Pump unit and pump device

Abstract

To provide a pump unit and a pump device capable of improving transfer efficiency.SOLUTION: In a pump unit which includes: an outer cylinder; an inner cylinder disposed at an inner peripheral side of the outer cylinder and composed of an elastic body; and end portion members fixed to axial both end portions of the inner cylinder and axial both end portions of the outer cylinder and forming a space between an outer periphery of the inner cylinder and an inner periphery of the outer cylinder as a closed space, and in which the inner cylinder is expanded toward a centripetal direction by supplying a fluid to the closed space, contracted by discharging the fluid from the closed space, and restorable to a free state by bringing the closed space into an atmospheric pressure state, the inner cylinder is constituted to have a shape of which a pathlength along a surface shape at an inner peripheral side is longer than a linear distance between both end portions, in an axial cross-section in the free state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pump unit and a pump device, and more particularly to a pump device that transfers an object by utilizing peristaltic movement. [Background technology]

[0002] Conventionally, there has been known a pump device having an outer cylinder, an inner cylinder provided along the inner peripheral surface of the outer cylinder, and a passage for supplying a pressurizing medium between the inner cylinder and the outer cylinder, whereby both ends of the inner cylinder in the axial direction are held by the outer cylinder, and restraining bodies that extend in the axial direction of the inner cylinder and restrain deformation of the inner cylinder are provided at multiple locations circumferentially at intervals around the inner cylinder, whereby multiple pump units are connected together such that the inner cylinder can expand centripetally by the pressure of the pressurizing medium, and the connected pump units are expanded and contracted in a manner that mimics peristaltic motion, thereby making it possible to transport a transported object using the inner peripheral side of the inner cylinder as a transport path (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-196689 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such a pump unit, when the inner cylinder expands from the contracted state shown in Fig. 10(a) to the state shown in Fig. 10(b), a dead space is created that the inner cylinder does not reach. This dead space does not contribute to the pumping of the transported goods, and affects the improvement of the transport efficiency of the transported goods. SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a pump unit and a pump device that can improve transfer efficiency. [Means for solving the problem]

[0005] A pump unit for solving the above problems includes an outer cylinder and an inner cylinder that is provided on the inner circumferential side of the outer cylinder and is made of an elastic material that can expand and contract, and the pump unit is configured such that when a fluid is supplied into a closed space defined by the inner circumferential surface of the outer cylinder and the outer circumferential surface of the inner cylinder, the inner cylinder is pressed from the entire outer circumferential surface, expanding while stretching in the centripetal direction, and when the supplied fluid is discharged, the inner cylinder is contracted by its elasticity. ,before The inner cylinder has a conical cylindrical portion and flange portions at both ends of the cylindrical portion. , collection In the axial cross section in the free state during compression, Even during contraction The flange extends from one flange portion to the other flange portion in the axial direction at an incline so as to approach the axial direction in order to approximate the shape when expanded, and after passing the other flange portion, turns back radially outward and extends along the axial direction toward one end side, continuing to the inner periphery of the other flange portion, and has a shape in which the path length along the inner periphery surface between both ends is longer than the linear distance between both ends. Tosu It would be good to do so. According to this configuration, the inner cylinder has a path length that follows the inner peripheral surface shape in the axial cross section in a free state rather than the linear distance between both ends, which facilitates centripetal expansion and reduces dead space during expansion, thereby contributing to improved transfer efficiency. The outer cylinder may also be made of a rigid material or an elastic body that is restricted in its axial extension and is capable of expanding radially outward. In addition, the pump device for solving the above problem is configured as follows: or claim 2 A pump device including the pump unit according to claim 1, further comprising a pressure reducing means for forcibly discharging a fluid from the closed space in the pump unit. Steps The pressure reducing means is configured to create a negative pressure in the closed space when the pump unit is contracted. According to this configuration, a large amount of transported material can be taken into the inner cylinder, and the transport efficiency can be improved. The pump device also has a pump section consisting of three or more pump units connected together, and the pump section has the pump unit adjacent to the upstream side of the pump unit that has been made negative pressure by the pressure reducing means and the pump unit adjacent to the downstream side in an expanded state, so that negative pressure can be applied to the inner cylinders of the pump units adjacent to the upstream and downstream sides, and the dead space that occurs in the pump units adjacent to the upstream and downstream sides can be reduced. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 2 is a schematic diagram of a pump device. [Figure 2] FIG. 4 is a diagram illustrating a contracted state of the pump unit according to the embodiment. [Figure 3] 5A and 5B are diagrams illustrating an expanded state of the pump unit according to the embodiment. [Figure 4] FIG. 2 is an external perspective view of the inner cylinder according to the embodiment. [Figure 5] 2A and 2B are an axial plan view and an axial cross-sectional view of an inner cylinder according to the present embodiment. [Figure 6] 10A and 10B are diagrams showing a test environment and results for comparing the transfer rates of the pump unit according to this embodiment and a conventional pump unit. [Figure 7] FIG. 10 is an external perspective view of another embodiment of the inner cylinder. [Figure 8] 10A and 10B are diagrams showing a pump unit according to another embodiment of the inner cylinder. [Figure 9] 10A and 10B are diagrams illustrating the operation of a pump unit according to another embodiment of the inner cylinder. [Figure 10] FIG. 1 is a schematic diagram of a conventional pump unit. [Figure 11] 10A and 10B are diagrams showing another form of the pump unit. [Figure 12] FIG. 10 is a cross-sectional view of another embodiment of the outer cylinder. [Figure 13] 10A and 10B are diagrams illustrating a contracted state of the pump unit when a negative pressure is applied to the fluid chamber. [Figure 14] 10A and 10B are diagrams showing an example of the operation of the pump section actively utilizing the expansion of the pump unit. [Figure 15] 10A and 10B are diagrams showing an example of the operation of the pump section actively utilizing the contraction of the pump unit. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be described in detail below through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention, and include configurations that can be selectively adopted.

