JPH0544656A - Tubing pump - Google Patents

Abstract

PURPOSE:To provide a tubing pump in which the pulsation of the discharged fluid is suppressed and the controllability for the fluid discharge quantity is improved. CONSTITUTION:An elastic tube 6 is installed between a tube pressing roller 3 on a rotor member 2 and the tube guide 40 of a tube pressing member 4 which is set close to the circular motion orbit of the pressing roller 3, accompanied with the revolution of the rotor member 2, and fluid transfer is carried out by squeezing the tube 6 by the circular motion of the pressing roller 3. A plurality of pressing rollers 3 are arranged so as to perform a circular motion, inscribed with a common supposed circle, and the guide surface 40 is formed so that the gap between the face and the supposed circle forms a constant gap for closing the tube 6 between the pressing roller 3 and the guide surface 40 in the previously determined fluid closing feeding region X. In a fluid releasing region Y which is continuous to the closing feeding region, the gap is formed in the gradually spread form so that the accumulative fluid discharge quantity is nearly proportional to the revolution angle of the rotor member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump, and more particularly to a tube pressing member supported by a rotor member which is rotationally driven, and a tube guide for a tube pressing member which faces a circular motion trajectory of the pressing member due to the rotation of the rotor member. The present invention relates to a tubing pump in which an elastic tube is attached between a surface and a surface, and the elastic tube is squeezed by the circular motion of the pressing member to convey a fluid.

[0002]

2. Description of the Related Art A tubing pump is known as a peristaltic pump or the like, and since a fluid to be transported is transported while being confined in a tube, contamination of the fluid to be transported is small,
It is used in fields where contamination of the transported fluid is disliked.

[0003]

However, due to the structure of the tubing pump, the discharge fluid pulsates.
That is, in the tubing pump, since the fluid is conveyed by squeezing the tube with the rotation of the rotor member by the tube pressing member that makes a circular motion around the rotation center of the rotor member, when the pressing member compresses or releases the tube, The volume of the tube changes at the portion in contact with the pressing member.
For example, on the side of releasing the tube, the compression is released, and while the pressing member is rotating, this cycle is repeated, and this cycle causes an increase or decrease in the discharge amount, resulting in pulsation or pulsation.

As described above, since fluid contamination is suppressed, the tubing pump is used to dispense a liquid medium to a large number of culture media such as flasks, petri dishes, microplates, etc. for culturing biological cells and various tests. It is possible to use it for dispensing work such as dispensing test liquid to a large number of test tubes, etc., but since pulsation occurs in the discharged fluid, it is difficult to control the fluid discharge amount accurately, so It is difficult to use for such dispensing work that requires accurate quantity.

Therefore, an object of the present invention is to provide a tubing pump in which the pulsation of discharge fluid is suppressed and the controllability of the discharge amount of fluid is good.

[0006]

In order to solve the above-mentioned problems, the inventor of the present invention has conducted extensive research and the more the tube is rapidly released on the release side of the tube, the larger the pulsation becomes, and the more gradually the tube is released. I found that the pulsation became smaller,
The present invention has been completed. That is, the present invention provides an elastic tube between a plurality of tube pressing members supported by a rotationally driven rotor member and a tube guide surface of a tube pressing member facing a circular motion trajectory of the pressing members due to rotation of the rotor member. In a tubing pump that carries fluid by squeezing the elastic tube by circular movement of the pressing member, the plurality of tube pressing members are arranged so as to make a circular motion by inscribed in a common virtual circle, The tube guide surface is formed such that the gap between the surface and the circle is a predetermined gap that can close the tube between the pressing member and the guide surface in a predetermined fluid confinement feed area, and the confinement feed area is formed. In the fluid release area continuous with the tub, the tub is formed so that the cumulative fluid discharge amount is gradually expanded so as to be substantially proportional to the rotation angle of the rotor member. It is intended to provide a Guponpu.

[0007]

According to the pump of the present invention, of the tubes mounted between the tube pressing member on the rotor member and the tube guide surface of the tube pressing member, the portion in the fluid confinement feed region is localized by the tube pressing member. Is compressed and closed, and the locally closed position moves to the fluid release side due to the circular movement of the pressing member, so that the fluid trapped between the adjacent closed positions by the adjacent pressing members becomes the fluid release side. Be transported to.

