CN104074700A - Liquid feeding pump - Google Patents

Abstract

The present invention provides a liquid delivery pump, in which, since the pressure on the syringe, liquid delivery tube, piston, and piping components connected thereto is relieved, the components are not easy to be worn out, and the frequency of replacing parts can be reduced. When multiple sets are arranged side by side, It is also possible to reduce the setting space. A liquid delivery pump, which has: a base plate (12), a syringe (16) is fixed on the upper part, and a notch groove (14) is formed on the lower part; a motor mounting plate (26); a motor (28), which is mounted on the motor mounting plate a plate; a rocking support member (30) that rockably supports the motor mounting plate with respect to the base plate; a cam (34) that is mounted to the rotation shaft of the motor; and a connecting member (36) that connects the piston and the cam. The cam is rotated by the motor, and the motor mounting plate is swung with the swing supporting part as the fulcrum. At the same time, the connecting part is moved up and down in the notch groove of the base plate to drive the piston to move up and down, and the liquid is sucked and ejected.

Description

Liquid delivery pump

technical field

The invention relates to a liquid delivery pump used in occasions such as adding quantitative medicine to sample liquid in instrumental analysis.

Background technique

Conventionally, a quantitative syringe pump shown in FIG. 5 is known as a liquid delivery pump for adding a quantitative drug to a sample liquid in instrumental analysis (see Patent Document 1). In the quantitative syringe pump of FIG. 5 , 202 denotes a base plate, 204 denotes a mounting plate, 206 denotes a syringe fixed to the mounting plate 204 , and 208 denotes a piston inserted into the syringe 206 from the rear end side of the syringe 206 . An O-ring is attached to the outer periphery of the front end portion of the piston 208 .

In FIG. 5 , 210 denotes a liquid delivery tube fixed to the mounting plate 204 . Check valves 212 and 214 are respectively installed on both ends of the liquid delivery pipe 210 in the axial direction, and at the same time, the front end side of the syringe 206 is connected to the middle part in the axial direction. for connectivity.

In FIG. 5 , 216 denotes a rotating plate rotatably attached to the base plate 202 via a shaft 218 . A predetermined portion on the rear end side of the plunger 208 protruding from the syringe 206 is connected to an eccentric position of the rotary plate 216 away from the rotation center 220 via a connecting member 222 . The rotating plate 216 is rotated by the rotation of a shaft 218 of a motor mounted on the back surface of the base plate 202 .

In the fixed-dose syringe pump of this example, the mounting plate 204 is rotatably attached to the base plate 202 via the shaft 226, and the syringe 206 is provided so as to be pendulum-movable with a fulcrum 228 near its distal end. Further, by rotating the rotary plate 216 by a motor, the rear end side of the piston 208 protruding from the syringe 206 is circularly moved to drive the piston 208 to reciprocate.

In the metered injection pump of this example, first, from the most advanced state of the piston 208 shown in FIG. The imaginary circle 230 shown makes a circular motion, and the piston 208 retreats. At this time, although the piston 208 is in an inclined state due to the circular motion of the rear end side, since the syringe 206 can perform a pendulum motion near its front end side as a fulcrum, as shown in Figure 6, when the piston 208 is inclined, correspondingly, the syringe 206 is also tilted by the pendulum motion, which does not interfere with the reciprocating motion of piston 208. Then, the piston 208 shown in FIG. 7 is in the most backward state, and the rotating plate 216 continues to rotate, and the piston 208 shown in FIG. 5 returns to the most forward state. After that, by the rotation of the rotary plate 216, the above-described motion is repeated.

In the fixed-dose syringe pump of this example, when the piston 208 is retracted by performing the above-mentioned movement, the medicine is sucked into the syringe 206 from the axial end side of the liquid delivery pipe 210 through the suction tube 234 , for example, from the medicine tank 232 . Further, when the piston 208 is advanced, the medicine in the syringe 206 is ejected from the other axial end side of the liquid supply pipe 210 to, for example, the sample liquid in the reaction tank 238 through the ejection pipe 236 .

prior art literature

Patent Document 1: Japanese Laid-Open Patent Application No. 2004-92563

Contents of the invention

The problem to be solved by the invention

However, the pump described in conventional Patent Document 1 shown in FIG. 5 has the following problems.

(1) Since the pump described in Patent Document 1 adopts a structure in which the syringe swings, the syringe, liquid delivery tube, piston, and piping components connected thereto (suction tube, discharge tube, pipe joint, check valve of the liquid delivery tube, etc.) O-rings of valves, pistons, etc.) are under pressure, which is easy to cause loss of components. In addition, since components are easily worn out, the frequency of replacing components increases.

