JPH0589137U - Stroke accumulator - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain the same reaction force characteristics as when using a diaphragm with a nonstandard thickness by using a metal diaphragm with a standard thickness. [Structure] A pressure accumulating chamber 43 communicating with the output port 3 of the master cylinder 2 operated by the brake pedal 1 is formed in the accumulator body 35, and a plurality of diaphragms 40 ₁ and 40 ₂ are stretched to face the pressure accumulating chamber 43. However, the thicknesses of these diaphragms 40 ₁ and 40 ₂ are made different from each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a stroke accumulator for applying an operation reaction force corresponding to an operation amount to an operator in a hydraulic booster, and particularly to a hydraulic pressure generator operated by the operator and an output port in an accumulator main body. The present invention relates to an improvement in which hydraulic pressure generated in the pressure accumulating chamber is communicated to the operator as an operation reaction force.

[0002]

[Prior Art]

 Such a stroke accumulator is already known, for example, as disclosed in Japanese Patent Laid-Open No. 1-141157.

As shown in FIG. 6, the reaction force characteristic of such a stroke accumulator is such that the reaction force generated with respect to the amount of oil supplied to the pressure accumulator desirably changes in a quadratic curve. With such characteristics, an accurate operation reaction force can be obtained even in an operation stroke with a small number of operators, which is effective in obtaining a good operation feeling.

Therefore, in order to obtain the reaction force characteristics as described above, an accumulator body and a metal diaphragm that has an outer peripheral edge fixed to the accumulator body and divides the body into a pressure accumulating chamber and an air chamber are provided. Another stroke accumulator has already been proposed (see Japanese Patent Application No. 3-41780).

[0005]

[Problems to be solved by the device]

 However, in the market, there are only thin plates used for metal diaphragms, such as steel plates, that have a thickness specified by the standard, so when the characteristics of a metal diaphragm with a nonstandard thickness are required. Unless the special diaphragm is used, the above proposal cannot meet the requirement.

The present invention has been made in view of such circumstances, and has characteristics equivalent to those obtained by using a metal diaphragm having a thickness defined by a standard and using a metal diaphragm having a nonstandard thickness. It is an object to provide the stroke accumulator that can be obtained freely.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is characterized in that a plurality of metal diaphragms having different thicknesses are stretched on the accumulator body so as to face the accumulator chamber.

A steel plate, an Al alloy plate, a titanium alloy plate, or the like is suitable as a material for the metal diaphragm.

[0009]

【Example】

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

FIG. 1 is a partial vertical cross-sectional side view of a vehicle booster braking device to which the present invention is applied. In the figure, an output port 3 of a known master cylinder 2 (hydraulic pressure generator) operated by a brake pedal 1 (operator) is connected to an input port 5 of a booster cylinder 4 via a hydraulic hose 6, and a booster cylinder. The output port 7 of No. 4 is connected to the hydraulically operated portion of the wheel brake 8 via a hydraulic hose 9.

The booster cylinder 4 includes a booster body 10 and a booster piston 12 that slides in a cylinder hole 11 of the booster body 10. At the rear end of the booster piston 12, a drive for driving the booster piston 12 forward and backward. The device 13 is connected.

The booster piston 12 is configured by integrally connecting a pair of front and rear piston portions 12a and 12b arranged at a constant interval by a rod portion 12c. The front piston portion 12a defines an operating hydraulic chamber 14 with the front end wall of the booster body 10, and the output port 7 is connected to the operating hydraulic chamber 14. A return spring 15 that biases the booster piston 12 in the backward direction is housed in the hydraulic pressure chamber 14.

The front and rear piston portions 12 a and 12 b define a relay hydraulic chamber 16 therebetween. The input port 5 and an accumulator port 17 located behind the input port 5 are provided on the side wall of the booster body 10. The input port 5 opens to the working hydraulic chamber 14 when the booster piston 12 is located at the backward limit. When the booster piston 12 moves forward from the rearward end, the opening to the relay hydraulic chamber 16 is switched. Further, the accumulator port 17 is always open to the relay hydraulic chamber 16, and the stroke accumulator 19 of the present invention is connected to this through the hydraulic hose 18.

A control device 20 composed of a computer for controlling the operation of the drive device 13 is connected to the drive device 13. The control device 20 is provided in an operation system of the master cylinder 2 and has a pedaling force sensor 21 and a wheel lock proximity sensor. 22 and output signals from the wheel spin sensor 23 and the like are input.

FIG. 2 is a vertical sectional side view of the drive unit 13. In the figure, the drive device 13 includes an electric motor 25 and an operating shaft 28 screwed to a rotor 26 of the electric motor 25 via a ball screw 27. The housing 29 of the electric motor 25 is bolted to the rear end of the booster body 10, and the front end surface of the housing 29 receives the booster piston 12 to regulate the backward movement limit thereof. The operating shaft 28 has a front end projecting forward of the housing 29 to push the booster piston 12. The actuating shaft 28 has a rear end projecting into a spring chamber 30 formed in the rear portion of the housing 29, and a return spring 32 for biasing a stopper plate 31 fixed to the rear end rearward is accommodated in the spring chamber 30. To be done. The stopper plate 31 contacts the rear wall of the spring chamber 30 to regulate the backward movement limit of the operating shaft 28. The stopper plate 31 has a protrusion 31a on its outer periphery, and the protrusion 31a is slidably engaged with a key groove 33 formed on the inner peripheral surface of the spring chamber 30. In this way, the operating shaft 28 is prevented from rotating and can move in the axial direction, and can be moved forward / backward by the forward / reverse rotation of the rotor 26.

