Suction Strainer
The suction strainer addresses horizontal installation issues by using baffle plates and a cover to contain and discharge air bubbles, ensuring smooth fluid flow and preventing pump malfunctions.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- YAMASHIN FILTER CORP
- Filing Date
- 2022-03-31
- Publication Date
- 2026-07-03
AI Technical Summary
In horizontal installations of filtration systems, air bubbles attached to the lower half of the filtration section cannot float upward, leading to potential pump malfunctions and damage due to air ingress.
A suction strainer with a cylindrical filtration section and baffle plates positioned above and below the central axis, along with a cover and air vent system, to prevent air bubbles from flowing into the pump by guiding them into a reservoir and releasing them externally.
Prevents air bubbles from exiting the suction strainer, thereby avoiding pump malfunctions and damage, while allowing efficient fluid flow and bubble discharge.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a suction strainer.
Background Art
[0002] Patent Document 1 discloses a suction filter in which a cover is provided on the upper end surface of a cylindrical first filtration part so as to cover the entire upper side of the first filtration part, and a valve is provided below the cover and in the hollow part of the first filtration part. The valve can be switched between a closed state in which a first valve body movable along a rod-shaped member closes the hole in the cover and an open state in which the hole is not closed.
Prior Art Document
Patent Document
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the invention described in Patent Document 1, since the axis of the cylindrical filtration part is along the vertical direction, that is, a so-called vertical installation, the air bubbles attached to the filtration part float inside the oil stored in the tank, and the air bubbles are discharged outside the suction filter through the valve. However, due to restrictions on the installation position, in recent years, the so-called horizontal installation in which the filtration part is provided along the horizontal direction has been increasing. In such a case, it is more difficult for air bubbles to float compared to the case of vertical installation.
[0005] Figure 15 schematically illustrates the behavior of bubbles attached to the filtration section 150, with (A) being an example of a vertical orientation and (B) being an example of a horizontal orientation. In the vertical orientation, bubbles attached to the filtration section 150 float upward along the filtration section 150 (see arrow in Figure 15(A)). In contrast, in the horizontal orientation, bubbles attached to the upper half of the filtration section 150 can float upward (see arrow in Figure 15(B)), but bubbles attached to the lower half of the filtration section 150 are blocked by the filtration section 150 and cannot float upward. As a result, bubbles attached to the lower half of the filtration section 150 pass through the filtration section 150, which may cause the pump to malfunction by sucking in air, or cause parts to be damaged by bubbles bursting in the hydraulic circuit.
[0006] This invention has been made in view of these circumstances, and aims to provide a suction strainer that can prevent the outflow of air bubbles when the filtration section is provided along the horizontal direction. [Means for solving the problem]
[0007] To solve the above problems, the suction strainer according to the present invention is, for example, a suction strainer provided in a tank in which liquid is stored, comprising: a cylindrical filtration section having a cylindrical pleated filter material formed by bending a thin plate into a pleated shape; a cylindrical mounting section provided on the side surface of the tank, to which one end of the filtration section is provided; a plate covering the end of the filtration section on the side where the mounting section is not provided; and a baffle plate having at least one of a first baffle plate provided inside the pleated filter material and a second baffle plate provided outside the pleated filter material, wherein the filtration section is provided along the horizontal direction, the filtration section and the plate are provided inside the tank, at least a portion of the first baffle plate is positioned above the central axis of the filtration section, and at least a portion of the second baffle plate is positioned below the central axis.
[0008] According to the suction strainer of the present invention, the filtration section, which is provided horizontally, and the plate covering one end of the filtration section are provided inside a tank in which liquid is stored. The suction strainer also has at least one of a first baffle plate provided inside the pleated filter material of the filtration section and a second baffle plate provided outside the pleated filter material, wherein at least a portion of the first baffle plate is positioned above the central axis of the filtration section, and at least a portion of the second baffle plate is positioned below the central axis of the filtration section. This prevents the outflow of air bubbles from the suction strainer. As a result, the inflow of air bubbles into a pump provided downstream of the suction strainer is prevented.
[0009] The first baffle plate has a cylindrical air reservoir at one end, which is provided at the mounting portion. The radius of the air reservoir may be larger on the mounting portion side and gradually decrease as it approaches the plate. This biases the air bubbles that come into contact with the air reservoir upward, making it difficult for the bubbles to flow into the hollow portion of the mounting portion. Furthermore, by making the air reservoir cylindrical, more air bubbles can be blocked by the air reservoir.
[0010] The first baffle plate, when cut by a first plane perpendicular to the central axis, has a circular arc cross-sectional shape and has an air reservoir that intersects with the line segment connecting the upper end of the filtration section and the central axis. One end of the air reservoir is provided on the mounting section, and the radius of the air reservoir may be larger on the mounting section side and gradually decrease as it approaches the plate. This biases the air bubbles that come into contact with the air reservoir in an upward force, making it difficult for the air bubbles to flow into the hollow part of the mounting section.
[0011] The first baffle plate has a cross-sectional shape that is arc-shaped when cut by a first plane perpendicular to the central axis, and has an upper cover provided at a position that intersects with the line segment connecting the upper end of the filtration section and the central axis, and the upper cover may be provided on the plate side of the air reservoir section. This allows more bubbles to be accumulated in the space above the air reservoir section, and as a result, the amount of bubbles flowing out from the suction strainer can be further reduced.
[0012] The second baffle plate may be a lower cover provided at a position where it intersects with a line segment connecting the lower end of the filtration section and the central axis, and has a cross-sectional shape that is arc-shaped when cut by a first plane perpendicular to the central axis. This prevents air bubbles from flowing into the hollow part of the filtration section.
[0013] The pleated filter material comprises a cylindrical first pleated filter material and a cylindrical second pleated filter material provided inside the first pleated filter material. The first baffle plate may be provided inside the second pleated filter material, and the second baffle plate may be provided outside the second pleated filter material. This prevents the outflow of air bubbles from the suction strainer even when there are two pleated filter materials.
[0014] The mounting portion is provided with an air vent hole that connects the hollow portion of the mounting portion to the external space of the mounting portion, and a float may be provided in the air vent hole so as to be movable between a position that closes the air vent hole and a position that opens the air vent hole. This allows air bubbles to be discharged through the air vent hole.
