Conductive particle detecting device

Abstract

The present application provides a kind of conductive granule detection device.The conductive granule detection device (1) of embodiment has: installation part, it is installed in the reducer with conductive granule in the interior;And detection part (3), it is arranged with installation part, is configured in the interior of reducer and detects conductive granule.Detection part (3) has: multiple electrode parts (13);Magnet part (12), it makes conductive granule concentrate between adjacent electrode parts (13);And detection circuit (50), it detects conductive granule based on the resistance between adjacent electrode parts (13).Electrode part (13) is formed by the material of non-magnetic and can be deformed and can be restored after deformation.

Description

Technical Field

[0001] This invention relates to a conductive particle detection device. Background Technology

[0002] For example, in mechanical actuators with built-in mechanisms such as speed reducers, wear reduction is achieved by filling the housing with lubricant. In such devices, wear and breakage can occur in mechanical parts over time. In these cases, conductive particles (metal powder) can mix into the lubricant, thereby reducing the lubricant's wear-inhibiting function on the actuator.

[0003] Therefore, in such mechanical devices, it is desirable to detect externally any amount of metal powder mixed in the lubricating fluid exceeding a specified threshold. As a countermeasure, various conductive particle detection devices have been proposed.

[0004] For example, a conductive particle detection device having an external thread portion and a detection portion arranged along the axial direction and integrated is disclosed (for example, see Japanese Patent Application Publication No. 2022-139964).

[0005] In this case, the detection unit includes a cylindrical cover, multiple electrode sections supported on the cover, and a permanent magnet and detection circuit disposed inside the cover.

[0006] Multiple electrode sections protrude radially outward from the peripheral wall of the cover and are separately disposed in the lubricating fluid. A permanent magnet uses magnetic force to concentrate conductive particles in the lubricating fluid between adjacent electrodes. A detection circuit detects the conductive particles based on the resistance between adjacent electrode sections.

[0007] Therefore, it is possible to use permanent magnets to attract conductive particles in lubricating fluid, and to electrically detect the amount of attracted conductive particles.

[0008] Furthermore, when this conductive particle detection device is installed in a mechanical actuator, the external thread of the conductive particle detection device is screwed into the internal thread formed on the housing from the outside of the housing. This allows the conductive particle detection device to be installed in the mechanical actuator with the detection part protruding into the housing. As a result, the detection part is immersed in lubricating fluid.

[0009] However, in conventional technologies, when a conductive particle detection device is mounted on a mechanically actuated device, there is a possibility that the electrode portion may deform due to contact with the housing. If the conductive particle detection device is mounted on the housing while the electrode portion remains deformed, there is a possibility that the detection accuracy of the conductive particle detection device may decrease. Summary of the Invention

[0010] The present invention provides a conductive particle detection device that can prevent a decrease in detection accuracy even when the electrode part is deformed during the installation of the conductive particle detection device.

[0011] A conductive particle detection device according to one embodiment of the present invention includes: a mounting portion mounted on an object having conductive particles inside; and a detection portion arranged with the mounting portion inside the object to detect the conductive particles. The detection portion includes: a plurality of electrode portions; a magnet portion that concentrates the conductive particles between adjacent electrode portions; and a detection circuit that detects the conductive particles based on the resistance between adjacent electrode portions. The electrode portions are formed of a non-magnetic material that is deformable and can recover its shape after deformation.

[0012] With this configuration, even if the electrode portion deforms when the conductive particle detection device is installed on the object to be installed, the electrode portion can be restored to its original shape after installation. Therefore, it is possible to prevent a decrease in the detection accuracy of the conductive particle detection device.

[0013] In the above structure, the electrode portion can be formed of a material capable of elastic deformation.

[0014] In the above structure, the mounting portion may include an externally threaded portion. Alternatively, the electrode portion may extend radially when viewed from the axial direction of the mounting portion and protrude radially outward beyond the root of the externally threaded portion.

[0015] In the above structure, the detection unit may include a cylindrical cover that supports the electrode unit. The cover may be coaxially positioned with the mounting unit and has a slit for insertion of the electrode unit. The slit may extend obliquely toward the mounting unit as it moves radially outward. The electrode unit may include: a base extending along the inner side of the cover; a folded-back portion extending obliquely from the top end of the base on the side opposite to the mounting unit, such that it is inserted into the slit; and an electrode body extending radially outward from the radially outer end of the folded-back portion.

[0016] According to the conductive particle detection device of the present invention, even if the electrode part is deformed during installation, the reduction in detection accuracy can be prevented. Attached Figure Description

[0017] Figure 1 This is a schematic structural diagram of the speed reducer in an embodiment of the present invention.

[0018] Figure 2 This is a perspective view of the conductive particle detection device according to an embodiment of the present invention.

[0019] Figure 3 It is along Figure 2 A cross-sectional view along line III-III.

[0020] Figure 4 It is along Figure 2 A cross-sectional view along line IV-IV.

[0021] Figure 5 This is an exploded perspective view of the cover portion in an embodiment of the present invention.

[0022] Figure 6 It is Figure 4 An enlarged plan view of section VI.

[0023] Figure 7 This is an explanatory diagram of the detection method for detecting conductive particles using a conductive particle detection device according to an embodiment of the present invention.

