Magnetic separator

Abstract

The present invention provides a magnetic separator capable of preventing liquid adhering to the magnetic drum from flowing to the outside. [Solution] The magnet separator comprises a magnet drum, a drawing roll, and a scraping plate 15. The scraping plate has a scraping portion 40 that contacts the magnet drum, a first cutting portion 41, and a second cutting portion 42. The first cutting portion and the second cutting portion each form angles θ1 and θ2 of less than 45° with respect to imaginary line segments L1 and L2 that are extensions of the scraping portion. The cutting width W1 of the first cutting portion is 10 mm or more and extends to a position just before one end 21a of the magnet. The cutting width W2 of the second cutting portion 42 is 10 mm or more and extends to a position just before the other end 21b of the magnet. The vertical cutting amounts C1 and C2 of the first and second cutting portions are 1 mm or more and 5 mm or less, respectively.

Description

Technical Field

[0001] The present invention relates to a magnetic separator having a magnetic drum for removing magnetic substances contained in a liquid.

Background Art

[0002] When machining a metal material with a machine tool, various liquids such as grinding fluid, cutting fluid, and coolant are used. These liquids are discharged from the machine tool in a state containing foreign substances such as chips and metal powder generated by machining.

[0003] The liquid discharged from the machine tool is separated and removed from foreign substances such as chips and then returned to the machine tool for reuse. Therefore, various devices for collecting the liquid discharged from the machine tool and separating and removing foreign substances from the liquid are known. For example, a magnetic separator is known as a device for separating and removing magnetic substances from a liquid (for example, Patent Document 1).

[0004] One example of a magnetic separator includes a tank portion for containing a liquid containing a magnetic substance, a magnetic drum provided in the tank portion, a squeezing roll that rotates in a direction opposite to the magnetic drum in a state of being in contact with the outer peripheral surface of the magnetic drum, and a scraping plate for scraping off the magnetic substance attached to the outer peripheral surface of the magnetic drum.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] There is still room for improvement regarding the structure of the magnet separator. For example, there have been cases where a relatively large amount of the liquid adhering to the outer surface of the magnet drum flows into the box that collects the magnetic material. The inventors of this invention diligently researched the cause and obtained the following findings.

[0007] When the magnet drum rotates with liquid adhering to its outer surface, the liquid and magnetic material move toward the squeezing roll as the magnet drum rotates. When the liquid and magnetic material reach the contact point between the squeezing roll and the magnet drum, the liquid adhering to the outer surface of the magnet drum is squeezed out at the contact point, and the squeezed-out liquid flows downward along the outer surface due to its own weight.

[0008] Because the liquid has a certain degree of viscosity, some of the liquid squeezed out at the contact point does not flow down completely from the contact point, and the excess liquid may pass through both ends of the magnet drum and flow around to the front of the contact point. This tendency is more pronounced with higher viscosity liquids, and it has been confirmed that the liquid that flows around to the front of the contact point is scraped off near both ends in the width direction of the scraping plate, and a relatively large amount of liquid enters the magnetic material recovery box, etc. For this reason, it was desired to suppress such liquid flow in the magnet separator.

[0009] One of the objectives of this invention is to provide a magnetic separator that can prevent a portion of the liquid from flowing to an undesirable area. [Means for solving the problem]

[0010] A magnet separator according to one embodiment includes a tank section for containing a liquid containing a magnetic material, a magnet drum that rotates about an axis, a squeezing roll, and a scraping plate. The magnet drum has an outer circumferential surface for attracting the magnetic material, and magnets are arranged inside the outer circumferential surface. The squeezing roll is arranged parallel to the magnet drum and rotates in the opposite direction to the magnet drum when in contact with the outer circumferential surface. The scraping plate is positioned in front of the contact portion between the squeezing roll and the magnet drum in the direction of rotation of the magnet drum. Furthermore, the scraping plate has a first end located on one end side of the magnet drum and a second end located on the other end side of the magnet drum.

[0011] The scraping plate has a scraping portion extending in a direction along the axis when in contact with the outer circumferential surface, a first cut portion formed between the scraping portion and the first end, and a second cut portion formed between the scraping portion and the second end. The first cut portion forms a first angle of less than 45° with respect to a hypothetical first line segment along the scraping portion, and the distance from the outer circumferential surface increases from the scraping portion toward the first end. The second cut portion is formed between the scraping portion and the second end, forms a second angle of less than 45° with respect to a hypothetical second line segment along the scraping portion, and the distance from the outer circumferential surface increases from the scraping portion toward the second end.