[0015] The device comprises a cylindrical cover, one end of which is provided on the mounting portion and the other end on the plate, the cover being provided horizontally, and a band-shaped area along the horizontal direction located near the lower end of the cover may have multiple holes. This reduces the number of air bubbles that collide with the filtration portion. [Effects of the Invention]
[0016] According to the present invention, it is possible to prevent the outflow of air bubbles from a suction strainer in which the filtration section is provided along the horizontal direction. [Brief explanation of the drawing]
[0017] [Figure 1] This diagram shows a schematic of the hydraulic circuit 110, including the suction strainer 1. [Figure 2] It is a diagram showing an overview of the suction strainer 1 and the tank 100. [Figure 3] It is a cross-sectional view showing an overview of the suction strainer 1. [Figure 4] It is a diagram showing an overview of the suction strainer 1A. [Figure 5] It is a cross-sectional view showing an overview of the suction strainer 2. [Figure 6] It is a diagram showing an overview of the suction strainer 3, (A) is a cross-sectional view, and (B) is a cross-sectional view of the suction strainer 3 cut along the A-A plane. [Figure 7] It is a diagram showing an overview of the suction strainer 3A, (A) is a cross-sectional view, and (B) is a cross-sectional view of the suction strainer 3A cut along the B-B plane. [Figure 8] It is a cross-sectional view showing an overview of the suction strainer 4. [Figure 9] It is a diagram showing an overview of the suction strainer 5, (A) is a cross-sectional view, and (B) is a perspective view. [Figure 10] It is a cross-sectional view showing an overview when the suction strainer 5 is cut along the C-C cross-section. [Figure 11] It is a diagram showing an overview of the suction strainer 5A, (A) is a perspective view, and (B) is a cross-sectional view when cut along a plane perpendicular to the central axis ax. [Figure 12] It is a diagram showing an overview of the suction strainer 5B, (A) is a perspective view, and (B) is a cross-sectional view when cut along a plane perpendicular to the central axis ax. [Figure 13] It is a cross-sectional view showing an overview of the suction strainer 6. [Figure 14] It is a cross-sectional view showing an overview of the suction strainer 7. [Figure 15] It is a diagram schematically showing the behavior of bubbles adhering to the filtration section, (A) is an example of vertical placement, and (B) is an example of horizontal placement.
Embodiments for Carrying Out the Invention
[0018] Embodiments of the present invention will be described in detail below with reference to the drawings. <First Embodiment> Figure 1 is a schematic diagram of a hydraulic circuit 110 including a suction strainer 1, which is one embodiment of the present invention. In Figure 1, hatching indicating a cross-section has been omitted.
[0019] Tank 100 is installed in a work machine (e.g., a hydraulic system) not shown in the diagram, and is a tank for storing hydraulic fluid located within the hydraulic circuit 110 that supplies hydraulic fluid to the hydraulic system. Note that Tank 100 is not limited to a hydraulic circuit, nor is the liquid stored in Tank 100 limited to hydraulic fluid.
[0020] The tank 100 is, for example, box-shaped and hollow inside. Inside the tank 100, a suction strainer 1 and a return filter (not shown) are mainly provided.
[0021] In the hydraulic circuit 110, hydraulic fluid is introduced into the tank 100 through a hydraulic device (not shown). The tank 100 has an inlet (not shown) that allows the hydraulic fluid to flow into the tank 100. The hydraulic fluid that flows in through the inlet is led to a return filter. The hydraulic fluid is filtered by the return filter and stored in the tank 100.
[0022] An outlet 100c is formed near the lower end of the side surface 100b of the tank 100 (in this embodiment, at a position on the side surface of the tank 100 close to the bottom surface 100a) to allow the hydraulic fluid inside the tank 100 to flow out to the hydraulic pump 103. A suction strainer 1 is provided at the outlet 100c. The suction strainer 1 is cylindrical and is installed along the horizontal direction.
[0023] The suction strainer 1 is provided with a suction pipe 101 that connects from the outside of the tank 100 to the suction port of the hydraulic pump 103. The hydraulic fluid stored in the tank 100 is drawn into the hydraulic pump 103, flows out through the suction strainer 1 to the suction pipe 101, and is then supplied back to the hydraulic system.
[0024] Furthermore, the outlet 100c and the suction strainer 1 only need to be located on the side 100b of the tank 100, and the positions of the outlet 100c and the suction strainer 1 are not limited to those shown in Figure 1.
[0025] Figure 2 shows a schematic diagram of the suction strainer 1 and tank 100. Hereinafter, the extension direction of the suction strainer 1 (the extension direction of the central axis ax of the suction strainer 1) will be referred to as the x direction, and the vertical direction will be referred to as the z direction (vertically upward is the +z direction). The direction perpendicular to the x and z directions will be referred to as the y direction.
[0026] The suction strainer 1 mainly comprises a filtration section 10, a mounting section 20, a plate 30, a cover 40, floats 51 and 52, a baffle plate 61, and a mounting section 70. The mounting section 20 is provided on the side 100b of the tank 100, and the mounting section 70 is provided on the side 100d of the tank 100.
[0027] The mounting portion 70 has a plate-shaped portion 71 and a rod-shaped member 72. When the plate-shaped portion 71 is attached to the side surface 100d, the plate 30 attached to the rod-shaped member 72 is pushed in the -x direction, thereby installing the suction strainer 1 inside the tank 100.
[0028] Figure 3 is a schematic cross-sectional view of the suction strainer 1. In Figure 3, some of the hatching indicating the cross-section has been omitted.
[0029] The filtration section 10 mainly consists of pleated filter media 11 and 12, and inner cylinders 13 and 14. The inner cylinders 13 and 14 are provided inside the pleated filter media 11 and 12, respectively.
[0030] The pleated filter media 11 and 12 are components for filtering hydraulic fluid and are cylindrical in shape (here, cylindrical). The heights of the pleated filter media 11 and 12 are approximately the same. The pleated filter media 11 and 12 are formed by folding a sheet-like thin plate with holes formed almost entirely over it, connecting both ends of the folded thin plate, and rolling it into a cylindrical shape. As a result, the pleated filter media 11 and 12 are formed into a roughly cylindrical pleated shape. In this embodiment, the pleated filter media 12 is formed from a fine-mesh metal (for example, stainless steel) mesh in which fine wires are woven together, but filter paper made of synthetic resin or paper may also be used.
[0031] The diameter of the pleated filter material 12 (corresponding to the second pleated filter material of the present invention) is smaller than the diameter of the pleated filter material 11 (corresponding to the first pleated filter material of the present invention), and the pleated filter material 12 is provided inside the pleated filter material 11.