[0024] Figure 8 This is an explanatory diagram used to illustrate the behavior of the conductive particle detection device in the embodiments of the present invention when it is installed in the housing. Figure 8 The diagrams (a) to (c) show the changes in the behavior of the conductive particle detection device, respectively.

[0025] Figure 9 This is a graph showing the change in temperature of the reducer and the resistance value obtained by the resistance detection unit in the first modified example of the embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] 1. Conductive particle detection device; 2. Mounting part; 3. Detection part; 5. External thread part; 5d. Thread root; 10. Cover part; 12. Magnet part; 13. Electrode part; 21. First cover (cover part); 22. Second cover (cover part); 28. Slit; 41. Base part; 42. Fold-back part; 43. Electrode body; 50. Detection circuit; 100. Reducer (mounting object); 101. Housing part (mounting object). Detailed Implementation

[0028] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0029] <Gear Reducer>

[0030] Figure 1 This is a schematic structural diagram showing an example of a reducer 100 equipped with the conductive particle detection device 1 of the present invention.

[0031] like Figure 1 As shown, the reducer 100 is an example of a mechanical actuation device. The reducer 100 is used, for example, in the joint portion of an industrial robot used on a factory production line.

[0032] The reducer 100 includes a housing portion 101 and a reduction mechanism portion 102 housed within the housing portion 101. A conductive particle detection device 1 is mounted on the housing portion 101. The reduction mechanism portion 102 reduces the input rotation of a power source (not shown) at a predetermined reduction ratio. The housing portion 101 is filled with a non-conductive lubricant 103. The reduction mechanism portion 102 is immersed in the lubricant 103. The reduction mechanism portion 102 is lubricated using grease or an oil bath.

[0033] <Conductive Particle Detection Device>

[0034] The conductive particle detection device 1 is installed on the wall 101a of the housing portion 101. The preferred location for installing the conductive particle detection device 1 is a location where the lubricant 103 has good flowability. The conductive particle detection device 1 detects abnormalities in the reducer 100 by detecting the amount of conductive particles such as metal powder mixed into the lubricant 103.

[0035] Figure 2 This is a three-dimensional view of the conductive particle detection device 1. Figure 3 It is along Figure 2 A cross-sectional view along line III-III. Figure 4 It is along Figure 2 A cross-sectional view along line IV-IV.

[0036] like Figures 2 to 4 As shown, the conductive particle detection device 1 includes: a mounting part 2, which is mounted on the wall 101a of the housing part 101; and a detection part 3, which is arranged with the mounting part 2 and integrated with the mounting part 2.

[0037] Installation Department

[0038] The mounting part 2 includes a cylindrical base part 4 and an external thread part 5 disposed coaxially with the base part 4. The external thread part 5 is integrally formed on one axial end of the base part 4.

[0039] In the following description, the axial direction of the mounting part 2 is defined as the axial direction of the entire conductive particle detection device 1. The radial direction of the mounting part 2 is defined as the radial direction of the entire conductive particle detection device 1. The circumferential direction of the mounting part 2 is defined as the circumferential direction of the entire conductive particle detection device 1.

[0040] A pair of planar portions 4b are formed on the outer peripheral surface 4a of the base portion 4. The pair of planar portions 4b are arranged to face each other radially in the mounting portion 2. The pair of planar portions 4b are used, for example, when the conductive particle detection device 1 is mounted on the housing portion 101 (details will be described later).

[0041] A receiving recess 8 is formed within the base portion 4. A portion of the detection portion 3 is received within the receiving recess 8. An O-ring groove 6 is formed on the outer periphery of the end face 4c located on the side of the external thread portion 5 in the base portion 4. An O-ring 7 is installed in the O-ring groove 6.

[0042] The external thread 5 is screwed into the internal thread 101b formed in the wall 101a of the housing portion 101 (see reference). Figure 1 Therefore, a conductive particle detection device 1 is installed on the wall 101a of the housing 101.

[0043] The external threaded portion 5 is formed as a cylinder with a through hole 5a inside. The through hole 5a is formed along the axial direction of the external threaded portion 5 and communicates with the receiving recess 8.

[0044] A cover receiving recess 5c is formed at the top end portion 5b of the external thread portion 5, located on the side opposite to the base portion 4. The cover receiving recess 5c is coaxially disposed with the through hole 5a. The cover receiving recess 5c is circular when viewed from the axial direction. The inner diameter of the cover receiving recess 5c is larger than the inner diameter of the through hole 5a. The cover receiving recess 5c communicates with the through hole 5a.

[0045] The cover portion 10 described later is fitted into the recessed portion 5c of the cover thus constructed.

[0046] <Testing Department>

[0047] The detection part 3 is located at the top end 5b of the external thread part 5.

[0048] The detection unit 3 includes a cover 10, a support 11, four magnets 12, four electrodes 13, and a detection circuit 50.

[0049] The cover portion 10 engages with the cover receiving recess 5c of the external thread portion 5. The cover portion 10 is formed as a cylinder with a through hole 10a inside. The through hole 10a is formed along the axial direction of the cover portion 10.