[0008] Fig. 1 is a schematic diagram showing one embodiment of a pump device. As shown in Fig. 1, the pump device 1 includes a pump section 8 (pump) that pumps an object to be transferred, and a control section 100 that controls the operation of the pump section 8. The pump section 8 is provided, for example, midway through a pipe provided for transferring the object to be transferred, integrally with the pipe, or the pump section 8 is provided as the pipe itself. The pump section 8 is configured by connecting a plurality of pump units 10 in series, and the operation of each pump unit 10 is individually controlled by the control section 100.

[0009] The control unit 100 includes an air supply means 102 that supplies compressed air as a working fluid, a valve unit 104 that is provided with valves equal to the number of pump units 10, which enable the supply of compressed air from the air supply means 102 to each pump unit 10 and the discharge of the compressed air supplied to the pump units 10, a control unit 106 that individually controls each valve provided in the valve unit 104, and a pipe 108 that enables air to flow between each valve and each pump unit 10. In the following description, compressed air will be used as the working fluid, but the working fluid is not limited to this and may be a liquid, another gas, or the like.

[0010] The control unit 106 includes a CPU as a calculation means, storage means such as ROM and RAM, and input / output means. The storage means stores programs and the like for driving the pump units 10 that constitute the pump section 8, and the CPU executes processing in accordance with the programs stored in the storage means, thereby outputting signals for opening and closing the valves to each valve of the valve unit 104 via the input / output means, thereby causing the plurality of pump units 10 to perform pumping operations that mimic peristaltic motion.

[0011] [About Pump Unit 10] Fig. 2 is an axial plan view and an axial cross-sectional view of the pump unit 10 in a contracted state. Fig. 3 is an axial plan view and an axial cross-sectional view of the pump unit 10 in an expanded state. As shown in Figures 2 and 3, the pump unit 10 comprises an outer cylinder 14, an inner cylinder 12 arranged coaxially on the inner periphery of the outer cylinder 14 to form a double pipe, and a pair of end members 16;16 that close the space formed between the outer periphery of the inner cylinder 12 and the inner periphery of the outer cylinder 14.

[0012] The pump unit 10 is closed by end members 16;16 and is configured to be able to expand the inner tube 12 in the axial direction by supplying compressed air to the space formed between the inner circumference of the outer tube 14 and the outer circumference of the inner tube 12.

[0013] [About the outer tube] The outer cylinder 14 is configured as a rigid cylindrical body. Materials that can be used to configure the outer cylinder 14 include, for example, metal and resin. Note that being rigid means that the outer cylinder does not substantially deform in the axial direction, radial direction, etc., when the pump unit 10 is operating.

[0014] 2 and 3, the outer cylinder 14 has flange portions 14B on both ends of a cylindrical tube portion 14A. The flange portions 14B are formed integrally with the tube portion 14A and are formed in the shape of hollow disks that extend concentrically radially outward at the ends of the tube portion 14A.

[0015] [About the inner tube] 2 and 3, the inner tube 12 includes a cylindrical tube portion 12A and flange portions 12B at both ends of the tube portion 12A. The flange portions 12B are formed integrally with the tube portion 12A and are formed in the shape of a hollow disk that extends concentrically radially outward at the end of the tube portion 12A. A protrusion 13 that protrudes toward the tube portion 12A (axially inward) is formed around the entire circumference at the tip (outer periphery) of the flange portion 12B.

[0016] The inner cylinder 12 is configured as a deformable cylindrical body that is airtight and elastic. The material that can be used to configure the inner cylinder 12 is, for example, rubber such as natural latex rubber or silicone rubber, or an elastic material such as elastomer.

