JP2008069746A - Squeeze type pump and pumping tube attaching method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pumping tube exhibiting excellent durability by adjusting thickness, and capable of correcting the twist of the tube when attaching to a casing, and a squeeze type pump attached with it. <P>SOLUTION: In the pump tube 3 of the squeeze type pump attached in a curved state in such a manner of being brought into contact with the inside of the casing 1 having a cylindrical inner peripheral surface and constituted so as to suck liquid from one end side and deliver the liquid from the other end side, a tube inside diameter center 3a is eccentric with respect to a tube outside diameter center 3b, and a thick part 18 which is the thickest is positioned on the innermost side of a bending radius direction R of the pumping tube 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a squeeze pump for conveying fluid such as ready-mixed concrete and mortar.

  The basic structure of a squeeze pump that transports ready-mixed concrete will be described. As described in Patent Document 1, the squeeze pump includes a casing having a cylindrical inner peripheral surface, a cushion rubber pad provided along the inner peripheral surface of the casing, and a U-shape along the rubber pad. The pumping tube having elasticity arranged in a shape, a rotating body installed concentrically with the center of the inner peripheral surface of the casing, and a roller that is supported by the rotating body and rotates while pressing the pumping tube.

  Both ends of the pumping tube protrude from the casing, and one end serves as a suction port connected to the hopper, and the other end serves as a discharge port connected to the transfer pipe. When the roller moves while pressing the pumping tube, the pumping action is generated in the pumping tube by the pressing action of the roller and the restoring action of the pumping tube. By this pumping action, the ready-mixed concrete can be sucked from the suction port side of the pumping tube and discharged from the discharge port at the other end.

  Since the pumping tube is pressed by a roller, excellent flexibility is required, but durability against internal pressure generated by the pump action is also required. Therefore, a pumping tube having a structure in which a rubber tube is reinforced with a reinforcing cord such as a steel cord is generally used.

Explaining the structure of the pumping tube, the pumping tube generally includes an inner rubber layer and an outer rubber layer as rubber layers, and is formed of a reinforcing cord and a covering rubber covering the reinforcing cord between the two rubber layers. A reinforcing layer is interposed. The reinforcing cord is disposed so that the outer periphery of the inner rubber layer is wound spirally.
JP-A-2005-273526

  By the way, the pumping tube having the above configuration is worn out by the fluid flowing in the tube, and therefore needs to be replaced. Therefore, in order to increase the durability of the pumping tube, it is preferable that the wear occurs evenly with the pumping tube mounted on the casing.

  Further, when the pumping tube is attached to the casing in a state of being twisted around the central axis, an excessive force is applied to the reinforcing layer, and the pressure resistance of the pumping tube is lowered. Therefore, when installing the tube, it is necessary to carefully work while observing the twist of the tube, and when the twist occurs, it is necessary to perform a correction work by a machine, which is complicated and troublesome. Has occurred.

  Therefore, the present invention provides a squeeze type pump having excellent durability by adjusting the thickness of the pumping tube, and further, mounting of the pumping tube capable of correcting tube twisting when mounted on the casing. The purpose is to provide a method.

  As a result of various studies by the present inventors, when the pumping tube 3 having a constant thickness is mounted on the casing, as shown in FIG. 13, the thickness of the mounted pumping tube 3 is the outer side in the tube bending radius direction R ( In T1) and radially inner side (T2), the outer side becomes larger, so that T2> T1. However, since the tube portion (thickness T2) located inside the bending radius direction R is deformed and stretched when pressed by the roller 5, the tube thickness (thickness t) of the portion is the outer portion in the bending radius direction R. It becomes thinner than (T1) (T1> t).

 Therefore, if the thickness of the pumping tube is the same between the outer side and the inner side in the bending radius direction, the durability is reduced by the thickness of the tube portion (T2) on the inner side in the bending radius direction when it is pressed by the roller. As a result, the present invention was completed.

