JP2018130650A - Filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a swirl flow at the time of liquid inflow and prevent the swirl flow from generated in the vicinity of a filter element.SOLUTION: An inflow pipe which inflows a liquid into a filter case from a tangential direction at an arbitrary point of a side face of the filter case is provided on the side face of the filter case. A plurality of ribs are provided approximately along a central axis of the filter case and the filter element, a position of the rib in plan view is between the filter element and the filter case, and a position in a height direction of the ribs is a position that is on a lower side of the inflow pipe and overlaps a first plate-like member covering the upper end of a filter material having an approximately cylindrical shape.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a filter device.

  In Patent Document 1, a cylindrical main body container having a central axis set vertically, a cylindrical filtration element that is provided coaxially with the main body container in the main body container and removes foreign matters contained in the liquid, and a main body There is disclosed a filter including an inflow pipe that is provided in a tangential direction with respect to a circumferential wall surface of a container and that introduces a liquid containing a separation object. In Patent Document 1, a swirling flow is generated, and air or other gas contained in a liquid is raised above the main body container.

JP 2007-296492 A

  However, in the invention described in Patent Document 1, since a swirling flow is generated along the outer peripheral surface of the filtration element, the filtration element may be rotated by the flow of the liquid.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a filter device capable of generating a swirling flow when liquid flows in and not generating a swirling flow in the vicinity of the filter element. To do.

  In order to solve the above problems, a filter device according to the present invention is provided, for example, in a substantially cylindrical bottomed filter case, a lid member that covers an open end of the upper part of the filter case, and the inside of the filter case. A filter element comprising a substantially cylindrical filter medium, a first plate member covering an upper end of the filter medium, and a second plate member covering a lower end of the filter medium, and a side surface of the filter case An inflow pipe that causes a liquid to flow into the filter case from a tangential direction at an arbitrary point on the side surface of the filter case and generates a swirling flow in the inflowed liquid, the lid in the height direction An inflow pipe provided between a member and the filter element, and a rib provided so as to substantially follow a central axis of the filter case and the filter element A rib in which the position in plan view is between the filter element and the filter case, and the position in the height direction is a position below the inflow pipe and a position overlapping the first plate member. A plurality of rectifying sections and a substantially cylindrical outflow section penetrating the bottom surface of the second plate-shaped member, one end being provided in the hollow portion of the filter medium and the other end being provided outside the filter case And an outflow portion.

  According to the filter device of the present invention, the side surface of the filter case is provided with an inflow pipe through which liquid flows into the filter case from a tangential direction at an arbitrary point on the side surface of the filter case. As a result, a swirl flow can be generated in the hydraulic oil when the liquid flows in. In addition, a plurality of ribs are provided so as to be substantially along the center axis of the filter case and the filter element, the position of the rib in plan view is between the filter element and the filter case, and the position of the rib in the height direction is the inflow pipe. It is a position which overlaps with the 1st plate-shaped member which covers a lower position and the upper end of a substantially cylindrical filter medium. In the process in which the hydraulic oil flows between the filter element and the case body through the gaps between the ribs, the direction of the hydraulic oil flow changes from the swirl flow to the downward flow. Thereby, it is possible to prevent the swirling flow from being generated in the hydraulic oil in the vicinity of the filter element.

  Here, the rectifying unit has a substantially disc-shaped plate-like part having the rib formed on the periphery thereof, and a convex part protruding upward from the plate-like part, and the position of the convex part in the height direction And the position of the inflow pipe in the height direction may overlap. Thereby, the flow path of hydraulic fluid can be narrowed and hydraulic fluid can be turned more reliably.

  Here, a substantially cylindrical concave portion is formed on the lower surface of the lid member, and an air rectifying member is provided inside the concave portion, and the air rectifying member has a wide surface substantially the same as the central axis. There are a plurality of parallel first fins, and the plurality of first fins are provided so as to protrude in the radial direction. Inside the lid member, a valve and an air vent hole are provided above the air rectifying member. May be. Thereby, air flows from bottom to top along the first fin. Therefore, air is easily discharged out of the return filter.