With respect to the fluid sent to the fluid release area, the pressing member further continues the circular movement from the opening of the opening area to the outlet thereof, and the gap between the pressing member and the tube guide surface gradually expands. It is gradually released from the compressed state without rapidly increasing the internal volume of the tube, whereby the fluid is discharged with the pulsation suppressed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show one embodiment, FIG. 1 is a front view showing a cutaway part of the cover, and FIG. 2 is FIG.
3 is a side view seen from the left in FIG. 3, FIG. 3 is a plan view of a part of the embodiment of FIG. 1, FIG. 4 is a perspective view of a part of the tube holding member elevating mechanism, and FIG. FIG. 6 is a diagram illustrating the lock mechanism in the position, and FIG. 6 is a plan view of the tube holding device.

This tubing pump PM has a disk-shaped rotor member 2 rotatably supported by a pump frame 10, and four pressing members rotatably supported by a peripheral portion of the rotor member 2 at a central angle of 90 °. It includes a roller 3, a tube pressing member 4 arranged outside the pressing roller, and a tube 6 mounted between the tube guide surface 40 of the member 4 and the pressing roller 3.

The rotor member 2 is provided on a vertical flat surface 101 of the frame 10 and is fitted into a circular recess 102. The rotor member 2 is rotatably supported by a shaft 21 perpendicular to the bottom surface of the recess, and a stepping motor 22 whose rotation angle can be controlled. Is driven to rotate. Four
The individual pressing rollers 3 have the same outer diameter, and their rotation centers B are equidistant from the rotation center A of the rotor member 2.

The tube 6 is an elastically deformable silicone tube. The tube guide surface 40 of the tube pressing member 4 faces the circular movement trajectory of the tube pressing member 3 from above over 180 ° as a central angle around the rotation center A of the rotor member 2. A tube support surface 401a is continuously provided at a fluid conveyance start end 401 of the guide surface 40 in a contact surface direction with respect to this portion, and a fluid discharge side end 402 of the surface 40 has a tube support surface with respect to this portion. 402a are arranged in series.

In the pressing member 4, these guide surfaces 4
0 and the lower end of the space partitioned by the tube support surfaces 401a and 402a are open. Back surface 41 of the pressing member 4
(See FIG. 2) is formed flat and is in contact with the rotor member mounting surface 101 of the frame 10. However, as shown in FIG. 3, the back surface 41 of the pressing member 4 is provided with a pair of protrusions 411 and 411, and each protrusion is provided in the wall 110 in contact with the member 4 of the frame 10 in the vertical direction. Long hole 1
It is fitted in 11 so that it can slide up and down. A block 412 is screwed to a portion of each protruding portion 411 protruding rearward from the wall 110, and the block 412 is slidably contactable with the rear surface 112 of the wall 110. As a result, the member 4 is guided up and down. The member 4 has a regular fluid transfer position P1 in which the lower end of the member 4 abuts on the tube holding device 9 below the frame,
It is possible to move up and down from this position and move up and down between the retracted positions P2 where the tube 6 can be attached and detached. Details of this lifting mechanism will be clarified later in the description.

As shown in FIG. 3, a pair of notched recesses 42, 42 are formed at the upper end of the pressing member 4, and a supporting member 103 protruding from the frame flat surface 101 is formed in each recess.
The cover support member 43 rotatably connected by the pin 104 is inserted therein. Each cover support member 43
Is a bottom surface 421 of the pressing member recess 42 when the pressing member 4 is in the regular position P1.
To fix the member 4 to the position P1.

A cover 44 made of a transparent material or a material close to transparent is attached to the cover supporting members 43, 43 with a screw 45. The cover is in contact with the front surface of the pressing member 4 when the pressing member 4 is at the regular position P1, and the front surface of the pump is fixed. cover. As shown in FIG. 4, each cover support member 43 has a slit 432 formed upward from the lower surface 431, and a link 46 is loosely fitted therein. The link 46 has a long hole 461, and is hung from the member 43 via a pin 47 that passes through the long hole.

