Oil mist removal device

Abstract

To provide an oil mist removal device capable of easily removing oil mist.SOLUTION: An oil mist removal device comprises: a main body case which has a motor that rotates a suction fan that draws in air through an intake port and an exhaust port that is provided vertically above the rotation shaft of the motor; and a filter which extends from the exhaust port to the interior of the main body case, and has a circular cross-sectional shape perpendicular to the extending direction. With this configuration, the device can easily remove oil mist contained in the air discharged from the exhaust port. Furthermore, when the filter is, for example, cylindrical, the surface area of the filter increases, thereby extending the service life of the filter.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an oil mist removal device.

Background Art

[0002] Conventionally, in processing apparatuses such as those for cutting, grinding, and forging metals, a large amount of cutting oil has been used for cooling workpieces and tools to be processed and for washing and recovering cutting powder. During the use of this cutting oil, oil mist is generated when the cutting oil becomes atomized, evaporates, and condenses. Since oil mist is harmful to the human body, equipment, and the environment, etc., measures for removing oil mist are required from both aspects of maintaining a safe and comfortable workplace environment and protecting the natural environment around the site. As a measure for removing oil mist, it has become mainstream to connect an oil mist removal device to the processing apparatus via a duct to remove the oil mist. As a measure for removing this oil mist, for example, an oil mist removal device described in Patent Document 1 has been published.

[0003] In Patent Document 1, as shown in FIG. 3 of Patent Document 1, a main body 13 having a first collection region 101 and a second collection region 102, a suction fan 50 disposed in the first collection region 101 of the main body 13 for discharging the sucked air to the inner peripheral surface of the main body 13 to cause collision, a disk 70 that forms slits between a plurality of radially provided bar portions and knocks the air discharged from the suction fan 50 and attempting to pass through the slits with the bar portions to separate the oil mist in the air, at least one motor 40 for rotating the suction fan 50 and the disk 70, a first discharge mechanism portion disposed on the bottom surface of the main body 13 for discharging the oil mist separated by the suction fan 50, and a second discharge mechanism portion disposed on the bottom surface of the main body 13 for discharging the oil mist separated by the disk 70 are provided. An oil mist removal device is described.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] On the other hand, in the disclosed technology of Patent Document 1, as shown in FIG. 1 of Patent Document 1, a flat filter held at the exhaust port 14 is used to capture the oil mist. However, since this flat filter is arranged along the exhaust port 14, its surface area cannot be increased. For this reason, there has been a problem that the life of the filter is short and the maintenance frequency is high.

[0006] Further, in the disclosed technology of Patent Document 1, as shown in FIG. 3 of Patent Document 1, an exhaust guide plate 80 or the like is provided inside the main body 13 to capture the oil mist. For this reason, the oil mist removing device described in Patent Document 1 has a problem that the number of necessary parts increases and the cost increases. Also, even when cleaning the inside of the main body 13, since the exhaust guide plate 80 or the like is provided inside the main body 13, the internal structure becomes complicated, so there is a problem that the cleaning is time-consuming and the cost increases.

[0007] Therefore, the present invention has been devised in view of the above-described problems, and an object thereof is to provide an oil mist removing device capable of easily removing oil mist.

MEANS FOR SOLVING THE PROBLEMS

[0008] An oil mist removing device according to a first invention includes a main body case having a motor that rotates a suction fan for sucking air from an intake port and an exhaust port provided above a rotation shaft of the motor, and a filter that extends from the exhaust port to the inside of the main body case and has a substantially circular cross-sectional shape perpendicular to the extending direction.

[0009] The oil mist removal device according to the second invention is characterized in that, in the first invention, it further includes a return portion that is folded back from the exhaust port in the extending direction.

[0010] The oil mist removal device according to the third invention is characterized in that, in the second invention, the return portion is formed along the substantially circular shape of the filter.

