Determination device

Abstract

A probe is provided with a probe body that comes into contact with a measurement target surface of a bearing and detects an impedance of the bearing, and a housing that includes a hole in which the probe body is accommodated and has a substantially cylindrical shape. A switch is attachable to and detachable from the housing.

Description

Technical Field

[0001] The present invention relates to a determination device.

Background Art

[0002] For example, rolling bearings for paper-making machines, wind power generation equipment, mining and construction equipment, and railway vehicles are used under severe lubrication conditions where heavy loads and foreign substances or water penetrate, so peeling of the bearing raceway surface becomes a problem. When peeling occurs in a rolling bearing, it can not only cause significant damage to products and equipment, but also affect the manufacturing delivery date and schedule. To prevent sudden peeling, the rolling bearing may be disassembled and cleaned regularly, and an appearance inspection of the raceway surface may be performed. However, predicting the remaining life of the bearing (estimating the period until peeling occurs) by appearance inspection depends on the experience and skills of the operator, and quantitative prediction has been difficult.

[0003] On the other hand, Patent Document 1 discloses an eddy current flaw detector that detects defects generated in a conductive test object such as a metal material using electromagnetic induction. In the eddy current flaw detector of Patent Document 1, a probe is scanned while maintaining a certain angle and distance with respect to the test object. The angle and distance of the probe with respect to the test object are maintained by the probe operation unit described in FIGS. 2 to 4 of Patent Document 1. This probe operation unit is composed of various parts such as a gripping part, a shaft, a collar, a bolt, a rotary lock nut, a roller, a momentary switch, and an encoder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, in Patent Document 1, the probe is made larger because the probe operating section, including a momentary switch, is integrated into the probe. Therefore, when inserting the probe into a gap in the object to be measured, a probe with an integrated switch and other components, as in Patent Document 1, may not be applicable. On the other hand, there may be situations where it is easier to measure by attaching a switch to the probe and operating the switch with the hand holding the probe.

[0006] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a determination device that allows the switch to be attached to and detached from the probe depending on the situation and has excellent operability. [Means for solving the problem]

[0007] Therefore, the above objective of the present invention is achieved by the configuration described in [1] below. [1] A probe that induces eddy currents in a bearing by applying an alternating magnetic field and detects the impedance of the bearing, A switch that transmits a measurement control signal to switch the start and end of acquiring the impedance measurement signal detected by the probe, Based on the impedance of the bearing, a fatigue determination unit for determining the fatigue degree or remaining life of the bearing is provided. A determination device comprising, The fatigue determination unit is, A map storage unit that stores a determination map including the relationship between the impedance characteristics of the bearing and the fatigue degree or remaining life of the bearing, A measurement switching unit that switches between a measurement execution state and a measurement non-execution state based on the state of the measurement control signal, In the measurement execution state, a data holding unit holds the measurement signal, An impedance characteristic calculation unit calculates the impedance characteristics of the bearing based on the held measurement signal, A determination unit that determines the fatigue level or remaining life of the bearing based on the impedance characteristics of the bearing and the determination map, Equipped with, The aforementioned probe A probe body that contacts the surface of the bearing to be measured and detects the impedance of the bearing, A housing that is roughly cylindrical and has a hole inside for housing the probe body, Equipped with, The switch is detachable from the housing. Judgment device. [Effects of the Invention]

