JP2015224606A - Cooling structure of squeezing type pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of a squeezing type pump capable of preventing damage of a rubber pad due to excessive displacement while cooling a contact portion of the rubber pad and a pumping tube at low cost.SOLUTION: A cooling structure of a squeezing type pump includes a hole part 25 that penetrates a rubber pad 6 and is opened on a surface 6a of the rubber pad 6, and a tank 27 that holds cooling water to the outside of a pump case 5 and communicates with the hole part 25. A pumping tube 7 performs contact/separation to the surface 6a of the rubber pad 6 by deflection depending on rolling of a roller 19, and the hole part 25 is opened/closed to the inside of the pump case 5 by the contact/separation of the pumping tube 7.

Description

  The present invention relates to a cooling structure for a squeeze pump that pumps fluid such as ready-mixed concrete.

  A squeeze pump (squeeze pump) is often used especially for pumping fluids containing solids, and in particular for pumping of ready-mixed concrete (hereinafter referred to as “ready kon”), the mechanism itself is easy to use. Widely used mainly for in-push distance pumping.

  As a squeeze-type pump, for example, a pump case in which a rubber pumping tube is bent in a pump case and a roller is disposed inside the pumping tube so that the roller can roll is known (for example, Patent Documents). 1).

  In this tied-up pump, the roller rolls while pressing the pumping tube from the inside of the curve, so that the pumping tube is sequentially crushed with the inner surface of the pump case, thereby sucking from one end of the pumping tube The fluid can be discharged and pumped out from the other end.

  In the squeeze pump, the pumping pressure is obtained by pressing the pumping tube with a roller, and the contact pressure (seal pressure) between the inner surfaces due to the crushing of the pumping tube is higher than the pumping pressure. Pumping is realized.

  The sealing pressure is generally required to be about 1.2 to 1.5 MPa that generates a pumping pressure of about 1 MPa. The pressing force at this time is increased to about 2.0 MPa which is higher than the sealing pressure.

  Here, on the inner surface of the pump case, when the pumping tube is pressed by the roller, the cushioning material and the position fixing material of the pumping tube are used so that the surface pressure between the roller and the entire pumping tube is received as uniformly as possible. A rubber pad is arranged.

  While the rubber pad is in contact with the outer surface of the pumping tube that repeatedly receives high pressure, the rubber pad generates high heat due to pressure applied via the pumping tube by the roller and sliding between the pumping tube.

  The heat generation is proportional to the pumping pressure and the usage time, and the rubber pad has a relationship with the heat generation. For example, the continuous operation up to 2 hours when the pumping pressure is about 1.0 MPa for 3 hours and 1.5 MPa is the limit in actual use. Met.

  If the pumping pressure and continuous operation time are higher than this, the rubber pad will be cracked by heat generation, deteriorated in physical properties or cured due to thermal deterioration, and the rubber pad will not be usable, and the pumping tube in contact with it will be damaged. There was a problem.

  On the other hand, in recent years, the strength of concrete has been increased for earthquake resistance of buildings. However, compared to the conventional concrete installation, a pumping pressure of about 20% can be achieved by simply placing it at a conventional height or distance. It is growing. Further, in order to save labor and shorten the time, high-speed (high-pressure) placement for a short time and small-diameter piping are required. For this reason, there has been a strong demand for the squeeze pump to enable high-pressure and long-time operation at least within the required range.

  Therefore, as a conventional squeeze-type pump, there is a pump as shown in Patent Document 2 in which vent holes are provided in each part of the pump case to dissipate heat generated in the pump case when the live control unit is placed to cool the air.

  However, in the squeeze type pump, generally, the inside of the pump case is evacuated to promote the restoration after the pumping tube is crushed, and the pumped tube is smoothly sucked into the next pumped raw concrete. ing.

  For this reason, the system of patent document 2 cannot be applied to a squeeze pump (vacuum type) that evacuates the inside of such a pump case.

  Further, in the method of Patent Document 2, since the suction of the raw container to be pumped next depends only on the restoring force of the pumping tube itself, it is necessary to make the pumping tube harder and thicker. The pressing load of the roller against the tube also increases.

  For this reason, since the heat generated by repeated crushing of the pumping tube during continuous operation of the squeeze pump is larger than that of the vacuum type, it is originally unsuitable for high pressure and long time use.

  In addition, the method of Patent Document 2 is likely to generate heat in the pumping tube even in low pressure use, and there is an effect of cooling the inside of the pump case, but most of the heat generation between the pumping tube and the rubber pad is low pressure use. Since it was in close contact and there was little air flow, the actual cooling effect was small.

  Patent Document 3 discloses a squeeze pump that is not a vacuum type, and reduces the heat generation by reducing the coefficient of friction between the rubber pad and the pumping tube and between the pumping tube and the roller by supplying lubricating oil. It is disclosed.

  Although the method of Patent Document 3 can be applied to a vacuum type, the function as a rubber pad position fixing material, that is, the function of a rubber pad that prevents the pumping tube from being displaced when pressed by a roller by closely contacting the pumping tube. It was an obstacle.

  Therefore, in the method of Patent Document 3, the pumping tube is inadvertently meandered in the pump case in accordance with the change in the pressing position with respect to the pumping tube due to the rolling of the roller, and a desired discharge pressure (pressure feed pressure) or discharge amount (pressure feed). Have the basic problem of not being able to achieve. This becomes more remarkable in a high pressure state where the pumping pressure exceeds 1.5 MPa.

