JPH08247042A - Liquid feed pump - Google Patents

Abstract

PURPOSE: To effectively remove the shavings of plunger seals generated at the time of operation by fitting a filter on a passage from a pump chamber to a valve on the suction side or on a passage from the pump chamber to a valve on the discharge side. CONSTITUTION: A plunger reciprocating pump is provided with a pump head 1, a plunger 5 reciprocated in a pump chamber 10 through plunger seals 8, 9 fixed by a cleaning mechanism/seal presser 4, a valve 2 on the suction side, and a valve 3 on the discharge side. The plunger 5 is reciprocated by the rotating motion of a constant-speed disk cam via a plunger rod 6, pressurizes the fluid sucked via the valve 2 on the suction side, then discharges it via the valve 3 on the discharge side. Filters 11, 16 are provided at portions of the valves 2, 3 on the pump chamber 10 side to capture foreign matters. A sintered filter of a metal or a filter made of a solvent-resistant resin is preferably used for the filters 11, 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger-reciprocating liquid-sending pump for sending a liquid and a valve suitably used for such a liquid-sending pump. More specifically, the present invention relates to a reciprocating motion of a plunger. Plunger series
TECHNICAL FIELD The present invention relates to a valve suitable for use in a liquid feed pump, which is equipped with a liquid feed pump having a filter so as not to mix shavings and the like in the flow path.

[0002]

2. Description of the Related Art Conventionally, in the field of liquid chromatography and the like, a syringe type liquid feed pump has been used for the purpose of pressure-feeding a liquid used for analysis such as a sample to be analyzed or an eluent to a column (for example, (See Japanese Patent Publication No. 63-53508).

In liquid chromatography and the like, it is necessary to remove dust mixed in the liquid used for the analysis in order to prevent clogging of the column, liquid feed pump and the like.
A method for removing dust mixed in a liquid (sample solution, etc.) used for analysis has been proposed, for example, by equipping a filter in the suction port of the liquid to be fed and the flow path leading to the liquid feed pump. There is.

[0004]

In the liquid feed pump in which the plunger is constantly in contact with and rubbed against the plunger seal, such as the plunger reciprocating liquid feed pump, the liquid used for the above-mentioned analysis is In addition to the originating waste, the waste generated from the liquid delivery pump itself, such as the scraps of the plunger seal, poses a problem. In this way, the dust generated from the liquid feeding pump flows out together with the liquid pumped from the pump chamber, and when it reaches the suction side valve and / or the discharge side valve and accumulates, it may cause malfunction of the valve. There is a nature.

[0005]

As described above, the present inventor has found that, in the plunger-reciprocating liquid feed pump, the malfunction of the valve causing the liquid feeding trouble is rather the dust mixed in the liquid used for the analysis. It was found that this was due to dust generated from the pump itself, such as scraps of the plunger seal that occur when the plunger reciprocates, and as a result of intensive studies to solve this, the present invention was completed. It was

That is, according to the present invention, in a plunger-reciprocating liquid feed pump for feeding a liquid, the flow passage from the pump chamber to the valve on the suction side or the flow passage from the pump chamber to the valve on the discharge side is provided. A liquid feed pump having a filter attached to one of them, particularly preferably a plunger reciprocating liquid feed pump for feeding a liquid, from a flow path from the pump chamber to a valve on the suction side and from the pump chamber. It is a liquid feed pump in which filters are attached to both of the flow paths up to the valve on the discharge side.

Further, the present invention is a valve on the suction side used in such a plunger-reciprocating liquid feed pump, which has a filter on the side where the liquid flows out or a valve which has a filter on the side where the liquid flows in. Is. Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a check valve (2, 3) as an example.
1 shows a liquid delivery pump of the present invention including the above. The plunger-reciprocating pump includes a pump head 1, a plunger seal 8 fixed by a seal holder 4 serving also as a cleaning mechanism,
It is composed of a plunger 5 penetrating 9 and reciprocating in the pump chamber 10, a suction side valve 2 and a discharge side valve 3. The end of the plunger rod 6 connected to the plunger 5 is in contact with an unillustrated constant velocity disc cam or the like, and the plunger rod 6 reciprocates as shown by the rotational movement of the constant velocity disc cam or the like. As a result, the plunger-5 is in the pump chamber 1
Reciprocates within 0. It should be noted that the suction side valve 2 and the discharge side valve 3 are not particularly limited and may be ordinary valves, but a check valve having a relatively simple configuration can be exemplified as a preferable valve.