  That is, in the present invention, a rotating body that is installed concentrically with the center of the inner peripheral surface by making a curved pumping tube (hereinafter abbreviated as a tube) inscribed in a casing having an inner peripheral surface formed in a cylindrical shape. In the squeeze pump that discharges the fluid in the tube by sequentially compressing the tube in the length direction by the rotating body, the tube inner diameter center is eccentric with respect to the tube outer diameter center. It is characterized in that the thickest wall portion that is the thickest is disposed so as to be located on the innermost side in the bending radius direction of the tube.

  In the above tube, by decentering the tube inner diameter center with respect to the outer diameter center, the tube thickness continuously changes in the tube circumferential direction, and the thinnest part and the thickest part are opposed to each other. The thin wall portion, the thick wall portion, and the tube center axis are formed in the same plane. Therefore, it is possible to mount the thick part on the casing so as to be located on the innermost side in the bending radius direction of the tube over the entire length of the tube.

  Therefore, according to the above configuration, the thick part comes into contact with the roller, so that even when the tube part pressed by the roller is deformed and extended, the tube thickness is prevented from being thinner than other tube parts. Thus, the durability of the tube and thus the squeeze pump can be improved.

  The tube used in the squeeze pump according to the present invention can be cylindrical on both the inner surface and the outer surface. Further, by making the outer surface cylindrical and the inner surface tapered toward the discharge side of the squeeze pump, the flow velocity of the fluid can be increased at the discharge side end of the pump. Furthermore, both the inner and outer surfaces of the tube have a tapered truncated cone shape toward the discharge side of the squeeze pump, so that the flow rate at the discharge side end of the pump is increased while the tube at the discharge side end is excessive. Therefore, it becomes possible to prevent the discharge pressure from being lowered due to the increase in the wall thickness and the obstruction of the tube.

  In the present invention, the degree of uneven thickness is expressed by the uneven thickness ratio (%) = (thick part thickness−thin part thickness) × 100 / thick part thickness. It is possible to improve the durability of the squeeze pump by preventing the thick portion from becoming thin when the tube is pressed.

  When the uneven thickness ratio is further increased, the thin part is easy to bend and the thick part is difficult to bend.Accordingly, the tube is accommodated in the casing so as to be rotatable around the central axis of the tube, and when the tube is sequentially pressed with a roller, The aligning action is exhibited such that the thin wall portion is oriented outward in the bending radius direction of the tube and the thick wall portion is oriented inward of the bending radius direction of the tube. Therefore, if an eccentric tube whose tube inner diameter center is eccentric with respect to the tube outer diameter center is used, it can be easily mounted on the casing while suppressing twisting.

  In order to exhibit the aligning action, the thickness deviation rate is preferably 7% to 25%, and more preferably 10% to 20%. If it is this range, it will become possible to exhibit a centering effect effectively, suppressing the increase in the load concerning a roller at the time of the tube press by a roller. Thereby, it becomes possible to prevent the fall of the pressure resistance and durability of a tube, and the squeeze type pump excellent in durability can be obtained.

  A specific method for mounting the tube on the casing while suppressing twisting is as follows. That is, a U-shaped curved pumping tube is inscribed in a casing having a cylindrical inner peripheral surface, and both ends of the pumping tube protrude from a discharge side opening and a suction side opening formed in the casing, respectively. A tube tip protruding from the side opening is connected to the fluid transfer pipe, a tube rear end protruding from the suction side opening is connected to the fluid supply means, and a rotating body installed concentrically with the center of the inner peripheral surface is connected to the tube rear end. Pumping a squeeze pump that discharges fluid in the tube by sequentially rotating the pumping tube in the length direction by a roller provided rotatably at the tip of the rotating body by rotating it forward from the side toward the tube tip side A tube mounting method, wherein the pumping tube is an eccentric tube in which the tube inner diameter center is eccentric with respect to the tube outer diameter center, The pumping tube is introduced into the casing from the suction side opening so that the thinnest part of the tube is in contact with the inner peripheral surface of the casing, and the rear end of the tube is connected to the fluid supply means when the tube tip approaches the fluid transfer pipe. Then, by rotating the rotating body in the reverse direction, the tube tip is sent out toward the fluid transfer tube while correcting the twist of the tube in the tube length direction, and the tube tip is connected to the fluid moving tube. is there.

