Pulsation damping device

Abstract

To provide a pulsation damping device that can more easily improve pressure resistance performance. [Solution] The pulsation damping device 1 installed in the flow path comprises a pressure introduction unit 2 and an elastic body unit 3. The pressure introduction unit 2 is provided so as to be directly or indirectly connected to the flow path and so as to be connectable to at least an elastic body unit 3A. The elastic body unit 3 is provided so as to be connected to one another by a plurality of elastic body units 3 and has a pressure transmission chamber 9 and an elastic body 10 provided so as to close the primary side of the pressure transmission chamber 9. The pressure transmission chamber 9 is provided so as to be able to contain a pressure transmission medium 11 when each elastic body unit 3 is connected to one another, and the secondary side is closed by the elastic body 10 of the other elastic body units 3.

Description

[Technical Field]

[0001] This invention relates to a pulsation damping device. [Background technology]

[0002] Fluid power systems use fluids to drive mechanical devices. In such systems, to increase energy density, the fluid pressure of the fluid is increased using pumps such as positive displacement pumps. However, positive displacement pumps have the disadvantage of causing pressure pulsations in the fluid, resulting in drastic fluctuations in fluid pressure from the reference pressure. Therefore, fluid power systems require pulsation damping devices to absorb these pulsations and maintain the fluid pressure at the reference pressure.

[0003] Conventionally, some pulsation damping devices utilize the elastic deformation of an elastic body (see, for example, Patent Document 1). Conventional pulsation damping devices have an atmospheric pressure opening, and an elastic body is arranged so as to separate the fluid flow path from the atmospheric pressure opening. The pressure-receiving area of ​​the elastic body on the atmospheric pressure opening side is set to be smaller than the pressure-receiving area on the flow path side.

[0004] When the operating pressure of the fluid rises above the reference pressure, the elastic body deforms so as to enter the atmospheric pressure release section, thereby conserving the increased fluid pressure as elastic energy and reducing the fluid pressure. When the fluid pressure falls below the reference pressure, the deformation returns to its original state, releasing the conserved elastic energy into the fluid, compensating for the reduced fluid pressure. As a result, the pulsation of the fluid can be attenuated. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-133058 [Overview of the project] [Problems that the invention aims to solve]

[0006] In conventional pulsation damping devices, the pressure resistance performance depends on the thickness of the elastic body. Therefore, to improve the pressure resistance performance of a pulsation damping device, it was necessary to change the thickness of the elastic body according to the fluid pressure. As a result, it was necessary to offer a lineup of pulsation damping devices suitable for each fluid pressure, which was very costly and time-consuming.

[0007] Therefore, the objective of the present invention is to provide a pulsation damping device that can more easily improve pressure resistance performance. [Means for solving the problem]

[0008] The present invention relates to a pulsation damping device installed in a flow path, comprising a pressure introduction unit and an elastic body unit, wherein the pressure introduction unit is provided so as to be directly or indirectly connectable to the flow path and so as to be connectable to at least the elastic body unit located on the most primary side, and the elastic body unit comprises a plurality of elastic body units provided so as to be connectable to one another, and has a pressure transmission chamber and an elastic body provided so as to close the primary side of the pressure transmission chamber, wherein the pressure transmission chamber is provided so as to be able to contain a pressure transmission medium and so as to be closed on the secondary side by the elastic body of the other elastic body units when the elastic body units are connected to one another.

[0009] Furthermore, the present invention allows the pressure transmission medium to be in liquid form. Also, the present invention allows the pressure transmission medium to be in solid form. Furthermore, the present invention allows the secondary side of the pressure transmission chamber of the elastic unit located on the most secondary side to be closed by a lid. Furthermore, the present invention allows the flow path to be a flow path for a fluid food product. [Effects of the Invention]

[0010] The present invention provides a pulsation damping device that can more easily improve pressure resistance performance by comprising elastic units that are connected to each other. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view of an embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] This is a bottom view of an elastic body unit according to an embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating the pulsation of a fluid. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described with reference to Figures 1 to 4. The pulsation damping device 1 is installed in a flow path (not shown), for example, a fluid pressure circuit, and is installed to dampen the pressure pulsations of the fluid flowing in the flow path. A pressurized fluid is flowable through the flow path by a pressurizing means such as a positive displacement pump (not shown). The fluid may be a liquid or a gas, but for example, it may be water, an aqueous liquid, or oil.

