WO2020031775A1 - Suction filter - Google Patents

Suction filter Download PDF

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Publication number
WO2020031775A1
WO2020031775A1 PCT/JP2019/029668 JP2019029668W WO2020031775A1 WO 2020031775 A1 WO2020031775 A1 WO 2020031775A1 JP 2019029668 W JP2019029668 W JP 2019029668W WO 2020031775 A1 WO2020031775 A1 WO 2020031775A1
Authority
WO
WIPO (PCT)
Prior art keywords
cover
valve body
valve
suction filter
filtration unit
Prior art date
Application number
PCT/JP2019/029668
Other languages
French (fr)
Japanese (ja)
Inventor
信 石塚
Original Assignee
ヤマシンフィルタ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤマシンフィルタ株式会社 filed Critical ヤマシンフィルタ株式会社
Publication of WO2020031775A1 publication Critical patent/WO2020031775A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
    • B01D29/05—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements supported
    • B01D29/07—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements supported with corrugated, folded or wound filtering sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
    • B01D35/02—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
    • B01D35/14—Safety devices specially adapted for filtration; Devices for indicating clogging
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D36/00—Filter circuits or combinations of filters with other separating devices
    • B01D36/02—Combinations of filters of different kinds
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/20—Filtering

Definitions

  • the present invention relates to a suction filter.
  • Patent Literature 1 includes a filter portion that is disposed in a hydraulic oil tank and purifies hydraulic oil in the hydraulic oil tank, and a rod portion connected to the filter portion and extending upward, A suction filter in which an upper end of a rod portion is held by a cover portion that covers an opening of a hydraulic oil tank is disclosed.
  • the present invention has been made in view of such circumstances, and has as its object to provide a suction filter capable of preventing occurrence of cavitation and occurrence of erosion in a pump.
  • a suction filter according to the present invention is, for example, a suction filter that is provided in a tank in which oil is stored, and that filters a liquid sucked into a pump from the tank, and includes a warp yarn.
  • a substantially cylindrical first filtration unit formed by bending a mesh-like thin plate crossing a weft into a pleated shape, and provided on the upper end surface of the first filtration unit, covering the entire upper side of the first filtration unit.
  • a cover a lower plate provided on a lower end surface of the first filtration unit, and covering an entire lower side of the first filtration unit, the lower plate having an outlet through which the liquid flows out to the pump; And a valve provided in a hollow portion of the first filtration unit, wherein the cover has a hole, and the valve has a rod-shaped member erected on the cover and a rod-shaped member.
  • the bar-shaped part provided And a resilient member provided at both ends of the first valve body and the rod-shaped member to push up the first valve body toward the cover.
  • the first valve body Is configured to switch between a closed state in which the hole is closed and an open state in which the first valve body does not close the hole.
  • a valve is provided on the upper end surface of the first filtration unit, below the cover that covers the entire upper side of the first filtration unit, and in the hollow portion of the first filtration unit.
  • the valve has a first valve body movable along the rod-shaped member, and an elastic member provided at both ends of the first valve body and the rod-shaped member, and for pushing up the first valve body toward the cover.
  • an air hole is formed in the first valve body, and the valve has a second valve body provided on the rod-shaped member and movable along the rod-shaped member. , May be provided between the first valve body and the cover, and may be movable between a position covering the air hole and a position not covering the air hole. Thereby, the air in the suction filter can be discharged.
  • the cover has a plate-shaped portion, and a protrusion provided on the plate-shaped portion and protruding on a side opposite to the first filtering portion. Is open at the lower end surface of the cover, and when the valve is in the closed state, the first valve body contacts the lower end surface of the cover so as to cover the cavity, and the second valve body is It may be provided inside the cavity. This makes it difficult for air to accumulate inside the suction filter, and allows the air in the suction filter to be discharged more reliably.
  • a second filter is provided on the upper side of the cover so as to cover the hole, and the size of the mesh of the second filter is larger than the size of the mesh of the first filter. Good. Thus, it is possible to prevent dust from flowing into the suction filter when the valve is opened.
  • the second filter may be umbrella-shaped, and the lower end surface of the second filter may be in contact with the cover. This makes it possible to prevent the dust blocked by the second filtration unit from remaining on the second filtration unit.
  • a rod portion extending in the vertical direction and having a lower end near the cover may be provided, and the rod-shaped member may include a portion of the rod portion below the cover.
  • FIG. 1 It is a figure showing the outline of hydraulic oil tank 100 in which suction filter 1 which is one embodiment of the present invention was provided. It is a figure which shows the outline of the suction filter 1, (A) is a top view, (B) is sectional drawing in side view. It is sectional drawing which shows the outline of the suction filter 1, and is the figure which expanded and displayed a part. It is sectional drawing which shows the outline of the suction filter 1, and is the figure which expanded and displayed a part. 5 is a graph showing a relationship between a flow rate of hydraulic oil and a negative pressure in a space S1 when the valve 20 is not provided and when the valve 20 is provided.
  • FIG. 1 It is a figure which shows the outline of the suction filter 2
  • (A) is a top view
  • (B) is sectional drawing in side view. It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. It is sectional drawing which shows the outline of the suction filter 2A, and is the figure which expanded and displayed a part.
  • a suction filter provided inside a tank in which hydraulic oil is stored will be described as an example, but the liquid filtered by the suction filter is not limited to hydraulic oil.
  • FIG. 1 is a view schematically showing a hydraulic oil tank 100 in which a suction filter 1 according to one embodiment of the present invention is provided.
  • FIG. 1 shows a perspective view of a main part of the hydraulic oil tank 100. In FIG. 1, the flow of the hydraulic oil is indicated by broken lines.
  • the hydraulic oil tank 100 is installed in a working machine (for example, a hydraulic device) not shown, and is a tank for storing hydraulic oil provided in a hydraulic circuit of hydraulic oil supplied to the hydraulic device. is there.
  • the hydraulic oil tank 100 includes, for example, a box-shaped tank main body 101, and the inside of the tank main body 101 is hollow.
  • the suction filter 1 and the return filter 110 are mainly provided inside the tank main body 101.
  • hydraulic oil is introduced into the hydraulic oil tank 100 through a hydraulic device.
  • An inflow port 101 a through which hydraulic oil flows into the tank body 101 is formed on a side surface of the tank body 101.
  • the hydraulic oil flowing from the inflow port 101a is guided to the return filter 110.
  • the hydraulic oil is filtered by the return filter 110 and stored in the hydraulic oil tank 100.
  • An outflow portion 101 d that allows hydraulic oil in the tank main body 101 to flow out to the pump 111 is formed near the lower end of the tank main body 101 (in the present embodiment, at a position near the bottom surface on the side surface of the tank main body 101).
  • a suction pipe 104 connected to the suction port of the pump 111 is fitted into the outflow portion 101d from outside the tank body 101.
  • a suction filter 1 is provided above the outflow portion 101d (inside the tank body 101) to prevent foreign matter from entering the suction pipe 104.
  • the hydraulic oil stored in the hydraulic oil tank 100 is sucked by the pump 111, flows out to the suction pipe 104 through the suction filter 1, and is again supplied to the hydraulic device.
  • the suction filter 1 is provided with a center bolt 30 extending upward.
  • Male screw portions (not shown in FIG. 1) are formed on the lower end side and the upper end side of the center bolt 30, respectively.
  • the male screw portion 30a (see FIG. 2) on the lower end side of the center bolt 30 is screwed with a female screw portion (not shown) formed on the cover 15 (described in detail later) of the suction filter 1.
  • a nut 31 (see FIG. 2) is screwed into the male screw portion 30a so as to be in contact with the cover 15 of the suction filter 1.
  • openings 101b and 101c used for maintenance of the suction filter 1 and the return filter 110 are formed.
  • the lid 102 is attached to the opening 101b, and the lid 103 is attached to the opening 101c.
  • Bolt insertion holes are formed in the peripheral portions of the lids 102 and 103. By screwing a bolt 105 inserted through the bolt insertion hole into a bolt hole (not shown) of the tank main body 101, the lids 102 and 103 are fastened to the tank main body 101.
  • a male guide (not shown) having a bottom and a substantially cylindrical shape and having an open upper end is provided on the male screw portion on the upper end side of the center bolt 30, and an elastic member (not shown) is provided inside the guide.
  • the guide contacts the lower surface of the lid 103.
  • both ends of the elastic member come into contact with the lid 103 and the guide, and the elastic member urges the center bolt 30, that is, the suction filter 1 downward, so that the suction filter 1 is held inside the tank main body 101.
  • the outflow part 101d is not limited to the position shown in FIG. 1 as long as it is near the lower end of the tank body 101.
  • the outflow portion 101d may be provided on the bottom surface of the tank main body 101.
  • a partition plate 101f is provided on the bottom surface of the tank body 101 to divide the space in which the suction filter 1 is provided and the space in which the return filter 110 is provided. Note that the partition plate 101f is not essential.
  • FIG. 2 is a view schematically showing the suction filter 1, in which (A) is a plan view and (B) is a cross-sectional view in a side view.
  • the suction filter 1 mainly has a strainer section 10 and a valve 20.
  • the strainer section 10 is a substantially cylindrical member, and is placed above the outflow section 101d.
  • the strainer unit 10 mainly includes a first filtration unit 11, an inner cylinder 12, a lower plate 13, a seal member 14, a cover 15, and a second filtration unit 16.
  • the first filtration unit 11 is for filtering hydraulic oil.
  • the first filtration unit 11 is formed by bending a mesh-like thin plate (sheet) in which warp yarns and weft yarns intersect with each other in a pleated shape, connecting both ends of the thin plate, and rounding them into a cylindrical shape.
  • the first filtration unit 11 has a substantially cylindrical shape having a thickness in the radial direction.
  • a wire mesh of 80 to 150 mesh is used for the first filtration unit 11.
  • the mesh is the number of meshes (openings) within a range of 25.4 mm in each of the vertical and horizontal directions, and a smaller mesh value indicates a larger mesh.
  • the first filtration unit 11 is formed of a metal mesh (for example, stainless steel) in which fine wires are woven in a mesh shape, but using a filter paper such as a synthetic resin or paper. Is also good.
  • the inner cylinder 12 is a substantially hollow cylindrical member having openings at both ends, and is formed using a material having high corrosion resistance (for example, a metal or resin such as stainless steel or aluminum). In the inner cylinder 12, a hole through which hydraulic oil passes is formed in substantially the entire area.
  • a first filtration unit 11 is provided outside the inner cylinder 12. The height of the first filtration unit 11 is substantially the same as the height of the inner cylinder 12. However, the inner cylinder 12 is not essential.
  • a lower plate 13 is provided on the lower end surface (the end surface on the ⁇ z side) of the first filtration unit 11 and the inner cylinder 12.
  • the lower plate 13 is a substantially disk-shaped member, and is formed using resin or metal.
  • the lower plate 13 covers the entire lower side of the first filtration unit 11 and the inner cylinder 12.
  • the lower plate 13 is provided with an outlet 13a.
  • the outlet 13a is provided substantially at the center of the lower plate 13, and a cylindrical portion 101e provided above the outflow portion 101d is inserted.
  • a seal member 14 such as an O-ring is provided inside the outlet 13a. When the tubular portion 101e is inserted into the outlet 13a, the seal member 14 makes the tubular portion 101e and the outlet 13a liquid-tight. Hold. This prevents the hydraulic oil from entering the strainer section 10 from between the seal member 14 and the outflow section 101d.
  • a cover 15 is provided on the upper end surface (the end surface on the + z side) of the first filtration unit 11 and the inner cylinder 12.
  • the cover 15 is a substantially disk-shaped member, and is formed using resin or metal. The cover 15 covers the entire upper side of the first filtration unit 11 and the inner cylinder 12.
  • the lower plate 13 and the cover 15 cover the openings on both sides of the first filtration unit 11 and the inner cylinder 12.
  • the lower plate 13 and the cover 15 sandwich the first filtration unit 11 and the inner cylinder 12.
  • the hydraulic oil that has passed through the first filtration unit 11 flows into the hollow portion (space S1) of the inner cylinder 12, and flows out from the outlet 13a of the lower plate 13.
  • a hole 15a is provided substantially at the center of the cover 15.
  • the hole 15a has a space S1 that is an internal space of the suction filter 1 (a space formed by the first filtration unit 11, the inner cylinder 12, the lower plate 13, and the cover 15) and an outside of the suction filter 1 (here, the tank body).
  • the space 101 communicates with a space S2 (refer to FIG. 1) which is an internal space of the space 101.
  • the outer diameter ⁇ 1 of the hole 15a is substantially half of the outer diameter ⁇ 2 of the cover 15 (see FIG. 2A).
  • a hole (not shown) is formed substantially at the center of the cover 15, and a center bolt 30 is inserted into this hole.
  • the center bolt 30 is fixed to the cover 15 by a nut 31.
  • a valve 20 is provided below the cover 15 ( ⁇ z side) and in a hollow portion of the first filtration unit 11 and the inner cylinder 12 so as to cover the hole 15a.
  • the valve 20 will be described later in detail.
  • a second filtering unit 16 is provided on the upper side (+ z side) of the cover 15 so as to cover the hole 15a.
  • the second filtering section 16 is fixed to the center bolt 30 by a nut 32.
  • FIG. 2A the illustration of the second filtration unit 16 and the nut 32 is omitted.
  • the second filtration unit 16 is coarser than the first filtration unit 11 to prevent pressure loss. In other words, the size of the mesh of the second filtering unit 16 is larger than the size of the mesh of the first filtering unit 11. In the present embodiment, a 24-mesh wire mesh is used for the second filtration unit 16.
  • the second filtering portion 16 has an umbrella shape, and the substantially annular lower end surface 16a of the second filtering portion 16 is in contact with the cover 15. As a result, the dust caught by the second filtering unit 16 does not stay on the surface of the second filtering unit 16 but drops toward the cover 15.
  • FIGS. 3 and 4 are cross-sectional views schematically showing the suction filter 1 and partially enlarged views.
  • FIG. 3 shows a state in which the valve 20 is closed (closed state)
  • FIG. 4 shows a state in which the valve is opened (open state).
  • the illustration of the first filtration unit 11 is omitted.
  • the valve 20 mainly has a sleeve 21, a first valve body 22, and an elastic member 23.
  • the sleeve 21 is a rod-shaped member, and is inserted into the center bolt 30.
  • the sleeve 21 is held and positioned by the nuts 31 and 33. Thereby, the sleeve 21 is erected on the cover 15.
  • the rod-shaped member of the present invention includes a portion of the sleeve 21 and the center bolt 30 existing below the cover 15.
  • the sleeve 21 covers the male screw portion 30a of the center bolt 30, and enables the first valve body 22 to slide.
  • a flange 21a is provided at the lower end of the sleeve 21, a flange 21a is provided.
  • the first valve body 22 is provided on the sleeve 21 and is movable along the sleeve 21. Both ends of the elastic member 23 are provided on the first valve body 22 and the flange 21a, respectively, and push up the first valve body 22 toward the cover 15.
  • the first valve body 22 does not contact the lower end surface of the cover 15, so that the first valve body 22 does not close the hole 15a, and the hydraulic oil flows from the space S2 into the space S1 (see FIG. 4 white). See the pullout arrow).
  • the cavitation pressure is generally said to be about 10 to about 30 kPa (about 0.1 kgf / cm 2 to about 0.3 kgf / cm 2 ), in this embodiment, the set pressure is 0.05 kgf / cm 2 or 0.025 kgf / cm 2 .
  • the spring constant of the elastic member 23 By setting the spring constant of the elastic member 23 to an appropriate value, an arbitrary set pressure can be obtained.
  • a suction filter 1 is attached to a tank body 101 in which hydraulic oil is stored.
  • the center bolt 30 is held so that the lower plate 13 is located at the lower end, and the suction filter 1 is pushed down ( ⁇ z direction).
  • FIG. 5 is a graph showing the relationship between the flow rate of hydraulic oil and the negative pressure in the space S1 when the valve 20 is not provided and when the valve 20 is provided.
  • 0.05 kgf / cm 2 to set pressure an experiment was conducted using the valve 20 of the two types of 0.025kgf / cm 2.
  • the horizontal axis represents the flow rate of the hydraulic oil
  • the vertical axis represents the negative pressure in the space S1.
  • the occurrence of cavitation in the suction filter 1 can be prevented.
  • the occurrence of erosion in the pump can be prevented, and the life of the pump can be extended.
  • the valve 20 uses the elastic member 23, an appropriate set pressure can be obtained.
  • the umbrella-shaped second filtering portion 16 is provided above the hole 15a, but the shape of the second filtering portion is not limited to the umbrella shape.
  • a substantially plate-shaped wire net may be provided as the second filtering portion so as to cover the hole 15a.
  • valve 20 is provided near the lower end of the center bolt 30, but a rod-shaped member other than the center bolt 30 may be provided on the cover 15, and the valve 20 may be provided using the rod-shaped member.
  • valve 20 having the first valve body 22 is used, but the form of the valve is not limited to this.
  • the second embodiment of the present invention uses a valve further having a second valve body for bleeding air.
  • the suction filter 2 according to the second embodiment will be described.
  • the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
  • FIG. 6 is a view schematically showing the suction filter 2, in which (A) is a plan view and (B) is a cross-sectional view in a side view.
  • the suction filter 2 mainly has a strainer section 10A and a valve 20A.
  • the strainer unit 10A mainly includes a first filtration unit 11, an inner cylinder 12, a lower plate 13, a seal member 14, a cover 15A, and a second filtration unit 16.
  • the cover 15A has a substantially disk-shaped plate-like portion 15h and a protrusion 15i provided on the plate-like portion 15h.
  • the convex portion 15i has a substantially cylindrical shape, and protrudes upward (+ z direction) from the plate-like portion 15h, that is, protrudes to the opposite side to the first filtering portion 11.
  • the inside of the convex portion 15i is a cavity (space S3), and the wall surface of the cavity is an inner wall surface 15k.
  • the inner wall surface 15k also serves as a wall surface of a hole provided substantially at the center of the plate-shaped portion 15h, and the space S3 is open at the lower end surface of the cover 15A.
  • the protrusion 15i has an upper end surface 15j, and a hole 15a is provided in the upper end surface 15j.
  • the hole 15a communicates the space S3 with the space S2.
  • a hole (not shown) is formed substantially at the center of the upper end surface 15j, and a center bolt 30 is inserted into this hole.
  • the center bolt 30 is fixed to the upper end surface 15j by a nut 31.
  • a valve 20A is provided below the cover 15A ( ⁇ z side) and in a hollow portion of the first filtration unit 11 and the inner cylinder 12 so as to cover the hole 15a.
  • FIGS. 7, 8, and 9 are cross-sectional views schematically showing the suction filter 2, and are partially enlarged views. 7 to 9, illustration of the first filtration unit 11 is omitted.
  • the valve 20A mainly includes a sleeve 21, a first valve body 22A, an elastic member 23, and a second valve body 24.
  • the first valve body 22A is provided on the sleeve 21 and is movable along the sleeve 21.
  • the air mixed in the hydraulic oil has a set pressure lower than the cavitation pressure at which bubbles are generated, the first valve body 22A moves, and the valve 20 is switched between the open state and the closed state.
  • a plurality of air holes 22a are formed in the first valve body 22A.
  • a second valve body 24 is provided above the first valve body 22A.
  • the second valve body 24 is substantially plate-shaped, and is formed using a material that sinks in hydraulic oil.
  • the second valve body 24 is provided on the sleeve 21 and is movable along the sleeve 21.
  • FIG. 7 shows a state in which the valve 20A is closed (closed state).
  • the first valve body 22A contacts the lower end surface of the cover 15A so as to cover the space S3 which is a cavity in the convex portion 15i.
  • the second valve body 24 is provided between the first valve body 22A and the cover 15A. When the valve 20A is in the closed state, the second valve body 24 is in the convex portion 15i, that is, in the space S3. Is provided.
  • the second valve body 24 is located at a position covering the air hole 22a. Then, the suction filter 2 is mounted inside the tank main body 101 in a state where the air enters the suction filter 2.
  • the suction filter 2 is submerged in the hydraulic oil stored in the tank body 101, the air accumulates below the cover 15A, and the air accumulates below the cover 15A. Push up.
  • FIG. 8 shows an air-bleeding state in which the second valve body 24 has moved upward (+ z direction).
  • the second valve element 24 When the second valve element 24 is pushed up to a position not covering the air hole 22a, the initial air is discharged to the outside of the suction filter 2 through the air hole 22a and the hole 15a (see the two-dot chain line arrow in FIG. 8). reference).
  • the position, size, and shape of the air holes 22a are not limited to those shown in FIGS. However, in order to secure an air pressure that pushes up the second valve body 24, it is desirable that the diameter of the air hole 22a be approximately 5 mm to approximately 10 mm or more.
  • FIG. 9 shows a state in which the valve 20A is open (open state).
  • the first valve body 22A is turned into a sleeve against the urging force of the elastic member 23. It moves downward along 21. Since the second valve body 24 sinks in the hydraulic oil, the second valve body 24 moves downward together with the first valve body 22A.
  • the first valve body 22A is separated from the lower end surface of the cover 15A, the space S1 and the space S3 are communicated, and the valve 20A is opened.
  • the hydraulic oil flows from the space S2 into the spaces S1 and S3 via the hole 15a (see the white arrows in FIG. 9).
  • the occurrence of cavitation in the suction filter 2 can be prevented. Further, by using the valve 20A having the second valve body 24, the air in the suction filter 2 (the space S1) can be discharged to the space S2. Therefore, it is possible to prevent the air in the space S2 from flowing out to the pump by riding the flow of the hydraulic oil.
  • the first valve body 22A since the first valve body 22A has a substantially plate shape, air does not easily accumulate between the first valve body 22A and the inner cylinder 12. Therefore, the operation time of the suction filter 2 is prolonged, and even if air accumulates in the space S1, the air accumulates below the first valve body 22A and pushes up the second valve body 24 to remove air. It can be discharged to S2.
  • the cover 15A in which the plate-shaped portion 15h and the projection 15i are formed as one component is used.
  • the plate-shaped portion 15h and the projection 15i are formed as separate components, and the cover 15A is assembled by assembling these components. It may be.
  • FIG. 10 is a cross-sectional view schematically showing a suction filter 2A according to a modified example, and is a partially enlarged view.
  • the suction filter 2A uses a substantially plate-shaped cover 15 and a valve 20B.
  • the valve 20B mainly includes a sleeve 21, a first valve body 22B, an elastic member 23, and a second valve body 24.
  • the first valve body 22B is provided on the sleeve 21 and is movable along the sleeve 21.
  • the first valve body 22B has a substantially cylindrical shape with a bottom, and has a plurality of air holes 22a formed in the bottom surface.
  • the second valve body 24 is provided above the first valve body 22B, and is movable along the sleeve 21.
  • the first valve body 22B moves downward along the sleeve 21 against the urging force of the elastic member 23. As a result, the first valve body 22B separates from the lower end surface of the cover 15A, the space S1 and the space S3 communicate with each other, and the valve 20B is opened. When the air pushes up the second valve body 24 via the air hole 22a, the air in the space S1 is discharged to the space S2 through the space S3.
  • the suction filter 2A since air tends to accumulate inside the space S1, particularly between the first valve body 22B and the inner cylinder 12 (the area surrounded by the two-dot chain line in FIG. 10), the suction filter 2A It is preferable to use a cover 15A having a convex portion 15i and a valve 20A having a substantially plate-shaped first valve body 22A.
  • substantially is a concept that includes not only the case of exactly the same but also an error or a deformation that does not lose the identity.
  • substantially orthogonal is not limited to a strictly orthogonal case, and is a concept that includes, for example, an error of about several degrees.
  • the expression “perpendicular, parallel, coincidence, etc.” includes not only the case of strictly orthogonal, parallel, coincidence, etc., but also the case of approximately parallel, approximately orthogonal, approximately coincidence, etc.
  • near means that a region within a certain range (can be arbitrarily determined) near a reference position is included.
  • the term “near the end” is a concept indicating that it is a region in a certain range near the end, and may or may not include the end.

