Magnetic foreign object capture device

Abstract

The present invention provides a magnetic foreign object capture device that can be properly installed inside the case of a vehicle's drive mechanism without requiring any special structure to be added to the case. [Solution] This magnetic foreign matter capture device 10 is installed inside the case of a vehicle drive mechanism, which has a flow path through which oil is stored or flows, and in which a member placed in the flow path is fixed by a magnetic fastener, and captures magnetic foreign matter contained in the oil. The entire device is made of a resin magnet capable of capturing magnetic foreign matter, and has a receiving recess 21 that accommodates a part of the fastener, and an attachment part 20 that is attracted to and attached to the fastener when a part of the fastener is accommodated in the receiving recess 21.

Description

Technical Field

[0001] The present invention relates to a magnetic foreign matter catcher that is fixed to a case of a vehicle drive mechanism having a flow path for storing or flowing oil and captures magnetic foreign matter contained in the oil.

Background Art

[0002] For example, in the case of a vehicle drive mechanism such as an automatic transmission (AT) of an automobile, a motor or a speed reducer used in an electric vehicle or a hybrid vehicle, etc., a flow path for storing or flowing oil for purposes such as lubrication and cooling is formed.

[0003] Such oil may contain magnetic foreign matter such as wear powder generated when gears mesh. Since this magnetic foreign matter may affect various performances of the vehicle, it is often captured by a predetermined magnetic foreign matter catcher.

[0004] For example, Patent Document 1 below describes a vehicle drive device including a drive case having a bottom wall with oil stored thereon, a speed reduction mechanism housed in the drive case, and a differential device that distributes the power of the speed reduction mechanism to left and right drive wheels.

[0005] On the bottom wall of the drive case, a protruding wall portion having a so-called doghouse shape with an open front side is provided, and an annular magnet is housed and held therein. Then, magnetic foreign matter is adsorbed from the oil in the drive case by the magnet housed and held in the protruding wall portion.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the vehicle drive system described in Patent Document 1, a special structure, a doghouse-like frame-shaped protruding wall, was required on the bottom wall of the drive case in order to install the magnet. In this case, inconveniences such as the need to secure space for the protruding wall inside the case and increased manufacturing costs arise.

[0008] Therefore, the object of the present invention is to provide a magnetic foreign object capture device that can be properly installed inside a vehicle drive mechanism case without providing a special structure to the case. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a magnetic foreign matter capture device for capturing magnetic foreign matter contained in oil, which is attached to the case of a vehicle drive mechanism having a flow path through which oil is stored or circulated, and a member disposed in the flow path is fixed by a magnetic fastener, wherein the entire magnetic foreign matter capture device is made of a resin magnet capable of capturing the magnetic foreign matter, and has a housing recess for housing a part of the fastener, and an attachment part which is attached to the fastener by attraction when the part of the fastener is housed in the housing recess. [Effects of the Invention]

[0010] In this invention, a part of the fixing device is housed in the recessed area, and the mounting part is attached by attraction to the fixing device. Therefore, a magnetic foreign object trap can be attached inside the case using a part of the fixing device, and the magnetic foreign object trap can be properly installed inside the case without providing a special structure to the case. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of a first embodiment of the foreign object capturing device according to the present invention. [Figure 2] This is a perspective view of the same foreign object capturing device, viewed from a different direction than in Figure 1. [Figure 3] This is a plan view of the foreign object capture device. [Figure 4] It is a cross-sectional view taken along the A-A line of FIG. 3. [Figure 5] It is a cross-sectional explanatory view of the state where the foreign object catcher is adsorbed and fixed to an existing fixture. [Figure 6] It is a schematic explanatory view of the case of the vehicle drive mechanism where the foreign object catcher is arranged and its internal structure. [Figure 7] It is a perspective view showing the second embodiment of the foreign object catcher according to the present invention. [Figure 8] It is a perspective view of the foreign object catcher when viewed from a direction different from that of FIG. 7. [Figure 9] It is a front view of the foreign object catcher. [Figure 10] It is a perspective view showing the third embodiment of the foreign object catcher according to the present invention. [Figure 11] It is a perspective view of the foreign object catcher when viewed from a direction different from that of FIG. 10. [Figure 12] It is a cross-sectional view taken along the B-B line of FIG. 11. [Figure 13] It is a cross-sectional explanatory view of the state where the foreign object catcher is adsorbed and fixed to an existing fixture. [Figure 14] It is an explanatory view showing the state of magnetic field lines in the foreign object catcher. [Figure 15] It is a perspective view showing the fourth embodiment of the foreign object catcher according to the present invention. [Figure 16] It is a cross-sectional explanatory view of the state where the foreign object catcher is adsorbed and fixed to an existing fixture.

