brake pedal 1. When the piston 7b abuts on a stopper bolt 7d, reaction changes. When the protruding quantity of the stopper bolt 7d into the cylinder 7a is shortened, the abutting position of the piston 7b on the stopper bolt 7d moves to the inner side, so that a stroke characteristic changes, and the operation feeling of the brake pedal 1 changes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system for a vehicle, and more particularly to a brake pedal for driving and controlling a hydraulic control valve provided between a wheel cylinder and a hydraulic pressure source for supplying high-pressure brake fluid. Also, the present invention relates to a brake device that generates a braking force in accordance with an operation force of a brake lever (brake operator) in the wheel cylinder, and relates to a brake stroke simulator device for giving a driver an operation feeling of the brake pedal or the brake lever.

[0002]

2. Description of the Related Art An example of this type of brake device will be described with reference to FIG. The brake device 101 includes a master cylinder 103 that generates a hydraulic pressure according to an operation force of a brake pedal 102 by a driver, and a brake cylinder 101 that applies a brake stroke discharged from the master cylinder 103 and accumulates pressure to provide a pedal stroke. Hydraulic absorber 104
A wheel cylinder 105 for generating a braking force on the wheels by the supplied brake hydraulic pressure, a hydraulic pump 106 for generating high-pressure brake fluid for supplying hydraulic pressure to the wheel cylinder 105, a motor 107, an accumulator 108, Hydraulic pressure supply source 11 including reservoir 109 and the like
0, a hydraulic pressure control valve 111 for controlling the supply and discharge of brake fluid between the hydraulic pressure supply source 110 and the wheel cylinder 105;
Based on the hydraulic pressure of the master cylinder 103, the hydraulic pressure control valve 11
1 for controlling the electronic control unit 1.

Normally, the driver's brake pedal 1
02, the brake fluid discharged from the master cylinder 103 through the inlet valve 117 through the hydraulic pressure absorber 104
To accumulate the pressure, apply a stroke and a reaction force corresponding to the depression force of the brake pedal 102, detect the hydraulic pressure of the master cylinder 103 at this time by a hydraulic pressure sensor 113, and, based on the hydraulic pressure, an electronic control unit. The hydraulic pressure control valve 111 is controlled by 112 to supply a hydraulic pressure from the hydraulic pressure supply source 110 to the wheel cylinder 105 at a predetermined boosting ratio to generate a braking force according to the operation of the brake pedal 102. In addition, anti-lock control is performed by determining the slip state of the wheel based on the rotational speed information of the wheel from the speed sensor 114 and controlling the hydraulic pressure control valve 111 based on this to appropriately adjust the braking force on the wheel. And traction control.

At this time, the hydraulic pressure of the wheel cylinder 105 is detected by a hydraulic pressure sensor 115. If the hydraulic pressure does not increase during the braking operation, the fail-safe valve 116 and the inlet valve 117 are switched to the positions shown in FIG. The hydraulic pressure generated by the cylinder 103 is directly applied to the wheel cylinder 10
5, the braking force at the time of failure is secured.

Here, the brake stroke simulator device 118 increases the reaction force of the brake pedal 102 by the master cylinder 103 and the hydraulic pressure absorber 104 when the input (pedal force) of the brake pedal 102 increases. This is a part having a function of giving an operational feeling (so-called brake feeling) to the user. However,
The configuration of the conventional brake stroke simulator device is as follows:
The stroke characteristic of the brake pedal with respect to the depression force of the brake pedal has a fixed configuration.

[0006]