[0011] The oil mist removal device according to the fourth invention is characterized in that, in the first invention, it further includes a filter fixture provided inside the filter and having an inner frame portion that extends in the extending direction along the inner peripheral surface of the filter.

[0012] The oil mist removal device according to the fifth invention is characterized in that, in the fourth invention, the filter fixture has one or more pressing portions each consisting of a linear bottom portion and the inner frame portion formed by folding back both ends of the bottom portion.

[0013] The oil mist removal device according to the sixth invention is characterized in that, in the first invention, it further includes a disk provided in the main body case and having slits, and a drain port that vertically penetrates the bottom surface below the disk in the main body case.

Advantages of the Invention

[0014] According to the first to sixth inventions, the oil mist removal device includes a filter that extends from the exhaust port to the inside of the main body case and has a substantially circular cross-sectional shape perpendicular to the extending direction. Thereby, it becomes possible to easily remove the oil mist contained in the air discharged from the exhaust port. Further, for example, when the filter is cylindrical, the surface area of the filter becomes large, so it becomes possible to extend the life of the filter. Also, since the filter becomes longer in the extending direction, the oil captured by the filter flows and diffuses in the extending direction, so it becomes possible to uniformly utilize the filter, and thus it becomes possible to extend the life of the filter. Further, for example, when the filter is cylindrical, the attachment and detachment of the filter become easy, so it becomes possible to easily replace the filter.

[0015] In particular, according to the second invention, the oil mist removal device includes a return portion that is folded back in the extending direction from the exhaust port. As a result, since the return portion serves as a return for the air flow in the main body case, it becomes possible to create a turbulent flow of the air in the main body case, preventing the oil mist from passing through the filter and flying out. Further, it becomes possible to disperse the oil mist throughout the filter without concentrating the oil mist on the upper part of the filter. For this reason, it becomes possible to reduce the load on the filter, and thus it becomes possible to make the filter last longer.

[0016] In particular, according to the third invention, the return portion is formed along the substantially circular shape of the filter. As a result, the air passing through the filter collides with the return portion, making it possible to more efficiently create a turbulent flow of the air. This makes it possible to disperse the oil mist throughout the filter without concentrating the oil mist on the upper part of the filter. For this reason, it becomes possible to reduce the load on the filter, and thus it becomes possible to make the filter last longer.

[0017] In particular, according to the fourth invention, the oil mist removal device includes a filter fixture provided inside the filter and having an inner frame portion that extends along the inner peripheral surface of the filter in the extending direction. This makes it possible to fix the shape of the filter along the inner peripheral surface of the filter.

[0018] In particular, according to the fifth invention, the filter fixture has one or more pressing portions each consisting of a linear bottom portion and an inner frame portion formed by folding back both ends of the bottom portion. This makes it possible to fix the shape of the filter along the inner peripheral surface while minimizing the portions that obstruct the air flow passing through the filter.

[0019] In particular, according to the sixth invention, the main body case has a drain port that penetrates vertically through the bottom surface below the disk. This makes it possible to efficiently discharge, for example, the oil mist collected by the disk and accumulated in the main body case.

Brief Description of the Drawings

[0020]

Figure 1

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Figure 12

Modes for Carrying Out the Invention

[0021] An example of an oil mist removal device 100 in the present embodiment of the present invention will be described with reference to the drawings.

[0022] The oil mist removal device 100 is a device that removes oil mist contained in the sucked air. As shown in FIG. 1, the oil mist removal device 100 includes a main body case 1 having an air intake port 12 for sucking air and an exhaust port 11 for exhausting air, a filter 2 extending from the exhaust port 11 to the inside of the main body case 1, and a filter fixture 3 provided inside the filter 2.

[0023] The main body case 1 is a device main body having a substantially cylindrical shape. Also, the main body case 1 is not limited to a cylindrical body with a circular cross-section, and may be, for example, a cylindrical body or a box body with a square cross-section or a polygonal cross-section. However, the main body case 1 is not limited to this, and any shape that can cause the air containing oil mist to collide with the inner peripheral surface and separate and collect the oil mist is acceptable.