[0018] Fig. 4 shows an external perspective view of the inner cylinder according to this embodiment. Fig. 5(a) is a plan view of the inner cylinder 12 as viewed in the axial direction, Fig. 5(b) is an axial cross-sectional view taken along line A1-A1 in Fig. 5(a), and Fig. 5(c) is an axial cross-sectional view taken along line A2-A2 in Fig. 5(a).

[0019] As shown in Figures 4, 5(a) and 5(b), the inner cylinder 12 is formed so that the cylinder portion 12A has bulging portions 30 that bulge in the axial direction in a free state. The bulging portions 30 are provided at multiple locations (four locations in this embodiment) in the circumferential direction. As defined in JIS B 0026, the free state refers to a state in which only gravity is applied, and no other external force is applied.

[0020] 5(b) is an axial cross-sectional view of the vicinity of the top of the bulging portion 30. As shown in the figure, the bulging portion 30 is formed so as to have a U-shaped recess in the axial direction between the end members 16, 16 and a V-shaped recess in the radial direction, extending along the axial direction. As shown in FIG. 5(a), the formation of the multiple bulging portions 30 in the tubular portion 12A results in multiple recesses 32 that appear to be recessed radially outward from the inner periphery between adjacent bulging portions 30.

[0021] FIG. 3(c) is an axial cross-sectional view of the vicinity of the bottom of the recess 32. As shown in the figure, the recess 32 is formed so as to extend linearly along the axial direction between the end members 16;16.

[0022] In other words, the tubular portion 12A is formed so that, in an axial cross section in the free state, the path length along the inner surface shape near the bottom of the recess 32 is shortest, the path length along the inner surface shape near the top of the bulge 30 is longest, and the shape changes three-dimensionally so that the path length along the inner surface shape gradually becomes shorter from the bulge 30 to the recess 32.

[0023] In other words, the inner cylinder 12 is formed so that, in an axial cross section in a free state, the path length along the surface shape of the inner periphery is longer than the linear distance between both ends. The linear distance between both ends is, for example, the vicinity of the bottom of the recess 32, in other words, the axial distance between the end members 16, 16.

[0024] [About end parts] The end members 16, 16 are arranged on both ends of the inner cylinder 12 and the outer cylinder 14. The end members 16, 16 can be fixed to both ends of the inner cylinder 12 and the outer cylinder 14, and are also used to secure the pump unit 10. comrades It is configured to enable connection of the above.

[0025] The end member 16;16 includes a flange portion 16A and a cylindrical portion 16B. The flange portion 16A is formed in a flat rectangular shape having a hollow portion 20. The hollow portion 20 is provided as a circular hole through which the cylindrical portion 12A of the inner cylinder 12 can pass. The diameter of the hollow portion 20 is preferably set to a dimension such that it fits tightly against the outer peripheral surface of the cylindrical portion 12A of the inner cylinder 12, for example.

[0026] The flange portion 16A has an annular groove 22 recessed into an annular shape on its axially outer end face 16a. The annular groove 22 is formed concentrically with the hollow portion 20, and is adapted to fit over the protrusion 13 at the tip of the flange portion 12B of the inner tube 12. The outer end face 16a of the flange portion 16A is formed such that, when the protrusion 13 of the inner tube 12 is fitted into the annular groove 22, the flange portion 12B of the inner tube 12 protrudes outward beyond the outer end face 16a.

[0027] The inner cylinder 12 is attached to the end member 16 at a predetermined position by fitting the protrusion 13 of the flange portion 12B into the annular groove 22 of the end member 16. The airtightness of the inner cylinder 12 to the end member 16 is achieved by pressing the flange portion 12B of the inner cylinder 12 against the end member 16 when the inner cylinder 12 is connected to an end member of another pump unit 10 via the end member 16 or to a flange provided on an existing pipe.

[0028] The tubular portion 16B is provided so as to protrude cylindrically in the axial direction from the inner end surface 16b of the flange portion 16A. The central axis of the tubular portion 16B is concentric with the hollow portion 20, and the tubular portion 16B is formed integrally with the flange portion 16A. The tubular portion 16B is formed so that its outer diameter is large enough to be inserted into the inner periphery of the outer tube 14 while sliding against it, and its inner diameter is larger than the inner diameter of the hollow portion 20.

[0029] With the tube portion 16B of the end member 16 inserted, the flange portion 14B of the outer tube 14 is fixed to the inner end surface 16b of the flange portion 16A of the end member 16 by fixing means such as bolts (not shown). The outer tube 14 can be made airtight with the end member 16, for example, by interposing a packing or the like between the flange portion 14B of the outer tube 14 and the flange portion 16A of the end member 16.

[0030] As described above, by attaching both ends of the inner tube 12 and the outer tube 14 to the end members 16;16, the space formed between the outer periphery of the inner tube 12 and the inner periphery of the outer tube 14 becomes a closed space, and a fluid chamber V1 in the pump unit 10 is formed.

