JPH0354384A - Liquid transfusion pump - Google Patents

Abstract

PURPOSE:To reduce the cost of manufacture with a driving load decreased by providing a fixed part, fixed in a condition separated from a finger, and a pair of connecting members, rotatably supported with one end to the finger and the other end to the fixed part, in a side part of each finger, in a supporting means. CONSTITUTION:In the case of moving a tube 14 with a maximum pressing amount, since a finger 2012 of the tube is restricted so as to be reciprocation- moved only along a pressing direction A by a supporting mechanism 24, the tube 14 is surely pressed with the maximum pressing amount by the finger 2012. In the supporting mechanism 24 thus constituted, since the finger 2012 is only connected so as to constitute so-called parallelogram by two connecting members 3212, 3412, an area of sliding parts in the two connecting members 3212, 3412 is generated extremely small, as a result, friction resistance, generated at the time of sliding, is small suppressed. Thus being possible to small set generated torque in a driving motor 38, the reduction of power consumption and manufacturing cost can be attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an infusion pump equipped with a finger drive mechanism that presses a tube provided for liquid delivery, and particularly to an infusion pump in which the fingers always have a constant trajectory. The present invention relates to a finger-type infusion pump equipped with a drive mechanism that moves the finger-type infusion pump.

[Prior Art] Conventionally, as shown in FIG. 5, a finger-type infusion pump a has a plurality of fingers C that press a tube b along the extending direction of the tube b, that is, the liquid feeding direction. We are prepared. On the other hand, these many fingers C are configured to be driven to reciprocate along the direction in which the tube b is pressed by the corresponding cam d, and these cams d are driven to move back and forth in the direction in which the tube b is pressed by the corresponding cam d. It is set to gradually increase in size. In this way, by rotating the drive shaft e to which a number of cams d are fixed in common, a number of fingers C are dynamically driven based on the eccentric movement of the cam d, and the tube b The liquid inside is
The liquid will be pushed out and delivered along the direction of movement.

[Problems to be Solved by the Invention] In such a conventional infusion pump a, a predetermined finger C reliably reciprocates along the direction in which the tube b is pressed based on the eccentric rotation movement of the corresponding cam d. In order to restrict the movement of each finger C, guide members f are provided on both sides of each finger C along the direction of reciprocating movement, and both sides of the finger C are slidably supported by these guide members f. As a result, the moving direction of each finger C is restricted to a certain direction that presses the tube b.

However, although each finger C is slidable on both sides by the guide member f, it is supported by surface contact, so frictional resistance inevitably exists between each finger C and the guide member f. This frictional resistance becomes a load on the motor that rotationally drives the cam d, causing problems such as poor drive and large consumption of electric power.

In particular, in the past, in order to reduce this frictional resistance,
If the contact area is set small, the direction of movement of the finger C will no longer be fixed in a fixed direction, making it impossible to achieve the original purpose, and a reasonably large contact area is essential.

In addition, the above-mentioned frictional resistance varies depending on the assembly accuracy and processing accuracy of the guide member f, so even if the frictional resistance is large, it is possible to ensure that the finger C
In order to drive the motor back and forth, the capacity of the motor must be set large, which poses the problem of increasing costs. Furthermore, it has been pointed out that the guide surface of the guide member f and both side surfaces of the fingers C must be smoothly finished over a wide area, which increases the processing cost.

This invention was made in view of the above-mentioned problems, and an object of the invention is to set the frictional resistance as small as possible in the finger support system, reduce the driving load on the drive source for moving the fingers, and An object of the present invention is to provide an infusion pump that can achieve low manufacturing costs.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the purpose, an infusion pump according to the present invention has a pump that presses a tube in which the liquid to be delivered is filled, so that the infusion pump moves in the liquid delivery direction. a plurality of fingers disposed along the tube; a supporting means connected to each finger and supporting the corresponding finger so as to move back and forth along a pressing direction in which the tube is pressed; driving means for driving the tube to move along the pressing direction so as to sequentially press the fingers along the liquid feeding direction; The device is characterized in that it includes a fixing portion fixed in the fixed state, and at least a pair of connecting members having one end pivotally supported by the finger and the other end pivotally supported by the fixing portion.

Further, in the infusion pump according to the present invention, the connecting member is characterized in that the shaft support between one end of the connecting member and the finger and/or the shaft support between the other end and the fixed portion are rotatable.

Further, in the infusion pump according to the present invention, both the connecting members are arranged parallel to each other and have the same length.

Further, in the infusion pump according to the present invention, each of the connecting members is rotatably fitted into a hole formed in the finger at one end, and fitted into a hole formed in the fixed part at the other end. It is characterized by being fitted so that it can rotate freely.