[0013] Furthermore, the pulsation damping device 1 comprises a pressure introduction unit 2 and an elastic body unit 3. In this embodiment, the pulsation damping device 1 further comprises a cover 4. In the following description, the upstream side of pressure transmission will be referred to as the primary side and the downstream side as the secondary side.

[0014] The pressure introduction unit 2 is provided so as to be directly or indirectly connectable to the flow path and so as to be connectable to at least the most primary elastic body unit 3 (hereinafter referred to as elastic body unit 3A). In this embodiment, it has an introduction hole 5 for introducing the fluid flowing through the flow path into the pulsation damping device 1, and a screw hole 8 is provided on its periphery 6 so as to be screwable with a bolt 7, which will be described later.

[0015] The plurality of elastic body units 3 are provided so as to be connectable to each other, and the elastic body unit 3 includes a pressure transmission chamber 9 and an elastic body 10. The elastic body 10 is provided so as to close the primary side of the pressure transmission chamber 9, and when each elastic body unit 3 is connected to each other, the secondary side of the pressure transmission chamber 9 is closed by the elastic body 10 of another elastic body unit 3, and the pressure transmission chamber 9 is provided so as to be capable of enclosing a pressure transmission medium 11.

[0016] In the present embodiment, in the elastic body unit 3, the elastic body unit 3 located closest to the secondary side (hereinafter referred to as elastic body unit 3B) is closed by the lid body 4, and a peripheral portion 12 of the elastic body unit 3 is provided with a screw hole 13 which is provided penetrating through the peripheral portion 12 and is screw-engageable with a bolt 7 described later. Note that the pressure transmission chamber 9 of the elastic body unit 3B is an air chamber.

[0017] The pressure introduction unit 2 and the elastic body units 3 are connected so that pressure can be transmitted therebetween by a connecting means. In the present embodiment, the connecting means is the bolt 7, and connection is achieved by screw-inserting the bolt 7 into the screw hole 13 and the screw hole 8.

[0018] There is no limitation on the form of the pressure transmission medium 11, for example, gaseous, liquid, or solid form, as long as the pressure received by the elastic body 10 of the elastic body unit 3 located on the primary side can be transmitted to the elastic body 10 of the elastic body unit 3 located on the secondary side, but an incompressible one is preferable. Specifically, the pressure transmission medium 11 can employ a liquid such as water, an aqueous solution, or oil, or a rod formed of rubber or the like. In the present embodiment, water is employed as the pressure transmission medium 11.

[0019] The pulsation attenuating device 1 stacks a plurality of elastic units 3 such that the elastic bodies 10 overlap with one another via the pressure transmitting media 11, which is substantially equivalent to increasing the thickness of the elastic bodies 10 and improves the pressure resistance performance thereof. Therefore, the number of elastic units 3 stacked corresponds to the reference pressure P0 of the flow path. Note that when the reference pressure P0 is lower than the pressure resistance performance of one elastic unit 3, it is also possible not to stack a plurality of elastic units 3.

[0020] The fluid pressure of the fluid in the flow path pulsates between an upper pulsation pressure P H and a lower pulsation pressure P L due to factors such as driving of the pressurizing means (see FIG. 4). When the fluid pressure rises from the reference pressure P0 toward the upper pulsation pressure P H , the elastic body 10 of the elastic unit 3A deforms toward the pressure transmission chamber 9 and presses the pressure transmission medium 11.

[0021] The pressed pressure transmission medium 11 presses the elastic body 10 of the adjacent secondary-side elastic unit 3, and this elastic body 10 also deforms toward the pressure transmission chamber 9. When this process is sequentially repeated toward the secondary side, a part of the fluid pressure is converted into elastic energy and stored in the elastic bodies 10, so that the fluid pressure approaches the reference pressure P0.

