# US 2021/0172437 A1 · Liquid sending device

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- Number: US 2021/0172437 A1
- Document ID: US20210172437A1
- Status: Published application
- Kind: A1
- Application number: 16/768,660
- Filed: 2018-06-20
- Published: 2021-06-10
- Earliest claimed: 2017-12-25
- Assignees: Shimadzu Corporation
- Applicants: Shimadzu Corporation
- Inventors: Shinya IMAMURA; Keisuke OGAWA
- Web page: https://patentgrep.com/patent/US20210172437A1

## CPC

- F04B 53/1087: {Valve seats}
- G01N 30/16: Injection (G01N30/24 takes precedence)
- F04B 7/0076: {the members being actuated by electro-magnetic means}
- F04B 49/03: by means of valves
- F04B 49/06: Control using electricity (regulating by means of floats actuating electric switches F04B49/04)
- F04B 49/065: {and making use of computers}
- F04B 49/08: Regulating by delivery pressure
- F04B 53/1002: {Ball valves}
- F04B 53/1007: {having means for guiding the closure member}
- F04B 53/101: {having means for limiting the opening height}
- F16K 31/0655: {Lift valves}
- F04B 49/22: by means of valves (F04B49/03 takes precedence)
- F16K 31/08: using a permanent magnet
- G01N 30/32: of pressure or speed (G01N30/36 takes precedence)
- G01N 2030/326: {pumps}
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}

## Abstract

A liquid sending device includes a plunger pump, which performs an intake operation of liquid to and a discharge operation of liquid from a pump chamber and in which pressure in the pump chamber in a case where the intake operation is performed is lower compared to a case where the discharge operation is performed, a check valve that is provided at an inlet port, has a spherical valve element and a valve seat, and passively operates according to the pressure in the pump chamber in such a direction that the valve element is seated on or detached, a pressure sensor that detects the pressure, and an attachment detector that compares the pressure with a preset threshold value and detect attachment of the valve element to the valve seat in a case where the pressure in the pump chamber is equal to or lower than the threshold value.

## Claims

### Claim 1

A liquid sending device comprising:
a plunger pump, which performs an intake operation of liquid to and a discharge operation of liquid from a pump chamber and in which pressure in the pump chamber in a case where the intake operation is performed is lower compared to a case where the discharge operation is performed,
a check valve that is provided at an inlet port of the plunger pump, has a spherical valve element and a valve seat on which the valve element is to be seated, and passively operates according to the pressure in the pump chamber in such a direction that the valve element is seated on or detached from the valve seat,
a pressure sensor that detects the pressure in the pump chamber; and
an attachment detector that is configured to compare the pressure in the pump chamber detected by the pressure sensor with a preset threshold value and detect attachment of the valve element to the valve seat in a case where the pressure in the pump chamber is equal to or lower than the threshold value.

### Claim 2 (depends on 1)

The liquid sending device according to claim 1, wherein
the check valve has a valve element driver for actively driving the valve element seated on the valve seat in such a direction that the valve element is detached from the valve seat,
the liquid sending device includes a valve element drive controller for controlling an operation of the valve element driver, and
the valve element drive controller is configured to actively drive the valve element by the valve element driver in such a direction that the valve element is detached from the valve seat, only in a case where the attachment detector detects attachment of the valve element to the valve seat.

### Claim 3 (depends on 2)

The liquid sending device according to claim 2, wherein
the valve element driver includes a pin provided to be movable inside of the valve seat and an operating element that causes the pin to operate and press the valve element in such a direction that the valve element is detached from the valve seat, and
at least a portion, which slides inside of the valve seat, of the pin is made of a same material as the valve seat.

### Claim 4 (depends on 2)

The liquid sending device according to claim 2, wherein
the valve element driver includes a pin provided to be movable inside of the valve seat and an operating element that causes the pin to operate and press the valve element in such a direction that the valve element is detached from the valve seat, and
diamond-like carbon coating is applied to at least one of an outer peripheral surface of the pin and an inner side surface of the valve seat.