JPH09299716A - Filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the load of clogging on filter paper to prolong filter replacement time by, between outside a filter of a filter device and a case, installing a spiral-shaped path whose section is gradually reduced. SOLUTION: In a cartridge 2, a spring 60, a spiral separation cylinder 3, a filter 4 and a gasket 61 are inserted into a case 55 which is closed by an end plate 62. The spiral separation cylinder 3 has a spiral-shaped path 3a whose section is gradually reduced between outside the filter 4 and the case 55, and has a conical plate 3b coaxial with the filter 4 and outside it and a plate 3c continuously fixed to a spiral outside the filter 4. When oil to be purified is introduced into a filter device 1, it enters the path 3a from an inlet path 51 of a filter head 53 through a path hole 63 of the cartridge 2, and it flows down in the spiral path between the adjacent stages of the plate 3c of the cylinder 3 by gravity while turning, and by centrifugal force generated then, heavy components such as sludge and light components are separated to the outside and the inside, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device, and more particularly to a filter device used in a vehicle diesel engine.

[0002]

2. Description of the Related Art Heretofore, a case of a cartridge type filter device in which a filter element and a case for accommodating the filter element, which are generally used in a diesel engine for a vehicle, are integrated and each case is replaced,
Also, a centrifugal spiral separator for separating water and sludge contained in heavy fuel oils for B and C fuels for ships is disclosed in JP-A-58-5420.
No. 2 publication, which is shown in FIGS.
It will be described based on 1. First, referring to FIG. 9, a cartridge type filter device 5 for a diesel engine for a vehicle.
0 will be described. The filter device 50 is composed of a cartridge 56 in which a filter head 53 that forms an oil inlet passage 51 and an oil outlet passage 52, a filter 54, and a case 55 that houses the filter 54 are integrated. A gasket 57 is interposed between the filter head 53 and the cartridge 56, and an oil passage hole 58 is provided.
It is screwed with a screw joint 59 having. In the cartridge 56, the spring 60, the filter 54, and the gasket 61 are inserted into the case 55, and the cartridge 56 is closed by the end plate 62. The end plate 62 is composed of an A end plate 63 and a B end plate 64, and is fixed by spot welding. A certain number of oil passage holes 63a are formed in the A end plate 63, and a screw 63b is formed in the center thereof. Further, the B end plate 64 is formed with an O-ring groove 64a, and the outer portion is fitted with the upper portion of the case 55 and is double-wound. The filter 54 is a filter paper 65 folded into a chrysanthemum shape.
, An upper end plate 66, a lower end plate 67, and an inner cylinder 68 having a passage hole 68a. The filter paper 65, the upper end plate 66, and the lower end plate 67 are fixed to each other with an adhesive.

Next, the operation will be described. The oil used in the diesel engine contains combustion products mixed from the combustion chamber, insoluble substances due to deterioration and decomposition of the oil, metal powder due to wear, and the like, and the filter device 50 filters these to obtain purified oil. It is working. The filter device 50 is a full-flow type filter arranged in series with the lubricating system of the engine. The full-flow type filter flows as follows. The primary side of the unpurified oil is pumped up by an oil pump from an oil pan of an engine (not shown), passes through an oil cooler, and passes through the filter device 50.
Is supplied to. The supplied non-purified oil on the primary side passes from the inlet passage 51 of the filter head 53 through the passage hole 63a of the cartridge 56, the inside of the case 55, and the filter 54.
Between the oil passage 55a and the oil passage 55a. The non-purified oil on the primary side passes through the filter paper 65 folded in a chrysanthemum shape from the passage 55a, and the purified oil on the secondary side passes through the passage hole 6 of the inner cylinder 68.
8a, through a passage hole 58 and an outlet passage 52, and is sent from a main gallery of an engine (not shown) to a sliding portion for rotation and reciprocation. Note that the safety valve when the filter is clogged is provided on the engine side. The filter device 50 is clogged and deteriorates with the running time of the engine, so it is periodically replaced. Replacement is in the form of a cartridge that can be easily replaced in each case.

