Box device

Abstract

The present invention relates to a box device. The present invention enables the replacement of a filter element from the side of the box. Inside the box with a cavity inside, a reflux filter and a coarse filter are horizontally arranged. The box has two substantially parallel sides, namely a first box side and a second box side. The reflux filter is arranged in the box through an insertion hole formed in the first box side. One end of the coarse filter is arranged at the outflow part, and the other end is arranged at the second box side. The outflow part is arranged on the bottom surface of the filter housing.

Description

Technical Field

[0001] The present invention relates to a box device. Background Art

[0002] Patent Document 1 discloses a box device. When a filter cartridge including a filter medium is inserted into the inside of a filter housing, a first hole and a second hole formed in the filter cartridge are respectively connected to a third hole and a fourth hole formed in the filter housing, and a state is formed in which a first lid member to a fourth lid member do not cover the first hole to the fourth hole, and the internal space of the filter cartridge communicates with the internal space of the filter housing.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-196552 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the invention described in Patent Document 1, when replacing the filter cartridge, it is necessary to take out and insert the filter cartridge from the upper opening of the box. At this time, the operator must climb to a high place to perform the replacement operation, which may cause problems in terms of the safety of the operator and the operability of the replacement operation.

[0008] The present invention has been made in view of such a situation, and an object thereof is to provide a box device capable of replacing a filter element from the side of the box.

[0009] Means for Solving the Problems

[0010] In order to solve the above problems, the box device of the present invention, for example, includes: a box with a cavity inside; a reflux filter horizontally arranged inside the box, and having a filter housing in a substantially bottomed cylindrical shape with one end being an opening, a filter head arranged inside the filter housing, and a filter element having a substantially cylindrical filter medium, a valve bearing member arranged on an end surface of the filter medium, and a valve arranged on the valve bearing member; a cover body arranged on the reflux filter so as to cover the opening; and a coarse filter horizontally arranged inside the box and arranged on the reflux filter, and is characterized in that: the box has two substantially parallel side surfaces, namely a first box side surface and a second box side surface, an insertion hole is formed on the first box side surface, the filter housing is arranged on the first box side surface and is inserted into the inside of the box from the insertion hole, an outflow portion for allowing the liquid that has passed through the filter medium to flow out into the box is arranged on a bottom surface of the filter housing, one end of the coarse filter is arranged at the outflow portion, and the other end is arranged at the second box side surface, the valve bearing member has a substantially plate-shaped plate portion, the plate portion is provided with a substantially cylindrical first hole for allowing oil to flow into the filter medium and a second hole for allowing the oil filtered by the filter medium, i.e., the filtered oil, to flow out, the valve has: a first valve having a first cover member and a first compression spring, the first cover member has a first insertion portion inserted into the inside of the first hole to block the first hole, and the first compression spring arranges the first cover member at a position where the first insertion portion blocks the first hole; and a second valve having a second cover member and a second compression spring, the second cover member has a second insertion portion inserted into the inside of the second hole to block the second hole, and the second compression spring arranges the second cover member at a position where the second insertion portion blocks the second hole, the filter head is provided with: a plate formed with a third hole and a fourth hole; a third cover member having a third insertion portion capable of being inserted into the inside of the third hole; a fourth cover member having a fourth insertion portion capable of being inserted into the inside of the fourth hole;and a third compression spring that applies a force to the plate in a direction toward the opening portion to dispose the plate at a position where the third cover member closes the third hole and the fourth cover member closes the fourth hole. When the filter element is inserted into the interior of the filter housing through the opening portion, a first surface of the first cover member abuts against a third surface of the third cover member, a second surface of the second cover member abuts against a fourth surface of the fourth cover member, and the plate abuts against the valve carrier member. When the filter element is pressed into the interior of the filter housing, the valve carrier member presses the plate against the action of the third compression spring, the third cover member presses the first cover member against the action of the first compression spring, and the fourth cover member presses the second cover member against the action of the second compression spring. When the filter element is inserted to the end of the filter housing, the first hole communicates with the third hole, and the second hole communicates with the fourth hole, so that the internal space of the filter element communicates with the internal space of the filter head.;

[0011] In the case device according to the present invention, a return filter and a coarse filter are horizontally provided inside a case having a cavity inside. The case has two substantially parallel side surfaces, namely a case first side surface and a case second side surface, and the return filter is provided in the case through an insertion hole formed in the case first side surface. One end of the coarse filter is provided at an outflow portion, and the other end is provided at the case second side surface, and the outflow portion is provided on the bottom surface of the filter housing in the case. Thus, by integrating the return filter and the coarse filter and horizontally providing them inside the case, the filter element can be replaced from the side surface of the case.

[0012] In addition, since the return filter and the coarse filter are sandwiched between two parallel side surfaces of the case, even if the return filter and the coarse filter are horizontal, the return filter and the coarse filter can be firmly fixed inside the case.

[0013] Further, when the filter element is inserted into the interior of the filter housing through the opening portion, the first surface of the first cover member on the filter element side and the second surface of the second cover member respectively abut against the third surface of the third cover member on the filter head side and the fourth surface of the fourth cover member, and the plate abuts against the valve carrier member. When the filter element is pressed into the interior of the filter housing, the valve carrier member presses the plate against the force of the third compression spring, the third cover member presses the first cover member against the force of the first compression spring to open the first hole and the third hole, and the fourth cover member presses the second cover member against the force of the second compression spring to open the second hole and the fourth hole. Further, when the filter element is pressed into the interior of the filter housing, the first hole communicates with the third hole, and the second hole communicates with the fourth hole, so that the internal space of the filter element communicates with the internal space of the filter head. That is to say, only when the filter element is installed on the filter head, the internal space of the filter element communicates with the internal space of the filter head. Therefore, even if the return flow filter is arranged horizontally, it is possible to prevent the liquid inside the tank and the liquid inside the filter element from leaking to the outside when replacing the filter element.

[0014] Here, it is also possible that the return flow filter has a tubular member that communicates the outside of the tank with the interior of the filter housing. The tank has a third side surface of the tank that is adjacent to the first side surface and the second side surface of the tank. Holes for inserting the tubular member are respectively provided on the third side surface of the tank and the filter housing. Thereby, it is possible to prevent the return flow filter and the coarse filter from vibrating along with the vibration of the tank device, and further improve the strength of the tank device.

[0015] Here, it is also possible that the return flow filter and the coarse filter are arranged near the bottom surface of the tank. Thereby, it is possible to lower the installation position of the return flow filter and improve the safety of the replacement operation.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to replace the filter element from the side of the tank. Brief Description of the Drawings

[0018] Figure 1 It is an exploded perspective view showing an overview of a tank device 1 according to an embodiment of the present invention.

[0019] Figure 2 It is an exploded perspective view showing an overview of a part of the tank device 1, namely, a return flow filter 3 and a coarse filter 4.

[0020] Figure 3 It is a cross-sectional view showing an overview of the tank device 1.

[0021] Figure 4 It is a partially enlarged cross-sectional view of the return flow filter 3 in a state before the filter element 20 is installed on the filter head 32.

[0022] Figure 5 This is a partially enlarged cross-sectional view of the return filter 3 with the filter element 20 installed on the filter head 32.

[0023] Figure 6 This is a diagram schematically showing the replacement situation of the filter element 20.

[0024] Figure 7 This is a diagram schematically showing the replacement situation of the coarse filter 4.

[0025] Explanation of Reference Numerals

[0026] 1: Tank device; 2: Tank; 2a, 2c, 2d: Sides; 2b: Insertion hole; 2e: Bottom surface; 2f: Upper surface; 2g: Outlet; 2h: Hole; 2i: Flange; 3: Return filter; 4: Coarse filter; 4a: Filter medium; 4b: Upper end support member; 4c: Lower end support member; 4d: Through hole; 5: Cover body; 20: Filter element; 21: Filter medium; 21a: Plate; 22: Handle part; 22a: Gripping part; 22b: Cylindrical part; 23: Outer cylinder; 24: Valve carrier member; 24a: Inner cylinder part; 24b: Plate-like part; 24c: Outer cylinder part; 24d: Groove; 24e, 24f: Holes; 24g: Protrusion; 25: Inner cylinder; 26: Measuring part; 30: Housing; 31: Filter housing; 31a: Flange part; 31b: Opening; 31c: Bottom surface; 31d: Hole; 32: Filter head; 33: Tubular member; 33b: Opening; 34: Outlet pipe; 35: Plate; 35a: Main body part; 35b: Cylindrical part; 35c: Groove; 35d, 35e, 35g: Holes; 35f: Cylindrical part; 36: Compression spring; 37: Main body part; 37a: Inlet; 37b: Hole; 37e: Shaft; 37f: Cylindrical part; 38: Back pressure valve; 38a: Elastic member; 38b: Fixed part; 38c: Moving member; 40: Valve; 41: Cover member; 41a: Insertion part; 41b: Flange part; 41c: Groove; 41d: Back surface; 41e: Protrusion; 42: Compression spring; 45: Cover member; 45a: Insertion part; 45b: Surface; 45c: Groove; 45d: Protruding part; 46: Valve; 48: Valve; 50, 51, 52, 55, 56, 57, 58: Sealing members. Detailed Embodiments

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The tank device of the present invention is provided in construction machinery such as a hydraulic excavator.

[0028] Construction machinery mainly includes: a lower traveling body having crawlers; an upper revolving body provided on the upper side of the lower traveling body; an operation unit including an arm, a boom mounted at the front end of the arm, and a bucket mounted at the front end of the boom; a hydraulic circuit including hydraulic cylinders, tanks, etc. for driving the operation unit; and a cab, etc. The operation unit, the hydraulic circuit, the cab, etc. are provided on the upper revolving body. The tank device of the present invention is a part of the hydraulic circuit.

[0029] Hereinafter, the tank device of the present invention will be described as a device for filtering hydraulic oil used in the hydraulic circuit, but the liquid to be filtered is not limited to hydraulic oil. The tank device can filter various liquids such as oil and water.

[0030] Figure 1 Fig. is an exploded perspective view showing an overview of a tank device 1 according to an embodiment of the present invention. Figure 2 Fig. is an exploded perspective view showing an overview of a part of the tank device 1, namely, a return filter 3, a coarse filter 4, and a cover body 5.

[0031] The tank device 1 mainly includes a tank 2, a return filter 3, a coarse filter 4, and a cover body 5.