Abstract

Provided is a suction filter configured so that the occurrence of erosion in a pump can be prevented by preventing the occurrence of cavitation. A valve is provided below a cover provided on the upper end surface of a first filtration section and covering the entire upper side of the first filtration section, and the valve is positioned within the hollow section of the first filtration section. The valve has a first valve body which is movable along a bar-like member, and an elastic member which has opposite ends provided to the first valve body and the bar-like member and which pushes up the first valve body toward the cover. When pressure inside a space formed by the first filtration section, the cover, and a lower plate reaches a set pressure lower than a cavitation pressure at which air mixed in liquid becomes bubbles, a closed state in which a hole in the cover is closed by the first valve body and an open state in which the hole is not closed by the first valve body are switched between each other.

Description

サクションフィルタSuction filter
　本発明は、サクションフィルタに関する。 The present invention relates to a suction filter.
　特許文献１には、作動油タンク内に配置され、作動油タンク内の作動油を浄化するフィルタ部と、このフィルタ部に連結され、上方向に延設されるロッド部とを備えており、ロッド部の上端が作動油タンクの開口部を覆うカバー部分に保持されているサクションフィルタが開示されている。 Patent Literature 1 includes a filter portion that is disposed in a hydraulic oil tank and purifies hydraulic oil in the hydraulic oil tank, and a rod portion connected to the filter portion and extending upward, A suction filter in which an upper end of a rod portion is held by a cover portion that covers an opening of a hydraulic oil tank is disclosed.
特開２００２－０２１８０３号公報JP-A-2002-021803
　濾過装置の負圧が一定以上になると、液体の中に溶けていた空気が圧力の低下に伴って液の外に逃げ出し、液体の中に気泡が発生する（キャビテーション）。このキャビテーションは、液体の流動中に圧力の高いところへくると崩壊する。 (4) When the negative pressure of the filtration device exceeds a certain level, air dissolved in the liquid escapes out of the liquid as the pressure decreases, and bubbles are generated in the liquid (cavitation). This cavitation collapses when it comes to high pressure during the flow of the liquid.
　特許文献１に記載のサクションフィルタで濾過された後の作動油は、油圧ポンプに導かれる。しかしながら、特許文献１に記載の発明では、液体中のキャビテーションの発生を防止することができない。したがって、液体と共に気泡がポンプに導かれ、キャビテーションがポンプ内部で崩壊して高い衝撃が発生すると、ポンプ内部の固体表面上に壊食（エロージョン）と呼ばれる破壊現象を引き起し、ポンプの寿命を著しく低下させるという問題がある。 作 動 The hydraulic oil after being filtered by the suction filter described in Patent Document 1 is guided to a hydraulic pump. However, the invention described in Patent Document 1 cannot prevent cavitation in a liquid. Therefore, when air bubbles are guided to the pump together with the liquid, and cavitation collapses inside the pump and a high impact is generated, a phenomena called erosion (erosion) is caused on the solid surface inside the pump, thereby extending the life of the pump. There is a problem of remarkable reduction.
　本発明はこのような事情に鑑みてなされたもので、キャビテーションの発生を防止し、ポンプ内でのエロージョンの発生を防ぐことができるサクションフィルタを提供することを目的とする。 The present invention has been made in view of such circumstances, and has as its object to provide a suction filter capable of preventing occurrence of cavitation and occurrence of erosion in a pump.
　上記課題を解決するために、本発明に係るサクションフィルタは、例えば、油が貯留されるタンク内に設けられ、前記タンク内からポンプに吸入される液体を濾過するサクションフィルタであって、縦糸と横糸とを交差させた網目状の薄板をプリーツ状に折り曲げて形成した略筒状の第１濾過部と、前記第１濾過部の上端面に設けられ、前記第１濾過部の上側全体を覆うカバーと、前記第１濾過部の下端面に設けられ、前記第１濾過部の下側全体を覆う下プレートであって、前記液体を前記ポンプへ流出させる流出口を有する下プレートと、前記カバーの下側かつ前記第１濾過部の中空部に設けられたバルブと、を備え、前記カバーは、孔を有し、前記バルブは、前記カバーに立設された棒状部材と、前記棒状部材に設けられ、前記棒状部材に沿って移動可能な第１弁体と、両端が前記第１弁体及び前記棒状部材に設けられ、前記第１弁体を前記カバーに向けて押し上げる弾性部材と、を有し、前記バルブは、前記第１濾過部、前記カバー及び前記下プレートにより形成された空間の内部の圧力が前記液体中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、前記第１弁体が前記孔を塞ぐ閉状態と前記第１弁体が前記孔を塞がない開状態とを切り替えるように構成されていることを特徴とする。 In order to solve the above problems, a suction filter according to the present invention is, for example, a suction filter that is provided in a tank in which oil is stored, and that filters a liquid sucked into a pump from the tank, and includes a warp yarn. A substantially cylindrical first filtration unit formed by bending a mesh-like thin plate crossing a weft into a pleated shape, and provided on the upper end surface of the first filtration unit, covering the entire upper side of the first filtration unit. A cover, a lower plate provided on a lower end surface of the first filtration unit, and covering an entire lower side of the first filtration unit, the lower plate having an outlet through which the liquid flows out to the pump; And a valve provided in a hollow portion of the first filtration unit, wherein the cover has a hole, and the valve has a rod-shaped member erected on the cover and a rod-shaped member. The bar-shaped part provided And a resilient member provided at both ends of the first valve body and the rod-shaped member to push up the first valve body toward the cover. When the pressure inside the space formed by the first filtration unit, the cover, and the lower plate becomes a set pressure lower than the cavitation pressure at which air mixed in the liquid becomes bubbles, the first valve body Is configured to switch between a closed state in which the hole is closed and an open state in which the first valve body does not close the hole.
　本発明に係るサクションフィルタによれば、第１濾過部の上端面に設けられ、第１濾過部の上側全体を覆うカバーの下側かつ第１濾過部の中空部には、バルブが設けられている。バルブは、棒状部材に沿って移動可能な第１弁体と、両端が第１弁体及び棒状部材に設けられ、第１弁体をカバーに向けて押し上げる弾性部材と、を有する。第１濾過部、カバー及び下プレートにより形成された空間の内部の圧力が、液体中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、第１弁体がカバーの孔を塞ぐ閉状態と第１弁体が孔を塞がない開状態とを切り替える。これにより、キャビテーションの発生を防止し、ポンプ内でのエロージョンの発生を防ぐことができる。 According to the suction filter of the present invention, a valve is provided on the upper end surface of the first filtration unit, below the cover that covers the entire upper side of the first filtration unit, and in the hollow portion of the first filtration unit. I have. The valve has a first valve body movable along the rod-shaped member, and an elastic member provided at both ends of the first valve body and the rod-shaped member, and for pushing up the first valve body toward the cover. When the pressure inside the space formed by the first filtration unit, the cover, and the lower plate reaches a set pressure lower than the cavitation pressure at which air mixed into the liquid becomes bubbles, the first valve element closes the hole of the cover. The valve is switched between a closed state in which the hole is closed and an open state in which the first valve body does not block the hole. As a result, it is possible to prevent the occurrence of cavitation and the occurrence of erosion in the pump.
　ここで、前記第１弁体には空気孔が形成され、前記バルブは、前記棒状部材に設けられ、前記棒状部材に沿って移動可能な第２弁体を有し、前記第２弁体は、前記第１弁体と前記カバーとの間に設けられ、前記空気孔を覆う位置と前記空気孔を覆わない位置との間で移動可能であってもよい。これにより、サクションフィルタ内の空気を排出することができる。 Here, an air hole is formed in the first valve body, and the valve has a second valve body provided on the rod-shaped member and movable along the rod-shaped member. , May be provided between the first valve body and the cover, and may be movable between a position covering the air hole and a position not covering the air hole. Thereby, the air in the suction filter can be discharged.
　ここで、前記カバーは、板状部と、前記板状部に設けられ、前記第１濾過部と反対側に突出する凸部を有し、前記凸部は、内部が空洞であり、前記空洞は前記カバーの下端面に開口しており、前記バルブが前記閉状態のときに、前記第１弁体は前記空洞を覆うように前記カバーの下端面に当接し、前記第２弁体は前記空洞の内部に設けられてもよい。これにより、サクションフィルタの内部に空気が溜まりにくく、サクションフィルタ内の空気をより確実に排出することができる。 Here, the cover has a plate-shaped portion, and a protrusion provided on the plate-shaped portion and protruding on a side opposite to the first filtering portion. Is open at the lower end surface of the cover, and when the valve is in the closed state, the first valve body contacts the lower end surface of the cover so as to cover the cavity, and the second valve body is It may be provided inside the cavity. This makes it difficult for air to accumulate inside the suction filter, and allows the air in the suction filter to be discharged more reliably.
　ここで、前記カバーの上側に、前記孔を覆うように設けられた第２濾過部を備え、前記第２濾過部の網目の大きさは、前記第１濾過部の網目の大きさより大きくてもよい。これにより、バルブが開いたときに塵埃がサクションフィルタの内部に流入しないようにすることができる。 Here, a second filter is provided on the upper side of the cover so as to cover the hole, and the size of the mesh of the second filter is larger than the size of the mesh of the first filter. Good. Thus, it is possible to prevent dust from flowing into the suction filter when the valve is opened.
　ここで、前記第２濾過部は傘状であり、前記第２濾過部の略円環形状の下端面が前記カバーと当接してもよい。これにより、第２濾過部にさえぎられた塵埃が第２濾過部上に留まらないようにすることができる。 Here, the second filter may be umbrella-shaped, and the lower end surface of the second filter may be in contact with the cover. This makes it possible to prevent the dust blocked by the second filtration unit from remaining on the second filtration unit.
　ここで、鉛直方向に延在し、下端近傍が前記カバーに設けられたロッド部を備え、前記棒状部材は、前記ロッド部の前記カバーの下側に存在する部分を含んでもよい。これにより、部品点数を減らし、簡単な構造とすることができる。 Here, a rod portion extending in the vertical direction and having a lower end near the cover may be provided, and the rod-shaped member may include a portion of the rod portion below the cover. Thereby, the number of parts can be reduced and a simple structure can be achieved.
　本発明によれば、キャビテーションの発生を防止し、ポンプ内でのエロージョンの発生を防ぐことができる。 According to the present invention, it is possible to prevent the occurrence of cavitation and the occurrence of erosion in the pump.
