JPH0622577U - Suction filter - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a suction filter that is provided with a suction filter below the oil surface of an oil tank to remove a factor of sucking air and prevent oil from flowing out when a filter element is replaced. [Structure] A body which is attached to the opening on the lower side wall of the oil surface of the oil tank in a liquid-tight manner, and a body which is inserted from the side opposite to the oil tank to be closed and has a large number of communication holes in the body and opens toward the oil tank. A tubular support member, a filter element supported on the outer periphery of the support member, and a support member when the support member is attached to the body. When the support member is pressed by the end surface of the support member to open the valve and pull out the support member from the body. An on-off valve provided at an opening on the oil tank side of the body so as to close the valve by a spring force apart from the end face.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a suction filter of a hydraulic pump arranged in an oil tank for cleaning oil in a hydraulic device.

[0002]

[Prior art]

 Conventionally, in a general hydraulic system, in consideration of the ease of maintenance and replacement of the suction filter, a conduit is set up from inside the oil tank, and the suction filter is installed above and outside through a joint. The suction filter is located above. In addition, a suction filter provided inside the oil tank so that the filter element is below the oil level also has a conduit installed above and outside the oil tank. Furthermore, in a hydraulic system that uses water-glycol type hydraulic oil, cavitation easily occurs when air is sucked in, so it is necessary to install the suction filter below the oil level, as shown in Fig. 3. As described above, the suction filter 43 is provided through the opening / closing valve 42 connected to the oil tank 41 side wall below the oil level so that the internally installed filter element 44 is below the oil level of the oil tank 41. Before replacement, the suction filter 43 is closed by the on-off valve 42. At that time, in order to prevent the oil from leaking out due to an erroneous operation of the hydraulic pump 45, it is necessary to interlock the open / close limit of the open / close valve 42 and the power supply of the electric motor 46 of the hydraulic pump 45, and when the open / close valve 42 is closed. Detects the closing limit of the open / close handle 47 with the limit switch 48 and shuts off the power to prevent the motor 46 from operating. When the open / close valve 42 is fully open, the limit switch 49 opens the open limit of the open / close handle 47. It is interlocked to detect and connect the power supply circuit.

[0003]

[Problems to be solved by the device]

 As described above, when the suction filter is installed above and outside the oil tank, and when the filter element is below the oil level and a conduit is set up above and outside the oil tank to connect to the suction port of the hydraulic pump. Has air sucked from its joint, and cavitation is likely to occur in a hydraulic system that uses water-glycol hydraulic fluid.In particular, in the case of a piston pump, the suction pressure (negative pressure) increases and the pump There is a problem of deteriorating the suction characteristic. In order to solve this problem, as shown in FIG. 3, the suction filter 43 is connected to the on-off valve 42 arranged below the oil surface of the oil tank 41 so that the oil is below the oil surface of the oil tank 41. Although it is installed, in this case, in order to prevent the oil from leaking due to an erroneous operation, it is necessary to interlock the open / close limit of the open / close valve 42 and the power supply of the electric motor 45 of the hydraulic pump 44, and the number of joints increases. There is an air intake factor due to air leakage from the packing part of the on-off valve 42 itself.

An object of the present invention is to provide a suction filter provided below the oil surface of an oil tank to remove a factor of sucking air and prevent oil from flowing out when a filter element is replaced. To do.

[0005]

[Means for Solving the Problems]

 The present invention, which has been made to achieve the above-mentioned object, has a hollow body liquid-tightly attached to an opening formed below the oil surface on a side wall of an oil tank, and an outlet port provided on the outer periphery of the body. And a cylindrical support member having one end opening to the oil tank side and the other end closing the anti-oil tank side of the body and having a large number of communication holes in the central body portion, which is inserted into the body from the anti-oil tank side. And a filter element supported on the outer periphery of the support member, and when the support member is attached to the body, the end face of the support member on the oil tank side is pressed to open the valve and pull out the support member from the body. And an opening / closing valve provided at an oil tank side opening of the body so as to close the valve by a spring force away from the end surface of the supporting member.

[0006]

[Action]

 A hollow body is liquid-tightly attached to the opening formed below the oil surface on the side wall of the oil tank, and a cylindrical support member supporting a filter element on the outer periphery and having a large number of communication holes is inserted into the body. The outlet port provided on the outer periphery of the body is connected to the hydraulic pump, and the oil in the oil tank passes through the filter element to be cleaned and sucked into the hydraulic pump. The filter element is located below the oil surface of the oil tank, and the joint area is smaller than in the conventional case, so that the air suction factor is eliminated. When replacing the filter element, the on-off valve provided at the opening on the oil tank side of the body pushes the valve that was opened by the end surface of the inserted support member on the oil tank side and pulls out the support member from the body. The spring force closes the valve away from the end face of the support member to prevent oil spillage.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a hollow body, which is liquid-tightly attached to an opening 12 formed in a side wall 11 of the oil tank at a position below the oil level via a packing 13. Reference numeral 14 denotes a cylindrical support member, which has a large number of communication holes 16 in the central body portion, supports the filter element 15 on the outer periphery, and can be put in and taken out from the body 10 with the filter element 15 mounted. It is inserted into the body 10 and the opening 17 on the side opposite to the oil tank is closed by a flange 18 so as to be liquid-tightly attached to the body 10.

