JPH021502Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a spring return type high-pressure micrometer metering pump for analytical equipment, particularly high-performance liquid chromatography equipment.

(Prior Art) A conventional spring return type high-pressure micrometer metering pump, that is, a mechanically driven reciprocating pump, has a cylinder 1 of a sleeve 1, as shown in an exploded perspective view in FIG.
A plunger 3 is attached to the tip of a spindle 2 that is reciprocably provided in a, and a spring receiver 2 at the rear end is attached.
A return spring 4 is compressed between the sleeve 1 and the outer peripheral step 1b of the sleeve 1, and the pump head 5 is inserted into a pair of bolts 1c implanted at the tip of the sleeve 1.
is removably fixed with a nut 6. This pump head 5 is attached to the sleeve 1 in a liquid-tight and air-tight manner with a seal retainer 7 and an O-ring 8, and the tip of the plunger 3 passes through a pump seal 9 installed inside the pump head 5 to open a liquid passage 10 inside the pump head 5. is coming.

A suction side nipple 11 connected to a solvent bottle is attached to the lower part of the pump head 5, and a discharge side nipple 13 for attaching a tube 12 communicating with a column (not shown) is attached to the upper part. and,
The spindle 2 is reciprocated by a cam rotated by a motor (not shown) and a return spring 4, and the plunger 3 moves in and out of the liquid passage 10, and the nipple 1
Suction valves and discharge valves (not shown) provided in 1 and 13 are opened and closed alternately.

If a mechanically driven reciprocating pump configured as described above is used for a long time, the pump seal 9 will be damaged due to the reciprocating motion of the plunger 3, and the sealing performance will be impaired, requiring replacement. removes the nut 6, removes the pump head 5 from the sleeve 1, and replaces the pump seal 9, but a special jig is required to assemble the seal 9 into the pump head 5, and if you are inexperienced, you may damage the seal at this time. Or, when attaching the pump head to the sleeve 1, the plunger 3 is recessed into the cylinder 1a, which is extremely difficult and the seal may be damaged in the process of inserting the plunger. This resulted in an impact on quantitative performance.

(Purpose of the invention) The present invention was made against the background of the above points, and it is an object of the present invention to facilitate replacement of the pump seal without impairing quantitative performance by removing the spindle together with the pump head while fixed to the sleeve. It is in.

(Structure of the invention) In order to achieve the above object, the present invention has a plunger attached to the tip of a spindle that is reciprocably provided in a cylinder of a sleeve that is removably fixed to the machine frame, and a plunger is attached to the tip of a spindle that is reciprocally movable inside a cylinder of a sleeve that is removably fixed to the machine frame. A return spring is compressed between the sleeve and the outer circumferential step, and the tip of the plunger faces a liquid passage in a pump head that is removably fixed to the sleeve.
In a pump for an analyzer that opens and closes a valve in a liquid passage by reciprocating the plunger, a pin hole penetrating through the cylinder of the sleeve is formed, and a lock corresponding to the pin hole is formed in the spindle when the return spring is compressed. The spindle is characterized in that a recess is formed, and a locking pin is inserted through the pin hole and the locking recess so that the spindle can be fixed to the sleeve.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

A motor 21 is attached to the upper part of the machine frame 20, and a cam 22 is fixed to its output shaft 21a. A sleeve 23 is removably attached to the side of the machine frame 20 with bolts 24, and a spindle 25 is attached to the cylinder 23a of the sleeve 23.
is provided so that it can move back and forth.

A plunger 26 is provided at the tip of the spindle 25 so as to protrude from a plunger setter 25a.
A spring receiver 27 is fixed to the outer periphery of the rear end, and a return spring 28 is compressed between the spring receiver 27 and the stepped portion 23b of the sleeve 23, and a cam surface of the cam 22 and the cam surface of the cam 22 are attached to the rear end of the spindle 25. An abutting bearing 29 is provided.

A pump head mounting opening 23c having a larger diameter than the cylinder 23a is formed at the tip of the sleeve 23. A seal retainer 30 is fitted into the large diameter portion 23d at the front of the opening 23c, and the pump head 31 is fitted into the seal retainer 30. It is mounted in a liquid-tight and air-tight manner via an O-ring 32. Plunger insertion hole 30 bored in the seal holder 30 and pump head 31
The plunger 26 is inserted through the pistons a and 31a, and its tip faces the liquid passage 31b of the pump head 31. This plunger 26 has a plunger insertion hole 31
In a, the pump seal 33 fitted in the insertion hole 31a is inserted to prevent the sample from leaking from the liquid passage 31b.