  Here, the air rectifying member is provided with a second fin having a wide surface substantially orthogonal to the central axis between the adjacent first fins, and the outer periphery of the second fin in a plan view is It may be smaller than the outer periphery of the first fin. Thereby, the flow path of air becomes narrow and the flow of air becomes quick. Therefore, air is more easily discharged out of the return filter.

  Here, on the lower surface of the lid member, a substantially cylindrical tubular portion having a substantially truncated cone side surface is arranged such that the upper surface with a small area is positioned on the upper side and the bottom surface with a large area is positioned on the lower side. The recessed portion may be provided in a region surrounded by the tubular portion. Thereby, air flows upward along the cylindrical part. Therefore, air is easily discharged out of the return filter.

  According to the present invention, it is possible to generate a swirling flow when the liquid flows in and not to generate a swirling flow in the vicinity of the filter element.

It is a figure which shows the outline of the hydraulic oil tank 100 in which the return filter 1 which is one Embodiment of this invention was provided inside. 2 is a cross-sectional view showing an outline of a return filter 1. FIG. It is a perspective view which shows the outline of the return filter 1 when cut | disconnecting along a centerline. It is AA sectional drawing of FIG. 3 is a perspective view showing an outline of a rectifying member 32. FIG. It is the figure which expanded and displayed the principal part of the cover body. FIG. 6 is a perspective view showing an outline of an air rectifying member 47. It is BB sectional drawing of FIG. It is sectional drawing which shows the outline of the return filter 2 which is one Embodiment of this invention. It is CC sectional drawing of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, although hydraulic oil is demonstrated to an example as a fluid, this invention is applicable to various fluids other than hydraulic oil. Moreover, although this invention demonstrates as an example the return filter provided in a tank as an example of a filter apparatus, the filter apparatus of this invention is not limited to a return filter.

<First Embodiment>
FIG. 1 is a cross-sectional view schematically illustrating a hydraulic oil tank 100 in which a return filter 1 according to an embodiment of the present invention is provided (however, hatching indicating the cross section is omitted).

  The hydraulic oil tank 100 is installed in a working machine (not shown) (for example, a hydraulic device), and is a tank for storing hydraulic oil provided in a hydraulic circuit for hydraulic oil supplied to the hydraulic device. is there. In the hydraulic circuit, the hydraulic oil is introduced into the hydraulic oil tank 100 through the hydraulic device.

  The hydraulic oil tank 100 includes, for example, a box-shaped tank body 101, and the inside of the tank body 101 is hollow. Inside the tank main body 101, a return filter 1 is mainly provided.

  A hole 101b into which the return filter 1 is inserted is formed in the upper surface 101a of the tank body 101. The return filter 1 is fixed to the upper surface 101a.

  Next, the return filter 1 will be described. The return filter 1 mainly includes a filter case 10, a filter element 20, a rectifying unit 30, a lid member 40, and an outflow unit 50.

  FIG. 2 is a cross-sectional view schematically showing the return filter 1. FIG. 3 is a perspective view showing an outline of the return filter 1, and shows a state where the return filter 1 is cut along the center line. 2 and 3, hatching indicating a cross section is omitted.

  The filter case 10 is a bottomed substantially cylindrical member and is made of metal. The filter case 10 mainly includes a case main body 11 and attachment members 12 and 13.

  The case main body 11 is a bottomed substantially cylindrical member, and an inflow pipe 14 is provided on the side surface 11a. The inflow pipe 14 and the inside of the case body 11 are communicated with each other through the opening 11b.

  The inflow pipe 14 causes the working oil to flow into the filter case 10 from a tangential direction at an arbitrary point on the side surface 11a, and causes the working oil that has flowed into the filter case 10 to generate a swirling flow. The inflow pipe 14 is provided between the lid member 40 and the filter element 20 in the height direction.

  An attachment member 12 is provided near the upper end of the case body 11. The attachment member 12 is attached to the upper surface 101a. A lid member 40 is provided on the upper side (+ z side) of the attachment member 12. An attachment member 13 is provided on the lower side (−z side) of the attachment member 12. The attachment members 12 and 13 are not essential.