[0032] The inside of the tank 2 is a cavity for storing hydraulic oil. The tank 2 mainly has side surfaces 2a, 2c, 2d, a bottom surface 2e, and a stepped upper surface 2f. However, the shape of the tank 2 is not limited thereto.

[0033] An insertion hole 2b is provided on the side surface 2a. The insertion hole 2b is formed near the bottom surface 2e.

[0034] A return filter 3 and a coarse filter 4 are provided inside the tank 2. The return filter 3 and the coarse filter 4 are integrated and are provided inside the tank 2 through an insertion hole 2b formed on the side surface 2a of the tank 2.

[0035] Since the insertion hole 2b is formed near the bottom surface 2e, the return filter 3 and the coarse filter 4 are horizontally arranged near the bottom surface 2e. In addition, in the present invention, the horizontal direction includes a state where the central axis is along the horizontal direction and a state where the central axis is slightly inclined (for example, about 10 degrees) with respect to the horizontal direction.

[0036] The coarse filter 4 and the housing 30 are inserted into the inside of the tank 2 through the insertion hole 2b, and the flange portion 31a (described in detail later) abuts and is fixed on the side surface 2a, thereby setting the return filter 3 and the coarse filter 4 inside the tank 2.

[0037] The return filter 3 mainly includes a filter element 20 and a housing 30. One end face of the housing 30 is open, and this opening is the opening portion 31b. After using for a predetermined time, the used filter element 20 is taken out from the housing 30 via the opening portion 31b. In addition, a new filter element 20 is provided inside the housing 30 via the opening portion 31b. A flange portion 31a for mounting the housing 30 to the side surface 2a is provided around the opening portion 31b. The return filter 3 will be described in detail later.

[0038] In order to prevent foreign matter from entering the hydraulic pump, a coarse filter 4 is provided inside the tank 2. The hydraulic oil stored in the tank 2 is sucked by a hydraulic pump (not shown) via the coarse filter 4 and supplied to the hydraulic device again. The coarse filter 4 mainly includes a filter medium 4a, an upper end support member 4b, and a lower end support member 4c. The filter medium 4a is, for example, a plate-like member made of metal formed with a plurality of holes, and is formed into a substantially cylindrical shape by connecting both ends and rolling into a cylindrical shape. In addition, the form of the filter medium 4a is not limited to this. The upper end support member 4b is a plate-like member covering the upper end of the filter medium 4a, and the lower end support member 4c is a plate-like member covering the lower end of the filter medium 4a.

[0039] The cover body 5 is provided on the return filter 3 and the tank 2 so as to cover the opening portion 31b. In addition, the cover body 5 may also be provided only on the return filter 3.

[0040] Figure 3 It is a cross-sectional view showing an overview of the tank device 1. Figure 3 It is a view obtained by cutting the tank device 1 on a plane passing through the central axes ax1 and ax2 of the return filter 3 and the coarse filter 4 and along the xy plane. In Figure 3 the hatching indicating the cross-section is omitted.

[0041] The return filter 3 is provided inside the tank 2 by fixing the flange portion 31a to the side surface 2a. The coarse filter 4 is positioned and fixed to the tank 2 by inserting the outlet 2g formed on the side surface 2d into a through hole 4d formed in a substantially central portion of the lower end support member 4c. A sealing member (such as an O-ring) 58 is provided between the through hole 4d and the outlet 2g to prevent leakage of hydraulic oil.

[0042] Although the central axis ax1 of the return filter 3 substantially coincides with the central axis ax2 of the coarse filter 4 in the embodiment of the present invention, it is sufficient that the return filter 3 and the coarse filter 4 coincide when viewed along the central axes ax1 and ax2. Thus, the return filter 3 and the coarse filter 4 can be provided in a narrow space, and the size of the tank 2 can be reduced.

[0043] The filter element 20 mainly includes a filter medium 21, a handle portion 22, an outer cylinder 23, a valve carrier member 24, and an inner cylinder 25.

[0044] The filter medium 21 has a substantially hollow cylindrical shape with a thickness in the radial direction. The filter medium 21 is formed by pleating and folding a sheet-like filter paper made of synthetic resin, paper, etc., and connecting and rolling both ends of the pleated and folded filter paper into a cylindrical shape.

[0045] The outer cylinder 23 and the inner cylinder 25 are members having a substantially hollow cylindrical shape formed of a material with high corrosion resistance (resin or metal). Holes for hydraulic oil to pass through are formed on the entire surface of the inner cylinder 25. The outer cylinder 23 is provided outside the filter medium 21, and the inner cylinder 25 is provided inside the filter medium 21. In addition, the inner cylinder 25 is not essential.

[0046] At one end of the filter medium 21, the outer cylinder 23, and the inner cylinder 25 ( Figure 3 the right end, +y side end in the figure) a handle portion 22 is provided. The handle portion 22 is fixed to the filter medium 21, the outer cylinder 23, and the inner cylinder 25 so as to cover the upper ends of the filter medium 21, the outer cylinder 23, and the inner cylinder 25. A gripping portion 22a, which is a member for the operator to grip the filter element 20, is provided on the handle portion 22. In addition, the handle portion 22 has a cylindrical portion 22b that fits into the inner peripheral surface of the inner cylinder 25 and serves as a cover for the filter element 20.