Embodiments for Carrying Out the Invention

[0012] (First Embodiment of Magnetic Foreign Object Catcher) Hereinafter, referring to FIGS. 1 to 6, the first embodiment of the magnetic foreign object catcher according to the present invention will be described.

[0013] As shown in Fig. 5, this magnetic foreign object catcher 10 (hereinafter also simply referred to as "catcher 10") has a flow path in which oil is stored or circulated, and a member (in this embodiment, an oil strainer 3 described later) disposed in the flow path is fixed by a fixing tool having magnetism (in this embodiment, a bolt 6 described later). It is attached to the case 1 of the vehicle drive mechanism configured to be fixed by a fixing tool, and is for capturing magnetic foreign objects contained in the oil.

[0014] Examples of the case of the vehicle drive mechanism include cases of motors, speed reducers, etc. used in automotive ATs, electric vehicles, hybrid vehicles, etc. Fig. 6 shows an outline of such a case 1 and its internal structure.

[0015] That is, a plurality of gears such as 2a, 2b, 2c of a speed reducer or a motor are arranged in a meshed state at a predetermined location in the case 1, and an oil strainer 3 for filtering oil is arranged on the bottom side of the case 1. The oil stored at the bottom of the case 1 is filtered by the oil strainer 3, and then sent above the case through a flow path not shown by an oil pump 4, and dripped onto the plurality of gears 2a, 2b, 2c through an oil garter 5 and used for lubricating the gears 2a, 2b, 2c. Thereafter, the oil flows to the bottom of the case 1 and is stored, filtered again by the oil strainer 3, sent above the case by the oil pump, and circulated in the case.

[0016] This catcher 10 is entirely made of a resin magnet capable of capturing magnetic foreign objects, and has a housing recess 21 for housing a part of an existing magnetic adsorbing fixing tool for fixing a member disposed in the case 1 to the case 1, and an attachment portion 20 that is attached by being adsorbed to the fixing tool when a part of the fixing tool is housed in the housing recess 21.

[0017] The resin magnet is also called a plastic magnet, a plamag, etc., and is formed by mixing magnetic powder into synthetic resin and injection molding it into a predetermined shape, and has a predetermined magnetic force (magnetic adsorption force).

[0018] In this embodiment, the fastener consists of a shaft portion 7 with screw grooves formed on its outer circumference and a head portion 8 connected to the base end of the shaft portion 7, and is a bolt 6 having magnetism (or magnetic attraction). In this embodiment, the head portion 8 of the bolt 6 has a hexagonal shape on its outer circumference, and the bolt 6 is a so-called hexagonal bolt.

[0019] Furthermore, a fixing boss (not shown) for securing the oil strainer is provided on the bottom side of case 1. A screw threading hole (not shown) is formed in this fixing boss. In addition, a screw insertion hole (not shown) is formed at a predetermined location on the oil strainer 3.

[0020] Then, the oil strainer 3 is positioned so that its screw insertion hole aligns with the screw threading hole of the oil strainer's fixing boss. The shaft portion 7 of the bolt 6 is then passed through the screw insertion hole and screwed into the screw threading hole, thereby fixing the oil strainer 3 to the bottom side of the case 1 via the bolt 6, which acts as a fixing device (see Figure 5).

[0021] In this embodiment, the oil strainer 3 constitutes a "component" in the present invention, which is fixed to the case 1. Furthermore, the bolt 6, which is a fastener, constitutes a "fastener" in the present invention, and the head 8 that makes up the bolt 6 constitutes a "part of the fastener" in the present invention.

[0022] As shown in Figures 1 and 4, the mounting portion 20 of the capture device 10 has a substantially cylindrical peripheral wall portion 22 and a substantially disc-shaped closing wall portion 23 that closes the opening at one axial end of the peripheral wall portion 22, and a receiving recess 21 is formed inside these peripheral wall portion 22 and closing wall portion 23.

[0023] Furthermore, as shown in Figures 2 and 4, an annular recess 25, which has an annular recess shape, is formed on the inner surface side (the side facing the receiving recess 21) of the closing wall portion 23.

[0024] Furthermore, the inner circumferential shape of the receiving recess 21 is shaped to match the outer circumferential shape of the bolt head 8. Specifically, the outer surface of the peripheral wall portion 22 is circular in the radial direction, but the inner surface in the radial direction, that is, the inner circumference of the receiving recess 21 in the radial direction, has multiple continuous groove-like grooves 27 extending in a roughly V-shape along the axial direction of the peripheral wall portion 22, extending along the entire circumference of the peripheral wall portion 22.