  The bottom surface 11 c of the case body 11 is provided with a substantially cylindrical outflow portion 50 that penetrates the bottom surface 11 c. The outflow part 50 is a substantially cylindrical member formed of metal. The outflow part 50 is formed with a plurality of holes 50a through which hydraulic oil passes.

  The filter element 20 is a substantially cylindrical member as a whole, and is provided inside the filter case 10. The filter element 20 mainly includes an inner cylinder 21, a filter medium 22, plates 23 and 24, and valves 25 and 26.

  The filter medium 22 is for filtering the hydraulic oil and has a substantially cylindrical shape having a thickness in the radial direction. The filter medium 22 is formed by folding a filter paper made of synthetic resin, paper, or the like, and connecting both ends of the filter paper that has been folded and rounding it into a cylindrical shape.

  The inner cylinder 21 is a substantially cylindrical member made of metal and is provided inside the filter medium 22. The height of the inner cylinder 21 and the height of the filter medium 22 are substantially the same. The inner cylinder 21 is formed with a hole 21a through which hydraulic oil passes substantially over the entire surface.

  A plate 23 is provided at the lower ends of the inner cylinder 21 and the filter medium 22. The plate 23 is a substantially disc-shaped or bottomed substantially cylindrical member formed of resin or metal. An opening 23 a is formed in the approximate center of the plate 23.

  The outflow part 50 is inserted in the opening part 23a. One end of the outflow portion 50 is provided in the hollow portion of the filter element 20 (inner cylinder 21), and the other end is provided outside the filter case 10.

  A plate 24 that is a substantially plate-like member is provided on the upper ends of the inner cylinder 21 and the filter medium 22. The plate 24 is provided with a valve 25. The valve 25 opens and closes according to the difference between the pressure inside the case body 11 (space S1) and the pressure inside the filter element 20 (space S2).

  The plate 24 is provided with a valve 26. The valve 26 releases air (initial air) that filled the space S2 before the hydraulic oil flows into the space S2 from the space S2 to the space S1.

  The rectifying unit 30 is a member that adjusts the flow of hydraulic oil that flows inside the case body 11. The rectifying unit 30 mainly includes a plate-like member 31 and a rectifying member 32. Hereinafter, the rectifying unit 30 will be described with reference to FIGS.

  4 is a cross-sectional view taken along the line AA of FIG. 2 (however, hatching indicating the cross section is omitted). The plate-like member 31 is a substantially disk-shaped member, and is formed with a hole 31a into which a convex portion 32a (described in detail later) is inserted and a hole 31b through which hydraulic oil passes. The holes 31b are long holes along the outer peripheral surface of the plate-like member 31, and a plurality of holes 31b are formed at different positions in the circumferential direction. The hole 31b is formed so as to overlap with the bases of the ribs 32c and 32d (detailed later) in plan view. However, the position of the hole 31b is not limited to this.

  FIG. 5 is a perspective view showing an outline of the rectifying member 32. The rectifying member 32 includes a substantially semispherical convex portion 32a protruding upward and a plate-like portion 32b.

  The convex portion 32 a is formed at the approximate center of the rectifying member 32. The convex portion 32a is hollow, and a hole 32g for allowing air to escape upward is formed at the top of the convex portion 32a.

  A plurality of ribs 32c and 32d are formed on the outer periphery of the plate-like portion 32b. The ribs 32c and 32d are formed so as to be substantially along the z direction (the axis A of the filter case 10 and the filter element 20). The height of the rib 32d is higher than the height of the rib 32c, and the position of the upper surface 32e of the rib 32d is higher than the position of the upper surface 32f of the rib 32c. A plate-like member 31 is placed on the upper surface 32e and fixed with screws or the like. Therefore, a gap through which hydraulic oil flows is formed between the lower surface 31c (see FIG. 2) of the plate-like member 31 and the upper surface 32f.

  Returning to the description of FIG. The outer peripheral surfaces of the ribs 32 c and 32 d are substantially in contact with the inner peripheral surface of the case body 11. Accordingly, the hydraulic oil that has passed through the hole 31b flows downward (−z direction) through the gap between the ribs 32c and 32d (see the hatched portion in FIG. 4), and between the filter case 10 and the filter element 20. Flow into.