[0022] Conversely, when the fluid pressure drops from the reference pressure P0 toward the lower pulsation pressure P L , a restoring force acts on the deformed elastic bodies 10 to restore them to their original shapes, and the elastic energy stored in the elastic bodies 10 is converted into fluid pressure, so that the fluid pressure approaches the reference pressure P0. By repeating this mutual conversion between elastic energy and fluid pressure, the fluid pressure is maintained in the vicinity of the reference pressure P0, and pulsation is attenuated. In a verification test conducted at 3.0 MPa using a triplex plunger pump, the pulsation attenuating device 1 attenuated pulsation to about 1 / 3 regardless of the frequency of the pump (see Table 1).

[0023] [Table 1]

[0024] The damping rate β can be calculated using the following formula.

[0025]

number

[0026]

number

[0027] In the above formula, P Ave η is the average value of the fluid pressure, η is the pulsation rate, η with η is the pulsation rate with a pulsation damping device. without This is the pulsation rate without a pulsation damping device.

[0028] Therefore, in the pulsation damping device 1 of this embodiment, the pressure resistance performance of the pulsation damping device 1 can be easily improved simply by changing the number of elastic body units 3 that are connected to each other. This eliminates the need to line up pulsation damping devices for each fluid pressure, resulting in lower costs and less effort compared to conventional pulsation damping devices.

[0029] Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate without changing the gist of the invention.

[0030] (1) The scope of application of the present invention is not limited to various fluid power systems, but can be applied to various systems that pump fluids using pumps, etc. For example, in conveying systems for fluid foods such as ketchup, sauces, and yogurt, the pressure pulsation of the food during conveyance can be a problem because the food is conveyed using pumps, etc.

[0031] On the other hand, conventional pulsation damping devices are of an integrally formed structure, so disassembly and cleaning of the pulsation damping device is not easy. For this reason, it has been difficult to apply conventional pulsation damping devices to food conveyance systems that require strict hygiene management.

[0032] Meanwhile, the pulsation damping device 1 of the above embodiment is not integrally formed like conventional pulsation damping devices, but is constituted by a plurality of elastic body units 3, so the pulsation damping device 1 can be easily disassembled and cleaned. Accordingly, the pulsation damping device can also be applied to food conveyance systems that require strict hygiene management.

[0033] (2) In the above embodiment, the secondary side of the elastic body unit 3B is closed by the lid body 4, but it is also possible to omit the provision of the lid body 4 and open the secondary side of the elastic body 3B to the atmosphere. Description of Reference Numerals

[0034] 1 Pulsation damping device, 2 Pressure introduction unit, 3 Elastic body unit 4 Lid body, 5 Introduction hole, 6 Peripheral portion 7 Bolt, 8 Screw hole, 9 Pressure transmission chamber 10 Elastic body, 11 Pressure transmission medium, 12 Peripheral portion 13 Screw hole, P0 Reference pressure, P H Upper pulsation pressure P L Lower pulsation pressure

Claims

1. A pulsation damping device installed in a flow path, It comprises a pressure introduction unit and an elastic body unit, The pressure introduction unit is provided so as to be directly or indirectly connectable to the flow path and so as to be connectable to at least the elastic unit located on the most primary side. The elastic body unit is provided with a plurality of such elastic body units connected to one another, and includes a pressure transmission chamber and an elastic body provided to close the primary side of the pressure transmission chamber. The pulsation damping device is characterized in that the pressure transmission chamber is provided such that each elastic body unit is connected to one another, and the secondary side is closed by the elastic body of the other elastic body units, and a pressure transmission medium can be sealed inside.

2. The pulsation damping device according to claim 1, characterized in that the pressure transmission medium is in liquid form.

3. The pulsation damping device according to claim 1, characterized in that the pressure transmission medium is in a solid state.

4. The pulsation damping device according to any one of claims 1 to 3, characterized in that the pressure transmission chamber of the elastic body unit located on the most secondary side is closed on its secondary side by a cover.

5. The pulsation damping device according to any one of claims 1 to 3, characterized in that the flow path is a flow path for a fluid food product.

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