本発明の一実施形態であるサクションフィルタ１が内部に設けられた作動油タンク１００の概略を示す図である。It is a figure showing the outline of hydraulic oil tank 100 in which suction filter 1 which is one embodiment of the present invention was provided. サクションフィルタ１の概略を示す図であり、（Ａ）は平面図、（Ｂ）は側面視における断面図である。It is a figure which shows the outline of the suction filter 1, (A) is a top view, (B) is sectional drawing in side view. サクションフィルタ１の概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 1, and is the figure which expanded and displayed a part. サクションフィルタ１の概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 1, and is the figure which expanded and displayed a part. バルブ２０が設けられていない場合及びバルブ２０が設けられている場合の作動油の流量と空間Ｓ１の負圧との関係を示すグラフである。5 is a graph showing a relationship between a flow rate of hydraulic oil and a negative pressure in a space S1 when the valve 20 is not provided and when the valve 20 is provided. サクションフィルタ２の概略を示す図であり、（Ａ）は平面図、（Ｂ）は側面視における断面図である。It is a figure which shows the outline of the suction filter 2, (A) is a top view, (B) is sectional drawing in side view. サクションフィルタ２の概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. サクションフィルタ２の概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. サクションフィルタ２の概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 2, and is the figure which expanded and displayed a part. サクションフィルタ２Ａの概略を示す断面図であり、一部を拡大表示した図である。It is sectional drawing which shows the outline of the suction filter 2A, and is the figure which expanded and displayed a part.
　以下、本発明の実施形態を、図面を参照して詳細に説明する。以下、作動油が貯留されるタンクの内部に設けられるサクションフィルタを例に説明するが、サクションフィルタが濾過する液体は作動油に限られない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a suction filter provided inside a tank in which hydraulic oil is stored will be described as an example, but the liquid filtered by the suction filter is not limited to hydraulic oil.
＜第１の実施の形態＞
　図１は、本発明の一実施形態であるサクションフィルタ１が内部に設けられた作動油タンク１００の概略を示す図である。図１では、作動油タンク１００の要部を透視して図示している。図１では、作動油の流れを破線で示す。 <First embodiment>
FIG. 1 is a view schematically showing a hydraulic oil tank 100 in which a suction filter 1 according to one embodiment of the present invention is provided. FIG. 1 shows a perspective view of a main part of the hydraulic oil tank 100. In FIG. 1, the flow of the hydraulic oil is indicated by broken lines.
　作動油タンク１００は、図示しない作業機械（例えば、油圧装置）に設置されるものであり、この油圧装置へ供給する作動油の油圧回路内に設けられた、作動油を貯留するためのタンクである。作動油タンク１００は、例えば箱形のタンク本体１０１を備えており、このタンク本体１０１はその内部が空洞となっている。タンク本体１０１の内側には、主として、サクションフィルタ１と、リターンフィルタ１１０と、が設けられる。 The hydraulic oil tank 100 is installed in a working machine (for example, a hydraulic device) not shown, and is a tank for storing hydraulic oil provided in a hydraulic circuit of hydraulic oil supplied to the hydraulic device. is there. The hydraulic oil tank 100 includes, for example, a box-shaped tank main body 101, and the inside of the tank main body 101 is hollow. The suction filter 1 and the return filter 110 are mainly provided inside the tank main body 101.
　油圧回路において、作動油は、油圧装置を通って作動油タンク１００へ導入される。タンク本体１０１の側面には、作動油をタンク本体１０１の内部へ流入させる流入口１０１ａが形成される。流入口１０１ａから流入した作動油は、リターンフィルタ１１０に導かれる。作動油は、リターンフィルタ１１０により濾過されて、作動油タンク１００内に貯留される。 に お い て In the hydraulic circuit, hydraulic oil is introduced into the hydraulic oil tank 100 through a hydraulic device. An inflow port 101 a through which hydraulic oil flows into the tank body 101 is formed on a side surface of the tank body 101. The hydraulic oil flowing from the inflow port 101a is guided to the return filter 110. The hydraulic oil is filtered by the return filter 110 and stored in the hydraulic oil tank 100.
　タンク本体１０１の下端部近傍（本実施の形態では、タンク本体１０１の側面の、底面に近い位置）には、タンク本体１０１内の作動油をポンプ１１１へ流出させる流出部１０１ｄが形成される。流出部１０１ｄには、タンク本体１０１の外側から、ポンプ１１１の吸い込みポートへ繋がるサクションパイプ１０４が嵌挿されている。 流出 An outflow portion 101 d that allows hydraulic oil in the tank main body 101 to flow out to the pump 111 is formed near the lower end of the tank main body 101 (in the present embodiment, at a position near the bottom surface on the side surface of the tank main body 101). A suction pipe 104 connected to the suction port of the pump 111 is fitted into the outflow portion 101d from outside the tank body 101.
　流出部１０１ｄの上側（タンク本体１０１の内側）には、サクションパイプ１０４への異物の進入を防ぐため、サクションフィルタ１が設けられる。作動油タンク１００内に貯留された作動油は、ポンプ１１１に吸引されて、サクションフィルタ１を通ってサクションパイプ１０４へ流出し、再度油圧装置へ供給される。 サ A suction filter 1 is provided above the outflow portion 101d (inside the tank body 101) to prevent foreign matter from entering the suction pipe 104. The hydraulic oil stored in the hydraulic oil tank 100 is sucked by the pump 111, flows out to the suction pipe 104 through the suction filter 1, and is again supplied to the hydraulic device.
　サクションフィルタ１には、上方向に延設されるセンタボルト３０が設けられる。センタボルト３０の下端部側及び上端部側には、それぞれ雄ネジ部（図１では図示省略）が形成されている。センタボルト３０の下端部側の雄ネジ部３０ａ（図２参照）は、サクションフィルタ１のカバー１５（後に詳述）に形成された雌ネジ部（図示省略）と螺合している。また、サクションフィルタ１のカバー１５に接するように雄ネジ部３０ａにはナット３１（図２参照）が螺合している。 The suction filter 1 is provided with a center bolt 30 extending upward. Male screw portions (not shown in FIG. 1) are formed on the lower end side and the upper end side of the center bolt 30, respectively. The male screw portion 30a (see FIG. 2) on the lower end side of the center bolt 30 is screwed with a female screw portion (not shown) formed on the cover 15 (described in detail later) of the suction filter 1. A nut 31 (see FIG. 2) is screwed into the male screw portion 30a so as to be in contact with the cover 15 of the suction filter 1.
　また、タンク本体１０１の上端部には、サクションフィルタ１やリターンフィルタ１１０のメンテナンス等に利用する開口部１０１ｂ、１０１ｃが形成される。開口部１０１ｂには、蓋体１０２が取り付けられ、開口部１０１ｃには、蓋体１０３が取り付けられる。 {Circle around (2)} At the upper end of the tank body 101, openings 101b and 101c used for maintenance of the suction filter 1 and the return filter 110 are formed. The lid 102 is attached to the opening 101b, and the lid 103 is attached to the opening 101c.
　蓋体１０２、１０３の周縁部には、ボルト挿通孔が形成される。ボルト挿通孔に挿通されたボルト１０５をタンク本体１０１のボルト孔（図示せず）に螺合することにより、蓋体１０２、１０３はタンク本体１０１に締結される。 ボ ル ト Bolt insertion holes are formed in the peripheral portions of the lids 102 and 103. By screwing a bolt 105 inserted through the bolt insertion hole into a bolt hole (not shown) of the tank main body 101, the lids 102 and 103 are fastened to the tank main body 101.
　一方、センタボルト３０の上端部側の雄ネジ部には、上側に開口した有底略筒形状のガイド（図示省略）が設けられ、ガイドの内部には弾性部材（図示省略）が設けられている。ガイドは、蓋体１０３の下面に当接する。この結果、弾性部材の両端が蓋体１０３とガイドとに当接し、弾性部材がセンタボルト３０、すなわちサクションフィルタ１を下向きに付勢し、サクションフィルタ１がタンク本体１０１の内部に保持される。蓋体１０３をタンク本体１０１から取り外し、センタボルト３０の上端部を引っ張ることで、メンテナンス時等にサクションフィルタ１をタンク本体１０１から取り出すことができる。 On the other hand, a male guide (not shown) having a bottom and a substantially cylindrical shape and having an open upper end is provided on the male screw portion on the upper end side of the center bolt 30, and an elastic member (not shown) is provided inside the guide. I have. The guide contacts the lower surface of the lid 103. As a result, both ends of the elastic member come into contact with the lid 103 and the guide, and the elastic member urges the center bolt 30, that is, the suction filter 1 downward, so that the suction filter 1 is held inside the tank main body 101. By removing the lid 103 from the tank body 101 and pulling the upper end of the center bolt 30, the suction filter 1 can be taken out of the tank body 101 during maintenance or the like.
　なお、流出部１０１ｄは、タンク本体１０１の下端部近傍であれば、図１に示す位置に限定されない。例えば、流出部１０１ｄをタンク本体１０１の底面に設けてもよい。 The outflow part 101d is not limited to the position shown in FIG. 1 as long as it is near the lower end of the tank body 101. For example, the outflow portion 101d may be provided on the bottom surface of the tank main body 101.
　タンク本体１０１の底面には、サクションフィルタ１が設けられる空間と、リターンフィルタ１１０が設けられる空間と、を分割する仕切板１０１ｆが設けられる。なお、仕切板１０１ｆは必須ではない。 A partition plate 101f is provided on the bottom surface of the tank body 101 to divide the space in which the suction filter 1 is provided and the space in which the return filter 110 is provided. Note that the partition plate 101f is not essential.
　図２は、サクションフィルタ１の概略を示す図であり、（Ａ）は平面図、（Ｂ）は側面視における断面図である。図２（Ａ）では、説明のため、カバー１５の一部を切断している。サクションフィルタ１は、主として、ストレーナ部１０と、バルブ２０とを有する。 FIG. 2 is a view schematically showing the suction filter 1, in which (A) is a plan view and (B) is a cross-sectional view in a side view. In FIG. 2 (A), a part of the cover 15 is cut for explanation. The suction filter 1 mainly has a strainer section 10 and a valve 20.
　ストレーナ部１０は、略円筒形状の部材であり、流出部１０１ｄの上側に載置される。ストレーナ部１０は、主として、第１濾過部１１と、内筒１２と、下プレート１３、シール部材１４と、カバー１５と、第２濾過部１６と、を有する。 The strainer section 10 is a substantially cylindrical member, and is placed above the outflow section 101d. The strainer unit 10 mainly includes a first filtration unit 11, an inner cylinder 12, a lower plate 13, a seal member 14, a cover 15, and a second filtration unit 16.
　第１濾過部１１は作動油を濾過するためのものである。第１濾過部１１は、縦糸と横糸とを交差させた網目状の薄板（シート）をプリーツ状に折り曲げ、薄板の両端を連結して円筒状に丸めることによって形成される。これにより、第１濾過部１１は、径方向に厚みを有する略円筒形状となる。本実施の形態では、第１濾過部１１には８０～１５０メッシュの金網を用いる。ここでメッシュとは、縦、横各２５．４ｍｍの範囲内にある網目（開口）の数であり、メッシュの値が小さいほど網目が大きいことを示す。 The first filtration unit 11 is for filtering hydraulic oil. The first filtration unit 11 is formed by bending a mesh-like thin plate (sheet) in which warp yarns and weft yarns intersect with each other in a pleated shape, connecting both ends of the thin plate, and rounding them into a cylindrical shape. Thereby, the first filtration unit 11 has a substantially cylindrical shape having a thickness in the radial direction. In the present embodiment, a wire mesh of 80 to 150 mesh is used for the first filtration unit 11. Here, the mesh is the number of meshes (openings) within a range of 25.4 mm in each of the vertical and horizontal directions, and a smaller mesh value indicates a larger mesh.
　なお、本実施の形態では、第１濾過部１１は、細線がメッシュ状に編みこまれた金属（例えば、ステンレス）製の金網により形成されているが、合成樹脂や紙等のろ紙を用いてもよい。 In the present embodiment, the first filtration unit 11 is formed of a metal mesh (for example, stainless steel) in which fine wires are woven in a mesh shape, but using a filter paper such as a synthetic resin or paper. Is also good.