[0024] FIG. 2 is a view showing a cross-section of the oil mist removal device 1 in the xz plane in FIG. 1. As shown in FIG. 2, in the main body case 1, a first mounting plate 41 and a second mounting plate 42 are sequentially provided along the x-axis direction on the inner peripheral surface 1c of the main body case 1. Also, a motor 40 is mounted on the inner surface of the second mounting plate 42, and a connecting fitting 44 is mounted on the rotating shaft 43 of the motor 40. Also, a suction fan 50 is mounted at the tip of the connecting fitting 44, and a disk 70 is mounted at the base of the connecting fitting 44. Also, a rectifying plate 60 is mounted on the outer surface of the first mounting plate 41.

[0025] The main body case 1 also has an air intake port 12 for taking in air by the suction fan 50 and an exhaust port 11 that opens at a height above the rotation axis L of the motor 40 in the vertical direction z and exhausts air. The main body case 1 has, for example, an air intake port 12 that opens on the front surface 1d and an exhaust port 11 that opens on the ceiling 1b. Further, the main body case 1 has a drain port 15 that penetrates the bottom surface 1a below the disk 70 of the main body case 1 in the vertical direction z and discharges oil. Also, the main body case 1 is provided with a circulation rib 16 for receiving an oil mist provided along the inner peripheral surface 1c on the x-direction side of the opening 15a of the drain port 15. Further, the main body case 1 may be provided with a net or punching metal (not shown) having an opening width dimension of about 1 mm to 10 mm so as to block the air intake port 12. Also, the x direction is the inward surface direction, and the direction opposite to the x direction is the outward surface direction.

[0026] The motor 40 is a device that rotates the disk 70 and the suction fan 50. The motor 40 may be, for example, one with an output of 0.2 kW, 0.4 kW, 0.75 kW, 1.5 kW, 2.2 kW, etc., but is not limited to this, and one with an arbitrary output may be used. Also, the motor 40 may be, for example, a three-phase induction motor, a permanent magnet motor, etc., but is not limited to this, and any one may be used. Further, the motor 40 may be, for example, one that can be rotated at a rotational speed of 2400 - 3600 rpm. Also, a plurality of motors 40 may be used. In such a case, the plurality of motors 40 may be rotated in the same direction, but are not limited to this, and may be rotated so that the suction fan 50 and the disk 70 rotate in different directions.

[0027] FIG. 3 is a diagram showing an example of the suction fan 50 in the present embodiment. The suction fan 50 is a fan for sucking air from the air intake port 12. As shown in FIG. 3, the suction fan 50 has a sandwich structure in which a plurality of curved rotating blades 53 are attached in a substantially radial direction at equal angles between a circular mounting disk 51 and a concentric suction disk 52 facing each other.

[0028] FIG. 4 is a diagram showing an example of the rectifying plate 60 in the present embodiment. As shown in FIG. 4, the rectifying plate 60 is composed of a circular rectifying substrate 61 and a plurality of rectifying vanes 65 evenly and radially attached to the rectifying substrate 61. As shown in FIG. 4, the rectifying substrate 61 is formed by connecting and integrating concentric disks 62 and 63 arranged concentrically via four cross members 64. The rectifying vane 65 is punched out from a thin metal plate so as to connect and integrate both ends of an upper side portion 66 and a lower side portion 67 that are curved concentrically with substantially strip-shaped connecting portions 68 and 69. Further, the rectifying vane 65 is formed in a substantially fan shape in the front view by bending the connecting portions 68 and 69 at a substantially right angle in the same direction. Note that the diameter of the outer peripheral circle drawn by connecting the outer peripheral edge portions of the rectifying vane 65 is larger than the outer diameter of the suction fan 50.