[0050] The support portion 11 is inserted into the through hole 10a of the cover portion 10 and the through hole 5a of the external thread portion 5. Four magnet portions 12 are disposed between the support portion 11 and the cover portion 10 and are supported by the support portion 11. Four electrode portions 13 are supported by the cover portion 10. The detection circuit 50 is electrically connected to the electrode portions 13.

[0051] <Support section>

[0052] The support portion 11 is formed of resin, for example. The support portion 11 has a square rod-shaped support body 14 and four support legs 15. When viewed from the axial direction, the four support legs 15 are integrally formed at the four corners of the support body 14.

[0053] The support body 14 extends from the portion near the axial center of the through hole 5a of the external thread portion 5 toward the through hole 10a of the cover portion 10. Thus, the support body 14 is inserted into most of the through hole 10a of the cover portion 10. The central axis of the support body 14 coincides with the central axis of the external thread portion 5.

[0054] A support shaft portion 14b protrudes from the top end portion 14a on the side opposite to the base portion 4 in the support body 14. The support shaft portion 14b is arranged coaxially with the support body 14. The support shaft portion 14b is used to support the cover portion 10 on the support body 14 (details will be described later).

[0055] Four support legs 15 extend along the entire axial direction of the support body 14. Furthermore, the four support legs 15 extend from the support body 14 toward the base portion 4. At the end of each support leg 15 located on the base portion 4 side, an outer flange portion 15a is integrally formed, extending radially outward. The outer flange portion 15a overlaps axially with the bottom surface 8a of the receiving recess 8. Additionally, the bottom surface 8a is the inner wall surface of the receiving recess 8 located on the detection portion 3 side and facing axially. Thus, the support portion 11 is positioned at least axially.

[0056] Magnet receiving recesses 16 are formed on the four sides of the support body 14 using the support body 14 and each support leg 15. The four magnet receiving recesses 16 are formed to be relatively long along the axial direction and are arranged at equal intervals in the circumferential direction.

[0057] Each magnet receiving recess 16 is provided with a relay plate 17 for a metallic magnetic material. The relay plate 17 is formed in the shape of a plate. The magnet part 12 is disposed on the relay plate 17.

[0058] <Magnet Section>

[0059] The magnet portion 12 is formed in the shape of a long rod along the axial direction, corresponding to the shape of the magnet receiving recess 16. The magnet portion 12 is a conductive magnet. The magnet portion 12 has the properties of a magnet portion without receiving a supply of magnetic field or current from the outside. The magnet portion 12 is fixed by attaching to the relay plate 17 by magnetic force.

[0060] <Cover>

[0061] Figure 5 This is an exploded perspective view of the cover 10.

[0062] The cover 10 is formed of resin, for example. The surface of the cover 10 may, for example, be oil-repellent.

[0063] like Figures 2 to 5As shown, the cover portion 10 includes a first cover 21 and a second cover 22 arranged in an axial direction. The first cover 21 and the second cover 22 can be separated in the axial direction. Thus, the cover portion 10 is formed by dividing the first cover 21 and the second cover 22.

[0064] The first cover 21 is disposed on the mounting portion 2 side. The first cover 21 includes a first cylindrical portion 23 and four first cover legs 24. The four first cover legs 24 are formed to extend axially from the end of the first cylindrical portion 23 located on the side of the second cover 22 toward the second cover 22.

[0065] The end of the first cylindrical portion 23 located on the side of the external thread portion 5 is fitted into the cover receiving recess 5c.

[0066] The four first cover legs 24 are arranged at equal intervals in the circumferential direction. With the first cover 21 installed on the external threaded portion 5, the four first cover legs 24 are located radially outward of the magnet portion 12. The first cover legs 24 are formed in the shape of plates. For example, the first cover legs 24 are formed in the shape of plates whose thickness along the thickness direction is the same as their width along the radial direction.

[0067] The first cover leg 24 is capable of elastic deformation in the radial direction. Moreover, the first cover leg 24 uses elastic recovery deformation to press the magnet part 12 from the radially outer side to the radially inner side. As a result, the first cover leg 24 elastically presses the magnet part 12 slightly.

[0068] The inner circumferential surface of the first cylindrical portion 23 and the inner circumferential surface of the first cover leg portion 24 constitute a through hole 10a as the cover portion 10. A first spacer receiving recess 25 is formed on the inner circumferential surface of the first cover leg portion 24, in the majority of its circumferentially central portion. The first spacer receiving recess 25 is formed over the entire axial range of the first cover leg portion 24. The first spacer receiving recess 25 receives the spacer 39 (described later) and the magnet portion 12.

[0069] A limiting protrusion 26 is formed at the axial center of the first spacer receiving recess 25. The limiting protrusion 26 extends over the entire circumferential range of the first spacer receiving recess 25. With the first cover 21 installed on the external thread portion 5, the limiting protrusion 26 is located on the side closer to the external thread portion 5 than the magnet portion 12. Thus, the limiting protrusion 26 restricts the axial movement of the magnet portion 12.

[0070] A first inclined surface 27 is formed at the top end of the first cover leg 24 on the side of the second cover 22. The first inclined surface 27 is inclined in a manner that gradually moves radially inward toward the top end of the first cover leg 24. The first inclined surface 27 cooperates with the second cover 22 to form a slit 28.

[0071] The electrode section 13 is supported in a state where it is inserted into the slit 28. Details of the slit 28 and the electrode section 13 will be described below.

[0072] The second cover 22 has a second cylindrical portion 31 and four second cover legs 32. The four second cover legs 32 are formed to extend axially from the end of the second cylindrical portion 31 located on the side of the first cover 21 toward the first cover 21.

[0073] A sealing plate 33 is integrally formed at the axial center of the second cylindrical portion 31. A through hole 33a is formed in the radially central portion of the sealing plate 33, extending through the sealing plate 33 in the thickness direction (axial direction).

[0074] The support shaft portion 14b of the support portion 11 is inserted into the through hole 33a. Thus, the second cover 22 is supported by the support portion 11 (support portion body 14).

[0075] On the inner circumferential surface of the second cylindrical portion 31, a second spacer receiving recess 35 is formed at a position corresponding to the first spacer receiving recess 25 of the first cover leg portion 24.

[0076] The second spacer receiving recess 35 extends from the sealing plate 33 to the end 31a of the second cylindrical portion 31 (the end 31a of the second cylindrical portion 31 located on the side of the first cover 21). The second spacer receiving recess 35 is axially aligned with the first spacer receiving recess 25. The spacer 39, described later, is received in the second spacer receiving recess 35.

[0077] The position of the end portion 31a of the second cylindrical portion 31 corresponding to the second spacer receiving recess 35 is axially opposite to the first inclined surface 27 of the first cover leg portion 24. Furthermore, a second inclined surface 34 is formed on the portion of the end portion 31a that is axially opposite to the first inclined surface 27.

[0078] The second inclined surface 34 is inclined in a manner that gradually moves radially outward toward the first cover leg 24, corresponding to the first inclined surface 27. The second inclined surface 34 and the first inclined surface 27 are axially opposed by a predetermined gap. Therefore, a slit 28 is formed between the first inclined surface 27 and the second inclined surface 34, extending inclinedly toward the mounting portion 2 as it moves radially outward.

[0079] Four second cover legs 32 are arranged at equal intervals in the circumferential direction. The four second cover legs 32 are configured to block the space between adjacent first cover legs 24 in the circumferential direction when the second cover 22 is supported on the support portion 11. The second cover legs 32 are formed in a plate shape. For example, the second cover legs 32 are formed in a plate shape where the thickness along the thickness direction is the same as the width along the radial direction. The inner circumferential surface of the second cylindrical portion 31 and the inner circumferential surface of the second cover legs 32 constitute a through hole 10a for the cover portion 10.

[0080] <Electrode Section>

[0081] Figure 6 It is Figure 4 An enlarged plan view of section VI.

[0082] like Figure 2 , Figure 3 , Figure 4 , Figure 6 As shown, the electrode portion 13 is disposed on the outer surface 12a of the magnet portion 12, which is radially outward, with a spacer 39 between them. The spacer 39 is formed as a plate that is longer in the axial direction. The spacer 39 is housed in the first spacer housing recess 25 of the first cover 21 and the second spacer housing recess 35 of the second cover 22. The spacer 39 is formed of a conductive, non-magnetic conductor, such as brass, aluminum, or copper.

[0083] The electrode portion 13 is formed by bending a conductive, non-magnetic metal sheet such as stainless steel. Specifically, the electrode portion 13 is formed by bending the metal sheet through a process such as stamping. The thickness of the electrode portion 13 is, for example, about 0.1 mm. The electrode portion 13 is elastically deformable. The surface of the electrode portion 13 may, for example, have oil-repellent properties.

[0084] More specifically, the electrode portion 13 includes a base portion 41, a folded-back portion 42, and an electrode body 43. The electrode portion 13 is formed by integrally molding the base portion 41, the folded-back portion 42, and the electrode body 43.

[0085] The base portion 41 is disposed on the radially outer outer surface 35a of the spacer 39, and is formed to extend along the outer surface 35a and the inner peripheral surface of the first cover leg portion 24. The folded-back portion 42 is folded back in such a way that it extends radially outward from the top end portion 41a of the base portion 41 located on the side opposite to the mounting portion 2. The electrode body 43 is formed to extend radially outward from the radially outer outer end portion 42a of the folded-back portion 42.

[0086] The folded-back portion 42 is inserted into the slit 28. Thus, the electrode portion 13 is supported by the cover portion 10. The outer end portion 42a of the folded-back portion 42 is located on the outer peripheral surfaces of the first cover 21 and the second cover 22. Therefore, the electrode body 43 protrudes radially outward from the outer peripheral surface of the cover portion 10.

[0087] The electrode body 43 is configured such that its thickness direction is aligned with its axial direction. Therefore, the angle θ between the folded-back portion 42 and the electrode body 43 is an obtuse angle.

[0088] When viewed from the axial direction (refer to) Figure 3 The tip portion 43a of the electrode body 43, located radially outward, is formed to taper towards the radially outward direction. Furthermore, when viewed axially, the tip portion 43a of the electrode body 43 is larger than the root 5d of the external thread portion 5 in the mounting portion 2 (see reference). Figure 4 It protrudes radially outward.

[0089] As described above, the first cover leg 24 elastically presses slightly against the magnet portion 12 from the radially outer side toward the radially inner side. Consequently, the base portion 41 and spacer 39 of the electrode portion 13 are elastically pressed against the magnet portion 12 by the first cover leg 24. Thus, the magnet portion 12 comes into full contact with the base portion 41 and spacer 39. Therefore, the electrode portion 13 and the magnet portion 12 are in a state of mutual conductivity. Since the electrode portion 13 and spacer 39 are non-magnetic, the electrode portion 13 is in communication with the magnet portion 12 without being magnetized.

[0090] <Detection Circuit>

[0091] like Figure 3 As shown, the detection circuit 50 includes a wiring board 53 connected to the relay piece 17, and a resistance detection unit 51 and a power supply 52 connected to the relay piece 17 via the wiring board 53.

[0092] Power supply 52 applies voltage to any electrode portion 13. Resistance detection unit 51 detects the resistance value between the voltage-applied electrode portion 13 and another electrode portion 13 adjacent to it in the circumferential direction. Therefore, detection circuit 50 detects the amount of conductive particles such as metal powder mixed into the lubricant 103 of reducer 100 based on the detected change in resistance value. Thus, conductive particle detection device 1 detects abnormalities in reducer 100.

[0093] The following describes the specific abnormality detection method for the conductive particle detection device 1 to detect abnormalities in the reducer 100.

[0094] <Anomaly Detection Method for Preventing Abnormalities in Reducers Using Conductive Particle Detection Device>

[0095] Figure 7 This is an explanatory diagram of the detection method for conductive particles using the conductive particle detection device 1. Figure 7 Equivalent to Figure 3 A magnified view of a portion of the image.

[0096] First, the initial wear powder (metal powder) with a small particle size generated during the initial use of the reducer 100 (sometimes referred to as the initial drive) will be explained. The initial wear powder is a fine metal powder with a particle size of, for example, less than 10 μm (usually less than about 2 μm), which has almost no adverse effect on the operation of the reducer 100.

[0097] like Figure 1 , Figure 7As shown, the detection unit 3 is configured to protrude into the housing portion 101 of the reducer 100, and is therefore immersed in the lubricant 103. In this state, the initial wear powder is magnetically attracted by the magnet portion 12 of the conductive particle detection device 1. Consequently, the initial wear powder adheres to the outer peripheral surface of the cover portion 10, namely the outer peripheral surfaces of the first cover leg portion 24 and the second cover leg portion 32, forming a lower layer Ps. Around the adhered initial wear powder, the lubricant 103 remains as a non-conductive layer.

[0098] In the initial state of use, the lubricant 103 is non-conductive, so the resistance value detected by the resistance detection unit 51 is infinite. Furthermore, the adhesion of the initial wear powder is relatively weak. Therefore, the amount of initial wear powder accumulating between adjacent electrode portions 13 in the circumferential direction is also reduced.

[0099] Since the electrode portion 13 is a non-magnetic conductor, it will not be magnetized by the magnetic force of the magnet portion 12. Therefore, it is possible to suppress the initial wear powder from adhering to the electrode body 43 protruding from the outer peripheral surface of the cover portion 10 in the electrode portion 13.

[0100] As a result, during the initial drive of the reducer 100, phenomena such as the electrode body 43 being buried in initial wear powder can be suppressed as much as possible.

[0101] Next, the use of metal powder over time will be explained.

[0102] The metal powder used over time is metal powder that has accumulated over a certain period after the initial wear powder is generated. In other words, the metal powder used over time is metal powder such as wear powder and broken pieces (metal sheets) generated during the normal use of the reducer 100. The particle size of the metal powder used over time is, for example, as large as 10 μm or more. Therefore, the metal powder used over time is easily affected by the magnetic force of the magnet part 12, easily pushing away the non-conductive lubricant and causing the metal powder to attract each other.

[0103] As the amount of time-consuming metal powder mixed into the lubricant 103 increases, the time-consuming metal powder is magnetically attracted by the magnet portion 12. Furthermore, the time-consuming metal powder adheres to the circumferentially adjacent electrode portions 13 on the outer peripheral surface of the cover portion 10. Influenced by the magnetic force of the magnet portion 12, the time-consuming metal powder accumulates on the lower layer Ps attached to the outer peripheral surface of the cover portion 10. Thus, the time-consuming metal powder forms an upper layer Pn on the lower layer Ps.

[0104] If the amount of metal powder deposited on the outer peripheral surface of the cover 10 reaches a predetermined amount or more over time, the resistance value detected by the resistance detection unit 51 will be below a predetermined value. When the detected resistance value is below the predetermined value, the detection circuit 50 determines that the reducer 100 is abnormal. As a result, the abnormality of the reducer 100 is detected by the conductive particle detection device 1.

[0105] In addition, for example, when the output speed of the reducer 100 is very slow, during the period from the generation of initial wear powder to the generation of metal powder used over time, a large amount of metal powder with a particle size larger than the initial wear powder but almost no electrical conductivity may be generated.

[0106] In such a situation, there is a possibility that the electrode body 43 may be buried by the metal powder or initial wear powder. If the electrode body 43 is buried by metal powder that has almost no adverse effect on the operation of the reducer 100, it is impossible to use the detection circuit 50 to detect the adhesion of metal powder over time with high precision.