　内筒１２は、両端に開口を有する略中空円筒形状の部材であり、耐腐食性の高い材料（例えば、ステンレス、アルミニウム等の金属や樹脂）を用いて形成される。内筒１２には、略全域に作動油が通過する孔が形成されている。内筒１２の外側には、第１濾過部１１が設けられる。第１濾過部１１の高さは、内筒１２の高さと略同じである。ただし、内筒１２は必須ではない。 The inner cylinder 12 is a substantially hollow cylindrical member having openings at both ends, and is formed using a material having high corrosion resistance (for example, a metal or resin such as stainless steel or aluminum). In the inner cylinder 12, a hole through which hydraulic oil passes is formed in substantially the entire area. A first filtration unit 11 is provided outside the inner cylinder 12. The height of the first filtration unit 11 is substantially the same as the height of the inner cylinder 12. However, the inner cylinder 12 is not essential.
　第１濾過部１１及び内筒１２の下端面（－ｚ側の端面）には下プレート１３が設けられる。下プレート１３は、略円板状の部材であり、樹脂又は金属を用いて形成される。下プレート１３は、第１濾過部１１及び内筒１２の下側全体を覆う。下プレート１３には、流出口１３ａが設けられる。流出口１３ａは、下プレート１３の略中央に設けられており、流出部１０１ｄの上側に設けられた筒状部１０１ｅが挿入される。流出口１３ａの内側にはＯリング等のシール部材１４が設けられており、筒状部１０１ｅが流出口１３ａに挿入されるとシール部材１４が筒状部１０１ｅと流出口１３ａとを液密に保持する。これにより、シール部材１４と流出部１０１ｄとの間から、作動油がストレーナ部１０内へ浸入するのが防止される。 下 A lower plate 13 is provided on the lower end surface (the end surface on the −z side) of the first filtration unit 11 and the inner cylinder 12. The lower plate 13 is a substantially disk-shaped member, and is formed using resin or metal. The lower plate 13 covers the entire lower side of the first filtration unit 11 and the inner cylinder 12. The lower plate 13 is provided with an outlet 13a. The outlet 13a is provided substantially at the center of the lower plate 13, and a cylindrical portion 101e provided above the outflow portion 101d is inserted. A seal member 14 such as an O-ring is provided inside the outlet 13a. When the tubular portion 101e is inserted into the outlet 13a, the seal member 14 makes the tubular portion 101e and the outlet 13a liquid-tight. Hold. This prevents the hydraulic oil from entering the strainer section 10 from between the seal member 14 and the outflow section 101d.
　第１濾過部１１及び内筒１２の上端面（＋ｚ側の端面）にはカバー１５が設けられる。カバー１５は、略円板状の部材であり、樹脂又は金属を用いて形成される。カバー１５は、第１濾過部１１及び内筒１２の上側全体を覆う。 カ バ ー A cover 15 is provided on the upper end surface (the end surface on the + z side) of the first filtration unit 11 and the inner cylinder 12. The cover 15 is a substantially disk-shaped member, and is formed using resin or metal. The cover 15 covers the entire upper side of the first filtration unit 11 and the inner cylinder 12.
　このように、下プレート１３及びカバー１５は、第１濾過部１１、内筒１２の両側の開口を覆う。言い換えると、下プレート１３及びカバー１５は、第１濾過部１１及び内筒１２を挟持する。これにより、第１濾過部１１を通過した作動油は、内筒１２の中空部（空間Ｓ１）に流れ込み、下プレート１３の流出口１３ａから流出する。 Thus, the lower plate 13 and the cover 15 cover the openings on both sides of the first filtration unit 11 and the inner cylinder 12. In other words, the lower plate 13 and the cover 15 sandwich the first filtration unit 11 and the inner cylinder 12. Thereby, the hydraulic oil that has passed through the first filtration unit 11 flows into the hollow portion (space S1) of the inner cylinder 12, and flows out from the outlet 13a of the lower plate 13.
　カバー１５の略中央には、孔１５ａが設けられている。孔１５ａは、サクションフィルタ１の内部空間（第１濾過部１１、内筒１２、下プレート１３及びカバー１５により形成された空間）である空間Ｓ１と、サクションフィルタ１の外部（ここでは、タンク本体１０１の内部空間である空間Ｓ２（図１参照））とを連通する。バルブ２０のオーバーライド特性を小さくするため、孔１５ａをできるだけ大きくすることが望ましい。本実施の形態では、孔１５ａの外径φ１は、カバー１５の外径φ２の略半分である（図２（Ａ）参照）。 孔 A hole 15a is provided substantially at the center of the cover 15. The hole 15a has a space S1 that is an internal space of the suction filter 1 (a space formed by the first filtration unit 11, the inner cylinder 12, the lower plate 13, and the cover 15) and an outside of the suction filter 1 (here, the tank body). The space 101 communicates with a space S2 (refer to FIG. 1) which is an internal space of the space 101. In order to reduce the override characteristic of the valve 20, it is desirable to make the hole 15a as large as possible. In the present embodiment, the outer diameter φ1 of the hole 15a is substantially half of the outer diameter φ2 of the cover 15 (see FIG. 2A).
　また、カバー１５の略中央には孔（図示省略）が形成されており、この孔にはセンタボルト３０が挿入されている。センタボルト３０は、ナット３１によりカバー１５に固定されている。 A hole (not shown) is formed substantially at the center of the cover 15, and a center bolt 30 is inserted into this hole. The center bolt 30 is fixed to the cover 15 by a nut 31.
　カバー１５の下側（－ｚ側）かつ第１濾過部１１及び内筒１２の中空部には、孔１５ａを覆うようにバルブ２０が設けられている。バルブ２０については後に詳述する。 バ ル ブ A valve 20 is provided below the cover 15 (−z side) and in a hollow portion of the first filtration unit 11 and the inner cylinder 12 so as to cover the hole 15a. The valve 20 will be described later in detail.
　カバー１５の上側（＋ｚ側）には、孔１５ａを覆うように第２濾過部１６が設けられている。第２濾過部１６は、ナット３２によりセンタボルト３０に固定されている。なお、図２（Ａ）では第２濾過部１６及びナット３２の図示を省略している。 A second filtering unit 16 is provided on the upper side (+ z side) of the cover 15 so as to cover the hole 15a. The second filtering section 16 is fixed to the center bolt 30 by a nut 32. In FIG. 2A, the illustration of the second filtration unit 16 and the nut 32 is omitted.
　圧力損失を防ぐため、第２濾過部１６は、第１濾過部１１より目が粗い。言い換えれば、第２濾過部１６の網目の大きさは、第１濾過部１１の網目の大きさより大きい。本実施の形態では、第２濾過部１６には２４メッシュの金網を用いる。 ２The second filtration unit 16 is coarser than the first filtration unit 11 to prevent pressure loss. In other words, the size of the mesh of the second filtering unit 16 is larger than the size of the mesh of the first filtering unit 11. In the present embodiment, a 24-mesh wire mesh is used for the second filtration unit 16.
　第２濾過部１６は傘状であり、第２濾過部１６の略円環形状の下端面１６ａがカバー１５と当接する。これにより、第２濾過部１６で捕らえられた塵埃が第２濾過部１６の表面にとどまらず、カバー１５に向けて落下する。 ２The second filtering portion 16 has an umbrella shape, and the substantially annular lower end surface 16a of the second filtering portion 16 is in contact with the cover 15. As a result, the dust caught by the second filtering unit 16 does not stay on the surface of the second filtering unit 16 but drops toward the cover 15.
　図３、４は、サクションフィルタ１の概略を示す断面図であり、一部を拡大表示した図である。図３は、バルブ２０が閉じた状態（閉状態）を示し、図４はバルブが開いた状態（開状態）を示す。図３では、第１濾過部１１の図示を省略している。バルブ２０は、主として、スリーブ２１と、第１弁体２２と、弾性部材２３と、を有する。 FIGS. 3 and 4 are cross-sectional views schematically showing the suction filter 1 and partially enlarged views. FIG. 3 shows a state in which the valve 20 is closed (closed state), and FIG. 4 shows a state in which the valve is opened (open state). In FIG. 3, the illustration of the first filtration unit 11 is omitted. The valve 20 mainly has a sleeve 21, a first valve body 22, and an elastic member 23.
　スリーブ２１は、棒状の部材であり、センタボルト３０に挿入される。スリーブ２１は、ナット３１、３３により狭持され、位置決めされる。これにより、スリーブ２１がカバー１５に立設される。スリーブ２１及びセンタボルト３０のカバー１５の下側に存在する部分を含めて本発明の棒状部材となる。スリーブ２１は、センタボルト３０の雄ネジ部３０ａを覆い、第１弁体２２を摺動可能とする。スリーブ２１の下端には、フランジ２１ａが設けられる。 The sleeve 21 is a rod-shaped member, and is inserted into the center bolt 30. The sleeve 21 is held and positioned by the nuts 31 and 33. Thereby, the sleeve 21 is erected on the cover 15. The rod-shaped member of the present invention includes a portion of the sleeve 21 and the center bolt 30 existing below the cover 15. The sleeve 21 covers the male screw portion 30a of the center bolt 30, and enables the first valve body 22 to slide. At the lower end of the sleeve 21, a flange 21a is provided.
　第１弁体２２は、スリーブ２１に設けられており、スリーブ２１に沿って移動可能である。弾性部材２３は、両端がそれぞれ第１弁体２２とフランジ２１ａに設けられ、第１弁体２２をカバー１５に向けて押し上げる。 The first valve body 22 is provided on the sleeve 21 and is movable along the sleeve 21. Both ends of the elastic member 23 are provided on the first valve body 22 and the flange 21a, respectively, and push up the first valve body 22 toward the cover 15.
　作動油中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、第１弁体２２が移動し、バルブ２０の開状態と閉状態とが切り替えられる。通常、バルブ２０は図３に示す閉状態にある。閉状態では、第１弁体２２がカバー１５の下端面に当接し、第１弁体２２が孔１５ａを塞いでいる。空間Ｓ１の内部の負圧が大きくなると、弾性部材２３の付勢力に抗して第１弁体２２がスリーブ２１に沿って下方向（－ｚ方向）に移動し、バルブ２０が図４に示す開状態になる。開状態では、第１弁体２２がカバー１５の下端面に当接しないため、第１弁体２２が孔１５ａを塞がず、作動油が空間Ｓ２から空間Ｓ１へと流入する（図４白抜き矢印参照）。 (4) When the air mixed in the hydraulic oil has a set pressure lower than the cavitation pressure at which bubbles are generated, the first valve body 22 moves, and the valve 20 is switched between the open state and the closed state. Normally, the valve 20 is in the closed state shown in FIG. In the closed state, the first valve body 22 is in contact with the lower end surface of the cover 15, and the first valve body 22 closes the hole 15a. When the negative pressure inside the space S1 increases, the first valve body 22 moves downward (-z direction) along the sleeve 21 against the urging force of the elastic member 23, and the valve 20 is shown in FIG. Become open. In the open state, the first valve body 22 does not contact the lower end surface of the cover 15, so that the first valve body 22 does not close the hole 15a, and the hydraulic oil flows from the space S2 into the space S1 (see FIG. 4 white). See the pullout arrow).
　キャビテーション圧力は、一般的に略１０～略３０ｋＰａ（略０．１ｋｇｆ／ｃｍ２～略０．３ｋｇｆ／ｃｍ２）といわれているため、本実施の形態ではセット圧を０．０５ｋｇｆ／ｃｍ２又は０．０２５ｋｇｆ／ｃｍ２とする。弾性部材２３のばね定数を適切な値とすることで、任意のセット圧とすることができる。 Since the cavitation pressure is generally said to be about 10 to about 30 kPa (about 0.1 kgf / cm 2 to about 0.3 kgf / cm 2 ), in this embodiment, the set pressure is 0.05 kgf / cm 2 or 0.025 kgf / cm 2 . By setting the spring constant of the elastic member 23 to an appropriate value, an arbitrary set pressure can be obtained.
　次に、このように構成されたサクションフィルタ１の機能について説明する。まず、図１に示すように、作動油が貯蔵されたタンク本体１０１に、サクションフィルタ１を取り付ける。下プレート１３が下端に位置するようにセンタボルト３０を保持し、サクションフィルタ１を下方（－ｚ方向）へ押し下げる。 Next, the function of the suction filter 1 configured as described above will be described. First, as shown in FIG. 1, a suction filter 1 is attached to a tank body 101 in which hydraulic oil is stored. The center bolt 30 is held so that the lower plate 13 is located at the lower end, and the suction filter 1 is pushed down (−z direction).
