Negative pressure controller

Patent metadata

Field	Value
Publication number	US-9802594-B2
Application number	US-201615231235-A
Country	US
Kind code	B2
Filing date	Aug 8, 2016
Priority date	Sep 29, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A negative pressure controller controls a negative pressure in a vacuum chamber of a vacuum booster by controlling a negative pressure supplier connected to the vacuum chamber. The negative pressure controller includes: negative pressure sensors each configured to detect the negative pressure in the vacuum chamber; and a negative-pressure-supplier controller configured to actuate the negative pressure supplier when one of output values of the negative pressure sensors which is nearest to an atmospheric pressure among the output values becomes nearer to an atmospheric pressure than a first threshold value. The negative-pressure-supplier controller is configured to stop the negative pressure supplier when at least two output values of the output values of the negative pressure sensors become nearer to a vacuum than a second threshold value.

First claim

What is claimed is:

1. A negative pressure controller configured to control a negative pressure in a vacuum chamber of a vacuum booster by controlling a negative pressure supplier connected to the vacuum chamber, the negative pressure controller, comprising:
a plurality of negative pressure sensors each configured to detect the negative pressure in the vacuum chamber; and
a negative-pressure-supplier controller configured to actuate the negative pressure supplier when one of output values of the plurality of negative pressure sensors which is nearest to an atmospheric pressure among the output values becomes nearer to an atmospheric pressure than a first threshold value, the negative-pressure-supplier controller being configured to stop the negative pressure supplier when at least two output values of the output values of the plurality of negative pressure sensors become nearer to a vacuum than a second threshold value.

2. The negative pressure controller according to claim 1 , wherein the negative-pressure-supplier controller comprises a forcible stopper configured to stop the negative pressure supplier when a first set length of time is elapsed from a time point at which an output value nearest to the vacuum among the output values of the plurality of negative pressure sensors becomes nearer to the vacuum than the second threshold value, even when the at least two output values have not become nearer to the vacuum than the second threshold value.

3. The negative pressure controller according to claim 1 , further comprising a malfunction detector configured to detect a malfunction in at least one negative pressure sensor of the plurality of negative pressure sensors when the at least two output values have not become nearer to the vacuum than the second threshold value when a second set length of time is elapsed from a time point at which an output value nearest to the vacuum among the output values of the plurality of negative pressure sensors becomes nearer to the vacuum than the second threshold value.

4. The negative pressure controller according to claim 3 , further comprising a malfunctioned-sensor identifier configured to, when the malfunction detector detects a malfunction in the at least one negative pressure sensor, identify the at least one negative pressure sensor in which the malfunction has occurred, as the malfunctioned at least one negative pressure sensor.

5. The negative pressure controller according to claim 4 , wherein the negative-pressure-supplier controller comprises a malfunction-identification controller configured to, when the malfunctioned-sensor identifier identifies the malfunctioned at least one negative pressure sensor, control the negative pressure supplier based on at least one output value of at least one of the plurality of negative pressure sensors except the identified malfunctioned at least one negative pressure sensor.

6. The negative pressure controller according to claim 3 ,
wherein the vacuum booster is operable by an operation of a brake operating member,
wherein the negative pressure in the vacuum chamber changes with the operation of the brake operating member,
wherein the malfunction detector is configured to perform measurement of an elapsed time from a time point at which an output value nearest to the vacuum among the at least two output values becomes nearer to the vacuum than the second threshold value, and
wherein the malfunction detector comprises a measurement discontinuer configured to discontinue the measurement of the elapsed time when the operation of the brake operating member is performed before the elapsed time reaches the second set length of time.

Assignees

• Toyota Motor Co Ltd

Inventors

• Sekiya Yoshihide
• Murayama Yasushi
• Ozaki Shoji

Classifications

• B60T13/52

  indirect, i.e. vacuum booster units · CPC title

• B60T13/72 Primary

  in vacuum systems {or vacuum booster units} · CPC title

• B60T17/22 Primary

  Devices for monitoring or checking brake systems; Signal devices · CPC title

• B60T13/46

  Vacuum systems · CPC title