  In the present invention, as the pumping tube of the squeeze pump, the tube inner diameter center is eccentric with respect to the tube outer diameter center, and the thickest wall portion is located on the innermost side in the bending radius direction of the pumping tube. Even if the tube part pressed by the roller is deformed and stretched, it prevents the tube thickness from becoming thinner than other tube parts and improves the durability of the squeeze pump. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a squeeze pump according to the present invention.

  As shown in FIG. 1, the squeeze pump in the present embodiment is for transferring ready-mixed concrete, and has a casing 1 having a cylindrical inner peripheral surface and a cushion fixed along the inner peripheral surface of the casing 1. Rubber pad 2, a pumping tube 3 arranged in a U shape along the rubber pad 2, a rotor 4 as a rotating body installed concentrically with the center of the inner peripheral surface of the casing 1, It is comprised from the roller 5 supported by the front-end | tip and pressing the pumping tube 3, and fresh concrete passes through the inside of the pumping tube 3 as a fluid.

  A suction-side opening 6 and a discharge-side opening 7 are formed on the peripheral wall of the casing 1, and a suction port 8 formed at the rear end of the tube protrudes from the suction-side opening 6, and is formed at the tip of the tube from the discharge-side opening 7. The discharge port 9 protrudes. The suction port 8 of the pumping tube 3 is connected and fixed to a hopper 10 as fluid supply means, and the discharge port 9 of the pumping tube 3 is connected and fixed to a concrete transfer tube 11 as a fluid transfer tube. Further, the casing 1 is configured to be able to be sealed so that there is no gap between the suction side opening 6 and the discharge side opening 7 and the pumping tube 3, and the inside of the casing 1 is kept in a vacuum state.

  Two rollers 5 are provided on the rotor 4 while being shifted by 180 °. When the rotor 4 rotates in the clockwise direction (arrow P direction) from the tube rear end side to the tube tip side, that is, from the suction port 8 side to the discharge port 9 side, the rotation is reversed. If the rotation is reversed, the roller 5 rolls while pressing the pumping tube 3 toward the rubber pad 2 at the time of normal rotation, so that the pumping tube 3 is pressed by the pressing action of the roller 5 and the restoring action of the pumping tube 3. Thus, a pumping action occurs, and a fluid such as concrete in the hopper 10 can be sucked from the suction side and transferred to the discharge side. At this time, the roller 5 rotates.

  2 is a cross-sectional view schematically showing the pumping tube 3. FIG. 2 (a) is a cross-sectional view in the tube length direction, and FIG. 2 (b) is a cross-sectional view in the radial direction of the tube. As shown in FIG. 2A, the pumping tube 3 has an inner surface and an outer surface formed in a tapered truncated cone shape from the suction port 8 side to the discharge port 9 side, as shown in FIG. Thus, the tube inner diameter center 3a is eccentric with respect to the tube outer diameter center 3b. Thereby, the thick part 18 and the thin part 19 are formed in the position which opposes 180 degrees in a tube circumferential direction. That is, the pumping tube 3 is formed such that the thin portion 19, the thick portion 18 and the tube center axis X are included in the same plane.

  The pumping tube 3 includes an inner rubber layer 13, a reinforcing layer 14 disposed on the outer peripheral side of the inner rubber layer 13, and an outer rubber layer 15 disposed on the outer peripheral side of the reinforcing layer 14. That is, the pumping tube 3 includes an inner rubber layer 13 and an outer rubber layer 15 and a reinforcing layer 14 interposed between the rubber layers 13 and 15. The reinforcing layer 14 includes a reinforcing cord and a covering rubber that covers the reinforcing cord.