Next, referring to FIGS. 10 and 11, a centrifugal spiral separator 70 for separating water and sludge contained in B and C fuel heavy oil for ships will be described. First, in FIG. 10, a centrifugal spiral separator 70 has a vertical spiral separation cylinder 72 fixed to the inside of a separator main body 71, and a spiral blade 73 of the spiral separation cylinder 72 is formed into a conical shape with an outer peripheral portion inclined downward. ,further,
An undiluted solution inlet 74 is opened at the top of the separator body 71, and a heavy liquid discharge port 75 is provided at the bottom of the separator body 71.
A light liquid discharge port 76 is provided at the center of the lower end of the spiral separating cylinder 72.

Next, the operation will be described. Undiluted liquid such as B and C fuel heavy oil is introduced from the undiluted liquid introduction port 74 by its hydraulic pressure, and flows down the spiral path between the spiral blades 73 of the spiral separation cylinder 72 while swirling by its hydraulic pressure and its own weight. The heavy components of the stock solution (for example, water, sludge) are separated to the outside of the spiral path, and the light components of the stock solution (for example, B and C heavy oil components) are separated to the inside due to the centrifugal force generated by the turning at this stage. Then, the spiral separation cylinder 72 is sufficiently separated to the lower part. Further, as described above, since the spiral blade 73 has a conical shape that inclines downward, the separating action due to the difference in specific gravity can be added to each spiral path, and the separating ability can be enhanced. After the separation, the heavy liquid is directly discharged from the heavy liquid discharge port 75 at the bottom of the separator body 71 and transferred to a drain or the like. On the other hand, the light liquid is a light liquid discharge port 76 provided at the bottom of the spiral separating cylinder 72.
Is discharged from the light liquid discharge port 78 through the light liquid passage 77. In this way, the undiluted solution can be centrifuged according to the difference in specific gravity, and can be used as a filter because sludge and the like are eliminated. As compared with a wire mesh filter, there is no clogging and the maintenance is simple. Is described.

[0006]

However, the filter device of the prior art as described above and Japanese Patent Laid-Open No. Sho 58-58.
The case of the centrifugal spiral separator disclosed in Japanese Patent Laid-Open No. 54202 has the following problems. In recent years, in addition to higher output of vehicle diesel engines, NO _X (nitrogen oxide) in exhaust gas,
There is a high need to reduce PM (particulate matter). Exhaust gas recirculation (EGR), combustion improvement, injection timing delay, etc.
Combustion products mixed in oil from the combustion chamber of the engine and insoluble substances due to deterioration and decomposition of oil tend to increase. A filter device for capturing these, i.e.
There is a need for a compact filter device with a long replacement life. If the combustion products of polluted oil and insoluble substances are deposited on the filter paper only with the conventional chrysanthemum-shaped filter paper, the tip part of the chrysanthemum-shaped mountain of the element will be crushed and the filter paper will be in a close contact state, reducing the filtration area. However, there is a drawback that the life of the filter is short. The centrifugal spiral separator is mainly intended to remove water sludge from B and C fuel heavy oil of a ship to clean it. In order to prevent engine wear and oil deterioration, an oil filter device for a high-output vehicle diesel engine requires a particle size of 15 μm or more for a full-flow filter and 5 μm or more for a bypass filter to prevent the oil from being deteriorated. . There is a problem that the centrifugal spiral separator alone does not satisfy the required use of the above-mentioned high-output vehicle diesel engine.

The present invention focuses on the above-mentioned conventional problems, and uses a conventional cartridge type structure in which a complicated work for replacing a filter and a small amount of dirt around the oil are used, and sludge contained in the oil, The purpose of the present invention is to provide a solution to the problem by preliminarily centrifuging abrasion powder, dust, etc., to reduce the load on the filter paper, extend the life of the filter replacement time, and provide a solution.

[0008]

In order to achieve the above object, in the first invention of the filter device of the present invention, the oil is provided between the outer diameter of the cylindrical filter and the case from the one end surface of the filter. In the filter device for supplying and filtering the filter by flowing it from the outer diameter side to the inner diameter side of the filter, a spiral passage is provided between the outer side of the filter and the case. . With such a configuration, it is possible to centrifuge sludge, abrasion powder, dust, etc. contained in the oil in advance, and reduce the load on the filter paper. Since the spiral passage has a gradually decreasing cross section between them, the centrifugal separation effect is greater toward the lower part of the case, and deposits such as sludge, abrasion powder, and dust can easily accumulate at the bottom of the case. As a result, it is possible to extend the life of the cylindrical filter (full flow) replacement time.

