CN1673735A

CN1673735A - Liquid delivery pump for liquid chromatograph

Info

Publication number: CN1673735A
Application number: CNA2005100590739A
Authority: CN
Inventors: 麻生喜昭
Original assignee: Shimadzu Corp
Current assignee: Shimadzu Corp
Priority date: 2004-03-25
Filing date: 2005-03-22
Publication date: 2005-09-28
Anticipated expiration: 2025-03-22
Also published as: CN1317558C; JP4086001B2; US20050214139A1; JP2005274391A

Abstract

A cross head 10 and a plunger 2 are connected freely turnably, by connecting screwingly the plunger 2, to a spherical plunger holder 15 abutting to an end part flat face 10a of the cross head 10 reciprocated while driven by rotation motion of a cam 11. The manufacturing cost is reduced because bearing balls are used as spherical bodies, and the maintenance cost is also reduced because only the plunger 2 is required to be removed from the plunger holder 15 and to be replaced, when the plunger 2 is abraded.

Description

Liquid delivery pump for liquid chromatograph

Technical field

The present invention relates to liquid delivery pump for liquid chromatograph, relate to be supported on the structure of reciprocating plunger in the pump chamber in more detail.

Background technology

Fig. 2 is the figure that represents an example of liquid delivery pump for liquid chromatograph in the past with sectional view.In the figure, the 1st, head (pump head), the 2nd, plunger, the 3rd had not only prevented leak of liquid but also can make the seal element, the 4th of plunger 2 motions, the pump chamber, 5 and 6 that forms in the head 1 is respectively the suction inlet of the liquid that is transferred and escape hole and is equipped with

non-return valve

5a and 6a separately.The 7th, the pump housing, the 8th, bearing, the 9th, spring, the 10th, slide block (cross head), the 11st, by the cam, the 12nd of not shown motor driven rotation, the Cam Follower that rotates along the periphery of cam 11.

The front of plunger 2 (left side among Fig. 2) by seal element 3 be inserted in the pump chamber 4, its base end side (right side among Fig. 2) is connected with slide block 10 simultaneously.The power of the working direction (left-hand Fig. 2) that loads through Cam Follower 12 by cam 11 by the slide block 10 of 8 supports of bearing and to-and-fro movement in the pump housing 7 cylindraceous by the power of the direction of retreat (dextrad among Fig. 2) of spring 9 loadings from rotation.With this motion interlock, plunger 2 to-and-fro movement in pump chamber 4, and, accompany therewith, flow from the liquid of suction inlet 5, carry out liquor charging towards escape hole 6 by the effect generation of two non-return valve 5a and 5b because of this motion causes pressurizeing in the pump chamber 4 and reducing pressure repeating alternately.

The material of plunger 2 is used the good sapphire of hardness height and wearing quality and chemical proof (sapphire) etc. more, also has use the surface to be carried out the example (for example, with reference to patent document 1) of the metal of coating processing with ceramic membrane.

Fig. 3 has further described the structure of plunger 2 with the connecting portion of slide block 10.Among Fig. 3, the formation element identical with Fig. 2 paid same symbol, so omit its explanation.The 15th, the plunger frame, the one end is fixed with the base end part of plunger 2, and the other end is processed to sphere and form end sphere 15a.This plunger frame 15 can be pressed in the slide block 10 by thread ending cover 16, thereby plunger 2 and slide block 10 are coupled together.The end sphere 15a of plunger frame 15 and the end tabular surface 10a of slide block 10 connect to contact, thereby it is arbitrarily angled to make that plunger 2 can the limit be followed the rotation of slide block 10 to-and-fro movement limits.By said structure, prevented from that plunger 2 from moving to produce in the to-and-fro movement of limit relative to seal element shown in Figure 23 on the limit to twine or eccentric between plunger 2 and seal element 3, thereby can suppress the wearing and tearing of plunger 2 and seal element 3 as much as possible.

Patent documentation 1: the spy opens flat 09-318611 communique

In constructing,, require the end sphere of plunger frame that very high sphericity is arranged, so manufacturing cost is very high in order to ensure rotating freely of plunger as above-mentioned plunger and being connected of slide block.And, after the plunger wear, be not only plunger and all must change, so maintenance cost is also very high with the plunger frame that plunger is fixed together.