  Furthermore, in the method of Patent Document 3, even if the lubricating oil is supplied to the portion where the heat generation is the largest between the pumping tube and the rubber pad, the lubricating oil is scattered in each part of the pump case according to the rolling of the roller. Become.

  As a result, the lubrication effect (friction coefficient reduction effect) that can prevent the heat generation of the rubber pad and pumping tube is obtained only in the initial stage, and after a few hours of operation, the lubricating oil functions exclusively as a rubber pad position fixing material. It was an obstacle.

  In addition, the lubricating oil adheres to the internal mechanism of the pump case as a whole due to scattering, which greatly impedes maintenance work and has an adverse effect on cooling.

  On the other hand, Patent Document 4 discloses a vacuum type that reduces heat generation by reducing the coefficient of friction between the rubber pad and the pumping tube without using lubricating oil.

  In the method of Patent Document 4, aramid short fibers or carbon short fibers are mixed in the outer layer of a rubber pumping tube, and the short fibers are interposed on the friction sliding surface with the rubber pad.

  Thereby, in the system of patent document 4, the friction coefficient between a rubber pad and a pumping tube can be lowered | hung, and the heat_generation | fever between both can be reduced. For example, in actual use, when continuous operation is performed for 3 hours at a pumping pressure of 1.5 MPa, the heat generation between the rubber pad and the pumping tube is reduced from 130 ° C. when no short fibers are present to 100 ° C. Can do.

  However, during continuous operation of the squeeze pump, heat deterioration of the rubber pad and the pumping tube is inevitable due to repeated heat generation at 100 ° C. between the rubber pad and the pumping tube, and the heat history being accumulated.

  In a severe heat environment of 100 ° C for rubber products, a predetermined clearance between the roller and the rubber pad (between the roller and the rubber pad) is caused by a decrease in the spring property as a compression spring, which is one of the basic physical properties of rubber. ) Cannot be maintained, and the sealing pressure of the pumping tube decreases. As a result, there has been a problem that the long-time high pressure, for example, about 2 MPa is hindered.

  Moreover, carbon short fibers require special equipment and technology for mixing with rubber, and the technical problem of being cut and powdered at the time of mixing is still unresolved. Only aramid short fibers are used.

  However, aramid short fibers are not only expensive per se, but also require special mixing equipment and techniques, and as a result, pumping tubes are very expensive.

  Furthermore, the pumping tube using the rubber mixed with short aramid fibers cannot be bonded to the aramid short fiber mixed rubber only in the portion where the outer layer is easily worn, and the aramid short fiber mixed rubber is disposed over the entire outer surface. It was also an expensive factor to have an unreasonable configuration.

  On the other hand, in Patent Document 5, as a technique for reducing heat generation between the rubber pad and the pumping tube at a low cost, there is a technique in which rubber is removed from the central portion of the rubber pad and a steel material is provided in that portion. As a result, the friction coefficient between the rubber pad and the pumping tube can be lowered and the steel material can be used as a heat sink, and the heat generation between the two can be reduced.

  However, the rubber pad as the cushioning material is necessary for the entire surface in contact with the pumping tube with cushioning performance. That is, since the highly rigid steel material has no cushioning property, the cushioning property of the rubber pad in the vicinity thereof, that is, the displacement amount is remarkably increased. As a result, the rubber pad was subject to repeated excessive displacement in the vicinity of the steel material, resulting in early breakage.

  As described above, the method of Patent Document 5 can prevent heat generation and dissipate heat, but has a new problem of breaking the rubber pad at an early stage.

  Of course, the effect of the steel material on the pumping tube is also great, and the effect of mitigating the displacement along the pumping tube axis is lost. Therefore, the problem that the wear of the inner surface of the pumping tube occurs early along the pumping tube axis also occurred.

JP 2008-115826 A Japanese Patent Laid-Open No. 09-014156 Japanese Patent Laid-Open No. 10-231787 No. 07-034218 JP 09-049490 A

  The problem to be solved is that if the contact portion between the rubber pad and the pumping tube is cooled at a low cost, the rubber pad is easily damaged by excessive displacement.

  The present invention enables the cooling of the contact portion between the rubber pad and the pumping tube at a low cost and prevents the rubber pad from being damaged due to excessive displacement. A cooling structure for a squeeze-type pump that allows a fluid to be pumped by supporting a flexible pumping tube so that it can be separated by contact and pressing it by rolling of a roller. The surface of the rubber pad penetrates the rubber pad. A hole that opens upward, and a coolant supply source that holds the coolant outside the pump case and communicates with the hole, and the pumping tube is bent by the bending of the roller. The hole is in contact with and separated from the surface of the rubber pad, and the hole portion is separated from the inside of the pump case by the contact and separation of the pumping tube. The most main features to be closed.

  In the cooling structure of the present invention, the contact portion between the pumping tube and the rubber pad is automatically sucked from the coolant supply source by utilizing the contact separation operation when the pumping tube is pressed by the roller and the pressure reduction in the pump case. Cooling in between can be realized at low cost.

  Moreover, since the rubber pad only needs to be provided with a hole, there is no local excessive displacement when the pumping tube is pressed by the roller, and there is no damage due to repeated such excessive displacement.