[0032] The inner cylinders 13 and 14 are cylindrical (here, cylindrical in shape) members with openings at both ends, and are made of a highly corrosion-resistant material (for example, stainless steel). The heights of the inner cylinders 13 and 14 are approximately the same as the heights of the pleated filter media 11 and 12. The diameter of inner cylinder 13 is smaller than the diameter of pleated filter media 11, and inner cylinder 13 is located inside the pleated filter media 11. Similarly, the diameter of inner cylinder 14 is smaller than the diameter of pleated filter media 12, and inner cylinder 14 is located inside the pleated filter media 12.
[0033] The inner cylinders 13 and 14 have holes 13a and 14a formed throughout almost their entire area, through which the hydraulic fluid passes. The hydraulic fluid that has passed through the pleated filter material 11 flows into the inside of the inner cylinder 13 through the holes 13a. The hydraulic fluid that has flowed into the inside of the inner cylinder 13 then passes through the pleated filter material 12, and flows into the inside of the inner cylinder 14 through the holes 14a.
[0034] A mounting portion 20 is provided at one end (-x side) of the filtration section 10, and a plate 30 is provided at the other end (+x side). The mounting portion 20 and the plate 30 are made of a highly corrosion-resistant material (resin or metal).
[0035] The mounting portion 20 is cylindrical overall and is provided on the side surface 100b. The mounting portion 20 is also provided with one end (-x side) of the filtration portion 10.
[0036] The mounting portion 20 mainly consists of a cylindrical first mounting portion 21 provided on the side surface 100b (see Figure 2) and a cylindrical second mounting portion 22 to which the filtration portion 10 is attached.
[0037] The first mounting portion 21 has a cylindrical portion 21a that is inserted into the outlet 100c and a flange portion 21b that abuts against the side surface 100b. A part of the cylindrical portion 21a and the flange portion 21b are provided on the outside of the tank 100.
[0038] The second mounting portion 22 is provided on the first mounting portion 21 and has a cylindrical portion 22a into which the cylindrical portion 21a is inserted, and a plate-shaped portion 22b on which the filtration portion 10 is provided. The second mounting portion 22 is provided inside the tank 100.
[0039] When the plate-shaped portion 71 (not shown in Figure 3) is attached to the side surface 100d, the rod-shaped member 72 pushes the plate 30, i.e., the second mounting portion 22, in the -x direction. As a result, the -x end of the cylindrical portion 22a comes into contact with the side surface 100b, and with the cylindrical portion 21a inserted into the hollow portion of the cylindrical portion 22a, the first mounting portion 21 and the second mounting portion 22 are integrated.
[0040] The cylindrical portion 21a is inserted into the cylindrical portion 22a, and an elastic member 55 (for example, an O-ring) is provided between the cylindrical portion 21a and the cylindrical portion 22a, thereby integrating the hollow portion 21c of the cylindrical portion 21a and the hollow portion 22e of the cylindrical portion 22a. The hollow portions of the mounting portion 20, namely the hollow portions 21c and 22e, connect the hollow portion (space S3) of the filtration portion 10 to the outside of the tank 100 (the inside of the suction pipe 101).
[0041] The plate-shaped portion 22b has recesses 22c and 22d. A pleated filter material 11 and an inner cylinder 13 are provided in recess 22c, and a pleated filter material 12 and an inner cylinder 14 are provided in recess 22d. As a result, a filtration section 10 is provided on the mounting portion 20, and the filtration section 10 extends along the horizontal direction.
[0042] The plate-shaped portion 22b is provided with an air vent hole 22f. The air vent hole 22f is located at the upper vertical end of the plate-shaped portion 22b. The air vent hole 22f connects the hollow portion 22e with the external space of the mounting portion 20 (in this case, space S1). Here, space S1 is the space between the filtration portion 10 and the mounting portion 20 and the cover 40.
[0043] A float 51 is provided at the upper end of the air vent hole 22f. The float 51 is movable vertically (in the z direction) between a position that closes the air vent hole 22f and a position that opens the air vent hole 22f. When air bubbles flowing into the air vent hole 22f from the hollow part of the mounting part 20 or the suction pipe 101 flow into the air vent hole 22f and grow inside the air vent hole 22f, pushing the float 51 upward in the +z direction, the air vent hole 22f opens. This allows the air accumulated in the hollow part of the mounting part 20 or the suction pipe 101 to be discharged into the space S1 via the air vent hole 22f.
[0044] The cover 40 is a cylindrical member that extends horizontally. A strip-shaped area along the horizontal direction, located near the lower end of the cover 40, is provided with multiple holes 40a. Note that the cover 40 is not essential.
[0045] The cover 40 has one end attached to the side surface 100b and the other end attached to the plate 30. That is, the plate 30 covers the edges (openings) of the filtration section 10 and the cover 40. As a result, the hydraulic fluid flows from the hole 40a into space S1 and from the filtration section 10 into spaces S2 and S3. Here, space S2 is the space between the pleated filter material 11 and the pleated filter material 12.
[0046] The cover 40 is provided with a hole (not shown), and a float 52 is provided in this hole. The float 52 is movable in the vertical direction (z direction) between a position that closes the hole and a position that opens the hole.
[0047] The baffle plate 61 (corresponding to the first baffle plate of the present invention) is provided inside the filtration section 10. The baffle plate 61 is cylindrical in shape overall, with one end provided on the mounting section 20. The baffle plate 61 mainly consists of a cylindrical air reservoir section 61a and a cylindrical extension tube 61b provided on the air reservoir section 61a. The radius of the air reservoir section 61a is large on the mounting section 20 side and gradually decreases as it approaches the plate 30. The radius of the extension tube 61b is the same as the minimum radius of the air reservoir section 61a. Note that the extension tube 61b is not essential.
[0048] Next, the function of the suction strainer 1 configured in this way will be explained using Figure 3. The suction strainer 1 is mounted horizontally in the tank 100, and then the hydraulic fluid is stored in the tank 100.
[0049] Since a mounting portion 20 is provided at one end of the filtration section 10 and a plate 30 is provided at the other end, when the hydraulic fluid stored in the tank 100 is drawn into the hydraulic pump 103 (not shown in Figure 3), as indicated by the white arrow in Figure 3, it is drawn into space S1 through the hole 40a from the outside of the cover 40, drawn into space S2 through the pleated filter material 11 and the inner cylinder 13, drawn into space S3 through the pleated filter material 12 and the inner cylinder 14 from space S2, and flows out into the suction pipe 101 through the hollow sections 21c and 22e from space S3.