As described above, in the conventional brake stroke simulator, the stroke characteristics of the brake operator cannot be freely changed according to the driver's preference or the driving condition of the vehicle. Furthermore, even when the stroke characteristics of the brake operator are changed in accordance with the characteristics of the vehicle, parts must be changed in order to change the stroke characteristics, so that many parts have to be set.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention drives a hydraulic pressure control valve provided between a wheel cylinder and a hydraulic pressure source for supplying high-pressure brake fluid. A brake stroke simulator that is provided in a brake device that controls and generates a brake force in accordance with the operation force of a brake operator in the wheel cylinder, and that applies a stroke in accordance with the operation force to the brake operator. The stroke simulator device includes a hydraulic pressure conversion device that converts the operating force of the brake operator into a hydraulic pressure and outputs the hydraulic pressure, and a plurality of hydraulic pressure absorbers for absorbing the output hydraulic pressure from the hydraulic pressure conversion device. Each of the hydraulic pressure absorbers is slidably provided in the cylinder to define a hydraulic pressure absorption chamber communicating with the hydraulic pressure conversion device in the cylinder. And a biasing means for biasing the piston toward the side for reducing the hydraulic pressure absorbing chamber, wherein at least one of the plurality of hydraulic pressure absorbing bodies has the hydraulic pressure It is characterized in that a regulating means for variably regulating a sliding range of the hydraulic pressure absorber against the urging force of the urging means of the piston by the hydraulic pressure supplied from the pressure conversion device is provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of a brake stroke simulator device according to the present embodiment.
Is a brake pedal (brake operator), 2 is a tandem master cylinder (hydraulic pressure generating means), 2a is a primary side of the tandem master cylinder 2, and 2b is a secondary side of the master cylinder 2. Reference numerals 3 and 4 denote a plurality of fail-safe valves (not shown) (each fail-safe valve is a fail-safe valve 11 of FIG. 5 in the prior art).
6 respectively), 5 is an inlet valve.

Reference numeral 6 denotes a first cylinder assembly which constitutes a first hydraulic pressure absorber, and defines a cylinder 6a and a hydraulic pressure absorbing chamber communicating with the tandem master cylinder 2 via the inlet valve 5 in the cylinder 6a. For this purpose, a piston 6b slidably provided in the cylinder 6a and a reaction spring 6c (biasing means) for biasing the piston 6b to the side where the hydraulic pressure absorbing chamber is reduced. The cylinder 6a and the piston 6b
A seal (not shown) is interposed between them. Reference numeral 7 denotes a second cylinder assembly, a piston slidably provided in the cylinder 7a for defining the cylinder 7a and a hydraulic pressure absorbing chamber communicating with the tandem master cylinder 2 via the inlet valve 5 in the cylinder. 7b and a reaction force spring 7c (biasing means) for biasing the piston 7b toward the side for reducing the hydraulic pressure absorbing chamber.
A stopper bolt 7d (restriction member) variably provided in the movement space of the piston 7b on the opposite side of the hydraulic pressure absorption chamber, and a nut 7e for adjusting the protrusion amount of the stopper bolt 7d. The cylinder 7a and the piston 7
A seal (not shown) is interposed between b. Numeral 8 denotes a hydraulic pressure sensor which detects a hydraulic pressure generated in the tandem master cylinder 2 and converts it into an electronic control unit (not shown in FIG. (Corresponding to the electronic control unit 112).

Here, the first cylinder assembly 6 is adjusted to have a reaction force characteristic indicated by a line 60 in FIG.
The second cylinder assembly 7 is adjusted so as to have a reaction force characteristic indicated by a broken line 70 in FIG. That is, the amount of liquid absorbed by the stroke of the piston 6b based on the constant hydraulic pressure rise is the same as the piston 7 based on the constant hydraulic pressure rise.
It is adjusted to be smaller than the liquid absorption amount due to the stroke b. The reason why the folding line 70 becomes a horizontal straight line from the straight line rising to the right at the folding point g is because the piston 7b hits the stopper bolt 7d when the pedal stroke at the folding point g is reached, and the piston 7b does not stroke any more. It is.

In the present embodiment, the first cylinder assembly 6
In order to make the reaction force characteristics of the first cylinder assembly 6 and the second cylinder assembly 7 as shown in FIG.
It has a small diameter. According to this configuration, the pressure receiving area of the piston 6b is smaller than the pressure receiving area of the piston 7b, and the hydraulic pressure applied to the piston 6b can be reduced.
Even if the reaction force spring 6c has a small spring force, the first cylinder assembly can realize a characteristic that the liquid absorption amount is small with respect to a constant increase in the liquid pressure.

In the brake stroke simulator apparatus thus constructed, when a brake lamp switch (not shown) detects the driver's operation of the brake pedal, the pipes 3 and 4 are closed by a fail-safe valve. At the same time as the shutoff, the inlet valve 5 opens and the primary side pipe 2 of the tandem master cylinder 2 is opened.
a and the first cylinder assembly 6 and the second cylinder assembly 7
Is connected. Accordingly, the hydraulic pressure generated on the primary side of the tandem master cylinder 2 applies the reaction force spring 6c and the reaction force spring 7c to the piston 6b in the first cylinder assembly 6 and the piston 7b in the second cylinder assembly 7.
It acts as a force to compress c. At this time, a reaction force is generated by the contracted reaction force spring 6c and the reaction force spring 7c, and the reaction force gives a driver who operates the brake pedal 1 an operation feeling of stepping on the brake pedal 1.