[0008] According to the determination device of the present invention, the switch can be attached to and detached from the probe depending on the situation, resulting in excellent operability. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of a device for determining the fatigue level or remaining life of a bearing. [Figure 2] Figure 2 is a schematic diagram of the fatigue determination unit. [Figure 3] Figure 3 is a schematic diagram showing the measurement of the impedance of the raceway surface 61 of the outer ring 60 of a rolling bearing using a probe 10. [Figure 4] Figure 4 is a perspective view of the probe. [Figure 5] Figure 5 is a cross-sectional view of the probe. [Figure 6] Figure 6 is a cross-sectional view showing the probe in contact with the raceway surface of the outer ring perpendicularly. [Figure 7] Figure 7 is a view in the direction of arrow VII in Figure 6. [Figure 8] Figure 8 is a cross-sectional view taken along the lines of arrows VIII1-VIII1 or VIII2-VIII2 in Figure 6. [Figure 9] Figure 9 is a magnified view of the probe in Figure 7. [Figure 10] Figure 10 is a cross-sectional view showing the probe in contact with the inner ring raceway surface perpendicularly. [Figure 11] Figure 11 is a view of Figure 10 as seen in the direction of arrow XI. [Figure 12] Figure 12 is a cross-sectional view taken along the arrow XII-XII in Figure 11. [Figure 13] Figure 13 is a cross-sectional view taken along the arrow XIII-XIII in Figure 11. [Figure 14] Figure 14 is an enlarged view of the probe in Figure 11. [Figure 15] Figure 15 is a partially enlarged view of Figure 10. [Figure 16] Figure 16 is a view showing a state where a switch is attached to the probe. [Figure 17] Figure 17 is a view showing a state where the switch is moved from the state in Figure 16 to the tip side of the probe. [Figure 18] Figure 18 is a perspective view of the switch as seen from the front side. [Figure 19] Figure 19 is a perspective view of the switch as seen from the back side.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, a determination device for determining the fatigue degree or remaining life of a bearing according to each embodiment of the present invention will be described in detail based on the drawings.

[0011] Figure 1 is a schematic configuration diagram of a determination device for determining the fatigue degree or remaining life of a bearing. As shown in Figure 1, the determination device 1 includes a probe 10 that induces eddy currents in the bearing by applying an alternating magnetic field and detects the impedance of the bearing, a switch 30 that transmits a measurement control signal S2 for switching the start and end of the capture of the measurement signal S1 of the impedance detected by the probe 10, an input unit 40 that captures the measurement signal S1 and the measurement control signal S2, and a fatigue determination unit 50 that determines the fatigue degree or remaining life of the bearing based on the impedance of the bearing.

[0012] The probe 10 has a coil (not shown) built inside. By passing an excitation current through the coil in the probe 10 and applying an alternating magnetic field to the bearing to be measured (for example, the outer ring, inner ring, or rolling elements of a rolling bearing), eddy currents are induced. By detecting the impedance generated in the coil by these eddy currents, the metal structure (for example, the amount of retained austenite) can be measured non-destructively. Examples of surfaces to be measured in a bearing include the raceway surface, outer surface, and axial end faces of the outer ring, the raceway surface, inner surface, and axial end faces of the inner ring, the circumferential surface of the rolling elements, and the circumferential surface of the cage.

[0013] When the probe 10 is in contact with the surface of the bearing to be measured, the bearing impedance measurement signal S1 is always transmitted to the fatigue determination unit 50 via the input unit 40. However, as will be described later, the fatigue determination unit 50 does not always acquire the measurement signal S1, and the acquisition of the measurement signal S1 is switched on or off based on the state of the measurement control signal S2 transmitted by the switch 30.

[0014] Switch 30 is a component that can be pressed by the user. For example, when switch 30 is pressed (ON state), a measurement control signal S2 that switches the start and end of acquiring the measurement signal S1 is sent to the input unit 40, and when switch 30 is not pressed (OFF state), the measurement control signal S2 is not sent to the input unit 40. For example, when the measurement control signal S2 is sent to the input unit 40, the measurement signal S1 is acquired by the fatigue determination unit 50 and measurement is performed, resulting in a measurement execution state, and when the measurement control signal S2 is not sent to the input unit 40, the measurement signal S1 is not acquired by the fatigue determination unit 50 and measurement is not performed, resulting in a measurement non-execution state.

[0015] The input unit 40 is connected to the probe 10 via a cable 25 (see Figure 3) described later and includes an A / D converter (not shown) that receives a measurement signal S1 of the bearing impedance detected by the probe 10, and a digital input / output unit (not shown) that is connected to a switch 30 and receives a measurement control signal S2 transmitted by the switch 30. The measurement signal S1 and the measurement control signal S2 are transmitted to the fatigue determination unit 50 via the input unit 40.