[0050] Furthermore, because the hydraulic pump 103 draws in the hydraulic fluid, the floats 51 and 52 are pulled in the -z direction along with the hydraulic fluid, causing float 51 to contact the plate-shaped portion 22b and block the air vent hole 22f, and float 52 to block the hole in the cover 40. As a result, hydraulic fluid does not flow into the space S3 from any source other than the hole 40a and the filtration section 10.
[0051] When the hydraulic fluid is drawn into space S3, the air bubbles V1 contained in the hydraulic fluid are also drawn into the filtration section 10 along with the hydraulic fluid. The air bubbles V1 flow in the +z and -x directions along with the flow of the hydraulic fluid (see the dotted arrows (shaded) in Figure 3) and come into contact with the baffle plate 61. The air bubbles V1 then accumulate in the space between the baffle plate 61 (air reservoir 61a) and the filtration section 10, and on the upper side (+z side) of the baffle plate 61, and grow into large air bubbles V2.
[0052] When the hydraulic pump 103 (not shown in Figure 3) stops, the flow of hydraulic fluid stops. As a result, the bubbles V2 that have accumulated on the upper side of the baffle plate 61 are discharged into space S1 via the filtration section 10. When the bubbles V2 are discharged into space S1 and grow, pushing the float 52 upward in the +z direction, the holes in the cover 40 open, and air is released from space S1 to the outside of the suction strainer 1.
[0053] According to this embodiment, the baffle plate 61 prevents bubbles V1 that have flowed into space S3 from flowing out of the suction strainer 1, which is installed along the horizontal direction, by keeping the bubbles V2 in space S3. As a result, it is possible to prevent bubbles from accumulating in the suction pipe 101 and malfunctions caused by the pump sucking in air. In addition, it is possible to prevent damage to parts caused by bubbles bursting in the hydraulic circuit, which would temporarily cause the temperature and pressure of the hydraulic fluid to rise to an extreme level.
[0054] Furthermore, according to this embodiment, since the mounting portion 20 has a large radius on the mounting portion 20 side and the radius gradually decreases as it approaches the plate 30, an upward force is applied to the air bubble V2 that comes into contact with the air bubble V2, making it difficult for the air bubble V2 to flow into the hollow portion of the mounting portion 20.
[0055] Furthermore, according to this embodiment, even if air bubbles accumulate in the suction pipe 101, the bubbles can be discharged through the air vent hole 22f.
[0056] Furthermore, according to this embodiment, since the baffle plate 61 is cylindrical, even if the bubble V1 flows in the -x direction before rising in the +z direction, the baffle plate 61 blocks the bubble V1, and it can become bubble V2 on the upper side of the baffle plate 61. Therefore, it is possible to prevent bubbles from flowing out of the suction strainer 1.
[0057] Furthermore, according to this embodiment, since a cover 40 is provided with multiple holes 40a formed in a horizontally oriented band-shaped region located near the lower end, bubbles formed when flowing from the return filter into the tank are less likely to collide with the filtration section 10. As a result, the number of bubbles V1 that collide with the filtration section 10 is reduced, and the inflow of bubbles V1 into the space S3 can be reduced.
[0058] In this embodiment, the baffle plate 61 was cylindrical, but the baffle plate 61 is not limited to a cylindrical shape. The baffle plate only needs to be positioned above the central axis ax of the filtration section 10. Figure 4 is a schematic diagram of a suction strainer 1A having a baffle plate 61A that is semicircular in cross-section. Note that in Figure 4, some of the hatching indicating the cross-section is omitted.
[0059] The only difference between suction strainer 1A and suction strainer 1 is the baffle plate 61A. The baffle plate 61A (corresponding to the first baffle plate of the present invention) is provided inside the filtration section 10. The cross-sectional shape of the baffle plate 61A when cut by a plane perpendicular to the central axis ax (a plane parallel to the yz plane, corresponding to the first plane of the present invention) is semicircular. In other words, the baffle plate 61A only needs to be positioned above the central axis ax of the filtration section 10, and a part of the baffle plate 61A may be positioned at the same height as the central axis ax, or it may be positioned below the central axis ax.
[0060] The baffle plate 61A has an air reservoir 61c and an extension 61d provided on the air reservoir 61c. The air reservoir 61c is half of the air reservoir 61a on the +z side, and is inclined such that the radius is large on the mounting portion 20 side and gradually decreases as it approaches the plate 30. The extension 61d is half of the extension tube 61b on the +z side. The radius of the extension 61d is the same as the minimum radius of the air reservoir 61a. The air reservoir 61c and the extension 61d intersect the line segment connecting the upper end of the filtration portion 10 and the central axis ax. Note that the extension 61d is not essential.
[0061] Furthermore, the cross-sectional shape of the baffle plate 61A when cut by a plane perpendicular to the central axis ax is not limited to a semicircular shape, but can be an arc shape. In other words, the baffle plate 61A can be a part of the +z side of the baffle plate 61, and the baffle plate 61A can intersect with the line segment connecting the upper end of the filtration section 10 and the central axis ax.
[0062] This prevents bubbles from flowing out of the suction strainer 1A by using the baffle plate 61A to retain bubbles V2 in space S3, which in turn prevents bubbles V1 that have flowed into space S3 from flowing out of space S3.
[0063] <Second Embodiment> In the first embodiment of the present invention, the filtration unit 10 has two pleated filter media 11 and 12, but the number of pleated filter media in the filtration unit 10 is not limited to this.
[0064] A second embodiment of the present invention is a configuration in which the filtration section has one pleated filter medium. The suction strainer 2 according to the second embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0065] Figure 5 is a schematic cross-sectional view of the suction strainer 2. In Figure 5, the hatching indicating the cross-section is omitted.
[0066] The suction strainer 2 mainly comprises a filtration section 10A, a mounting section 20A, a plate 30A, a float 53, and a baffle plate 61. The mounting section 20A is provided on the side 100b (not shown in Figure 5) of the tank 100 (not shown in Figure 5).
[0067] The filtration section 10A comprises a pleated filter medium 12 and an inner cylinder 14. A mounting section 20A is provided at one end of the filtration section 10A (the -z end), and a plate 30A is provided at the other end (the +z end). The mounting section 20A and the plate 30A each cover the end of the filtration section 10A.