[0025] Then, by inserting the head 8 of the bolt 6 into the receiving recess 21, each corner of the head 8 engages with a predetermined location in the groove 27, and the head 8 is housed and held in the receiving recess 21 in a state where it is prevented from rotating in the radial direction of the receiving recess 21.

[0026] Furthermore, an oil receiving portion 30 for receiving oil is provided protruding from the outer surface of the mounting portion 20. In the case of the oil receiving portion 30 of this embodiment, the mounting portion 20 has a shape in which a recessed portion 32 for receiving oil partially protrudes in the circumferential direction of the mounting portion 20 from the side opposite to the side where the receiving recess 21 is provided.

[0027] Furthermore, the oil receiving section 30 has an oil inlet 33 for allowing oil to flow into the concave section 32, an oil outlet 34 for allowing oil to flow out of the concave section 32, and an expanding section 37 for widening the oil inlet.

[0028] More specifically, a roughly semi-cylindrical protruding wall portion 35 protrudes from the peripheral edge of the outer surface (opposite to the inner surface facing the receiving recess 21) of the closing wall portion 23 that constitutes the mounting portion 20, with a length along the circumferential direction of the mounting portion 20 being approximately half the circumference (total length) of the closing wall portion 23. The outer surface of the protruding wall portion 35 is a continuous surface without any steps (flush surface) with respect to the outer surface of the peripheral wall portion 22 of the mounting portion 20.

[0029] Furthermore, a tip wall portion 36 is provided on the tip side of the protruding wall portion 35, which is positioned parallel to the closed wall portion 23 at a predetermined distance. These walls 35 and 36 form a concave portion 32 on the inside, and an oil inlet 33 is provided on both circumferential ends of the protruding wall portion 35, forming a substantially semi-cylindrical frame-shaped oil receiving portion 30.

[0030] Furthermore, a pair of roughly rectangular oil outlets 34, 34 are formed at the bottom 35a of the protruding wall portion 35, facing the oil inlet 33, and extending circumferentially.

[0031] Furthermore, a guide projection 38 is provided on the inner surface (the surface facing the concave portion 32) of the bottom portion 35a of the protruding wall portion 35, between the pair of oil outlets 34, 34. This guide projection 38 has a roughly triangular shape with both sides facing the oil outlets 34, 34, and guides the oil received in the concave portion 32 to the oil outlets 34, 34, making it easier for the oil to flow out of the oil outlets 34.

[0032] Furthermore, at the circumferential ends of the protruding wall portion 35, near the tip wall portion 36, an expanded portion 37 extends outward at an angle in a roughly trumpet shape toward the opposite side of the oil outlet 34 from the outer peripheral edge of the oil inlet 33 and from the outer peripheral edge of the tip wall portion 36 of the oil inlet 33.

[0033] This expanded portion 37 communicates with the oil inlet 33, widening the width and opening area of ​​the oil inlet 33, and also functions as an inflow guide for oil flowing into the concave portion 32 through the oil inlet 33, making it easier for oil to flow into the concave portion 32.

[0034] Furthermore, all parts of the capture device 10 described above (mounting portion 20, peripheral wall portion 22 and closing wall portion 23 constituting the mounting portion 20, oil receiving portion 30, protruding wall portion 35 and tip wall portion 36 constituting the oil receiving portion 30, expanding portion 37, guide projection portion 38, etc.) are integrally formed from the aforementioned plastic magnet or the like.

[0035] (modified version) The shapes, structures, and layouts of the mounting portion, receiving recess, peripheral wall portion, closing wall portion, oil receiving portion, oil receiving portion, protruding wall portion, tip wall portion, expanding portion, guide projection, etc., that constitute the magnetic foreign object trapping device of the present invention are not limited to the above embodiments.

[0036] For example, the outer surface of the peripheral wall of the mounting portion may be polygonal or elliptical. Furthermore, the inner circumferential shape of the receiving recess may be formed as a circle, a polygon such as a hexagon or octagon, and can be appropriately selected to correspond to the shape of a part of the fastener (the bolt head). However, it is preferable that the inner circumferential shape of the receiving recess conforms to the outer circumferential shape of a part of the fastener.

[0037] Furthermore, the protruding wall portion constituting the oil receiving section may be made into an arc shape, for example, smaller than or larger than half the circumference of the closing wall portion, rather than a semi-cylindrical shape. In addition, the tip wall portion constituting the oil receiving section may be inclined to gradually widen toward the oil inlet side relative to the closing wall portion of the mounting section.