[0047] In addition, a measuring portion 26 such as a differential pressure sensor and a thermometer is provided on the handle portion 22. The differential pressure sensor detects the pressure difference (differential pressure) between the inflow space S3 and the outflow space S4.

[0048] At the other end of the filter medium 21, the outer cylinder 23, and the inner cylinder 25 ( Figure 3 the left end, -y side end in the figure) a valve carrier member 24 is provided. The valve carrier member 24 is formed of a material with high corrosion resistance (resin or metal). The valve carrier member 24 will be described in detail later.

[0049] The housing 30 mainly includes a filter housing 31 in which the filter element 20 is disposed, a filter head 32 disposed inside the filter housing 31, an outflow pipe 34 disposed on the filter housing 31, and a back pressure valve 38.

[0050] The filter housing 31 is a member having a substantially bottomed cylindrical shape and is formed of metal or resin. A flange portion 31a and an opening portion 31b ( Figure 3 not shown in the figure) are provided at the +y side end of the filter housing 31. After the filter element 20 is inserted into the filter housing 31 from the opening portion 31b, the opening portion 31b is covered by a cover body 5.

[0051] A bottom surface 31c is provided at the end of the filter housing 31 on the side opposite to the opening portion 33b (-y side). In addition, holes 31d are formed on the side surface of the filter housing 31.

[0052] In addition, in the present embodiment, the filter housing 31 is formed by combining a substantially cylindrical member and a bottomed substantially cylindrical member, but the structure of the filter housing 31 is not limited thereto.

[0053] A filter head 32 is provided inside the filter housing 31, and a valve carrier member 24 for mounting the filter element 20 is installed thereon.

[0054] The filter head 32 mainly includes a plate 35, a compression spring 36, and a main body portion 37. The plate 35 is provided on the main body portion 37 via the compression spring 36.

[0055] A sealing member 50 (such as an O-ring) is provided between the filter housing 31 and the main body portion 37. Sealing is performed by the sealing member 50 to prevent liquid from leaking to the outside between the filter housing 31 and the main body portion 37. The filter head 32 will be described in detail later.

[0056] The tubular member 33 is a substantially cylindrical member that communicates the outside of the tank 2 with the inside of the filter housing 31. An inlet 37a for guiding the oil before filtration to the inflow space S1 is provided on the side surface of the main body portion 37. The inlet 37a is an opening at one end of a hole 37b provided in the main body portion 37. The tubular member 33 is inserted into the hole 31d and the inlet 37a. In addition, a hole 2h is provided on the side surface 2c of the tank 2 adjacent to the side surfaces 2a and 2d, and the tubular member 33 is inserted into the hole 2h. Thus, the hydraulic oil before filtration is guided to the inflow space S1 via the tubular member 33.

[0057] The outflow pipe 34 is substantially cylindrical (here, substantially cylindrical), and is provided on the bottom surface 31c. The outflow pipe 34 communicates with the outflow space S2 via the filter head 32.

[0058] A back pressure valve 38 is provided at the front end (-y side, the side opposite to the bottom surface 31c side) of the outflow pipe 34. The outflow pipe 34 and the back pressure valve 38 constitute an outflow portion for allowing the filtered hydraulic oil that has passed through the filter medium 21 to flow out to the tank 2. The back pressure valve 38 mainly includes an elastic member 38a, a fixing portion 38b provided at one end of the elastic member 38a, and a moving member 38c provided at the other end of the elastic member 38a. The fixing portion 38b abuts against the coarse filter 4.

[0059] As the pressure inside the filter housing 31 rises, the moving member 38c moves from the closed state ( Figure 3 the state shown) where the moving member 38c abuts against the outflow pipe 34 to the open state where the moving member 38c does not abut against the outflow pipe 34 against the acting force of the elastic member 38a.

[0060] When the operation of the engine of a work machine or the like stops, the filter housing 31 does not contain hydraulic oil. Therefore, the backpressure valve 38 is in a closed state. When the engine of the work machine runs and the flow rate of the hydraulic oil increases, the inside of the filter housing 31 is filled with the hydraulic oil, and the pressure inside the filter housing 31 becomes large enough. Therefore, the hydraulic oil pushes the moving member 38c downward against the acting force of the elastic member 38a, and the backpressure valve 38 becomes an open state. As a result, the filtered hydraulic oil flows out from the outflow pipe 34.

[0061] In addition, a valve 48 is provided on the main body portion 37. The outflow pipe 34 is provided to cover the valve 48. The valve 48 opens and closes according to the difference between the pressure in the inflow space S1 and the pressure in the external space of the housing 30. Since the valve 48 is well-known, its detailed description is omitted.

[0062] In addition, an exhaust valve (not shown) may be provided on the main body portion 37. The exhaust valve opens when air remains inside the main body portion 37 and discharges the air into the tank 2. In the present embodiment, since the return filter 3 is horizontally provided, the exhaust valve is provided on the upper side (+z side) of the side surface of the main body portion 37.

[0063] Next, the valve carrier member 24 and the filter head 32 will be described. Figure 4 FIG. is a partially enlarged cross-sectional view of the return filter 3 in a state before the filter element 20 is installed in the filter head 32. In Figure 4 the cross-hatching indicating the cross-section is omitted.