[0107] In this respect, in the conductive particle detection device 1 of this embodiment, the top end 43a of the electrode body 43 protrudes radially outward from the root 5d of the external thread portion 5 in the mounting portion 2 when viewed from the axial direction. This configuration prevents the electrode body 43 from being buried by metal powder that has virtually no adverse effect on the operation of the reducer 100. Furthermore, it prevents a decrease in the detection accuracy of the conductive particle detection device 1.

[0108] The following describes the behavior of such a conductive particle detection device 1 when installed in the reducer 100.

[0109] <Regarding the installation behavior of the conductive particle detection device>

[0110] Figure 8 This is an explanatory diagram illustrating the behavior of the conductive particle detection device 1 when it is installed in the housing 101 of the reducer 100. Figure 8 (a) to (c) respectively represent the changes in the behavior of the conductive particle detection device 1.

[0111] like Figure 8 As shown in (a), when the conductive particle detection device 1 is installed on the housing portion 101, firstly, the detection portion 3 of the conductive particle detection device 1 is oriented toward the internal thread portion 101b formed on the wall 101a of the housing portion 101.

[0112] Next, as Figure 8 As shown in (b), the detection part 3 is inserted into the internal thread part 101b (refer to...). Figure 8 (See arrow Y1 in (b)). At this time, the top end 43a of the electrode body 43 protrudes radially outward from the root 5d of the external thread portion 5 in the mounting portion 2 when viewed from the axial direction. Therefore, the electrode body 43 contacts the internal thread portion 101b.

[0113] Therefore, if the detection part 3 is gradually inserted into the internal thread 101b in this manner, the electrode body 43 will elastically deform by tilting towards the mounting part 2 (see reference). Figure 8 Arrow Y2 in (b) should also be referenced.Figure 6 The angle θ between the folded-back portion 42 and the electrode body 43 is an obtuse angle. Therefore, the electrode body 43 smoothly and elastically deforms by tilting towards the mounting portion 2. No force is applied to the electrode body 43 that would bend it in an abnormal direction.

[0114] Then, if the detection part 3 is inserted further, the external threaded part 5 of the mounting part 2 abuts against the internal threaded part 101b of the wall 101a. Therefore, the operation of screwing the external threaded part 5 into the internal threaded part 101b is performed. At this time, the mounting part 2 can be rotated by locking a tool on a pair of flat surfaces 4b formed on the base part 4 of the mounting part 2. Thus, the external threaded part 5 can be smoothly fastened to the internal threaded part 101b.

[0115] Then, as Figure 8 As shown in (c), when the external threaded portion 5 is fully tightened to the internal threaded portion 101b, the end face 4c of the base portion 4 abuts against the wall 101a. At this time, the O-ring 7 provided on the end face 4c ensures the sealing between the wall 101a of the housing portion 101 and the conductive particle detection device 1.

[0116] The portion of the detection unit 3 where the electrode body 43 is located becomes a state where it completely protrudes into the interior of the wall 101a through the internal thread portion 101b. Therefore, an elastic restoring force acts on the electrode body 43, restoring it to its state before it was installed into the housing portion 101. Thus, the top portion 43a of the electrode body 43 can be restored to a state where, when viewed axially, it protrudes radially outward from the root 5d of the external thread portion 5 in the mounting portion 2.

[0117] Thus, the installation of the conductive particle detection device 1 into the housing 101 is completed.

[0118] Thus, in the conductive particle detection device 1 of this embodiment, the electrode portion 13 is formed of a non-magnetic material that is deformable and can recover after deformation. Therefore, even if the electrode portion 13 deforms when the conductive particle detection device 1 is installed on the housing portion 101 of the reducer 100, the electrode portion 13 can be recovered after installation. As a result, it is possible to prevent a decrease in the detection accuracy of the conductive particle detection device 1.

[0119] The electrode portion 13 is formed of a material capable of elastic deformation. Therefore, the electrode portion 13 can be easily manufactured. Moreover, plastic deformation of the electrode portion 13 can be prevented. Thus, even if the electrode portion 13 is deformed, it can be reliably restored after installation.

[0120] The electrode portion 13 extends radially when viewed from the axial direction and protrudes radially outward beyond the root 5d of the external thread portion 5. This configuration allows the electrode portion 13 to be extended as much as possible. Therefore, for example, it is possible to prevent the electrode body 43 of the electrode portion 13 from being buried by initial wear powder that does not require detection. Thus, it is possible to prevent a decrease in the detection accuracy of the conductive particle detection device 1.

[0121] A slit 28 for supporting the electrode portion 13 is formed in the cover portion 10. The slit 28 extends obliquely toward the mounting portion 2 as it moves radially outward. That is, the slit 28 extends obliquely toward the side opposite to the insertion direction in which the conductive particle detection device 1 is inserted into the housing portion 101.

[0122] The electrode portion 13 is formed by bending a sheet metal plate (metal sheet) through processes such as stamping, and includes a base portion 41, a folded-back portion 42, and an electrode body 43.

[0123] The fold-back portion 42 extends radially outward from the top end portion 41a of the base portion 41 on the side opposite to the mounting portion 2, in a manner that allows insertion into the slit 28. Therefore, the angle θ between the fold-back portion 42 and the electrode body 43 is an obtuse angle. Consequently, when the external thread portion 5 of the conductive particle detection device 1 is fastened to the internal thread portion 101b of the housing portion 101, the electrode body 43 of the electrode portion 13 can smoothly and elastically deform.