It is a side view which shows schematic structure of the pump vehicle which has a squeeze-type pump (one Example). It is sectional drawing which shows the whole structure of the squeeze-type pump of FIG. 1 (one Example). It is a principal part expanded sectional view of the squeeze-type pump of FIG. 2 (one Example). FIG. 4 is a sectional view taken along line IV-IV in FIG. 3 (one example). It is principal part sectional drawing which shows the cooling operation of the squeeze-type pump of FIG. 2 (one Example). It is a graph which shows the relationship between a vacuum degree and the boiling point of water (one Example). It is a principal part enlarged view which shows the hole periphery vicinity of the rubber pad corresponding to FIG. 4 (one Example). It is a graph which shows a cooling effect with a comparative example (one Example).

  For the purpose of preventing damage to the rubber pad due to excessive displacement while inexpensively cooling the contact portion between the rubber pad and the pumping tube, a hole is provided in the rubber pad provided on the inner surface of the pump case where the inside is decompressed, This is realized by a cooling structure of a squeeze pump in which a coolant supply source that holds coolant outside the pump case is communicated with the hole.

[Configuration of squeeze pump]
FIG. 1 is a side view showing a schematic configuration of a pump vehicle having a squeeze pump, and FIG. 2 is a cross-sectional view showing the overall configuration of the squeeze pump in FIG.

  As shown in FIG. 1, the squeeze pump 1 according to the present embodiment is a movable pump provided in a pump car 3 for pumping ready-mixed concrete (hereinafter referred to as “ready kon”) as a fluid. However, the squeeze pump 1 can be used as a stationary type or the like.

  As shown in FIG. 2, the squeeze pump 1 includes a pump case 5, a rubber pad (hereinafter referred to as “rubber pad”) 6, a pumping tube 7, and a roller unit 9.

  The pump case 5 is formed in a cylindrical shape with both sides closed. The inner diameter of the pump case 5 is 1066 mm in this embodiment. However, about the dimension of the following each part including the internal diameter of the pump case 5, an example is shown and it does not specifically limit.

  The inside of the pump case 5 is hermetically sealed and is decompressed by the vacuum pump 11 of FIG. Inside the pump case 5, a rubber pad 6 is attached to the arc-shaped inner surface 5a.

  The rubber pad 6 functions as a cushioning material and a position fixing material for the pumping tube 7.

  The rubber pad 6 of this embodiment includes a lower pad portion 8a, a middle lower pad portion 8b, a middle upper pad portion 8c, and an upper pad portion 8d that are divided into four parts. The pad portions 8a to 8d are continuously arranged in the circumferential direction in order from the lower side of FIG. 2 on the inner surface 5a of the pump case 5, and are fixed by bonding or the like. Thereby, the rubber pad 6 is an arc-shaped strip that is continuous along the inner surface 5a of the pump case 5 as a whole. In this embodiment, the rubber pad 6 extends along the inner surface 5a of the pump case 5 from the position of about 6 o'clock of the timepiece in FIG. 2 to the position of about 1 o'clock.

  The rubber pad 6 can be formed in a shape in which the pad portions 8a to 8d are integrated. However, as long as the pad portion 8a to 8d is divided into four as in the present embodiment, the rubber pad 6 is partially worn. It is advantageous in that the time and cost for the replacement work can be reduced.

  The rubber pad 6 has an arcuate curved shape in accordance with the arcuate shape as a whole. The surface 6a of the rubber pad 6 is in contact with the intermediate portion 7a of the pumping tube 7, and supports the pumping tube 7 by frictional force. Thereby, the rubber pad 6 functions as a position fixing material for the pumping tube 7.

  The rubber pad 6 provides cushioning properties as a cushioning material for supporting the pumping tube 7 due to its elasticity. Therefore, the rubber pad 6 must retain the hardness and physical properties that retain cushioning properties, and in this embodiment, the JIS-A hardness is set to about 60 degrees to 80 degrees. In the rubber pad 6 of this embodiment, the width W of the pad portions 8a to 8d is about 275 mm, and the wall thickness T of the pad portions 8a to 8d is about 34 mm (see FIG. 4).

  A cooling structure 23 to be described later is adopted for the contact portion between the rubber pad 6 and the pumping tube 7.

  The pumping tube 7 is made of a rubber tube and has elasticity and flexibility. The intermediate portion 7 a of the pumping tube 7 is accommodated inside the pump case 5, and is curved in a U shape along the rubber pad 6 of the pump case 5. Thereby, the curved portion of the intermediate portion 7 a of the pumping tube 7 is in contact with the surface 6 a of the rubber pad 6.

  Both end portions 7 b and 7 c of the pumping tube 7 are drawn out through the openings 5 b and 5 c of the pump case 5, respectively. One end portion 7b of the pumping tube 7 is coupled to the hopper 13 of FIG. 1 to be a suction side of the raw food, and the other end portion 7c is coupled to a discharge destination to be a discharge side. A sealing member 15 ensures sealing performance between the pumping tube 7 and the openings 5 b and 5 c of the pump case 5.

  The outer diameter D of the pumping tube 7 is substantially the same over the entire length, and the inner diameter gradually decreases from the suction side toward the discharge side. That is, the inner diameter d2 on the discharge side is smaller than the inner diameter d1 on the suction side.

  The pumping tube 7 of this embodiment has an inner diameter d2 on the discharge port side of about 102 mm, an outer diameter D of about 148 mm, and a wall thickness of about 23 mm. The central portion 7a of the pumping tube 7 has a central angle of 180 degrees. However, the center angle can be changed according to the specifications of the squeeze pump 1 and is set, for example, between about 120 degrees and 220 degrees.

  A roller unit 9 is disposed on the curved inner side of the intermediate portion 7 a of the pumping tube 7. The roller unit 9 includes a rotor 17, a roller 19, a side guide roller 20, and an inner guide roller 22.

  The rotor 17 is rotatably supported on the shaft center portion of the pump case 5. The rotor 17 is connected to a hydraulic motor (not shown) and is driven to rotate by the driving force. The rotor 17 supports a plurality of rollers 19 at predetermined intervals in the rotation direction. In this embodiment, two rollers 19 are provided every 180 degrees.

  The rotation axis of the roller 19 is rotatably supported by the rotor 17 via the adjustment mechanism 21. The adjustment mechanism 21 makes it possible to adjust the clearance C (see FIG. 5) between the roller 19 and the rubber pad 6 by moving the roller 19 in the protruding and retracting direction with respect to the rotor 17.

  Each roller 19 is provided with a rubber roll 19b on the outer peripheral surface of the core metal 19a. The roller 19 rolls while pressing the pumping tube 7 against the rubber pad 6 from the inside of the curve according to the rotation of the rotor 17, and sequentially crushes the pumping tube 7 with the rubber pad 6. During this crushing, the rubber pad 6 functions as a cushioning material for the pumping tube 7. Accordingly, the rubber pad 6 is provided at least in a range where the pumping tube 7 is pressed.

  In FIG. 2, the roller 19 of this embodiment starts pressing the pumping tube 7 from the position of about 6 o'clock of the watch, rolls along the pumping tube 7 as it is, and gradually presses at the position of about 12 o'clock of the watch. Is released.

  As a result, the squeeze pump 1 can discharge and pressure-feed the raw corn sucked from the one end portion 7b of the pumping tube 7 so as to be squeezed from the other end portion 7c. In the present embodiment, since the inside of the pump case 5 is in a vacuum state, restoration after the pumping tube 7 is crushed can be promoted, and the raw component to be pumped next can be sucked by the pumping tube 7.

  A side guide roller 20 and an inner guide roller 22 are supported between the two rollers 19 in the rotational direction of the rotor 17.

  The side guide roller 20 is supported by the rotor 17 so as to be disposed on the side of the pumping tube 7 in the rotational axis direction of the rotor 17. Thereby, the side guide roller 20 restricts the pumping tube 7 from meandering.

  The inner guide roller 22 has a smaller diameter than the roller 19 and is rotatably supported by the rotor 17 in the same manner as the roller 19. The inner guide roller 22 prevents the pumping tube 7 from separating from the rubber pad 6 when the pumping tube 7 is pressed by the roller 19.

[Cooling structure]
FIG. 3 is an enlarged cross-sectional view of a main part of the squeeze pump 1 of FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG.

  As described above, the cooling structure 23 is employed for the contact portion between the rubber pad 6 and the pumping tube 7 as shown in FIGS.

  At the contact portion between the rubber pad 6 and the pumping tube 7, the pumping tube 7 moves in the axial direction with respect to the rubber pad 6 during operation of the squeeze pump 1, and heat is generated by frictional sliding at this time. Further, at the contact portion, the pumping tube 7 and the rubber pad 6 are compressed by the pressure of the roller 19 to generate heat. The cooling structure 23 of the present embodiment cools against heat generated at such a contact portion, and includes a hole portion 25 provided in the rubber pad 6 and a tank 27 connected to the hole portion 25.

  The hole 25 penetrates the rubber pad 6 in the thickness direction and opens on the surface 6 a of the rubber pad 6 that contacts the pumping tube 7. Therefore, the hole 25 is normally closed with respect to the inside of the pump case 5 by the pumping tube 7. Further, the hole 25 is opened to the inside of the pump case 5 when the pumping tube 7 is bent and separated from the surface 6a of the rubber pad 6 in accordance with the rolling of the roller 19 (see FIG. 5A). That is, the hole 25 is configured to be opened and closed with respect to the inside of the pump case 5 by the bending of the pumping tube according to the rolling of the roller 19. Details of the operation will be described later.

  The formation position of the hole 25 is on the rear side in the rolling direction of the roller 19 with respect to the rolling direction of the roller 19 rather than the most heat generating portion of the contact portion between the rubber pad 6 and the pumping tube 7. In the present embodiment, the portion that generates the most heat is around 12:00 of the timepiece of FIG. 2, and the hole 25 is located near 11:00 of the timepiece behind it. Note that the most heat generating portion varies depending on the central angle of the intermediate portion 7a of the pumping tube 7 and the pumping pressure. In the direction of the rolling axis of the roller 19, a hole portion 25 is located at a substantially central portion in the width direction of the rubber pad 6.

  The cross-sectional shape of the hole 25 is not particularly limited, but can be a circular, elliptical, or polygonal cross section. The vertical cross-sectional shape of the hole 25 can be a constant shape over the entire length, a frustum shape that gradually reduces or expands, or a multistage shape that gradually decreases or expands.

