JP2011214539A - Micropump - Google Patents

Abstract

To provide a degree of freedom in the arrangement of tubes for transporting liquid.
A tube for flowing a liquid, a rotating cam, and a plurality of fingers slidably held between the tube and the cam, wherein the plurality of fingers include at least one curved finger. And a tube guide frame that holds the tube from a side opposite to a side where the plurality of fingers come into contact, and the cam rotates to cause the plurality of fingers to flow through the liquid. A micropump that is sequentially closed from an inlet portion toward a discharge port portion to cause the liquid in the tube to flow.
[Selection] Figure 2

Description

  The present invention relates to a micropump.

An apparatus is disclosed in which a plurality of fingers are arranged on the outer periphery of a cam, and the tips of the fingers sequentially push the tube to transport the liquid in the tube (Patent Document 1).

JP-A-9-532729

However, in the case of the apparatus having the configuration disclosed in Patent Document 1, the arrangement of the tubes is limited. That is, in such a device, the tube must be arranged so that the center of the cam and the center of the arc extending from the tube are substantially the same. Therefore, it is desirable to provide flexibility in the arrangement of the tubes.
This invention is made | formed in view of such a situation, and it aims at giving freedom degree to arrangement | positioning of the tube which conveys a liquid.

The main invention for achieving the above object is:
A tube for flowing liquid;
A rotating cam,
A plurality of fingers slidably held between the tube and the cam, the plurality of fingers including at least one curved finger;
A tube guide frame for holding the tube from a side facing the side on which the plurality of fingers contact;
With
When the cam rotates, the plurality of fingers sequentially closes the tube from the liquid inlet portion toward the discharge port portion, and causes the liquid in the tube to flow.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

It is a perspective view which shows schematic structure of the micropump in 1st Embodiment. It is a top view of tube unit 11 of the micro pump concerning a 1st embodiment. It is a fragmentary sectional view of tube unit 11 in a 1st embodiment. It is BB sectional drawing in FIG. 4 is a plan view of the tube unit 11 after the rotation of the flat groove cam 20. It is a figure explaining the motion of the finger in a reference example. It is a schematic perspective view of the tube unit 11 in 2nd Embodiment.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

A tube for flowing liquid;
A rotating cam,
A plurality of fingers slidably held between the tube and the cam, the plurality of fingers including at least one curved finger;
A tube guide frame for holding the tube from a side facing the side on which the plurality of fingers contact;
With
By rotating the cam, the plurality of fingers sequentially close the tube between the fingers and the tube guide frame from the liquid inlet portion toward the discharge port portion. A micro pump that allows liquid to flow.
By doing in this way, the freedom degree can be given to arrangement | positioning of the tube which conveys a liquid.

In this micropump, it is preferable that the plurality of fingers bend in a direction toward a central finger of the plurality of fingers arranged in a row. Preferably, at least one of the plurality of fingers is a linear finger, and the fingers other than the linear finger are each curved in a direction toward the linear finger. The cam is a flat groove cam in which a cam groove is formed in a plane of a rotating rotating plate, and includes a plurality of guide pins slidably disposed in the cam groove, It is desirable that a plurality of fingers be attached. In addition, it is preferable that the tips of the fingers are bonded at a contact surface with the tube, and the tube and the guide frame of the tube are bonded at a side opposite to a side where the plurality of fingers contact.

The finger is preferably an elastic body. Further, it is desirable that the tube is disposed at a position where a surface including a central axis of the tube is parallel to a surface of a rotating plate constituting the cam. Further, it is desirable that the tube is disposed at a position where a surface including a central axis of the tube intersects a surface of a rotating plate constituting the cam.

By doing in this way, the freedom degree can be given to arrangement | positioning of the tube which conveys a liquid.

=== First Embodiment ===
FIG. 1 is a perspective view showing a schematic configuration of the micropump in the first embodiment. In FIG. 1, the micropump 10 includes a tube unit 11, a control unit 12, and a coupling member 13 that couples the tube unit 11 and the control unit 12. The tube unit 11 includes a tube 50, a plurality of fingers (not shown) that press the tube 50, and the tube 50. The control unit 12 includes a motor as a driving source, a driving force transmission mechanism that transmits a driving force to the camshaft, and a control circuit unit that controls driving of the motor (none of which are shown). ing. Tube 5 in this embodiment
0 may not be an elastic body as long as it can be deformed by a finger described later. For example, a tube formed of a vinyl material may be used.

The tube 50 attached to the tube unit 11 has an inlet 52 for inflowing liquid from a reservoir (not shown) for storing the liquid, and an outlet 53 for discharging, and each protrudes from the tube unit 11. It is installed. A reservoir may be provided inside the tube unit 11 and connected to the inlet 52 in the tube unit 11. The tube unit 11 and the control unit 12 are stacked and closely fixed by the coupling member 13. Therefore, the micropump 10 includes the inlet portion 52 and the outlet portion 5 of the tube 50.
The interior other than 3 has a waterproof structure.