  Returning to the description of FIGS. The diameter of the convex portion 32 a is smaller than the diameter of the filter element 20. Further, the position in the height direction of the convex portion 32a and the position in the height direction of the inflow pipe 14 overlap. Therefore, the flow path of the hydraulic oil is narrowed, and the turning of the hydraulic oil flowing into the space S1 is promoted. However, the shape and size of the convex portion 32a are not limited to this.

  The ribs 32c and 32d are provided between the filter case 10 (case body 11) and the filter element 20 in plan view (viewed from the z direction). The ribs 32 c and 32 d are positions where the height direction is below the inflow pipe 14 and overlaps the plate 24. Accordingly, when the hydraulic oil flows between the filter case 10 and the filter element 20, the hydraulic oil flows downward.

  The lid member 40 is a substantially plate-like member that covers the upper open end of the filter case 10. The lid member 40 is detachably attached to the filter case 10.

  The lid member 40 is made of metal and mainly includes a lid body 41 and a cylindrical member 42. The cylindrical member 42 is a substantially cylindrical member, and is attached to the lower side of the lid body 41 with a screw or the like. The rectifying unit 30 is fixed to the lower side of the cylindrical member 42 with screws or the like. Thereby, the rectification | straightening part 30 and the cover member 40 are assembled as one component.

  When the rectifying unit 30 and the lid member 40 are removed from the filter case 10, the filter element 20 can be extracted from the opening end of the upper part of the filter case 10. After the used filter element 20 is extracted, the replaced filter element 20 is inserted from the upper opening end of the filter case 10, and the rectifying unit 30 and the lid member 40 are attached to the filter case 10. The downward force is urged by the elastic member 51, whereby the filter element 20 is fixed inside the case body 11.

  FIG. 6 is an enlarged view of the main part of the lid 41. The lid body 41 mainly includes a substantially disc-shaped plate-like portion 41a and a substantially cylindrical-shaped tubular portion 41b. The cylindrical portion 41b has a substantially truncated cone shape on the side surface. The cylindrical portion 41b is provided on the lower side of the plate-like portion 41a so that the upper surface with a small area is positioned on the upper side and the bottom surface with a large area is positioned on the lower side.

  A substantially cylindrical recess 41c is formed in the lower surface of the lid 41 and in an area surrounded by the cylindrical portion 41b. A substantially cylindrical mounting member 46 is inserted into the recess 41c. A recess 46 a is formed on the upper side of the attachment member 46. Further, the lid 41 is formed with a recess 41d and an air vent hole 41e communicating with the recess 41d. A float 48 formed so as to float on hydraulic fluid is inserted into the space formed by the recess 41d and the recess 46a. The recess 46 a, the recess 41 d and the float 48 constitute a valve 49. In addition, the shape of the recessed part 46a and the recessed part 41d is not restricted to this. For example, a step may be formed on the side surface of the recess 46a or the recess 41d.

  A substantially cylindrical recess 46b communicating with the recess 46a is formed below the attachment member 46. The recess 46 b corresponds to a recess formed on the lower side of the lid member 40. The air rectifying member 47 is inserted into the recess 46b. A plate-like member 45 is provided below the recess 46 b, and a hole 45 a is formed in the approximate center of the plate-like member 45. A valve 49 and an air vent hole 41 e are provided above the recess 46 b (air rectifying member 47) and inside the lid body 41.

  The cylindrical portion 41b, the plate-like member 45, the mounting member 46, the air rectifying member 47, the valve 49, and the air vent hole 41e constitute an air vent portion. Hereinafter, the air vent will be described in detail.

  FIG. 7 is a perspective view showing an outline of the air rectifying member 47. The air rectifying member 47 includes substantially plate-like fins 47a and 47b. The fin 47a is provided so that a wide surface is substantially parallel to the z direction (axis A) and protrudes in the circumferential direction. The wide surface of the fin 47b is substantially orthogonal to the z direction (axis A), and is provided between the adjacent fins 47a and 47a. The fin 47b is provided in the approximate center of the fin 47a in the height direction. In the present embodiment, the eight fins 47a and the seven fins 47b are provided. However, the number of the fins 47a and 47b may be plural, and the number of the fins 47a and 47b is not limited thereto. However, the position, size, and shape of the fins 47b are not limited to this. Further, the fin 47b is not essential.