　タンク本体１０１に貯蔵された作動油は、ポンプ１１１に吸引されると、第１濾過部１１の外側から、内筒１２の内部へ吸い込まれる。内筒１２の内部へ流出した油は、下方からサクションフィルタ１の外へ流出する。 (4) When the hydraulic oil stored in the tank body 101 is sucked by the pump 111, it is sucked into the inner cylinder 12 from outside the first filtration unit 11. The oil that has flowed into the inner cylinder 12 flows out of the suction filter 1 from below.
　作動油の流量が増加すると、空間Ｓ１の負圧が大きくなる。そして、負圧がセット圧となると、第１弁体２２が移動し、閉状態にあったバルブ２０が開状態になる。 (4) When the flow rate of the hydraulic oil increases, the negative pressure in the space S1 increases. Then, when the negative pressure becomes the set pressure, the first valve body 22 moves, and the valve 20 that has been closed is opened.
　図５は、バルブ２０が設けられていない場合及びバルブ２０が設けられている場合の作動油の流量と空間Ｓ１の負圧との関係を示すグラフである。ここでは、セット圧を０．０５ｋｇｆ／ｃｍ２、０．０２５ｋｇｆ／ｃｍ２の２通りのバルブ２０を用いて実験を行った。図５において、横軸は作動油の流量であり、縦軸は空間Ｓ１の負圧である。 FIG. 5 is a graph showing the relationship between the flow rate of hydraulic oil and the negative pressure in the space S1 when the valve 20 is not provided and when the valve 20 is provided. Here, 0.05 kgf / cm 2 to set pressure, an experiment was conducted using the valve 20 of the two types of 0.025kgf / cm 2. In FIG. 5, the horizontal axis represents the flow rate of the hydraulic oil, and the vertical axis represents the negative pressure in the space S1.
　図５に示すように、バルブ２０が設けられていない場合には、作動油の流量の増加と共に空間Ｓ１の負圧が上昇し、０．０８ｋｇｆ／ｃｍ２でキャビテーションが発生してしまった。そして、キャビテーション発生後も作動油の流量の増加と共に空間Ｓ１の負圧が上昇した。 As shown in FIG. 5, when the valve 20 was not provided, the negative pressure in the space S1 increased with an increase in the flow rate of the hydraulic oil, and cavitation occurred at 0.08 kgf / cm 2 . Then, even after the occurrence of cavitation, the negative pressure in the space S1 increased with an increase in the flow rate of the hydraulic oil.
　それに対し、バルブ２０を設けた場合には、作動油の流量の増加と共に空間Ｓ１の負圧が上昇したが、空間Ｓ１の負圧はセット圧より大きくならず、キャビテーションは発生しなかった。 In contrast, when the valve 20 was provided, the negative pressure in the space S1 increased with an increase in the flow rate of the hydraulic oil, but the negative pressure in the space S1 did not become larger than the set pressure, and no cavitation occurred.
　図４に示すように、バルブ２０が開くと、孔１５ａを介して未濾過の作動油が空間Ｓ２から空間Ｓ１に流入する。第２濾過部１６が設けられていることで、大きな塵埃が空間Ｓ１に流入しないようにすることができる。 と As shown in FIG. 4, when the valve 20 is opened, the unfiltered hydraulic oil flows from the space S2 into the space S1 through the hole 15a. The provision of the second filtering unit 16 can prevent large dust from flowing into the space S1.
　本実施の形態によれば、サクションフィルタ１でのキャビテーションの発生を防止することができる。その結果、ポンプ内でのエロージョンの発生を防ぎ、ポンプの長寿命化に寄与することができる。また、弾性部材２３を用いたバルブ２０としたため、適切なセット圧にすることができる。 According to the present embodiment, the occurrence of cavitation in the suction filter 1 can be prevented. As a result, the occurrence of erosion in the pump can be prevented, and the life of the pump can be extended. Further, since the valve 20 uses the elastic member 23, an appropriate set pressure can be obtained.
　例えば、通常はフロートが油に浮いて孔１５ａを覆い、負圧が大きくなるとフロートが下がって孔１５ａが解放されるボール弁を採用する場合には、空間Ｓ１の負圧が小さい状態でバルブが開いてしまうという問題がある。その結果、必要以上に早い段階で未濾過の作動油が空間Ｓ１に流入し、サクションフィルタ１の役割が果たせなくなってしまう。それに対し、弾性部材２３を用いて第１弁体２２を移動させるバルブ２０とすることで、セット圧を適切な値とし、キャビテーションを防ぎつつサクションフィルタ１の役割を果たすことができる。 For example, when adopting a ball valve in which the float normally floats on the oil and covers the hole 15a, and when the negative pressure increases, the float lowers and the hole 15a is released, the valve is operated in a state where the negative pressure in the space S1 is small. There is a problem of opening. As a result, unfiltered hydraulic oil flows into the space S1 at an earlier stage than necessary, and the role of the suction filter 1 cannot be fulfilled. On the other hand, by using the valve 20 that moves the first valve body 22 using the elastic member 23, the set pressure can be set to an appropriate value, and the function of the suction filter 1 can be achieved while preventing cavitation.
　なお、本実施の形態では、孔１５ａの上側に傘型の第２濾過部１６を設けたが、第２濾過部の形状は傘型に限られない。例えば、略板状の金網を第２濾過部として孔１５ａを覆うように設けてもよい。 In the present embodiment, the umbrella-shaped second filtering portion 16 is provided above the hole 15a, but the shape of the second filtering portion is not limited to the umbrella shape. For example, a substantially plate-shaped wire net may be provided as the second filtering portion so as to cover the hole 15a.
　また、本実施の形態では、センタボルト３０の下端近傍にバルブ２０を設けたが、センタボルト３０以外の棒状部材をカバー１５に設け、その棒状部材を用いてバルブ２０を設けてもよい。ただし、部品点数を減らし、簡単な構成にするためには、センタボルト３０の下端近傍にバルブ２０を設けることが望ましい。 Further, in the present embodiment, the valve 20 is provided near the lower end of the center bolt 30, but a rod-shaped member other than the center bolt 30 may be provided on the cover 15, and the valve 20 may be provided using the rod-shaped member. However, it is desirable to provide the valve 20 near the lower end of the center bolt 30 in order to reduce the number of parts and achieve a simple configuration.
　＜第２の実施の形態＞
　本発明の第１の実施の形態では、第１弁体２２を有するバルブ２０を用いたが、バルブの形態はこれに限られない。 <Second embodiment>
In the first embodiment of the present invention, the valve 20 having the first valve body 22 is used, but the form of the valve is not limited to this.
　本発明の第２の実施の形態は、空気を抜くための第２弁体をさらに有するバルブを用いる形態である。以下、第２の実施の形態にかかるサクションフィルタ２について説明する。なお、第１の実施の形態と同一の部分については、同一の符号を付し、説明を省略する。 ２ The second embodiment of the present invention uses a valve further having a second valve body for bleeding air. Hereinafter, the suction filter 2 according to the second embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
　図６は、サクションフィルタ２の概略を示す図であり、（Ａ）は平面図、（Ｂ）は側面視における断面図である。図６（Ａ）では、説明のため、カバー１５Ａの一部を切断している。サクションフィルタ２は、主として、ストレーナ部１０Ａと、バルブ２０Ａとを有する。 FIG. 6 is a view schematically showing the suction filter 2, in which (A) is a plan view and (B) is a cross-sectional view in a side view. In FIG. 6A, a part of the cover 15A is cut for explanation. The suction filter 2 mainly has a strainer section 10A and a valve 20A.
　ストレーナ部１０Ａは、主として、第１濾過部１１と、内筒１２と、下プレート１３と、シール部材１４と、カバー１５Ａと、第２濾過部１６と、を有する。カバー１５Ａは、略円板形状の板状部１５ｈと、板状部１５ｈに設けられた凸部１５ｉと、を有する。凸部１５ｉは、略円筒形状であり、板状部１５ｈから上向き（＋ｚ向き）、つまり第１濾過部１１と反対側に突出している。凸部１５ｉは内部が空洞（空間Ｓ３）であり、この空洞の壁面は内壁面１５ｋである。内壁面１５ｋは、板状部１５ｈの略中央に設けられた孔の壁面を兼用しており、空間Ｓ３はカバー１５Ａの下端面に開口している。 The strainer unit 10A mainly includes a first filtration unit 11, an inner cylinder 12, a lower plate 13, a seal member 14, a cover 15A, and a second filtration unit 16. The cover 15A has a substantially disk-shaped plate-like portion 15h and a protrusion 15i provided on the plate-like portion 15h. The convex portion 15i has a substantially cylindrical shape, and protrudes upward (+ z direction) from the plate-like portion 15h, that is, protrudes to the opposite side to the first filtering portion 11. The inside of the convex portion 15i is a cavity (space S3), and the wall surface of the cavity is an inner wall surface 15k. The inner wall surface 15k also serves as a wall surface of a hole provided substantially at the center of the plate-shaped portion 15h, and the space S3 is open at the lower end surface of the cover 15A.
　凸部１５ｉは上端面１５ｊを有し、上端面１５ｊには孔１５ａが設けられている。孔１５ａは、空間Ｓ３と、空間Ｓ２とを連通する。また、上端面１５ｊの略中央には孔（図示省略）が形成されており、この孔にはセンタボルト３０が挿入されている。センタボルト３０は、ナット３１により上端面１５ｊに固定されている。 The protrusion 15i has an upper end surface 15j, and a hole 15a is provided in the upper end surface 15j. The hole 15a communicates the space S3 with the space S2. A hole (not shown) is formed substantially at the center of the upper end surface 15j, and a center bolt 30 is inserted into this hole. The center bolt 30 is fixed to the upper end surface 15j by a nut 31.
　カバー１５Ａの下側（－ｚ側）かつ第１濾過部１１及び内筒１２の中空部には、孔１５ａを覆うようにバルブ２０Ａが設けられる。 バ ル ブ A valve 20A is provided below the cover 15A (−z side) and in a hollow portion of the first filtration unit 11 and the inner cylinder 12 so as to cover the hole 15a.
　図７、８、９は、サクションフィルタ２の概略を示す断面図であり、一部を拡大表示した図である。図７～９では、第１濾過部１１の図示を省略している。バルブ２０Ａは、主として、スリーブ２１と、第１弁体２２Ａと、弾性部材２３と、第２弁体２４と、を有する。 FIGS. 7, 8, and 9 are cross-sectional views schematically showing the suction filter 2, and are partially enlarged views. 7 to 9, illustration of the first filtration unit 11 is omitted. The valve 20A mainly includes a sleeve 21, a first valve body 22A, an elastic member 23, and a second valve body 24.
　第１弁体２２Ａは、スリーブ２１に設けられており、スリーブ２１に沿って移動可能である。作動油中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、第１弁体２２Ａが移動し、バルブ２０の開状態と閉状態とが切り替えられる。 １The first valve body 22A is provided on the sleeve 21 and is movable along the sleeve 21. When the air mixed in the hydraulic oil has a set pressure lower than the cavitation pressure at which bubbles are generated, the first valve body 22A moves, and the valve 20 is switched between the open state and the closed state.
　第１弁体２２Ａには、複数の空気孔２２ａが形成される。第１弁体２２Ａの上側には、第２弁体２４が設けられている。第２弁体２４は、略板状であり、作動油に沈む材料を用いて形成されている。第２弁体２４は、スリーブ２１に設けられており、スリーブ２１に沿って移動可能である。 複数 A plurality of air holes 22a are formed in the first valve body 22A. A second valve body 24 is provided above the first valve body 22A. The second valve body 24 is substantially plate-shaped, and is formed using a material that sinks in hydraulic oil. The second valve body 24 is provided on the sleeve 21 and is movable along the sleeve 21.
　図７は、バルブ２０Ａが閉じた状態（閉状態）を示す。バルブ２０Ａが閉状態のときには、第１弁体２２Ａは凸部１５ｉ内の空洞である空間Ｓ３を覆うようにカバー１５Ａの下端面に当接する。 FIG. 7 shows a state in which the valve 20A is closed (closed state). When the valve 20A is in the closed state, the first valve body 22A contacts the lower end surface of the cover 15A so as to cover the space S3 which is a cavity in the convex portion 15i.
　第２弁体２４は、第１弁体２２Ａとカバー１５Ａとの間に設けられており、バルブ２０Ａが閉状態にあるときは、第２弁体２４は凸部１５ｉ内、すなわち空間Ｓ３の内部に設けられる。 The second valve body 24 is provided between the first valve body 22A and the cover 15A. When the valve 20A is in the closed state, the second valve body 24 is in the convex portion 15i, that is, in the space S3. Is provided.