[Function] Since the infusion pump according to the present invention is configured as described above, each finger is supported so as to reciprocate along the direction in which the tube is pressed by only the corresponding pair of connecting members. become. As a result, the sliding part is
There is only a pivoting part at one end of the finger and both connecting members, and a pivoting part at the other end of the fixed part and both connecting members, and the sliding area is extremely small, resulting in less friction when the fingers move. Resistance will also be reduced.

[Embodiment] Below, the structure of an embodiment of an infusion pump according to the present invention will be described in detail with reference to FIGS. 1 to 4 of the accompanying drawings.

As shown in FIG. 1, the infusion pump 10 of this embodiment includes a casing 12 and a tube that is attached to the casing 12 and is filled with liquid to be delivered. 14, and a liquid feeding mechanism l6 that feeds the liquid in the tube 14 from the bottom to the top. Here, the front surface (the front side in the illustrated state) of the housing 12 is open, and this front opening is completely closed by the tube mounting plate 18. The above-mentioned tube 14 is attached to the inner surface of the tube mounting plate 18 so as to extend in the vertical direction, for example, with both upper and lower ends of the portion located inside the housing 12 being locked. There is.

On the other hand, the above-mentioned liquid feeding mechanism 16 has a plurality of fingers 20, - 20, (12 in this embodiment) along the extending direction of the tube L4, as shown in FIG. They are stacked one on top of the other in order from top to bottom. here,
These fingers 20, - 20.2 are formed from horizontally extending plate-like members, and are arranged independently of each other so as to be freely slidable in the horizontal plane in the direction of pressing the tube l4. .

Note that the finger 20 located at the lowest position. The underside of? , is in sliding contact with the upper surface of the lower guide member 22a, and the upper surface of the finger 2012 located at the uppermost side is in sliding contact with the upper surface of the lower guide member 22b.
It is in sliding contact with the bottom surface of.

These lower guide member 22a and upper guide member 22b are
As shown in FIG. 3, they are connected to each other by a connecting member 22c. In this way, the fingers 20, to 201.
A stacked body of will be defined.

Here, in the following description, each finger 20. ~20
12 are formed in the same shape, and when each finger is a theme, a subscript ~1■ is added to the code 20 to identify each finger, and when the shape of each finger is a theme, It is expressed only by the reference numeral 20 without a subscript.

In addition, this liquid feeding mechanism 16 moves each finger 20 in a direction in which the tube 14 is pressed independently, that is, along a pressing direction indicated by arrow 8, which is orthogonal to the extending direction of the tube 14. A support mechanism 24 is provided to support the device so that it can only move. In this support mechanism 24, each finger 20 is formed with a pair of planar circular through holes 26a and 26b which are vertically penetrated and spaced apart by a predetermined distance along the suppression direction A. Further, these through holes 26a and 26b extend in the lateral direction (that is, a direction perpendicular to the suppression direction A in a horizontal plane) and are connected through communication passages 26c and 26d, respectively, which are set slightly narrower than their diameters. , is open on the right side of the finger 20.

On the other hand, this support mechanism 24 is fixed on the bottom of the housing 12 at approximately the same height as the stack of fingers 20 on the right side in the illustrated state. A fixed block 28 is provided. A pair of planar circular through holes 30a and 30b are formed in the fixed block 28, passing through in the vertical direction and spaced apart by the above-mentioned predetermined distance along an axis parallel to the above-mentioned pressing direction A. There is. These through holes 30a, 30b extend laterally and are connected to communicating paths 30c, 3 which are set slightly narrower than their diameters.
They are opened on the left side surface of the fixed block 28 through the respective holes 0d.

This support mechanism 24 has each finger 201 to 20
, ■ and the fixed block 28 are provided with twelve pairs of connecting members 321 to 321■, 34, to 341■.

Here, one of the connecting members 321 to 32I2 is a substantially circular shape having an outer circumferential surface slidingly in contact with an inner circumferential surface of one of the through holes 26a of the corresponding fingers 201 to 20I2. It is integrally constituted by one end, a substantially circular other end having an outer peripheral surface that slides on the inner peripheral surface of one of the through holes 30a of the fixed block 28, and a connecting piece that connects these both ends. . In other words, each one of the connecting members 321 to 32, 2 is rotatably supported at both ends by the corresponding fingers 20, to 20, 2 and the fixed block 28, respectively. Here, this connecting piece is formed to have a width narrower than the width of the communicating passages 26c and 30c described above.

