JPS6244136Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plunger pump in which a plunger moves back and forth within a pumping cylinder to transport liquid.More specifically, the present invention relates to a plunger pump in which a plunger moves back and forth within a pumping cylinder to transport liquid. This invention relates to a plunger pump that eliminates fluctuations in the amount of liquid fed by preventing this.

Conventionally, a plunger reciprocates inside a cylinder,
Plunger pumps that transport liquid within a cylinder are widely used as metering pumps. Plunger pumps can easily change the flow rate by changing the stroke width of the plunger, and while the stroke width is fixed at a predetermined width, the volume of liquid pushed out with one stroke is constant. It is easy to maintain a constant flow rate and is suitable as a metering pump. However, if gas is dissolved in the transport liquid, bubbles may be generated in the transport liquid due to changes in temperature, pressure, etc. This may cause a reduction in the check valve effect, or cause an error in the amount of liquid to be fed since gas is compressible. In order to prevent such fluctuations in flow rate and maintain the metering accuracy of the pump, conventional plunger pumps have a passage vertically connecting the lower check valve and the upper check valve, and communicate with this passage. The pumping cylinder is designed horizontally for reasons of space and function. Therefore, when air bubbles enter the pumping cylinder, the upper wall of the pumping cylinder prevents the air bubbles from rising and the air bubbles stay near the upper wall of the pumping cylinder, which reduces the metering accuracy of the pump. There was a problem.

The present invention has been made to improve the above-mentioned situation, and in a plunger pump in which the transport liquid passage connecting the lower check valve and the upper check valve is vertical, the pumping cylinder in which the plunger reciprocates is connected to the transport liquid. 90 degrees beyond 0 degrees with respect to the passage of
formed with an upward slope at an angle of less than a degree;
And to provide a plunger pump which communicates directly with a transport liquid passage, prevents air bubbles from stagnation by causing bubbles in the pumping cylinder to rise within the pumping cylinder and flow into the transport liquid passage, and improves quantitative accuracy. The purpose is to

Hereinafter, one embodiment of the present invention will be described with reference to the drawings while comparing it with a conventional example.

FIG. 1 shows a conventional example, and FIG. 2 shows an embodiment of the present invention.

In the figure, reference numeral 1 denotes a pump head, in which a passage 2 for transporting liquid is formed in a vertical direction. A lower check valve 5 consisting of a valve seat 3 and a ball 4 is formed on the lower side of this passage 2, and an upper check valve 8 consisting of a valve seat 6 and a ball 7 is formed on the upper side. has been done. The pump head 1 also includes a transport liquid passage 2 sandwiched between both check valves 5 and 8.
A pumping cylinder 9 is bored in communication with the pump cylinder 9, and a plunger 11 is inserted into the pump cylinder 9 in a liquid-tight manner and movable back and forth by a gasket 10. Note that the plunger 11 is connected to an electric motor via a crank (not shown). In this case, due to the reciprocating motion of the plunger 11, a certain amount of liquid flows in from the lower check valve 5 and is discharged from the upper check valve 8. However, if air bubbles are present in the liquid, as shown in FIG. In conventional pumps, air bubbles may enter the pumping cylinder 9, and in this case, the upper wall 12 of the pumping cylinder 9 prevents the air bubbles from rising, and the air bubbles remain near this upper wall. . In contrast, in the pump according to the embodiment of the present invention shown in FIG.
Even if the pumping cylinder 9 enters the liquid passage 2, the pumping cylinder 9 is formed with an upward slope of more than 0 degrees and less than 90 degrees, and is directly connected to the passage 2, so that air bubbles are prevented. Since the upward movement is not blocked by the upper wall 12 of the pumping cylinder 9 and the air bubbles smoothly reach the upper check valve and are removed from the pump, no air bubbles remain inside the pump.

As explained above, the present invention provides a pair of check valves at the upper and lower parts of the transport liquid passage formed vertically in the pump head, which allows the transport liquid to flow only from the lower side to the upper side. In the plunger pump, which communicates with the passageway to form a pumping cylinder, and pumps the transport liquid by reciprocating motion of a plunger fluid-tightly inserted into the pumping cylinder, the pumping cylinder is connected to the transport liquid. is formed with an upward slope at an angle of more than 0 degrees and less than 90 degrees with respect to the passage of the pumping cylinder, and is in direct communication with the passage of the transport liquid, so that the air bubbles in the pumping cylinder rise within the pumping cylinder. By allowing the liquid to flow into the transport passage, air bubbles are prevented from stagnation in the pumping cylinder, so even if air bubbles enter the pumping cylinder, the upper wall of the pumping cylinder will prevent the air bubbles from rising due to their buoyancy. do not have. Therefore, air bubbles do not stay inside the pumping cylinder,
Since air is smoothly expelled to the outside of the pump, there is no reduction in check valve effectiveness caused by air bubbles remaining inside the pump, or pressure loss caused by air bubbles forming a cushion, thereby improving the pump's quantitative accuracy. There is no decrease in

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a pump head portion of a conventional plunger pump, and FIG. 2 is a sectional side view showing a pump head portion of a plunger pump according to an embodiment of the present invention. 1... Pump head, 2... Transport liquid passage,
5...Lower check valve, 8...Upper check valve, 9...
...pumping cylinder, 11...plunger.

Claims (1)

[Scope of utility model registration request] A pair of check valves that allow the flow of the transport liquid only from the lower side to the upper side are disposed at the upper and lower parts of the transport liquid passage formed vertically in the pump head, and communicate with the passage. In a plunger pump that forms a pumping cylinder and pumps a transport liquid by reciprocating motion of a plunger that is fluid-tightly inserted into the pumping cylinder, the pumping cylinder is set at an angle of more than 90 degrees with respect to the passage of the transport liquid. formed with an upward slope at an angle of less than 100 degrees and in direct communication with the transport liquid passageway so that air bubbles within the pumping cylinder rise within the pumping cylinder and flow into the transport liquid passageway; A plunger pump characterized by: