JPS63209710A - Oil filter - Google Patents

Abstract

PURPOSE:To keep the filtrating function for foreign matters for a long period and to reduce the exchanging frequency of filter by changing the density of filter paper of an element in the direction of hydraulic oil path by utilizing the pressure of the hydraulic oil. CONSTITUTION:The element 5, which is provided with an inner pipe 6 in its center, an outer paper pipe 7 in the its outer periphery, and a rolled filter paper 8 between them, is received in a vessel 1. And, a spacer 35 having a reinforcing function is integrally rolled around the lower outer peripheral surface of the paper pipe 7 to form a step part, and a thin film 38 consisting of an outer piece 39 and an inner piece 40 is integrally stuck to the lower part of the outer paper pipe 7 like a collar. Consequently, the lower part of the filter paper 8 is set to give higher density by the action of hydranlic oil pressure when the hydraulic oil is supplied into the vessel 1. As a result, the foreign matters of large diameter are filtrated at the upper part of the filter paper 8, and the matters of small diameter are caught at the lower part; so that the filtration is efficiently carried out regardless of the size of foreign matter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oil filter that is installed in a hydraulic circuit to clean oil.

[Conventional technology]

Injection molding machines, large machine tools, and the like are usually equipped with a hydraulic circuit for a hydraulic drive device such as a cylinder that moves a table, and a hydraulic circuit for lubricating a rotary drive unit.

The hydraulic fluid used in such hydraulic circuits becomes contaminated by minute foreign matter from the outside while circulating through the circuit.

For this reason, an oil filter is provided in the circuit to filter and clean the hydraulic oil in order to maintain lubrication ability and preserve equipment.

As shown in FIG. 6, oil filters that have been commonly used in the past have a structure in which an element C, which is a roll of filter paper B, is housed in a pressure-resistant container A.

A port for introducing hydraulic oil and a port (not shown) for collecting and discharging the hydraulic oil after filtering are provided at the bottom of the container, and the hydraulic oil circulating in the hydraulic circuit of the operating machine is continuously filtered. You can go there.

[Problem that the invention seeks to solve]

By the way, due to the filtration of the hydraulic oil, foreign substances contained in the hydraulic oil adhere to the element C, and eventually the filtering function of the filter paper B is lost. Therefore, it is necessary to replace element C periodically.

In the case of foreign matter adhering to the filter paper, the hydraulic oil is applied to the filter paper B, which is stacked in layers from the top to the bottom of C.
Since it flows while penetrating between the elements, the amount of adhesion increases quantitatively on the upper side of element C. In this case, since large foreign particles are easier to filter, foreign particles with a diameter of 3μ, for example, are collected on the upper side of element C, and 0.
．． Foreign matter with a diameter of about 5 μm passes through the upper side of the Niremen (C). Therefore, the diameter of the foreign matter to be collected is distributed differently in the vertical direction of the element C, and the filtering function cannot be performed satisfactorily unless foreign matter with a small diameter is collected, especially on the lower side.

On the other hand, since the filter paper B of the element C is wound tightly with a uniform winding force, the density of the filter paper B is also constant in the vertical direction through which the hydraulic oil passes. For this reason, even if foreign matter with a large diameter can be filtered on the upper side, if the density is not sufficient on the lower side, it will not be possible to collect foreign matter with a small diameter. Such a phenomenon is remarkable when the container A has a relatively deep shape with a long hydraulic oil bath.

As described above, in the element C formed by winding the filter paper B into a roll at a constant density, the upper end of the element C is rapidly accumulated with foreign matter, so that the interval between filter replacements is shortened. In addition, even if the filtration function is maintained, the collection of small-sized foreign matter may not be sufficient, and the frequency of filter replacement is also increased in order to maintain the cleanliness of the hydraulic fluid. be.

Therefore, the present invention utilizes the pressure of the hydraulic oil to change the density of the filter paper of the element in the path direction of the hydraulic oil, thereby maintaining the foreign matter filtering function for a long period of time and reducing the frequency of filter replacement. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention has a filter paper wound in a roll between an inner paper tube and an outer paper tube, which is housed in a container with its axis vertically oriented, and is actuated from the inner paper tube. In an oil filter that supplies oil upward and then discharges the inside of the filter paper downward, a gap is provided between the outer periphery of the outer paper tube and the inner wall of the container, and an inner circumferential surface of the lower end of the outer paper tube is provided. and the outer peripheral surface is covered with a thin film in a layered manner, and a plurality of holes are opened in the outer paper tube in the area covered with the film, and the pressure of the hydraulic oil flowing from the inner paper tube is applied to the outer paper tube and the outer paper tube. It is characterized in that it can be transmitted to the outer peripheral surface of the film located on the inner periphery of the outer paper tube through the gap between the inner wall of the container and the hole in the outer paper tube.

〔Example〕

Hereinafter, features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 is a partially cutaway front view of an oil filter showing an embodiment of the present invention.