  The pumping tube 3 is attached to the casing 1 such that the thick portion 18 is located on the innermost side in the bending radius direction R of the tube. In other words, the thin portion 19 is mounted so as to be located on the outermost side in the bending radius direction R of the tube. Thereby, even when the tube part pressed by the roller is deformed and stretched, it is possible to prevent the tube thickness from becoming thinner than other tube parts, thereby improving the durability of the pumping tube.

  An example of a method for manufacturing the pumping tube 3 will be described. First, as shown in FIG. 3, a mandrel 24 having a shape in which the rotating shaft 21 is eccentric with respect to the central axis 23 of the mandrel body 22 is prepared. And as shown in FIG. 4, the extrusion apparatus 27 which extrudes the inner surface rubber 25 and the outer surface rubber mentioned later in the direction orthogonal to the rotating shaft 21 direction of the mandrel 24 is installed.

  Next, the unvulcanized inner rubber 25 is extruded from the extrusion device 27 in the circumferential direction of the mandrel 24 while rotating the rotating shaft 21. When the inner rubber 25 is extruded, the mandrel 24 and the extruding device 27 are moved relative to the direction of the rotating shaft 21. As a result, the inner rubber 25 is spirally wound around the outer periphery of the mandrel 24.

  At this time, since the rotating shaft 21 is eccentric with respect to the mandrel main body 22, the distance L from the center of the rotating shaft 21 to the outer surface of the mandrel is L1 at the shortest and L2 at the longest. Then, as shown in FIG. 4, the peripheral speed when the mandrel 24 rotates is the fastest when the distance L is L2 (S2). As shown in FIG. 5, the peripheral speed of the mandrel is the slowest when the distance L is L1 (S1).

  Assuming that the amount of the inner rubber discharged from the extrusion device 27 is constant, the inner rubber 25 wound around the outer surface of the mandrel is thickest on the L1 side and thinnest on the L2 side as shown in FIG. In this way, the inner rubber layer 13 can be formed to have a thickness that continuously changes in the tube circumferential direction.

  After the inner rubber 25 is wound around the mandrel outer peripheral surface to form the inner rubber layer 13, the reinforcing layer 14 is formed on the outer periphery of the inner rubber layer 13 as shown in FIG. The reinforcing layer 14 is formed by winding a rubber-coated cord around the outer periphery of the inner rubber layer 13. The rubber-coated cords are alternately wound in a plurality of layers so that the cord directions intersect at a predetermined forming angle with respect to the axis of the pumping tube 3. In this embodiment, the reinforcing layer 14 has a two-layer structure in which two rubber-coated cords are wound.

  After the reinforcing layer 14 is formed, the outer rubber layer 15 is formed as shown in FIG. 8 by winding the unvulcanized outer rubber discharged from the extrusion device 27 around the outer periphery thereof. 3 to 8 schematically show that the rotating shaft 21 is eccentric with respect to the central shaft 23 of the mandrel main body 22, and actually the rotating shaft 21 is centered. A position closer to the shaft 23 is set. Specifically, for example, when the ratio of the thickness of the thick part / thin part is 1.2, the rotation shaft 21 is set at a position where the value of L2 / L1 in FIG.

  Therefore, in FIG. 6, the center of the outer peripheral surface of the mandrel in the state where the inner rubber layer 13 is formed substantially coincides with the rotation shaft 21, and the peripheral speed of the mandrel becomes constant. The reinforcing layer 14 and the outer rubber layer 15 formed on the outer peripheral side have a substantially constant thickness in the circumferential direction.

  The pumping tube 3 can be obtained by vulcanizing the unvulcanized rubber obtained as described above. In the present embodiment, the eccentric mandrel 24 is used. However, the present invention is not limited to this, and for example, an extrusion apparatus including a crosshead can be used.

