JPH0481584A - Hydraulic pump - Google Patents

Abstract

PURPOSE:To protect a driving means as well as make a highly accurate flow rate securable by retreating a tube pressing member as far as the specified value at a time when such a force, being received as a reaction due to the tube pressure, has exceeded the specified value. CONSTITUTION:A liquid transferring tube 17 with elasticity is held between a tube pressing member 15 and a tube receiving part 13. Then, the tube 17 is gradually pressed by the tube pressing member 15 from the outside and thereby a pressure closing point is shifted to some extent, thus a liquid in the tube 17 is transferred. Here, when such a force that the tube pressing member 15 receives as a reaction due to pressure of the tube 17 has exceeded the specified value, the tube pressing member 15 is retreated as far as the specified value together with a base 25 in parallel with the tube 17 and in the opposite direction to the pressing direction. With this constitution, the force being received by the tube pressing member 15 is adjusted so as to be turned to the specified value at all times. Consequently, a highly accurate flow rate is thus securable without imposing an undue burden on a driving means including a motor 39 or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention particularly relates to a liquid pump used for liquids in the medical field such as infusions and blood transfusions. By moving the closing point,
The present invention relates to a liquid pump that transfers liquid within a tube.

[Prior Art] Conventionally, as shown in FIG. 3, for example, as shown in FIG. Can be opened and closed 1. ! Fi! 75 is closed, the closing parts 73 and 31
75, an elastic liquid transfer tube 79 is housed along the vertical direction, and a plurality of tubes protruding from inside the housing 71 toward the tube 79 are disposed vertically along the tube 79. The tube 79 is sandwiched between the finger-shaped tube pressing member 81 and the tube receiving portion 83 provided on the back side of the door 75, and each tube pressing member 81 is directed from the upstream side to the downstream side with respect to the tube 79. A device that transfers the liquid in the tube 79 by sequentially pressing the tubes 79 and moving the closing point of the tube 79 is known as a finger-type veli-curtic liquid pump.

Inside the housing 71, a cam shaft 89 that is rotationally driven by a motor 85 via an ohm gear 87 is provided with cams 91 in the same number as the tube pressing members 81 in the vertical direction.

The cams 91 are attached to the camshaft 89 so as to be shifted by a certain angle, and as the camshaft 89 rotates, each cam 91 is rotated with a shift, and accordingly, the tube pressing member 81 pushes the tube. It is configured to be pressed sequentially in the vertical direction.

On the other hand, the tube receiving part 83 is fixed to the leaf spring 93,
The leaf spring 93 is attached to the back surface of the door 75 via a spacer 95, one end of the leaf spring 93 is screwed, and a coil spring 97 is interposed between the other end and the spacer 95. are doing.

By the way, the diameter of the tube 79 has a tolerance of ±5 to 1 due to machining accuracy.
Since there is a 0% error and variation, the amount of reciprocating movement of the tube pressing member 81 is adjusted so that even if a tube with the smallest diameter within the error range is used, the tube pressing member 81 can be sufficiently compressed. It is set.

Therefore, if the diameter of the tube 79 is large, the force that the tube pressing member 81 receives as a reaction force increases beyond the allowable range when pressing the tube 79.
An excessive load is transmitted to the motor 85, causing inconvenience.

Furthermore, due to the processing accuracy of component parts such as the tube pressing member 81 and the cam 91, there is a dimensional error of about ±10%, and this dimensional error may cause the force that the tube pressing member 81 receives to become excessive.

Therefore, if the tube receiving part 83 is structured as described above and the force that the tube pressing member 81 receives as a reaction force increases beyond the allowable range, the tube receiving part 83
is moved backward in the direction in which the tube 79 is pressed against the repulsive force of the leaf spring 93, and the force received by the tube pressing member 81 is adjusted to prevent an excessive load from being applied to the motor 85.

[Problems to be Solved by the Invention] However, in the conventional liquid pump, when the tube receiving part 83 is retreated, the leaf spring 93 is centered around one end fixed with a screw, as shown by the chain line in FIG. Since the liquid flow path of the closed tube 79 is deformed into a rotational state as shown in FIG. However, there was a problem in that it affected the liquid feeding accuracy.

In addition, since the tube receiving part 83 is provided as a movable structure on the door 75, the structure of the installation part becomes complicated due to the narrow installation area, which may cause malfunction, and may cause chemical liquid etc. There have been problems in that maintenance work is not easy, such as wiping off when it gets stuck.