  The hole 25 of the present embodiment will be described in detail later, but the rubber pad 6 that is pressed (compressed) via the pumping tube 7 when the pumping tube 7 is pressed according to the rolling of the roller 19 will be described later. Closed by bending. Further, when the pressing of the rubber pad 6 is released, the hole 25 is opened by the elasticity of the rubber pad 6. In this range, the diameter of the hole 25 is set in relation to the thickness and hardness of the rubber pad 6.

  In the present embodiment, for example, when the thickness of the rubber pad 6 is about 10 mm or more and the hardness of the rubber pad 6 is JIS-A hardness of about 60 degrees to 80 degrees, the diameter of the hole 25 is set to about 2 mm or more. The This is because if the diameter of the hole 25 is less than 2 mm, the hole 25 remains closed due to the permanent deformation of the rubber pad 6, or when the cooling water is sucked as described later, This is because dust may be sucked together and the hole 25 may be closed.

  The diameter of the hole 25 is preferably set to about 10 mm or less. This is because if the diameter of the hole 25 exceeds 10 mm, the sealing area to be closed by the pumping tube 7 is widened, and cooling water may leak even in the low-pressure operation state described later. This is because if it is large, the rubber pad 6 may be damaged from the starting point.

  In this embodiment, the hole 25 having such a configuration is connected to the tank 27 in FIG. 1 through a nozzle 29 provided in the pump case 5 and a pipe 31 connected to the nozzle 29.

  The nozzle 29 is provided integrally with the main body of the pump case 5. The nozzle 29 is formed in a hollow cylindrical shape, and an internal communication hole 29 a communicates concentrically with the hole 25 of the rubber pad 6. The communication hole 29a is formed to have a larger diameter than the hole portion 25 of the rubber pad 6 in the present embodiment, but may have the same diameter as the hole portion 25 or a smaller diameter than the hole portion 25. The nozzle 29 may be provided with a valve (not shown) for flow rate adjustment.

  One end of a hollow pipe 31 such as a steel pipe or a flexible hose is connected to the nozzle 29, and the other end of the pipe 31 is connected to the tank 27 in FIG. 1 located outside the pump case 5. . In the pipe 31, the internal communication hole 31 a communicates with the communication hole 29 a of the nozzle 29 and the inside of the tank 27.

  The tank 27 is mounted on the pump vehicle 3 as holding pump cleaning water, and holds cleaning water inside. In this embodiment, the cleaning water is used as a cooling liquid (cooling water). Therefore, it is not necessary to prepare the cooling tank 27 and water. The water in the tank 27 is tap water that can be pressurized with an electric pump during cleaning. The inside of the tank 27 is in a non-depressurized state that is not sealed with respect to the outside, and is at atmospheric pressure.

  The cooling liquid may be other than water as long as it takes heat of vaporization, and an antifreezing liquid, glycerin, alcohol, or the like can be appropriately used. However, in this case, it is necessary to provide a cooling tank separately.

[Cooling structure operation]
FIG. 5 is a cross-sectional view of the main part showing the cooling operation of the squeeze pump of FIG.

  The cooling structure 23 according to the present embodiment operates when the ready-mixed pump is pumped by the squeeze pump 1. In other words, as described above, the raw container is pumped by pressing the pumping tube 7 from the inside of the curve by the rolling of the roller 19 as shown in FIG. The pumping tube 7 is sequentially crushed between them.

  At this time, the cooling structure 23 of the present embodiment is adapted to reduce the pressure inside the pump case 5 and press the pumping tube 7 as the roller 19 moves from the position shown in FIG. 5B to the position shown in FIG. It operates by utilizing the contact separation with respect to the rubber pad 6.

  Specifically, as shown in FIG. 5A, when the pumping tube 7 is pressed according to the rolling of the roller 19, the drag force in the rolling direction of the roller 19 acting on the pumping tube 7 and The pumping tube 7 returns to the original linear shape on the rear side in the rolling direction with respect to the roller 19 due to the non-average force caused by the pressure feeding.

  By returning to the linear shape, the pumping tube 7 is separated from the surface 6 a of the rubber pad 6, and a local gap S is formed between the pumping tube 7 and the rubber pad 6. The separation operation of the pumping tube 7 can be suppressed to some extent by the inner guide roller 22, but is not completely suppressed.

  Although the separating operation of the pumping tube 7 depends on the elasticity or rigidity of the pumping tube 7, it does not occur when the pressure of the raw concrete is relatively low, and occurs when the pressure of the raw concrete is relatively high.

  For example, in the case of a pumping pressure (discharge pressure) of 1.0 MPa or less during normal low-pressure operation, the pumping tube 7 is small in both the straight extension of the pumping tube 7 by the internal pressure (non-average force) and the drag force by the roller 19. 7 and the rubber pad 6 are always in pressure contact.

  For this reason, as shown in FIG. 2, the hole 25 is closed by the pumping tube 7, and cooling is not performed without the intake of cooling water as described later. However, during low pressure operation, there is little heat generation between the rubber pad 6 and the pumping tube 7, so cooling is not necessary.

  Thus, during low pressure operation that does not require cooling, the intake of cooling water is automatically stopped.