[0031] One end member 16 has a supply / discharge hole 28 for supplying and discharging fluid to and from the fluid chamber V1. One end of the supply / discharge hole 28 opens to the outer peripheral surface of the flange portion 16A of the end member 16, and the other end opens to the inner end surface 16b of the flange portion 16A, between the inner cylinder 12 and the outer cylinder 14.

[0032] A pipe 108 extending from the control unit 100 can be connected to the opening on the outer peripheral surface of the flange portion 16A that forms the supply and discharge hole 28 to supply fluid to the fluid chamber V1 and discharge fluid from the fluid chamber V1.

[0033] The supply and discharge holes 28 are not limited to being provided in one end member 16, but may also be provided in the other end member 16, so that fluid can be supplied to and discharged from both end members 16, 16 to the fluid chamber V1. The supply and discharge holes 28 are also not limited to being provided in the end member 16, but may be provided in the outer cylinder 14 so that fluid can be supplied to and discharged from the fluid chamber V1, and may be changed as appropriate depending on the configuration of the pump unit 10.

[0034] According to the above configuration, when compressed air is supplied from the control unit 100 to the fluid chamber V1 through the supply and discharge hole 28, the inner cylinder 12 expands in the axial direction as shown in Figures 3(a) and (b), and when the compressed air supplied to the fluid chamber V1 is discharged, the inner cylinder 12 contracts as shown in Figures 2(a) and (b).

[0035] As described above, the inner cylinder 12 has an axially bulged shape in the contracted state (see FIG. 2), and is therefore pressurized in the axial direction by supplying compressed air to the fluid chamber V1. When the inner cylinder 12 is pressurized by the compressed air, the bulging portion 30 expands preferentially in the centripetal direction, and closes the space on the inner circumferential side of the inner cylinder 12, as shown in FIGS. 3(a) and 3(b). In other words, the inner tube 12 is formed so that the bulging portion 30 when contracted is similar to the expanded state, and as shown in Figure 10(b), the dead space can be made smaller than when the inner tube in a conventional pump unit is expanded.

[0036] FIG. 6(a) is a diagram showing the test environment for the comparative test of transfer rates, and FIG. 6(b) is a diagram showing the test results. In order to verify the effect of the pump unit 10 according to this embodiment, a transfer rate test was conducted on the pump unit alone in the test environment shown in Fig. 5. In the transfer rate test, the inner cylinder having the shape described in the above embodiment was compared with a conventional cylindrical inner cylinder. Test methods and conditions 1. With the pump contracted, insert the test cargo (dummy feces) so that it fills the inside. 2. Apply compressed air (70kpa). 3. Remove the test load that was removed from the pump with compressed air applied. 4. Measure the mass of the test load displaced from the pump and calculate the transfer rate. The transfer rate is calculated as follows: (removed test items / added test items) x 100 As a result, as shown in FIG. 6(b), the pump unit 10 configured with the inner cylinder 12 of this embodiment had a higher transfer rate than the conventional cylindrical inner cylinder.

[0037] Therefore, as shown in FIG. 1, it is clear that the conveying efficiency can be improved by connecting multiple pump units 10 according to the above embodiment to form a pump section 8 and controlling the expansion and contraction of each pump unit 10 by a control section 100 so as to mimic peristaltic movement.

[0038] FIG. 7 is a perspective view of another embodiment of the pump unit 10, and FIG. 8 is an axial plan view and an axial cross-sectional view thereof. The shape of the inner cylinder 12 for reducing the dead space during inflation is not limited to the above embodiment. For example, as shown in Figures 7 and 8, the inner cylinder 12 according to this embodiment may be formed so that a part of it is exposed in the axial direction. ,circle The cylindrical portion 12A has a conical shape, and flanges 12B at both ends of the cylindrical portion 12A. The flanges 12B are formed integrally with the cylindrical portion 12A and are formed as flat rings that extend concentrically radially outward at the ends of the cylindrical portion 12A. A protrusion 13 that protrudes toward the cylindrical portion 12A (axially inward) is formed around the entire periphery of the tip (outer periphery) of the flanges 12B.

[0039] The tubular portion 12A extends from one flange portion 12B toward the other flange portion 12B in the axial direction, inclining toward the axial direction, and after passing the other flange portion 12B, turns back radially outward, extending toward one end along the axial direction and continuing to the inner circumference of the other flat, annular flange portion 12B. As a result, the inner cylinder 12 is formed with a protruding portion 18 that protrudes from the flange portion 12B and is exposed to the outside.

[0040] 9(a), the pump units 10 according to this embodiment are connected with the protruding portion 18 facing downstream in the transfer direction. This connection allows the protruding portion 18 of the adjacent pump unit 10 on the upstream side to enter the inner circumferential side of the inner cylinder 12 of the adjacent pump unit 10 on the downstream side.