[0038] Furthermore, the oil receiving section may be configured with one or more rib-like protruding pieces that do not have a concave portion (this will be explained in the embodiments described later).

[0039] The oil outlets formed in the oil receiving section may be one or three or more, and their shape may be circular, elliptical, polygonal, or the like.

[0040] Furthermore, the fastener in this embodiment is a bolt 6, which fixes the oil strainer 3, a component placed inside the case 1, to the case 1. However, the fastener can be anything that can fix a component placed inside the case to the case and is magnetic. Moreover, if the fastener is a bolt, the head may be a so-called hexagonal socket head bolt with a circular outer circumference and a hexagonal hole inside, or a bolt with a square or octagonal outer circumference.

[0041] Furthermore, multiple dimple-shaped recesses forming hemispherical concave shapes, inverted dimple-shaped protrusions forming hemispherical convex shapes, and other irregularities such as roughly cylindrical, roughly rectangular, or roughly trapezoidal shapes may be provided on the outer surface of the mounting portion 20 and the outer and inner surfaces of the oil receiving portion 30. In this case, the surface area of ​​the mounting portion 20 and the oil receiving portion 30 can be increased by the multiple irregularities, thereby increasing their magnetic force and further improving the effect of capturing magnetic foreign matter.

[0042] (Effects and Benefits) Next, the effects and benefits of the capture device 10, which has the above configuration, will be explained.

[0043] As shown in Figure 5, by fixing this capture device 10 to the case 1 of the vehicle drive mechanism, it can adsorb and capture (or remove) magnetic foreign matter contained in the oil flowing through the flow path R.

[0044] Furthermore, the capture device 10 has a receiving recess 21 for accommodating a part of an existing magnetically adsorbent fixing device (in this case, the head 8 of the bolt 6), and a mounting portion 20 that is attached to the fixing device by being attracted to it when the part of the fixing device is accommodated in the receiving recess 21.

[0045] In other words, when the head 8 of the bolt 6 is inserted into the receiving recess 21 of the mounting portion 20, each corner of the head 8 engages with a predetermined location in the grooved groove 27 on the inner circumference of the receiving recess 21, thereby preventing the head 8 from rotating in the radial direction of the receiving recess 21 and holding it in place. At the same time, the magnetic attraction force of the capture device 10, particularly the magnetic attraction force from the mounting portion 20, causes the mounting portion 20 to be attracted to the head 8 of the bolt 6, thereby fixing the capture device 10 to the bolt 6, which is an existing fastener.

[0046] In this way, the capture device 10 can be attached inside the case 1 using a part of the fixing device, so the capture device 10 can be properly installed inside the case 1 without providing any special structure to the case 1.

[0047] Furthermore, the capture device 10 can be installed in the case 1 with a simple operation of accommodating a part of the fastener in the receiving recess 21, thereby improving the ease of installation of the capture device 10 to the case 1. In addition, since no special structure is required to install the capture device 10 in the case 1, the manufacturing cost of the case 1 can be reduced.

[0048] Furthermore, in this embodiment, the fastener is a bolt 6, a part of the fastener is the head 8 of the bolt 6, and the inner circumferential shape of the receiving recess 21 is shaped to match the outer circumferential shape of the head 8. According to this embodiment, the head 8 of the bolt 6, which is the fastener, can be effectively utilized to install the capture device 10 in the case 1.

[0049] Furthermore, since the inner circumferential shape of the receiving recess 21 conforms to the outer circumferential shape of the head 8, the magnetic attraction force from the entire inner circumferential part of the receiving recess 21 is appropriately exerted over the entire outer circumferential part of the head 8 of the bolt 6. As a result, the attraction strength of the retaining device 10 to the head 8 of the bolt 6 is improved, and even if the retaining device 10 tries to come off the head 8, the inner circumferential part of the receiving recess 21 catches on the outer circumferential part of the head 8, making it difficult to detach, thus making it difficult for the retaining device 10 to come off the head 8.

[0050] Furthermore, in this embodiment, the component is an oil strainer 3 arranged inside the case 1 to filter the oil, and the fixing device is a bolt 6 for fixing the oil strainer 3 to the case 1 or a component other than the oil strainer 3, with part of the fixing device being the head 8 of the bolt 6.

[0051] According to the above embodiment, the fixing device is a bolt 6 for fixing the oil strainer 3 to the member, so the capture device 10 fixed to the bolt 6 will be installed on the oil strainer 3 itself or near the oil strainer 3. As a result, magnetic foreign matter contained in the oil can be efficiently captured before or after filtration by the oil strainer 3, and clogging of the oil strainer 3 can be effectively suppressed.