According to a second aspect of the invention, in the filter device of the first aspect, the spiral-shaped passage is concentrically arranged on the outside of the filter, and the conical plate is substantially perpendicular to the outside of the conical-shaped plate. , The plate is continuously fixed to the spiral, and the inner surface of the case. With such a configuration, it is possible to improve the same operation as the first aspect of the invention.

In the third invention, in the filter device of the first invention or the second invention, the magnet or the carbon adsorbent is provided on the inner surface of the outer case having the spiral shape. With this configuration,
This can be improved by the same action as that of the first aspect of the invention, and further, sludge, abrasion powder, dust, etc. can be better captured.

In the fourth invention, the bypass filters are arranged in series on the other end surface of the cylindrical filter. With such a configuration, it is possible to extend the service life of the replacement time of the combined filter device of the cylindrical filter and the bypass filter by the same operation as that of the first invention.

According to a fifth aspect of the invention, in the filter device of the first or fourth aspect of the invention, a bypass filter that allows the oil on the outer peripheral side that has been centrifugally separated to pass through the spiral passage and a oil that has passed on the inner peripheral side that has been centrifugally separated pass therethrough. It will consist of a cylindrical filter. With such a configuration, since the oil having a high dart concentration on the outer peripheral side, which has been centrifugally separated by the spiral passage, is supplied to and passed through the bypass filter side, the trapping efficiency can be increased and the cylindrical shape can be improved. On the filter side, the oil with a low dart concentration on the inner peripheral side, which has been centrifugally separated by a spiral passage, is supplied and passed through, so the load on the filter paper can be reduced, and as a result, the cylindrical filter (full flow) replacement time can be reduced. The life can be extended.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment will be described in detail below with reference to FIG. The first embodiment is a full-flow type filter device, which is an example of a filter device in which a spiral-shaped passage is provided on the outer periphery of a filtration element, centrifugally spirally separates, and then filtered by a filter. FIG. 1 shows an overall configuration diagram of an embodiment of a filter device 1 of the present invention. In addition,
Parts that are the same as in the prior art are given the same reference numerals and description thereof is omitted. In FIG. 1, the cartridge 2 has a case 55 into which a spring 60, a spiral separating cylinder 3, a filter 4, and a gasket 61 are inserted and is closed by an end plate 62. The spiral separating cylinder 3 has a spiral passage 3a between the outside of the filter 4 and the case 55, the cross-section of which gradually decreases, and a conical plate 3b concentrically arranged outside the filter 4 and a conical plate 3b. It is constituted by a plate 3c which is substantially perpendicular to the outside of the shaped plate 3b and which is fixed in a continuous spiral manner. Further, the upper part of the spiral separating cylinder 3 has an end plate 3d, which is fixed by a stop plate 5a of the upper end plate 5 of the filter 4, and the lower part thereof is a case 55.
It is open to the bottom of. The filter 4 includes a filter paper 6 folded in a chrysanthemum shape, an upper end plate 5, a lower end plate 7, and a passage hole 68a.
It is composed of an inner cylinder 68 having. The filter paper 6, the upper end plate 5, and the lower end plate 7 are fixed to each other with an adhesive.

Next, the operation will be described. Unpurified oil 1
The next side is pumped up by an oil pump from an oil pan of an engine (not shown), passes through an oil cooler, and is supplied to the filter device 1. The supplied non-purified oil on the primary side is supplied from the inlet passage 51 of the filter head 53 to the cartridge 2
Is introduced into the passage 3a of the spiral separating cylinder 3 through the passage hole 63a. The spiral passage between the plates 3c of the spiral separating cylinder 3 flows down while swirling due to its hydraulic pressure and its own weight, and the heavy component of the non-purified oil (for example, sludge) is generated by the centrifugal force generated by the swirling at this stage. , Abrasion powder, dust) to the outside of the spiral path, and light components of unpurified oil (eg oil)
Are separated to the inside, and are sufficiently separated to the lower part of the spiral separating cylinder 3. Further, since the cross section of the spiral path of the spiral separating cylinder 3 is gradually reduced from the upper part to the lower part, the flow velocity is increased and the centrifugal force causes a larger separation.
It is easy to collect at the bottom of No. 5. After the separation, the heavy liquid remains in the bottom of the case 55 as it is. On the other hand, the light liquid enters the passage 8 from the lower part of the spiral separating cylinder 3. The unpurified oil on the primary side passes through the filter paper 9 of the filter 4 folded in a chrysanthemum shape from the passage 8 and the purified oil on the secondary side passes through the passage hole 68 of the inner cylinder 68.
After passing through a, through the passage hole 58 and the outlet passage 52, it is sent from the main gallery of the engine (not shown) to the sliding portion for rotation and reciprocation. Note that the safety valve when the filter is clogged is provided on the engine side. By such an operation, the sludge, abrasion powder, dust, etc. contained in the oil can be centrifugally separated in advance to reduce the burden on the filter paper, and as a result, the life of the full flow filter replacement time can be extended. it can.