[0041] 9(b), for example, by expanding the upstream pump unit 10, the fluid is pushed from this pump unit 10 to the adjacent downstream pump unit 10. If the adjacent downstream pump unit 10 is expanded while the upstream pump unit 10 remains in an expanded state, the dead space formed when the downstream pump unit 10 expands is occupied by the upstream pump unit 10 in an expanded state, thereby improving the transport efficiency.

[0042] As described above, in forming the pump unit 10, the inner tube 12 may be configured to have, for example, a bulge that expands in the centripetal direction in the free state, or a protrusion that protrudes in the axial direction beyond one of the end members 16, so that the path length along the inner surface shape in the axial cross section in the free state is longer than the straight-line distance between both ends, thereby contributing to improved conveying efficiency.

[0043] That is, the inner cylinder 12 may have any shape as long as it can obtain a path length along the inner peripheral surface shape that is longer than the linear distance between both ends in an axial cross section in a free state. A shape that can obtain a path length along the inner peripheral surface shape that is longer than the linear distance between both ends in an axial cross section in a free state means that the tubular portion 12A of the inner cylinder 12 has a larger surface area than the surface area of ​​the inner peripheral surface when the tubular portion 12A is a conventional cylindrical shape. Therefore, if the wall thickness and material of the inner cylinder 12 of the present embodiment are the same as those of the conventional embodiment, it is clear that it can be expanded to a greater extent than the conventional embodiment.

[0044] The shape of the inner cylinder, which makes the path length along the surface shape of the inner circumference longer than the linear distance between both ends in the axial cross section in the free state, is not limited to being configured to have a bulging portion that expands in the centripetal direction in the free state, or to have a protruding portion that protrudes in the axial direction beyond one end member 16. By previously forming the cylindrical portion 12A (between the end members 16, 16) of the inner cylinder 12, which serves as the conveying path, so that the surface area on the inner circumference side is large, the dead space when the pump unit 10 is expanded can be reduced.

[0045] FIG. 11 is an axial cross-sectional view and a radial cross-sectional view of another embodiment of the pump unit. FIG. 12 is an axial cross-sectional view of an outer cylinder made of an elastic body. In the above embodiment, the outer cylinder 14 is described as being rigid and substantially non-shrinkable, but is not limited to this. The outer cylinder 14 may be made of the same material as the inner cylinder 12 or an elastic body.

[0046] Hereinafter, the pump unit according to this embodiment will be referred to as pump unit 10', and the outer cylinder will be referred to as outer cylinder 14'. The inner cylinder 12 and the end members 16, 16, excluding the outer cylinder 14', are as described in the above embodiment. The outer cylinder 14' according to this embodiment is configured as a cylinder made of an elastic body. The outer cylinder 14' is configured to include, for example, an elastic material and a fibrous material.

[0047] 12, outer tube 14′ includes, for example, elastic material 15A and a plurality of fibers 15B contained in elastic material 15A in a radial cross section. Elastic material 15A can be made of a material that is stretchable while maintaining airtightness, such as rubber, elastomer, or the like, such as natural latex rubber or silicone rubber.

[0048] The fibers 15B are arranged within the elastic material 15A so as to form, for example, a layered fiber group. The fibers 15B are provided as a high-speed means for restraining the axial extension of the outer tube 14' and are arranged to extend along the axial direction of the outer tube 14'. For example, the fibers 15B may have a length that extends continuously from one end of the outer tube 14' to the other end. Alternatively, the length of the fibers 15B is not limited to a continuous length from one end to the other end, and multiple fibers shorter than the axial length of the outer tube 14' may be distributed so as to overlap each other along the axial direction and reach from one end to the other end. The fibers 15B do not necessarily have to be contained in layers in the outer tube 14', but may be dispersed and embedded in the elastic material.

[0049] The material for the fibers 15B is preferably a highly elastic fiber that exhibits minimal axial expansion and contraction. For example, stretchable fibers such as aramid fiber, carbon fiber, glass fiber, nylon, polyamide fiber, polyolefin fiber, and metal fiber can be appropriately selected and used. The adhesiveness of the fibers can be sufficiently improved by applying an appropriate primer treatment or surface oxidation treatment, but it is preferable to select the material based on its adhesiveness to the elastic material.

[0050] The fiber material can be in any form, such as filament, yarn (spun yarn or filament yarn), or strand. It is also possible to use untwisted fibers, which are bundled without twisting, or fibers made by twisting multiple fibers. Depending on the type of fiber, two or more fibers of different materials or different forms may be combined.

[0051] It should be noted that the configuration is not limited to the fibers 15B as long as it can restrain the axial extension of the outer tube 14'. For example, instead of the fibers 15B, a rib extending in the axial direction may be integrally formed from the elastic material that constitutes the outer tube 14' to restrain the axial extension of the outer tube 14'.

