Pump device

Patent metadata

Field	Value
Publication number	US-10087917-B2
Application number	US-201314402726-A
Country	US
Kind code	B2
Filing date	May 20, 2013
Priority date	May 22, 2012
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

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.

First claim

The invention claimed is:

1. 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.

2. The pump device as claimed in claim 1 , wherein:
the pump has a delivery valve that allows only a flow of the brake fluid in a discharge direction of the pump, and
the pulsation reduction unit is provided at a downstream side of the delivery valve.

3. The pump device as claimed in claim 1 , wherein:
the pulsation reduction unit has a third orifice, which is provided parallel to the second orifice and through which, when the flow amount becomes a second predetermined flow amount that is greater than the predetermined flow amount, the brake fluid passes.

4. 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.

5. The pulsation reduction unit for the pump device as claimed in claim 4 , wherein:
the pump has a delivery valve that allows only a flow of the brake fluid in a discharge direction of the pump, and
the pulsation reduction unit is provided at a downstream side of the delivery valve.

6. 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.

7. The pump device as claimed in claim 6 , wherein:
the first fixed orifice and the second fixed orifice are arranged parallel to each other with reference to a flow of the brake fluid.

8. The pump device as claimed in claim 7 , wherein:
the pump has a delivery valve that allows only a flow of the brake fluid in a discharge direction of the pump, and
the space is provided at a downstream side of the delivery valve.

9. The pump device as claimed in claim 8 , wherein:
the dividing plate has a third fixed orifice, which is parallel to the second fixed orifice and through which, when the discharge flow amount becomes a second predetermined flow amount that is greater than the predetermined flow amount, the brake fluid passes.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Saito Masayuki
• Nakazawa Chiharu
• Misunou Masaki

Classifications

• B60T17/02

  Arrangements of pumps or compressors, or control devices therefor · CPC title

• B60T8/5037

  closed systems · CPC title

• F04C2/344

  with vanes reciprocating with respect to the inner member · CPC title

• F04C2/10

  of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member · CPC title

• F04B11/00

  Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation · CPC title