[0068] The mounting portion 20A mainly consists of a cylindrical portion 20a into which the suction pipe 101 (not shown in Figure 5) is inserted, a flange portion 20b that abuts against the side surface 100b, a mounting portion 20d for attaching the filtration portion 10A, and a cylindrical portion 20f between the flange portion 20b and the mounting portion 20d. The cylindrical portion 20f is inserted into the outlet 100c, and the mounting portion 20d is provided inside the tank 100.
[0069] The mounting portion 20d has a recess 20e into which the filter portion 10A is inserted. When the filter portion 10A is placed in the recess 20e, the filter portion 10A is installed inside the tank 100 along the horizontal direction (in this case, the x-direction).
[0070] The cylindrical portion 20a is provided with an air vent hole 20g. The air vent hole 20g is located at the upper vertical end of the cylindrical portion 20a. The air vent hole 20g connects the hollow portion 20c of the cylindrical portion 20a with the external space of the cylindrical portion 20a.
[0071] A float 53 is provided at the upper end of the air vent hole 20g. The float 53 is movable vertically (in the z direction) between a position that closes the air vent hole 20g and a position that opens the air vent hole 20g. When air bubbles flowing into the air vent hole 20g from the hollow section 20c or the suction pipe 101 (not shown in Figure 5) flow into the air vent hole 20g and grow inside the air vent hole 20g, pushing the float 53 upward in the +z direction, the air vent hole 20g opens. This allows air accumulated in the hollow section of the mounting section 20 or the suction pipe 101 to be discharged to the outside of the mounting section 20A through the air vent hole 20g.
[0072] The baffle plate 61 is positioned inside the filtration section 10A. One end of the baffle plate 61 is provided on the mounting section 20A.
[0073] Next, the function of the suction strainer 2 configured in this way will be explained. The suction strainer 2 is mounted horizontally in the tank 100, and then the hydraulic fluid is stored in the tank 100.
[0074] Since a mounting portion 20A is provided at one end of the filtration section 10A and a plate 30A is provided at the other end, when the hydraulic fluid stored in the tank 100 is drawn in by the hydraulic pump 103 (not shown in Figure 5), it is drawn into space S3 through the pleated filter material 12 and the inner cylinder 14, and flows out of space S3 through the hollow section 20c to the suction pipe 101. Also, because the hydraulic fluid is drawn in by the hydraulic pump 103, the float 53 is pulled in the -z direction along with the hydraulic fluid, and the float 53 blocks the air vent hole 20g. As a result, hydraulic fluid does not flow into space S3 from anywhere other than the filtration section 10A.
[0075] When the hydraulic fluid is drawn into space S3, the air bubbles V1 contained in the hydraulic fluid are also drawn into the filtration section 10 along with the hydraulic fluid. The air bubbles V1 flow in the +z and -x directions along with the flow of the hydraulic fluid and come into contact with the baffle plate 61. The air bubbles V1 then accumulate in the space above (+z side of) the baffle plate 61 and grow into larger air bubbles V2. This makes it difficult for the air bubbles V2 to flow out into the hollow section 20c.
[0076] When the hydraulic pump 103 stops, the flow of hydraulic fluid stops. As a result, the air bubbles V2 that have accumulated above the baffle plate 61 are discharged into the space S1 via the filtration section 10A.
[0077] According to this embodiment, the baffle plate 61 keeps the bubbles V2 that have flowed into the space S3 in the space S3, thereby preventing bubbles from flowing out of the suction strainer 2 which is installed along the horizontal direction.
[0078] <Third Embodiment> In the first embodiment of the present invention, the baffle plate 61 has an air reservoir 61a and an extension tube 61b, but the form of the baffle plate is not limited to this. In the third embodiment of the present invention, the baffle plate has an upper cover. The suction strainer 3 according to the third embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0079] Figure 6 is a schematic diagram of the suction strainer 3, where (A) is a cross-sectional view and (B) is a cross-sectional view of the suction strainer 3 cut along plane AA. In Figure 6, some of the hatching indicating the cross-section is omitted.
[0080] The suction strainer 3 mainly comprises a filtration section 10, a mounting section 20, a plate 30, a cover 40, floats 51 and 52, a baffle plate 61B, and a mounting section 70 (partially omitted in Figure 6).
[0081] The baffle plate 61B (corresponding to the first baffle plate of the present invention) is provided inside the filtration section 10. One end of the baffle plate 61B is provided on the mounting section 20. The baffle plate 61B mainly consists of a cylindrical air reservoir 61a, a cylindrical extension tube 61b, and an upper cover 61e.
[0082] The upper cover 61e is located on the plate 30 side of the air reservoir 61a. In this embodiment, one end of the upper cover 61e is attached to the extension tube 61b, but if the extension tube 61b is not provided, the upper cover 61e can be attached to the air reservoir 61a.
[0083] The upper cover 61e has an arc-shaped cross-section when cut along a plane perpendicular to the central axis ax (section AA). In this embodiment, the central angle θ1 of the upper cover 61e is approximately 90 degrees in section AA. Furthermore, the upper cover 61e is positioned at a location where it intersects with the line segment connecting the upper end of the filtration section 10 and the central axis ax when cut along a plane perpendicular to the central axis ax (section AA).
[0084] Next, the function of the suction strainer 3 configured in this way will be explained. The suction strainer 3 is mounted horizontally in the tank 100, and then the hydraulic fluid is stored in the tank 100.
[0085] Similar to the suction strainer 1, the hydraulic fluid stored in the tank 100 is drawn into the space S3 from the outside of the cover 40 through the hole 40a and the filter section 10 when it is sucked into the hydraulic pump 103 (not shown in Figure 6). From the space S3, it flows out into the suction pipe 101 through the hollow sections 21c and 22e. The floats 51 and 52 are also pulled in the -z direction along with the hydraulic fluid, with float 51 blocking the air vent hole 22f and float 52 blocking the hole in the cover 40. As a result, hydraulic fluid does not flow into the space S3 from anywhere other than the hole 40a and the filter section 10.
[0086] The air bubbles V1 contained in the hydraulic fluid are also drawn into the space S3 along with the hydraulic fluid. The air bubbles V1 that flow into the space S3 from below the filtration section 10 flow in the +z and -x directions along with the flow of the hydraulic fluid and come into contact with the air reservoir section 61a.
[0087] Furthermore, bubbles V1 contained in the hydraulic fluid flowing into spaces S2 and S3 from above or diagonally above the filtration section 10 collide with the upper cover 61e, flow along the upper cover 61e in the -x direction, and come into contact with the air reservoir section 61a. The bubbles V1 then accumulate in the space above the air reservoir section 61a and grow into larger bubbles V2.
