JPS6050282A - Constant flow pump - Google Patents

Abstract

PURPOSE:To reduce the pressure variation by coupling the suction port of measuring pump and a variable resistance to the delivery port of pressure applying pump. CONSTITUTION:The suction port I1 of suction valve Vi in a pressure applying plunger P1 is coupled with the input end I through a three-way branch joint J1 while further coupled with the end of variable resistor VR. The delivery port O1 of delivery valve VO1 is coupled with the suction port I2 of suction valve Vi2 for measuring plunger P2 through three-way branch joint J2 while further coupled with the end of variable resistor VR. When suction is performed by said plunger P2, the delivery pressure from said plunger P1 is applied onto the suction port I2 of suction valve Vi2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant flow pumping device for transferring liquid with small fluctuations.

A constant flow pump device is generally used to transfer liquid at a constant flow rate.

FIG. 1 is a structural explanatory diagram showing an example of a conventional pump arrangement of this type, in which two plungers Pa are installed.

Pb suction valve via, Vib suction port 1a, Ib connected to input end 1 via three-way branch joint J [J and C, 11 outputs (V oa, V ob) nl Kawade] Oa,
Otl is connected to the output end O via a three-way branch dicointe JO, and the plungers r--Pa and Ph are driven alternately to send out the liquid sucked in from the input end 1 to the output end 0, J: It is composed of In addition, these plunge tl
pfl, pli are, for example, λ, f*, 2, 5~3
,0-1,S]-口-ku1-2.CQ to 5111111
has been established.

However, 1, this, 1: U1 (Related to Iζ, which transfers a small amount of liquid by S), the effective volume and The disadvantage is that the dead volume ratio inside the cylinder head increases, and the adiabatic compression coefficient of the liquid greatly affects the amount of liquid fed, resulting in extremely poor constant flow performance with respect to changes in pressure. There is. In addition, the drop in constant flow quality due to pressure changes in d3 when sending a small amount of liquid is Plunge 1! - Seal member and plunger used for 1! -The pressure of the Plus Deck material used inside is a major cause of shrinkage, and even if the dead volume is reduced, the outflow will not be improved.Furthermore, the two J-lunges However, because the compression of the liquid is not sufficiently taken into consideration, a relatively large pressure change fJI (for example, about 20%
) will occur. Furthermore, due to the miniaturization of the effective volume of the cylinder, even if a small amount of air enters the cylinder head from the suction port, the operating capacity will be significantly reduced, which is undesirable. Since the reduction rate of the dead volume inside the cylinder head is small compared to the reduction rate of the effective volume of the cylinder head, it takes a long time to switch between different types of liquids when sending a small amount of liquid. Furthermore, by shortening the suction and discharge cycles of the pump, the baseline noise can be greatly improved, but if the suction speed is increased, 4-17 bitation occurs inside the cylinder head, making stable liquid delivery impossible.

The present invention has been made in view of these points, and its purpose is to realize a constant flow pump design with excellent characteristics especially for slightly open "X15" liquid.

The configuration of the invention that achieves this objective comprises an H pump, a metering pump, a variable resistor, and! j pressure bomb l river f
It is characterized in that the XI ld pump's suction [1] and a variable resistor are connected to ll l-'I.

1) Detailed explanation of the present invention will be given below with reference to the drawings.

FIG. 2 11 is an explanatory diagram of the configuration of an embodiment for A light. 1 In Fig. 2, the suction valve \/i+ of the pressurized plunge tl P+ has a three-way branch joint
+ 1'i [No 1 person horn end 1 is connected], the end of the variable resistor VR is connected, and the leaf of the discharge valve\101 Ill I-,,10I (LE, 11 minutes When the suction port I2 of the suction valve vi2 of the metering plunger [2] is connected through the passage 1 int-, J2, the variable resistor V
The ends of R are connected at 1+. 11 hl plunge P
Pl's [1 outgoing valve VO? 102 is the edge of the protruding horn (°
) is connected to C.

