JPH0617018Y2 - Elastic tube feeder in elastic tube pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an elastic tube pump, and more particularly, to an elastic tube pump, in order to prevent the failure of liquid transfer due to repeated compression stress of a pressure roller and fatigue. The present invention relates to an elastic tube feed device in an elastic tube pump that delivers a tube at a speed substantially equal to the transfer speed of the elastic tube and always has a constant infusion rate.

2. Description of the Related Art An elastic tube pump transfers a fluid conducted to an elastic tube by sequentially pressing the fluid in a section of the elastic tube in a transfer direction. In the point of transferring a fluid, mainly a liquid, through the elastic tube. Since it has the characteristic of not destroying biological cells, its use in medical fields such as artificial dialysis and biotechnology has become popular.
Since the elastic tube is easily compressed due to repeated compression in the same section and reliability becomes low in long-term use, the elastic tube has been replaced with a new elastic tube after a certain driving time.

In order to solve the above-mentioned problems, the present applicant paid attention to the fact that the elastic tube is clamped and used in a stationary state in order to prevent the elastic tube from moving in the driving direction due to driving friction during driving. It has been proposed to release the clamp and move the elastic tube to the above-mentioned one section to move to a new tube portion after a considerable time when the tube is fatigued.

FIG. 3 is a block diagram for explaining an example of the elastic tube pump previously proposed by the present applicant, in which 1 is an elastic tube pump, which is a circular pressing groove 12 formed in the main body 11. Cylindrical body 1 which rotates concentrically around the rotation axis 13
4 are provided, and a plurality of pressing rollers 15 of the same size and of planetary rotation are provided on the outer periphery of the cylindrical body. An elastic tube 16 is inserted between the pressing roller 15 and the pressing groove 12. The rotary shaft 13 is joined to a drive shaft 23 by a motor 21 via a speed reduction mechanism 22 and rotated.
When the cylindrical body 14 rotates in the arrow R direction, the liquid on the source side 161 that communicates with the source liquid (not shown) is pumped toward the outflow side 162. At this time, a force in the rotational direction is applied to the elastic tube 16 by the frictional force between the elastic tube 16 and the pressing roller 15, and this force overcomes the frictional force with the pressing groove 12 so that the elastic tube 16 moves in the direction of the arrow V. Move to. Reference numeral 30 denotes a known clamper, which clamps the elastic tube 16 by clamp pieces 31 and 32 to prevent the elastic tube 16 from moving.

Between the clamper 30 and the elastic tube pump 1,
A movement detector 40 is provided, and the elastic tube 16 is movably sandwiched by the detection rollers 43 and 44, and the rotation of the detection rollers is detected to detect the movement of the elastic tube 16. Reference numeral 24 is a first timer, and the timer 24 is a predetermined time after the motor 21 rotates, specifically,
The time when the elastic tube 16 starts to fatigue is set to, for example, 500 hours. Reference numeral 25 denotes a second timer, which starts its operation after the set time of the first timer 24, and moves the elastic tube 16 to the clamper 30 when the elastic tube 16 is opened so that the unused portion reaches the pressing groove 12 at a time ΔT. set. A drive circuit 33 is a circuit for energizing the coil 36 of the clamper 30 for ΔT time. The discriminator 50 operates the elastic tube 16 during the ΔT time when the clamper 30 is opened.
Is a permissible range, it is “good”, outside the permissible range, that is, the elastic tube 16 does not move accurately, or stops. In the case of moving without doing, the "no" lamp is turned on.

Problems of the prior art The above-mentioned elastic tube pump has a problem of reliability deterioration, which is a defect caused by fatigue of the elastic tube in a use section of the elastic tube, and the new elastic tube is moved by moving the unused elastic tube. The reliability can be improved by re-driving as described above, and since it can be used over almost the entire length of the elastic tube, highly reliable and low cost infusion operation can be performed, but the elastic tube clamp is removed and moved. In this case, since the relative moving speed between the pressing roller 15 and the elastic tube 16 becomes small, the liquid transfer amount becomes small accordingly, which causes an error. Further, there is another problem that the clamp mechanism becomes complicated and expensive.