Next, a second embodiment will be described in detail with reference to FIGS. The second embodiment is an example of the filter device 10 of the first embodiment, in which a magnet or a carbon adsorbent is provided on the inner surface of an outer case having a spiral shape. 2 and 3 show the overall configuration of an embodiment of the filter device 10 of the present invention. The same parts as those in the prior art and the first embodiment are denoted by the same reference numerals, and description thereof is omitted. 2 and 3, the filter device 10
Is the magnet 11 on the inner surface of the spiral outer case 55.
Alternatively, a carbon adsorbent 12 (for example, cationic coating with static electricity added) is provided. The magnets 11 are fixed to the inner surface of a predetermined number of cases 55 with an adhesive. The carbon adsorbent 12 may be applied to the entire inner surface of the case 55. Next, the operation will be described. With the above-described structure, the spiral separation operation of the first embodiment can be improved, and further, sludge, abrasion powder, dust and the like can be better captured.

Next, a third embodiment will be described in detail with reference to FIG. The third embodiment is an example of a filter device 20 in which a cylindrical bypass filter is arranged in series on the other end surface of the cylindrical filter. FIG. 4 shows a filter device 2 of the present invention.
0 shows an overall configuration diagram of an embodiment of No. 0. The same parts as those of the conventional technique are designated by the same reference numerals and the description thereof will be omitted. 4, the filter device 20 is composed of a cartridge 24 in which a filter head 21 and a case 55 accommodating the cylindrical bypass filter 23 are integrally formed on the other end surface of the cylindrical filter 22. Filter head 21
And a cartridge 24 with a gasket 57 interposed therebetween and screwed together with a screw joint 25. The threaded joint 25 has a passage hole 25a through which full-flow oil flows and a passage hole 25b for oil from the bypass filter 23 formed at the center. The filter head 21 has an oil inlet passage 26, a full-flow oil outlet passage 27, oil outlet passages 28a and 28b from the bypass filter 23, and an orifice 28c. In the cartridge 24, a case 55 is inserted with a spring 60, a filter 22, an O-ring 31 a, a bypass filter 23, a spiral separating cylinder 3, and a gasket 29, and is closed by an end plate 62. The filter 22 is composed of a filter paper 30 folded into a chrysanthemum shape, an upper end plate 31 having an O-ring groove, a lower end plate 32, and an inner cylinder 33 having a passage hole 33a. Filter paper 30 and upper end plate 3
1 and the lower end plate 32 are fixed to each other with an adhesive. The bypass filter 23 is a filter paper 3 folded in a chrysanthemum shape.
4, upper end plate 35, lower end plate 36, and passage hole 3
It is composed of a middle cylinder 37 and an inner cylinder 38 having 7a. The filter paper 34, the upper end plate 35, and the lower end plate 36 are fixed to each other with an adhesive. Middle cylinder 37 and inner cylinder 38
Form an annular passage 39, and the upper end plate 35
The stopper 35a of the spiral separating cylinder 3 and the orifice 35 for adjusting the flow rate of the oil flowing through the bypass filter 23.
b is attached. The gasket 29 includes a passage groove 29a for the oil flowing through the bypass filter 33 and the passage hole 2
9b is provided.