The seal holder 4, which also serves as a cleaning mechanism, has a cleaning liquid supply hole 14 for cleaning the plunger 5 therein, and flows from the cleaning liquid reservoir 15 into the cleaning liquid supply hole 14 through the cleaning pipe 7 and the plunger. The plunger 5 is washed with a washing liquid which fills the space closed by the seals 8, 9.

Usually, the plunger seals 8 and 9 are preferably made of a member having excellent wear resistance, such as silicon, but are scraped by the reciprocating motion of the plunger 5 for a long time to remove dust. Will occur. The dust thus generated can be removed to some extent by the above-mentioned cleaning mechanism, and it is preferable to provide such a cleaning mechanism also in the present invention, but a part of it enters the pump chamber 10,
The valves 2 and 3 are reached by the reciprocating movement of the plunger 5.

Therefore, in the present invention, a filter is provided on the discharge side of the valve 2 on the suction side, that is, the pump chamber 10 side, and / or on the suction side of the valve 3 on the discharge side, that is, the pump chamber 10 side. . Normally, the dust moves toward the valve 3 on the discharge side due to the pressure generated by the reciprocating motion of the plunger 5,
If one of the valves is provided with a filter, it should be provided on the discharge side valve 3, but it may be provided only on the suction side valve 2 for the purpose of preventing malfunction of the suction side valve.
Note that it is particularly preferable to provide both valves for the purpose of preventing malfunction of the liquid delivery pump as a whole.

The specific filter mounting location is not particularly limited as long as it is a flow path from the pump chamber to the valve on the suction side or the discharge side, but in order to avoid complicated filter replacement and the like. It is preferable to attach each valve immediately (or just before) as shown in the figure. The filter may be sandwiched between the pump head 1 and the suction side or discharge side valve (2 or 3) so that the filter can be replaced when the pump is used for a certain period of time. It is particularly preferable that the filter is separable and integral with the valve by screwing or fitting.

The filter used in the present invention is 1 to 50.
As long as it has pores of about .mu.m, preferably about 5 to 30 .mu.m, it is possible to remove the scraps of the plunger seal. The material is also capable of withstanding the pressure generated by the plunger pump, and
There is no limitation as long as it does not deteriorate when it comes into contact with the liquid to be sent, but for example, a metal sintered filter-
A resin filter having solvent resistance is preferable.

According to the liquid feed pump of the present invention having the above structure, the liquid to be fed from the liquid reservoir 12 to be fed to the pump chamber 10 by the retreat of the plunger 5 is introduced into the introduction pipe 13 and the suction side. The liquid to be sent from the pump chamber 10 due to the forward movement of the plunger 5 flows out via the valve 3 on the discharge side. At this time, dust such as shavings of the plunger seal generated from the pump main body is removed by a filter attached to the valve proximity chamber on the suction side or the discharge side.

FIG. 2 is a view showing the details of the valves 2 and 3 in FIG. 1, and shows a check valve which is a preferred example of the valve in the present invention, but as described above, in the present invention. The valve may be, for example, a solenoid valve or the like, which can restrict the movement of liquid in one direction.

The valve 2 on the suction side allows the liquid to move only in the direction of the arrow (the direction from c to d) in the figure, and the filter 11 can be fitted on the pump chamber side (d).
On the other hand, the valve 3 on the discharge side allows the liquid to move only in the direction of the arrow (the direction from e to f) in the figure, and is on the pump chamber side (e).
It is possible to fit a filter-16 into the. The filter used may be the one described above. The filter may be attached to the valve not only by fitting but also by screwing or the like.