[0029] FIG. 5 is a diagram showing an example of the disk 70 in the present embodiment. FIG. 6 is a diagram showing an example of the enlarged disk 70 in the present embodiment. FIG. 7 is a diagram showing an example of the reinforcing plate 78 constituting the disk 70 in the present embodiment. As shown in FIGS. 5 to 7, the disk 70 has a shape in which a plurality of annular members 72 arranged around a disk 71 located at the center are connected and integrated by a plurality of connecting portions 73. Note that in FIGS. 5 and 7, for convenience of explanation, the slits are not shown. Further, the disk 70 is formed with slits 74 radially at a predetermined pitch by etching in a region Z that is a region located between two connecting portions 73, whereby cross members 75 are formed between the slits 74. Further, the disk 70 is reinforced by laminating and integrating a reinforcing plate 78 on the back surface by welding or the like, but it is not limited thereto, and the reinforcing plate 78 may not be provided. Further, the thickness dimension of the disk 70 is preferably from 0.2 mm to 2.0 mm. Further, since the slits 74 of the disk 70 are formed radially, when air containing oil mist passes through, the disk 70 discharges the air accelerated toward the inner peripheral surface of the main body case 1 by centrifugal force. Therefore, clogging is less likely to occur, and the period without requiring maintenance can be extended.

[0030] In addition, the outer shape, number, arrangement, etc. of the slit 74 and the crosspiece 75 can of course be appropriately selected as needed. That is, if the width dimension of the slit 74 is wide, it is less likely to become clogged and the period without the need for maintenance becomes longer, but since it becomes easier to ventilate, the oil mist collection performance decreases. On the other hand, if the width dimension of the crosspiece 75 is too narrow, the mechanical strength cannot be ensured. Conversely, if the width dimension of the crosspiece 75 becomes too wide, oil mist and fine dust are likely to adhere to the crosspiece 75, which causes clogging, so the period without the need for maintenance becomes shorter. Also, if the width dimension of the crosspiece 75 is too large, the total opening area of the entire disk 70 becomes small and the passing air velocity through each slit 74 increases, so the mist collection performance decreases. From these facts, according to the present embodiment, the width dimension of the slit 74 is preferably from 0.3 mm to 1.5 mm. This is because if it is less than 0.3 mm, it is difficult to process and the oil mist is likely to become clogged, shortening the period without the need for maintenance. Also, if it exceeds 1.5 mm, the collection efficiency decreases. Further, the length dimension of the slit 74 is preferably from 20 mm to 60 mm. This is because if it is less than 20 mm, the total opening area becomes small and the velocity of the air passing through the slit 74 becomes fast, so the oil mist easily slips through and the collection efficiency decreases. Also, if it exceeds 60 mm, the strength decreases. The width dimension of the crosspiece 75 is preferably from 0.5 mm to 2.5 mm. This is because if it is less than 0.5 mm, the strength decreases. Also, if it exceeds 2.5 mm, the total opening area becomes small and the velocity of the air passing through the slit 74 becomes fast, so the oil mist easily slips through and the collection efficiency decreases.

[0031] Next, the filter 2 will be described with reference to FIGS. 2 and 8. FIG. 8(a) is a plan view showing an example of the filter 2 in the present embodiment. FIG. 8(b) is a view showing an example of the bottom surface 20b of the filter 2 in the present embodiment. As shown in FIG. 2, the filter 2 is a component for removing oil mist contained in the exhaust gas attached to the exhaust port 11 of the main body case 1. The filter 2 extends from the exhaust port 11 to the inside of the main body case 1 and is a filter having a substantially circular cross-sectional shape perpendicular to the extending direction. In such a case, the extending direction may be, for example, the vertical direction z, but is not limited thereto, and may be any direction as long as the angle with the vertical direction z is less than 90°. Also, the substantially circular shape may be, for example, a circular shape or an elliptical shape. The filter 2 may be removable from the main body case 1, but is not limited thereto, and may be attached to the exhaust port 11 of the main body case 1.