Next, the operation will be described. The operation of the spiral separating cylinder 3 is the same as that of the first embodiment, and the explanation is omitted. The primary side of the unpurified oil is pumped up by an oil pump from an oil pan of an engine (not shown), passes through an oil cooler, and is supplied to the filter device 20. The supplied non-purified oil on the primary side passes from the inlet passage 26 of the filter head 21 through the passage hole 63a of the cartridge 24 to the spiral separation cylinder 3
Is introduced into the passage 3a. The non-purified oil is separated into a heavy component and a light component by the centrifugal force generated by the rotation of the spiral separating cylinder 3. After separation, the heavy liquid remains in Case 5
Collect at the bottom of 5. On the other hand, the light liquid enters the passage 8 from the lower part of the spiral separating cylinder 3. One of the passages 8 passes through the chrysanthemum-shaped folded filter paper 30 of the full-flow filter 22 arranged at the lower portion, the unpurified oil on the primary side is filtered, and the purified oil on the secondary side is passed through the passage of the inner cylinder 33. Passing through hole 33a, passage hole 25b,
After passing through the outlet passage 27, it is sent from a main gallery (not shown) of the engine to a sliding portion for rotation and reciprocation. Passage 8
The other one passes through the chrysanthemum-shaped filter paper 34 of the bypass filter 23 arranged on the upper side, the non-purified oil on the primary side is filtered, and the purified oil on the secondary side is filtered through the passage hole 3 of the middle cylinder 37.
Enter the annular passage 39 from 7a. From the annular passage 39 to the orifice 35b, passage groove 29a, passage hole 29b, passage hole 25
b, outlet passage 28a, orifice 28c, outlet passage 28
An oil pan of an engine (not shown) is sent through b. Rotation from the main gallery of the engine, not shown,
It is sent to the reciprocating movement. Note that the safety valve when the filter is clogged is provided on the engine side. By such an operation, the sludge, abrasion powder, dust, etc. contained in the oil can be centrifugally separated in advance to reduce the load on the filter paper. As a result, the life of the replacement time of the full flow filter and the bypass filter can be reduced. It can be extended.

Next, a fourth embodiment will be described in detail with reference to FIGS. 5, 6, 7 and 8. The fourth embodiment is an example of a filter device 40 including a bypass filter that passes oil on the outer peripheral side that has been centrifugally separated in a spiral passage and a cylindrical filter that passes oil that has been centrifugally separated on the inner peripheral side. FIG. 5 shows an overall configuration diagram of an embodiment of the filter device 40 of the present invention. The same parts as those of the conventional technique are designated by the same reference numerals and the description thereof will be omitted. In FIG. 5, the filter device 40 is composed of a filter head 41 and a cartridge 42. Filter head 41 and cartridge 4
A gasket 57 is interposed between the two and a screw joint 59. The filter head 41 has an oil inlet passage 41.
a, a full-flow oil outlet passage 41b is formed, and a passage pipe 4 for the outlet oil from the bypass filter is formed in the central portion.
3 is inserted. As shown in FIG. 6, the upper part of the passage pipe 43 is formed into a flare shape 43a and sealed at an end of a joint (not shown). An orifice 43b is formed below the passage pipe 43. Cartridge 42 is case 5
5, spring 60, bypass filter 45, filter 4
4, the spiral separating cylinder 3, and the gasket 61 are inserted and closed by the end plate 62. The filter 44 includes a filter paper 6 folded in a chrysanthemum shape, an upper end plate 5, a lower end plate 46, and a passage hole 68a.
It is composed of an inner cylinder 68 having a passage and a passage pipe 47.
The filter paper 6, the upper end plate 5, and the lower end plate 46 are fixed to each other with an adhesive. As shown in FIG. 7, the upper portion of the passage pipe 47 disposed in the center of the filter 44 is provided with the passage hole 4
It is composed of an end plate 47b having 7a and a gasket 47c. The end plate 47b and the inner cylinder 68 are spot-welded, and the gasket 47c and the end plate 47b are fixed by an adhesive. Further, the passage pipe 47 and the end plate 47b are welded. The bypass filter 45 is composed of a filter paper 45a folded in a chrysanthemum shape, an upper end plate 45c having a notch 45b, a lower end plate 45d, and an inner cylinder 45f having a passage hole 45e as shown in FIG. ing. The filter paper 45a, the upper end plate 45c, and the lower end plate 45d are fixed to each other with an adhesive. A gasket 48 is attached to the center of the upper end plate 45c.