[0012] Preferably, the cut width of the first cut portion in the direction along the first line segment is 10 mm or more, and the vertical cut amount at the first end is 1 mm or more and 5 mm or less. Also, preferably, the cut width of the second cut portion in the direction along the second line segment is 10 mm or more, and the vertical cut amount at the second end is 1 mm or more and 5 mm or less. In this embodiment, preferably, the cut width of the first cut portion is from the first end to a position just before one end of the magnet. Also, preferably, the cut width of the second cut portion is from the second end to a position just before the other end of the magnet.

[0013] The first angle and the second angle are preferably 5° or more and 20° or less, respectively. More preferably, the first angle and the second angle are preferably 5° or more and 10° or less, for example, around 7.5°. [Effects of the Invention]

[0014] According to this invention, it is possible to prevent a portion of the liquid adhering to the ends of the magnet drum from being scraped off by the scraping plate, and to prevent a portion of the liquid from flowing to undesirable locations. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a perspective view showing a cross-sectional view of a part of a magnet separator according to one embodiment. [Figure 2] Figure 2 is a front view of the magnetic separator shown in Figure 1. [Figure 3] Figure 3 is a perspective view of the scraping plate of the magnetic separator shown in Figure 1. [Figure 4] Figure 4 is a plan view of the scraping board shown in Figure 3. [Figure 5] Figure 5 is a schematic perspective view showing the magnet drum, squeezing roll, and scraping plate of the magnet separator shown in Figure 1. [Figure 6] Figure 6 is a schematic front view showing the magnet drum and scraping plate of the magnet separator shown in Figure 1. [Modes for carrying out the invention]

[0016] A magnetic separator according to one embodiment will be described below with reference to Figures 1 to 6. Note that this disclosure is merely an example, and the present invention is not limited to the embodiments described below. Modifications that are easily conceivable by those skilled in the art are naturally included within the scope of the disclosure. For clarity, the size, shape, and other characteristics of each part may be schematically represented in the drawings, differing from those of the actual embodiments.

[0017] In the embodiments shown in FIGS. 1 and 2, a first direction X, a second direction Y, and a third direction Z that are orthogonal to each other are defined. One side of the second direction Y may be referred to as the "front side", and one side of the third direction Z may be referred to as the "upper side".

[0018] In the present embodiment, a magnetic separator for mainly removing magnetic substances among foreign substances contained in a liquid such as grinding fluid discharged from a machine tool such as a grinding machine is disclosed. The liquid mentioned here includes water-soluble liquids and oil-based liquids. The magnetic substances are, for example, metal powders and chips. Magnetic substances have the property of being attracted by magnetic force.

[0019] A magnetic separator 10 is shown in FIG. 1. FIG. 1 is a perspective view showing a cross-section of a part of the magnetic separator 10. FIG. 2 is a front view of the magnetic separator 10 shown in FIG. 1.

[0020] As shown in FIGS. 1 and 2, the magnetic separator 10 includes a tank portion 11, a magnetic drum 12 provided in the tank portion 11, a drive portion 13 provided outside the tank portion 11, a throttle roll 14, and a scraping plate 15. The drive portion 13 rotates the magnetic drum 12 and the throttle roll 14.

[0021] In a plan view of the magnetic separator 10 seen from above, the inner region surrounded by the tank portion 11 is the inside of the tank portion 11. A storage portion 11a is formed in a part of the tank portion 11. A liquid containing magnetic substances is supplied to the storage portion 11a. As shown in FIG. 1, a middle plate 16 is installed in the storage portion 11a. A liquid flow path 17 is formed below the middle plate 16.

[0022] Adjacent to the storage section 11a, a clean liquid chamber 11b is formed for storing the clean liquid from which the magnetic material has been removed. An outlet 11c is formed in the bottom wall of the clean liquid chamber 11b. Between the storage section 11a and the clean liquid chamber 11b, a curved guide plate 18 is positioned along the outer circumferential surface 12a of the magnet drum 12. Between the guide plate 18 and the outer circumferential surface 12a of the magnet drum 12, a liquid flow section 19 with a relatively narrow flow path cross-sectional area is formed.

[0023] The magnet drum 12 has a cylindrical portion 12b that includes an outer circumferential surface 12a for attracting magnetic material. The cylindrical portion 12b rotates in the direction indicated by arrow R1 in Figure 1, about an axis A1 that extends in a first direction X. The axis A1 passes through the center of the shaft 20. The shaft 20 extends in the first direction X and is located at the center of rotation of the magnet drum 12.