(2) Among the pumps described in Patent Document 1, if a plurality of pumps are arranged side by side (for example, 2 to 4 units are arranged side by side), it is necessary to prevent the piping parts of adjacent pumps from coming into contact with each other due to the movement of piping parts such as pipes. And mutual interference, it is necessary to prepare a larger setting space.

The present invention is made in view of the above background, and its object is to provide a liquid delivery pump, in which, since the pressure on the syringe, liquid delivery tube, piston, and piping components connected thereto is relieved, the parts are not easy to be worn out, and not only the replacement parts can be reduced. frequency, and when multiple units are set side by side, the setting space can also be reduced.

solutions to problems

In order to achieve the above objectives, the present invention provides a liquid delivery pump, characterized in that,

It has:

syringe,

a plunger, which is inserted into the syringe from the rear end side of the syringe,

The liquid delivery pipe is equipped with a check valve or a switch valve on both ends of the axial direction, and at the same time, the front end side of the syringe is connected to the middle part of the axial direction,

The base plate has the syringe fixed on the upper front side in the vertical direction, the liquid delivery tube fixed on the upper front side in the left-right direction, and a notch groove formed in the lower part in the vertical direction,

a motor mounting plate, which is disposed behind the base plate,

a motor, which has a rotating shaft, is mounted to the motor mounting plate,

a swing support member connected to an upper portion of the base plate and an upper portion of the motor mounting plate to swingably support the motor mounting plate relative to the base plate,

a cam, which is mounted on the rotating shaft of the motor,

and a connecting part, which connects the rear end side of the piston and the part of the cam away from the installation position of the motor rotation shaft, and is inserted into the notch groove of the base plate;

Wherein, by rotating the rotating shaft of the motor to drive the cam to rotate, the motor mounting plate is made to swing with the central axis of the swing supporting part as a fulcrum, and at the same time, the connecting part is placed in the notch of the base plate The up and down movement in the groove drives the piston to move up and down. When the piston is moved back, the liquid is sucked into the syringe from one axial end of the liquid delivery tube. When the piston is advanced, the liquid is drawn from the other axial end of the liquid delivery tube. The liquid in the syringe spurts out.

In the present invention, in the state where the syringe and the liquid delivery tube are mounted on the base plate, the cam is driven to rotate by rotating the rotation shaft of the motor, so that the motor mounting plate is swung around the central axis of the swing support member as a fulcrum, and at the same time, the connecting member Moving up and down drives the piston to move up and down. That is, in the present invention, the cam converts the rotational motion of the rotary shaft of the motor into the rocking motion of the motor mounting plate and the vertical motion (reciprocating motion) of the piston. Therefore, in the present invention, during liquid delivery, the motor mounting plate swings, and the syringe, liquid delivery tube, and piston do not swing, so it is difficult to apply pressure to the syringe, liquid delivery tube, piston, and piping components connected thereto.

The effect of the invention

The liquid delivery pump of the present invention has the following effects.

(a) Due to the structure that the syringe, liquid delivery tube and piston do not swing, it is not easy to feed the syringe, liquid delivery tube, piston and the piping parts connected to it (suction tube, discharge tube, pipe joint, stopper of the liquid delivery tube). return valve, O-ring of the piston, etc.) to apply pressure, and the parts are not easily worn out. In addition, since parts are less prone to wear and tear, the frequency of replacing parts can be reduced.

(b) When multiple units are installed side by side (for example, 2 to 4 units are installed side by side), piping components such as pipes do not move, and the piping of adjacent pumps does not interfere with each other. Therefore, the degree of freedom in installation is increased, and side-by-side installation can be reduced in size. Installation space required for multiple units.

Description of drawings

Fig. 1 is a partially cutaway schematic front view showing an example of a liquid delivery pump of the present invention.

FIG. 2 is a schematic side view, partially in section, of the pump of FIG. 1 .

Fig. 3 is a view explaining the movement of a piston and a motor mounting plate of the pump shown in Fig. 1 .

4 is a diagram showing a state in which a plurality of pumps are arranged side by side, (A) is a front view, and (B) is a plan view.

Fig. 5 is a partially cutaway schematic front view showing an example of a conventional liquid sending pump.

Fig. 6 is a view explaining the operation of the syringe and the piston of the pump of Fig. 5 .

Fig. 7 is a view explaining the operation of the syringe and the piston of the pump of Fig. 5 .