[0088] When the hydraulic pump 103 (not shown in Figure 6) stops, the bubbles V2 that have accumulated on the upper side of the baffle plate 61B are discharged into space S1 via the filtration unit 10. As the bubbles V2 are discharged into space S1 and grow, pushing the float 52 upward in the +z direction, the holes in the cover 40 open, and air is released from space S1 to the outside of the suction strainer 3.
[0089] According to this embodiment, the baffle plate 61B prevents bubbles V1 that have flowed into the space S3 from flowing out of the suction strainer 3, which is provided along the horizontal direction, by keeping the bubbles V2 in the space S3. Furthermore, by providing the upper cover 61e, more bubbles V1 can be accumulated in the space above the air reservoir 61a, and as a result, the amount of bubbles flowing out of the suction strainer 3 can be further reduced.
[0090] In this embodiment, the central angle θ1 of the upper cover 61e in the AA cross-section was approximately 90 degrees, but the central angle of the upper cover is not limited to this. Figure 7 is a schematic diagram of a suction strainer 3A having a baffle plate 61C according to a modified example, where (A) is a cross-sectional view and (B) is a cross-sectional view of the suction strainer 3A cut at the BB plane. Note that in Figure 7, some of the hatching indicating the cross-section is omitted.
[0091] The only difference between the suction strainer 3A and the suction strainer 3 is the baffle plate 61C. The baffle plate 61C (corresponding to the first baffle plate of the present invention) mainly consists of a cylindrical air reservoir 61a, a cylindrical extension tube 61b, and an upper cover 61f.
[0092] The upper cover 61f is located on the plate 30 side of the air reservoir 61a. The difference between the upper cover 61f and the upper cover 60c is the central angle. In the BB cross section, the central angle θ2 of the upper cover 61f is approximately 120 degrees.
[0093] Furthermore, the central angle of the upper cover is not limited to 90 degrees or 120 degrees. Considering that the air bubble V1 rises in the +z direction due to buoyancy, it is sufficient that the upper cover is positioned so as to intersect the line segment connecting the upper end of the filtration section 10 and the central axis ax.
[0094] <Fourth Embodiment> In the first embodiment of the present invention, the baffle plate 61B has an air reservoir 61a, an extension tube 61b, and an upper cover 61e, but the form of the baffle plate is not limited thereto. The suction strainer 4 according to the fourth embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0095] Figure 8 is a schematic cross-sectional view of the suction strainer 4. In Figure 8, some of the hatching indicating the cross-section has been omitted.
[0096] The suction strainer 4 mainly comprises a filtration section 10, a mounting section 20, a plate 30, a cover 40, floats 51 and 52, a baffle plate 61D, and a mounting section 70 (partially omitted in Figure 8).
[0097] The baffle plate 61D (corresponding to the first baffle plate of the present invention) is provided inside the filtration section 10. One end of the baffle plate 61D is provided on the mounting section 20. The baffle plate 61D mainly has a cylindrical air reservoir section 61a and a cylindrical extension tube 61h.
[0098] The extension tube 61h is located on the plate 30 side of the air reservoir 61a. The extension tube 61h has a strip-shaped region 61i with numerous holes 61j. The strip-shaped region 61i is located on the lower side (-z side) of the extension tube 61h, in a strip shape along the x direction. The -x side of the strip-shaped region 61i is the cylindrical portion 61g, and the +z side of the strip-shaped region 61i is the upper cover 61k.
[0099] The upper cover 61k has an arc-shaped cross-section when cut by a plane perpendicular to the central axis ax. Furthermore, the upper cover 61k is positioned at a location where it intersects with the line segment connecting the upper end of the filtration section 10 and the central axis ax when cut by a plane perpendicular to the central axis ax.
[0100] The position and shape of the band-shaped region 61i are not limited to this. For example, the cylindrical portion 61g is not essential. Also, the central angle of the upper cover 61k is 120 degrees, but the central angle is not limited to this.
[0101] According to this embodiment, the baffle plate 61D keeps the bubbles V2 that have flowed into the space S3 in the space S3, thereby preventing bubbles from flowing out of the suction strainer 4 which is installed along the horizontal direction. Furthermore, by providing the upper cover 61k, the amount of bubbles flowing out of the suction strainer 4 can be further reduced.
[0102] Furthermore, according to this embodiment, the assembly process is made easier by making the upper cover 61k part of the extension tube 61h.
[0103] <Fifth Embodiment> In the first embodiment of the present invention, the baffle plate 61 was provided inside the filtration section 10, but the form of the baffle plate is not limited to this. In the fifth embodiment of the present invention, the baffle plate is provided outside the pleated filter media 12. The suction strainer 5 according to the fifth embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0104] Figure 9 is a schematic diagram of the suction strainer 5, where (A) is a cross-sectional view and (B) is a perspective view. In Figure 9, some hatching indicating the cross-section is omitted. Also, in Figure 9(B), part of the filtration section 10 and the cover 40 are omitted for illustrative purposes.
[0105] The suction strainer 5 mainly comprises a filtration section 10, a mounting section 20, a plate 30, a cover 40, floats 51 and 52, baffles 61C and 62, and a mounting section 70 (partially omitted in Figure 9).
[0106] The baffle plate 62 (corresponding to the second baffle plate of the present invention) is provided on the lower side (-z side) of the pleated filter material 12 and on the lower side of the central axis ax. In this embodiment, the baffle plate 62 is provided on the outside of the pleated filter material 12 and on the inside of the pleated filter material 11. The baffle plate 62 has the same height as the filtration section 10, with one end provided on the mounting section 20 and the other end provided on the plate 30.
[0107] Figure 10 is a schematic cross-sectional view showing the suction strainer 5 when cut along the CC cross-section of Figure 9(A). The baffle plate 62 is a lower cover that has an arc-shaped cross-section when cut along a plane perpendicular to the central axis ax, and is located at a position that intersects with the line segment connecting the lower end of the filtration section 10 and the central axis ax. In the CC cross-section, the central angle θ3 of the baffle plate 62 is approximately 90 degrees.
[0108] The baffle plate 62 is provided adjacent to the pleated filter material 12 and along the pleated filter material 12. Furthermore, the baffle plate 62 is provided so as not to come into contact with the pleated filter material 12.
[0109] Next, the function of the suction strainer 5 configured in this way will be explained using Figure 9. The suction strainer 5 is mounted horizontally in the tank 100, and then the hydraulic fluid is stored in the tank 100.