FIG. 2 is a plan view of the tube unit 11 of the micropump according to the first embodiment.
FIG. 3 is a partial cross-sectional view of the tube unit 11 in the first embodiment. 4 is similar to FIG.
It is BB sectional drawing in.

The tube unit 11 has a space for accommodating the flat groove cam 20 and the cam holding frame 65 in a substantially central portion. The tube unit 11 includes a planar groove cam 20 and a plurality of fingers 4.
1 to 48 (in FIG. 3, the finger 44 is exemplified) and a plurality of guide pins 31 to 38 (in FIG. 4, the guide pin 34 is exemplified). Further, the tube unit 11 includes a tube 50.
Including a part of A part of the flat groove cam 20, a plurality of fingers (figure 3 illustrates the fingers 44) swung by the flat groove cam 20, and a tube 50 pressed by the plurality of fingers includes a tube guide frame. 15 and the second guide frame 16 are held by a guide frame 14.

The cam shaft 76 including the flat groove cam 20 is pivotally supported by the cam holding frame 65 on the upper side of the shaft and the machine frame 17 on the lower side of the shaft. The cam holding frame 65 is fixed to the machine frame 17. The cam shaft 76 is rotated in a direction to be described later (counterclockwise as viewed from above) by a drive mechanism 70 including a motor (not shown).

The tube 50 is held in a tube guide groove 51 provided by the tube guide frame 15 and the second guide frame 16. The tube guide groove 51 is provided with a tube guide wall 52 that regulates the position of the tube 50 in the swinging direction of the fingers. A portion of the tube guide wall 52 that is in contact with the tube 50 is bonded.

The tube 50 and the plurality of fingers are respectively connected to the tube guide frame 15 and the second guide frame 16.
The tube guide frame 15 and the second guide frame 16 are fixed to each other by welding or fixing screws in the state where they are mounted inside the tube guide groove 51 and the finger guide groove 56 formed on the tube unit 11.

A cam groove 21 is formed in the flat groove cam 20. FIG. 2 shows a virtual inner circle 25a and a virtual outer circle 25b. The axes of these circles coincide with the rotation axis of the planar groove cam 20.
The virtual inner circle 25a is a circle that is in contact with the portion of the cam groove 21 that is closest to the center of the planar groove cam 20. The virtual outer circle 25b is a circle that is in contact with the center of the flat groove cam 20 of the cam groove 21 that is farthest from the center. In this description, it may be expressed as “low” when close to the center of the flat groove cam 20, and “high” when far from the center of the flat groove cam 20. For example, the virtual outer circle 25b is higher than the virtual inner circle 25a.

When viewed clockwise, the shape of the cam groove 21 starts from a height that is in contact with the lower virtual inner circle 25a and gradually increases toward the virtual outer circle 25b. And the virtual outer circle 25b
The height is lowered to a position where it abruptly contacts the virtual inner circle 25a. In this way, the height gradually increases from the height of the virtual inner circle 25a to the height of the virtual outer circle 25b.
The cam groove 21 is formed in the flat groove cam 20 so that the structure of sudden lowering is repeated four times.

The cam groove 21 is provided with a protruding portion 22 for a projection 34a to be described later. In this way, the finger 44 has a structure that is difficult to come off from the cam groove 21.

Next, the finger will be described. The tube unit 11 of the present embodiment includes a plurality of fingers 41 to 48. In these fingers 41 to 48, all the fingers except the finger 44 are formed to be curved. The fingers 41 to 43 are curved so as to be bent in a direction toward the straight fingers 44. Also, fingers 45-4
8 also curves toward the straight fingers 44. These fingers 41-48
Has main body portions 41 a to 48 a and front end portions 41 b to 48 b which are the front ends of the main body portions 41 a to 48 a and are bonded to the tube 50.

The radii of curvature of the fingers 41 to 48 formed so as to be curved are the tip portions 41b to 4b.
The radius of curvature is such that 8b contacts the tube 50 substantially perpendicularly. By doing in this way, the burden concerning the tube 50 can be reduced so that it may mention later.

Guide pins 31 to 38 are formed integrally with the fingers 41 to 48. The guide pins 31 to 38 are pins that can rotate around the vertical direction with respect to the surface of the planar groove cam 20.
The guide pin 34 is provided with a protrusion 34 a for preventing the guide pin 34 from coming off the cam groove 21.