The lower end of the link 46 is loosely fitted in a slit 422 formed further downward from the bottom surface 421 of the recess 42 of the pressing member 4, and the pin 48 provided on the member 4 is inserted in the link elongated hole 461 there. It is fitted loosely. Therefore, when the pressing member 4 is in the regular position P1 and the cover 44 is closed, the pressing member 4 is held between the lower surface 431 of each cover supporting member 43 and the tube holding device 9 below the frame. Fixed. Further, when the cover 44 is rotated forward and upward from this state, the cover support member 43 is also rotated upward as shown in FIG. By engaging the pin 48 of the pressing member 4 and pulling it up, the pressing member 4 can be attached to and detached from the tube by the rising / retracting position P.
Can be lifted up to 2.

When the cover is closed, the member 4 is pushed by the cover supporting member 431 and fixed at the regular position P1. 1 and 2, reference numeral 49 is a finger insertion recess provided in the member 4 for opening the cover 44. This pump is
Further, when the tube pressing member 4 is arranged at the regular position P1 or the retracted position P2, a mechanism 400 for locking the member at that position is provided.

This locking mechanism 400, as shown in FIGS. 3 and 5, has a rear projection 411 of the tube pressing member 4.
It includes a ball plunger 401 mounted on a block 412 screwed to and two upper and lower lateral grooves 402, 403 (see FIG. 5) on the back surface 112 of the frame wall 110. Ball plunger 401 includes a ball that is constantly urged by a spring toward wall 110. The upper groove 402 is a pressing member 4.
The groove 403 on the lower side is provided corresponding to the normal position P1 of the member 4. When the tube pressing member 4 is arranged at the regular position P1, the ball of the ball plunger 401 fits into the lower groove 403 and locks the member 4 at that position. When the member 4 is arranged in the ascending / retracting position P2, the ball of the plunger 401 fits in the upper groove 402, and the member 4 is locked in that position. During the movement between the positions P1 and P2, the ball of the plunger is retracted by the wall rear surface 112 against the spring force.

The tube holding device 9 at the lower end of the frame is
The tube 6 extending downward along the tube supporting surfaces 401a and 402a (see FIG. 1) of the pressing member 4 is held at a predetermined position. This tube holding device 9 is shown in FIG.
As shown in detail in FIG.
It includes a fixed block 91 for receiving a tube, which is attached via a stopper, a pair of stoppers (tube holding portions) 92 hinged to the block, and a one-touch lock / unlock mechanism 93 for the stopper.

The block 91 is provided with a pair of vertical grooves 911 having a semicircular cross section into which the tubes 6 extending downward from the tube supporting surfaces 401a and 402a of the pressing member 4 are fitted. The stopper 92 is provided corresponding to each groove 911, and has a groove 921 having a semicircular cross section that can face the groove 911. The tube 6 is held in place by closing the stopper 92 so that it fits into the grooves 911 and 921.

Each stopper 92 has a protruding pin 92 on its inner surface.
2, the pin penetrates a pin hole 912 provided in the block 91 when the stopper 92 is closed,
No. 6 hole 961 is reached. A notch 922a with which the end of the spring 931 of the mechanism 93, which will be described in detail later, engages is provided at the tip of each pin 922. Between the blocks 96 and 91, a leaf spring 931 whose central portion is formed in a mountain shape is arranged.
A central hole 962 of the block 96 is provided in the center of the mountain height of the spring 931.
The other part is sandwiched between the blocks 96 and 91 so as to allow a slight lateral movement. The leaf spring 931 is
Each of the left and right ends has a long hole (not shown) extending in the left-right direction, and this long hole is engaged with the rear end of the spring plunger 94 extending from the block 91 to the front surface. When the pin 922 is inserted into the hole 961 of the block 96 by closing the stopper 92, the end of the spring 931 automatically engages with the notch 922a at the tip of the pin to prevent the pin 922 from coming off. Thus, the stopper 92 is one-touch locked in the closed position. Each spring plunger 9
4 always applies a force in the opening direction to the stopper placed in the closed position.

A push button 95 for operating a spring penetrates through the center of the block 91 from the front side. When the button 95 is pushed from the front side of the block to press the center of the spring, the left and right ends of the spring 931 are pushed. It is displaced toward the center. Due to this displacement, both ends of the spring are pin 9 of the stopper 92.
The stopper 92 can be opened by being disengaged from the notch 922a of the 22.