Further, the other connecting member 34, ~3412 has one end portion of a substantially circular shape having an outer peripheral surface that slides in contact with the inner peripheral surface of the other through hole 26b of the corresponding finger 20, ~20l2, and one end portion of the other connecting member 34, ~3412 of the fixed block 28. The other end of the substantially circular shape having the outer circumferential surface that slides on the inner circumferential surface of the through hole 30b and the connecting piece that connects these both ends are integrally formed? It is configured. In other words, each other connecting member 341 to 34, 2 is connected to the corresponding finger 2.
0. ~20l2 and the fixed block 28, which are rotatably supported at both ends. Here, this connecting piece is formed to have a width narrower than the width of the communication passages 26d and 30d described above.

Here, these one and other connecting members 321 to 32,
．． , 34. .about.34,, are set to have the same length. As a result, each pair of connecting members 321 to
321 ■. 34■ to 34■ constitute a so-called parallelogram, and each finger 20. ~20, ■ will be regulated to reciprocate only along the pressing direction A.

Here, in this embodiment, each finger 20, .
201■, each connecting member 32, - 32. ．． ．． ? 41-34
1 and the fixed block 28 are made of Duracon. In this way, each connecting member 321 to 32
12; In the shaft support portions 341 to 341■, the shaft can be supported with a sufficiently small coefficient of friction by direct sliding contact without intervening a separate bearing.

Further, the connecting members 32, - 32, 2, 34. ～34■ is
The fingers 201-20■ can be locked to the fixed block 28 using a leaf spring or the like. In this case, the connecting members 321-321■, 341-341■ are connected to the fingers 20. 20,2 and the fixed block 28 do not need to be rotatably supported at both ends.

In addition, the above-mentioned liquid feeder side 16 has these fingers 201.
~ 201■ To move back and forth in a catlike manner? motive horizontal 36
It is equipped with This drive mechanism 36 includes a drive motor 38 having a motor shaft 38a that is rotationally driven around an axis parallel to the pressing direction A, a worm gear 40 coaxially fixed to the motor shaft 38a, and a worm gear 4o.
A worm wheel 42 is engaged with the worm wheel 42 and rotatably supported around a vertical axis, a drive shaft 44 is coaxially fixed to the worm wheel 42, and the above-mentioned fingers 20. It is configured with eccentric disc cams 46 and 461, which are attached in correspondence with 2ol2.

Here, these eccentric disk cams 461 to 46 are configured to fit into recesses formed in the rear portions of the corresponding fingers 20 and 2o12. Further, the front end surface and the rear end surface of this recessed portion are formed by corresponding eccentric disc cams 46, - 46.
.

Furthermore, these two eccentric disc cams 46, - 46, 2 are connected to the corresponding fingers 20. - The amount of movement along the pressing direction A of 2012 is gradually changed from bottom to top along the extending direction of the tube l4, and periodically changed so as to return to the original state after rotating 360 degrees. As shown in FIG.
The direction in which the hour is indicated is 0 degrees, and the angle (measured clockwise) is specified to change in 30 degree increments.

In this way, in this drive mechanism 36, the drive shaft 44 is rotationally driven in the clockwise direction as the drive motor 38 is started, so that the fingers 20, to 20l
．． are driven to move dynamically as a whole, and the liquid in the tube 14 that is pressed by them is fed from the bottom to the top.

That is, if we pay attention to the 20 fingers located at the top,
As shown in FIG. 1, an eccentric disc cam 46 is in contact with this
．． When the eccentric phase angle of No. 2 is 90 degrees, it is set to exactly half the total pressing amount of the tube 14. In addition, as shown in FIG. 4, when the eccentric phase angle is O degrees, this finger 20.2
4 is pressed with the maximum amount of pressure.

In other words, when the eccentric disc cam 2012 corresponding to this finger 2012 is at an eccentric phase angle of 90 degrees as shown in FIG. is the 0 degree finger) is the 9th code from the bottom, 20. The finger that presses the tube 14 with the minimum amount of pressure (that is, the finger with an eccentric phase angle of 180 degrees) is the finger 204, which is the sixth finger from the bottom.

As described above with reference to FIG. 4, when the eccentric disc cam 46 corresponding to this finger 20 moves the tube 14 with the maximum pressing amount with the eccentric phase angle being O degrees, this finger 20 Pressing direction A by support mechanism 24
It is regulated to only move back and forth along the
The fingers 20 ensure that the tube 14 is pressed with the maximum amount of pressure.

That is, in this embodiment, such a support mechanism 2
4, the finger 20 has two connecting members 32.3
4, they are only connected to form a so-called parallelogram, so the area of the sliding portion of the two connecting members 32 and 34 is extremely small, and as a result,
The frictional resistance that occurs during sliding can be kept small. In this manner, according to this embodiment, it is possible to set the torque generated by the drive motor 38 to be small, thereby achieving reductions in power consumption and manufacturing costs.