Summary of the invention

The present invention In view of the foregoing proposes, and its purpose is, provides a kind of manufacturing cost, maintenance cost all more in the past than the liquid delivery pump for liquid chromatograph that reduced.

In order to address the above problem, the present invention makes the plunger frame with spheroid, and twists thereon and close the connection plunger.Promptly, apparatus of the present invention are a kind of liquid-feeding pumps, be equipped with and follow rotatablely moving of cam and reciprocating slide block, the front of plunger is inserted in the pump chamber by seal element and the base end side of plunger is connected to slide block and free to rotate, it is characterized in that, have spheroid with the end tabular surface butt of above-mentioned slide block at the connecting portion of above-mentioned slide block and above-mentioned plunger, on this spheroid, twist and close the base end side that connects above-mentioned plunger.

Because the manufacturing technology of high sphericity spheroid is very ripe in the manufacturing field of bearing etc., can make or buy high-quality, high sphericity spheroid cheaply, so, if adopt the present invention, then, can reduce cost by using such spheroid to make the plunger frame.And, not only can improve the degree of freedom of plunger motion, and,, can provide wearing quality compared with the past higher liquid delivery pump for liquid chromatograph so the wearing and tearing of seal element reduce owing to the distortion campaign that can follow seal element at aspect of performance.And, after plunger wear, only change plunger and get final product, so maintenance cost also is minimized.

Description of drawings

Fig. 1 is the figure of expression an embodiment of the invention.

Fig. 2 is the figure that represents an example of formation in the past.

Fig. 3 is the figure that represents the local detail of formation in the past.

Among the figure: 1-head, 2-plunger, 2a-external thread, 3-seal element, the 4-pump chamber, 5-suction inlet, 5a, 6a-non-return valve, the 6-escape hole, the 7-pump housing, 8-bearing, the 9-spring, 10-slide block, 10a-end tabular surface, the 11-cam, 12-Cam Follower, 15-plunger frame, 15a-end sphere, 15b-threaded hole, 16-thread ending cover.

Embodiment

An embodiment of the invention have been represented among Fig. 1.With what scheme expression is the part corresponding with Fig. 3, and therefore the integral body as liquid-feeding pump constitutes with Fig. 2 roughly the same.Among Fig. 1, the formation element identical with Fig. 3 function paid same symbol, so omitted repeat specification.

As shown in Figure 1, the plunger frame 15 in the present embodiment is a spheroid, and this is and in the past maximum difference.The technology of making high sphericity spheroid is very ripe in bearing manufacturing field, therefore, can create with lower cost, and, buy high-quality volume production product and also be easy to.On the spheroid of making like this or buying, process the threaded hole 15b that is provided with internal thread, as plunger frame 15.

The base end part of plunger 2 is provided with above-mentioned threaded hole 15b and twists the external thread 2a that closes, and therefore as shown by arrows, this part is screwed among the threaded hole 15b, thereby plunger 2 and plunger frame 15 are combined.

So the action of the present embodiment that constitutes is basic identical with example in the past shown in Figure 3, and the surface (sphere) and the structure that the end tabular surface 10a of slide block 10 contacts of the plunger frame 15 by spheroid can rotate freely plunger 2.For a change, can use the spheroid (for example bearing ball) of high sphericity to make plunger frame 15, therefore plunger 2 becomes more sliding suitable in the motion of angle direction, even having certain eccentric or distortion that ground also can not take place to twine, seal element shown in Figure 23 slides, consequently, the effect of

inhibition plunger

2 and 3 wearing and tearing of seal element is improved.

And, owing to combine by screw thread between plunger 2 and the plunger frame 15, so, can easily change plunger 2 after plunger 2 wearing and tearing.And, get final product because only change plunger 2, so can lower replacement cost than in the past.

And, above-mentioned expression be an embodiment of the invention, but the present invention is not limited in this embodiment.

Claims

1. liquid delivery pump for liquid chromatograph, it carries eluant by the to-and-fro movement of plunger in pump chamber, be equipped with and follow rotatablely moving of cam and reciprocating slide block, the front of above-mentioned plunger is inserted into the indoor and base end side above-mentioned plunger of said pump by seal element and is connected to above-mentioned slide block and free to rotate, it is characterized in that: have spheroid with the end tabular surface butt of above-mentioned slide block at the connecting portion of above-mentioned slide block and above-mentioned plunger, on this spheroid, twist and close the base end side that connects above-mentioned plunger.