  A method of mounting the pumping tube 3 thus obtained on the casing 1 will be described. As shown in FIG. 9, the pumping tube 3 is inserted from the suction side opening 6 of the casing with the discharge port 9 side at the head. At this time, the thin tube portion 19 of the pumping tube 3 is inserted on the outermost side in the bending radius direction R of the pumping tube, and the thick portion 18 is inserted on the innermost side in the bending radius direction R.

  With the distal end portion of the pumping tube 3 inserted into the casing 1, the rotor 4 is rotated forward (direction P). At this time, by inserting the pin 28 into the rotor 4 so that the roller 5 does not rotate, the pumping tube 3 is pulled into the casing 1 by its frictional force while being pressed by the roller 5.

  When the front end of the pumping tube 3 approaches the concrete transfer pipe 11, the suction port 8 at the rear end of the tube is connected to the hopper 10 as shown in FIG. In addition, when connecting the tube 3 to the hopper 10, the thin part 19 of the pumping tube 3 is made to be on the outermost side in the bending radius direction R of the pumping tube.

  Then, when the pin 28 that has fixed the roller 5 is removed to make the roller 5 rotatable, and the rotor 4 is rotated in the reverse direction (direction Q), the roller 5 presses the pumping tube 3 toward the rubber pad. Roll while. Thus, by making the roller 5 rotatable and rotating the rotor 4 in the reverse direction, the tube 3 moves forward gradually toward the concrete transfer pipe 11 while pulsating, and is adjusted by the uneven thickness structure of the tube 3. A heart effect is exhibited, and the thin-walled portion 19 is oriented outside the bending radius direction R of the tube over the entire length of the tube 3 to suppress twisting.

  Finally, as shown in FIG. 11, if the discharge port 9 of the tube 3 is connected to the concrete transfer pipe 11 when the pumping tube 3 reaches the concrete transfer pipe 11, the pumping tube 3 is attached to the casing 1. Is completed.

  The degree of twist when the pumping tube was mounted on the casing of the squeeze pump by the mounting method according to the present invention and the life of the pump when concrete was placed in that state were evaluated.

  Specifically, using the eccentric mandrel, a tapered truncated cone-shaped pumping tube was produced toward the tube tip on both the inner and outer surfaces of the tube. The outer diameter of the tube at the suction port 8 side end face was 173 mm, the thickness of the thick portion was 20 mm, and the thickness of the thin portion was 17 mm. Further, the tube outer diameter at the discharge port 9 side end surface was 163 mm, the thickness of the thick portion was 26.5 mm, the thickness of the thin portion was 22.5 mm, and the total length was 3500 mm (thickness ratio 15%). This pumping tube was mounted on the casing 1 having an inner diameter of 1200 mm using the pumping tube mounting method according to the present invention (product of the present invention).

  On the other hand, as a comparison product, the pumping tube has a total length of 3500 mm, the tube outer diameter at the suction port 8 side end surface is 173 mm, the tube thickness is constant at 18.5 mm, and the tube outer diameter at the discharge port 9 side end surface is 163 mm. Is 24.5 mm constant, that is, the thickness deviation rate is 0%. This was mounted on the casing in the same manner as the product of the present invention.

  As shown in FIG. 12, the evaluation method of the twist is 0 ° when the position of the thin portion 19 in the discharge port 9 of the pumping tube 3 is located at the outermost side in the bending radius direction R of the tube 3. Whether it was twisted (angle α) was measured. In measuring the torsion, a linear mark was put on the thin portion 19 in advance on the outer periphery of the tube, and the measurement was performed based on the position of the mark. The results are shown in Table 1.

  As shown in Table 1, in the products of the present invention, the twist angle α of less than 3 ° accounted for the majority of 90%, whereas in the comparative product, the ratio of less than 3 ° remained at 60%. Further, in the product of the present invention, there was no twist of 5 ° or more, whereas in the comparative product, 10% of the twist was 5 ° or more. It turned out to be suppressed.