In addition, in this embodiment, the area of the shaft support is reduced and it is supported on a curved surface, so even if assembly accuracy or processing accuracy is poor, the shaft support state is maintained and it slides on a flat surface. The so-called stuck state (locked state during movement) that may occur when supporting is effectively suppressed.

Furthermore, in this embodiment, since the area of the sliding part is reduced, the processing cost for finishing the sliding part smoothly can be reduced, and in this way, the overall manufacturing cost can be reduced. will be made into

It goes without saying that this invention is not limited to the configuration of the embodiments described above, and can be modified in various ways without departing from the gist of the invention.

For example, in the embodiment described above, each finger 2
0 r~20,. , each connecting member 32, - 32, 2; 34
, ~34l2, and the fixed block 28 have been described as being made of Duracon, but the present invention is not limited to this structure and may be made of any material. Here, if the selected material has poor lubricity, a separate shaft supporting member such as a bearing will be employed.

Further, in the above-described embodiment, the support mechanism 24 that supports the finger 20 so as to reciprocate only in the pressing direction is provided only on one side (right side) of the finger 20. The present invention is not limited to such a configuration, and may be configured to be disposed on both sides of the finger 20.

[Effect of the invention 1 As detailed above, the infusion pump according to the present invention has the following effects:
A plurality of fingers arranged along the liquid feeding direction in order to press the tube whose inside is filled with the liquid to be fed;
a support means connected to each finger and supporting the corresponding finger so as to move back and forth along a pressing direction in which the tube is pressed; driving means for moving and driving the tube along the pressing direction so as to sequentially press the tube; The device is characterized in that it includes at least a pair of connecting members, each of which is pivotally supported by a finger, and the other end of which is pivotally supported by a fixed portion.

Further, in the infusion pump according to the present invention, the connecting member is characterized in that the shaft support between one end of the connecting member and the finger and/or the shaft support between the other end and the fixed portion are rotatable.

Further, in the infusion pump according to the present invention, both the connecting members are arranged parallel to each other and have the same length.

Further, in the infusion pump according to the present invention, each of the connecting members is rotatably fitted into a hole formed in the finger at one end, and fitted into a hole formed in the fixed part at the other end. It is characterized by being fitted so that it can rotate freely.

Therefore, according to the present invention, the frictional resistance is set to be as small as possible in the finger support system, and the driving load on the drive source for moving the fingers is reduced.
An infusion pump that can achieve low manufacturing costs will be provided.

[Brief explanation of drawings]

FIG. 1 is a plan sectional view showing the configuration of an embodiment of the infusion pump according to the present invention with the upper and lower guide members removed; FIG. 2 shows the internal structure of the infusion pump shown in FIG.
Figure 3 is a vertical cross-sectional view of the internal structure of the infusion pump shown in Figure 1, cut along line III--III; Figure 4 is a vertical cross-sectional view of the internal structure of the infusion pump shown in Figure 1; A plan view showing a state in which the tube is pressed the most; and FIG. 5 is a plan view showing the configuration of a conventional infusion pump. ? 0... Infusion pump, 12... Housing, 14... Tube, 16... Liquid feeding mechanism, 18... Tube mounting plate, 20 (20, ~20.2)... Finger,
2 2 a =-lower guide member, 22b...upper guide member, 22c...connection member, 2 4-...support mechanism,
26a; 26b: 30a; 30b-through hole, 26c;
26d: 30c. 30d...Communication path, 32 (3
2. ~3 2. ．． ) ・34 (34, ~34..
)... Connection member, 36... Drive mechanism, 38... Drive motor, 38a... Motor shaft, 40... Worm gear, 42... Worm wheel, 44... Drive shaft, 461- 46l■...Eccentric disk cam.・+ Figure 3 X (14 24 Figure 4

Claims (4)

[Claims] (1) In order to press the tube whose inside is filled with the liquid to be sent, a plurality of fingers are arranged along the liquid sending direction, and the corresponding finger is connected to each finger and presses the tube. a support means for supporting the tube so as to reciprocate along the pressing direction; and driving the tube to move along the pressing direction so as to sequentially press the fingers supported by the supporting means along the liquid feeding direction. The support means includes a fixed part fixed to a side of each finger in a state spaced from the fixed part, one end of which is pivotally supported by the finger, and the other end of which is pivotally supported by the fixed part. An infusion pump comprising at least one pair of connecting members. (2) The infusion solution according to claim 1, wherein the connecting member is configured such that an axial support between one end and the finger and/or an axial support between the other end and the fixed part are rotatable. pump. (3) The infusion pump according to claim 1, wherein both the connecting members are arranged parallel to each other and have the same length. (4) Each of the connecting members has one end rotatably fitted into a hole formed in the finger, and the other end rotatably fitted into a hole formed in the fixed part. The infusion pump according to claim 1, characterized in that: