US 11,639,680 B2Granted

Urea water supply system

AssigneeDenso Corporation

InventorsTomoaki Kamei, Tomohiro Ueno, Eiji Takemoto, Sumitaka Ikeda

Life of this patent

Estimating the term…

Loading patent…

Abstract

A urea water supply system includes: a first supply valve for supplying urea water; a second supply valve for supplying urea water; a supply passage for connecting a urea water tank and the first and the second supply valves; and an electronic control unit (ECU). The supply passage branches to have a first supply passage extending from a branch point to the first supply valve and a second supply passage extending from the branch point to the second supply valve, and a volume of the first supply passage is greater than a volume of the second supply passage. The ECU opens the first supply valve while keeping the second supply valve closed, for starting filling of the supply passage with urea water, and thereafter determines completion of filling of urea water into the first supply passage.

Claims21

Dependent claims

A urea water supply system provided in an exhaust passage of an internal combustion engine for supplying urea water, which is used in an exhaust gas purification device having first and second catalysts among which the first catalyst is a selective reduction type catalyst provided in the exhaust passage of the internal combustion engine and purifying nitrogen oxide in an exhaust gas using ammonia,

the urea water supply system comprising:
a first supply valve for supplying urea water to an upstream of the first catalyst in the exhaust passage;
a second supply valve for supplying urea water to an upstream of the second catalyst in the exhaust passage;
a urea water tank for storing urea water;
a supply passage provided to connect the urea water tank with each of the first supply valve and the second supply valve and through which the urea water passes;
a pump for pumping the urea water from the urea water tank to the supply passage;
a pressure detector that detects a pressure value of the urea water;
and
a controller for performing drive control of the pump and open/close control of the first supply valve and the second supply valve, wherein
the supply passage is branched en route to the two valves, and includes:
(i) a common passage extending from the urea water tank to a branch point,
(ii) a first supply passage extending from the branch point to the first supply valve and connected to the first supply valve for supplying urea water to the first supply valve, and
(iii) a second supply passage extending from the branch point to the second supply valve and connected to the second supply valve for supplying urea water to the second supply valve,
a volume of the first supply passage is greater than a volume of the second supply passage, and
the controller is configured to:
(i) open the first supply valve and drives the pump to pump the urea water while keeping the second supply valve closed, thereby starting filling of the first supply passage and the common passage with the urea water,
(ii) determine completion of filling of the first supply passage with urea water based on a pressure value detected by the pressure detector, and
(iii) close the first supply valve upon detecting the completion of urea water filling in the first supply passage.

15 more elements

A controller for controlling a urea water supply system, wherein the urea water supply system includes:

a urea water tank, a pump, a pressure sensor, a branch point, a common passage located between the pump and the branch point, a first supply valve, a first supply passage located between the branch point and the first supply valve and connected to the first supply valve for supplying urea water to the first supply valve, a second supply valve, and a second supply passage located between the branch point and the second supply valve and connected to the second supply valve for supplying urea water to the second supply valve, and wherein the controller comprises:
a processor;
and
a non-transitory computer-readable storage medium, and
wherein the controller is configured to:
drive the pump;
open the first supply valve to cause the first supply valve to inject urea water supplied from the first supply passage while keeping the second supply valve closed thereby starting filling of the first supply passage and the common passage with the urea water;
determine that a pressure is greater than or equal to a first threshold value;
close the first supply valve;
open the second supply valve to cause the second supply valve to inject urea water supplied from the second supply passage;
determine that the pressure is greater than or equal to a second threshold value;
and
close the second supply valve.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/587,431Filed 28 Jan 2022
Priority: JP JP2021-0182698 Feb 2021
Published: US 2022/0251988 A111 Aug 2022
Granted: 2 May 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification25 codes

F01N 3/208
Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing…:…
B01D 53/9418
Processes characterised by a specific catalyst: for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a…
B01D 53/9431
Nitrogen oxides: processes characterised by a specific device
B01D 53/9495
By catalytic processes: controlling the catalytic process