[0052] Furthermore, in this embodiment, an oil receiving portion 30 for receiving oil is provided protruding from the outer surface of the mounting portion 20. According to the above embodiment, by providing the oil receiving portion 30 protruding from the outer surface of the mounting portion 20, the surface area of ​​the capture device 10 can be increased by the amount of the oil receiving portion 30, and magnetic foreign matter contained in the oil can be captured more effectively.

[0053] Furthermore, in this embodiment, the oil receiving portion 30 has a shape that partially protrudes in the circumferential direction of the mounting portion 20 from the side of the mounting portion 20 opposite to the side where the receiving recess 21 is provided, and has a concave portion 32 that receives oil, and also has an oil inlet 33 for allowing oil to flow into the concave portion 32 and an oil outlet 34 for allowing oil to flow out of the concave portion 32.

[0054] According to the above embodiment, the concave portion 32 provided in the oil receiving portion 30 makes it easier for magnetic foreign matter contained in the oil to come into contact with the inner surface of the oil receiving portion 30, thereby enabling more efficient capture of magnetic foreign matter contained in the oil.

[0055] Furthermore, in this embodiment, the oil receiving section 30 has an expanding section 37 that widens the oil inlet 33. According to this embodiment, since the oil receiving section 30 has an expanding section 37 that widens the oil inlet 33, it becomes easier to receive oil into the concave section 32.

[0056] (Second embodiment of a magnetic foreign object capture device) A second embodiment of the magnetic foreign object capture device according to the present invention will be described below with reference to Figures 7 to 9. Parts substantially identical to those in the previous embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0057] The magnetic foreign object trapping device 10A in this embodiment (hereinafter also simply referred to as "trapping device 10A") differs from the above embodiment mainly in the shape of the oil receiving portion 30A.

[0058] In other words, the oil receiving portion 30A in this embodiment consists of a rib-like projection 39 that protrudes from the mounting portion 20 on the side opposite to the side where the receiving recess 21 is provided.

[0059] More specifically, as shown in Figures 7 and 9, the oil receiving portion 30A is formed by a plurality of thin, rib-shaped protruding pieces 39 that extend radially outward from the radial center of the closing wall portion 23, which constitutes the mounting portion 20. The protruding pieces 39 are four ribs that extend at equal intervals from the radial center of the closing wall portion 23, and as shown in Figure 9, when the capture device 10A is viewed from the front, the oil receiving portion 30A as a whole has a roughly cross shape.

[0060] The protruding pieces may be, for example, three or five or more ribs extending radially from the radial center of the outer surface of the closure wall 23, or one or more ribs arranged on the outer surface of the closure wall 23 so as to cross the closure wall 23 radially, as long as they are ribs provided in the middle of the oil flow path.

[0061] Furthermore, as shown in Figure 8, the radial inner surface of the peripheral wall portion 22, that is, the inner circumference 26 of the receiving recess 21, has a regular hexagonal shape, so that the head of a so-called hexagonal bolt fits into it.

[0062] In this embodiment, the oil receiving portion 30A consists of a rib-like projection 39 that protrudes from the mounting portion 20 on the side opposite to the side where the receiving recess 21 is provided. This allows for an improved magnetic foreign matter capture effect with a relatively simple structure, while also reducing the manufacturing cost of the capture device 10A.

[0063] (Third embodiment of a magnetic foreign object capture device) A third embodiment of the magnetic foreign object capture device according to the present invention will be described below with reference to Figures 10 to 14. Parts substantially identical to those in the previous embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0064] The magnetic foreign object capture device 10B of this embodiment (hereinafter also simply referred to as "capture device 10B") has a mounting portion 20B that differs from the mounting portion 20 of the first and second embodiments.

[0065] In other words, while the mounting portion 20 of the first and second embodiments has a closed wall portion 23, the mounting portion 20B of this embodiment differs in that it has a peripheral wall portion 22B that surrounds the outer circumference of the head of the fastener, and has a cylindrical shape with both ends in the axial direction open. In addition, a receiving recess 21 is provided inside the peripheral wall portion 22B (see Figure 11). As shown in Figure 12, the direction along the axis C of the cylindrical peripheral wall portion 22B is defined as the "axial direction".

[0066] Furthermore, the fastener in this embodiment is a bolt 6B with a hexagonal outer circumference of the head 8. A flange portion 9 that extends in an annular shape is provided protruding from the base outer circumference of the head 8 of this bolt 6B. The tip surface 9a of the flange portion 9 (the surface facing the tip side of the head 8) is an inclined surface that gradually increases in thickness from its radial outer edge toward the tip (top) of the head 8.

