JP4122029B2 - Tube pump - Google Patents

Description

  The present invention relates to a tube pump that performs a pumping action by compressing a tube arranged in a ring shape along an inner peripheral surface of a cylindrical chamber in one direction by a ring-shaped pressurizing member that is arranged on the inner side and moves eccentrically. .

This type of tube pump applies a tensile force to the tube as the pressurizing member moves, reducing this pulling force and eliminating the damage to the tube due to friction with the cylindrical chamber or pressurizing member. It is common practice to apply a lubricant such as to the tube and its periphery. In order to maintain the effect of this lubricant over a long period of time, it has been proposed to provide a grease reservoir in the pressure member and supply the lubricant from the grease reservoir to the outer peripheral surface of the pressure member.
Japanese Patent Laid-Open No. 11-13648

  This type of tube pump has a type in which the tube is directly pressurized with a pressure member formed of a hard material such as metal, and an outer ring made of an elastic material such as rubber is provided on the outer periphery of the pressure member. There is a type in which the tube is pressurized with a ring, but in any case, a certain amount of gap exists between the pressure member and the side wall of the cylindrical chamber. Since the tube is suddenly compressed as the pump speed increases, the lubricant is applied from the gap between the pressurizing member and the side wall of the cylindrical chamber to the center of the cylindrical chamber, that is, pressurizing by the large pressure applied instantaneously. It becomes easy to be pushed out to the part provided with the eccentric cam etc. which rotationally drive a member. The force that returns to the tube does not act on the extruded lubricant, so it stays there, and even if a grease reservoir is provided, the capacity is limited, so lubrication is required as the operation continues The tube surface is almost free of lubricant, making it difficult to stably exert a lubricating action for a long period of time. This phenomenon is particularly remarkable in a pump having a high rotational speed.

  The present invention pays attention to these points, and prevents the lubricant from being pushed out toward the central portion of the pressurizing member so that the lubricating action can be stably performed over a long period of time even in a pump having a high rotational speed. Is made as an issue.

In order to achieve the above object, in the tube pump of the present invention, an ear piece protruding in the axial direction of the pressurizing member is formed in a ring shape on the outer peripheral side edge of the pressurizing member made of an elastic material. are the seal to so that with respect to the central portion of the by sliding contact with the side wall of the cylindrical chamber cylinder chamber tube. In this application, the term “sliding contact” is used as a term indicating a state of sliding while contacting.

  The ear piece may be composed of a first ear piece formed on the outer peripheral side and a second ear piece formed on the inner peripheral side of the first ear piece. A reservoir groove for lubricant is formed between the one ear piece and the second ear piece.

  When the ear pieces are formed in a double manner as described above, it is desirable that the first ear piece bend easily and the second ear piece be difficult to bend. In this case, a plurality of notches may be provided in the first ear piece.

  Since the ear piece of the pressure member is in sliding contact with the side wall of the cylindrical chamber and the tube is sealed, the lubricant passes through the sliding contact portion between the ear piece and the side wall and moves toward the center of the pressure member. It becomes difficult to be pushed out, and when the tube is pressed, the lubricant escapes in the longitudinal direction of the tube. For this reason, even when it is suddenly pressed, the amount of lubricant that passes through the sliding contact portion between the ear piece and the side wall is reduced, so that the lubricant stays on the tube surface and its periphery, and the lubricating action can be maintained for a long time. It becomes possible.

  In the case where the above-mentioned ear piece has a double structure of the first ear piece and the second ear piece, the lubricant that has passed through the sliding contact portion between the first ear piece and the side wall of the cylindrical chamber accumulates freely in the accumulation groove. The pressure at the time of compression is reduced. For this reason, the lubricant does not pass through the sliding contact portion between the second ear piece and the side wall of the cylindrical chamber, but stays in the accumulation groove and is not pushed out toward the center portion of the pressure member.