The present invention has been made in view of the above problems, and includes:
Even if there are variations in the diameter of the tube being pressed,
A liquid pump that does not transmit excessive reaction force to the drive means such as a motor through the tube pressing member, allows normal liquid delivery, and has a simplified structure on the tube receiving part that makes maintenance work easier. The purpose is to provide.

[Means for Solving the Problems] The present invention for solving the above-mentioned problems includes sandwiching an elastic liquid transfer tube between a plurality of tube pressing members and a tube receiving portion, and inserting the tube into the tube pressing member. A liquid pump that transfers liquid in a tube by sequentially pressing from the outside to move the closing point, the liquid pump having a tube receiving part and a plurality of tubes provided at positions facing the tube receiving part. a pressing member; a driving means for driving the tube pressing member; The liquid pump is comprised of an adjusting means for adjusting the force received by the tube pressing member by retracting it by a predetermined amount in a direction opposite to the pressing direction.

Further, the adjustment means includes an elastic body that biases the tube pressing member in the direction of pressing the tube with a predetermined biasing force;
a moving means that allows the tube pressing member to be parallel to the tube and move forward in the direction in which the tube is pressed or backward in a direction opposite to the direction in which the tube is pressed, and a reaction force that the tube pressing member receives; Preferably, the tube pressing member is configured to retreat by a predetermined amount against the biasing force of the elastic body when the force exceeds a predetermined value.

Further, by providing an interval adjusting means capable of regulating the movement of the tube pressing member in the forward movement direction by the moving means and adjusting the interval between the tube pressing member and the tube receiving part, the tube pressing member etc. are prevented from being worn out. Even in such a case, the distance between the tube pressing member and the tube receiving portion can be adjusted to a predetermined value, and the tube can always be pressed with a predetermined pressing force.

[Function] In the liquid pump of the present invention, even if the force that the tube pressing member receives as a reaction due to the pressure of the tube exceeds a predetermined value due to variations in the tube diameter, the tube pressing member , because the adjusting means causes the tube to move backward by a predetermined amount parallel to the tube and in the opposite direction to the suppressing direction, so the force received by the tube pressing member does not exceed the allowable range, and no unreasonable load is placed on the driving means such as the motor. It doesn't cost.

Therefore, the driving means is protected and a highly accurate flow rate can be obtained.

Moreover, since the structure of the tube receiving part side is simplified, maintenance work becomes easier.

[Examples] Hereinafter, the present invention will be described in detail based on illustrated examples.

FIG. 1 is a cutaway cross-sectional view of a main part of a liquid pump according to an embodiment of the present invention, and FIG. 2 is a cutaway perspective view of a main part showing how the liquid pump is used.

In the figure, reference numeral 1 denotes a case-like housing, the front part of which is closed with a closing plate 3, and a door 5 having a hollow interior is attached to the opening plate 3 so that it can be opened and closed by a door hinge 7. ing.

A door lock knob 9 is provided at the center of the right end of the door 5, and can be engaged with and detached from a knob receiving portion 11 formed on the closing plate 3.

A tube receiving part 13 is fixed to the center part of the back surface of the door 5, and a plurality of finger-shaped tube pressing members 1 are provided on the closing plate 3 side at positions facing the tube receiving part 13.
5, and an elastic liquid transfer tube 17 is sandwiched between the two along the vertical direction.

Note that the closing plate 3 opens at a location corresponding to the tube pressing member 15 , and a drip-proof rubber 19 is attached thereto by a holding frame member 21 . It is configured so that it can come into contact with the tube 17.

The drip-proof rubber 19 functions to prevent the tube pressing member 15 from being contaminated even if a chemical solution or the like accidentally leaks out of the tube.

Further, the closing plate 3 is formed with an accommodation groove 23 for guiding the tube 17 and aligning it in the vertical direction.

A plurality of tube pressing members 15 are arranged in the vertical direction along the tube 17, and a base 2 is provided in the housing 1.
It is attached to 5.

As shown in FIG. 2, the base 25 includes a back plate 27 and an upper plate 2.
9a and a lower plate 29b, the upper plate 29a and the lower plate 29b
A shaft 31 is disposed along the vertical direction between the two.

Each tube pressing member 15 is fitted into the shaft 31, so that each tube pressing member 15 individually and independently rotates around the shaft 31.
The convex portion 33 is configured to be able to press against the tube 17 while reciprocating.

The tube pressing member 1 is provided on the rear surface of the tube pressing member 15.
5 and the same number of cams 35 are engaged with each other, and these cams 35 are fitted onto a cam shaft 37 extending vertically between the upper plate 29a and the lower plate 29b.