  8 is a cross-sectional view taken along line BB in FIG. A convex portion 47c protruding outward is formed on a part of the fin 47a. The air rectifying member 47 is provided inside the concave portion 46b by inserting the convex portion 47c into the concave portion 46c formed on the inner peripheral surface of the concave portion 46b. The outer peripheral surface of the fin 47a contacts the inner peripheral surface of the recess 46b, but the outer peripheral surface of the fin 47b does not contact the inner peripheral surface of the recess 46b. Therefore, the space between the fin 47a and the fin 47a, and the space between the outer peripheral surface of the fin 47b and the inner peripheral surface of the recess 46b serves as a passage for air.

  Next, the function of the return filter 1 configured as described above will be described with reference to FIGS. 2 and 6, the solid line arrows indicate the flow of hydraulic oil, and the two-dot chain line arrows indicate the flow of air.

  First, the flow of hydraulic oil will be described with reference to FIG. During the operation of the hydraulic device, hydraulic oil flows in the hydraulic circuit. As shown in FIG. 2, the hydraulic oil flows into the space S1 through the inflow pipe 14 and the opening 11b. Since the hydraulic oil flows into the space S1 from the tangential direction at an arbitrary point on the side surface 11a, the hydraulic oil turns between the convex portion 32a and the case body 11.

  The hydraulic oil flows downward while turning. The hydraulic oil that has passed through the hole 31b (see FIGS. 3 and 4) passes through the gap between the lower surface 31c and the upper surface 32f, and then passes through the gap between the ribs 32c and 32d (see the shaded portion in FIG. 4). And the case main body 11. In this process, since the flow direction of the hydraulic oil is changed from the swirl flow to the downward flow, the hydraulic oil does not swirl along the outer peripheral surface of the filter element 20 (or the swirl flow becomes weak). Therefore, the filter element 20 does not rotate due to the flow of hydraulic oil.

  The hydraulic oil that flows between the filter element 20 and the case body 11 passes through the filter medium 22 and flows into the inner cylinder 21 (space S2). The filtered hydraulic oil is discharged from the return filter 1 through the outflow portion 50 from the hollow portion of the inner cylinder 21. As a result, the hydraulic oil is filtered by the return filter 1 and stored in the hydraulic oil tank 100.

  The hydraulic oil stored in the hydraulic oil tank 100 flows out of the hydraulic oil tank 100 through a strainer (not shown) or the like. As a result, the filtered hydraulic oil is supplied to the hydraulic device again.

  Since the hydraulic oil flowing into the space S1 is swirling, air contained in the liquid gathers, becomes large bubbles, is removed from the hydraulic oil, and rises above the case body 11. Here, the flow of air will be described with reference to FIG.

  Since the cylindrical part 41b is provided on the lower side of the lid body 41, the air flows upward along the cylindrical part 41b. Thereafter, the air flows into the recess 46b through the hole 45a.

  The air that has flowed into the recess 46b flows upward between the air rectifying member 47 and the recess 46b. In particular, by flowing air along the fins 47a, the air flow is surely upward. Moreover, the flow of air becomes quick because a flow path becomes narrow with the fin 47b. In this way, the air easily flows from the space S <b> 1 toward the valve 49 by passing through the air rectifying member 47.

  As shown in FIG. 2, the air that has flowed into the valve 49 is discharged out of the return filter 1 through the air vent hole 41e. Since the float 48 is provided inside the valve 49, even if hydraulic fluid flows into the valve 49, the hydraulic fluid does not leak out of the return filter 1 because the float 48 contacts the recess 41 d.

  Even if the hydraulic oil passes through the valve 49, the hydraulic oil passes through the air vent holes 41 e and 41 f, the air vent hole 13 a, and a hole (not shown) formed in the upper surface 101 a of the tank body 101. Returned to the inside.