Next, the operation will be described. The operation of the spiral separating cylinder 3 is the same as that of the first embodiment, and the explanation is omitted. The primary side of the unpurified oil is pumped by an oil pump from an oil pan of an engine (not shown), passes through an oil cooler, and is supplied to the filter device 40. The supplied unpurified oil on the primary side is the inlet passage 41a of the filter head 41.
Is introduced into the passage 3a of the spiral separating cylinder 3 through the passage hole 63a of the cartridge 42. The unpurified oil is separated into a heavy component on the outer peripheral side and a light component on the inner peripheral side by the centrifugal force generated by the turning of the spiral separating cylinder 3. The separated non-purified oil is divided into two directions at the lower part of the spiral separation cylinder 3. On one side, the non-purified oil of heavy component on the outer peripheral side flows to the bypass filter 45 side, and on the other side, the full-flow filter 4
Non-purified oil of a light component on the inner peripheral side flows to the 4 side. The heavy component non-purified oil that has flowed to the bypass filter 45 side passes through the filter paper 45a, the primary-side non-purified oil is filtered, and the secondary-side purified oil flows from the passage hole 45e of the inner cylinder 45f to the passage pipe 47. The flow rate is adjusted by the orifice 43b, and the oil is sent to an oil pan (not shown) of the engine via the passage pipe 47. The non-purified oil as a light component that has flowed to the full-flow filter 44 side passes through the filter paper 6 from the passage 8 and
The non-purified oil on the secondary side is filtered, and the purified oil on the secondary side is passed from the passage hole 68a of the inner cylinder 68 to the passage hole 47a and the passage hole 5
8, through the outlet passage 27, it is sent from the main gallery of the engine (not shown) to the sliding portion of the rotating and reciprocating motion. By such an operation, sludge, abrasion powder, dust, etc. contained in the unpurified oil are centrifugally separated in advance, and the bypass filter 45 side is provided with the oil having a high Dult concentration on the outer peripheral side centrifugally separated by the spiral passage. Since it is supplied and passed, the capture efficiency can be increased and the full flow filter 4 can be used.
On the 4 side, the oil having a low dart concentration on the inner peripheral side, which has been centrifugally separated by the spiral passage, is supplied and passed, so that the load on the filter paper can be reduced, and as a result, the life of the full flow filter 44 replacement time is reduced. It can be extended.

[0020]

As described above, according to the present invention,
Using a conventional cartridge type structure where the filter device does not require complicated work when replacing the filter and the surrounding dirt on the oil is small, the sludge separation cylinder centrifuges sludge, abrasion powder, dust, etc. contained in the oil in advance. Moreover, the load on the filter paper can be reduced by providing a magnet or a carbon adsorbent on the inner surface of the case. As a result, the filter replacement time is extended and the problem is solved.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of a first embodiment of a filter device according to the present invention.

FIG. 2 shows a cross sectional view of a second embodiment of the filter device of the invention.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 shows a cross-sectional view of a third embodiment of the filter device of the present invention.

FIG. 5 shows a cross-sectional view of a fourth embodiment of the filter device of the present invention.

FIG. 6 shows an enlarged detailed view of a P portion of FIG.

FIG. 7 shows an enlarged detailed view of a Q portion of FIG.

FIG. 8 is a sectional view taken along line BB in FIG.

FIG. 9 shows a cross-sectional view of a prior art filter device.

FIG. 10 shows a cross-sectional view of a prior art filter device.

11 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 1, 10, 20, 40 Filter device 3a Passage 3b, 3c Plate 11 Magnet 12 Carbon adsorbent 22, 44, 54 Filter 23, 45, Bypass filter 55 Case

Claims (5)

[Claims] Claim: What is claimed is: 1. A filter device for supplying oil between the outer diameter of a cylindrical filter and the case from one end surface of the cylindrical filter and flowing the oil from the outer diameter side to the inner diameter side of the filter for filtering. A filter device, characterized in that a spiral-shaped passage having a gradually decreasing cross section is provided between the outside and the case. 2. The filter device according to claim 1, wherein the spiral-shaped passage has a conical plate arranged concentrically outside the filter, and the spiral passage is substantially perpendicular to the outer side of the conical plate and spirally. A filter device comprising a plate that is continuously fixed and an inner surface of a case. 3. The filter device according to claim 1, wherein a magnet or a carbon adsorbent is provided on the inner surface of the case outside the spiral passage. 4. The filter device according to claim 1, wherein a bypass filter is arranged in series on the other end surface of the cylindrical filter. 5. A bypass filter that allows the oil on the outer peripheral side that has been centrifugally separated in a spiral passage to pass therethrough, and a cylindrical filter that allows the oil on the inner peripheral side that has been centrifugally separated to pass therethrough. Alternatively, the filter device according to claim 4.