Dosing device overcoming change in viscidity of detergent and method for controlling same

1. A delivery device for delivering a detergent independently of a change in a viscidity of a detergent, which delivery device comprising:

a detergent storage;

a pump configured to draw the detergent from the detergent storage and inject the detergent into a dissolving container;

a motor configured to drive the pump;

a delivery container communicated with the detergent storage via a first one-way valve;

the dissolving container communicated with the delivery container via a second one-way valve, the first and second one-way valves being mounted at a top of the delivery container and having opposite liquid conducting directions;

a piston disposed in the delivery container;

a crank-connecting rod mechanism connected with the motor and constituted by the delivery container, the piston, a piston rod and a crankshaft, the crankshaft including a main journal directly coupled to a secondary journal offset from the main journal, the piston rod being coupled to the secondary journal, the main journal and the secondary journal forming a recess such that when the piston is located nearest the main journal as the crankshaft rotates, the piston rod is located in the recess;

a contact switch connected with a controller of a washing machine;

a cam disposed on the main journal of the crankshaft, a point of an outer contour of the cam, which is farthest from a center of a base circle of the cam, being configured to contact the contact switch, and, in response to said contact, trigger the contact switch to turn on and off once when the crankshaft makes one revolution.

2. A method of controlling a delivery device for delivering a detergent independently of a change in a viscidity of a detergent, comprising steps of:

step 1, calculating by a controller a volume V of a detergent to be added;

step 2, calculating by the controller a number n of cycles of a doser according to the volume V of the detergent to be added and a volume vo added by a delivery container in one cycle, where n=V/vo;

step 3, counting by the controller a revolution of a motor based upon a point contacting a contact switch, and in response to the contacting, triggering the contact switch to turn on and off, the point being an outer contour of a cam disposed on a main journal of a crankshaft of the doser, the crankshaft including a secondary journal directly coupled and offset to the main journal having a piston rod coupled thereto for controlling a piston of the doser, the main journal and the secondary journal forming a recess such that when the piston is located nearest the main journal as the crankshaft rotates, the piston rod is located in the recess, and instructing by the controller the motor to stop rotation when the revolution of the motor reaches n; and

step 4, delivering the detergent into a dissolving container, and flushing the detergent into a washing tub by water to participate in washing.

3. The delivery device of claim 1 , the main journal being supported by a bearing.

4. The delivery device of claim 3 , the main journal being supported by a second bearing, the secondary journal located between the bearing and second bearing.