[0124] As a result, the electrode portion 13 will not undergo abnormal elastic deformation, thus preventing damage to the electrode portion 13. This prevents a decrease in the detection accuracy of the conductive particle detection device 1. Furthermore, it improves the installability of the conductive particle detection device 1.

[0125] [Example 1]

[0126] In the above embodiment, the following situation was described: when the amount of metal powder accumulated in the reducer 100 over time reaches a predetermined amount or more, and the resistance value detected by the resistance detection unit 51 falls below a predetermined value, the detection circuit 50 determines that the reducer 100 is abnormal. However, it is not limited to this; in addition to the determination based on the resistance value detected by the resistance detection unit 51, the detection results of various sensors can also be used to determine the abnormality of the reducer 100.

[0127] Various sensors are used, including temperature sensors that detect the temperature of the reducer 100. The temperature sensor can be installed at any location on the reducer 100, or in the conductive particle detection device 1. For example, the temperature sensor is installed in the detection circuit 50 of the conductive particle detection device 1.

[0128] Figure 9It is a graph showing the relationship between the temperature change of the reducer 100 and the change in resistance value detected by the resistance detection unit 51 and the operating time of the reducer 100. Figure 9 The vertical axis shown represents the temperature of the reducer 100 and the resistance value detected by the resistance detection unit 51. Figure 9 The horizontal axis shown represents the operating time of the reducer 100.

[0129] Also consider the following situation: under the use of the conductive particle detection device 1, metal powder is unlikely to accumulate on the outer peripheral surface of the cover 10 over time. In such a case, if... Figure 9 As shown, there are cases where the resistance value detected by the resistance detection unit 51 does not completely drop below the specified value. Therefore, there are cases where the detection circuit 50 does not determine that the reducer 100 is malfunctioning.

[0130] However, if the resistance value decreases several times, it can be considered a sign that the reducer 100 is malfunctioning. Hereinafter, this situation will be referred to as a sign of malfunction in the reducer 100. Despite the presence of such signs of malfunction in the reducer 100, it is possible to determine that the reducer 100 is malfunctioning at a later time than appropriate.

[0131] Therefore, a temperature sensor is installed in the conductive particle detection device 1 to monitor the detection results of the temperature sensor. Furthermore, if there are signs of an abnormality in the reducer 100 and the temperature sensor determines that the temperature of the reducer 100 is starting to rise, an abnormality in the reducer 100 is determined. The reason for this determination is that, for example, the increase in the temperature of the reducer 100 leads to a decrease in the viscosity of the lubricant 103, resulting in a thinner oil film and thus a deterioration in the lubrication condition.

[0132] Therefore, according to the first modified example, by combining temperature sensors, it is possible to determine the abnormality of the reducer 100 with high accuracy.

[0133] Furthermore, in the first modification, the case where a temperature sensor is added to the anomaly detection of the reducer 100 was described. However, this is not the only limitation; for example, an acceleration sensor may also be added. The vibration of the reducer 100 may also be detected using an acceleration sensor, and the detection result may be used for anomaly detection of the reducer 100.

[0134] [Second variation]

[0135] In the first modification, the case where a temperature sensor is provided in the detection circuit 50 of the conductive particle detection device 1 was described, for example. However, it is not limited to this; the temperature sensor may also be mounted on the wiring board 53. With this configuration, the internal temperature of the reducer 100, such as the temperature of the lubricant 103, can be measured. Therefore, the accuracy of temperature measurement of the reducer 100 can be improved.

[0136] When the temperature sensor is mounted on the wiring substrate 53, polyimide, for example, can also be glued over it from above. This configuration protects the temperature sensor.

[0137] When measuring the temperature of the lubricant 103 in the reducer 100 as in the second modified example, a temperature of around 60° to 70° indicates a malfunction in the reducer 100. In contrast, when a temperature sensor is installed in the wall 101a of the housing portion 101 in the reducer 100, a temperature of around 60° indicates a malfunction in the reducer 100.

[0138] [3rd variation]

[0139] In the above embodiment, the case where the cover portion 10 cannot rotate around the support shaft portion 14b has been described. However, it is not limited to this, and the portion of the cover portion 10 located around the electrode portion 13 can also be configured to rotate around the support shaft portion 14b. For example, the second cylindrical portion 31 and the second cover leg portion 32 of the second cover 22 can be separated, and the second cylindrical portion 31 side can be configured to rotate relative to the first cover 21 around the support shaft portion 14b.

[0140] Furthermore, it can be assumed that the flow of lubricant 103 filled in the housing portion 101 of the reducer 100 is less likely to become turbulent overall, and may become unidirectional depending on the specific location. In such cases, it can be assumed that it is difficult to uniformly accumulate metal powder over time in the conductive particle detection device 1 at that specific location, and the metal powder accumulates in a biased manner in a localized area of ​​the cover portion 10. In this case, the detection accuracy of the conductive particle detection device 1 deteriorates.