[0110] Similar to the suction strainer 1, the hydraulic fluid stored in the tank 100 is drawn into the space S3 from the outside of the cover 40 through the hole 40a and the filter section 10 when it is sucked into the hydraulic pump (not shown in Figure 9). From the space S3, it flows out into the suction pipe 101 through the hollow sections 21c and 22e. The floats 51 and 52 are pulled in the -z direction along with the hydraulic fluid, with float 51 blocking the air vent hole 22f and float 52 blocking the hole in the cover 40. As a result, the hydraulic fluid does not flow into the space S3 from anywhere other than the hole 40a and the filter section 10.
[0111] The air bubbles V1 contained in the hydraulic fluid are also drawn into space S3 along with the hydraulic fluid. The hydraulic fluid that flows into space S1 from hole 40a and into space S2 from below the filtration section 10 is blocked by the baffle plate 62 and flows along the baffle plate 62 (see arrow in Figure 9(B)). In particular, when the hydraulic fluid passes through the pleated filter material 11 from below the filtration section 10, the air bubbles V1 that pass through the pleated filter material 11 together with the hydraulic fluid are blocked on the lower side of the baffle plate 62, making it difficult for the air bubbles V1 to flow into space S3.
[0112] Even if bubbles V1 flow into space S3, they will flow in the +z and -x directions along with the flow of hydraulic fluid, come into contact with the air reservoir 61a, and grow into large bubbles V2. Similarly, bubbles V1 contained in hydraulic fluid flowing into spaces S2 and S3 from above or diagonally above the filtration unit 10 will also collide with the upper cover 61f, flow along the upper cover 61f in the -x direction, come into contact with the air reservoir 61a, and grow into large bubbles V2. When the hydraulic pump (not shown in Figure 9) stops, the bubbles V2 are discharged into space S1 via the filtration unit 10.
[0113] According to this embodiment, the baffle plate 62 blocks the bubbles V1, making it difficult for bubbles V1 to flow into the space S3, thereby preventing bubbles from flowing into the hollow part (space S3) of the filtration section 10. Furthermore, even if bubbles V1 do flow into space S3, the baffle plate 61C can retain the bubbles V2 in space S3. As a result, it is possible to prevent bubbles from flowing out of the suction strainer 5.
[0114] In this embodiment, the suction strainer 5 has baffle plates 61C and 62, but baffle plate 61C is not essential. Even if the suction strainer 5 has only baffle plate 62, the effect of preventing air bubbles from flowing out of the suction strainer 5 can be obtained.
[0115] Furthermore, in this embodiment, the baffle plate 62 was provided on the outside of the pleated filter material 12 and on the inside of the pleated filter material 11, but the position of the baffle plate (lower cover) is not limited to this. The baffle plate (lower cover) only needs to be provided on the lower side (-z side) of the pleated filter material 12 and on the lower side of the central axis ax. For example, as shown in Figure 10, the baffle plate 62A (corresponding to the second baffle plate of the present invention) may be a lower cover provided on the outside of the pleated filter material 11.
[0116] Furthermore, in this embodiment, the central angle θ3 of the baffle plate 62 was approximately 90 degrees, but the central angle of the baffle plate (lower cover) is not limited to this. Figures 11 and 12 show schematic diagrams of suction strainers 5A and 5B having baffle plates 62B and 62C according to modified examples, where (A) is a perspective view and (B) is a cross-sectional view when cut by a plane perpendicular to the central axis ax. Note that in Figures 11 and 12, some hatching indicating the cross-section is omitted. Also, in Figures 11(A) and 12(A), some components are omitted.
[0117] The baffles 62B and 62C (both corresponding to the second baffle of the present invention) are lower covers that, like the baffle 62, have an arc-shaped cross-section when cut by a plane perpendicular to the central axis ax, and are positioned at an intersection with the line segment connecting the lower end of the filtration section 10 and the central axis ax. The baffles 62B and 62C differ from the baffle 62 only in their central angles. As shown in Figure 11, the central angle θ4 of the baffle 62B is approximately 120 degrees, and as shown in Figure 12, the central angle θ5 of the baffle 62C is approximately 180 degrees. In other words, the baffle (lower cover) only needs to be positioned below the central axis ax of the filtration section 10, and a part of the baffle (lower cover) may be positioned at the same height as the central axis ax.
[0118] <Sixth Embodiment> In the fifth embodiment of the present invention, the filtration unit 10 has two pleated filter media 11 and 12, but the number of pleated filter media in the filtration unit 10 is not limited to this.
[0119] A sixth embodiment of the present invention is a configuration in which the filtration section has one pleated filter medium. The suction strainer 6 according to the sixth embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0120] Figure 13 is a schematic cross-sectional view of the suction strainer 6. In Figure 13, the hatching indicating the cross-section is omitted.
[0121] The suction strainer 6 mainly comprises a filtration section 10A, a mounting section 20A, a plate 30A, a float 53, and a baffle plate 62. The baffle plate 62 is provided adjacent to the pleated filter material 12 of the filtration section 10A and along the pleated filter material 12. The baffle plate 62 is also provided so as not to come into contact with the pleated filter material 12.
[0122] According to this embodiment, the baffle plate 62 blocks the bubbles V1, making it difficult for bubbles V1 to flow into the space S3, thereby preventing bubbles from flowing into the hollow part (space S3) of the filtration section 10A, and thus preventing bubbles from flowing out of the suction strainer 6 which is provided along the horizontal direction.
[0123] <Seventh Embodiment> In the first embodiment of the present invention, the bubbles V2 accumulated on the air reservoir 61a were discharged through the filtration unit 10 after the hydraulic pump was stopped, but the form of discharge of the bubbles V2 is not limited to this. In the seventh embodiment of the present invention, the bubbles V2 are discharged through an air vent hole. The suction strainer 7 according to the seventh embodiment will be described below. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0124] Figure 14 is a schematic cross-sectional view of the suction strainer 7. In Figure 14, some of the hatching indicating the cross-section has been omitted.
[0125] The suction strainer 7 mainly comprises a filtration section 10, a mounting section 20, a plate 30, a cover 40, floats 51 and 52, a baffle plate 61E, and a mounting section 70 (partially omitted in Figure 14).
[0126] The baffle plate 61E (corresponding to the first baffle plate of the present invention) is provided inside the filtration section 10. Like the baffle plate 61, the baffle plate 61E has a cylindrical air reservoir 61l and a cylindrical extension tube 61m provided in the air reservoir 61l.