  Also, in the case where the first ear piece is easy to bend and the second ear piece is hard to be bent, the first ear piece accumulates during compression and the lubricant is easily deflected in the groove direction, and the lubricant is easily pushed out to the accumulation groove. When the pressure disappears, the lubricant is bent in the outer peripheral direction and the lubricant easily returns in the tube direction. Furthermore, when a plurality of cutouts are provided in the first ear piece, the lubricant easily returns to the tube direction through the cutouts in the uncompressed locations, so that the pressure during compression is further reduced, Pushing of the lubricant in the direction of the center of the pressure member is prevented.

  Examples of the present invention will be described below.

  FIG. 1 shows a first embodiment, and is a sectional view showing a state in which the left side of the tube is compressed and the right side is not compressed. The entire tube pump has a structure as disclosed in, for example, the above-mentioned patent document, but a diagram showing the entire structure is omitted because it is not directly related to the invention of this application.

  In the figure, 1 is a pump housing composed of a body case 1a having a cylindrical chamber 2 and a lid 1b, 3 is a tube arranged in a ring shape along the inner peripheral surface 2a of the cylindrical chamber 2, Both ends are drawn out from a lead-out portion (not shown) formed in the pump housing 1. In addition, although the tube 3 is comprised with rubber | gum, synthetic resin, etc., the cross-sectional display by a diagonal line etc. is abbreviate | omitted in the figure. Reference numeral 4 denotes a ring-shaped pressurizing member disposed inside the tube 3, and an outer ring 4b made of an elastic material such as rubber is fitted to the outer side of the inner ring 4a. As this elastic material, for example, NBR having a hardness of around 70 ° is used. Reference numeral 5 denotes an eccentric rotor disposed inside the pressure member 4, and 6 denotes a rotating shaft. The eccentric rotor 5 is fixed to the rotating shaft 6, and the outer peripheral portion 5 a rotates while being in sliding contact with the inner peripheral surface 4 c of the inner ring 4 a of the pressurizing member 4, so that the pressurizing member 4 is moved along the inner peripheral surface 2 a. It is configured to make an eccentric motion. Reference numeral 7 denotes a motor with a speed reducer for driving the rotary shaft 6 and is provided on the outer surface of the main body case 1a.

  Reference numeral 11 denotes an ear piece protruding from both side edges of the outer peripheral surface 4c of the outer ring 4b in the axial direction of the pressure member 4, that is, the vertical direction in the figure, and is continuously formed on the entire periphery along the outer peripheral surface 4d. It is provided with dimensions such that it is in sliding contact with the side walls 2b and 2c of the cylindrical chamber 2 formed by the inner surface of the case 1a and the lid 1b.

  The tube pump of this embodiment is configured as described above, and sufficient lubricant 8 is applied to the tube 3, and the inner peripheral surface 2a, side walls 2b, 2c of the cylindrical chamber 2 around the tube 3 and the outer ring. The outer peripheral surface 4d of 4b is assembled with the lubricant 8 attached thereto. When the pump is operated, the pressurizing member 4 moves eccentrically, and the tube 3 is sequentially pressed in one direction to perform the pump action. When the tube 3 is compressed and flattened as shown on the left side of FIG. 1, the lubricant 8 applied to the tube 3 and its periphery escapes in the longitudinal direction of the tube 3, or the pressure member 4 and the side walls 2b and 2c. There is no choice but to escape from the gap toward the center of the cylindrical chamber 2. However, since the ear piece 11 slides in contact with the side walls 2b and 2c, the ear piece 11 is closed between the side walls 2b and 2c. It remains in the periphery of the tube 3 without being pushed out toward the center, and the lubricating action is maintained for a long time.

  FIG. 2 is a cross-sectional view of the main part of the second embodiment, and includes a first ear piece 11a formed on the outer peripheral side and a second ear piece 11b formed on the inner peripheral side of the ear piece 11a. The ear piece has a double structure. That is, the first ear piece 11a is formed on both side edges of the outer peripheral surface 4d of the outer ring 4b in the same manner as in FIG. 1, and the second ear piece 11b is formed with a smaller diameter so that each ear piece 11a, 11b is cylindrical. The side walls 2b and 2c of the chamber 2 are in sliding contact with each other, and a lubricant groove 11c is formed between the ear pieces 11a and 11b.