[0016] Figure 2 is a schematic diagram of the fatigue determination unit. As shown in Figure 2, the fatigue determination unit 50 includes a map storage unit 51 that stores a determination map including the relationship between the impedance characteristics (resistance component and reactance component) of the bearing and the fatigue level or remaining life of the bearing; a measurement switching unit 53 that switches between a measurement execution state and a measurement non-execution state based on the state of the measurement control signal S2; a data storage unit 55 that holds the measurement signal S1 in the measurement execution state; an impedance characteristic calculation unit 57 that calculates the impedance characteristics (resistance component and reactance component) of the bearing based on the held measurement signal S1; a determination unit 59 that determines the fatigue level or remaining life of the bearing based on the impedance characteristics (resistance component and reactance component) of the bearing and the determination map; and a display unit 58 that displays the determination result.

[0017] The fatigue determination unit 50 may include, for example, a computer including a processor and peripheral components such as a memory device. The processor may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The memory device may include any of semiconductor memory devices, magnetic memory devices, and optical memory devices. The memory device may include registers, cache memory, and memory such as ROM (Read Only Memory) and RAM (Random Access Memory) used as main memory. The fatigue determination unit 50 may be composed of dedicated hardware for executing each information processing. For example, the fatigue determination unit 50 may include functional logic circuits set in a general-purpose semiconductor integrated circuit. For example, the fatigue determination unit 50 may have a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0018] The fatigue determination unit 50 determines the remaining life of the bearing by referring to the correlation between the impedance characteristics measured by the probe 10 and the determination map stored in the map storage unit 51, and displays it on a display unit 58 such as a display.

[0019] Figure 3 is a schematic diagram showing the measurement of the impedance of the raceway surface 61 of the outer ring 60 of a rolling bearing by the probe 10. As shown in Figure 3, the probe 10 contacts the raceway surface 61 and applies an alternating magnetic field to induce eddy currents in the raceway surface 61, thereby detecting the impedance of the raceway surface 61. The detected impedance measurement signal S1 is transmitted to the input unit 40 via the cable 25. When the surface to be measured is the raceway surface 61 of the outer ring 60, the map storage unit 51 of the fatigue determination unit 50 has previously stored a determination map that includes the relationship between the resistance component and reactance component, which are the impedance characteristics of the raceway surface 61 of the outer ring 60, and the fatigue degree or remaining life of the outer ring 60. Therefore, by measuring the impedance characteristics of the raceway surface 61 of the outer ring 60, the fatigue degree or remaining life of the outer ring 60 can be determined based on the determination map.

[0020] The measurement switching unit 53 switches between a measurement execution state, in which the measurement signal S1 is received by the fatigue determination unit 50 and measurement is performed, and a measurement non-execution state, in which the measurement signal S1 is not received by the fatigue determination unit 50 and measurement is not performed, based on the state of the measurement control signal S2. For example, the measurement switching unit 53 is in the measurement execution state when the measurement control signal S2 is transmitted from the switch 30 to the input unit 40, and in the measurement non-execution state when the measurement control signal S2 is not transmitted from the switch 30 to the input unit 40. Therefore, the user confirms that the probe 10 is in contact with the raceway surface 61 of the outer ring 60 in the correct orientation, and then presses the switch 30 to transition the determination device 1 to the measurement execution state.

[0021] The data holding unit 55 holds the measurement signal S1 of the impedance of the raceway surface 61 of the outer ring 60 when measurement is being performed.

[0022] The impedance characteristic calculation unit 57 calculates the resistance and reactance components of the impedance of the raceway surface 61 of the outer ring 60 based on the measurement signal S1 held in the data holding unit 55.

[0023] The determination unit 59 determines the fatigue level or remaining life of the outer ring 60 based on the resistance and reactance components of the impedance of the raceway surface 61 of the outer ring 60 calculated by the impedance characteristic calculation unit 57, and the determination map stored in the map storage unit 51. The determined fatigue level or remaining life of the outer ring 60 is displayed in the display unit 58.