[0052] [Attaching the outer tube to the end member] The outer cylinder 14' made of an elastic material is fixed to the end member 16;16 as follows: The inner periphery of the outer cylinder 14' is inserted into the outer periphery of the cylindrical portion 16B provided on the end member 16 in a tight fit state. Next, the end side of the outer cylinder 14' is fixed to the cylindrical portion 16B of the outer cylinder 14' in an airtight manner using fixing means composed of, for example, a crimping intermediate member 24 and a crimping member 26.

[0053] The crimped intermediate member 24 is formed as an annular member that can be inserted onto the outer periphery of the outer cylinder 14' in a state where it is inserted into the cylindrical portion 16B of the end member 16. The inner periphery of the crimped intermediate member 24 is formed as a cylindrical surface, and the inner diameter is set so as to provide, for example, an interference fit with the outer periphery of the outer cylinder 14'.

[0054] The outer peripheral side of the crimped intermediate member 24 is formed as a conical surface (tapered surface) whose thickness gradually increases relative to the inner peripheral surface. The crimped intermediate member 24 is disposed on the outer periphery of the outer cylinder 14' so that the thicker side is pressed against the end member 16.

[0055] The crimping member 26 is formed as an annular member that can be fitted from the outer peripheral side to the crimping intermediate member 24 that is arranged on the outer periphery of the outer cylinder 14. The crimping member 26 has an inner peripheral side that is formed as a conical surface (tapered surface) and is configured to come into surface contact with the conical surface of the crimping intermediate member 24.

[0056] The crimping member 26 is fixed to the inner end surface 16b of the end member 16 by fastening means such as bolts (not shown) with the inner conical surface of the crimping intermediate member 24 in contact with the conical surface of the crimping intermediate member 24. As a result, the crimping intermediate member 24 is pressed against the outer tube 14', and the outer tube 14 is fixed to the cylindrical portion 16B of the end member 16 in an airtight state.

[0057] As described above, by attaching the end members 16;16 to the ends of the inner tube 12 and the outer tube 14', the space formed between the outer circumference of the inner tube 12 and the inner circumference of the outer tube 14' becomes a closed space, forming the fluid chamber V1 in the pump unit 10'.

[0058] When compressed air is supplied to the fluid chamber V1 through the supply / discharge hole 28, the pump unit 10' expands, as shown in Figure 11(b), such that the inner cylinder 12 expands radially inward (centripetal direction) and the outer cylinder 14' expands radially outward. The outer cylinder 14' expands radially outward because the fibers contained within the outer cylinder 14' restrict axial extension of the outer cylinder 14'. As a result, the pump unit 10' expands radially outward and contracts axially.

[0059] 11(a) by discharging the compressed air supplied to the fluid chamber V1. (b) As shown in Fig. 1, the diaphragm contracts radially and expands axially.

[0060] The pump unit 10' has an outer tube 14' made of an elastic material, which contracts in the axial direction when expanded, thereby eliminating dead space more effectively than when the outer tube 14 is made of a rigid body as described in the above embodiment.

[0061] When the outer cylinder 14' in the pump unit 10' is made of an elastic material, the elastic modulus of the outer cylinder 14' should be set taking into consideration the ease of expansion of the inner cylinder 12 in the centripetal direction. Preferably, the elastic modulus of the outer cylinder 14' should be set to be greater than the elastic modulus of the inner cylinder 12. By making the elastic modulus of the outer cylinder 14' greater than the elastic modulus of the inner cylinder 12, the expansion of the inner cylinder 12 is completed first, followed by the expansion of the outer cylinder 14'. As a result, the inner cylinder 12 contracts in the axial direction while in an expanded state, thereby reducing dead space and, as a result, improving the transfer efficiency of the pump device.

[0062] As described above, in a free state before compressed air is supplied to the fluid chamber V1, the inner cylinder 12 is formed so that, in the axial cross section during contraction, the path length along the inner circumferential surface between both ends is longer than the linear distance between the ends. This results in an apparent narrowing of the transfer path compared to conventional cylindrical inner cylinders. The inner cylinder 12 is deformable when the fluid chamber V1 is open to the atmosphere. Considering that the material being transferred reaches the pump section 8 due to its fluidity, the inner cylinder 12, which serves as the transfer path, is elastic and expandable, so the inflow of the material is not substantially impeded. Therefore, the "narrowing of the transfer path" can be considered "apparent."

[0063] On the other hand, considering that the inner circumferential side of the inner cylinder 12 is a transfer path, it goes without saying that even in the contracted state, it is preferable for the inner cylinder to be cylindrical as in the past, or wider than that. In such a case, the pump device 1 shown in FIG. 1 may be configured to include a pressure reducing means such as a negative pressure pump. Furthermore, when contracting the pump unit 10, the pressure reducing means may be used to contract the fluid chamber V1, or the fluid chamber V1 may be opened to the atmosphere, the inner cylinder 12 may be contracted in a free state, and then the pressure reducing means may be used to forcibly discharge further air from the fluid chamber V1 to create a negative pressure in the fluid chamber V1. Note that the phrase "after contraction" simply indicates the chronological order of the operation and does not necessarily mean a temporary stop in the contraction operation, but may also mean continuous contraction as a series of operations.