  On the other hand, when the pumping pressure (discharge pressure) is increased to about 1.5 MPa by increasing the number of rotations of the rotor 17 by high-pressure operation, the pumping tube 7 increases in a straight shape and is caused by the action of the non-average force due to the internal pressure. The pumping tube 7 is separated from the rubber pad 6 as shown in FIG. This separation operation becomes more pronounced during high-pressure and high-speed operation. That is, that is, in the state where the sliding heat generation between the rubber pad 6 and the pumping tube 7 during high pressure operation is large, the separation distance between the rubber pad 6 and the pumping tube 7, that is, the gap S becomes large. The expansion of the gap S is based on the fact that the region extending in a straight line of the pumping tube 7 becomes wider and longer as the internal pressure increases, ie, the front side in the rotational direction of the rotor 17, that is, the 11:00 position of the watch in FIG. From the direction of the 12 o'clock position.

  In this embodiment, when the roller 19 rolls to the position of about 12 o'clock of the timepiece in FIG. 2, a gap S begins to be generated between the pumping tube 7 and the rubber pad 6 at the position of about 11 o'clock. The gap S is maximized when the position reaches about 12:30.

  When the gap S is thus formed, the hole 25 of the rubber pad 6 is opened to the inside of the pump case 5. As a result, the inside of the tank 27 communicates with the inside of the pump case 5 via the pipe 31, the nozzle 29, and the hole 25.

  At this time, since the inside of the tank 27 is atmospheric pressure and the inside of the pump case 5 is in a vacuum state, the cooling water in the tank 27 is forcibly and automatically sucked into the pump case 5 side due to the pressure difference between the two. Is done. The sucked cooling water reaches the gap S from the hole 25 and is slightly diffused and ejected to the front side in the rolling direction of the roller 19 with respect to the hole 25. In the present embodiment, the cooling water reaching the gap S is slightly diffused in the direction of 12:00 of the timepiece in FIG. 2 in the jet jet state. This is because the pumping tube 7 separated from the rubber pad 6 gradually comes into contact with the rubber pad 6 again from the rear end side in the rolling direction of the roller 19.

  The cooling water that has reached the gap S comes into contact with the surface 6a of the rubber pad 6 and the outer surface of the pumping tube 7 that are getting hot, or at the moment when the cooling water is ejected into the gap S due to the internal temperature of the pump case 5. Vaporizes due to vacuum distillation effect.

  For example, when the squeeze pump 1 is operated, the degree of vacuum is at least 150 Torr, usually 80 Torr, and the cooling water that has reached the gap S is heated to the surface 6a of the rubber pad 6, the outer surface of the pumping tube 7, or The boiling point is reached at the internal temperature of the pump case 5 of 40 ° C to 70 ° C. FIG. 6 shows the relationship between the degree of vacuum and the boiling point of water.

  The heat of vaporization of the cooling water is 2250 KJ / kg at a boiling point of 100 ° C., and has a cooling capacity much higher than that of air cooling or the like. Therefore, in the cooling structure 23, a large cooling effect is exhibited when the cooling water is slightly ejected from the hole 25 into the gap S. Thus, the rubber pad 6 and the pumping tube 7 around the hole 25 can be rapidly cooled by vaporizing the cooling water.

  The cooling effect of the present embodiment is particularly remarkable between the position of about 11 o'clock and the position of 1 o'clock in FIG. If the squeeze pump 1 is at a higher pressure, the distance that the pumping tube 7 is separated from the rubber pad 6 is larger and the gap S is also larger. Can do.

  The vaporized cooling water is discharged to the outside by the vacuum pump 11, and water droplets or the like do not stay inside the pump case 5.

  After the cooling is performed in this way, when the roller 19 further rolls and passes the 12:30 position of the timepiece of FIG. 2 to reach the 1 o'clock position, the pressing of the pumping tube 7 is released. For this reason, since the internal pressure of the pumping tube 7 temporarily decreases and the drag force by the roller 19 is lost, the pumping tube 7 is brought into contact with the rubber pad 6 again by the elastic force and is brought into pressure contact therewith. Therefore, in the cooling structure 23, the sealing property of the cooling water against the pressing of the pumping tube 7 by the other roller 19 is ensured.

  During the operation of the cooling structure 23, the hole 25 of the rubber pad 6 is opened and closed by the bending of the rubber pad 6 itself, in addition to the opening and closing of the pumping tube 7 due to contact and separation.

  FIG. 7 is an enlarged view of the main part showing the periphery of the hole portion of the rubber pad 6 corresponding to FIG. 4, and shows a state in which the hole portion 25 of the rubber pad 6 is closed by the bending of the rubber pad 6 itself.

  When the pumping tube 7 is pressed according to the rolling of the roller 19, the rubber pad 6 pressed (compressed) via the pumping tube 7 is also bent. The rubber pad in which the hole 25 is bent as shown in FIG. 7 until the roller 19 passes through the position corresponding to the hole 25 (in this embodiment, the position at about 11 o'clock of the timepiece in FIG. 2) due to this bending. 6 is closed by itself. When the roller 19 passes the position corresponding to the hole 25, the compression of the rubber pad 6 around the hole 25 is released as shown in FIG. 5A and the hole 25 is opened by the elasticity of the rubber pad 6. Is done.