In the filter element 15, the packing 19 is sandwiched between one end surface of the filter element 15 and the inner partition wall of the body 10, and the leaf spring 20 is interposed between the other end surface and the flange 18 rear stepped portion. By pressing the packing 19 and mounting the O-ring 21 on the outer periphery of the support member 14 in the vicinity of the stepped portion, the inside of the body 10 and the supporting member 14 are made liquid-tight. Reference numeral 22 denotes a handle, which is provided integrally with the supporting member 14 at the portion of the flange 18 so that the supporting member 14 can be easily put in and taken out of the body 10.

An opening / closing valve 23 is fixed to a valve rod 25 that advances and retracts the disc 24. The valve rod 25 penetrates a boss 26 and is slidably supported. The boss 26 is integrally formed on the body 10 via a plurality of ribs 27, and a notch 28 is formed in the support member 14 so that the portion abutting the rib 27 is released. FIG. 1 illustrates a state in which the support member 14 is attached to the body 10. The tip 29 of the support member 14 on the oil tank side is in contact with the side surface of the disc 24 to open the on-off valve 23. . An outlet port 30 is provided downward on the outer periphery of the body 10 and is connected to a hydraulic pump suction port (not shown) via a flexible joint or the like.

FIG. 2 shows that the opening / closing valve 23 is pulled out from the body 10 when the support member 14 is pulled out from the body 10 by using the extraction bolt 32 that is screwed into the flange 18 and abuts against the end surface of the body 10 on the side opposite to the oil tank. 2 shows a state in which the hole 31 at the tip of the oil tank on the oil tank side is closed, and before the step portion 34 of the supporting member 14 on which the O-ring 33 is mounted comes out from the opening 17 on the anti-oil tank side of the body 10, Through the O-ring 35 fitted to the inclined outer peripheral surface, the inner peripheral surface of the hole 31 at the tip of the body 10 is abutted and liquid-tightly closed. In this case, it is not limited to the O-ring 35 as shown in the drawing, and other things such as packing may be used. Reference numeral 36 denotes a spring, which is interposed between the step portion at the other end of the valve rod 25 and the boss 26 to draw the disk 24 toward the boss 26 to apply a pressing force in the direction of closing the opening / closing valve 23. When the head 14 is pulled out from the body 10, the opening / closing valve 23 is closed by a spring force as the tip 29 of the support member 14 contacting the side surface of the disk 24 is separated.

In the state shown in FIG. 2, a drain valve (not shown) is opened to discharge the oil in the body 10 and to prevent the oil from flowing out from the opening 17 on the side opposite the oil tank of the body 10, and then the handle 22 Holding the filter element 15 and pulling out the support member 14 to the outside to remove the filter element 15 from the support member 14 for cleaning or replacement, and again with the filter element 15 attached to the support member 14 again. 1 is inserted into the body 10 and attached as shown in FIG. 1 to complete the cleaning or replacement work of the filter element 15.

[0012]

[Effect of device]

 By installing a suction filter on the lower wall of the oil surface of the oil tank, it is possible to improve the suction characteristics of the pump by removing the suction of air and reducing the suction pressure (negative pressure) in the case of a piston pump. Since it is possible, water-glycol type hydraulic oil has a remarkable effect. Also, when replacing the filter element, the on-off valve opens and closes in conjunction with the insertion and removal of the support member of the filter element, which prevents oil from leaking out, and at the same time as the conventional power supply for the hydraulic pump motor. No interlock required. Further, as a secondary effect, the floor space for installing the hydraulic pump can be made smaller than that of the conventional one, and the cost of the hydraulic system can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a state in which a support member for a filter element is attached to a body in an embodiment of a suction filter according to the present invention.

FIG. 2 is a sectional view illustrating a state in which a support member of a filter element is pulled out from a body in an embodiment of a suction filter of the present invention.

FIG. 2 is a schematic side view illustrating a usage state of a conventional suction filter.

[Explanation of symbols]

 10 body 14 support member 15 filter element 23 on-off valve 24 disc 25 valve rod 30 outlet port 36 spring

[Procedure amendment]

[Submission date] July 2, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a state in which a support member for a filter element is attached to a body in an embodiment of a suction filter according to the present invention.

FIG. 2 is a sectional view illustrating a state in which a support member of a filter element is pulled out from a body in an embodiment of a suction filter of the present invention.

FIG. 3 is a schematic side view illustrating a usage state of a conventional suction filter.

[Explanation of reference numerals] 10 body 14 support member 15 filter element 23 opening / closing valve 24 disc 25 valve rod 30 outlet port 36 spring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B01D 29/60 35/02

Claims (1)

[Scope of utility model registration request] 1. A hollow body liquid-tightly attached to an opening formed in a side wall of an oil tank below the oil surface, an outlet port provided on the outer circumference of the body, and the body from the side opposite to the oil tank. A cylindrical supporting member having one end opened to the oil tank side and the other end closing the anti-oil tank side of the body and having a large number of communication holes in the central body portion is supported on the outer periphery of the supporting member. When the support member is attached to the body, the filter element is pressed by the end surface of the support member on the oil tank side to open the valve, and when the support member is pulled out from the body, the spring force separates from the end surface of the support member. And a shut-off valve provided in the opening of the body on the oil tank side, the suction filter being configured to close the valve.