[0032] As shown in FIG. 8, for example, the filter 2 includes a removal part 20 composed of a cylindrical side surface 20a and a circular bottom surface 20b at the vertical direction z end of the side surface 20a, and a resin part 21 at an opening 20c above the vertical direction z at the end of the removal part 20. The removal part 20 is not limited to a cylindrical shape, and may be, for example, a tapered shape whose diameter increases or decreases as it progresses in the vertical direction z. Also, the removal part 20 may be composed of, for example, a non-woven fabric, but is not limited thereto, and any material that can permeate air and capture oil mist contained in the air may be used. Also, the length of the removal part 20 in the extending direction may be any length.

[0033] The resin part 21 may be connected to the removal part 20, for example, by being sewn to the removal part 20, but is not limited thereto, and may be connected to the removal part 20 by any method. Thereby, compared with the case of connecting using an adhesive, for example, the adhesive force does not decrease due to oil, so it is possible to use it for a longer period of time.

[0034] Further, the resin part 21 may be provided at the exhaust port 11 of the main body case 1 instead of the filter 2. The resin part 21 is constituted by, for example, a resin component, but is not limited thereto and may be constituted by any component. The resin part 21 has, for example, an edge part 23 that spreads around the opening part 20c of the removing part 20, and a return part 24 that is folded back from the edge part 23 in the extending direction of the filter 2. The edge part 23 is, for example, a rim that extends substantially perpendicular to the extending direction and in a substantially concentric direction with respect to the opening part 20c of the removing part 20. The return part 24 preferably has a return surface 24a that is a surface perpendicular to the opening surface of the opening part 20c, but is not limited thereto and may be any surface that is folded back from the edge part 23 into the main body case 1. The return part 24 may have, for example, a substantially circular shape in which the cross section perpendicular to the extending direction becomes larger or smaller as it advances in the extending direction. The return part 24 is formed, for example, along the opening part 20c. The length of the return part 24 in the extending direction may be any length as long as it is shorter than the height h in the vertical direction z of the side surface 20a of the removing part 20. The return part 24 may be formed, for example, along the removing part 20 of the filter 2. It may be formed along the inner peripheral surface of the side surface 20a of the removing part 20, but is not limited thereto and may be formed along the outer peripheral surface of the side surface 20a of the removing part 20. Further, the return part 24 may be provided with slits of any shape (not shown). 1 If it is shorter than that, it may have any length. The return part 24 may be formed, for example, along the removing part 20 of the filter 2. It may be formed along the inner peripheral surface of the side surface 20a of the removing part 20, but is not limited thereto and may be formed along the outer peripheral surface of the side surface 20a of the removing part 20. Further, the return part 24 may be provided with slits of any shape (not shown).

[0035] Next, the filter fixture 3 will be described with reference to FIGS. 1 and 9. FIG. 9(a) is a plan view showing an example of the filter fixture 3 in the present embodiment. FIG. 9(b) is a view showing an example of the bottom edge portion 32b of the filter fixture 3 in the present embodiment. The filter fixture 3 is provided inside the filter 2 and fixes the shape of the filter 2. As shown in FIG. 9, the filter fixture 3 is composed of a fixed edge portion 31 with an opening 31a opened and one or more pressing portions 32 connected to the fixed edge portion 31. The fixed edge portion 31 is a rim that extends in a substantially concentric circular direction of the opening 31a. The pressing portion 32 has an inner frame portion 32a that extends in the extending direction along the inner peripheral surface of the filter 2. The pressing portion 32 may be composed of, for example, a linear bottom edge portion 32b and two inner frame portions 32a formed by folding both ends of the bottom edge portion 32b toward the fixed edge portion 31 side. Also, in such a case, it may be formed in a tapered shape in which the distance between the two inner frame portions 32a becomes smaller as it approaches the bottom edge portion 32b from the fixed edge portion 31. Thereby, while fixing the shape of the filter 2, it becomes possible to easily attach and detach the filter 2. Further, the filter fixture 3 may have two pressing portions 32 provided such that the two bottom edge portions 32b intersect perpendicularly in the vertical direction z of the center of the opening 31a.