[0024] The bearing fatigue level or remaining life is determined by the determination device 1 having the configuration described above. However, in order to accurately measure the impedance of the bearing, it is necessary to make stable and correct contact of the probe 10 with the surface to be measured. The correct position of the probe 10 is, for example, a position in which the probe 10 is perpendicular to the surface to be measured. The configuration of the probe 10, which was adopted to make stable and correct contact of the probe 10 with the bearing during measurement, will be described in detail below.

[0025] Figure 4 is a perspective view of the probe. Figure 5 is a cross-sectional view of the probe. As shown in Figures 4 and 5, the probe 10 comprises a substantially cylindrical probe body 11 that contacts the surface of the bearing to be measured to detect the impedance of the bearing, a housing 13 having a sliding hole 14 extending axially inside the housing 13, the housing 13 which houses the probe body 11 positioned in the sliding hole 14 so as to be slidable in the axial direction, a butt portion 15 provided at the tip of the housing 13 and which can abut against the surface of the bearing to be measured, and a coil spring 17 positioned in the sliding hole 14 of the housing 13 as a biasing spring that biases the probe body 11 axially relative to the housing 13.

[0026] The housing 13 is an elongated, roughly cylindrical shape extending in the axial direction (the longitudinal direction of the housing 13; the vertical direction in Figure 5). It is formed by connecting and integrating a roughly cylindrical base portion 13a and a roughly rectangular parallelepiped tip portion 13b, which are provided coaxially with each other, in the axial direction. The outer circumferential surface 13f of the base portion 13a is a cylindrical surface, and the tip portion 13b has four planar outer circumferential surfaces 13d. The housing 13 is made of resin to suppress any influence on impedance measurement. The sliding hole 14 extends axially through the base portion 13a and the tip portion 13b of the housing 13. Since the sliding hole 14 has the same diameter throughout its entire axial range, the inner diameter of the base portion 13a and the inner diameter of the tip portion 13b are the same. On the other hand, the outer diameter of the tip portion 13b is larger than the outer diameter of the base portion 13a, and therefore, a step portion 13c perpendicular to the axial direction is formed at the connection between the tip portion 13b and the base portion 13a. The user can, for example, grasp the base portion 13a of the housing 13 and abut the probe 10 against the surface to be measured. The user may also grasp the tip portion 13b of the housing 13.

[0027] The sliding hole 14 includes a tip opening 14a formed at the tip of the housing 13 (lower part in Figure 5) and a base opening 14b formed at the base of the housing 13 (upper part in Figure 5). As will be described later, the probe body 11 is biased toward the tip of the probe 10 by a coil spring 17, and this biasing force allows the probe body 11 to protrude outward from the tip opening 14a of the sliding hole 14. A cover portion 16 having a through hole 16a in its center is fitted into the base opening 14b of the sliding hole 14. A cable 25 connected to the probe body 11 is pulled out to the outside from the through hole 16a of the cover portion 16.

[0028] An elongated hole 13e is formed in one of the four outer circumferential surfaces 13d of the tip portion 13b of the housing 13, extending radially through that outer circumferential surface 13d. The elongated hole 13e is an elongated hole whose axial dimension is longer than its dimensions in two directions perpendicular to the axial direction. A pair of pins 24, 24, fixed to the holder portion 22 of the probe body 11 (described later), are positioned in this elongated hole 13e. When the probe body 11 slides in the axial direction, the pair of pins 24, 24 slide within the elongated hole 13e. The pair of pins 24, 24 then contact both axial ends (upper and lower ends in Figure 5) of the elongated hole 13e, restricting the sliding and limiting the axial movement distance of the probe body 11.

[0029] The probe body 11 comprises a probe section 21 and a holder section 22 that houses the probe section 21 and is slidable within a sliding hole 14 of the housing 13, as separate components. By separating the probe section 21 and the holder section 22 in this way, if either one is damaged, it can be replaced independently, thus reducing maintenance costs. The probe section 21 and the holder section 22 are made of resin to minimize any impact on impedance measurement.

[0030] The probe section 21 is roughly cylindrical in shape, and a coil (not shown) is embedded inside. A cable 25 for extracting the measurement signal S1 is connected to the base end (upper side in Figure 5) of the probe section 21. The cable 25 extends through the sliding hole 14 and is pulled out to the outside through a through hole 16a in the cover section 16 installed in the base opening 14b. The pulled-out cable 25 is connected to the input section 40 (see Figure 1).

