Shot pump and variable-speed-type two-liquid metering and mixing apparatus

1. A shot pump comprising:

a cylinder standing upright in a vertical direction;

an inlet having a check valve which allows a paste-like transferred substance to only flow into the cylinder therethrough, the inlet being provided at a lower end portion in a side face of the cylinder so as to be contiguous to a lower end face of the cylinder without a step difference between the lower end surface of the inlet and the lower end surface of the cylinder;

an outlet having a check valve which allows the transferred substance to only flow out of the cylinder therethrough, the outlet being provided at an upper end portion in the side face of the cylinder so as to be contiguous to an upper end face of the cylinder without a step difference between the upper end surface of the outlet and the upper end surface of the cylinder; and

a piston configured to vertically reciprocate in the cylinder so as to cause the transferred substance to be sucked from the inlet and then to be discharged from the outlet, wherein

the ratio of a clearance between a side face of the piston and an inner side face of the cylinder to an outside diameter of the piston is 1/50 to 1/2, and

the transferred substance is sucked from the inlet, is then caused to pass through the clearance between the side face of the piston and the inner side face of the cylinder, and is discharged from the outlet.

2. The shot pump according to claim 1 , wherein the inlet and the outlet are arranged respectively in portions opposite to each other of the side face in a vertical cross section of the cylinder.

3. A variable-speed-type two-liquid metering and mixing apparatus comprising:

a shot pump for a main agent, in which the main agent is filled from a material supply source while the pressure at the completion of the filling is settable at a predetermined constant value;

a shot pump for a curing agent, in which the curing agent is filled from a material supply source while the pressure at the completion of the filling is settable at a predetermined constant value;

drive motors which are provided respectively to the shot pump for the main agent and the shot pump for the curing agent;

a mixer,

wherein the main agent and the curing agent are pushed out from the corresponding shot pumps driven respectively by the drive motors, and are mixed by the mixer while the mixing ratio of the main agent and the curing agent can be set at an arbitrarily predetermined ratio by controlling the rotational speeds of the respective drive motors, and the resultant mixed agent is then discharged,

each shot pump includes: a cylinder standing upright in a vertical direction; an inlet having a check valve which allows a paste-like transferred substance to only flow into the cylinder therethrough, the inlet being provided at a lower end portion in a side face of the cylinder so as to be contiguous to a lower end face of the cylinder without a step difference between the lower end surface of the inlet and the lower end surface of the cylinder; an outlet having a check valve which allows the transferred substance to only flow out of the cylinder therethrough,the outlet being provided at an upper end portion in the side face of the cylinder so as to be contiguous to an upper end face of the cylinder; without a step difference between the upper end surface of the outlet and the upper end surface of the cylinder; and

a piston,

wherein the ratio of a clearance between a side face of the piston and an inner side face of the cylinder to an outside diameter of the piston is 1/50 to 1/2, and

the transferred substance is sucked from the inlet when the piston moves from a lower end side to an upper end side of the cylinder, and the transferred substance is then caused to pass through the clearance between the side face of the piston and the inner side face of the cylinder so as to be discharged from the outlet when the piston moves from the upper end side to the lower end side of the cylinder.