[0024] A magnet 21 is positioned inside the outer circumferential surface 12a of the magnet drum 12. An example of a magnet 21 is a permanent magnet. The magnet 21 is fixed to a frame member or the like so that it is stationary relative to the rotating cylindrical portion 12b. The magnetic force generated by the magnet 21 forms a magnetic field region MA on the outer circumferential surface 12a of the magnet drum 12, in which magnetic materials can be attracted and a non-magnetic field region NMA in which magnetic materials can be released.

[0025] Each element constituting the magnetic drum 12, with the exception of the magnet 21, is formed from a non-magnetic material such as stainless steel. Note that each element may also include parts made from metal materials other than stainless steel or resin molded products.

[0026] The squeezing roll 14 is positioned parallel to the magnet drum 12. The squeezing roll 14 is located above the magnet drum 12 and includes a roll body 14a made of an elastic material such as hard rubber. The roll body 14a rotates about axis A2 of axis 14c (shown in Figures 1 and 2), which is parallel to axis A1 of the magnet drum 12.

[0027] With the outer surface of the squeezing roll 14 and the outer surface 12a of the magnet drum 12 in contact with each other at the contact portion 25, the squeezing roll 14 is rotated by the drive unit 13 in a second direction opposite to that of the magnet drum 12 (indicated by arrow R2 in Figure 1). As a result, the liquid and magnetic material adhering to the outer surface 12a of the magnet drum 12 are squeezed at the contact portion 25. Most of the squeezed liquid flows off the outer surface 12a before reaching the contact portion 25 and returns to the storage portion 11a.

[0028] A scraping plate 15 is provided on the magnet separator 10. The scraping plate 15 is responsible for scraping off magnetic material adhering to the outer surface 12a of the magnet drum 12. The scraping plate 15 is positioned in front of the contact portion 25 between the magnet drum 12 and the squeezing roll 14 in the direction of rotation of the magnet drum 12. Below the scraping plate 15 is a discharge plate 26 which functions as a chute to guide the magnetic material as it falls.

[0029] Figure 3 is a perspective view of the scraper plate 15. Figure 4 is a plan view of the scraper plate 15. Figure 5 is a schematic perspective view of the magnet drum 12, the squeezing roll 14, and the scraper plate 15. The scraper plate 15 has a first end 31 located on one end 12c side of the magnet drum 12 and a second end 32 located on the other end 12d side of the magnet drum 12. The scraper plate 15 is made of a metal plate such as stainless steel. The scraper plate 15 may also be made of a material other than metal, such as a resin material such as polyurethane or high molecular weight polyethylene.

[0030] The scraping plate 15 is provided over substantially the entire width of the cylindrical portion 12b of the magnet drum 12 in the first direction X. The scraping plate 15 has a scraping portion 40 that contacts the outer circumferential surface 12a of the magnet drum 12, a first cut portion 41 formed on the side of the first end 31, and a second cut portion 42 formed on the side of the second end 32. The scraping portion 40 is formed along the axis A1 of the magnet drum 12 over a length W3 (shown in Figure 4). The length W4 between one end 21a and the other end 21b of the magnet 21 is smaller than the length W3 of the scraping portion 40.

[0031] The scraping portion 40 extends in a direction along the axis A1 when in contact with the outer circumferential surface 12a of the magnet drum 12, and faces the non-magnetic field region NMA of the magnet drum 12. The scraping plate 15 of this embodiment has a first bent portion 43, a second bent portion 44, and a plurality of holes 45. The first bent portion 43 and the second bent portion 44 are effective in increasing the bending rigidity of the scraping plate 15. However, the shape of the scraping plate 15 may be other shapes, such as a flat plate without the first bent portion 43 and the second bent portion 44. The scraping portion 40 is fixed to the discharge plate 26 by screw members 46 (shown in Figures 1 and 2) inserted into the holes 45.

[0032] As shown in Figures 3 and 4, the first cut portion 41 is formed between the first end 31 and the scraping portion 40. The first cut portion 41 makes a first angle θ1 of less than 45° with respect to a hypothetical first line segment L1 along the scraping portion 40. That is, the first cut portion 41 has a shape in which the distance from the outer circumferential surface 12a of the magnet drum 12 increases from the scraping portion 40 toward the first end 31.