  Furthermore, as a result of placing concrete in the above-mentioned mounting state, it was found that when the life of the comparative product was set to 100, the life of the product of the present invention was improved to 125% on average.

Schematic showing a squeeze pump according to the present invention It is sectional drawing which shows the outline of a pumping tube, Fig.2 (a) shows sectional drawing of a tube length direction, FIG.2 (b) shows sectional drawing of the radial direction of a tube. The perspective view which shows typically the mandrel used for manufacture of a pumping tube The schematic diagram which shows the state which extrudes and winds rubber | gum from the extrusion apparatus to the mandrel of FIG. Schematic diagram showing the state when the mandrel rotates in FIG. Side view of the mandrel schematically showing the state of forming the inner rubber 6 is a side view of the mandrel schematically showing a state in which a reinforcing layer is further formed in FIG. FIG. 7 is a side view of a mandrel schematically showing a state in which an outer rubber layer is further formed. Schematic showing the state of inserting the pumping tube into the casing FIG. 9 is a schematic view showing a state where the pumping tube is further inserted into the casing. Schematic showing the pumping tube mounted on the casing Schematic showing twist of pumping tube Sectional drawing which shows the thickness of each part of the pumping tube at the time of roller press

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Rubber pad 3 Pumping tube 4 Rotor 5 Roller 6 Suction side opening 7 Discharge side opening 8 Suction port 9 Discharge port 10 Hopper 11 Concrete transfer pipe 13 Inner surface rubber layer 14 Reinforcement layer 15 Outer surface rubber layer 18 Thick part 19 Thin part 21 Rotating shaft 22 Mandrel body 23 Central axis of mandrel body 24 Mandrel 25 Internal rubber 27 Extrusion device 28 Pin

Claims (4)

A curved pumping tube is inscribed in a casing having an inner peripheral surface formed in a cylindrical shape, and a rotating body installed concentrically with the center of the inner peripheral surface is rotated, whereby the pumping tube is rotated by the rotating body. In the squeeze pump that discharges the fluid in the tube by sequentially compressing the tube in the length direction, the pumping tube has an inner diameter center that is eccentric with respect to the tube outer diameter center, and a thickest portion that is thickest. A squeeze pump characterized by being arranged so as to be located on the innermost side in the bending radius direction of the pumping tube. The squeeze pump according to claim 1, wherein both the inner surface and the outer surface of the pumping tube have a truncated cone shape. The squeeze pump according to claim 1 or 2, wherein the pumping tube has an uneven thickness ratio of 7% to 25%. A pumping tube curved in a U-shape is inscribed in a casing having a cylindrical inner peripheral surface, and both ends of the pumping tube protrude from a discharge side opening and a suction side opening formed in the casing, respectively, and a discharge side opening The tube tip protruding from the tube is connected to the fluid transfer pipe, the tube rear end protruding from the suction side opening is connected to the fluid supply means, and the rotating body installed concentrically with the center of the inner peripheral surface is connected from the tube rear end side. A squeeze pump pumping tube is mounted so that the roller that rotates freely at the tip of the rotating body pushes the pumping tube in the length direction in order to discharge the fluid in the tube by rotating it forward toward the tube tip. The pumping tube is an eccentric tube in which the tube inner diameter center is eccentric with respect to the tube outer diameter center. The pumping tube was introduced into the casing from the suction side opening so that the thinnest part of the thin wall was in contact with the inner peripheral surface of the casing, and the tube rear end was connected to the fluid supply means when the tube tip approached the fluid transfer pipe. Thereafter, the squeeze pump is characterized in that by rotating the rotating body in the reverse direction, the tube tip is sent out toward the fluid transfer tube while correcting the twist of the tube in the tube length direction, and the tube tip is connected to the fluid transfer tube. How to install a pumping tube.

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