Further, when the driver continues to operate the brake pedal 1, the piston 7b is pressed against the tip of the stopper bolt 7d and does not move any further, so that only the piston 6b strokes and only the reaction force spring 6c is compressed. As a result, the operational feeling (stepping response) of the brake pedal 1 changes.

Here, the relationship between the operation amount of the brake pedal 1 and the reaction force (operation feeling) is as shown by a broken line 100 in FIG. The fold line 100 is a reaction force characteristic of a configuration in which both the first cylinder assembly 6 and the second cylinder assembly 7 are connected, that is, this is a combination of the fold line 60 and the fold line 70.

When the driver operates the brake pedal 1,
Until the operation amount reaches the break point position f, that is, until the piston 7b hits the stopper 7d, both the piston 6b having a small liquid absorption amount and the piston 7b having a large liquid absorption amount are stroked. Although the liquid absorption amount is large and the operation feeling of the reaction force is relatively low, after the operation amount exceeds the break point position f, that is, after the piston 7b hits the stopper bolt 7d, the liquid absorption amount is increased. Since only the small piston 6b strokes, the liquid absorption amount with respect to the pedal stroke is small, and the operation feeling of a relatively high reaction force is obtained.

Here, when the length of the stopper bolt 7d protruding into the cylinder 7a is reduced by rotating the nut 7e, the position where the piston 7b contacts the stopper 7d moves to the back, and only the second cylinder assembly 7 is moved. In the case of the connected configuration, the fold line 70 changes like a fold line 70 ′, and the fold line 100 which is the sum of the fold line 60 and the fold line 70 changes like a fold line 100 ′ which is the sum of the fold line 60 and the fold line 70 ′. The folding point position f in FIG. 2 moves to the folding point position f ′, and the operational feeling of the brake pedal 1 changes.

Next, a second embodiment of the present invention will be described with reference to FIGS. Note that FIG.
The first cylinder assembly 6 and the second cylinder assembly 7 are substantially equivalent to each other. As shown in FIG. 3, the cylinder assembly 29 of the present embodiment includes a stepped cylinder 30.
A substantially cylindrical large-diameter piston 32 (large pressure receiving area) is slidably fitted in a small-diameter bore 31 of the (cylinder).
A spring receiver 34 is movably guided in the large diameter bore 33. A small-diameter piston 36 (small pressure-receiving area) is slidably fitted in a cylinder portion 35 formed in the large-diameter piston 32. In the figure, reference numerals 37 and 38 denote piston seals. A pressure chamber 39 formed in the small-diameter bore 31 by the large-diameter piston 32 and the small-diameter piston 36 communicates with the above-described master cylinder (not shown) through the inlet / outlet port 40. A large-diameter first spring 43 (biasing means) is interposed between the spring receiver 34 and a spring receiver 42 at the bottom of the large-diameter bore 33.
The large-diameter piston 32 is pressed against the bottom of the small-diameter bore 31 by causing the cylindrical contact portion 44 formed at the distal end of the large-diameter piston 32 to abut against the rear end of the large-diameter piston 32 due to the spring force.
A small-diameter second spring 45 (biasing means) is interposed between the spring receiver 34 and the small-diameter piston 36, and the tip of the small-diameter piston 36 is formed by the spring force of the second spring 45. 35 is pressed against a step 46 formed at the opening on the distal end side.

At the bottom of the large diameter bore 33, a stopper 49 (a regulating member) which abuts against the spring receiver 34 and regulates its stroke projects, and the amount of projection is provided outside the cylinder assembly 29. The adjustment can be made by the electric device 50.

The spring force of the first spring 43 and the second spring 45 is such that when the pressure of the brake fluid in the pressure chamber 39 increases,
First, the spring receiver 34 strokes to compress the first spring 43 by the sum of the hydraulic pressures (thrusts) received by the large-diameter piston 32 and the small-diameter piston 36, and the spring receiver 34 comes into contact with the stopper 49. During this time, the hydraulic pressure (thrust) received by the small-diameter piston 36 is set so as to compress the second spring 45 and make a stroke.