41. /,: The operation of the constant flow pump device will be explained using the operation explanatory diagram of FIG. 3. 1 In FIG. This completes the process of jars 1) and 2. As is clear from Figure 3, 'i I'
i-plunge tP+ repeats exhalation → inhalation → supplies 1 no.
The split M plunger P2 repeats suction → 3-discharge → suction. Here, pressurized plunge l/Ps
The discharge period is metering plunge t! - Pressurized plunge longer than the inhalation period of P2? The suction period of P+ is set earlier than the discharge period of metering plunger P2. That is, the discharge stroke of pressure plunger P1 starts before the discharge stroke of meter-plunger P2 ends, and the metering plunger The suction stroke of pressurized plunger P1 ends after the next discharge stroke of sea P2 starts, and the suction stroke of pressurized plunger P1 begins with metering plunger P2.
The metering plunge 1 starts after the ri1 exit stroke begins.
! - It ends before the discharge stroke of P2 ends. As a result, when the metering plunger P2 performs suction, the pressure due to the discharge of the pressurized plunger 1l-Pl is applied to the suction [1*2] of the suction valve Vi2.

Note that the variable resistance VR is the suction valve v of the metering plunger P2.
If the pressure at the suction port 12 of i2 is pin, and the pressure at the discharge port o2 of the discharge valve V02 is p out, then Pollt>Pi
The value is adjusted so that the relationship n holds true.

In this way, according to this embodiment, the liquid to be transferred 4-fA l: from the L person's horn end l! j pressure is applied to the metering plunger t□ Pl and the variable resistor VR via the plunger P1, and the predetermined ti is applied from the KIIT plunger 11-1) 2.
When each signal is sent to the output terminal O, the residual (variable resistor V
It will be returned to pressurized plunge zy-P1 via R.

As a result, with one metering plunge +y-P2, it is possible to reduce the force and thrust, and it is possible to improve the constant flow collapsibility against different fluids and pressure changes. In addition, problems caused by air inhalation, which are conventional, can be significantly reduced. In addition, even if the suction time is set to λ(j), cavitation does not occur inside the cylinder head, and the liquid can be stably fed, thereby lowering the baseline noise.

Furthermore, when the square tube of the pump LX IY/ changes, the resistance value of the resistor VR is adjusted to keep the pressure difference at the suction of the metering plunger constant. 1, it is possible to further improve the constant flow performance of the pump device.

FIG. 4 is a configuration explanatory diagram showing another embodiment of the present invention, in which the end of the variable resistor VR in FIG. 3 is opened. Thereby, the liquid is not returned from the variable resistor VR to the pressurized plunger P+, and the time required for switching between different liquids can be shortened.

FIG. 5 is also a configuration explanatory diagram showing another embodiment of the present invention, in which two metering plungers P2 and Ps are used to connect the end of the variable resistor VR to the suction valve Vi of the pressurized plunger 1r-Pl.
It should be returned to the inlet port of l. This provides liquid delivery characteristics with even smaller pressure fluctuations.

FIG. 6 shows an open end of the variable resistor VR in FIG. 5, and the same effect as in FIG. 4 can be obtained.

Although plungers were used as the supply Ui pump and the metering pump in the above-described embodiments, it goes without saying that similar effects can be obtained by using a diaphragm pump.

As explained below, according to the present invention, a constant flow open pump Hi& with excellent micro-level liquid transfer characteristics can be realized, and is suitable for 8 types of analyzers, 15 chemical injection devices, etc., and its effects are as follows. I like people.

[Brief explanation of the drawing]

FIG.
FIG. 2 is a structural explanatory diagram showing one embodiment of the present invention, FIG. 3 is an explanatory diagram of the operation of FIG. 2, and FIGS. 4 to 6 are structural explanatory diagrams showing other embodiments of the present invention. It is. Pl...tj pressure plunger Pz, r'3...monthly stone plunger J I~LJ
4...Three-way branch joint VR...Variable 11 (anti-■...Input width; 0...Output end 'i!1 revision Applicant Applicant Hondenshi Co., Ltd. Agent Patent attorney "Tsukishima Fuji th 〇 − 〉 〇〇 − 〉 〉 Evening 〉 = 0 ・− 〉 〉

Claims (2)

[Claims] (1) A constant flow pump device comprising a pressurized pump, a hanging bong 1, and a variable resistor, and characterized in that the pressurized pump supplies 1 are connected to the suction port of a metering pump and the variable resistor. (2) The constant flow pump device according to claim 1, characterized in that the end of the variable resistor is open.