Explanation of reference signs

10 liquid delivery pump

12 Substrate

14 notched slot

16 syringes

18 pistons

20 liquid delivery tube

22, 24 check valve

26 motor mount version

28 motor

30 swing support parts

31 pivot

32 motor shaft

34 cam

36 Connection parts

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially sectional schematic front view showing an example of the liquid delivery pump of the present invention, and FIG. 2 is a partially sectional schematic side view.

In the liquid delivery pump 10 of this example, 12 denotes a vertically rectangular metal base plate with notched grooves 14 formed in the lower part along the vertical direction, and 16 denotes a fixing member (not shown) on the upper front side of the base plate 12 along the vertical direction. A fixed synthetic resin syringe 18 represents a synthetic resin plunger inserted into the syringe 16 from the rear end side of the syringe 16 . The substrate 12 is fixed to a detection device main body (not shown). The notch groove 14 is cut so that the upper end is semicircular and the lower part is rectangular. In addition, the vertical length of the notch groove 14 is formed to be larger than the stroke length of the piston 16 which will be described later.

Reference numeral 20 in the figure denotes a liquid-feeding tube made of synthetic resin, which is fixed to the upper front side of the substrate 12 in the left-right direction by a fixing member (not shown). Check valves 22, 24 are respectively installed on both ends of the axial direction of the liquid delivery pipe 20. At the same time, the front end side of the syringe 16 is connected to the middle part of the axial direction. The inside of the liquid delivery pipe 20 and the inside of the syringe 16 are mutually connected. In addition, the liquid feeding tube 20 is integrally connected to the syringe 16 in a substantially T-shape.

Reference numeral 26 in the figure denotes a vertically rectangular metal motor mounting plate, which is provided behind the base plate 12 . On the back surface of the motor mounting plate 26, a motor 28 is fixed. In addition, the upper portion of the base plate 12 and the upper portion of the motor mounting plate 26 are connected by a swing support member 30 , and the motor mounting plate 26 is supported by the swing support member 30 so as to be swingable relative to the base plate 12 . The structure of the swing support member 30 is not limited, for example, it may be a structure composed of a rotating shaft fixed to one of the base plate 12 and the motor mounting plate 26, and a bearing fixed to the other of the two. .

A cam 34 in the shape of a rectangular plate is fixed to the rotating shaft 32 of the motor 28 . In addition, the rear end side of the piston 18 is connected to the portion of the cam 34 away from the mounting position of the motor rotation shaft by a connecting member 36 inserted into the cutout groove 14 of the base plate 12 . The structure of the connecting member 36 is not limited, for example, a cylindrical connecting pin whose both ends are rotatably mounted to the cam 34 and the piston 18 may be used.

In the liquid delivery pump 10 of this example, the cam 34 is driven to rotate by the rotating shaft 32 of the rotating motor 28, so that the motor mounting plate 26 is swung with the central axis of the swing supporting member 30 as the fulcrum 31, and at the same time, the connecting member 36 is The up and down movement in the notch groove 14 drives the piston 18 to move up and down. When the piston 18 is retreated, the liquid is sucked into the syringe 16 from the axial end side of the liquid delivery pipe 20. When the piston 18 is advanced, the liquid is sucked from the liquid delivery pipe. The other end side in the axial direction of 20 ejects the liquid in the syringe 16 .

Referring to Fig. 3, the operation of the pump 10 of the above-mentioned present example will be described. In the following description, the position of the rotating shaft 32 of the motor 28 (hereinafter referred to as “motor rotating shaft 32 ”) is referred to as A, the position of the connection member 36 is referred to as B, and the line connecting A and B is referred to as L. In addition, in FIGS. 3( b ) to ( h ), the reference signs of the respective components are omitted.

(1) From the state where the piston 18 is at the top dead center, that is, the state where A is at the bottom, B is at the top, and L is vertical (Fig. 3(a)), the motor rotation shaft 32 starts to rotate counterclockwise (viewed from the front), and the cam 34 It also begins to rotate counterclockwise with A as the axis (Fig. 3(b)). At this time, the connecting member 36 moves downward while contacting the left inner surface of the cutout groove 14 of the base plate 12 , so that the piston 18 is pulled toward the bottom dead center. At the same time, the motor mounting plate 26 swings to the right (viewed from the front) about the fulcrum 31 (central axis of the swing support member 30 ) as an axis. When the connecting member 36 moves downward until L is in a horizontal state, the rightward swing of the motor mounting plate 26 is maximized ( FIG. 3( c )).

(2) When the cam 34 continues to rotate, the connecting part 36 moves downward in the notch 14 (Fig. 3(d)). When A is at the top, B is at the bottom, and L is vertical, the piston 18 reaches the bottom dead center (Fig. 3(d) e)). At this time, the motor mounting plate 26 swings to the left (viewed from the front) around the fulcrum 31 and returns to its original position.