Moreover, as shown in FIG. 4, the cross-sectional shape of the finger 44 is a rectangular shape. The cross-sectional shape of the finger guide groove 56 formed by the finger guide walls 57 of the tube guide frame 15 and the second guide frame 16 is also rectangular. Since it has such a structure, the finger 44 does not rotate around its axis. For this reason, the guide pin 34 is prevented from being detached from the cam groove 21.

The fingers 41 to 48 can slide and advance in the corresponding finger guide grooves 56. Each of the finger guide grooves 56 has a shape having the same radius of curvature as that of the curved fingers.

Since it has such a structure, when the flat groove cam 20 rotates, the fingers 44 are
It swings according to the shape of the cam groove 21. Further, the distal end portion 44 b is bonded at the contact portion of the tube 50. Therefore, even if the tube 50 is a tube that does not have elastic force, the tube 50 is crushed or expanded in accordance with the swinging finger 44. That is, even when the tube 50 (tube lacking elastic force) that does not easily return to its original shape is used, the liquid in the tube 50 can be transported appropriately.

FIG. 5 is a plan view of the tube unit 11 after the planar groove cam 20 is rotated. Here, transportation of the liquid using the above-described tube unit 11 will be described with reference to FIG. 5 and FIG. 2 described above.

In FIG. 2, the planar groove cam 20 is rotated via a drive mechanism 70 including a motor (shown in the direction of arrow L). The finger 44 moves along the cam groove 21 of the rotating planar groove cam 20. Then, the finger 44 slides along the finger guide groove 56.

The positions of the guide pins 31 to 37 from the finger 41 to the finger 47 are determined by the planar groove cam 20.
The position is gradually higher in the clockwise direction. In the figure, fingers 41 to 47 are also shown.
It is shown that the positions of the front end portions 41b to 48b are gradually higher from the center of the flat groove cam 20. That is, the tube 5 moves from the finger 41 to the finger 47.
0 is crushed more. Specifically, the fingers 46 and 47 squeeze and close the tube 50 almost completely. On the other hand, the finger 41 has just started to crush the tube 50 and has just started to close.

On the other hand, the guide pin 38 of the finger 48 is at the lowest position in the cam groove 21.
Since the tip 48b of the finger 48 is also bonded to the tube 50, the finger 48
When the guide pin 38 falls into the lowest position of the cam groove 21, the tube 50 is expanded. Therefore, the tube 50 is in a state in which the cross section of the tube 50 is most expanded at the tip 48b of the finger 48.

When the planar groove cam 20 is further rotated in the direction of the arrow L from this position (FIG. 5), the cam groove 21
Thus, the height of the position of each finger is changed. Thereby, finger 44,
45 squeezes and closes the tube 50. On the other hand, the fingers 46 and 47 closing the tube 50 in FIG. 2 expand the flow path of the tube 50. Then, the liquid flows into the position where the flow path is enlarged.

Thus, the finger 41 to the finger 48 are connected to the fingers 41, 42, 43, 4
The tubes 50 are sequentially pushed in the order of 4, and the tubes 50 are sequentially formed from the fingers that block the tubes 50.
Expand the flow path. And the obstruction | occlusion is cancelled | released in an order from the finger which completed obstruction | occlusion. At this time, by using a structure in which any of the fingers always closes the tube 50, backflow can be prevented in transporting the liquid.

Further, by adopting the configuration as in the present embodiment, the center of the cam 20 and the center of the arc extending from the tube are allowed to be shifted from each other. That is, in this embodiment,
A degree of freedom can be given to the arrangement of the tubes 50.

FIG. 6 is a diagram for explaining the movement of the finger in the reference example. In the drawing, two fingers 144 and 145 are schematically shown as fingers of the reference example. The fingers 144 and 145 in the reference example are not curved but are linear fingers. And
The two fingers 144 and 145 are guided by linear finger position regulating walls 157, respectively.

In such a configuration of the reference example, if the finger is moved to a low position, the distance between the tip portions 144b and 145b of these two fingers is W1. On the other hand,
When the fingers 144 and 145 move to a high position, the distance between the tip portions 144b and 145b of these two fingers is W2. Finger tips 144b, 145b
However, when the distance between the tip portions changes depending on the position of the finger, a force for moving the finger tip in the longitudinal direction of the tube is applied. If it is assumed that the finger tips 144b, 145b do not slip relative to the tube, the tube will be deformed in its longitudinal direction. On the other hand, if it is assumed that the finger tips 144b and 145b slide on the tube, the tube is caused to generate a frictional force in its longitudinal direction. That is, in any situation, the tube is burdened by the fingers 144 and 145.

On the other hand, according to the above-described embodiment, the fingers 41 to 48 are respectively connected to the tube 5.
Nearly perpendicular to the 0 plane. By doing in this way, the burden with respect to the tube as shown in the reference example can be reduced.