　サクションフィルタ２がタンク本体１０１の内部に設けられていない状態では、第２弁体２４は空気孔２２ａを覆う位置に位置する。そして、サクションフィルタ２に空気が入った状態で、サクションフィルタ２はタンク本体１０１の内部に装着される。サクションフィルタ２をタンク本体１０１の内部に貯留された作動油に沈めると、空気がカバー１５Ａの下側に溜まり、カバー１５Ａの下側に溜まった空気が空気孔２２ａを介して第２弁体２４を押し上げる。 で は When the suction filter 2 is not provided inside the tank main body 101, the second valve body 24 is located at a position covering the air hole 22a. Then, the suction filter 2 is mounted inside the tank main body 101 in a state where the air enters the suction filter 2. When the suction filter 2 is submerged in the hydraulic oil stored in the tank body 101, the air accumulates below the cover 15A, and the air accumulates below the cover 15A. Push up.
　図８は、第２弁体２４が上方向（＋ｚ方向）に移動したエア抜き状態を示す。このように、第２弁体２４が空気孔２２ａを覆わない位置まで押し上げられると、イニシャルエアが空気孔２２ａ及び孔１５ａを通ってサクションフィルタ２の外部へ排出される（図８二点鎖線矢印参照）。 FIG. 8 shows an air-bleeding state in which the second valve body 24 has moved upward (+ z direction). When the second valve element 24 is pushed up to a position not covering the air hole 22a, the initial air is discharged to the outside of the suction filter 2 through the air hole 22a and the hole 15a (see the two-dot chain line arrow in FIG. 8). reference).
　なお、空気孔２２ａの位置、大きさ、及び形状は図７、８等に示す形態に限られない。ただし、第２弁体２４を押し上げる空気圧を確保するためには、空気孔２２ａの直径は略５ｍｍ～略１０ｍｍ以上とすることが望ましい。 The position, size, and shape of the air holes 22a are not limited to those shown in FIGS. However, in order to secure an air pressure that pushes up the second valve body 24, it is desirable that the diameter of the air hole 22a be approximately 5 mm to approximately 10 mm or more.
　図９は、バルブ２０Ａが開いた状態（開状態）を示す。空間Ｓ１の内部の負圧が大きくなり、作動油中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、弾性部材２３の付勢力に抗して第１弁体２２Ａがスリーブ２１に沿って下方向に移動する。なお、第２弁体２４は作動油に沈むため、第１弁体２２Ａと共に第２弁体２４が下方向に移動する。 FIG. 9 shows a state in which the valve 20A is open (open state). When the negative pressure inside the space S1 increases and the set pressure is lower than the cavitation pressure at which the air mixed in the hydraulic oil becomes bubbles, the first valve body 22A is turned into a sleeve against the urging force of the elastic member 23. It moves downward along 21. Since the second valve body 24 sinks in the hydraulic oil, the second valve body 24 moves downward together with the first valve body 22A.
　この結果、第１弁体２２Ａがカバー１５Ａの下端面から離れ、空間Ｓ１と空間Ｓ３とが連通され、バルブ２０Ａが開状態になる。開状態では、孔１５ａを介して作動油が空間Ｓ２から空間Ｓ１、Ｓ３へと流入する（図９白抜き矢印参照）。 As a result, the first valve body 22A is separated from the lower end surface of the cover 15A, the space S1 and the space S3 are communicated, and the valve 20A is opened. In the open state, the hydraulic oil flows from the space S2 into the spaces S1 and S3 via the hole 15a (see the white arrows in FIG. 9).
　本実施の形態によれば、サクションフィルタ２でのキャビテーションの発生を防止することができる。また、第２弁体２４を有するバルブ２０Ａを用いることで、サクションフィルタ２（空間Ｓ１）内の空気を空間Ｓ２へ排出することができる。そのため、作動油の流れに乗って空間Ｓ２内の空気がポンプへ流出しないようにすることができる。 According to the present embodiment, the occurrence of cavitation in the suction filter 2 can be prevented. Further, by using the valve 20A having the second valve body 24, the air in the suction filter 2 (the space S1) can be discharged to the space S2. Therefore, it is possible to prevent the air in the space S2 from flowing out to the pump by riding the flow of the hydraulic oil.
　本実施の形態によれば、第１弁体２２Ａが略板状であるため、第１弁体２２Ａと内筒１２との間に空気が溜まりにくい。そのため、サクションフィルタ２の稼働時間が長くなり、空間Ｓ１内に空気が溜まったとしても、その空気は第１弁体２２Ａの下側に溜まり、第２弁体２４を押し上げることで、空気を空間Ｓ２へ排出することができる。 According to the present embodiment, since the first valve body 22A has a substantially plate shape, air does not easily accumulate between the first valve body 22A and the inner cylinder 12. Therefore, the operation time of the suction filter 2 is prolonged, and even if air accumulates in the space S1, the air accumulates below the first valve body 22A and pushes up the second valve body 24 to remove air. It can be discharged to S2.
　なお、本実施の形態では、板状部１５ｈと凸部１５ｉとが一部品となったカバー１５Ａを用いたが、板状部１５ｈと凸部１５ｉとを別部品とし、これらを組み立てることでカバーとしてもよい。 In this embodiment, the cover 15A in which the plate-shaped portion 15h and the projection 15i are formed as one component is used. However, the plate-shaped portion 15h and the projection 15i are formed as separate components, and the cover 15A is assembled by assembling these components. It may be.
　また、本実施の形態では、凸部１５ｉを有するカバー１５Ａを用い、略板状の第１弁体２２Ａを有するバルブ２０Ａを用いたが、空気を抜きつつキャビテーションを防止するバルブの形態はこれに限られない。図１０は、変形例にかかるサクションフィルタ２Ａの概略を示す断面図であり、一部を拡大表示した図である。サクションフィルタ２Ａは、略板状のカバー１５と、バルブ２０Ｂと、を用いる。 Further, in the present embodiment, the cover 15A having the convex portion 15i is used, and the valve 20A having the substantially plate-shaped first valve body 22A is used. Not limited. FIG. 10 is a cross-sectional view schematically showing a suction filter 2A according to a modified example, and is a partially enlarged view. The suction filter 2A uses a substantially plate-shaped cover 15 and a valve 20B.
　バルブ２０Ｂは、主として、スリーブ２１と、第１弁体２２Ｂと、弾性部材２３と、第２弁体２４と、を有する。第１弁体２２Ｂは、スリーブ２１に設けられており、スリーブ２１に沿って移動可能である。 The valve 20B mainly includes a sleeve 21, a first valve body 22B, an elastic member 23, and a second valve body 24. The first valve body 22B is provided on the sleeve 21 and is movable along the sleeve 21.
　第１弁体２２Ｂは有底略円筒形状であり、底面には複数の空気孔２２ａが形成される。第２弁体２４は、第１弁体２２Ｂの上側に設けられており、スリーブ２１に沿って移動可能である。 The first valve body 22B has a substantially cylindrical shape with a bottom, and has a plurality of air holes 22a formed in the bottom surface. The second valve body 24 is provided above the first valve body 22B, and is movable along the sleeve 21.
　空間Ｓ１の内部の負圧がセット圧になると、弾性部材２３の付勢力に抗して第１弁体２２Ｂがスリーブ２１に沿って下方向に移動する。この結果、第１弁体２２Ｂがカバー１５Ａの下端面から離れ、空間Ｓ１と空間Ｓ３とが連通され、バルブ２０Ｂが開状態になる。また、空気が空気孔２２ａを介して第２弁体２４を押し上げると、空間Ｓ１内の空気が空間Ｓ３を通って空間Ｓ２へ排出される。 When the negative pressure inside the space S1 becomes the set pressure, the first valve body 22B moves downward along the sleeve 21 against the urging force of the elastic member 23. As a result, the first valve body 22B separates from the lower end surface of the cover 15A, the space S1 and the space S3 communicate with each other, and the valve 20B is opened. When the air pushes up the second valve body 24 via the air hole 22a, the air in the space S1 is discharged to the space S2 through the space S3.
　ただし、サクションフィルタ２Ａでは、空間Ｓ１の内部、特に第１弁体２２Ｂと内筒１２との間（図１０の二点鎖線で囲まれた領域）に空気が溜まりやすいため、サクションフィルタ２のように、凸部１５ｉを有するカバー１５Ａを用い、略板状の第１弁体２２Ａを有するバルブ２０Ａを用いることが望ましい。 However, in the suction filter 2A, since air tends to accumulate inside the space S1, particularly between the first valve body 22B and the inner cylinder 12 (the area surrounded by the two-dot chain line in FIG. 10), the suction filter 2A It is preferable to use a cover 15A having a convex portion 15i and a valve 20A having a substantially plate-shaped first valve body 22A.
　以上、この発明の実施形態を、図面を参照して詳述してきたが、具体的な構成はこの実施形態に限られるものではなく、この発明の要旨を逸脱しない範囲の設計変更等も含まれる。例えば、上記の実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、実施形態の構成に他の構成の追加、削除、置換等をすることが可能である。 The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and may include design changes and the like without departing from the gist of the present invention. . For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of the embodiment can be replaced with the configuration of another embodiment, and another configuration can be added, deleted, or replaced with the configuration of the embodiment.
　また、本発明において、「略」とは、厳密に同一である場合のみでなく、同一性を失わない程度の誤差や変形を含む概念である。例えば、「略直交」とは、厳密に直交の場合には限られず、例えば数度程度の誤差を含む概念である。また、例えば、単に直交、平行、一致等と表現する場合において、厳密に直交、平行、一致等の場合のみでなく、略平行、略直交、略一致等の場合を含むものとする。 Also, in the present invention, “substantially” is a concept that includes not only the case of exactly the same but also an error or a deformation that does not lose the identity. For example, “substantially orthogonal” is not limited to a strictly orthogonal case, and is a concept that includes, for example, an error of about several degrees. In addition, for example, the expression “perpendicular, parallel, coincidence, etc.” includes not only the case of strictly orthogonal, parallel, coincidence, etc., but also the case of approximately parallel, approximately orthogonal, approximately coincidence, etc.
　また、本発明において「近傍」とは、基準となる位置の近くのある範囲（任意に定めることができる）の領域を含むことを意味する。例えば、端近傍という場合に、端の近くのある範囲の領域であって、端を含んでもいても含んでいなくてもよいことを示す概念である。 に お い て In the present invention, “near” means that a region within a certain range (can be arbitrarily determined) near a reference position is included. For example, the term “near the end” is a concept indicating that it is a region in a certain range near the end, and may or may not include the end.
１、２、２Ａ：サクションフィルタ
１０、１０Ａ：ストレーナ部
１１　　　：第１濾過部
１２　　　：内筒
１３　　　：下プレート
１３ａ　　：流出口
１４　　　：シール部材
１５、１５Ａ：カバー
１５ａ　　：孔
１５ｈ　　：板状部
１５ｉ　　：凸部
１５ｊ　　：上端面
１５ｋ　　：内壁面
１６　　　：第２濾過部
１６ａ　　：下端面
２０、２０Ａ、２０Ｂ：バルブ
２１　　　：スリーブ
２１ａ　　：フランジ
２２、２２Ａ、２２Ｂ：第１弁体
２２ａ　　：空気孔
２３　　　：弾性部材
２４　　　：第２弁体
３０　　　：センタボルト
３０ａ　　：雄ネジ部
３１、３２、３３：ナット
１００　　：作動油タンク
１０１　　：タンク本体
１０１ａ　：流入口
１０１ｂ　：開口部
１０１ｃ　：開口部
１０１ｄ　：流出部
１０１ｅ　：筒状部
１０１ｆ　：仕切板
１０２、１０３：蓋体
１０４　　：サクションパイプ
１０５　　：ボルト
１１０　　：リターンフィルタ
１１１　　：ポンプ 1, 2, 2A: Suction filter 10, 10A: Strainer section 11: First filtration section 12: Inner cylinder 13: Lower plate 13a: Outlet port 14: Seal member 15, 15A: Cover 15a: Hole 15h: Plate section 15i : Convex part 15j: upper end face 15k: inner wall face 16: second filtration part 16a: lower end face 20, 20A, 20B: valve 21: sleeve 21a: flange 22, 22A, 22B: first valve body 22a: air hole 23: Elastic member 24: second valve body 30: center bolt 30a: male screw portions 31, 32, 33: nut 100: hydraulic oil tank 101: tank body 101a: inlet 101b: opening 101c: opening 101d: outlet 101e : Cylindrical portion 101f: partition plates 102 and 103: lid 104: suction pipe 105: bolt 1 10: Return filter 111: Pump