[0036] Also, the height h of the inner frame portion 32a in the vertical direction z 2 is higher than the height h of the side surface 20a of the removal portion 20 in the vertical direction z 1 and the length t of the bottom edge portion 32b 2 is preferably shorter than the diameter t of the bottom surface 20b of the removal portion 20 1 but this is not the limit.

[0037] Next, a method for assembling the oil mist removal device 100 will be described with reference to FIG. 10. FIG. 10 is a diagram showing an example of the operation of attaching the filter 2 and the filter fixture 3 in the present embodiment. As shown in FIG. 10, in the oil mist removal device 100, the filter 2 is inserted into the exhaust port 11 of the main body case 1 along the vertical direction z. In such a case, by locking the edge portion 23 to the edge of the exhaust port 11, it is possible to prevent the filter 2 from falling inside the main body case 1. Next, the filter fixture 3 is inserted along the vertical direction z through the opening 20c of the filter 2. Thereby, the inner frame portion 32a of the filter fixture 3 fixes the shape of the side surface 20a of the removal portion 20, and the bottom portion 32b of the filter fixture 3 fixes the shape of the bottom surface 20b of the removal portion 20. Further, the main body case 1, the filter 2, and the filter fixture 3 may be fixed by the nut 4. Thereby, even when the oil mist removal operation is performed inside the main body case 1, the shape of the filter 2 can be fixed, so that the oil mist can be removed more efficiently. Further, since the filter 2 is housed inside the main body case 1, the appearance is not impaired.

[0038] Next, the operation of the oil mist removal device 100 will be described with reference to FIG. 11. FIG. 11 is a diagram showing a flowchart of the operation of the oil mist removal device 100 in the present embodiment. First, as shown in FIG. 11, in step S1, the oil mist removal device 100 rotates the suction fan 50 and the disk 70 by driving the motor 40. By the rotation of this suction fan 50, a negative pressure is generated, and the air containing oil mist and the like from the outside is sucked in through the intake port 12 and sent into the main body case 1.

[0039] Next, in step S2, the air sucked from the intake port 12 in step S1 is sucked by the suction fan 50. In such a case, the air sucked from the intake port 12 provided in the suction disk 52 of the suction fan 50 is accelerated by centrifugal force by the rotating blades 53. Therefore, the air discharged from the outer peripheral portion of the suction fan 50 collides with the inner peripheral surface 1c of the main body case 1. As a result, oil mist and the like in the air are separated, collected, and aggregated. This aggregated oil mist flows down under the influence of gravity and wind pressure, and is discharged to the outside through the drain port 15 on the bottom surface 1a of the main body case 1. In such a case, since the drain port 15 penetrates in the vertical direction z, the oil mist can be efficiently discharged to the outside under the influence of gravity.

[0040] Next, in step S3, the air discharged in step S2 passes through the rectifying plate 60. In such a case, the air discharged from the suction fan 50 in step S2 is swirling in a spiral. This air swirling in a spiral passes between the rectifying blades 65 provided on the rectifying plate 60 and is rectified.

