Pump device
AssigneeHitachi Automotive Systems, Ltd.
InventorsMasayuki Saito, Chiharu Nakazawa, Masaki Misunou
Life of this patent
Estimating the term…
Abstract
An object of the present invention is to provide a pump device that is capable of improving a discharge performance. A first orifice 301 that is provided on a discharge oil passage (a pipe 12) of a pump 2 and a second orifice 302 that, when a flow amount Q becomes greater than a predetermined flow amount Q1, allows pass of brake fluid are provided.
Claims9
A pump device including a pulsation reduction unit, which reduces pulsation of brake fluid discharged from a pump, the pulsation reduction unit comprising:
- a dividing plate, movably located in a space provided on a discharge oil passage of the pump, dividing the space into an upstream side chamber and a downstream side chamber;
- a spring element configured to engage a wall portion of the space and perform a sealing function that stops leakage of the brake fluid between the upstream side chamber and the downstream side chamber through a gap located at an outer peripheral side of the dividing plate;
- a valve body provided in the upstream side chamber, defining a first chamber to which the discharge oil passage opens and a second chamber to which the discharge oil passage does not open in the upstream side chamber by closing when a flow amount of the brake fluid discharged from the pump is equal to or less than a predetermined flow amount, the valve body opening when the flow amount of the discharged brake fluid is greater than the predetermined flow amount;
- a first orifice, which is formed by penetrating the dividing plate, that opens to the first chamber;
- and
- a second orifice, which is formed by penetrating the dividing plate, that opens to the second chamber;
- wherein:
- when the flow amount of the discharged brake fluid is greater than the predetermined flow amount, the dividing plate moves forward and backward in response to a hydraulic pressure variation due to pulsation of the discharged brake fluid with the valve body open.
A pulsation reduction unit for a pump device, the pulsation reduction unit reducing pulsation of brake fluid discharged from a pump and comprising:
- a dividing plate, movably located in a space provided on a discharge oil passage of the pump, dividing the space into an upstream side chamber and a downstream side chamber;
- a spring element configured to engage a wall portion of the space and perform a sealing function that stops leakage of the brake fluid between the upstream side chamber and the downstream side chamber through a gap located at an outer peripheral side of the dividing plate;
- a valve body provided in the upstream side chamber, defining a first chamber to which the discharge oil passage opens and a second chamber to which the discharge oil passage does not open in the upstream side chamber by closing when a flow amount of the brake fluid discharged from the pump is equal to or less than a predetermined flow amount, the valve body opening when the flow amount of the discharged brake fluid is greater than the predetermined flow amount;
- a first orifice, which is formed by penetrating the dividing plate, that opens to the first chamber;
- and
- a second orifice, which is formed by penetrating the dividing plate, and which opens to the second chamber.
A pump device including a pulsation reduction unit, which reduces pulsation of brake fluid discharged from a pump, the pulsation reduction unit comprising:
- a dividing plate, movably located in a space provided on a discharge oil passage of the pump, dividing the space into an upstream side chamber and a downstream side chamber;
- a spring element configured to engage a wall portion of the space and perform a sealing function that stops leakage of the brake fluid between the upstream side chamber and the downstream side chamber through a gap located at an outer peripheral side of the dividing plate;
- a valve body provided in the upstream side chamber, defining a first chamber to which the discharge oil passage opens and a second chamber to which the discharge oil passage does not open in the upstream side chamber by closing when a flow amount of the brake fluid discharged from the pump is equal to or less than a predetermined flow amount, the valve body opening when the flow amount of the discharged brake fluid is greater than the predetermined flow amount;
- a first fixed orifice, which is formed by penetrating the dividing plate, that opens to the first chamber;
- and
- a second fixed orifice, which is formed by penetrating the dividing plate, that opens to the second chamber.
Dependencies are inferred from the claim text.