Claims (6)

  1. 　油が貯留されるタンク内に設けられ、前記タンク内からポンプに吸入される液体を濾過するサクションフィルタであって、
    　縦糸と横糸とを交差させた網目状の薄板をプリーツ状に折り曲げて形成した略筒状の第１濾過部と、
    　前記第１濾過部の上端面に設けられ、前記第１濾過部の上側全体を覆うカバーと、
    　前記第１濾過部の下端面に設けられ、前記第１濾過部の下側全体を覆う下プレートであって、前記液体を前記ポンプへ流出させる流出口を有する下プレートと、
    　前記カバーの下側かつ前記第１濾過部の中空部に設けられたバルブと、
    　を備え、
    　前記カバーは、孔を有し、
    　前記バルブは、前記カバーに立設された棒状部材と、前記棒状部材に設けられ、前記棒状部材に沿って移動可能な第１弁体と、両端が前記第１弁体及び前記棒状部材に設けられ、前記第１弁体を前記カバーに向けて押し上げる弾性部材と、を有し、
    　前記バルブは、前記第１濾過部、前記カバー及び前記下プレートにより形成された空間の内部の圧力が前記液体中に混入している空気が気泡となるキャビテーション圧より小さいセット圧になると、前記第１弁体が前記孔を塞ぐ閉状態と前記第１弁体が前記孔を塞がない開状態とを切り替えるように構成されている
    　ことを特徴とするサクションフィルタ。     A suction filter is provided in a tank in which oil is stored, and filters a liquid sucked into the pump from the tank,
    A substantially cylindrical first filtration unit formed by bending a mesh-like thin plate in which warp and weft cross each other into a pleated shape;
    A cover provided on an upper end surface of the first filtration unit and covering an entire upper side of the first filtration unit;
    A lower plate provided on a lower end surface of the first filtration unit and covering an entire lower side of the first filtration unit, the lower plate having an outlet through which the liquid flows out to the pump;
    A valve provided below the cover and in a hollow portion of the first filtration unit;
    With
    The cover has a hole,
    The valve includes a bar-shaped member erected on the cover, a first valve body provided on the bar-shaped member and movable along the bar-shaped member, and both ends provided on the first valve body and the bar-shaped member. An elastic member that pushes up the first valve body toward the cover,
    When the pressure inside the space formed by the first filtration unit, the cover, and the lower plate becomes a set pressure smaller than the cavitation pressure at which air mixed in the liquid becomes bubbles, A suction filter characterized in that it is configured to switch between a closed state in which one valve element closes the hole and an open state in which the first valve element does not close the hole.
  2. 　請求項１に記載のサクションフィルタであって、
    　前記第１弁体には空気孔が形成され、
    　前記バルブは、前記棒状部材に設けられ、前記棒状部材に沿って移動可能な第２弁体を有し、
    　前記第２弁体は、前記第１弁体と前記カバーとの間に設けられ、前記空気孔を覆う位置と前記空気孔を覆わない位置との間で移動可能である
    　ことを特徴とするサクションフィルタ。     The suction filter according to claim 1, wherein
    An air hole is formed in the first valve body,
    The valve has a second valve body provided on the rod-shaped member and movable along the rod-shaped member,
    The second valve body is provided between the first valve body and the cover, and is movable between a position covering the air hole and a position not covering the air hole. filter.
  3. 　請求項２に記載のサクションフィルタであって、
    　前記カバーは、板状部と、前記板状部に設けられ、前記第１濾過部と反対側に突出する凸部を有し、
    　前記凸部は、内部が空洞であり、前記空洞は前記カバーの下端面に開口しており、
    　前記バルブが前記閉状態のときに、前記第１弁体は前記空洞を覆うように前記カバーの下端面に当接し、前記第２弁体は前記空洞の内部に設けられる
    　ことを特徴とするサクションフィルタ。     The suction filter according to claim 2, wherein
    The cover has a plate-shaped portion and a projection provided on the plate-shaped portion and protruding on a side opposite to the first filtering portion,
    The convex portion has a hollow inside, and the hollow is open at a lower end surface of the cover,
    When the valve is in the closed state, the first valve body contacts the lower end surface of the cover so as to cover the cavity, and the second valve body is provided inside the cavity. filter.
  4. 　請求項１から３のいずれか一項に記載のサクションフィルタであって、
    　前記カバーの上側に、前記孔を覆うように設けられた第２濾過部を備え、
    　前記第２濾過部の網目の大きさは、前記第１濾過部の網目の大きさより大きい
    　ことを特徴とするサクションフィルタ。     The suction filter according to any one of claims 1 to 3, wherein
    A second filtering unit provided on the upper side of the cover so as to cover the hole,
    The size of the mesh of the second filtration unit is larger than the size of the mesh of the first filtration unit.
  5. 　請求項４に記載のサクションフィルタであって、
    　前記第２濾過部は傘状であり、前記第２濾過部の略円環形状の下端面が前記カバーと当接する
    　ことを特徴とするサクションフィルタ。     The suction filter according to claim 4, wherein
    A suction filter, wherein the second filtration unit has an umbrella shape, and a substantially annular lower end surface of the second filtration unit is in contact with the cover.
  6. 　請求項１から５のいずれか一項に記載のサクションフィルタであって、
    　鉛直方向に延在し、下端近傍が前記カバーに設けられたロッド部を備え、
    　前記棒状部材は、前記ロッド部の前記カバーの下側に存在する部分を含む
    　ことを特徴とするサクションフィルタ。     The suction filter according to any one of claims 1 to 5, wherein
    A rod extending in the vertical direction and having a lower end near the cover is provided on the cover,
    The suction filter according to claim 1, wherein the rod-shaped member includes a portion of the rod portion below the cover.
PCT/JP2019/029668 2018-08-06 2019-07-29 Suction filter WO2020031775A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111804059A (en) * 2020-07-23 2020-10-23 朱琳 Lees solid-liquid separation equipment is used in white spirit processing
CN112156533A (en) * 2020-12-01 2021-01-01 潍坊维润金属科技有限公司 Industrial sewage purification equipment