[0067] Furthermore, the mounting portion 20B of this embodiment has an opening 41a on the axial base end 41 side of the peripheral wall portion 22B, and an opening 43a on the axial tip end 43 side of the peripheral wall portion 22B, resulting in a cylindrical structure with openings at both axial ends (base end and tip).

[0068] As shown in Figure 11, the inner circumferential shape of the receiving recess 21 is a roughly hexagonal shape that matches the outer circumferential shape of the head 8 of the bolt 6B. In addition, a roughly circular through hole 45 is formed on the axial side of the circumferential wall portion 22B toward the tip portion 43, communicating with the opening 43a on the tip portion 43 side. The inner diameter of the through hole 45 is smaller than the minimum dimension of the inner circumferential shape of the receiving recess 21.

[0069] Furthermore, as shown in Figure 13, a groove-shaped engaging portion 47 is provided inside the opening 41a on the axial base end 41 side of the peripheral wall portion 22B, which engages with the flange portion 6 of the bolt 6B when the flange portion 9 of the bolt 6B is received.

[0070] Specifically, the engaged portion 47 has an inner circumferential surface 47a with a constant diameter that is circular in shape and communicates with the opening 41a on the base end 41 side of the peripheral wall portion 22B, and a bottom surface 47b that slopes from the axial tip of the inner circumferential surface 47a toward the axial tip 43 side of the peripheral wall portion 22B, and toward the radially inward side of the peripheral wall portion 22B, so as to gradually decrease in diameter.

[0071] Furthermore, the inclination angle of the bottom surface 47b of the engaged portion 47 with respect to the axis C is set to match the inclination angle of the tip surface 9a of the flange portion 9 of the bolt 6B with respect to the bolt axis. In other words, the engaged portion 47 has a shape that matches the tip surface 9a of the flange portion 9, and when the head 8 is housed in the receiving recess 21 and the flange portion 9 is engaged with the engaged portion 47, the bottom surface 47b is formed which the tip surface 9a abuts.

[0072] Furthermore, a protruding portion 49 extends outward from the outer circumference of the axial tip portion 43 of the peripheral wall portion 22B in a direction intersecting the axial direction.

[0073] In this embodiment, a substantially annular projection 49 extends outward in a direction perpendicular to the axial direction, i.e., radially outward, from the outer circumference of the axial tip 43 of the peripheral wall portion 22B. The projection 49 is provided such that its axial (thickness) tip surface is flush with the leading edge surface of the axial tip 43 of the peripheral wall portion 22B, without any irregularities.

[0074] Furthermore, as shown in Figure 13, the length L1 of the peripheral wall portion 22B from the axial base end 41b to the tip end 43b is set to be greater than the length L2 of the head 8 from the axial base end 41b of the peripheral wall portion 22B to the tip end 8a of the head 8 when the head 8 is housed in the housing recess 21.

[0075] Specifically, the minimum length (shortest distance) from the base end 41b of the axial base end 41 of the peripheral wall portion 22B to the tip end 43b of the tip portion 43 is the "length L1" described above, and the minimum length (shortest distance) from the base end 41b of the axial base end 41b of the peripheral wall portion 22B to the tip end 8a of the head portion 8 when the head portion 8 is housed in the housing recess 21 is the "length L2" described above.

[0076] Then, with the head 8 of the bolt 6B housed in the receiving recess 21, and in this case with the flange portion 9 of the bolt 6B engaged with the engaged portion 47 of the peripheral wall portion 22B (see Figure 13), the setting is such that L1 > L2.

[0077] The length L1 of the peripheral wall portion may be set to be the same as the length L2 of the bolt head, which is the fastener (this will be explained in the fourth embodiment described later).

[0078] (Effects and Benefits) Next, the effects and benefits of the capture device 10B, which has the above configuration, will be explained.

[0079] In other words, in this embodiment, the mounting portion 20B has a peripheral wall portion 22B that surrounds the outer circumference of the head portion 8, and a receiving recess 21 is provided inside the peripheral wall portion 22B. The length L1 of the peripheral wall portion 22B from the axial base end 41b to the tip end 43b is set to be greater than the length L2 of the head portion 8 from the axial base end 41b of the peripheral wall portion 22B to the tip end 8a of the head portion 8 when the head portion 8 is housed in the receiving recess 21 (see Figure 13).

[0080] According to the above embodiment, since the length L1 of the peripheral wall portion 22B is set to be greater than the length L2 of the head portion 8, the outer circumference of the head portion 8 can be reliably covered by the peripheral wall portion 22B, and the detachment force of the peripheral wall portion 22B from the head portion 8 (the force required when the mounting portion 20B detaches from a part of the fastener) can be increased.