[0033] As shown in Figure 4, the cut width W1 of the first cut section 41, that is, the cut width W1 in the direction along the first line segment L1, is 10 mm or more. Moreover, the cut width W1 extends from the first end 31 to the position just before one end 21a of the magnet 21. Also, the vertical cut amount C1 at the first end 31 is 1 mm or more and 5 mm or less.

[0034] The second cut portion 42 is formed between the second end 32 and the scraping portion 40. The second cut portion 42 makes a second angle θ2 of less than 45° with respect to a hypothetical second line segment L2 along the scraping portion 40. In other words, the second cut portion 42 has a shape in which the distance from the outer circumferential surface 12a of the magnet drum 12 increases from the scraping portion 40 toward the second end 32.

[0035] As shown in Figure 4, the cut width W2 of the second cut section 42, that is, the cut width W2 in the direction along the second line segment L2, is 10 mm or more. Moreover, the cut width W2 extends from the second end 32 to the position just before the other end 21b of the magnet 21. Also, the vertical cut amount C2 at the second end 32 is 1 mm or more and 5 mm or less.

[0036] The first angle θ1 and the second angle θ2 are preferably in the range of 5° to 20°, respectively. More preferably, the first angle θ1 and the second angle θ2 are each between 5° and 10°, with 7.5° as the center value. An example of the first angle θ1 and the second angle θ2 is 7.5° each. If θ1 and θ2 are less than 5°, it becomes difficult to visually confirm whether the cut portions 41 and 42 have been processed during the process of processing the cut portions 41 and 42. If θ1 and θ2 exceed 20°, there is a greater possibility that the magnetic material scraped off by the scraping plate 15 will fall into the clean liquid chamber 11b through the gap between the cut portions 41 and 42 and the magnet drum 12.

[0037] Next, the operation of the magnetic separator 10 in this embodiment will be described. Liquid containing magnetic material, discharged from the liquid-using section of a machine tool or the like, flows into the storage section 11a from above the tank section 11, as indicated by arrow F1 in Figure 1. The liquid containing magnetic material that flows into the storage section 11a passes through the flow path 17 below the intermediate plate 16, as indicated by arrow F2 in Figure 1, and flows through the liquid flow section 19 along the outer circumferential surface 12a of the magnet drum 12, as indicated by arrow F3.

[0038] As the liquid containing the magnetic material flows through the liquid flow section 19, the magnetic material in the liquid is attracted to the outer surface 12a of the magnet drum 12. The magnetic material in the liquid is attracted to the magnetic field region MA on the outer surface 12a of the magnet drum 12 where the magnet 21 is located, and moreover, it is attracted to the area of ​​length W4 (shown in Figure 4) between one end 21a and the other end 21b of the magnet 21. In contrast, the magnetic force of the magnet 21 does not reach the vicinity of both ends corresponding to the first cut section 41 and the second cut section 42, so the magnetic material is not substantially attracted to those areas.

[0039] The liquid from which the magnetic material has been removed by the magnet drum 12 moves to the clean liquid chamber 11b, as indicated by arrow F4 in Figure 1, and is discharged from the outlet 11c. Because the magnet drum 12 is rotating in the first direction (indicated by arrow R1 in Figure 1), the magnetic material SG (schematically shown in Figures 2 and 6) adsorbed to the outer circumferential surface 12a of the magnet drum 12 moves out of the liquid surface as the magnet drum 12 rotates, moves towards the squeezing roll 14, and reaches the contact portion 25.

[0040] Figure 5 is a schematic perspective view showing the magnet drum 12, the squeezing roll 14, and the scraping plate 15. When the magnet drum 12 rotates, the liquid adhering to the outer surface 12a of the magnet drum 12 moves toward the contact portion 25 with the squeezing roll 14, as indicated by arrow B1 in Figure 5. Meanwhile, the liquid squeezed at the contact portion 25 flows down the outer surface 12a of the magnet drum 12, as indicated by arrow B2 in Figure 5.

[0041] Because the liquid adhering to the magnet drum 12 has a certain degree of viscosity, some of the liquid squeezed out at the contact portion 25 does not flow completely down from the contact portion 25 and, as shown by arrow B3 in Figure 5, may pass near one end 12c and the other end 12d of the magnet drum 12 and wrap around to the front side of the contact portion 25. This tendency is more pronounced with liquids of higher viscosity, and the liquid that wraps around to the front side of the contact portion 25 flows towards the ends of the scraping plate 15.