[0041] Next, in step S4, the air rectified in step S3 passes through the disk 70. In such a case, the air rectified in step S3 flows perpendicularly to the disk 70. As a result, before passing through the slit 74 of the disk 70, it is struck by the crossbars 75 of the rotating disk 70, and the oil mist adheres to the crossbars 75 and is separated and collected. When this separated and collected oil mist accumulates and grows into a large-particle-size oil mist aggregate, it collides with the inner peripheral surface of the main body case 1 due to centrifugal force. Also, the air that has passed through the slit 74 is accelerated and discharged, and collides with the inner peripheral surface 1c of the main body case 1. Also, during this collision, oil mist is separated from the air and collected. The collected oil mist is discharged to the outside through the drain port 15 due to gravity and wind pressure. Also, when the air is not rectified in step S3, in step S4, since the flow of the air swirling in a spiral is synchronized with the rotation direction of the disk 70, when the air passes through the disk 70, it is difficult for the air to collide with the slit 74, so the collection effect of the oil mist is reduced.

[0042] Next, in step S5, the air that has passed through the disk 70 in step S4 is exhausted from the exhaust port 11. FIG. 12 is a diagram showing the flow of the air discharged from the exhaust port 11 in a cross section perpendicular to the x direction. The air flow a shows the flow when there is no return portion 24. Also, the air flow b shows the flow when there is a return portion 24. The air that has passed through the disk 70 in step S4 flows in the x direction while swirling spirally along the inner peripheral surface 1c of the main body case 1. In such a case, the removing portion 20 allows the air to pass through and captures the oil mist. Also, due to the presence of the return portion 24, the air swirling spirally along the inner peripheral surface 1c of the main body case 1 collides with the return portion 24, so that the air flow can be deflected. As a result, since the air becomes turbulent, it is possible to disperse the oil mist throughout the removing portion 20 without concentrating the oil mist on the upper part of the removing portion 20. For this reason, it is possible to reduce the load on the removing portion 20, so that the filter 2 can be made to last longer. Along with this, it is possible to suppress a decrease in the air volume of the oil mist removing device 100. Also, the oil mist adhering to the side surface 20a drips vertically in the z direction along the side surface 20a due to gravity, so that it is dispersed downward of the side surface 20a. For this reason, it is possible to equalize the load and lengthen the life of the filter 2.

[0043] Also, when the return surface 24a is perpendicular to the opening 20c, it becomes substantially perpendicular to the direction of the air swirling spirally along the inner peripheral surface 1c of the main body case 1. Therefore, a larger turbulent flow effect can be produced. As a result, it is possible to disperse the oil mist throughout the removal unit 20 without concentrating the oil mist at the upper part of the removal unit 20. For this reason, the load on the removal unit 20 can be reduced, so that the filter 2 can be made to last longer. Further, when the return portion 24 is formed along the side surface 20a of the cylindrical filter 2, the return portion 24 is perpendicular to the inner peripheral surface 1c, so that a larger turbulent flow effect can be produced. Also, when the return portion 24 is formed along the outer peripheral surface of the side surface 20a of the filter 2, the oil mist does not directly collide with the removal unit 20 near the opening 20c where the load is the largest, so that clogging of the filter 2 can be reduced. For this reason, the life of the filter 2 can be extended.

[0044] Next, the effects of the oil mist removal device 100 according to the embodiment of the present invention will be described. Table 1 is a table showing the experimental results of whether there is oil splashing from the exhaust port 11 when 100 ml / min of oily cutting oil is sucked into the oil mist removal device 100. As shown in Table 1, in the oil mist removal device 100 according to the embodiment of the present invention, Invention A in the case where the filter 2 and the return portion 24 are provided, Invention B in the case where the filter 2 is provided and the return portion 24 is not provided, Invention C in the case where neither the filter 2 nor the return portion 24 is provided, and an oil mist removal device described in Patent Document 1 were used to conduct an experiment on the presence or absence of oil splashing. As a result of this experiment, it was shown that only Invention A in the oil mist removal device 100 according to the embodiment of the present invention, in which the filter 2 and the return portion 24 are provided, has no oil splashing. From this, it was shown that the presence of the return portion 24 can suppress oil splashing.