  According to the present embodiment, since the hydraulic oil flows into the space S1 from the tangential direction at an arbitrary point on the side surface 11a, the hydraulic oil that has flowed into the space S1 can be swirled. In particular, since the flow path of the hydraulic oil is narrowed by the convex portion 32a, the hydraulic oil can be turned more reliably.

  Further, according to the present embodiment, the ribs 32c and 32d substantially along the axis A are disposed between the filter element 20 and the case body 11 in plan view, below the inflow pipe 14 in the height direction, and on the plate. Therefore, it is possible to prevent the swirling flow from being generated in the vicinity of the filter element 20 (it is difficult to swirl). Therefore, it is possible to prevent the filter element 20 from rotating due to the flow of hydraulic oil.

  In addition, according to the present embodiment, since the air rectifying member 47 is provided under the valve 49, air easily flows from the space S1 toward the valve 49. Therefore, air is easily discharged out of the return filter 1.

  In the present embodiment, the rectifying unit 30 includes the plate-like member 31 and the rectifying member 32, but the plate-like member 31 is not essential. However, in order to increase the rectifying effect, it is desirable to provide the plate member 31. Moreover, although the rectifying member 32 has the ribs 32c and 32d, the position, shape, and number of ribs are not limited thereto.

  In the present embodiment, the outflow portion 50 is inserted into the opening 23 a and penetrates the bottom surface 11 c, so that one end is provided in the hollow portion of the filter element 20 and the other end is outside the filter case 10. Although provided, the form of the outflow part 50 is not restricted to this. For example, the outflow part 50 may be substantially L-shaped in a side view, and one end may be inserted into the opening 23a and the other end may be provided on the side surface 11a.

<Second Embodiment>
In the first embodiment of the present invention, the flow direction of the hydraulic oil is changed using the rectifying unit 30, but the method of changing the flow direction of the hydraulic oil is not limited to this.

  The 2nd Embodiment of this invention is a form which forms the rectification | straightening part which changes the direction of the flow of hydraulic fluid in a case. Hereinafter, the return filter 2 according to the second embodiment will be described. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 9 is a cross-sectional view schematically showing the return filter 2 (however, hatching indicating the cross section is omitted). The return filter 2 mainly includes a filter case 10 </ b> A, a filter element 20, an outflow portion 50, and a lid member 60.

  The filter case 10 </ b> A mainly includes a case main body 11, a mounting member 12, and a rib 15. The ribs 15 are substantially plate-shaped, and a plurality (four in this embodiment) are provided on the inner peripheral surface of the case main body 11 so as to substantially follow the axis A. The plurality of ribs 15 correspond to a rectifying unit. The position of the rib 15 in plan view is between the filter element 20 and the case body 11. The height of the rib 15 is a position below the inflow pipe 14 and a position overlapping the plate 24.

  In the present embodiment, the ribs 15 are provided at four locations, but the number of the ribs 15 is not limited to four as long as it is plural. The shape of the rib 15 is not limited to this, and the rib 15 may be in contact with the bottom surface 11c, for example.

  The lid member 60 is a substantially plate-like member that is made of metal and covers the upper opening end of the filter case 10A. The lid member 60 is detachably attached to the filter case 10A.

  The lid member 60 mainly has a plate-like portion 60a and a tubular portion 60b. The cylindrical part 60b is a substantially cylindrical member, and is formed on the lower surface 60c of the plate-like part 60a. The cylindrical part 60 b is inserted into the case main body 11.

  A substantially cylindrical mounting member 53 is provided on the lower surface 60c. When the lid member 60 and the attachment member 53 are removed from the filter case 10A, the filter element 20 can be extracted from the upper opening end of the filter case 10A. When the filter element 20 is inserted from the upper opening end of the filter case 10 </ b> A and the lid member 60 and the attachment member 53 are attached to the filter case 10, the elastic member 52 provided below the attachment member 53 is attached to the filter element 20. As a result, a downward force is urged, whereby the filter element 20 is fixed inside the case body 11.

  In addition, the form of the attachment member 53 is not restricted to this. For example, the attachment member 53 may be long, and the position in the height direction of the attachment member 53 may overlap the position in the height direction of the inflow pipe 14.