[0031] The holder portion 22 is substantially cylindrical in shape and covers the probe portion 21 from the outer circumference. A pair of female screw holes 22a, 22a are formed in a part of the holder portion 22, spaced apart from each other in the axial direction, and pins 24 are screwed into each of these female screw holes 22a, 22a. The pair of pins 24, 24 fix the probe portion 21 and the holder portion 22. Therefore, when the holder portion 22 slides against the sliding hole 14, the probe portion 21 also slides integrally with it. The pair of pins 24, 24 protrude outward from the pair of female screw holes 22a, 22a, and these pins 24, 24 contact both axial ends of the elongated hole 13e, restricting sliding, thus limiting the axial movement distance of the probe body 11.

[0032] The probe body 11, consisting of a probe portion 21 and a holder portion 22, is positioned on the tip side of the sliding hole 14. On the other hand, a coil spring 17 is positioned on the base side of the sliding hole 14. The coil spring 17 extends axially so as to contact the lid portion 16 fixed to the housing 13 and the probe body 11. As a result, the probe body 11 is biased toward the tip side relative to the housing 13 by the coil spring 17.

[0033] In this embodiment, the coil spring 17 abuts against the holder portion 22 located on the outer circumference of the probe body 11. Therefore, by setting the outer diameter of the coil spring 17 to be approximately equal to the inner diameter of the sliding hole 14, the coil spring 17 can be guided by the sliding hole 14, thereby suppressing buckling of the coil spring 17 and stabilizing the biasing force.

[0034] Furthermore, a gap exists on the inner diameter side of the coil spring 17, and the cable 25 of the probe body 11 extends through this gap. Because the cable 25 is positioned in the dead space on the inner diameter side of the coil spring 17 in this way, it contributes to miniaturizing the probe 10.

[0035] Figure 6 is a cross-sectional view showing the probe in contact with the raceway surface of the outer ring perpendicularly. Figure 7 is a view in the direction of arrow VII in Figure 6. Figure 8 is a cross-sectional view taken along the lines of arrows VIII1-VIII1 or VIII2-VIII2 in Figure 6. Figure 9 is an enlarged view of the probe in Figure 7.

[0036] As shown in Figures 4 to 9, the tip 13b of the housing 13, which is roughly rectangular in shape, is provided with abutment portion 15 that can abut against the raceway surface 61 of the outer ring 60, which is the surface to be measured. The raceway surface 61 of the outer ring 60 used in the description of the embodiment is a concave spherical surface. The shape of the raceway surface 61 is arbitrary and may be cylindrical, for example. In particular, as shown in Figures 7 and 9, the shape of the abutment portion 15 when viewed from the axial direction is preferably rectangular, and in the illustrated example, it is square.

[0037] The abutment portion 15 has four projections 26 that protrude in the axial direction and are all the same shape. As shown in Figure 9, the projections 26 are approximately rectangular parallelepipeds, and the shape of the tip surface 26a of each projection 26 is rectangular. The four projections 26 are positioned at the vertices of the rectangle of the abutment portion 15. Furthermore, viewed from the axial direction, each of the four projections 26 is located at the vertex of a rectangle R centered on the central axis O1 of the probe body 11. In Figure 9, rectangle R is a square indicated by a dashed line, and it is formed by connecting the centers of the tip surfaces 26a of the four projections 26. Therefore, the four projections 26 are The rectangles R are positioned at equidistant locations from the central axis O1 and are also arranged at equal intervals in the circumferential direction relative to the central axis O1. Note that the rectangle R does not necessarily have to be a square; for example, it may be a rectangle. Furthermore, it is preferable that the rectangle R is similar in shape to the rectangle of the abutment portion 15.

[0038] As shown in Figures 6 to 9, during measurement, it is necessary to maintain the correct orientation in which the probe 10 is perpendicular to the raceway surface 61 of the outer ring 60. Therefore, the user ensures that all four protrusions 26 of the abutment portion 15 are in contact with the raceway surface 61 of the outer ring 60.