[0064] The valve carrier member 24 mainly includes an inner cylinder portion 24a, a plate-like portion 24b, and an outer cylinder portion 24c. The front end of the inner cylinder portion 24a is fitted to the inner peripheral surface of a plate 21a provided at the end of the filter medium 21, and the outer cylinder 23 is fitted to a groove 24d formed at the front end of the outer cylinder portion 24c, so that the filter medium 21, the outer cylinder 23, and the valve carrier member 24 are integrated.

[0065] The plate-like portion 24b has a substantially circular plate shape and is formed with substantially cylindrical holes 24e and 24f. The hole 24e is an oil inlet for allowing unfiltered dirty oil (oil before filtration) to flow into the filter medium 21, and the hole 24f is an oil outlet for allowing the oil filtered by the filter medium 21 (filtered oil) to flow out. The hole 24e is connected to the inflow space S3, and the hole 24f is connected to the outflow space S4.

[0066] In addition, a valve 40 is provided on the valve carrier member 24. The valve 40 includes a lid member 41 that closes the holes 24e and 24f by being inserted into the inside of the holes 24e and 24f, and a compression spring 42 that applies a force to the lid member 41.

[0067] The lid member 41 has an insertion portion 41a with a substantially circular plate shape that is inserted into the insertion holes 24e and 24f, and a flange portion 41b provided on the surface of the insertion portion 41a (the +z side surface). The flange portion 41b is plate-shaped and has an outer diameter larger than the inner diameter of the holes 24e and 24f.

[0068] The insertion portion 41a has a substantially cylindrical shape and an outer diameter substantially the same as the inner diameter of the holes 24e and 24f. A groove 41c is formed on the outer periphery of the insertion portion 41a, and a sealing member (such as an O-ring) 55 is provided in the groove 41c. The back surface (-z side surface) 41d of the insertion portion 41a is integrally formed in a concave shape of a substantially truncated cone.

[0069] The compression spring 42 is, for example, a helical spring. One end of the compression spring 42 is provided on the inner side of the bottom surface of the inner cylinder portion 24a (the projection portion 24g), and the other end is provided on the lid member 41 (the projection portion 41e formed on the surface of the flange portion 41b). Therefore, the compression spring 42 applies a force in the -y direction to the lid member 41.

[0070] When a force in the -y direction is applied by the compression spring 42, the insertion portion 41a is inserted into the hole 24e or the hole 24f, and the lid member 41 is disposed at a position where the flange portion 41b abuts against the plate-like portion 24b, so that the lid member 41 closes the hole 24e or the hole 24f. This state is the state where the valve 40 is closed.

[0071] The main body portion 37 divides the inside of the filter housing 31 into an inflow space S1 for the oil before filtration to flow into the filter element 20 and an outflow space S2 for the filtered oil flowing out from the filter element 20 to flow out to the outside of the tank device 1.

[0072] One end of the compression spring 36 is provided on the back surface of the plate 35, and the other end is provided on the surface of the main body portion 37, applying an upward (+y direction) force to the plate 35. Therefore, the plate 35 is disposed at a position away from the main body portion 37 by the natural length of the compression spring 36.

[0073] The plate 35 is integrally formed in a substantially circular plate shape and has a substantially plate-like main body portion 35a and a cylindrical portion 35b protruding upward from the main body portion 35a. A groove 35c is formed on the outer peripheral surface of the main body portion 35a, and a sealing member 51 (such as an O-ring) is provided in the groove 35c. Sealing is performed by the sealing member 51 to prevent liquid from leaking to the outside between the filter housing 31 and the main body portion 35a.

[0074] Holes 35d and 35e are formed in the plate 35 and penetrate the main body portion 35a in the plate thickness direction. The hole 35d is an oil inlet for the oil before filtration to pass through, and the hole 35e is an oil outlet for the filtered oil to pass through. The diameter of the hole 35d is substantially the same as the diameter of the hole 24e, and the diameter of the hole 35e is substantially the same as the diameter of the hole 24f.

[0075] A cylindrical portion 35f protruding in the -y direction is formed on the main body portion 35a. The hollow portion of the cylindrical portion 35f communicates with the hole 35d. The front end of the cylindrical portion 35f is slidably disposed inside a cylindrical portion 37f formed on the upper surface of the main body portion 37. The internal space of the cylindrical portion 37f and the cylindrical portion 35f is an inflow space S1, and the external space of the cylindrical portion 37f and the cylindrical portion 35f is an outflow space S2. The cylindrical portion 35f is thinner than the hole 35d.

[0076] A sealing member 57 is provided on the outer periphery of the cylindrical portion 35f, which seals to prevent liquid from leaking to the outside between the cylindrical portion 37f and the cylindrical portion 35f.

[0077] In addition, a hole 35g thinner than the hole 35e is formed on the main body portion 35 as a lower hole of the hole 35e. The diameter of the hole 35g is thinner than the diameter of the cylindrical portion 35f.

[0078] Cover members 45 are respectively provided on the holes 35d, 35e. The cover member 45 is fixed to the front end of a shaft 37e provided on the main body portion 37.