(3) When the cam 34 continues to rotate counterclockwise, the connecting member 36 moves upward while contacting the right side of the notched groove 14 of the base plate 12, so the piston 18 is pushed toward the top dead center (Fig. 3(f)) . At the same time, the motor mounting plate 26 swings leftward (viewed from the front) about the fulcrum 31 . When the connecting member 36 moves upward until L is in a horizontal state, the leftward swing of the motor mounting plate 26 is maximized ( FIG. 3( g )).

(4) The cam 34 continues to rotate, and the connecting part 36 moves upward in the notch 14 (Fig. 3(h)). When A is at the bottom, B is at the top, and L is vertical, the piston 18 reaches the top dead center (Fig. 3 (a)). At this time, the motor mounting plate 26 swings to the right (viewed from the front) around the fulcrum 31 and returns to its original position.

In the pump 10 of this example, since the length of the up-down direction of the notch groove 14 is formed to be greater than the stroke length of the piston 16, as mentioned above, when the connecting member 36 moves up and down in the notch groove 14, the connecting member 36 will not move from the notch groove. 14 break away.

In the liquid delivery pump 10 of this example, when the piston 18 is retracted by performing the above-mentioned movement, the medicine is sucked into the syringe 16 from, for example, the medicine tank 40 through the suction tube 42 from one axial end side of the liquid delivery tube 20 . Further, when the piston 18 is advanced, the medicine in the syringe 16 is ejected from the other axial end side of the liquid supply pipe 20 to, for example, the sample liquid in the reaction tank 46 through the ejection pipe 44 .

At this time, by adjusting the size of the circular motion of the connecting member 36, specifically, by adjusting the position where the connecting member 36 is mounted on the cam 34, the stroke length of the piston 16 can be adjusted, that is, the suction volume and ejection of the liquid can be adjusted. quantity.

In addition, in the liquid sending pump 10 of this example, as shown in FIG. It does not matter if they are in contact, but by placing the liquid delivery pump 10 obliquely (looking down), the degree of freedom of installation is increased, and the width (installation space) 50 when a plurality of them are arranged side by side can be reduced. The parallel arrangement of three pumps in this example can be used, for example, in an analytical instrument using three kinds of chemicals.

In addition, the present invention is not limited to the above-mentioned embodiments. For example, in the above embodiment, check valves are respectively installed on both ends of the liquid delivery pipe in the axial direction. In fact, an on-off valve can be used instead of the check valve, and the on-off valve is opened or closed at a specified time. In addition, micro switches or optical switches can also be used to detect the specified position of the motor mounting plate or connecting parts, and open or close the switch valve according to the detection signal. Also, the direction of rotation of the motor may be any direction.

Claims (3)

1. A liquid delivery pump, characterized in that, It has: syringe, a plunger, which is inserted into the syringe from the rear end side of the syringe, The liquid delivery pipe is equipped with a check valve or a switch valve on both ends of the axial direction, and at the same time, the front end side of the syringe is connected to the middle part of the axial direction, The base plate has the syringe fixed on the upper front side in the vertical direction, the liquid delivery tube fixed on the upper front side in the left-right direction, and a notch groove formed in the lower part in the vertical direction, a motor mounting plate, which is disposed behind the base plate, a motor, which has a rotating shaft, is mounted to the motor mounting plate, a swing support member connected to an upper portion of the base plate and an upper portion of the motor mounting plate to swingably support the motor mounting plate relative to the base plate, a cam, which is mounted on the rotating shaft of the motor, and a connecting part, which connects the rear end side of the piston and the part of the cam away from the installation position of the motor rotation shaft, and is inserted into the notch groove of the base plate; Wherein, by rotating the rotating shaft of the motor to drive the cam to rotate, the motor mounting plate is made to swing with the central axis of the swing supporting part as a fulcrum, and at the same time, the connecting part is placed in the notch of the base plate The up and down movement in the groove drives the piston to move up and down. When the piston is moved back, the liquid is sucked into the syringe from one axial end of the liquid delivery tube. When the piston is advanced, the liquid is drawn from the other axial end of the liquid delivery tube. The liquid in the syringe spurts out. 2 . The liquid delivery pump according to claim 1 , wherein the vertical length of the notch groove is longer than the stroke length of the piston. 3 . 3. The liquid delivery pump according to claim 1 or 2, wherein the stroke length of the piston is adjusted by adjusting the position where the connecting member is mounted on the cam.