[0039] The four protrusions 26 contact the concave spherical raceway surface 61 at their outermost corners 26b, which are furthest from the central axis O1 of the probe body 11. By bringing the outer corners 26b of each of the four protrusions 26 into contact with the raceway surface 61 in this way, the probe body 11 can be kept perpendicular to the raceway surface 61, and stable measurement results can be obtained.

[0040] When all four outer corners 26b of the four protrusions 26 come into contact with the raceway surface 61, the user can perceive that the wobbling of the probe 10 being held is eliminated and the position of the probe 10 has stabilized. The user then presses the switch 30 to start acquiring the measurement signal S1, and the fatigue level or remaining life of the bearing is determined.

[0041] Furthermore, if the raceway surface 61 is a cylindrical shape concentric with the central axis O2 of the outer ring 60, it is necessary to maintain the correct orientation in which the probe 10 is perpendicular to the raceway surface 61 during measurement. In this case, as shown in Figure 9, the central axis O1 of the probe body 11 and the central axis O2 of the outer ring 60 are perpendicular, two sides r1 and r2 of the four sides constituting the rectangle R that are parallel to each other are parallel to the central axis O2 of the outer ring 60, and the other two sides r3 and r4 of the four sides constituting the rectangle R that are parallel to each other are perpendicular to the central axis O2 of the outer ring 60. Then, the pair of protrusions 26, 26 on one side in the circumferential direction (upper side in Figure 9) are spaced apart with respect to the direction of the central axis O2 of the outer ring 60, and similarly, the pair of protrusions 26, 26 on the other side in the circumferential direction (lower side in Figure 9) are also spaced apart with respect to the direction of the central axis O2 of the outer ring 60. Note that the points where the four protrusions 26 contact the raceway surface 61 are different from when the raceway surface 61 is a concave sphere. If the raceway surface 61 is cylindrical, the four protrusions 26 contact the raceway surface 61 at their circumferential outer edges 26d, including the outer corners 26b.

[0042] Next, we will describe the case where the raceway surface 71 formed on the outer circumferential surface of the inner ring 70 is measured. Figure 10 is a cross-sectional view showing the probe in contact with the raceway surface of the inner ring perpendicularly. Figure 11 is a view in the direction of arrow XI in Figure 10. Figure 12 is a cross-sectional view taken along the line XII-XII in Figure 11. Figure 13 is a cross-sectional view taken along the line XIII-XIII in Figure 11. Figure 14 is an enlarged view of the probe in Figure 11. Figure 15 is a partially enlarged view of Figure 10.

[0043] In the illustrated example, the outer circumferential surface of the inner ring 70 has two rows of raceway surfaces 71, 71 formed thereon. These raceway surfaces 71 are convex curved surfaces. The shape of the raceway surfaces 71 is arbitrary and may be cylindrical, for example. As shown in Figures 10 to 15, during measurement, it is necessary to maintain the correct orientation in which the probe 10 is perpendicular to the raceway surfaces 71 of the inner ring 70. Therefore, the user adjusts the orientation of the probe 10 so that all four protrusions 26 of the abutment portion 15 contact the raceway surfaces 71 of the inner ring 70. Specifically, as shown in Figures 14 and 15, the central axis O1 of the probe body 11 and the normal direction O4 of the contact angle α of the inner ring 70 are perpendicular, two sides r1 and r2 of the four sides constituting the rectangle R that are parallel to each other are parallel to the normal direction O4 of the contact angle α, and the other two sides r3 and r4 of the four sides constituting the rectangle R that are parallel to each other are perpendicular to the normal direction O4 of the contact angle α.