  In this embodiment, the outer ring 4b is shaped as described above, and when the tube 3 is compressed, the lubricant 8 passes through the sliding contact portion between the first ear piece 11a and the side walls 2b and 2c and reaches the collecting groove 11c. Even if there is, the lubricant 8 can freely move in the pool groove 11c, so that the pressure during compression is reduced. For this reason, a high pressure that passes through the sliding contact portion between the second ear piece 11b and the side walls 2b and 2c and is pushed out toward the central portion of the cylindrical chamber 2 is not applied to the lubricant 8, and the lubricant 8 It stays around the tube 3.

  FIG. 3 is a cross-sectional view of the main part of the third embodiment. The left side shows the side where the tube is compressed, and the right side shows the side where the tube is not compressed. In this embodiment, the ear piece has a double structure as in the case of FIG. 2, but the first ear piece 11a has a shape that is easy to bend and the second ear piece 11b has a shape that is difficult to bend. is there. As shown on the left side of the figure, when the tube 3 is compressed, the ear piece 11a is bent in the direction of the accumulation groove 11c due to the pressure generated by the compression, and a gap is formed in the sliding contact portion. However, a high pressure that pushes out toward the central portion of the cylindrical chamber 2 is not applied to the lubricant 8, and the lubricant 8 remains in the accumulation groove 11c. And when the pressure is lost, the ear piece 11a bends in the outer peripheral direction as the pressure member 4 moves in the center direction, and the lubricant 8 attached to the side walls 2b, 2c is maintained in the attached state as it is, As a result, the lubricant 8 stays around the tube 3.

  FIG. 4 shows an example in which a plurality of notches 11d are provided in the first ear piece 11a when the ear piece has a double structure as in the second and third embodiments. Are provided at intervals of 120 °. In this way, when a plurality of cutouts 11d are provided, the lubricant 8 pushed up to the accumulation groove 11c by the compression passes through the other cutouts 11d in the uncompressed portions and passes through the tube 3 side. Therefore, the pushing out toward the central portion of the cylindrical chamber 2 is less likely to occur.

  The present invention can be applied to various tube pumps.

It is a schematic sectional drawing of one Example of this invention. It is a schematic sectional drawing of the principal part of another Example. It is a schematic sectional drawing of the principal part of another Example. It is a top view of the pressurization member of other examples.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Cylindrical chamber 2a Inner peripheral surface 2b, 2c Side wall 3 Tube 4 Pressure member 4b Outer ring 8 Lubricant 11, 11a, 11b Ear piece 11c Reservation groove 11d Notch

Claims (4)

The tube ring is arranged in a ring shape along the inner peripheral surface of the cylindrical chamber formed in the housing body, and the pressure member provided inside the tube is moved eccentrically along the inner peripheral surface. In the tube pump that sends the fluid in the tube by sequentially pressing the shape part in one direction,
An ear piece protruding in the axial direction of the pressurizing member is formed in a ring shape on the outer peripheral side edge of the pressurizing member made of an elastic material, and this ear piece is slidably contacted with the side wall of the cylindrical chamber to place the tube in the center of the cylindrical chamber. A tube pump configured to seal against a portion . The ear piece includes a first ear piece formed on the outer peripheral side and a second ear piece formed on the inner peripheral side of the first ear piece. The first ear piece and the second ear piece 2. The tube pump according to claim 1, wherein a groove for storing a lubricant is formed between the ear pieces. The tube pump according to claim 2, wherein the first ear piece is easily bent and the second ear piece is not easily bent. The tube pump according to claim 2 or 3, wherein a plurality of notches are provided in the first ear piece.

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