3 and 4 are a vertical sectional side view and a partially cutaway plan view of the stroke accumulator 19, respectively. In these figures, the accumulator body 35 of the stroke accumulator 19 has a circular recess 36 on both upper and lower end surfaces.₁, 36₂A core plate 37 having a₁, 36₂It is composed of a pair of end plates 39, 39 which are connected to the upper and lower end surfaces of the core plate 37 by several bolts 38 so as to close the open end of the. Each recess 36₁ , 36₂The metal diaphragm 40₁, 40₂And these diaphragms 40 ₁ , 40₂Restriction plate 41 for clamping the outer peripheral portion of the core plate 37 to the core plate 37.₁, 41₂And are housed.

Accumulation chambers 43, 43 facing the inner surfaces of the diaphragms 40 ₁ , 40 ₂ are formed as recesses on the upper and lower surfaces of the core plate 37, respectively, and sealing members 42, 42 surrounding the pressure accumulation chambers 43, 43 are formed. Is interposed between the core plate 37 and the diaphragms 40 ₁ and 40 ₂ . The upper and lower pressure accumulating chambers 43, 43 communicate with the hydraulic hose 18 through the through hole 45 of the core plate 37. After all, both pressure accumulating chambers 43, 43 are always in communication with the relay hydraulic chamber 16 via the hydraulic hose 18.

Further, air chambers 44 ₁ and 44 ₂ facing the outer side surfaces of the diaphragms 40 ₁ and 40 ₂ are formed as concave portions on the inner side surfaces of the deflection restricting plates 41 ₁ and 41 ₂ , respectively.

In this embodiment, therefore, one diaphragm 40 ₁ is stamped from a steel plate having a thickness of 1.4 mm, and the other diaphragm 40 ₂ is stamped from a steel plate having a thickness of 1.2 mm. The spring rates of the diaphragms 40 ₁ and 40 ₂ are larger as the thickness is larger. The maximum deflection regulation amount of the diaphragms 40 ₁ and 40 ₂ by the deflection regulation plates 41 ₁ and 41 ₂ is arbitrarily set according to the required characteristics.

Next, the operation of this embodiment will be described.

In the rest state of the master cylinder 2 and the booster cylinder 4, as shown in FIG. 1, the input port 5 of the booster cylinder 4 is open to the working hydraulic chamber 14. Therefore, when the hydraulic oil expands or contracts due to the temperature change, the hydraulic oil flows between the hydraulic pressure chamber 14 and the master cylinder 2.

Now, when the master pedal 2 is operated by depressing the brake pedal 1 to perform braking, the pedal force sensor 21 detects the pedal force applied to the brake pedal 1 and outputs a pedal force signal corresponding to it. The control device 20 having received the signal first drives the electric motor 25 forward by a predetermined angle regardless of the strength of the pedaling force signal, and advances the booster piston 12 by a predetermined amount by the operating shaft 28 as shown in FIG. The port 7 is opened to the relay hydraulic chamber 16 side, and then the electric motor 25 is normally driven according to the strength of the pedaling force signal. When the booster piston 12 is pushed forward by the forward movement of the operating shaft 28 by the forward drive of the electric motor 25, hydraulic pressure corresponding to the forward movement amount is generated in the operating hydraulic chamber 14 and this is output to the output port 7. Is transmitted to the wheel brake 8. In this way, the wheel break 8 can exert a braking force according to the pedaling force applied to the brake pedal 1.

On the other hand, when the opening of the input port 5 to the relay hydraulic chamber 16 is switched, the master cylinder 2 communicates with the pressure accumulating chambers 43, 43 of the stroke accumulator 19 via the relay hydraulic chamber 16. Accordingly, the hydraulic oil is supplied from the master cylinder 2 to the pressure accumulating chambers 43, 43 through the relay hydraulic chamber 16 in response to the depression of the brake pedal 1, and the diaphragms 40 ₁ , 40 ₂ move to the pressure accumulating chambers 43, 43 in accordance with the increase in the amount of the supplied oil. Bending occurs so as to expand the volumes of 43 and 43. In other words, the diaphragms 40 ₁ and 40 ₂ are pulled in all directions, and the repulsive force generates hydraulic pressure in the pressure accumulating chambers 43 and 43, and this hydraulic pressure is transmitted to the master cylinder 2 as a reaction force, which is transmitted to the brake pedal 1. From this, the pilot can get a break feeling. Incidentally, FIG. 6 shows the relationship between the reaction force characteristics of the diaphragm 40 _1, 4 0 ₂ in the thickness and the stroke accumulators 19, A is when a 1.4mm both the thickness of both diaphragms 40 _1, 40 ₂ Characteristics, B is the characteristics when the thicknesses of both diaphragms 40 ₁ and 40 ₂ are 1.2 mm, C is the characteristics when the thicknesses of both diaphragms 40 ₁ and 40 ₂ are both 1.0 mm, and D is the The characteristic of the embodiment of the invention, that is, the characteristic when the thickness of _one diaphragm 40 ₁ is 1.4 mm and the thickness of the other diaphragm 40 ₂ is 1.2 mm is shown.