[0079] The cover member 45 has a thick plate-shaped insertion portion 45a inserted into the inside of the holes 35d, 35e. The insertion portion 45a is generally cylindrical in shape, and the outer diameter is substantially the same as the inner diameter of the holes 35d, 35e. A groove 45c is formed on the outer periphery of the insertion portion 45a, and a sealing member (such as an O-ring) 56 is provided in the groove 45c.

[0080] A protruding portion 45d thinner than the insertion portion 45a is formed on the back surface of the insertion portion 45a. The shaft 37e is disposed on the protruding portion 45d. The protruding portion 45d is thinner than the cylindrical portion 35f and the hole 35g, and the insertion portion 45a is thicker than the cylindrical portion 35f and the hole 35g.

[0081] The cover member 45 and the compression spring 36 constitute a valve 46. The compression spring 36 pushes the plate 35 upward, thereby disposing the plate 35 at positions where the insertion portion 45a respectively blocks the holes 35d, 35e (the position where the protruding portion 45d is inserted into the cylindrical portion 35f or the hole 35g). This state is the state where the valve 46 is closed. In the state where the valve 46 is closed, sealing is performed by the sealing member 56 to prevent liquid from leaking between the insertion portion 45a and the holes 35d, 35e.

[0082] The entire surface 45b of the insertion portion 45a is a convex shape of a generally frustum of a cone. The surface 45b and the back surface 41d are complementary shapes.

[0083] Next, the assembly, part replacement, and operation of the thus formed box device 1 will be described.

[0084] Before using the box device 1, the filter element 20 is placed in the housing 30. Specifically, first, as Figure 1 、2 As shown, the operator inserts the filter element 20 through the opening 31b. When the filter element 20 is directly inserted to the end of the filter housing 31, as Figure 5 shown, the back surface 41d of the cover member 41 abuts against the front surface 45b of the cover member 45, and the outer periphery of the plate-like portion 24b (sealing member 52) fits into the cylindrical portion 35b.

[0085] Figure 5 FIG. is a partially enlarged cross-sectional view of the return filter 3 with the filter element 20 mounted on the filter head 32. In Figure 5 , some of the hatching indicating the cross-section is omitted.

[0086] The operator presses in the filter element 20, so that with the back surface 41d of the cover member 41 abutting against the front surface 45b of the cover member 45, the valve carrier member 24 presses the plate 35 against the force of the compression spring 36. As a result, the compression spring 36 is compressed, and the valve carrier member 24 and the plate 35 are pushed downward (moved in the -y direction, refer to the thick arrow in Figure 5 ).

[0087] As a result, the cover member 41 is pressed by the cover member 45 and is pushed upward against the force of the compression spring 42 (moved in the +y direction, refer to the thick arrow in Figure 5 ).

[0088] Since the back surface 41d of the cover member 41 and the front surface 45b of the cover member 45 are complementary in shape, the entire back surface 41d abuts against the entire front surface 45b. Therefore, the cover member 41 is reliably pushed upward against the force of the compression spring 42.

[0089] When the filter element 20 is mounted on the filter head 32, the plate-like portion 24b of the valve carrier member 24 fits into the cylindrical portion 35b of the plate 35, so that the hole 35d communicates with the hole 24e, and the hole 24f communicates with the hole 35e. Also, the cover member 41 is pushed upward, so that the holes 24e and 35d are opened, and the inflow space S1 communicates with the inflow space S3. Further, the holes 24f and 35e are opened, and the outflow space S2 communicates with the outflow space S4.

[0090] By placing the filter element 20 into the housing 30 and covering the opening 31b with the cover body 5, the tank device 1 can be used (refer to Figure 3 ).

[0091] As Figure 5 shown, the oil before filtration flowing in from the inlet 37a flows into the inflow space S3 of the filter element 20 through the inflow space S1. The oil before filtration guided to the inflow space S3 passes from the outside to the inside through the filter medium 21, is thus filtered, and is guided to the outflow space S4.

[0092] The filtered oil is discharged from the filter element 20 and directed to the outflow space S2. The filtered oil directed to the outflow space S2 is discharged to the outside of the tank device 1 through the outflow pipe 34.

[0093] Since the back surface 41d of the lid member 41 and the front surface 45b of the lid member 45 have complementary shapes, the entire back surface 41d abuts against the entire front surface 45b. Therefore, even when the tank device 1 is used, unfiltered oil and filtered oil (hereinafter referred to as hydraulic oil) will not adhere to the back surface 41d.

[0094] After using for a predetermined time, the used filter element 20 is removed from the housing 30 and replaced with a new filter element 20. Figure 6 It is a diagram schematically showing the replacement of the filter element 20.

[0095] For Figure 6 (A) the tank device 1 before the replacement operation shown, the operator Figure 6 (B) removes the lid 5 as shown, grasps the gripping portion 22a, and Figure 6 (C) pulls out the filter element 20 in the +y direction as shown. As a result, Figure 4 as shown, the compression spring 36 returns to its original length, the plate 35 and the valve carrier member 24 are pushed upward, the abutment between the back surface 41d of the lid member 41 and the front surface 45b of the lid member 45 is released, the fitting between the plate-like portion 24b and the cylindrical portion 35b is released, and the filter element 20 is separated from the housing 30.