Table 1

[0045] Table 2 shows the reduction rate of wind force when the oily cutting oil is sucked into the oil mist removal device 100 at 50 ml / sec. As shown in Table 2, a comparison was made between the case of using the oil mist removal device 100 according to the embodiment of the present invention and the case of using the oil mist removal device described in Patent Document 1. As a result, when 60 minutes had elapsed, in the case of using the oil mist removal device 100 according to the embodiment of the present invention, the reduction rate of wind force was -0.8%, while in the case of using the oil mist removal device described in Patent Document 1, the reduction rate of wind force was -7.9%. From this result, it was shown that, compared with the case of using the oil mist removal device described in Patent Document 1, when using the oil mist removal device 100 according to the embodiment of the present invention, the life of the filter 2 becomes longer and the reduction of wind force can be suppressed.

Table 2

[0046] As described above, the oil mist removal device 100 according to the embodiment of the present invention has been described. The oil mist removal device 100 according to the embodiment of the present invention includes a filter 2 that extends from the exhaust port 11 to the inside of the main body case 1 and has a circular cross-sectional shape perpendicular to the extending direction. Thereby, it becomes possible to easily remove the oil mist contained in the air discharged from the exhaust port 11. Further, for example, when the filter 2 is cylindrical, the surface area of the filter 2 becomes large, so that the life of the filter 2 can be extended. Further, since the filter 2 becomes longer in the extending direction, the oil mist captured by the filter 2 flows and diffuses in the extending direction, so that the filter 2 can be uniformly operated, and thus the life of the filter 2 can be extended. Further, for example, when the filter 2 is cylindrical, the attachment and detachment of the filter 2 becomes easy, so that the filter 2 can be easily replaced.

[0047] Although embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0048] 1 Main body case 1a Bottom surface 1b Ceiling 1c Inner peripheral surface 1d Front surface 2 Filter 3 Filter fixture 4 Nut 11 Exhaust port 12 Intake port 13 Main body 15 Drain port 15a Opening 16 Circulation rib 17 Drain pan 20 Removal part 20a Side surface 20b Bottom surface 20c Opening 21 Resin part 23 Edge part 24 Return part 24a Return surface 31 Fixed edge part 31a Opening 32 Pressing part 32a Inner frame part 32b Bottom edge part 40 Motor 41 First mounting plate 42 Second mounting plate 43 Rotating shaft 44 Connecting fitting 50 Suction fan 51 Mounting disc 52 Suction disc 53 Rotating blade 60 Rectifying plate 61 Rectifying substrate 62 Concentric disk 63 Concentric disk 64 Cross member 65 Rectifying vane 66 Upper side portion 67 Lower side portion 68 Connecting portion 69 Connecting portion 70 Disk 71 Disk 72 Annular member 73 Connecting portion 74 Slit 75 Cross member 78 Reinforcing plate 80 Exhaust guide plate 100 Oil mist removal device 101 First collection region 102 Second collection region

Claims

1. A main body case having a motor that rotates a suction fan for sucking air from an air inlet and an exhaust port provided above the rotation axis of the motor, and a filter extending from the exhaust port into the inside of the main body case and having a substantially circular cross-sectional shape perpendicular to the extending direction. An oil mist removal device characterized by the above.

2. Further comprising a return portion folded back from the exhaust port in the extending direction. The oil mist removal device according to claim 1, characterized by the above.

3. The return portion is formed along the substantially circular shape of the filter. The oil mist removal device according to claim 2, characterized by the above.

4. Further comprising a filter fixture provided inside the filter and having an inner frame portion extending in the extending direction along the inner peripheral surface of the filter. The oil mist removal device according to claim 1, characterized by the above.

5. The filter fixture has one or more pressing portions each comprising a linear bottom portion and the inner frame portion formed by folding back both ends of the bottom portion. The oil mist removal device according to claim 4, characterized by the above.

6. A disk provided in the main body case and having slits, and a drain port penetrating the bottom surface below the disk in the vertical direction in the main body case. The oil mist removal device according to claim 1, characterized by the above.

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