A frame 2 for connecting and fixing the container 1 to a machine is attached to the lower part of the pressure-resistant container 1, and a lid 3 is detachably attached to the upper end of the container 1, and a hydraulic oil supply and drain is installed at the lower end. Port 4 is integrated. Inside the container 1, an element 5 made of paper wound into a roll is housed. This element 5 has an inner paper tube 6 at the center and an outer paper tube 7 on the outer periphery, and a filter paper 8 is wound between these, and the hydraulic oil flows down within this filter paper 8 from the upper end to the lower end. .

As shown in FIG. 1, the port 4 is provided with a hydraulic oil import port 9 and an out port 0, to which are connected a hydraulic oil supply pipe 11 and a recovery pipe 12, respectively. As shown in the sectional view of FIG. 2, the upper end of the port 4 is integrally formed with a protrusion 13 that protrudes upward at approximately the center of the container 1, and the protrusion 13 is provided with a female threaded hole 14. It is being A supply channel 15 from the import 9 is formed to communicate with the female threaded hole 14, and the female threaded hole 14 is provided with a protrusion 13.
A short-circuit flow path 16 is provided that radially penetrates through. Further, the outport 10 communicates with the inside of the container 1 through a recovery channel 17 whose end is open at the bottom of the container 1 .

A flange 18 is provided on the circumferential surface of the protrusion 1113 that forms the female threaded hole 14 and the short circuit passage 16, and the punching metal 19 whose center is supported by the flange 18 forms the short circuit passage 1.
It is placed above 6. Further, an annular projection 20 is formed on the inner wall of the container 1 to support the outer peripheral edge of the punched metal 19, and an edge 21 is provided on the upper surface of the annular projection 20 to receive the element 5 in a line contact state.

The lid 3 has an opening 22 in the center, as shown in the cross-sectional view of FIG.
, and an annular inner circumferential rib 23 and an annular outer circumferential rib 24 which respectively press down the inner paper tube 6 and outer paper tube 7 of the element 5 are protrudingly provided on the lower surface. The inner circumferential rib 23 has a stepped portion 25 formed at its lower end, and holds the stepped portion 25 inserted into the inner paper tube 6. In addition, these inner circumferential ribs 23 and outer circumferential ribs 24 are provided with notches 23a and 24a at predetermined pitch intervals.
is formed, and the hydraulic oil from inside the inner paper tube 6 is passed through the filter paper 8.
It is designed so that it can be guided not only to the upper end side but also to the gap between the outer paper tube 7 and the inner wall of the container 1. Furthermore, a projection 27 is provided in the annular groove 26 between the outer peripheral tube 24 and the outer peripheral surface of the lid 3 to protrude downward over the entire circumference. The sealing pressure to the packing 28 is kept high.

Furthermore, the female screw hole 1 of the protrusion 13 is inserted through the opening 22 of the lid 3.
The lid 3 is integrated with the container 1 by a fastening bolt 29 screwed into the lid 3 . This fastening bolt 29 has a bar 30 at its upper end.
The lower part of the upper end spatula 31 is sealed to the lid 3 around the opening 22 via a gasket 32 and a washer 33.

As shown in FIG. 2, on the lower end side of this fastening bolt 29, a communication passage 34 for hydraulic oil is formed in the axial direction from the lower end. The length of this communication channel 34 is such that the upper end is above the protrusion 13 when it is screwed almost completely into the female threaded hole 14.

FIG. 4 is an exploded perspective view of the element 5, which has a structure in which a roll of filter paper 8 is integrated into the annular space between the inner paper tube 6 and the outer paper tube 7 as described above.

A spacer 35 that also serves as reinforcement is provided at the lower end of the outer peripheral surface of the outer paper tube 7.
are integrally wound to form a stepped portion on the circumferential surface. Further, a plurality of holes 36 are opened at regular intervals in the circumferential direction on the spacer 35, and a pair of hooks 37 for taking out the container 1 from the container 1 are attached to the upper end. Furthermore, a thin film 3 made of polypropylene or the like is placed at the bottom of the outer paper tube 7.
8 is integrated into ambush. This film 38 has a cylindrical shape with its lower end bent outward, and as shown in FIG. The inner piece 40 extends to a higher position than the outer piece 39. In addition, the inner paper tube 6. including the film 38. After the outer paper tube 7 and the filter paper 8 are integrated, a mat 41 made of a material through which hydraulic oil can penetrate is attached to the lower surface.

In the above configuration, after the element 5 is housed in the container 1, the lid 3 can be firmly fixed to the container 1 by inserting the fastening bolt 29 through the opening 22 of the lid 3 and screwing it into the female screw hole 14. At this time, the inner paper tube 6 and outer paper tube 7 of the element 5 are pressed down by the inner circumferential rib 23 and outer circumferential rib 24 on the lower surface of the lid 3, respectively, and the element 5 is stabilized even in the presence of high-pressure hydraulic oil. It is possible to support. In addition, the seal 28 that seals the upper end of the container l and the lower surface of the lid 3 is
It is locally pressed by a protrusion 27 formed in the annular groove 26 of the lid 3. Therefore, the sealing pressure of the packing 28 can be increased, and the flowing hydraulic oil will not leak out from the sealed portion between the container 1 and the lid 3.