[0081] Furthermore, since the length L1 of the peripheral wall portion 22B is set as described above, the volume of the peripheral wall portion 22B can be increased compared to the case where the length L1 of the peripheral wall portion is smaller than the length L2 of the head portion. As a result, the amount of magnetic material (magnetic powder) used to form the resin magnet can be increased, thereby increasing the magnetic attraction force of the entire mounting portion 20B, making it less likely for the mounting portion 20B to detach from the head 8 of the fixing device, and also improving the efficiency of capturing magnetic foreign matter contained in the oil.

[0082] Furthermore, in this embodiment, the peripheral wall portion 22B is cylindrical with both ends in the axial direction open.

[0083] According to the above embodiment, since the peripheral wall portion 22B of the mounting portion 20B is cylindrical with both ends in the axial direction open, as shown in Figure 14, a portion of the magnetic field lines M of the resin magnet are oriented along the axial direction of the peripheral wall portion 22B and are oriented to circulate at both ends in the axial direction, thus preventing the magnetic field lines M from oriented radially inward of the peripheral wall portion 22B. In addition, magnetic domains (regions where magnetic moments are aligned in one direction) are located on the axial end face of the peripheral wall portion 22B (in this case, the end face on the tip portion 43 side).

[0084] Therefore, the magnetic attraction force of the resin magnet can be concentrated on the axial end face of the peripheral wall portion 22B. As a result, the release force of the mounting portion 20B can be increased, and the efficiency of capturing magnetic foreign matter can be further improved.

[0085] Furthermore, in this embodiment, a flange portion 9 is provided protruding from the outer circumference of the head 8 of the bolt 6B, which is a fastener, and a groove-shaped engaging portion 47 is provided inside the opening 41a on the axial base end 41 side of the peripheral wall portion 22B, which engages with the flange portion 9 when the flange portion 9 is received.

[0086] According to the above embodiment, when the head 8 is housed in the receiving recess 21 of the mounting portion 20B, the flange portion 9 is engaged with the groove-shaped engaging portion 47 in a received state. Therefore, when vibrations occur, the flange portion 9 will come into contact with the inside of the engaging portion 47 (inner circumferential surface 47a or bottom surface 47b), making it difficult for the mounting portion 20B to come off the head 8 of the bolt 6.

[0087] Furthermore, in this embodiment, a protruding portion 49 extends outward from the outer circumference of the axial tip portion 43 of the peripheral wall portion 22B in a direction intersecting the axial direction.

[0088] According to the above embodiment, since the protruding portion 49 with the above configuration is provided on the peripheral wall portion 22B, as shown in Figure 14, the magnetic field lines M of the resin magnet can be spread radially outward from the peripheral wall portion 22B by the amount of the protruding portion 49. As a result, the area for capturing magnetic foreign matter contained in the oil can be increased by the protruding portion 49 in addition to the axial tip portion 43 of the peripheral wall portion 22B, thereby increasing the capture efficiency of magnetic foreign matter.

[0089] Furthermore, since the volume of the peripheral wall portion 22B can be increased by the amount of the protruding portion 49, it becomes possible to increase the amount of magnetic material used to form the resin magnet. As a result, the magnetic attraction force of the entire mounting portion 20B can be further increased, making it less likely for the mounting portion 20B to detach from the head 8 of the bolt 6.

[0090] Furthermore, in this embodiment, the inclination angle of the bottom surface 47b of the engaged portion 47 with respect to the axis C is set to match the inclination angle of the tip surface 9a of the flange portion 9 of the bolt 6B with respect to the bolt axis.

[0091] According to the above embodiment, when the head 8 is inserted into the receiving recess 21 of the mounting portion 20B and housed, the tip surface 9a of the flange portion 9 abuts against the bottom surface 47b of the engaged portion 47 without any gaps, and the flange portion 9 engages with the engaged portion 47. As a result, the capture device 10B can be mounted inside the case 1 with minimal play and with high precision and stability.

[0092] (Fourth embodiment of a magnetic foreign object capture device) A fourth embodiment of the magnetic foreign object capture device according to the present invention will be described below with reference to Figures 15 and 16. Parts substantially identical to those in the previous embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0093] In this embodiment, the magnetic foreign object capture device 10C (hereinafter also simply referred to as "capture device 10C") has a different length for the peripheral wall portion 22C of the mounting portion 20C compared to the length for the peripheral wall portion 22B of the third embodiment.

[0094] Specifically, the mounting portion 20C in this embodiment does not have a through hole 45 or a protruding portion 49 as provided in the mounting portion 20B of the third embodiment, but rather has a peripheral wall portion 22C with both axial ends open.