[0042] Figure 6 is a schematic front view of the magnet drum 12 and scraping plate 15 as seen from the front of the contact area 25. As the liquid that has wrapped around to the front of the contact area 25 moves near both ends of the magnet drum 12, areas S1 and S2 (shown as hatching in Figure 6) with a large amount of liquid buildup are created near both ends of the magnet drum 12. These areas S1 and S2 with a large amount of liquid buildup move towards the cutting portions 41 and 42 of the scraping plate 15.

[0043] Therefore, regions S1 and S2, where a large amount of liquid adheres, will pass near both ends of the scraping plate 15. However, since cut sections 41 and 42 are formed at both ends of the scraping plate 15, the regions S1 and S2, where a large amount of liquid adheres, will not be scraped off by the scraping plate 15. As a result, the flow of an undesirable amount of liquid along with the magnetic material over the discharge plate 26 is suppressed.

[0044] The magnetic material SG adhering to the outer surface 12a of the magnet drum 12 is scraped off by the scraping plate 15 as the magnet drum 12 rotates. The scraped magnetic material SG moves along the discharge plate 26 to a predetermined location, as shown by arrow F5 in Figures 1 and 6, and is collected. Because the angles θ1 and θ2 of the cut sections 41 and 42 are small (for example, 7 to 8°), the magnetic material SG scraped off by the scraping plate 15 is prevented from passing through the gap between the magnet drum 12 and the first cut section 41, or the gap between the magnet drum 12 and the second cut section 42, and falling into the clean liquid chamber 11b.

[0045] There may be workpieces 50, such as holes, formed by machining near both ends of the magnet drum 12. In this embodiment, the scraper plate 15 has a first cut portion 41 and a second cut portion 42 formed at both ends, so that the workpieces 50 (for example, the opening edge of a hole) do not come into contact with the scraper plate 15. This avoids problems caused by the scraper plate 15 coming into contact with the workpieces 50.

[0046] In implementing the magnet separator according to the present invention, the specific configurations of each element constituting the magnet separator, including the magnet drum, the squeezing roll, and the scraping plate, can be changed in various ways. Various embodiments can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be removed from all the components shown in the embodiments, or different components may be appropriately combined. [Explanation of Symbols]

[0047] 10...Magnetic separator, 11...Tank section, 12...Magnetic drum, 12a...Outer surface, A1...Axis, 14...Squeezing roll, 15...Scraping plate, 21...Magnet, 21a...One end, 21b...The other end, 25...Contact section, 31...First end, 32...Second end, 40...Scraping section, 41...First cutting section, 42...Second cutting section, L1, L2...Imaginary line segments, θ1...First angle, θ2...Second angle, W1, W2...Cut width, C1, C2...Long-direction cutting amount.

Claims

1. A tank section for containing a liquid containing a magnetic material, A magnet drum having an outer surface for attracting the magnetic material, with a magnet positioned inside the outer surface, and rotating about an axis, A drawing roll is positioned parallel to the magnet drum and rotates in the opposite direction to the magnet drum when in contact with the outer surface, A scraping plate is positioned in front of the magnet drum in the direction of rotation of the magnet drum with respect to the contact portion between the drawing roll and the magnet drum, and has a first end located on one end side of the magnet drum and a second end located on the other end side of the magnet drum. In a magnetic separator equipped with, The aforementioned scraping plate, A scraping portion extending in the direction along the axis when in contact with the outer circumferential surface, A first cut portion is formed between the scraping portion and the first end, forming a first angle of less than 45° with respect to a hypothetical first line segment along the scraping portion, and the distance from the outer surface increases toward the first end from the scraping portion, A second cut portion is formed between the scraping portion and the second end, forming a second angle of less than 45° with respect to a virtual second line segment along the scraping portion, and the distance from the outer surface increases toward the second end from the scraping portion, A magnetic separator characterized by having the following features.

2. In the magnetic separator according to claim 1, The cut width of the first cut portion in the direction along the first line segment is 10 mm or more and extends from the first end to a position just before one end of the magnet, and the vertical cut amount at the first end is 1 mm or more and 5 mm or less. A magnet separator wherein the cut width of the second cut portion in the direction along the second line segment is 10 mm or more and extends from the second end to a position just before the other end of the magnet, and the vertical cut amount at the second end is 1 mm or more and 5 mm or less.

3. In the magnetic separator according to claim 1, A magnetic separator in which the first angle and the second angle are 5° or more and 20° or less, respectively.

4. In the magnetic separator according to claim 1, A magnetic separator in which the first angle and the second angle are 5° or more and 10° or less, respectively.

Images