For this reason, in the cooling structure 23 of the present embodiment, the operational stability is improved by opening and closing the hole 25 by the rubber pad 6 itself and opening and closing the hole 25 by the contact separation operation of the pumping tube 7.
[Cooling effect]
FIG. 8 is a chart showing the cooling effect. FIG. 8 shows the temperatures of the rubber pad and the pumping tube after continuous operation for 4 hours in the comparative example having no cooling structure and this example.

  As shown in FIG. 8, in the comparative example, when the pumping pressure is 1.5 MPa, the temperature of the rubber pad and the pumping tube reaches 100 ° C., and the sealing pressure of the pumping tube is lowered. In the comparative example, when the pumping pressure was set to 1.7 MPa, the temperature of the rubber pad and the pumping tube became 130 ° C., and the rubber pad and the pumping tube were partially damaged. Further, when the operation was carried out so that the pumping pressure was 2.0 MPa, the temperature of the rubber pad and the pumping tube became 160 ° C., and both the rubber pad and the pumping tube were damaged.

  On the other hand, the temperature of the rubber pad 6 and the pumping tube 7 of the example could be reduced as compared with the comparative example at a pumping pressure higher than 1.0 MPa during normal low-pressure operation.

  In particular, in the embodiment, even when the pumping pressure becomes 2.0 MPa, the temperature of the rubber pad 6 and the pumping tube 7 can be suppressed to 75 ° C., and the decrease in the sealing pressure can be suppressed and stable fluid pumping is possible. Met.

[Effect of one embodiment]
The cooling structure 23 of the squeeze pump 1 according to the present embodiment includes a hole 25 that penetrates the rubber pad 6 and opens on the surface 6 a of the rubber pad 6, holds cooling water outside the pump case 5, and holds the cooling water in the hole 25. The pumping tube 7 is brought into contact with and separated from the surface 6a of the rubber pad 6 by bending according to the rolling of the roller 19, and the hole portion 25 is brought into contact with the pumping tube 7 due to contact and separation. It is opened and closed with respect to the inside.

  Therefore, in this embodiment, when the pumping tube 7 is separated from the rubber pad 6 by using the contact and separation operation of the pumping tube 7 when pressed by the roller 19 and the pressure reduction in the pump case 5, the opening 25 is opened. The water in the tank 27 can be automatically sucked, and the contact portion between the pumping tube 7 and the rubber pad 6 can be cooled by evaporating the cooling water.

  As described above, in this embodiment, the rubber pad 6 is provided with the hole 25 so as to communicate with the tank 27 located outside the pump case 5, without requiring a special device for supplying cooling water or the like. Cooling of the contact portion between the rubber pad 6 and the pumping tube 7 can be realized at low cost.

  Further, since no special equipment for supplying cooling water or the like is necessary, there is no need for failure or inspection and maintenance of such equipment.

  Moreover, since the rubber pad 6 only needs to be provided with the hole 25, cushioning performance can be obtained over the entire surface 6a in contact with the pumping tube 7. As a result, the rubber pad 6 is not locally excessively displaced when the pumping tube 7 is pressed by the roller 19 and is not damaged by repeated such excessive displacement.

  Further, in this embodiment, the cooling water acts only on the portion where the heat generation is greatest after the 11 o'clock position in FIG. 2 and the portion where the pumping tube 7 repeats the separation contact with the rubber pad 6 due to the pressing rolling of the roller 19. Therefore, even if the rubber pad 6 is given lubricity by cooling water (cooling liquid), there is no change in the performance of holding the pumping tube 7 and maintaining the cushioning property as a whole.

  The squeeze pump 1 having such a cooling structure 23 can be stably operated during the continuous high-pressure operation without the seal pressure being lowered in a short time due to the softening action of the rubber pad 6 and the pumping tube 7 due to the high temperature. is there.

  Further, in this embodiment, due to the cooling effect, the rubber pad 6 and the pumping tube 7 can be prevented from being damaged and worn, and can be used for a long time. As a result, there is no problem that pumping is impossible due to a decrease in the seal pressure even during normal low-pressure pumping of the raw control unit due to partial damage of the rubber pad 6 and the pumping tube 7 during temporary high-pressure pumping of the raw control unit that has occurred in the past.

  Moreover, since the cooling water vaporized at the time of cooling can be discharged as humidity or water vapor from the vacuum pump 11 for decompressing the pump case 5, no special drainage mechanism is required, and there is no influence on the environment. .

  The replacement of the pumping tube 7 which is a consumable item is always performed after use for a certain period of time, but the rotation of the roller 19 is fixed and the rotor 17 is rotated to pull out and attach the pumping tube 7. At this time, if there is adhesion (contamination) of a lubricant such as grease on the surface of the roller 19 or the pumping tube 7, the roller 19 will idle, but in this embodiment, there is no such contamination, and the pumping tube 7 Exchange can be performed smoothly.

  Conventionally, the rubber pad may be hardened and lose its elasticity and cushion effect when used at a high temperature and high pressure until it is not worn, and the life of the pumping tube may be shortened. Since the hardening of such a rubber pad is indistinguishable in appearance, the time for repair and replacement has been missed and often caused a problem. In this example, the rubber pad was quickly cooled by accurate cooling. Since 6 does not harden | cure, such a problem can be suppressed.