[0127] The baffle plate 61E is inserted into the hollow portion 22e of the cylindrical portion 22a, with one end provided in the cylindrical portion 21a. Therefore, the space above the air reservoir 61l is in communication with the air vent hole 22f.
[0128] In the suction strainer 7, as in the suction strainer 1, the bubbles V1 that are drawn into the filtration section 10 along with the hydraulic fluid flow in the +z and -x directions along with the flow of the hydraulic fluid and come into contact with the baffle plate 61E. The bubbles V1 then accumulate in the space above the baffle plate 61E (air reservoir 61l) and grow into larger bubbles V2. The bubbles V2 flow into the air vent hole 22f and push the float 52 upward in the +z direction, causing the hole in the cover 40 to open and the bubbles V2 to be released from the space S1 to the outside of the suction strainer 1.
[0129] According to this embodiment, by blocking the bubbles V2 with the baffle plate 61E, it is possible to prevent bubbles from flowing out of the suction strainer 7, which is provided along the horizontal direction. Furthermore, by connecting the space above the air reservoir 61l with the air vent hole 22f, bubbles V2 can be discharged into the space S1 even during operation (while the hydraulic pump 103 is operating).
[0130] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the gist of this invention. For example, the above embodiments are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace some of the configurations of an embodiment with those of another embodiment, and it is also possible to add, delete, or replace other configurations in an embodiment.
[0131] Furthermore, in this invention, "approximately" is a concept that includes not only cases where the two are strictly identical, but also errors or modifications that do not result in a loss of identity. For example, "approximately orthogonal" is a concept that includes errors of, for example, a few degrees, and is not limited to cases where the two are strictly orthogonal. Also, for example, when simply using terms such as orthogonal, parallel, or coincident, it includes not only cases where the two are strictly orthogonal, parallel, or coincident, but also cases where they are approximately parallel, approximately orthogonal, or approximately coincident.
[0132] Furthermore, in this invention, "neighborhood" means a region that includes a certain range (which can be arbitrarily defined) near a reference position. For example, when we say "neighborhood of an edge," it refers to a region that is near an edge, and may or may not include the edge. [Explanation of Symbols]
[0133] 1, 1A, 2, 3, 3A, 4, 5, 5A, 5B, 6, 7: Suction Strainer 10, 10A: Filtration section 11, 12: Pleated filter media 13, 14: Inner cylinder 13a, 14a: hole 20, 20A: Mounting section 20a: Cylindrical part 20b: Flange section 20c: Hollow part 20d: Mounting part 20e: recessed 20f: Cylindrical part 20g: Air vent hole 21: First mounting section 21a: Cylindrical part 21b: Flange section 21c: Hollow part 22: Second mounting section 22a: Cylindrical part 22b: Plate-like part 22c, 22d: recessed 22e: Hollow part 22f: Air vent 30, 30A: Plate 40: Cover 40a: hole 51, 52, 53: Float 55: Elastic member 60c: Top cover 61, 61A, 61B, 61C, 61D, 61E: Baffle 61a, 61l: Air reservoir section 61b, 61m: Extension tube 61c: Air reservoir 61d: Extension part 61e, 61f: Top cover 61g: cylindrical part 61h: Extension tube 61i: Band-shaped region 61j: hole 61k: Top cover 62, 62A, 62B, 62C: Baffle boards 70: Mounting part 71: Plate-like part 72: Rod-shaped member 100: Tank 100a: Bottom surface 100b: Side 100c: Outlet 100d: Side view 101: Suction pipe 103: Hydraulic pump 110: Hydraulic Circuit 150:Filtration section
Claims
1. A suction strainer installed in a tank where liquid is stored, A cylindrical filter section having a cylindrical pleated filter material formed by bending a thin plate into a pleated shape, A cylindrical mounting portion provided on the side of the tank, wherein one end of the filtration portion is provided on the mounting portion, A plate that covers the end of the filtration unit on the side where the mounting portion is not provided, A baffle plate having at least one of a first baffle plate provided inside the pleated filter material and a second baffle plate provided outside the pleated filter material, Equipped with, The aforementioned filtration section is provided along the horizontal direction, The filtration section and the plate are provided inside the tank. The first baffle plate is positioned such that at least a portion of it is above the central axis of the filtration section. The second baffle plate is a lower cover that, when cut by a first plane perpendicular to the central axis, has a circular arc cross-sectional shape and is positioned at a location that intersects with the line segment connecting the lower end of the filtration section and the central axis. A suction strainer characterized by the following features.
2. The first baffle plate has a cylindrical air reservoir at one end, which is provided at the mounting portion. The radius of the air reservoir is larger on the mounting side and gradually decreases as it approaches the plate. The suction strainer according to feature 1.
3. The first baffle plate, when cut by a first plane perpendicular to the central axis, has a cross-sectional shape that is arc-shaped and has an air reservoir that intersects with the line segment connecting the upper end of the filtration section and the central axis. The aforementioned air reservoir is provided at one end of the mounting portion. The radius of the air reservoir is larger on the mounting side and gradually decreases as it approaches the plate. The suction strainer according to feature 1.
4. The first baffle plate, when cut by a first plane perpendicular to the central axis, has a cross-sectional shape that is arc-shaped, and has an upper cover provided at a position that intersects with the line segment connecting the upper end of the filtration section and the central axis. The upper cover is provided on the plate side of the air reservoir. The suction strainer according to claim 2 or 3, characterized in that it is as described above.
5. The pleated filter material comprises a cylindrical first pleated filter material and a material provided inside the first pleated filter material. It has a cylindrical second pleated filter material, The first baffle plate is provided inside the second pleated filter media, The second baffle plate is provided on the outside of the second pleated filter material. A suction strainer according to any one of claims 1 to 4.
6. The mounting portion has an air vent hole that connects the hollow portion of the mounting portion to the external space of the mounting portion. A system is in place, A float is provided in the aforementioned air vent hole so as to be movable between a position that closes the air vent hole and a position that opens the air vent hole. A suction strainer according to any one of claims 1 to 5, characterized in that it is the same as described in the previous claim.
7. It comprises a cylindrical cover, one end of which is provided on the mounting portion and the other end of which is provided on the plate, The cover is provided along the horizontal direction, Multiple holes are provided in a horizontal, band-shaped region located near the lower end of the cover. A suction strainer according to any one of claims 1 to 6, characterized by the above.