Next, when the hydraulic oil to be filtered is sent from the supply pipe 11,
The hydraulic oil flows from the supply channel 15 to the communication channel 3 in the direction of the arrow in the figure.
4 and is discharged into the space within the inner paper tube 6 of the element 5. After the hydraulic oil rises inside the inner paper tube 6, it enters the inside from the upper end of the filter paper 8, passes through the punching metal 19 while being filtered, and is finally discharged from the recovery channel 17 to the recovery tube 12. circulates through the machine's hydraulic circuit.

Here, when the supply of hydraulic oil is started, the hydraulic oil that has reached the upper end of the container 1 not only flows into the filter paper 8 but also flows into the lid 3.
From the plurality of notches 24a provided in the outer circumferential tube 24 of
The liquid flows to the outside of the container 1 and flows between the inner wall of the container 1 and the inner wall of the container 1. As shown in FIG. 5, the outer piece 39 of the film 38 is deformed outward by this inflowing hydraulic oil. That is, a gap is likely to be formed between the outer piece 39 and the circumferential wall of the outer paper tube 70 due to the spacer 35, and the hydraulic oil enters this gap so that the outer piece 39 is moved into the container 1 from the state shown by the dashed line in FIG.
Press toward the inner wall. Therefore, the outer piece 39 is
The container 1 is in close contact with the inner wall of the container 1, sealing the hydraulic oil flowing in from the upper side, and preventing the hydraulic oil from flowing down the inner wall of the container 1 to the recovery channel 17 side.

Simultaneously with the deformation of the outer piece 39 as described above, the hydraulic oil flows into the hole 36.
It flows into the outer paper tube 7 from there, passes along the outer surface of the inner piece 40 inside, and enters the filter paper 8 from the upper edge of the inner piece 40. At this time, since a large pressure is applied to the hydraulic oil, the inner piece 40 is loaded with external pressure due to the hydraulic oil and compresses the surrounding filter paper 8 toward its center. Therefore, the filter paper 8 is deformed in diameter as shown in FIG. 5 due to the compressive force from the outside, and as a result, the filter paper 8 in the area vertically surrounded by the inner piece 40 is deformed.
density is higher than that on the upper side.

As mentioned above, from the time when hydraulic oil is supplied into the container 1,
By using the pressure of the hydraulic oil, the density of the lower part of the filter paper 8 can be set high. For this reason, even when foreign matter with a small diameter passes through the filter paper 8 from top to bottom as described in the prior art section, these can be reliably filtered and collected.

In addition, the upper part of the filter paper 8 can filter foreign substances with a large diameter, and the lower part thereof can collect small-diameter foreign substances. Therefore, the filter can be efficiently filtered regardless of the size of the foreign matter, so if the entire element 5 is effectively utilized, the periodic replacement interval can be lengthened.

In addition, although what is shown in the drawing filters hydraulic oil using a single container 1, if the flow rate of hydraulic oil is large depending on the machine being used, multiple containers 1 may be used in parallel. Bye.

〔Effect of the invention〕

As explained above, in the oil filter of the present invention, the density of the filter paper is made larger than that on the upper side by compressing the lower side of the element using the pressure of the hydraulic oil. Therefore, even small foreign matter can be reliably filtered and collected, making it possible to maintain a high level of cleanliness of the hydraulic oil collected in the circuit. In addition, since the upper part of the filter paper collects large foreign substances and the lower part filters out small foreign substances,
It is possible to maintain the filtration function by effectively utilizing the entire filter paper.

As a result, the effective period of use can be extended and the frequency of filter replacement can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of an oil filter showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the port section, Fig. 3 is a longitudinal sectional view of the lid section, and Fig. 4 is an exploded element. Perspective view,
FIG. 5 is an enlarged longitudinal sectional view showing the deformation of the film at the lower end of the outer paper tube of the element, and FIG. 6 is a schematic diagram of a conventional oil filter structure. l: Container 3: Lid 4: Port 5: Element 6: Inner paper tube
7: Outer paper tube 8: Filter paper 11: Supply tube 12: Recovery tube 13: Protrusion 14: Female screw hole 15: Supply channel 16: Short-circuit channel 17: Recovery channel 23: Inner peripheral rib 24:
Outer circumferential block 29: Fastening bolt 34: Communication channel 35 varnish spacer 36: Hole 37: Hook 38: Film 39: Outer piece
40: Inner piece 41: Mat

Claims (1)

[Claims] 1. A filter paper wound in a roll between an inner paper tube and an outer paper tube is stored in a container with its axis in the vertical direction, and after supplying hydraulic oil upward from the inner paper tube, the inside of the filter paper is In an oil filter that discharges downward, a gap is provided between the outer periphery of the outer paper tube and the inner wall of the container, and the inner and outer circumferential surfaces of the lower end of the outer paper tube are covered with a thin film in the shape of a hakama. A plurality of holes are opened in the outer paper tube in the area covered with the film, and the pressure of the hydraulic oil flowing from the inner paper tube is applied to the gap between the outer paper tube and the inner wall of the container and the outer paper tube. An oil filter characterized in that the oil can be transmitted to the outer peripheral surface of a film located on the inner periphery of the outer paper tube through a hole in the tube.