  In the cooling structure 23 of the present embodiment, the pumping tube 7 is housed in a curved state inside the pump case 5, and the surface 6 a of the rubber pad 6 has a curved shape that supports the curved outer side of the pumping tube 7 by contact.

  Therefore, in this embodiment, the pumping tube 7 can be reliably separated from the surface 6a of the rubber pad 6 by the dragging force in the rolling direction of the roller 19 acting on the pumping tube 7 and the non-average force due to the pressure feeding of the raw concrete. it can. As a result, the contact / separation operation when the pumping tube 7 is pressed by the roller 19 and the cooling using the reduced pressure in the pump case 5 can be reliably performed.

  The pumping tube 7 of the present embodiment maintains contact with the surface of the rubber pad 6 when the pressure of the green container is relatively low, and bends away from the surface of the rubber pad 6 when the pressure is relatively high. .

  Therefore, the cooling water suction is not performed during the low pressure operation or less depending on the operation method of the squeeze pump 1, and can be automatically performed according to the high pressure state during the high pressure operation. For this reason, in the present embodiment, the contact portion between the rubber pad 6 and the pumping tube 7 can be accurately cooled during high pressure operation with a large calorific value that needs to be cooled, and a special for such cooling. Control equipment, driving skills and experience are not required.

  In the present embodiment, the pumping tube 7 is separated from the surface 6 a of the rubber pad 6 at the rear in the rolling direction with respect to the roller 19 to open the hole 25, and the rubber pad 6 has a position corresponding to the hole 25. Until it passes, it is bent by the pressure of the roller 19 through the pumping tube 7 to close the hole 25 and is restored by passing the roller 19 through a position corresponding to the hole 25 to open the hole 25.

  Therefore, until the roller 19 passes through the position corresponding to the hole 25, the hole 25 which is the front in the rolling direction of the roller 19 can be closed by the pumping tube 7 and can be closed by the bending of the rubber pad 6 itself. .

  When the roller 19 passes through a position corresponding to the hole 25, the hole 25 which is the rear in the rolling direction of the roller 19 can be opened by the pumping tube 7 and the restoration of the rubber pad 6 itself.

  As a result, in this embodiment, the stability of the operation of the cooling structure 23 is improved.

As described above, in this embodiment, a special control device or expensive equipment is not used, so that maintenance work is not required, there is little failure, and the cooling structure is inexpensive in the operation of placing the raw control, which is a severe use condition. 23 and the squeeze pump 1 having the same can be realized, which is extremely useful for the user side.
[Modification]
In the cooling structure 23 of this embodiment, as shown by a two-dot chain line in FIG. 1, a pressure reducing valve 33 may be provided on the side of the hole 25 with respect to the tank 27, for example, in the middle of the pipe 31. The pressure reducing valve 33 operates when the inside of the pump case 5 becomes a certain pressure or more or a certain pressure or less. The pressure reducing valve 33 is effective when, for example, the pumping tube 7 is clogged or the like, and the squeeze pump 1 is in a low pressure operation, the pressure of the raw control unit becomes high.

  As another modification, a plurality of hole portions 25 are provided in the longitudinal direction of the rubber pad 6 (the rolling direction of the roller 19) so that cooling can be performed at a plurality of locations between the rubber pad 6 and the pumping tube 7. Also good.

  In this case, the number of the holes 25 is arbitrary, and can be appropriately set in consideration of the amount of heat generated between the rubber pad 6 and the pumping tube 7.

DESCRIPTION OF SYMBOLS 1 Squeeze type pump 5 Pump case 5a Inner surface 6 Rubber pad 6a Surface 7 Pumping tube 19 Roller 23 Cooling structure 25 Hole 27 Tank (cooling liquid supply source)
33 Pressure reducing valve

Claims (5)

A squeezing type that allows fluid to be pumped by supporting a flexible pumping tube so that it can be separated by contact with a rubber pad provided on the inner surface of the pump case whose pressure is reduced. A cooling structure of the pump,
A hole passing through the rubber pad and opening on the surface of the rubber pad;
A coolant supply source that holds the coolant outside the pump case and communicates with the hole;
The pumping tube contacts and separates from the surface of the rubber pad due to bending according to the rolling of the roller;
The hole is opened and closed with respect to the inside of the pump case by contact separation of the pumping tube.
A cooling structure characterized by that. The cooling structure according to claim 1,
The pumping tube is housed in a curved state inside the pump case,
The surface of the rubber pad has a curved shape that supports the curved outer side of the pumping tube by contact.
A cooling structure characterized by that. The cooling structure according to claim 1 or 2,
The pumping tube maintains contact with the surface of the rubber pad when the pumping pressure of the fluid is relatively low, and bends away from the surface of the rubber pad when the pressure is relatively high.
A cooling structure characterized by that. The cooling structure according to any one of claims 1 to 3,
The pumping tube opens away from the surface of the rubber pad behind the roller pad in the rolling direction with respect to the roller,
The rubber pad is bent by the pressure of the roller through the pumping tube until the roller passes through the position corresponding to the hole, and closes the hole, and the roller corresponds to the hole. Pass through to restore and open the hole,
A cooling structure characterized by that. The cooling structure according to any one of claims 1 to 4,
Provided a pressure reducing valve on the hole side with respect to the coolant supply source,
A cooling structure characterized by that.

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