  A substantially cylindrical recess 60d is formed on the lower surface 60c. A substantially cylindrical mounting member 62 is inserted into the recess 60d. A plate-like member 61 having a hole 61a formed at substantially the center is provided below the recess 60d. The recess 60 d has the same configuration as the recess 41 c, the mounting member 62 has the same configuration as the mounting member 46, and the plate-like member 61 has the same configuration as the plate-like member 45.

  The concave portion 62a formed in the attachment member 62, the concave portion 60e formed in the lid member 60, and the float 48 inserted into the space formed by the concave portion 62a and the concave portion 60e constitute the valve 65. The concave portion 46a has the same configuration as the concave portion 46a, the concave portion 62a has the same configuration as the concave portion 41d, and the valve 65 has the same configuration as the valve 49.

  A substantially cylindrical recess 62b (see FIG. 10) communicating with the recess 62a is formed below the attachment member 62. The recess 62 b corresponds to a recess formed on the lower surface of the lid member 60. The recess 62b has the same configuration as the recess 46b. An air rectifying member 63 is provided in the recess 62b.

  10 is a cross-sectional view taken along the line CC of FIG. The air rectifying member 63 has a substantially plate-like fin 63a. The number of fins 63a is four, and a wide surface is provided substantially parallel to the z direction (axis A) and protruding in the circumferential direction. However, the number of fins 63a is not limited to this.

  The outer peripheral part of the fin 63a substantially contacts the inner peripheral surface of the concave part 62b. Therefore, the space between the fins 63a and the fins 63a becomes a passage for air.

  Next, the function of the return filter 2 configured as described above will be described. In FIG. 9, a solid line arrow indicates the flow of hydraulic oil, and a two-dot chain line arrow indicates the flow of air.

  During the operation of the hydraulic device, hydraulic oil flows in the hydraulic circuit. As shown in FIG. 2, the hydraulic oil flows into the space S1 through the inflow pipe 14 and the opening 11b, and turns inside the space S1.

  The hydraulic oil flows downward while turning. At this time, the hydraulic oil collides with the rib 15, whereby the flow of the hydraulic oil is changed from the swirling flow to the downward flow. Since the hydraulic oil does not swirl along the outer peripheral surface of the filter element 20 (or the swirl flow is weak), the filter element 20 does not rotate.

  The hydraulic oil that has passed through the space between the ribs 15 and has flowed between the filter element 20 and the case main body 11 passes through the filter medium 22 and flows into the inner cylinder 21 (space S2).

  The filtered hydraulic oil is discharged from the return filter 2 from the hollow portion of the inner cylinder 21 through the outflow portion 50 and stored in the hydraulic oil tank 100.

  Since the hydraulic oil flowing into the space S1 is swirling, air contained in the liquid gathers and becomes large bubbles, is removed from the hydraulic oil, and rises above the case body 11. Thereafter, the air flows into the recess 62b through the hole 61a.

  The air that has flowed into the recess 62b flows upward between the air rectifying member 63 and the recess 62b. When the air flows along the fins 63a, the air flow becomes in the + z direction, and the air easily flows from the space S1 toward the valve 65. The air flowing into the valve 65 is discharged out of the return filter 2 through the air vent hole 60f.

  According to the present embodiment, it is possible to prevent the swirling flow from being generated in the vicinity of the filter element 20 while generating the swirling flow in the hydraulic oil with a simple structure. In particular, by forming the ribs 15 directly on the case body 11, a simple configuration can be obtained.

  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 design changes and the like within a scope not departing from the gist of the present invention are included. . 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. In addition, a part of the configuration of the embodiment can be replaced with the configuration of the other embodiment, and other configurations can be added to, deleted from, or replaced with the configuration of the embodiment.

  Further, in the present invention, “substantially” is a concept including not only a case where they are exactly the same but also errors and deformations that do not lose the identity. For example, “substantially orthogonal” is not limited to being strictly orthogonal, and is a concept including an error of, for example, several degrees. Further, for example, when simply expressing as orthogonal, parallel, coincidence, etc., not only strictly orthogonal, parallel, coincidence, etc. but also cases of substantially parallel, substantially orthogonal, substantially coincidence, etc. are included.