That is, the large-diameter piston 3 of the present embodiment
2 and the small-diameter piston 36 substantially correspond to the piston 7b and the piston 6b of the first embodiment, respectively, and the first spring 43 and the second spring 45 of the present embodiment respectively correspond to the counterparts of the first embodiment. They substantially correspond to the force spring 7c and the reaction force spring 6c. With this configuration, as in the first embodiment, even if the second spring 45 has a small spring force, the liquid absorber composed of the small-diameter piston 36 and the cylinder portion 35
The characteristic that the liquid absorption amount is small with respect to a constant increase in the liquid pressure can be realized.

The operation of the embodiment constructed as described above will now be described.

The relationship between the hydraulic pressure (= reaction force) introduced into the pressure chamber 39 from the inlet / outlet port 40 of the cylinder assembly 29 and the amount of introduced liquid (ie, the amount of operation of the pedal) will be described with reference to FIG. explain.

By operating the brake pedal, the brake fluid discharged from the master cylinder is introduced from the inlet / outlet port 40 into the pressure chamber 39, and the large-diameter piston 32 and the small-diameter piston 36 are stroked according to the hydraulic pressure. The thrust of the large-diameter piston 32 and the thrust of the small-diameter piston 36 are transmitted to the spring receiver 34 via the spring receiver 45, and the pressure chamber 3
9 reaches the starting hydraulic pressure P1, the total thrust of the large-diameter and small-diameter pistons 32 and 36 reaches the set load of the first spring 43 and compresses the first spring 43, and the large-diameter and small-diameter pistons 32 , 36 and the spring receiver 34 make a stroke (section ab). During this time, the thrust generated by the hydraulic pressure acting on the pressure receiving area of the small diameter piston 36 compresses the second spring 45, and the small diameter piston 36 moves relatively to the large diameter piston 32.

When the hydraulic pressure in the pressure chamber 39 reaches the hydraulic pressure P2,
The spring receiver 34 comes into contact with the stopper portion 49, and the stroke of the large-diameter piston 32 is regulated. As the hydraulic pressure in the pressure chamber 39 increases, the second spring 45 is continuously compressed by the thrust of the small-diameter piston 36. And small diameter piston 4
Only 5 strokes (section bc).

Thus, in the section ab corresponding to the initial stage of the stroke of the brake pedal, the total pressure receiving area of the large-diameter and small-diameter pistons 32 and 36 (large pressure-receiving area).
The first spring 43 is driven by the thrust generated by the hydraulic pressure acting on the first spring 43.
Therefore, the starting hydraulic pressure can be sufficiently reduced, and the operation of the pedal stroke can be started up smoothly.

Thereafter, in the section bc, the second spring 45 is compressed only by the thrust generated by the hydraulic pressure acting only on the small-diameter piston 36 (small pressure-receiving area). It is possible to obtain a good brake operation feeling by appropriately increasing the force.

Here, the stopper 49 is operated by a control device (not shown) to remotely drive the electric device 50 by operating an adjustment switch in the driver's seat (not shown) according to the driver's preference, the driving situation of the vehicle, and the like. As a result, the amount of protrusion into the large diameter bore 33 changes. Stopper part 49
The position at which the spring receiver 34 contacts the stopper 49 (that is, the position at the point b in FIG. 4) changes, and the operational feeling of the brake pedal changes.

For example, when the amount of protrusion of the stopper portion 49 decreases, the position of the point b in FIG.
Is extended to the section ab ′ with the same slope, and the section bc starts from b ′ and has a section b′− having the same slope as the section bc.
A graph of c 'is obtained (see the dotted line in FIG. 4).

The electric device 50 for changing the amount of protrusion of the stopper portion 49 includes, but is not limited to, an assembly of a motor and a ball screw, a motor and a ball ramp mechanism, a linear actuator, and the like.

The configuration of the first embodiment or the second embodiment of the present invention may be connected to both the primary side pipe and the secondary side pipe of the tandem master cylinder. Further, in the first embodiment, a tandem master cylinder is used, but the invention is not limited to this.
A single master cylinder may be used. In the first embodiment, the inlet valve 5 is provided, but may not be provided.

In the first embodiment, the cylinder assembly with the stopper and the cylinder assembly without the stopper are each one combination. However, the present invention is not limited to this, and one or more cylinders with the stopper are provided. A plurality of cylinder assemblies without stoppers may be provided for the assembly, and a plurality of cylinder assemblies with stoppers may be provided for one or more cylinder assemblies without stopper. A stopper may be provided on the assembly.

