Control valve that can achieve both large and small color paste discharge

摘要

A pump capable of dispensing both a large volume and a small volume of colorant comprises a large reciprocating positive displacement pump having a large reciprocating part, a large pump body and a large pump inlet-outlet opening, characterized in that: a small reciprocating part fixed to the large reciprocating part is disposed in the large pump body; a small pump body is disposed on a base of the large pump body, and provided with a small pump inlet-outlet opening; and the small reciprocating part, the small pump body and the small pump inlet-outlet opening constitute a small reciprocating positive displacement pump. The reciprocating positive displacement pump provided in the present invention may achieve dispensing of both a large volume and a small volume of colorant by means of a large-section pump, and thus guarantees the accuracy of the dispensed volume of colorant, and in particular, the accuracy of dispensing of a small volume of colorant; and the reciprocating positive displacement pump, when compared with the prior art, has the advantages of high accuracy and simple structure, and when compared with the structure in patent No. US2009236367A1, has the advantages of good leakproofness, high utilization of a reciprocating pump cylinder body in the length direction, and improved stroke accuracy of the reciprocating pump due to less elastic deformation of a pump support.