[0064] When the fluid chamber V1 of the pump unit 10 is made negative pressure, as shown in Figure 13, the bulge portion 30 of the inner tube 12 is preferentially deformed radially outward, and the peak of the bulge portion 30 protruding in the centripetal direction is folded back so that it becomes a valley recessed radially outward. That is, Pump Unit 10When the fluid chamber V1 is made negative pressure, the bulging portion 30 of the inner cylinder 12 is deformed as if it were turned inside out, and when the inner cylinder 12 contracts in a free state, the transfer path can be widened more than when the inner cylinder is cylindrical as in the conventional case. As a result, a large amount of material can be taken in on the inner circumferential side of the inner cylinder 12, improving transfer efficiency.

[0065] In the above embodiment, the expansion of the inner cylinder 12 is described as reducing the dead space in the operation of a single pump unit, but this is not limiting. For example, the dead space can also be reduced by utilizing the conveying operation when pump units are connected. In this case, it is preferable to configure the pump section 8 by connecting at least three or more pump units 10.

[0066] Fig. 14 is a diagram showing an example of the operation of the pump section 8 when the expansion of the pump units 10 is actively used to transfer the material to be transported. Fig. 15 is a diagram showing an example of the operation of the pump section 8 when the contraction of the pump units 10 is actively used to transfer the material to be transported. In the following explanation, the operation of the pump section 8 will be described assuming that the pump section 8 is configured by connecting three pump units 10 as shown in Figs. 14 and 15. In addition, in order to identify each pump unit 10, they are represented as pump units 10A, 10B, and 10C from the upstream side in the transport direction.

[0067] First, as shown in FIG. 14, the operation of the pump section 8 when the expansion of the pump unit 10 is actively utilized to transport the transported object will be described. 14(a), the pump section 8 is in an initial state in which, for example, all of the pump units 10A to 10C are contracted. At this time, the transported object flows into the pump units 10A to 10C due to its fluidity and its own weight. 14(b), pump unit 10A is expanded, and pump units 10B and 10C are maintained in a contracted state. As a result, the material being conveyed in pump unit 10A is pressurized by inner tube 12 of pump unit 10A, and most of the material moves toward pump unit 10B. Although some of the material being conveyed pressurized by inner tube 12 of pump unit 10A attempts to be pushed toward the upstream side of pump unit 10A, the weight of the material that has reached pump unit 10A acts as a barrier, causing the material to move toward pump unit 10B. 14(c), pump unit 10B is expanded while pump unit 10A is maintained in the expanded state and pump unit 10C is maintained in the contracted state. As a result, the pump unit 10A acts as a wall to pressurize the inner cylinder 12 of pump unit 10B, and the material being transported in pump unit 10B moves to pump unit 10C, excluding the dead space generated between pump units 10A and 10B. 14(d), while maintaining the expanded state of pump unit 10B, pump unit 10A is contracted and pump unit 10C is expanded. As a result, the material being transported in pump unit 10C moves out of pump unit 10C, except for the dead space created between pump units 10B and 10C, as pump unit 10B acts as a wall to pressurize inner cylinder 12 of pump unit 10C. Furthermore, as pump unit 10A contracts, the material being transported from the upstream side is taken into inner cylinder 12 of pump unit 10A. 14(e), while maintaining the contracted state of pump unit 10A and the expanded state of pump unit 10C, pump unit 10B is contracted, causing the material to flow further from the upstream side into inner cylinder 12 of pump unit 10A, and the material in pump unit 10A is taken into inner cylinder 12 of pump unit 10B. Next, while maintaining the contracted states of pump units 10A and 10B, pump unit 10C is contracted, resulting in the state shown in Fig. 14(a), in which the transported object moves from upstream to pump unit 10A, from pump unit 10A to pump unit 10B, and from pump unit 10B to pump unit 10C. In other words, the objects to be conveyed are pressurized by the pump unit 8 and conveyed downstream, with the cycle consisting of FIGS. 14(a) to 14(e).