Here, the adjacent cams 35 are attached to the cam shaft 37 at a predetermined angle, for example, in the case of 10 tube pressing members 15, they are shifted by 36 degrees.

A motor 39 is horizontally fixed to the rear surface of the back plate 27 of the base 25.

On the other hand, the camshaft 37 includes a worm 43 fitted to a motor shaft 41 facing the front side of the back plate 27, and a worm wheel 45 fitted to the upper end of the camshaft 37 protruding above the upper plate 29a. It is driven by a motor 39 via a worm gear consisting of a worm gear, and rotates to rotate each cam 35 at a predetermined angle.

In this way, the driving means for driving the tube pressing member 15 is configured.

Then, due to the rotation of the cam 35, each tube suppressing member 1
5 sequentially reciprocates and sequentially presses the tube 17 from above to below between it and the tube receiving portion 13 of the door 5.

Further, on both left and right sides of the back plate 27 of the base 25, guide members 49 having a guide hole 47 formed therein are protruded forward.

Further, a pair of protrusions 51 are formed at the left and right rear portions of the inner surface of the housing 1, and the ends of a pair of guide rods 53 that are inserted through the guide holes 47 are respectively fixed.

The outer diameter of the guide rod 53 is set to be slightly smaller than the inner diameter of the guide hole 47, and the base 25 moves along the guide rod 53.

That is, the tube pressing member 15 moves forward and backward parallel to the tube 17 and along the line X--X perpendicular to the axis of the tube 17.

Note that instead of using a rod rod like the guide rod 53, a plate-shaped flat guide may be used.

On the other hand, a linear bearing 55 is loaded into the guide hole 47 so that the guide rod 53 can slide smoothly.

The linear bearings 55 are arranged radially in three locations, for example, 120 degrees symmetrically when the guide rod 53 is viewed from the axial direction, and are loaded into grooves formed along the longitudinal direction of the guide rod 53, and act as bearings. is doing.

Note that the bearing is not limited to the above-mentioned linear bearing, but may also be a ball bearing, a roller bearing, a sliding bearing, an oil-impregnated bearing, or the like.

The above members constitute a moving means that allows the tube pressing member 15 to move parallel to the tube and move forward in the direction in which the tube is pressed or retreat in the opposite direction to the direction in which it is pressed.

Note that a coil spring 57 constituting an elastic body is fitted onto a portion of the guide rod 53 between the protruding portion 51 and the back plate 27 .

In this way, the adjusting means for adjusting the force applied to the tube pressing member 15 is configured, and when the force applied to the tube pressing member 15 as a reaction due to the pressing of the tube 17 exceeds a predetermined value, the coil spring 57 is The tube pressing member 15 pushes the tube 17 together with the base 25 against the force.
The tube pressing member 15 is adjusted so that the force received by the tube pressing member 15 is always a predetermined amount.

That is, the tube pressing member 15 is subjected to dimensional errors due to unavoidable diameter errors due to the machining accuracy of the tube 17 and dimensional errors due to dimensional errors due to the machining accuracy of component parts such as the tube pressing member 15 and the cam member 35. This prevents an increase in reaction force and prevents excessive load from being applied to the motor 35.

Note that the elastic body is not limited to the above-described coil spring 57, and a biasing means such as a leaf spring can be used.

Further, a stopper 59 is provided between the closing plate 3 and each front end surface of the upper plate 29a and lower plate 29b of the base 25 to prevent the base 25 from moving further from a predetermined position. It is being

The stopper 57 is configured such that the length of the stopper 57 protruding from the closing plate 3 can be varied by an adjustment screw 61 that threads through the closing plate 3.

Therefore, the stopper 57 and the adjusting screw 61 constitute a distance adjusting means for regulating the movement of the tube pressing member 15 in the advancing direction and adjusting the distance between the tube pressing member 15 and the tube receiving portion 13.

On the other hand, during operation, the cam member 35 and the tube pressing member 15
are constantly rubbing against each other, so if they wear out, there is a risk that they will not be able to press the tube 17 sufficiently. However, by adjusting the adjustment screw 61, the tube pressing member 15
The above problem can be solved by moving the tube closer toward the tube 17 by the amount of wear and adjusting the distance between the tube pressing member 15 and the tube receiving portion 13 to a predetermined value.

In addition, in the drawing, the upper plate 29a and the lower plate 2 of the base 25 are
Although a total of four stoppers 59, two for each stopper 9b, are provided, the present invention is not limited to this, and any stoppers 59 may be used as long as they can restrict the movement of the base 25 in the advancing direction. Not limited.