A suction valve 35 is installed at the lower valve seat 34a of the liquid passage 31b.
A discharge valve 35b is installed in the upper valve seat 34b so that it can be seated, a solvent bottle 38 is attached to a nipple 36a provided at the lower opening of the liquid passage 31b via an air trap 37, and a solvent bottle 38 is attached to the nipple 36a provided at the lower opening of the liquid passage 31b. A tube 39 communicating with a column (not shown) is connected to the nipple 36b. And cam 2
2, the spindle 25 is pushed and the plunger 2
6 protrudes into the liquid passage 31b, the suction valve 35
a is seated on the valve seat 34a, and the discharge valve 35b is seated on the valve seat 34a.
The cam 22 further rotates, the spindle 25 is moved back by the return spring 28, the plunger 26 escapes from the liquid passage 31b, and the suction valve 35
a is opened, the discharge valve 35b is closed, and the solvent bottle 3
8 is filled into the liquid passage 31b. By this reciprocating movement of the plunger 26, the solvent in the solvent bottle 38 is sequentially supplied to the column.

A pair of pin holes 40 passing through the opening 23c are formed in the outer peripheral wall of the sleeve 23 from the top to the bottom. Then, the plunger setter 25a of the spindle 25 is moved so that the spindle 25 is pushed by the cam surface of the cam 22 and the return spring 28 is compressed to the maximum, that is, the plunger setter 25a of the spindle 25 is aligned with the pin hole 40 near the top dead center of the pump. A locking recess 41 in the form of an annular groove is formed on the outer periphery of the U-shaped locking pin 4.
Both legs 42a of the two legs 23 and 25 can be inserted into the pin hole 40 from above and engaged with the locking recess 41, thereby fixing both legs 23 and 25 integrally.

Therefore, if the pump seal 33 deteriorates,
As mentioned above, the sleeve 23 is secured by the U-shaped locking pin 42.
When the bolt 24 is removed with the and spindle 25 locked together, both 23 and 25 are removed from the machine frame 20 as a unit. In this state, the seal retainer 30 and pump head 31 can be removed from the sleeve 23, and the return Since the pump seal 33 and other sealing members can be replaced with the spring 28 compressed, when it is reassembled to the machine frame 20, it can be easily attached with the bolts 24 in this state. In this embodiment, the locking recess 41 is formed on the outer periphery of the plunger setter 25a fixed to the tip of the spindle 25, but it may also be provided on the spindle 25 or a component fixed thereto. In addition to the groove shape, 41 can also be a hole-shaped recess.

(Effects of the invention) As described above, this invention has a structure in which the spindle, which is biased by the return spring, is integrally locked to the sleeve by the locking pin when the sleeve is removed from the machine frame. , the sleeve and spindle can be attached to and removed from the machine frame as one unit, and the user can return the machine frame in this state to the manufacturer, where the manufacturer will replace the pump seal etc. and perform other maintenance, and the user can reinstall the machine frame in this state. Once installed, the locking pin can be removed and the pump can be restarted. Therefore, it is possible to prevent damage to the sealing material when assembling it and to prevent it from affecting the quantitative performance of the pump, and it is not necessary to compress the return spring when assembling the sleeve, making assembly easy.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a conventional spring return type high pressure micrometer metering pump, Figure 2 is a sectional front view of a spring return type high pressure micrometer metering pump showing an embodiment of the present invention, and Figure 3 is a side view. Fourth
The figure is also a - sectional view of FIG. 2. 20 is a machine frame, 21 is a motor, 22 is a cam, 23 is a sleeve, 25 is a spindle, 25a is a plunger setter, 26 is a plunger, 28 is a return spring, 31 is a pump head, 40 is a pin hole,
41 is a locking recess, and 42 is a locking pin.

Claims (1)

[Scope of utility model registration request] A plunger is attached to the tip of a spindle that is reciprocally provided within the cylinder of a sleeve that is removably fixed to the machine frame, and a return spring is compressed between the spring receiver at the rear end and the outer peripheral step of the sleeve. , a pump for an analyzer in which the tip of the plunger faces a liquid passage in a pump head removably fixed to a sleeve, and the plunger opens and closes a valve in the liquid passage by reciprocating movement of the plunger, which penetrates the cylinder of the sleeve. At the same time, a locking recess is formed in the spindle that corresponds to the pin hole when the return spring is compressed, and a locking pin is inserted through the pin hole and the locking recess to fix the spindle to the sleeve. A pump for analytical equipment that is characterized by the following: