JP2002021743A - Tube pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact tube pump having the high operating efficiency and to be used for various purpose. SOLUTION: As a tube 3, a tube previously formed into a shape corresponding to the inner peripheral surface of a housing 1 is used. Since the tube 3 having a compact inner peripheral surface and a large curvature can be used and the pressurizing force to be applied to the tube is small, increase of the dimensions of a pump is avoided. Furthermore, since a synthetic resin tube having a high chemical resistance can be used, use is not limited like a rubber tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube pump, and more particularly to an improvement in a tube used for the pump.

[0002]

2. Description of the Related Art In a tube pump, a tube is arranged in a ring shape along a circular inner peripheral surface formed in a housing, and the tube is longitudinally moved by a pressing member such as a roller or a ring arranged inside. , And the fluid in the tube is sent out. As a tube used for this pump, a straight tube made of rubber-like elastic material and having a circular or almost circular cross section and capable of expanding and contracting in both the diametrical and longitudinal directions is generally used. It is curved and arranged along the inner peripheral surface of the housing.

When the straight tube is used in a curved state, the curved outer side is elongated and the inner side is compressed. Therefore, when the curvature exceeds the limit, the tube is bent and bent. The portion becomes flat, the effective cross-sectional area becomes small, and the desired pump capacity cannot be exhibited. In order to prevent this, it is necessary to take measures such as increasing the diameter of the inner peripheral surface of the housing to reduce the curvature as much as possible, or increasing the wall thickness of the tube to make it less likely to become flat. This is a major factor in increasing the size of the pump.

In order to operate the pump efficiently, when the tube is pressed, the tube is completely crushed so that no gap is formed inside the tube, and the tube is immediately returned to the original shape after the compression is completed. Need to be But,
In the case of a tube having a circular cross section, it is necessary to apply a pressing force such that both ends are turned back at 180 degrees in order to completely crush the tube, and in order to quickly return the shape after the compression is completed. Since it is desirable that the elastic force of the tube is large, it is necessary to apply a pressure enough to counter this large elastic force. Therefore, these factors are also a major factor in increasing the size of the pump.Additionally, extra energy that greatly exceeds the energy required for transferring the fluid is required to reduce the pump efficiency, or the tube is formed at a place where the turn is repeated. Since it is easily damaged, the maintenance cost is increased.

Further, since a tube having rubber-like elasticity which can be freely expanded and contracted is required, usable tube materials are limited. For example, polypropylene, polyethylene,
There is also a problem that a synthetic resin tube having high chemical resistance such as fluororesin cannot be used, and the application of the pump is restricted.

[0006]

The present invention focuses on such problems and provides a tube pump which can be operated with high efficiency without using a large-sized synthetic resin tube. The task was to do.

[0007]

In order to solve the above-mentioned problems, in the tube pump of the present invention, a tube preformed in a shape corresponding to the inner peripheral surface of the housing is used. With such a configuration, no extension force is applied to the outside of the curve and no compression force is applied to the inside, and a tube that is small and can cope with the inner peripheral surface having a large curvature without any problem is obtained. Can be avoided.

The pressed portion of the tube which is pressed during the operation of the pump is formed so as to have a flat cross section in which the outer side on the housing side and the inner side on the pressing member side are connected at an acute angle to each other. You. Due to such a configuration, when crushed and flattened, deformation such that both ends are turned back at 180 degrees does not occur, and the outer side and the inner side are elastic enough to return to the expanded shape. The thickness can be reduced as long as it has good properties. Therefore, compression can be performed reliably with a relatively small pressing force, and various kinds of synthetic resins as described above can be used as a material, and since there is no portion where the turn is repeated, breakage does not occur.

In the above tube, the cross-sectional shape of the outer side and the inner side of the pressed portion may be an arc shape such as an arc or a part of an ellipse close to an arc, or a polygonal line shape. In particular, in the case of an arc shape, correspondingly, one of the pressing surface of the inner peripheral surface of the housing and the pressing surface of the pressing member may have a convex arc shape and the other may have a concave arc cross-sectional shape. As a result, the pressing operation on the tube is performed smoothly. Also, the outer side and inner side of the tube are made thicker on the side in contact with the concave pressing surface, and thinner on the side in contact with the convex pressing surface. In addition, the shape can be easily restored after the end of the compression.

The tube may be covered with a rubber tube on the outside. In this case, since the elastic force of the rubber tube is applied, the shape is restored more quickly after the compression is completed.

This type of pump is not used alone, but it is necessary to connect a tube to an external device to transfer the fluid to be transferred to and from the device. Therefore, it is desirable to form connection ports integrally at both ends of the tube, thereby facilitating connection with an external device.

[0012]

Next, an embodiment of the present invention will be described. FIG. 1 is a schematic front view of the entire pump, and FIG. 2 is a perspective view of an example of a tube and a cross-sectional view of a main part. Since the general structure of the tube pump is well known, the description of FIG. 1 will be simplified.

In FIG. 1, reference numeral 1 denotes a housing on which an inner peripheral surface 2 is formed. The inner peripheral surface 2 has a pressurizing surface 2a formed in a circular shape in a range larger than a semicircle and smaller than the entire circumference. A portion where 2a is not formed is an opening 2b. Reference numeral 3 denotes a tube, which is disposed along the inner peripheral surface 2 and has linear drawers 3a at both ends formed in openings 2b.
From the housing 1.

Reference numeral 4 denotes a ring-shaped pressing member disposed inside the tube 3, which has a double structure of an inner ring 41 and an outer ring 42. The inner ring 41 is made of a rigid material having a small coefficient of friction, for example, a synthetic resin molded article of a fluororesin. The outer ring 42 is made of an elastic material having a large coefficient of friction such as rubber. The outer periphery is a pressing surface 4b.

Reference numeral 5 denotes an eccentric drive unit disposed inside the pressing member 4, and reference numeral 6 denotes a rotary shaft to which the eccentric drive unit 5 is attached. The eccentric drive unit 5 rotates the pressing member 4 along the inner peripheral surface 2 of the housing 1 by rotating, for example, clockwise while sliding the circular outer peripheral surface 5 a against the inner peripheral surface 4 a of the pressing member 4. The tube 3 is moved between the pressurizing surfaces 2a and 4b so as to sequentially press the tube 3 toward the drawer 3a on the left side of the drawing. A drive motor (not shown) is disposed on the rear surface of the housing 1, and its output shaft serves as the rotating shaft 6 as it is, or is connected to the rotating shaft 6 via an appropriate speed reducer.

The tube 3 is a molded product of a synthetic resin having high chemical resistance such as polypropylene, polyethylene, and fluororesin. The whole has a shape as shown in FIG. 2 (a), and a linear drawer 3a corresponding to the opening 2b is integrated with both ends of a ring-shaped pressed portion 3c corresponding to the pressing surface 2a of the housing 1. It is formed in. Further, a connection port 3b for connecting to a tube of another device is integrally formed at an end of each drawer section 3a, and the connection port 3b is provided with appropriate unevenness for retaining. Since the tube 3 is a molded product of the above-described material, it does not have the flexibility of rubber, and has a certain degree of hardness and rigidity. It can be deformed but returns to its original shape when deformed. It has become. It should be noted that the illustrated shape is an example, and it is a matter of course that the tube is formed into a shape that matches the inner peripheral surface of the housing in which the tube is used.

FIG. 2B shows a cross section of the pressed portion 3c taken along a plane perpendicular to the longitudinal direction. That is, the cross-sectional shape is a flat shape in which the outer side 3d on the side in contact with the housing 1 and the inner side 3e on the side in contact with the pressing member 4 are continuous at the connecting portion 3f, and the angle at which the outer side 3d and the inner side 3e intersect A has an acute angle, and the outer side 3d and the inner side 3e are both arcs bulging slightly outward. Since the pressed portion 3c is extended in a flat direction, the thickness of the outer side 3d and the inner side 3e is considerably thinner than that of the drawer 3a.

Since the tube 3 having the above-described shape is used in the tube pump 11 of this embodiment, the outer side 3d and the inner side 3e having a slightly expanded shape and a small thickness may be flattened during compression. Since the connecting portion 3f has an acute angle, the amount of deformation when compressed is small. For this reason, the circular rubber tube can be completely crushed with a small pressing force as compared with the case of pressing the circular rubber tube, and the connecting portion 3f is less likely to be damaged due to repeated deformation. In addition, since the deformation of the outer side 3d and the inner side 3e is small, the elasticity of the outer side 3d, the inner side 3e, and the connecting portion 3f to return to the original shape respectively, and the return to the original shape after the end of the compression is compared. It is done promptly.

FIG. 3 shows an example in which the cross section of the pressed portion 3c has another shape. (a) is a figure in which the outer side 3d and the inner side 3e are bulged outward and bent, and besides such a rhombus, a flat hexagon or the like is also possible. FIG. 2 (b) shows a shape similar to FIG. 2 (b) in which the connecting portion 3f has a fin shape extending in a flat direction, and the outer side 3d and the inner side 3e have a fin-like connecting portion. Since the shape swells smoothly from the direction parallel to 3f, the connecting portion 3f
, And it is easy to squeeze into a flat shape. In this case, if the sum of the thicknesses of the outer side 3d and the inner side 3e is set to be equal to the thickness of the connecting portion 3f, the thickness when pressed flat is constant as a whole.

The above example is based on the premise that the pressing surface 2a of the housing 1 and the pressing surface 4b of the pressing member 4 are cylindrical and have a straight cross section.
c is a section symmetrical with respect to the center line in the flat direction.

On the other hand, as shown in FIG. 4, one cross section of the pressing surface 2a on the housing 1 side and the pressing surface 4b of the pressing member 4 has a convex arc shape, and the other cross section corresponds to this. May be formed into a concave arc shape. In this case, the outer side 3d and the inner side 3e of the tube 3 are desirably thicker on the side in contact with the concave pressing surface and thinner on the side in contact with the convex pressing surface. In FIG. 4, the pressing surface 4b is convex and the pressing surface 2a is concave, and the tube 3 has a thicker outer side 3d and a thinner inner side 3e.
With this shape, the side that is thin and easily deformed when pressed,
That is, in the illustrated example, it is easy to deform the inner side 3e and press it against the outer side 3d with no gap as indicated by a chain line, so that a large pressing force is not required for pressing. After the end of the compression, the shape returns to the original shape due to the elasticity of the inner side 3e which is going to return to the original shape.

By the way, a thin-walled object having a slightly expanded shape has the property of suddenly denting due to a kind of buckling phenomenon when the external pressure exceeds the dent pressure, and suddenly returning to the original shape when the external pressure disappears. In the case of the tube 3 as well, by appropriately selecting the thickness and the bulging shape of the inner side 3e, the inner side 3e is easily dented with a slight pressurization, and returns to the original state as soon as the pressing force is removed. Therefore, by utilizing this property, it is possible to obtain a tube in which the inner side 3e and the outer side 3d are completely in close contact with each other by compression with a small pressing force, and quickly return to the original shape after the compression is completed. Note that such a so-called Pecan effect can be obtained by appropriately selecting the thickness and the bulging shape, so that the same effect can be obtained even when the outer side 3d and the inner side 3e have the same thickness.

FIG. 5 shows an example in which the shape restoring force is improved by a structure different from the above-described countermeasure. At least the pressed portion 3c of the tube 3 which is a synthetic resin molded product is covered with the rubber tube 8. is there. The rubber tube 8 is desirably of such a size that when it is put on the tube 3, it becomes slightly stretched. With this configuration, in the state where the rubber tube 8 is compressed and flattened as shown in FIG. 3 (b), a stress is generated in the stretched rubber tube 8 so as to contract inward as indicated by an arrow. The stress of the rubber tube 8 is superimposed on the self-restoring force, and can quickly return to the original shape after the end of the compression.

Note that, instead of the structure in which the rubber tube 8 is covered on the tube 3 as shown in FIG. 5, for example, a cushion material such as a sponge is arranged at a position where the connecting portions 3f at both ends come into contact when pressed and flattened. May be. That is,
The force for pushing back the connecting portion 3f is generated by the cushion material. With such a configuration, the shape can be quickly restored after the end of the compression.

[0025]

As is apparent from the above description, the tube pump of the present invention uses a tube preformed in a shape corresponding to the inner peripheral surface of the housing. Therefore, no extension force is applied to the outside of the curve and no compression force is applied to the inside, and a tube that is small and can be used without difficulty even on the inner peripheral surface having a large curvature can be obtained. Can be

Further, the pressed portion of the tube which is pressed during the operation of the pump is formed such that the outer side on the housing side and the inner side on the pressurizing member side have a flat cross section in which an acute angle continues. In this case, since the thickness of the pressed portion can be reduced and the amount of deformation at the time of compression can be reduced, the compression can be reliably performed with a relatively small pressing force. In this regard, the pump can be prevented from being enlarged. In addition, the tube is not damaged due to repeated deformation, and various synthetic resins can be used as the material of the tube. Therefore, a tube pump that can be used for various chemicals and chemical products can be obtained.

The outer and inner sides of the pressed portion of the tube are arc-shaped in cross section. Correspondingly, one of the cross section of the pressurizing surface of the inner peripheral surface of the housing and the pressurizing surface of the pressurizing member is convex, and the other is convex. If the tube has a concave arc shape and the outer and inner walls of the tube are thicker on the side in contact with the concave pressing surface and thinner on the side in contact with the convex pressing surface, the pressing force can be reduced and the compression It is easy to quickly return the tube to its original shape after completion.

In the case where the outside of the tube is covered with the rubber tube, the elastic force is applied by the rubber tube, so that the shape is quickly restored after the end of the compression.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a tube pump according to an embodiment of the present invention.

FIG. 2 is a perspective view of the tube and a cross-sectional view of a pressed portion.

FIG. 3 is a cross-sectional view showing another shape of the pressed portion of the tube.

FIG. 4 is a cross-sectional view illustrating another shape of the pressing surface and the pressed portion according to the first embodiment.

FIG. 5 is a cross-sectional view showing another configuration of the above tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inner peripheral surface 2a Pressurizing surface 3 Tube 3b Connection port 3c Pressed part 3d Outer side 3e Inner side 4 Pressing member 4b Pressing surface 5 Eccentric driver 6 Rotating shaft 11 Tube pump

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 593169005 Nagao Tamagawa 1-10-22 Sakuragaoka, Minoh-shi, Osaka (72) Inventor Yutaka Doi 323-15, Uchiage, Neyagawa-shi, Osaka Prefecture 2-307 Minami 2-307 (72) Inventor Fumio Nakamura 1-230-30 Konoike-cho, Higashi-Osaka-shi, Osaka (72) Inventor Katsuhiko Morita 65-48, Futari Yawata, Yawata-shi, Kyoto 65-48 (72) Nagao Tamagawa 1-10-22, Sakuragaoka, Minoh-shi, Osaka

Claims (8)

[Claims] 1. A tube is arranged in a ring shape along a circular inner peripheral surface formed in a housing, and the tube is sequentially pressed in a longitudinal direction by a pressurizing member arranged inside, so that a fluid in the tube is compressed. A tube pump, wherein the tube is formed in advance in a shape corresponding to the inner peripheral surface of the housing. 2. The tube is made of a synthetic resin, and the section to be pressed has a flat shape in which an outer side on the housing side and an inner side on the pressing member side are connected at an acute angle to each other. The tube pump according to claim 1. 3. The tube pump according to claim 2, wherein the cross section of the outer side and the inner side of the tube is arc-shaped. 4. The tube pump according to claim 2, wherein the cross section of the outer side and the inner side of the tube is a polygonal line. 5. The tube pump according to claim 3, wherein a cross section of the pressurizing surface of the inner peripheral surface of the housing and the pressurizing surface of the pressurizing member are arcuate in shape, one of which is convex and the other is concave. 6. The tube pump according to claim 5, wherein the outer side and the inner side of the tube are thicker on the side contacting the concave pressing surface and thinner on the side contacting the convex pressing surface. 7. The tube pump according to claim 1, wherein the outside of the tube is covered with a rubber tube. 8. The tube pump according to claim 1, wherein connection ports are integrally formed at both ends of the tube.