[0095] In this embodiment, as shown in Figure 16, the axial length L1 of the peripheral wall portion 22C from the base end 41b to the tip end 43b is set to be the same as the length L2 of the head 8 from the axial base end 41b of the peripheral wall portion 22B to the tip end 8a of the head 8 when the head 8 is housed in the housing recess 21. In other words, the peripheral wall portion 22C in this embodiment has a shorter axial length than the peripheral wall portion 22B in the third embodiment.

[0096] In the fourth embodiment of the above configuration, since the length L1 of the peripheral wall portion 22C is set as described above, the volume of the peripheral wall portion 22 can be increased compared to the case where the length L1 of the peripheral wall portion 22 is smaller than the length L2 of the head portion 8. This increases the amount of magnetic material used to form the resin magnet, enhances the magnetic attraction force of the entire mounting portion 20C, makes it less likely for the mounting portion 20C to detach from the head portion 8 of the fixture, and improves the efficiency of capturing magnetic foreign matter contained in the oil.

[0097] Furthermore, the present invention is not limited to the embodiments described above, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention. [Explanation of symbols]

[0098] 1...Case, 3...Oil strainer, 6, 6B...Bolt (fixing device), 8...Head, 10, 10A, 10B, 10C...Magnetic foreign object capture device (capture device), 20, 20B, 20C...Mounting part, 21...Accommodating recess, 22, 22B, 22C...Peripheral wall part, 26...Inner circumference, 30, 30A...Oil receiving part, 32...Concave part, 33...Oil inlet, 34...Oil outlet, 35...Protruding wall part, 39...Protruding piece

Claims

1. A magnetic foreign matter capture device for capturing magnetic foreign matter contained in oil, which is installed inside the case of a vehicle drive mechanism having a flow path through which oil is stored or circulated, and in which a member placed in the flow path is fixed by a magnetic fastener, The entire magnetic foreign object capture device consists of a resin magnet capable of capturing the magnetic foreign object. A recess for housing a part of the aforementioned fastener, A magnetic foreign object capture device characterized by having a mounting portion which is attached to the fixing device by suction when a part of the fixing device is housed in the receiving recess.

2. The fastener is a bolt, and a part of the fastener is the head of the bolt. The magnetic foreign object trapping device according to claim 1, wherein the inner circumferential shape of the receiving recess is shaped to match the outer circumferential shape of the head.

3. The aforementioned member is an oil strainer disposed inside the case for filtering the oil, The magnetic foreign object trapping device according to claim 1, wherein the fixing device is a bolt for fixing the oil strainer to the case or a member other than the oil strainer, and a part of the fixing device is the head of the bolt.

4. The mounting portion has a peripheral wall portion that surrounds the outer circumference of the head portion, and the receiving recess is provided on the inside of the peripheral wall portion. The magnetic foreign object trapping device according to claim 2, wherein the minimum length L1 from the base end to the tip in the axial direction of the peripheral wall portion is set to be the same as or greater than the minimum length L2 of the head from the base end to the tip of the head in the axial direction of the peripheral wall portion when the head is housed in the receiving recess.

5. The magnetic foreign object capturing device according to claim 4, wherein the peripheral wall portion is cylindrical with both ends in the axial direction open.

6. A flange portion is provided protruding from the outer circumference of the head of the bolt, which is the fastening device. The magnetic foreign object trapping device according to claim 5, wherein a groove-shaped engaging portion is provided on the inside of the opening on the axial base end side of the peripheral wall portion, which engages with the flange portion when the flange portion is received.

7. The magnetic foreign object capturing device according to claim 5 or 6, wherein a protruding portion extends outward in a direction intersecting the axial direction from the outer circumference of the axial tip of the peripheral wall portion.

8. A magnetic foreign object trapping device according to any one of claims 1 to 3, wherein an oil receiving portion for receiving the oil is provided protruding from the outer surface of the mounting portion.

9. The oil receiving portion has a shape that partially protrudes in the circumferential direction of the mounting portion from the side of the mounting portion opposite to the side on which the receiving recess is provided, and has a concave portion for receiving the oil, and has an oil inlet for introducing the oil into the concave portion and an oil outlet for releasing the oil from the concave portion, as described in claim 8.

10. The magnetic foreign object trapping device according to claim 9, wherein the oil receiving portion has an expanding portion that widens the oil inlet.

11. The magnetic foreign object trapping device according to claim 8, wherein the oil receiving portion consists of a rib-shaped projection that protrudes from the side of the mounting portion opposite to the side where the receiving recess is provided.

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