[0141] Therefore, in the third modification, the portion of the cover 10 located around the electrode portion 13 is configured to rotate around the support shaft portion 14b. With this configuration, even if the flow of the lubricant 103 within the housing portion 101 is in a specific direction, the metal powder can be uniformly deposited around the entire periphery of the cover 10 over time. Thus, the detection accuracy of the conductive particle detection device 1 can be improved regardless of the flow of the lubricant 103 within the housing portion 101.

[0142] [Other variations]

[0143] This invention is not limited to the embodiments described above, but includes embodiments obtained by making various modifications to the embodiments described above without departing from the spirit of this invention.

[0144] For example, in the above embodiment, the case where the cover 10 is divided into a first cover 21 and a second cover 22 has been described. However, it is not limited to this, and the shape and structure of the cover 10 can be arbitrarily determined. The cover 10 may also be absent. As long as the electrode portion 13 protrudes radially outward from the magnet portion 12, it is acceptable. The magnet portion 12 is acceptable as long as it can concentrate the conductive particles between adjacent electrode portions 13. For example, even when the cover 10 is provided, the electrode portion 13 may be provided on the outer peripheral surface of the cover 10.

[0145] In the above embodiments, the case where the electrode portion 13 and the magnet portion 12 are independently provided has been described. However, it is not limited to this, and the electrode portion 13 and the magnet portion 12 may also be integrally formed. For example, the electrode portion 13 and the magnet portion 12 may be formed in two colors, and only the portion corresponding to the magnet portion 12 may be magnetized.

[0146] In the above embodiment, the conductive particle detection device 1 was described as having four first cover legs 24, four second cover legs 32, four magnet parts 12, and four electrode parts 13. However, it is not limited to this, as long as it has at least two of each. Thus, the resistance between two electrode parts 13 can be detected by the resistance detection unit 51.

[0147] In the above embodiment, the case where a detection circuit 50 is provided as a detection unit that detects the resistance between the two electrode sections 13 by means of the magnet section 12 and determines an anomaly based on the detection result has been described. The case where the detection circuit 50 determines the reducer 100 to be abnormal when the resistance value detected by the resistance detection section 51 is below a predetermined value has been described. However, it is not limited to this; the detection circuit 50 may also be configured to activate a signal output (e.g., turn on a lamp) only when the resistance between the electrode sections 13 exceeds a predetermined value. Furthermore, it is also possible to determine that the reducer 100 is abnormal simply when the detection circuit 50 activates and outputs a signal. The resistance value detection result can be output in various forms.

[0148] In the above embodiments, the case where the conductive particles are metal powder has been described. However, it is not limited to this, and various conductive particles other than metals can be cited as conductive particles. For example, as metal powder, magnetic materials of iron and materials that are electrically conductive can be cited, but even conductive resins can be detected using the conductive particle detection device 1.

[0149] In the above embodiments, the reducer 100 was described as an example of a mechanical actuation device. The reduction mechanism 102 was described as an example of an actuation mechanism. Furthermore, the case where the conductive particle detection device 1 is provided in the reducer 100 was described. However, it is not limited to this, and the conductive particle detection device 1 can be used in mechanical actuation devices such as gear devices that have various actuation mechanisms.

[0150] In the above embodiment, the case where the electrode portion 13 is formed of a material capable of elastic deformation has been described. However, it is not limited to this; the electrode portion 13 may also be non-elastically deformable. The electrode portion 13 can be formed of any non-magnetic material that is deformable and can recover its shape after deformation. For example, the electrode portion 13 may also be formed of a shape memory alloy. Shape memory alloys can recover their shape at a specified temperature or after a specified time. In addition, the electrode portion 13 can also be formed of a material that can recover its shape under specified conditions.

[0151] In the embodiments disclosed in this specification, for a structure composed of multiple objects, the multiple objects can be integrated into one, or conversely, a structure composed of a single object can be divided into multiple objects. Whether or not they are integrated, as long as the configuration achieves the purpose of the invention, it is acceptable.

Claims

1. A conductive particle detection device, wherein, This conductive particle detection device has the following features: The mounting section is installed on an object containing conductive particles; and A detection unit, arranged alongside the mounting unit, is disposed inside the object to be mounted and detects the conductive particles. The detection unit includes: Multiple electrode sections; A magnet portion that concentrates the conductive particles between adjacent electrode portions; and The detection circuit detects the conductive particles based on the resistance between adjacent electrode portions. The electrode portion is formed of a non-magnetic material that is deformable and can recover after deformation.

2. The conductive particle detection device according to claim 1, wherein, The electrode portion is formed of a material capable of elastic deformation.

3. The conductive particle detection device according to claim 1 or 2, wherein, The mounting part includes an external threaded part. The electrode portion extends radially when viewed from the axial direction of the mounting portion and protrudes radially outward from the root of the external thread portion.

4. The conductive particle detection device according to claim 3, wherein, The detection unit includes a cylindrical cover that supports the electrode unit. The cover and the mounting portion are coaxially arranged, and the cover has a slit for inserting the electrode portion. The slit extends at an angle toward the mounting portion as it moves radially outward. The electrode portion includes: A base portion that extends along the inner side surface of the cover portion; A folded-back portion, which extends obliquely from the top portion of the base portion on the side opposite to the mounting portion, in a manner that allows it to be inserted into the slit; and The electrode body extends radially outward from the radially outer end of the folded-back portion.

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