Pulsation damping device of hydraulic brake system

Patent metadata

Field	Value
Publication number	US-10926747-B2
Application number	US-201916352815-A
Country	US
Kind code	B2
Filing date	Mar 13, 2019
Priority date	Mar 14, 2018
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Disclosed is a pulsation damping device of a hydraulic brake system including a first damper having a first damping chamber whose volume is varied by the hydraulic pressure of the brake oil, and a second damper having a second damping chamber whose volume is varied by the hydraulic pressure of the brake oil, wherein the volume change rate of the first damping chamber relative to the hydraulic pressure of the brake oil is provided to be larger than the volume change rate of the second damping chamber, and the hydraulic pressure of the corresponding brake oil in the first damping chamber when reaching the maximum variable volume is provided to be smaller than the hydraulic pressure of the corresponding brake oil in the second damping chamber when reaching the maximum variable volume.

First claim

What is claimed is:

1. A pulsation damping device of a hydraulic brake system which attenuates a pressure pulsation of brake oil discharged from a pump, comprising:
a first damper having a first damping chamber whose volume is varied by the hydraulic pressure of the brake oil; and
a second damper having a second damping chamber whose volume is varied by the hydraulic pressure of the brake oil,
wherein a volume change rate of the first damping chamber relative to the hydraulic pressure of the brake oil is provided to be larger than a volume change rate of the second damping chamber, and
the hydraulic pressure of the corresponding brake oil in the first damping chamber when reaching a maximum variable volume of the first damping chamber is provided to be smaller than the hydraulic pressure of the corresponding brake oil in the second damping chamber when reaching a maximum variable volume of the second damping chamber.

2. The pulsation damping device according to claim 1 , wherein:
the first damper further includes a first damping member having the first damping chamber formed therein, a first stopper member coupled to the first damping member and having a first flow passage communicating a hydraulic passage through which the brake oil flows to the first damping chamber, and a first sleeve surrounding the first damping member and coupled to the first stopper member; and
the second damper further includes a second damping member having the second damping chamber formed therein, a second stopper member coupled to the second damping member and having a second flow passage communicating a hydraulic passage through which the brake oil flows to the second damping chamber, and a second sleeve surrounding the second damping member and coupled to the second stopper member.

3. The pulsation damping device according to claim 2 , wherein:
at least one first concave-convex portion is provided on an outer circumferential surface of the first damping member;
at least one second concave-convex portion is provided on an outer circumferential surface of the second damping member;
a first auxiliary damping chamber is formed between the first concave-convex portion and the first sleeve; and
a second auxiliary damping chamber is formed between the second concave-convex portion and the second sleeve.

4. The pulsation damping device according to claim 3 , wherein:
the first damping member includes a first coupling portion formed in a hollow shape on an inlet/outlet side of the first damping chamber and coupled to the first stopper member;
the first stopper member includes a first insertion portion coupled to an inner circumferential surface of the first coupling portion, and a first cap portion closing a first bore on which the first sleeve is mounted and coupled to an inner circumferential surface of the first sleeve;
the second damping member includes a second coupling portion formed in a hollow shape on an inlet/outlet side of the second damping chamber and coupled to the second stopper member; and
the second stopper member includes a second insertion portion coupled to an inner circumferential surface of the second coupling portion and a second cap portion coupled to an inner circumferential surface of the second sleeve.

5. The pulsation damping device according to claim 4 , wherein:
the first stopper member further includes a first coupling groove formed to be recessed on an outer circumferential surface of the first insertion portion;
the first damping member further includes a first sealing portion provided on the first coupling portion and entering and seated in the first coupling groove;
the second stopper member further includes a second coupling groove formed to be recessed on an outer circumferential surface of the second insertion portion; and
the second damping member further includes a second sealing portion provided on the second coupling portion and entering and seated in the second coupling groove.

6. The pulsation damping device according to claim 1 , wherein:
a variable volume amount of the first damping chamber is provided to be larger than a variable volume amount of the second damping chamber.

7. The pulsation damping device according to claim 1 , wherein:
the first damper includes a first damping member having the first damping chamber formed therein;
the second damper includes a second damping member having the second damping chamber formed therein; and
the thickness between an outer circumferential surface of the first damping member and an inner circumferential surface of the first damping chamber is provided to be smaller than the thickness between an outer circumferential surface of the second damping member and an inner circumferential surface of the second damping chamber.

8. The pulsation damping device according to claim 1 , wherein:
the first damper includes a first damping member having the first damping chamber formed therein;
the second damper includes a second damping member having the second damping chamber formed therein; and
the ratio of the volume of the first damping chamber to the volume of the first damping member is provided to be greater than the ratio of the volume of the second damping chamber to the volume of the second damping member.

9. The pulsation damping device according to claim 1 , wherein:
the first damper includes a first damping member having the first damping chamber formed therein;
the second damper includes a second damping member having the second damping chamber formed therein; and
the elastic modulus of the first damping member is provided to be smaller than the elastic modulus of the second damping member.

10. The pulsation damping device according to claim 1 , wherein:
the first damper and the second damper are arranged in series at a rear end portion of the pump.

11. The pulsation damping device according to claim 1 , wherein:
the first damper and the second damper are arranged in parallel at a rear end portion of the pump.

12. A pulsation damping device of a hydraulic brake system which attenuates a pressure pulsation of brake oil discharged from a pump, comprising:
a first damper having a first damping chamber whose volume is varied by the hydraulic pressure of the brake oil; and
a second damper having a second damping chamber whose volume is varied by the hydraulic pressure of the brake oil,
wherein a volume change rate of the first damping chamber relative to the hydraulic pressure of the brake oil is provided to be larger than a volume change rate of the second damping chamber, and
the hydraulic pressure of the corresponding brake oil in the first damping chamber when reaching a maximum variable volume of the first damping chamber is provided to be smaller than the hydraulic pressure of the corresponding brake oil in the second damping chamber when reaching a maximum variable volume of the second damping chamber,
wherein:
at least one of the first damper and the second damper further includes a sealing portion for preventing leakage of the brake oil entering the damping chamber; and
the sealing portion includes protrusions that are urged in a direction to seal the damping chamber as the hydraulic pressure of the brake oil entering the damping chamber increases.

13. The pulsation damping device according to claim 12 , wherein:
the first damper further includes a first damping member having the first damping chamber formed therein, a first stopper member coupled to the first damping member and having a first flow passage communicating a hydraulic passage through which the brake oil flows to the first damping chamber, and a first sleeve surrounding the firs

Assignees

• Mando Corp

Inventors

• Song Min Geun
• Baek Heeseung

Classifications

• B60T8/4872

  pump-back systems · CPC title

• B60T8/42

  having expanding chambers for controlling pressure {, i.e. closed systems} · CPC title

• B60T8/4068 Primary

  the additional fluid circuit comprising means for attenuating pressure pulsations · CPC title

• B60T17/00

  Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features (air compressors per se F04) · CPC title

• B60T8/344

  Hydraulic systems · CPC title