When the spring 931 disengages from the pin 922, the stopper 92 is pushed by the plunger 94 and automatically opens, thus allowing the tube to be attached and detached. Next, the tube guide surface 40 of the pressing member 4 will be described. Of the gap between the guide surface 40 and the pressing roller 3, the guide surface 4
From the fluid transfer start end 401 of 0 to the position Q rotated 90 ° around the rotor member rotation center A, the fluid confinement feed area X
And the guide surface 40 rotated 90 ° further from the position Q.
To the end 402 is the fluid release area Y.

In the feed area X, the gap distance Ds between the guide surface 40 and the common imaginary circle C on which the roller 3 on the rotor member is inscribed is constant, which is the roller 3 and the guide surface 40.
It is set so that the tube 6 can be compressed and closed between and. However, in the release area Y, the gap distance between the virtual circle C and the guide surface 40 gradually increases so that the cumulative fluid discharge amount is substantially proportional to the rotation angle of the rotor member 2.

More specifically, this gap is defined by the release area Y.
The guide surface 40 is determined as follows. First, a tube pressing member for obtaining basic data was manufactured. At this time, the tube guide surface was determined as follows. That is, as shown in FIG. 7, the virtual circle C
Consider a circle Cs having a radius (r + Ds) obtained by adding a constant gap distance Ds in the feed range X to the radius r of. Next, a point E on the circle Cs at the boundary between the feed area X and the release area Y is set as a starting point, and a position on the circle Cs advanced by 90 ° to the release area Y side is defined as G1.

On the radius extension of the circle Cs connecting the center A of the circle Cs (corresponding to the rotation center A of the rotor member 2) and the point G1, a position G separated from the point G1 by a distance L is obtained. This L is equal to the inner diameter of the tube 6. That is, the tube is set to be completely released between G and G1. Then point E
Let D be the point where the perpendicular bisector of the line segment connecting the point G and the point G intersects the point E of the circle Cs and the diameter line passing through the center A. An arc F circumscribing the circle Cs at the point E centering on the point D and starting from the point E to reaching the point G is drawn.

Next, the center angle α of the arc F with the point A as the center is set.
(For example, 5 °) is equally divided. When moving from the point E to the end point G of the arc F, in other words, to the position corresponding to the end 402 of the guide surface 40 by the angle α, the discharge amount caused by the gradual increase of the gap between the circle Cs and the arc F. The cumulative value of is sequentially measured. As shown in FIG. 8, the horizontal axis represents the angle and the vertical axis represents the cumulative ejection amount, and a cumulative ejection amount curve L1 is drawn.

On the other hand, the vertical axis of the graph of FIG. 8 is the gap distance between the circle Cs and the arc F, and the gap distance at each position when advancing from the point E by the angle α is calculated and obtained. Shown as curve L2 above. Furthermore, the starting point and the ending point H of the line L1 are connected by a straight line L3. This straight line L3 is the rotor member 2
It means an ideal cumulative discharge amount without pulsation that increases in proportion to the rotation angle of.

Further, the predetermined angle β on the graph
Every time (for example, 10 °), the ideal discharge amount a at that angle is obtained from the line L3, and the line L1 corresponding to this value a is obtained.
The upper point b is obtained, the point c on the line L2 corresponding to this point b is obtained, and the gap distance (the gap distance at the point d in the figure) corresponding to this point c is calculated as the gap distance Dx at that angular position. To decide.

Thus, the angle β from the point E on the circle Cs
The gap distance Dx between the circle Cs and the circular arc F is determined one after another. In FIG. 8, the line L4 is a line connecting the obtained Dx. Thus, from the curve L4 of FIG. 8, the relationship between the arbitrary rotation angle of the pressing roller 3 accompanying the rotation of the rotor member 2 and the ideal gap Dx at that time can be obtained.

Next, as shown in FIG. 9, the center B of the roller 3
Center angles 0 to 9 on the moving arc line C _B (see FIG. 1)
A circle having a radius rx is drawn at a position advanced by an arbitrary angle θx from the position of the central angle 0 ° over the range of 0 °. This radius rx
Is the line L at the position advanced by the angle θx on the horizontal axis in FIG.
The ideal gap Dx obtained from 4 and the above-mentioned constant gap Ds,
It is the sum of the radius r1 of the roller 3 (Dx + Ds + r1).
Thus, the radius rx over the range 0-90 °
A large number of circles are obtained, and the guide surface is determined by using the circumscribed envelope of these circles as an ideal guide curve for determining the guide surface to be obtained. In FIG. 9, the start point e of the envelope at the central angle of 0 ° corresponds to the boundary position between the feed area X and the release area Y, and the end point g corresponds to the end point 402 (see FIG. 1) of the release area Y.