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JP6830987B2 (en) * 2019-08-01 2021-02-17 ヤマシンフィルタ株式会社 Suction strainer
WO2023140296A1 (en) * 2022-01-20 2023-07-27 ヤマシンフィルタ株式会社 Suction strainer

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JPS60121370A (en) * 1983-11-30 1985-06-28 Hitachi Constr Mach Co Ltd Pressure control valve
JPH0622577U (en) * 1991-11-12 1994-03-25 東芝機械株式会社 Suction filter
JP2008290004A (en) * 2007-05-24 2008-12-04 Yamashin-Filter Corp Filtration apparatus, and tank device
WO2016204117A1 (en) * 2015-06-18 2016-12-22 ヤマシンフィルタ株式会社 Suction strainer
WO2018199102A1 (en) * 2017-04-27 2018-11-01 ヤマシンフィルタ株式会社 Strainer

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Publication number Priority date Publication date Assignee Title
JPS60121370A (en) * 1983-11-30 1985-06-28 Hitachi Constr Mach Co Ltd Pressure control valve
JPH0622577U (en) * 1991-11-12 1994-03-25 東芝機械株式会社 Suction filter
JP2008290004A (en) * 2007-05-24 2008-12-04 Yamashin-Filter Corp Filtration apparatus, and tank device
WO2016204117A1 (en) * 2015-06-18 2016-12-22 ヤマシンフィルタ株式会社 Suction strainer
WO2018199102A1 (en) * 2017-04-27 2018-11-01 ヤマシンフィルタ株式会社 Strainer

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111804059A (en) * 2020-07-23 2020-10-23 朱琳 Lees solid-liquid separation equipment is used in white spirit processing
CN112156533A (en) * 2020-12-01 2021-01-01 潍坊维润金属科技有限公司 Industrial sewage purification equipment
CN112156533B (en) * 2020-12-01 2021-04-23 潍坊维润金属科技有限公司 Industrial sewage purification equipment

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