[0068] On the other hand, as shown in Fig. 15, the operation of the pump section 8 when the contraction of the pump unit 10 is actively used to transport the transported object will be described. In this case, the pump device 1 shown in Fig. 1 is configured to include a pressure reducing means. As shown in FIG. 15(a), in the pump section 8, for example, the pump units 10A and 10B are in an expanded state, and the pump unit 10C is in an over-contracted state (see FIG. 13) by the pressure reducing means. 15(b), while maintaining the expanded state of pump unit 10B, pump unit 10A is put into the over-contracted state and pump unit 10C is put into the expanded state. By putting pump unit 10A into the over-contracted state, the inner peripheral side of inner cylinder 12 of pump unit 10A becomes negative pressure, and the transported object is drawn into pump unit 10A. Next, as shown in FIG. 15(c), while the pump unit 10C is maintained in an expanded state, the pump unit 10A is expanded and the pump unit 10B is over-contracted. As a result, the material being conveyed is pressurized by the expansion of the inner cylinder 12 of pump unit 10A, and is drawn into pump unit 10B by the negative pressure of contracting pump unit 10B. Because pump unit 10B is over-contracted by the pressure reducing means, the inner circumferential side of inner cylinder 12 of pump unit 10B after pump unit 10A expands is under negative pressure. This negative pressure acts as a force that draws inner cylinder 12 of expanded pump unit 10A or pump unit 10C toward pump unit 10B, thereby reducing the dead space formed on the pump unit 10B side of pump units 10A and 10C and contributing to reducing the material remaining in expanded pump unit 10A or pump unit 10C.

[0069] The number of pump units 10 constituting the pump section 8 is not limited to three and may be more than three. As described above, when the pump units 10 are actively contracted using the pressure reducing means to transfer the material, the pump units 10 upstream and downstream of the pump unit 10 that is over-contracted by the pressure reducing means are kept in an expanded state, thereby reducing the dead space of the expanded upstream and downstream pump units 10 and reducing the material remaining in the expanded upstream and downstream pump units 10. Therefore, the number of pump units 10 contracted by the pressure reducing means between the expanded upstream and downstream pump units 10 may be any number.

[0070] Furthermore, when the outer tube 14 of the pump unit 10' is made of an elastic material to create negative pressure in the fluid chamber V1, it is preferable to set the elastic modulus of the outer tube 14 of the pump unit 10' so that the effect of the negative pressure in the fluid chamber V1 is smaller than that of the inner tube 12.

[0071] As described above, the pump unit 10 can reduce the dead space during expansion by configuring the inner cylinder to have a bulging portion that expands centripetally in the free state or a protruding portion that protrudes axially beyond one end member so that the path length along the inner circumferential surface between both ends in an axial cross section in the contracted free state is longer than the linear distance between the ends. Furthermore, when the pump unit 10 has such an inner cylinder, by creating a negative pressure in the fluid chamber V1 using a pressure reducing means, the inner cylinder 12 expands radially outward more than in the free state, thereby applying a larger negative pressure to the space inside the inner cylinder 12, which is the transfer path for the transported object, compared to when the centripetal-expanded inner cylinder 12 is contracted to the free state. To utilize this negative pressure, the pump section 8 is configured by connecting three or more pump units 10, and the pump units 10 (the number is not limited) adjacent to the upstream and downstream sides of the pump unit 10 whose fluid chamber V1 is made negative pressure by the pressure reducing means are expanded, and the fluid chamber V1 is made negative pressure by the pressure reducing means of the pump units 10 located between them. This reduces the dead space of the pump units 10 adjacent to the upstream and downstream sides in the expanded state, reducing the amount of transported material contained in the dead space and improving transfer efficiency. [Explanation of symbols]

[0072] 1 pump device, 8 pump section, 10 pump unit, 12 inner cylinder, 14 outer cylinder, 16 end member, 100 control section.

Claims

1. An outer tube and an inner tube provided on the inner circumferential side of the outer tube and made of an elastic material that can be stretched and contracted, A pump unit configured to supply a fluid into a closed space defined by the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder, thereby pressing the inner cylinder from the entire outer peripheral surface, causing the inner cylinder to expand while stretching in a centripetal direction, and to contract while shrinking the inner cylinder by its elasticity when the supplied fluid is discharged, The inner cylinder is A conical cylindrical portion and flange portions at both ends of the cylindrical portion are provided. The cylindrical portion has, in an axial cross section in a free state during contraction, In order to approximate the shape when expanded even when contracted, the flange extends in the axial direction from one flange portion to the other flange portion at an incline so as to approach the axial direction, and after passing the other flange portion, turns back radially outward, extends along the axial direction toward one end side, and is formed so as to be continuous with the inner periphery of the other flange portion, A pump unit characterized in that the length of a path along an inner peripheral surface between both end portions is longer than the linear distance between the two end portions.

2. 2. The pump unit according to claim 1, wherein the outer cylinder is made of a rigid material or an elastic material that is restricted in its axial extension and is capable of expanding radially outward.

3. A pump device including the pump unit according to claim 1 or 2, a pressure reducing means for forcibly discharging fluid from the closed space in the pump unit; The pump device is characterized in that the pressure reducing means creates a negative pressure in the closed space when the pump unit is contracted.

4. a pump section formed by connecting three or more of the pump units; 4. The pump device according to claim 3, wherein the pump unit adjacent to the upstream side of the pump unit that has been brought to a negative pressure by the pressure reducing means and the pump unit adjacent to the downstream side of the pump unit are in an expanded state.

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