In the first and second embodiments, the pedal is used as the brake operator. However, the present invention is not limited to this, and the lever may be used as in a brake device of a motorcycle. Alternatively, a steering wheel may be used as in a brake device of a railway vehicle, or another operation element may be used.

[0033]

As described above, according to the present invention, a hydraulic pressure control valve provided between a wheel cylinder and a hydraulic pressure source for supplying high-pressure brake fluid is drive-controlled to provide a brake operator. A brake stroke simulator device that is provided in a brake device that generates a braking force in accordance with the operation force of the wheel cylinder in the wheel cylinder, and that applies a stroke in accordance with the operation force to the brake operator, wherein the brake stroke simulator device includes: A hydraulic pressure conversion device that converts the operating force of the brake operator to hydraulic pressure and outputs the hydraulic pressure;
A plurality of hydraulic pressure absorbers for absorbing the output hydraulic pressure from the hydraulic pressure conversion device, wherein each of the hydraulic pressure absorbers has a hydraulic pressure absorption chamber communicating with the hydraulic pressure conversion device in a cylinder. A piston slidably provided in the cylinder to define the piston, and biasing means for biasing the piston toward a side for reducing the hydraulic pressure absorbing chamber. The sliding range of at least one of the hydraulic absorbers is variably regulated by the hydraulic pressure supplied from the hydraulic pressure converter, against the urging force of the urging means of the piston of the hydraulic absorber. By providing the restricting means, it is possible to easily change the operation feeling of the brake operator without changing parts.

[Brief description of the drawings]

FIG. 1 is a configuration of a brake stroke simulator device according to a first embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a brake pedal stroke and a reaction force (operating feeling) according to the first embodiment of the brake stroke simulator device of the present invention.

FIG. 3 is a sectional view showing a structure of a composite cylinder assembly according to a second embodiment of the brake stroke simulator device of the present invention.

FIG. 4 is a graph showing a relationship between a brake pedal stroke and a reaction force (operating feeling) according to a second embodiment of the brake stroke simulator device of the present invention.

FIG. 5 is a configuration example of a brake device using a brake stroke simulator device according to a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 brake pedal (operator) 2 tandem master cylinder 5 inlet valve 6 first cylinder assembly 6 a cylinder 6 b piston 6 c reaction spring (biasing means) 7 second cylinder assembly 7 a cylinder 7 b piston 7 c reaction spring (biasing) Means) 7d Stopper Bolt 7e Nut 29 Cylinder Assembly 30 Stepped Cylinder (Cylinder) 31 Small Diameter Bore 32 Large Diameter Piston 33 Large Diameter Bore 34 Spring Receiver 35 Cylinder 36 Small Diameter Piston 39 Pressure Chamber 40 Entry / Exit Port 42 Spring Reception 43 1 spring 45 second spring 49 stopper 50 electric device

Continued on the front page F term (reference) 3D046 BB03 BB17 CC02 CC04 EE01 LL05 LL23 LL41 LL43 LL51 LL54 3D047 BB11 CC07 FF15 FF22 GG03 KK03

Claims (1)

[Claims] A drive control unit controls a hydraulic pressure control valve provided between a wheel cylinder and a hydraulic pressure source for supplying high-pressure brake fluid, and applies a brake force according to an operation force of a brake operation element to the wheel. A brake stroke simulator device provided in a brake device to be generated in a cylinder and imparting a stroke according to the operation force to the brake pedal or lever, wherein the brake stroke simulator device converts the operation force of the brake operator to a hydraulic pressure. A hydraulic pressure converter for converting and outputting, and a plurality of hydraulic pressure absorbers for absorbing output hydraulic pressure from the hydraulic pressure converter, wherein each of the hydraulic pressure absorbers is A piston slidably provided in the cylinder for defining a hydraulic absorption chamber communicating with the cylinder in the cylinder, and reducing the hydraulic absorption chamber. Said piston is composed of a biasing means for biasing the, at least one fluid pressure absorber of the plurality of hydraulic absorber to,
It is characterized in that a regulating means for variably regulating a sliding range of the hydraulic pressure absorber against the urging force of the urging means of the piston by the hydraulic pressure supplied from the hydraulic pressure converter is provided. Brake stroke simulator device.