=== Second Embodiment ===
FIG. 7 is a schematic perspective view of the tube unit 11 in the second embodiment. In the figure, the cam 220, the tube 250, the fingers 241 to 247, and the finger position regulating members 257-1 to 257-7 are shown. The fingers 241 to 247 are formed of a deformable elastic body, for example. ing. The fingers 241 to 247 have tip portions 241b to 24 that contact the tube 250, respectively.
7b is provided. The fingers 241 to 247 are provided with rear end portions 241c to 247c that come into contact with the cam 220, respectively.

The finger position regulating members 257-1 to 257-7 are tubular members that communicate with each other. Each finger position regulating member is formed in a curved shape. The finger position regulating members 257-1 to 257-7 are fixed at predetermined positions in the tube unit 11, respectively. The corresponding fingers pass through the inside of the finger position regulating members 257-1 to 257-7. Since the fingers 241 to 247 are elastic bodies, the finger position regulating members guide each finger in a predetermined direction.

In the first embodiment described above, the tube 50 is disposed at a position parallel to the surface of the cam 20, whereas in the second embodiment, the tube 250 is disposed at a position intersecting the surface of the cam 220. . That is, in the tube unit 11 in the second embodiment, the directions of the tube 250 and the cam shaft 276 are the same. In this way, the finger position regulating members 257-1 to 257 can be arranged so that the direction intersecting the surface of the cam 220 is the longitudinal direction of the tube.
˜7 is curved.

Next, the shape of the cam 220 will be described. The figure shows a virtual inner circle 225a and a virtual outer circle 22
5b is shown. The axes of these circles coincide with the cam shaft 276. Virtual circle 225a
Is a circle in contact with the lowest part of the cam 220. The virtual outer circle 225b is a circle that is in contact with the highest portion of the cam 220.

The shape of the surface with which the rear end portions 241c to 247c of the fingers abut starts from the height of the virtual inner circle 225a and gradually increases toward the virtual outer circle 225b when viewed in the direction opposite to the rotation direction of the cam 220. The height is getting higher. Then, when it comes into contact with the virtual outer circle 225b, its height is rapidly lowered to a position where it comes into contact with the virtual inner circle 225a. Thus, the virtual inner circle 225
The outer shape of the cam 220 is formed so that the structure of gradually increasing from the height of a to the height of the virtual outer circle 225b and then suddenly lowering is repeated six times.

In such a configuration, when the cam 220 is rotated in the direction of the arrow in the figure, the tube 250 is gradually closed from the finger 241 to the finger 247. in this way,
Since the finger is configured to be bent, the arrangement of the tube 250 can be given a degree of freedom. Moreover, since the front-end | tip part of a finger can be made to contact perpendicularly to the tube 250, it also has the advantage that the burden concerning the tube 250 can be reduced.

The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

10 micropump,
11 Tube unit, 12 Control unit,
13 coupling member, 14 guide frame,
15 tube guide frame, 16 second guide frame, 17 machine frame,
21 Cam groove, 25a Virtual inner circle, 25b Virtual outer circle,
31-38 guide pins, 41-48 fingers,
51 Tube guide groove, 52 Tube guide wall,
56 finger guide groove, 57 finger guide wall,
65 Cam holding frame, 76 Cam shaft

Claims (8)

A tube for flowing liquid;
A rotating cam,
A plurality of fingers slidably held between the tube and the cam, the plurality of fingers including at least one curved finger;
A tube guide frame for holding the tube from a side facing the side on which the plurality of fingers contact;
With
The micro pump in which the plurality of fingers sequentially closes the tube from the liquid inflow port portion toward the discharge port portion and causes the liquid in the tube to flow by rotating the cam. The micropump according to claim 1, wherein the plurality of fingers are each curved in a direction toward a central finger of the plurality of fingers arranged side by side. 3. The micro of claim 1, wherein at least one of the plurality of fingers is a linear finger, and fingers other than the linear finger are each curved in a direction toward the linear finger. pump. The cam is a flat groove cam in which a cam groove is formed in the plane of a rotating rotating plate,
A plurality of guide pins slidably disposed in the cam groove;
The micropump according to claim 1, wherein the plurality of fingers are attached to the plurality of guide pins. The tip of the finger is bonded at the contact surface with the tube,
The micropump according to any one of claims 1 to 4, wherein the tube and the guide frame of the tube are bonded on a side opposite to a side where the plurality of fingers contact.   The micro pump according to claim 1, wherein the finger is an elastic body. The micropump according to claim 6, wherein the tube is disposed at a position where a surface including a central axis of the tube is parallel to a surface of a plate constituting the cam. The micropump according to claim 6, wherein the tube is disposed at a position where a surface including a central axis of the tube intersects a surface of a rotating plate constituting the cam.

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