  Further, in the present invention, “near” means including a region in a certain range (which can be arbitrarily determined) near a reference position. For example, in the case of the vicinity of the end, it is a concept indicating that the region is in a certain range near the end and may or may not include the end.

1, 2: Return filter 10, 10A: Filter case 11: Case main body 11a: Side surface 11b: Opening portion 11c: Bottom surface 12, 13: Mounting member 13a: Air vent hole 14: Inflow pipe 15: Rib 20: Filter element 21: Inside Tube 21a: Hole 22: Filter medium 23, 24: Plate 23a: Opening 25, 26: Valve 30: Rectifier 31: Plate member 31a, 31b: Hole 31c: Lower surface 32: Rectifier member 32a: Protrusion 32b: Plate Portions 32c, 32d: Ribs 32e, 32f: Upper surface 32g: Hole 40: Lid member 41: Lid body 41a: Plate-like portion 41b: Tubular portion 41c, 41d: Recessed portion 41e, 41f: Air vent hole 42: Tubular member 45: Plate-like member 45a: Hole 46: Mounting member 46a, 46b: Concave portion 46c: Concave portion 47: Air rectifying portion 47a, 47b: Fin 47c : Convex part 48: float 49: valve 50: outflow part 50a: holes 51 and 52: elastic member 53: mounting member 60: lid member 60a: plate-like part 60b: cylindrical part 60c: lower surface 60d and 60e: concave part 60f: Air vent hole 61: Plate member 61a: Recess 62: Mounting member 62a, 62b: Recess 63: Air rectifier 63a: Fin 65: Valve 100: Hydraulic oil tank 101: Tank body 101a: Upper surface 101b: Hole

Claims (5)

A substantially cylindrical bottomed filter case;
A lid member covering the open end of the upper part of the filter case;
A filter element provided inside the filter case, the filter element having a substantially cylindrical filter medium, a first plate member covering an upper end of the filter medium, and a second plate member covering a lower end of the filter medium. Elements,
An inflow pipe which is provided on a side surface of the filter case and causes a liquid to flow into the filter case from a tangential direction at an arbitrary point on the side surface of the filter case, thereby generating a swirling flow in the inflowed liquid; An inflow pipe provided between the lid member and the filter element in the vertical direction;
Ribs provided substantially along the center axis of the filter case and the filter element, the position in plan view is between the filter element and the filter case, and the position in the height direction is the inflow pipe A rectifying unit having a plurality of ribs at a lower position and a position overlapping the first plate member;
An outflow portion having a substantially cylindrical shape penetrating the bottom surface of the second plate-shaped member, wherein one end is provided in the hollow portion of the filter medium, and the other end is provided outside the filter case;
A filter device comprising: The filter device according to claim 1,
The rectifying part has a substantially disk-shaped plate-like part in which the rib is formed on the periphery, and a convex part protruding upward from the plate-like part,
The filter device, wherein a position in the height direction of the convex portion and a position in the height direction of the inflow pipe overlap. The filter device according to claim 1 or 2,
A substantially cylindrical recess is formed on the lower surface of the lid member,
Inside the recess, a rectifying member for air is provided,
The air rectifying member has a plurality of first fins whose wide surfaces are substantially parallel to the central axis, and the plurality of first fins are provided so as to protrude in a radial direction,
A filter device, wherein a valve and an air vent hole are provided inside the lid member above the air rectifying member. The filter device according to claim 3,
The air rectifying member is provided with a second fin having a wide surface substantially orthogonal to the central axis between the adjacent first fins,
In the plan view, the outer periphery of the second fin is smaller than the outer periphery of the first fin. The filter device according to claim 3 or 4,
On the lower surface of the lid member, a substantially cylindrical tubular portion having a substantially truncated cone side surface is provided such that the upper surface with a small area is positioned on the upper side and the bottom surface with a large area is positioned on the lower side,
The said recessed part is formed in the area | region enclosed by the said cylindrical part, The filter apparatus characterized by the above-mentioned.

Images