Means for Solving Problems The present invention has been made to solve the above problems, and is approximately equal to the moving speed of the elastic tube 16 when the elastic tube 16 is pressed by the pressing roller 15. The purpose of the present invention is to provide a tube feeding device that solves the fatigue problem of the elastic tube by feeding at a constant speed, and that makes the infusion volume always constant. At least two of the two intervals
Elasticity for pressing the inner surface of the pressing groove 12 at one point to seal the liquid in the elastic tube, and a motor for rotating the pressing roller in one direction to inject the liquid through the elastic tube. The tube pump has a feed reduction mechanism that reduces the rotation of the motor, and a rotation transmission mechanism that is driven by the reduction mechanism and that transmits rotation to a feed roller that sandwiches the elastic tube and feeds it out. An elastic tube feeding device for an elastic tube pump, wherein the elastic tube is fed at a speed substantially equal to the moving speed of the elastic tube.

Embodiment FIG. 1 is a block diagram for explaining an embodiment of the present invention, which is a block diagram showing an elastic tube feeding device of the present invention in which an elastic tube moving speed V ₂ is constant. ,
The same components as those of the conventional example shown in FIG. In FIG. 1, when the elastic tube 16 is pressed and driven by the pressing roller 15 on the pressing groove 12, the liquid in the elastic tube 16 is pressed and sealed by at least two pressing rollers 15 in the section of the pressing groove 12 and is driven in the driving direction. Is infused into. At this time, a component force in the driving direction of the pressing roller 15 acts on the elastic tube 16. On the other hand, since there is a pressing force on the pressing groove 12 due to the pressing of the pressing roller 15, if there is no friction between the pressing groove 12 and the elastic tube 16, the elastic tube 16 is driven by the driving direction component force.
Moves. However, since there is friction, it moves at a low speed V ₂ that balances this frictional force. When the pressing speed of the elastic tube is V ₁ and the cross-sectional area is S, the infusion volume Q of the elastic tube pump is represented by Q = (V ₁ −V ₂ ) · K · S (1). The value of K is a coefficient that represents the ratio of the actual transfusion amount to the theoretical transfusion amount that is generated when the elastic tube is pressed and deformed by the pressing roller, and is determined by the pump, but a value of about 0.7 is the measured value. Is required as. For example, inner diameter 1.58 mm x wall thickness 0.81
mm, the outer diameter of rotation on the outer circumference of the pressing roller was 64 mm, and the number of rotations was 16 rpm, the theoretical infusion rate was 6.3 cc / min, but the actually measured value was 4.2 cc / min and K = 0.7. Therefore, in the equation (1), in order to make the infusion amount Q constant, firstly, the elastic tube moving speed V ₂ is made constant. However, since the moving speed V ₂ has frictional dependency between the pressing groove 12 and the elastic tube 16 and the pressing roller 15 and includes an unstable element, the elastic tube 16 is paid out at a speed substantially equal to the moving speed V _2. It is to add a tube feeding device. Reference numeral 221 denotes a feed deceleration mechanism that decelerates the rotation of the drive motor 21 to press the pressing roller 15 at a pressing speed V ₁
The deceleration ratio of the deceleration mechanism 22 that is rotationally driven at a predetermined rotational speed is further decelerated so as to be further extended at the moving speed of the elastic tube 16. Reference numeral 222 denotes a rotation transmission mechanism for transmitting the rotation of the feed reduction mechanism 221 to the feed rollers 223, 224. The feed rollers 223, 224 are simultaneously rotated by the rotation transmission mechanism 222 at the same number of revolutions. It is sandwiched and sent in the direction of the arrow X at a speed V ₂ . At this time, the elastic tube 16 is elastically clamped (not shown) so as not to be inconvenient for infusion, and an infusion amount Q satisfying the above equation (1) is obtained, and the elastic tube 16 is slightly V _{2 at} a velocity. As it is fed out, it prevents fatigue.