It should be noted that the ideal guide curve formed of the envelope may be approximately obtained and used as the curve for determining the guide surface. As an example of the method for obtaining the approximation, as shown in FIG. 10, every time the arc line C _B advances by an arbitrary angle γ, a circle Cx having a radius rx at that position is drawn, and
By approximating this, circles with the same radius rx are drawn on both sides (for example, 5 degrees on both sides at the central angle), arcs Lx circumscribing these three circles Cx are sequentially obtained, and these arcs are connected. In this embodiment, the guide surface is determined by this approximate method.

As shown in FIG. 2, the pump frame 10 has two pairs of upper and lower rollers 105 on its rear surface (only one pair is shown in the figure, and the other pair is hidden behind it). This roller 105 can be moved along the rail by fitting the roller 105 from above and below onto the rail 107 on the pump installation table 106 installed in the dispensing work space, for example.

According to the pump PM described above, the pressing member 4 can be easily mounted between the pressing member 3 and the pressing roller 3 at the retracted position P2 without fear of damage.
Next, the member 4 is placed in the regular position P1, and the tube 6 is fixed in place by the tube holding device 9 without fear of damage.
If the tube 6 is easily held, and one end of the tube 6 is connected to, for example, a culture solution bottle (not shown) and the other end is connected to a dispensing head and the rotor member 2 is driven and rotated by the motor 22, the discharged fluid It is possible to perform the dispensing work by accurately controlling the discharge amount in a state where the pulsating flow or pulsation is suppressed to the extent that it does not pose a practical problem.

The number of pressing rollers 3 is not limited to the number in the above embodiment as long as it has a fluid transport function. However, in order to selectively dispose the pressing members 4 at the positions P1 and P2 as described above, at least four pressing members 4 are required so as to obtain a fluid transfer function and to move the pressing members 4 in such a manner.

[0036]

As described above, according to the present invention, it is possible to provide a tubing pump in which the pulsation of the discharge fluid is suppressed and the controllability of the fluid discharge amount is good.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of the present invention with a cover partially cut away.

FIG. 2 is a side view of the embodiment shown in FIG.

3 is a plan view of a portion of the embodiment shown in FIG.

FIG. 4 is a perspective view of a part of a lifting mechanism for a tube pressing member.

FIG. 5 is an explanatory view of a lock mechanism of a tube pressing member.

FIG. 6 is a plan view of the tube holding device.

FIG. 7 is a diagram illustrating how to obtain a tube guide surface of a tube pressing member for obtaining basic data.

FIG. 8 is a diagram illustrating how to determine a gap distance between a tube guide surface and a pressing roller.

FIG. 9 is a diagram illustrating how to find an ideal tube guide surface line.

FIG. 10 is a diagram illustrating an example of how to obtain an approximate tube guide surface line.

[Explanation of symbols]

 10 Pump Frame 2 Rotor Member 22 Motor 3 Pressing Roller 4 Tube Holding Member P1 Regular Position P2 Retracted Position 40 Tube Guide Surface 42 Recess 4 on Member 4 43 Cover Support Member 44 Cover 400 Tube Holding Member Locking Mechanism 101 Frame 10 Flatness Surface 103 Projection Supporting Member from Frame 104 Pin 6 Tube 9 Tube Holding Device 91 Fixed Block 92 Stopper 93 One-touch Lock / Unlock Mechanism

Claims (1)

[Claims] 1. An elastic tube between a plurality of tube pressing members supported by a rotationally driven rotor member and a tube guide surface of a tube pressing member facing a circular motion trajectory of the pressing members due to rotation of the rotor member. In a tubing pump that carries fluid by squeezing the elastic tube by circular movement of the pressing member, the plurality of tube pressing members are arranged so as to make a circular motion by inscribed in a common virtual circle, The tube guide surface is formed such that the gap between the surface and the circle is a predetermined gap that can close the tube between the pressing member and the guide surface in a predetermined fluid confinement feed area, and the confinement feed area is formed. In the fluid release region continuous with, the tubing point is formed so that the cumulative fluid discharge amount is gradually expanded so as to be substantially proportional to the rotation angle of the rotor member. Pump.