[0044] Here, the normal direction O4 of the contact angle α will be explained with reference to Figure 15. In Figure 15, α is the contact angle, O3 is the central axis of the inner ring 70, O4 is the normal direction of the contact angle α, and O5 is the direction of the contact angle. The contact angle α is defined as the "nominal contact angle" described in the Japanese Industrial Standard JIS B 0104-1991 "Rolling Bearing Terminology," and is the angle formed by the plane S perpendicular to the central axis O3 of the inner ring 70 and the contact angle direction O5. The contact angle direction O5 is the direction of the line of action of the load, and is the direction of the force applied to the inner ring 70 from the rolling element (not shown). The normal direction O4 of the contact angle α is the direction that passes through the raceway surface 71 and is perpendicular to the contact angle direction O5. When the probe 10 is in the correct position perpendicular to the raceway surface 71, the central axis O1 of the probe body 11 coincides with the contact angle direction O5 and is perpendicular to the normal direction O4 of the contact angle α.

[0045] In this way, when the four protrusions 26 are brought into contact with the raceway surface 71, as shown in Figure 14, a pair of protrusions 26 are positioned on each side in the circumferential direction, straddling the direction O4 normal to the contact angle α. The pair of protrusions 26, 26 on one side in the circumferential direction (upper side in Figure 14) are spaced apart with respect to the direction O4 normal to the contact angle α, and similarly, the pair of protrusions 26, 26 on the other side in the circumferential direction (lower side in Figure 14) are spaced apart with respect to the direction O4 normal to the contact angle α of the inner ring 70.

[0046] The four protrusions 26 then contact the convex curved surface of the raceway 71 at their inner corners 26c. The inner corners 26c are the corners of the tip surface 26a of the protrusion 26 that are located outward with respect to the normal direction O4 of the contact angle α, and inward in the circumferential direction. By bringing the inner corners 26c of each of the four protrusions 26 into contact with the raceway 71 in this way, the probe body 11 can be kept perpendicular to the raceway 71, and stable measurement results can be obtained.

[0047] When the inner corners 26c of all four protrusions 26 come into contact with the raceway surface 71, the user can perceive that the wobbling of the probe 10 being held is eliminated and the position of the probe 10 has stabilized. The user then presses the switch 30 to start acquiring the measurement signal S1, and the fatigue level or remaining life of the bearing is determined.

[0048] Even when the raceway surface 71 is a cylindrical shape concentric with the central axis O3 of the inner ring 70, it is necessary to maintain the correct orientation in which the probe 10 is perpendicular to the raceway surface 71 during measurement. In this case, although not specifically shown in the figures, the central axis O1 of the probe body 11 and the central axis O3 of the inner ring 70 should be perpendicular, two sides r1 and r2 of the four sides constituting the rectangle R that are parallel to each other should be parallel to the central axis O3 of the inner ring 70, and the other two sides r3 and r4 of the four sides constituting the rectangle R that are parallel to each other should be perpendicular to the central axis O3 of the inner ring 70. Furthermore, the pair of protrusions 26, 26 on one side in the circumferential direction (upper side of Figure 14) should be spaced apart with respect to the central axis O3 of the inner ring 70, and similarly, the pair of protrusions 26, 26 on the other side in the circumferential direction (lower side of Figure 14) should also be spaced apart with respect to the central axis O3 of the inner ring 70. Note that the points where the four protrusions 26 contact the raceway surface 71 are different from when the raceway surface 71 is a convex sphere. If the raceway surface 71 is cylindrical, the four protrusions 26 contact the raceway surface 61 at their circumferential inner edges 26e (see Figure 14), including the inner corners 26c.

[0049] In the illustrated example, the shape of the abutment portion 15, as viewed from the axial direction, is rectangular, and the four protrusions 26 are positioned at the vertices of the rectangle of the abutment portion 15. Therefore, the four protrusions 26 can be provided on the abutment portion 15 in a space-efficient manner, and the distance between adjacent protrusions 26 can be increased to stabilize the posture of the probe 10.

[0050] Furthermore, the shape of the abutment portion 15 as viewed from the axial direction is not limited to a rectangle, but may be any shape, for example, circular for ease of manufacturing.