In addition, 63 in FIG. 2 indicates a container containing an infusion solution.

[Effects of the Invention] As detailed above, the liquid pump of the present invention has an elastic liquid transfer tube sandwiched between a plurality of tube pressing members and a tube receiving portion, and the tube is pushed by the tube pressing member. A liquid pump that transfers liquid in a tube by sequentially pressing from the outside and moving a closing point, which includes a tube receiving part and a plurality of tube pressers provided at positions facing the tube receiving part. a member, a driving means for driving the tube pressing member, and a driving means for driving the tube pressing member in parallel with and pressing the tube pressing member when the force that the tube pressing member receives as a reaction due to the pressing of the tube exceeds a predetermined value. and adjustment means for adjusting the force received by the tube pressing member by retracting the tube by a predetermined amount in the opposite direction.
Consists of a liquid pump.

Therefore, according to the liquid pump of the present invention, even if the force that the tube pressing member receives as a reaction due to the pressure of the tube exceeds a predetermined value due to variations in the tube diameter, the tube pressing member Because the adjustment means causes the tube to move back a predetermined amount parallel to the tube and in the opposite direction to the pressing direction, the force received by the tube pressing member does not exceed the permissible range (and prevents excessive loads from being applied to drive means such as motors). It doesn't cost.

Therefore, the driving means is protected and a highly accurate liquid feeding flow rate can be obtained.

Furthermore, since the structure of the tube receiving part side is simplified, maintenance work is simplified, such as wiping off any chemical liquid or the like that accidentally adheres to the tube.

Furthermore, the adjustment means includes an elastic body that biases the tube pressing member in the direction of pressing the tube with a predetermined biasing force;
a moving means that allows the tube pressing member to be parallel to the tube and move forward in a direction in which the tube is pressed or backward in a direction opposite to the direction in which the tube is pressed, and a reaction force that the tube pressing member receives; By configuring the tube pressing member to retreat by a predetermined amount against the biasing force of the elastic body when exceeds a predetermined value, the structure can be simplified and high durability can be obtained.

Further, by providing a distance adjusting means that restricts the tube pressing member from advancing beyond a predetermined position and can adjust the distance between the tube pressing member and the tube receiving portion, the tube pressing member and the driving means can be adjusted. Even if the tube is not sufficiently suppressed due to wear, the distance between the tube pressing member and the tube receiver can be adjusted and set to a predetermined value, ensuring that a predetermined pressing force is always applied to the tube. It is possible to achieve the effect that it can be applied.

FIG. 4 is a cross-sectional view showing a state in which a tube is closed by a conventional liquid pump.

(Explanation of symbols of main parts) 13...Tube receiving part 15.--Tube pressing member 25...Base 35...cam 39...Motor 47... Guide hole 53...Guide rod 57...Coil spring 59...stopper 61 -- Adjustment screw

[Brief explanation of drawings]

FIG. 1 is a cutaway cross-sectional view of a main part showing an embodiment of a liquid pump according to the present invention, FIG. 2 is a cutaway perspective view of a main part thereof,

Claims (3)

[Claims] (1) An elastic liquid transfer tube is sandwiched between a plurality of tube pressing members and a tube receiving portion, and the tubes are sequentially pressed from the outside by the tube pressing members to move the closing point. A liquid pump for transferring liquid in a tube, comprising: a tube receiving section; a plurality of tube pressing members provided at positions facing the tube receiving section; driving means for driving the tube pressing members; When the force that the tube pressing member receives as a reaction due to the pressing force exceeds a predetermined value, the tube pressing member is moved back by a predetermined amount in parallel to the tube and in a direction opposite to the pressing direction, and the tube pressing member is A liquid pump, comprising: an adjusting means for adjusting the applied force; (2) The adjustment means includes an elastic body that urges the tube pressing member in the direction of pressing the tube with a predetermined urging force, and the tube pressing member is parallel to the tube and advances in the direction of pressing the tube. or a moving means that allows the tube to retreat in the opposite direction to the pressing direction, and resists the biasing force of the elastic body when the reaction force received by the tube pressing member exceeds a predetermined value. 2. The liquid pump according to claim 1, wherein the tube pressing member is configured to retreat by a predetermined amount. (3) The tube pressing member according to claim 2, further comprising a distance adjusting means that prevents the tube pressing member from advancing beyond a predetermined position and can adjust the distance between the tube pressing member and the tube receiving portion. liquid pump.