By the way, the thickness of the steel plate which is the material of the diaphragm is standardly defined as 1.0 mm, 1.2 mm, 1.4 mm.

As is clear from the figure, each of the characteristics A to D shows a quadratic curve characteristic, but the characteristic D of the embodiment of the present invention is obtained with the two diaphragms of the same thickness existing in the standard. It turns out that it is something that cannot be done.

By changing the thicknesses of the _two diaphragms 40 ₁ and 40 ₂ in this way, the reaction force characteristics of the stroke accumulator 19 can be set freely, and the brake pedal 1 Can provide a desired operation reaction force and operation stroke regardless of the stroke of the booster piston 12.

In this case, according to experiments, it was effective to obtain a good braking feeling when the thickness of the thin diaphragm 40 ₁ was 55 to 90% of the thickness of the thick diaphragm 40 ₂ .

When the wheels are about to lock during braking as described above, the lock proximity sensor 22 outputs a lock proximity signal, and the control device 20 receiving this signal rotates the electric motor 25 in the backward and backward directions, Thus, the working hydraulic chamber 14 is depressurized, so that the braking force of the wheel brake 8 can be reduced and the locked state of the wheels can be avoided in advance.

Further, when the master cylinder 2 and the booster cylinder 4 are in a resting state and the driving wheels spin due to the excessive driving force or the low friction coefficient of the road surface, the spin sensor 23 sends a spin signal to the control device 20. Therefore, the control device 20 drives the electric motor 25 in the normal direction to move the booster piston 12 forward by the operating shaft 28, which raises the working hydraulic chamber 14 and activates the wheel brake 8 to spin the driving wheel. Suppress.

Next, a case where the electric motor 25 becomes inoperable due to a failure such as disconnection will be described. In such a case, the operating shaft 28 is continuously held in the retracted limit by the return spring 32, so that the booster piston 12 is also retained in the retracted limit by the return spring 15 and the input port 5 is continuously opened to the operating hydraulic chamber 14. become. If the master cylinder 2 is operated at such a time, the output hydraulic pressure is transmitted to the operating hydraulic chamber 14 via the input port 5, so that the chamber 14 can be boosted to operate the wheel brakes 8. . Therefore, fail safe is achieved. In this case, since the booster piston 12 blocks the master cylinder 2 and the relay hydraulic chamber 16, the hydraulic fluid sent from the master cylinder 2 is not sent to the stroke accumulator 19, and the hydraulic chamber is not operated. 14 are supplied. Therefore, there is no liquid loss, and an unnecessary increase in the amount of depression of the brake pedal can be suppressed.

Although one stroke accumulator 19 is used in the above embodiment, a plurality of stroke accumulators 19 can be connected in parallel, and in that case, the thickness of the diaphragm can be reduced between the stroke accumulators. It may be different.

[0032]

[Effect of the device]

 As described above, according to the present invention, a plurality of metal diaphragms having different thicknesses are stretched on the accumulator body so as to face the accumulator chamber. This makes it possible to obtain reaction force characteristics equivalent to those when a non-standard diaphragm is used, and therefore it is possible to meet various required characteristics at a low cost.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view of a booster system for a vehicle using a stroke accumulator of the present invention.

FIG. 2 is a partially longitudinal side view of the drive device in FIG.

FIG. 3 is a vertical sectional side view of the stroke accumulator in FIG.

FIG. 4 is a partially cutaway plan view of FIG.

5 is an explanatory view of the operation of the booster cylinder in FIG.

FIG. 6 is a reaction force characteristic diagram of the stroke accumulator.

[Explanation of symbols]

1 Brake pedal as an operator 2 Master cylinder as a hydraulic pressure generator 3 Output port 19 Stroke accumulator 35 Accumulator body 40 ₁ , 40 ₂ Diaphragm 43 Accumulation chamber

Claims (2)

[Scope of utility model registration request] 1. A pressure accumulator chamber (43) in an accumulator body (35) communicates with an output port (3) of a hydraulic pressure generator (2) operated by an operator (1).
In a stroke accumulator in which the hydraulic pressure generated in 3) is transmitted to the operator (1) as an operation reaction force, a plurality of metal diaphragms (40 ₁ , 4) having different thicknesses are used.
No. 0 ₂ ) faces the accumulator chamber (43) and is stretched on the accumulator body (35). 2. The diaphragm according to claim 1, wherein the thin thickness of the diaphragm is 55 to 9 of the thick thickness.
Stroke accumulator set to 0%.