[0017]

EFFECTS OF THE INVENTION The plunger-reciprocating liquid feed pump has been widely used in the field of liquid chromatography since it is easy to drive and control the pressure in the pump chamber and has a simple structure. ing. The present invention focuses on the point that dust generated from the liquid feed pump itself, such as shavings of the plunger seal caused by the reciprocating motion of the plunger in such a liquid feed pump, causes valve malfunction. The present invention provides a liquid delivery pump that can be used.

Therefore, according to the liquid feed pump of the present invention, it is possible to realize a favorable valve operation as compared with the conventional liquid feed pump. In particular, in addition to the constitution of the present invention, in order to remove dust mixed in the liquid used for analysis, a filter is provided in the flow path leading to the suction port of the liquid to be fed and the liquid feed pump. With this, it is possible to completely remove dust that causes malfunction of the valve.

In the liquid delivery pump of the present invention,
By replacing or cleaning the filter when the pump is driven for a certain period of time, stable valve operation is always guaranteed.

The valve of the present invention is a member constituting a liquid feed pump or the like, but the structure of the liquid feed pump of the present invention can be realized by attaching such a valve to a conventional liquid feed pump. is there. Moreover, the filter can be easily exchanged or cleaned by connecting the filter to the valve such that the filter can be separably fitted or screwed.

In the conventional liquid feed pump, if the valve malfunctions, for example, in liquid chromatography, the analysis operation is interrupted, and it is sometimes difficult to continue the analysis, and naturally the valve is disassembled. It is necessary to replace it with a new one. On the other hand, in the liquid delivery pump of the present invention, even if the analysis operation is interrupted, the operation can be promptly restarted only by cleaning or replacing the filter portion.

[Brief description of drawings]

FIG. 1 is a sectional view of a plunger-reciprocating liquid feed pump of the present invention.

FIG. 2 shows a valve (check valve) on the suction side or the discharge side of the present invention.

[Brief explanation of reference numerals] 1 pump head 2 suction side valve (check valve) 3 discharge side valve (check valve) 4 cleaning mechanism combined seal holder 5 plunger 6 plunger rod 7 cleaning pipe 8, 9 plunger -Seal 10 Pump chamber 11, 16 Filter-12 Liquid reservoir 13 Introducing pipe 14 Cleaning liquid feed hole 15 Cleaning liquid reservoir

Claims (12)

[Claims] 1. In a plunger-reciprocating liquid feed pump for feeding a liquid, one of a flow passage from a pump chamber to a valve on a suction side or a flow passage from a pump chamber to a valve on a discharge side. Liquid transfer pump with filter attached to. 2. A plunger reciprocating liquid feed pump for feeding a liquid, wherein a filter is attached to a passage extending from a pump chamber to a valve on a suction side. Liquid pump. 3. A plunger reciprocating liquid feed pump for feeding a liquid, wherein a filter is attached to a passage extending from the pump chamber to a valve on the discharge side. Liquid pump. 4. A plunger-reciprocating liquid feed pump for feeding a liquid, wherein a filter is provided both in the flow passage from the pump chamber to the valve on the suction side and on the flow passage from the pump chamber to the valve on the discharge side. -A liquid feed pump equipped with. 5. The liquid feed pump according to claim 1, wherein the filter has a pore size of 1 to 50 μm. 6. The liquid feed pump according to claim 1, wherein the filter is a sintered metal filter or a resin filter having solvent resistance. 7. The liquid delivery pump according to claim 1, wherein the suction side valve and / or the discharge side valve is a check valve. 8. A valve which is a suction side valve used in a reciprocating liquid feed pump for feeding a liquid, and which has a filter on the side where the liquid flows out. 9. A valve for supplying a liquid to a plunger and a valve on the discharge side used in a reciprocating liquid transfer pump, the valve having a filter on the side into which the liquid flows. 10. The valve according to claim 8 or 9, wherein the pore size of the filter is 1 to 50 μm. 11. The valve according to claim 8, wherein the filter is a sintered metal filter or a resin filter having solvent resistance. 12. The valve according to claim 8, which is a check valve.