[0096] When the plate 35 is pushed upward, Figure 4 as shown, the lid member 45 blocks the holes 35d, 35e (the valve 46 is closed). Since the valve 46 is closed, the hydraulic oil remaining inside the filter head 32 is sealed inside the filter head 32. In the present embodiment, the return filter 3 is provided horizontally, but by closing the valve 46 when replacing the filter element 20, leakage of hydraulic oil from the tank 2 is prevented.

[0097] At the same time, the lid member 41 is pushed downward by the compression spring 42. As a result, Figure 4 as shown, the lid member 41 blocks the holes 24e, 24f (the valve 40 is closed). Since the valve 40 is closed, the hydraulic oil remaining inside the filter element 20 is sealed inside the filter element 20 and does not flow out to the outside of the filter element 20.

[0098] In this way, after the filter element 20 is taken out to the outside of the housing 30, the new filter element 20 is placed in the housing 30 in the order already described.

[0099] In addition, in the tank device 1 of the present embodiment, the coarse filter 4 can also be replaced. Figure 7 It is a diagram schematically showing the replacement of the coarse filter 4.

[0100] For Figure 7 the tank device 1 before the replacement operation shown in (A), the operator Figure 7 removes the flange 2i from the side surface 2c and withdraws the tubular member 33 from the hole 2h as shown in (B). Then, the operator Figure 7 removes the cover body 5 as shown in (C), and Figure 7 pulls out the return filter 3 and the coarse filter 4 in the +y direction as shown in (D). Since the return filter 3 and the coarse filter 4 are integrated, the return filter 3 and the coarse filter 4 can be pulled out of the tank 2 by removing the flange portion 31a from the tank 2.

[0101] The operator Figure 7 disassembles the return filter 3 and the coarse filter 4 as shown in (E). Thus, the used coarse filter 4 is removed from the return filter 3.

[0102] Then, the operator sets a new coarse filter 4 on the return filter 3, inserts the return filter 3 and the coarse filter 4 into the inside of the tank 2 from the insertion hole 2b, fixes the flange portion 31a to the side surface 2a, and mounts the cover body 5 on the side surface 2a. In addition, the operator inserts the tubular member 33 from the hole 2h and mounts the flange 2i on the side surface 2c. Thus, the new coarse filter 4 is placed in the tank 2.

[0103] According to the present embodiment, valves 40 and 46 are provided to prevent the hydraulic oil inside the tank 2 and the hydraulic oil inside the filter element 20 from leaking when replacing the filter element 20. Therefore, the return filter 3 can be horizontally provided inside the tank 2. Therefore, when replacing the filter element 20, it is not necessary to withdraw the filter element 20 from above the tank 2. That is, the operator does not need to perform operations at a high place, and the safety of the replacement operation can be improved.

[0104] In addition, according to the present embodiment, since the return filter 3 and the coarse filter 4 are integrated and provided inside the tank 2, the tank 2 can be miniaturized. In addition, the coarse filter 4 is provided on the side surface 2d via the outflow port 2g, the return filter 3 is provided on the side surface 2a, and the return filter 3 and the coarse filter 4 are sandwiched between two parallel side surfaces 2a and 2d. Therefore, even if the return filter 3 and the coarse filter 4 are horizontal, the return filter 3 and the coarse filter 4 can be firmly fixed inside the tank 2.

[0105] Since construction machinery often travels on uneven roads, the tank device 1 also vibrates significantly up and down, just like construction machinery. For example, in a structure (so-called single support) where a coarse filter 4 is not provided at the front end of the return filter 3 and the return filter 3 is only installed on the side surface 2a, the front end of the return filter 3 moves in the vertical direction as the tank device 1 vibrates, and the strength of the tank device 1 may be reduced. In contrast, as in the present embodiment, by providing the coarse filter 4 at the front end of the return filter 3 and sandwiching the return filter 3 and the coarse filter 4 between two opposite side surfaces 2a and 2d of the tank 2 (so-called double support) structure, the strength of the tank device 1 can be improved.

[0106] Furthermore, by mounting the side surface of the return filter 3 to the side surface 2c via the tubular member 33, it is possible to prevent the return filter 3 and the coarse filter 4 from vibrating in the vertical direction as the tank device 1 vibrates, and the strength of the tank device 1 can be further improved.

[0107] In addition, in the present embodiment, the return filter 3 and the coarse filter 4 are provided near the bottom surface 2e, but the return filter 3 and the coarse filter 4 may also be provided at a position far from the bottom surface 2e. However, considering the safety of replacement operations, it is preferable to provide the return filter 3 and the coarse filter 4 near the bottom surface 2e.

[0108] In addition, in the present embodiment, the return filter 3 and the coarse filter 4 are integrated and provided inside the tank 2, but it is not necessary to integrate the return filter 3 and the coarse filter 4. For example, the return filter 3 may be provided horizontally inside the tank 2 only.

[0109] However, in the case where the coarse filter 4 is not provided at the front end of the return filter 3, in order to prevent the front end of the return filter 3 from moving in the vertical direction as the tank device 1 vibrates, it is preferable to mount the side surface of the return filter 3 to the side surface 2c via the tubular member 33 as in the present embodiment. However, from the perspective of strength, it is further preferable to provide the coarse filter 4 at the front end of the return filter 3 and sandwich the return filter 3 and the coarse filter 4 between two opposite side surfaces 2a and 2d of the tank 2.