The second method is to set V ₂ << V ₁ in the equation (1) to V
The influence of ₂ is prevented from appearing in the equation (1), and the rotation transmission mechanism 222 is directly driven by a pulse motor which does not require the feed reduction mechanism 221.

FIG. 2 is a diagram for explaining an embodiment of an elastic tube feed stopping device using a pulse motor.
Rotates the rotation transmission mechanism 222 shown in FIG. 1 to drive the feed rollers 223 and 224. A magnet is embedded in one of the end faces of the feed roller, and the facing position is slightly separated from the magnet. A magnetic sensor B is disposed in the
The output signal of drives the preset counter C to count. D
Drives the drive circuit F via the set / reset circuit E after the lapse of the set time set by the timer. The drive circuit F rotates the pulse motor A, and is composed of the feed rollers 223, 2
Counting rotation is performed until 24 rotations reach the preset value of the preset counter C. When the set value is reached, the set / reset circuit E is reset, the drive circuit F is stopped, the rotation of the pulse motor A is stopped, and the feeding of the elastic tube 16 is stopped. Incidentally, G is a power source.

Effect According to the tube feeding device of the elastic tube pump of the present invention described above, the elastic tube in the conventional elastic tube pump is fixed in the pressing groove, and there is a problem that the liquid cannot be infused due to fatigue due to repeated pressing in the same section. On the other hand, since the elastic tube is always automatically fed out at a constant minute speed, the reliability that an infusion cannot be performed due to fatigue is not lowered, and a highly reliable infusion pump can be obtained. Moreover, since the elastic tube is not moved intermittently, it is possible to provide an inexpensive elastic tube pump without requiring a complicated holding mechanism.

[Brief description of drawings]

FIG. 1 is a block diagram showing the construction of a feeding mechanism of an elastic tube pump according to the present invention, FIG. 2 is a block diagram showing another embodiment, and FIG. 3 is a block diagram of a conventional elastic tube pump feeding mechanism. 1 ... Elastic tube pump, 11 ... Main body, 12 ... Press groove,
13 ... Rotating shaft, 14 ... Cylindrical body, 15 ... Pressing roller, 21
... motor, 22 ... deceleration mechanism, 221 ... feed deceleration mechanism, 2
22 ... Rotation transmission mechanism, 223, 224 ... Feed rollers.

Claims (2)

[Scope of utility model registration request] 1. A pressing roller for pressing an elastic tube 16 communicating with a liquid supply source against the inner surface of the pressing groove 12 at least at two points in one section of the pressing groove 12 to seal the liquid in the elastic tube 16. In the elastic tube pump 1 that has a motor 15 that drives the pressing roller 15 to rotate in one direction, and injects liquid through the elastic tube 16, a feed speed reduction mechanism 22 that reduces the rotation of the motor 21.
1 and the feed rollers 223 and 224 that are driven by the speed reduction mechanism 221 to sandwich and feed the elastic tube 16
The elastic tube 16 is provided with a rotation transmission mechanism 222 for transmitting rotation to the elastic tube 16, and the elastic tube 16 is drawn out at a speed substantially equal to the moving speed of the elastic tube 16 while the motor 21 is rotationally driven. Tube feeder. 2. A pair of feed rollers 223, 224 in which the elastic tube 16 is rotatably sandwiched and magnets are embedded in the end faces.
And the feed roller 223 or 22 facing the magnet.
4, a magnetic sensor B for detecting the rotation of No. 4, a preset counter C for counting the rotation of the feed roller 223 or 224 detected by the magnetic sensor B, and transmitting a count completion signal when the set value is reached; Roller 223 or 22
4. A pulse motor A for feeding the elastic tube 16 at a constant speed substantially equal to the moving speed of the elastic tube 16 and stopping rotation by a count completion signal of the preset counter C. The elastic tube feeding device in the elastic tube pump according to item 1.