[0110] In addition, in the present embodiment, a back pressure valve 38 is provided between the outflow pipe 34 and the coarse filter 4, but the back pressure valve 38 is not necessary. In the case where the back pressure valve 38 is not provided, it is only necessary to provide a hole on the side surface of the outflow pipe 34 and set the front end of the outflow pipe 34 to the coarse filter 4.

[0111] In addition, in the present embodiment, the back surface 41d of the insertion portion 41a has a concave shape of a substantially frustum of a cone, and the front surface 45b of the insertion portion 45a has a convex shape of a substantially frustum of a cone. However, the back surface 41d may have a convex shape of a substantially frustum of a cone, and the front surface 45b may have a concave shape of a substantially frustum of a cone. In addition, the back surface 41d and the front surface 45b need to have complementary shapes, but these shapes are not limited to the convex shape and the concave shape of a substantially frustum of a cone.

[0112] In addition, in the present embodiment, the diameters of the insertion portion 41a and the holes 24e and 24f are substantially the same as the diameters of the insertion portion 45a and the holes 35d and 35e. However, these diameters may not be substantially the same, as long as the diameters of the insertion portion 45a and the holes 35d and 35e are equal to or greater than the diameters of the insertion portion 41a and the holes 24e and 24f.

[0113] As described above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and also includes design changes and the like within the scope not departing from the gist of the present invention. For example, the above-described embodiments are detailed descriptions for easily understanding the present invention, and are not necessarily limited to having all the structures described. In addition, a part of the structure of an embodiment may be replaced with the structure of another embodiment, and other structures may be added to, deleted from, or replaced with the structure of the embodiment.

[0114] In addition, in the present invention, "substantially" means a concept that includes not only cases that are strictly the same, but also errors and deformations to the extent that equality is not lost. For example, "substantially cylindrical shape" is not limited to the case of a strictly cylindrical shape. In addition, for example, in the case of only being expressed as substantially in the center or the like, it includes not only the case of being strictly in the center or the like, but also the case of being substantially in the center or the like.

Claims

1. A box device, comprising: A box with a cavity inside; A return filter, which is horizontally arranged inside the box, and has a filter housing in a generally bottomed cylinder shape with one end being an opening, a filter head arranged inside the filter housing, and a filter element, the filter element having a generally cylindrical filter medium, a valve carrier member arranged on the end face of the filter medium, and a valve arranged on the valve carrier member; A cover body, which is arranged on the return filter in a manner of covering the opening; And A coarse filter, which is horizontally arranged inside the box and is arranged on the return filter, Characterized in that: The box has two generally parallel side faces, namely a first box side face and a second box side face, and an insertion hole is formed on the first box side face, The filter housing is arranged on the first box side face and is inserted into the inside of the box through the insertion hole, An outflow part for allowing the liquid that has passed through the filter medium to flow out into the box is arranged on the bottom surface of the filter housing, One end of the coarse filter is arranged at the outflow part, and the other end is arranged at the second box side face, The valve carrier member has a generally plate-shaped plate part, and the plate part is provided with a generally cylindrical first hole for allowing oil to flow into the filter medium and a second hole for allowing the oil filtered by the filter medium, that is, the filtered oil, to flow out, The valve has: A first valve, which has a first cover member and a first compression spring, the first cover member having a first insertion part that is inserted into the inside of the first hole to block the first hole, and the first compression spring arranging the first cover member at a position where the first insertion part blocks the first hole; and A second valve, which has a second cover member and a second compression spring, the second cover member having a second insertion part that is inserted into the inside of the second hole to block the second hole, and the second compression spring arranging the second cover member at a position where the second insertion part blocks the second hole, The filter head is provided with: A plate, which is formed with a third hole and a fourth hole; A third cover member, which has a third insertion part that can be inserted into the inside of the third hole; A fourth cover member, which has a fourth insertion part that can be inserted into the inside of the fourth hole; and A third compression spring, which applies a force in the direction towards the opening to the plate to arrange the plate at a position where the third cover member blocks the third hole and the fourth cover member blocks the fourth hole, When the filter element is inserted into the inside of the filter housing from the opening, the first surface of the first cover member abuts against the third surface of the third cover member, the second surface of the second cover member abuts against the fourth surface of the fourth cover member, and the plate abuts against the valve carrier member, When the filter element is pressed into the inside of the filter housing, the valve carrier member presses the plate against the acting force of the third compression spring, the third cover member presses the first cover member against the acting force of the first compression spring, and the fourth cover member presses the second cover member against the acting force of the second compression spring, When the filter element is inserted into the end of the filter housing, the first hole communicates with the third hole, and the second hole communicates with the fourth hole, so that the internal space of the filter element communicates with the internal space of the filter head.

2. The tank device according to claim 1, wherein: The return filter has a tubular member that communicates the outside of the tank with the inside of the filter housing, The tank has a third side of the tank that is adjacent to the first side of the tank and the second side of the tank, Holes for inserting the tubular member are respectively provided on the third side of the tank and the filter housing.

3. The tank device according to claim 1 or 2, wherein: The return filter and the coarse filter are provided near the bottom surface of the tank.

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