[0051] Furthermore, in the illustrated example, the shape of the tip surface 26a of the projection 26, as viewed from the axial direction, was rectangular. This allows the probe 10 to maintain a stable position when the surface to be measured is the raceway surface 61 of the outer ring 60, which is a concave spherical surface, by bringing the outer corners 26b of each of the four projections 26 into contact with the raceway surface 61. When the surface to be measured is the raceway surface 71 of the inner ring 70, which is a convex curved surface, the probe 10 can maintain a stable position by bringing the inner corners 26c of each of the four projections 26 into contact with the surface to be measured. In addition, although not specifically shown, when the surface to be measured is a flat surface, the probe 10 can maintain a stable position by bringing the entire tip surface 26a of the four projections 26 into contact with the surface to be measured.

[0052] Furthermore, the shape of the tip surface 26a of the projection 26 as viewed from the axial direction is not limited to a rectangle, but may be any shape, for example, it may be circular for ease of manufacturing.

[0053] In the illustrated example, the projection 26 is integrally provided with the abutment portion 15, but the projection 26 may be a separate pin from the abutment portion 15. In this case, the method of fixing the pin constituting the projection 26 is arbitrary, but examples include fixing by bonding it to the abutment portion 15, or fixing by press-fitting or screwing it into a hole formed in the abutment portion 15. By making the projection 26 a separate component in this way, it can be replaced if the projection 26 is damaged or worn. Furthermore, it is possible to replace it with an appropriate projection 26 for different measurement target surfaces according to their shape, roughness, and other characteristics.

[0054] As described above, the user confirms that the probe 10 is in correct contact with the raceway surface 61 of the outer ring 60 and the raceway surface 71 of the inner ring 70, and then presses the switch 30 to transition the determination device 1 to the measurement execution state. The inventors of the present invention realized that workability can be improved by attaching and detaching the switch 30 to the probe 10 depending on the usage situation of the probe 10. For example, when inserting the probe 10 into a narrow part such as the gap of a bearing to take a measurement, it is preferable to remove the switch 30 from the probe 10 for better workability. Also, for example, when supporting the bearing with the left hand and gripping the probe 10 with the right hand, it is preferable to have the switch 30 attached to the probe 10 so that the switch 30 can be pressed with the right hand. The configuration for making the switch 30 attachable and detachable from the probe 10 will be described in detail below.

[0055] Figure 16 shows the probe with the switch attached. Figure 17 shows the switch moved towards the tip of the probe from the state shown in Figure 16. Figure 18 is a perspective view of the switch from the front. Figure 19 is a perspective view of the switch from the back.

[0056] As shown in Figures 16 to 19, the switch 30 has a substantially annular ring portion 31 and a main body portion 32 on which a first button 33a, a second button 33b, a third button 33c, and a second button 33b are formed, which can be pressed by the user. In the illustrated example of the switch 30, the ring portion 31 and the main body portion 32 are separate components and can be attached to and detached from each other, but the ring portion 31 and the main body portion 32 may be formed as a single integrated component.

[0057] The ring portion 31 has a substantially annular shape with the central axis P at its center. Preferably, the ring portion 31 is made of an elastically deformable material. For example, it may be made of resin, rubber, string, tape, etc. If the ring portion 31 is elastically deformable, it is easy to attach the ring portion 31 to the probe 10 or the user's finger, etc.

[0058] The ring portion 31 includes a base portion 31a to which the main body portion 32 is fixed, and a pair of clamping pieces 31b, 31b connected to both ends of the base portion 31a, respectively, extending around the central axis P in a substantially C-shape in cross-section.

[0059] On the base portion 31a, the surface facing the main body portion 32 is provided with an engaging portion consisting of irregularities such as not shown. The engaging portion of the main body portion 32 engages with the engaging portion of the base portion 31a, thereby engaging the ring portion 31 and the main body portion 32 together and integrating them. The engagement between the engaging portion of the ring portion 31 and the engaging portion of the main body portion 32 is not limited to the fitting of the irregular shapes described above, but may also be achieved by means of hook and loop fasteners, magnets, etc.

[0060] Each clamping piece 31b has a recess 31c formed at its base end, which faces inward, and this recess 31c promotes the elastic deformation of the clamping piece 31b. The tips of the pair of clamping pieces 31b, 31b face each other with a gap T between them. As a result of this gap T, the ring portion 31 of the switch 30 has a shape in which a part of its circumferential direction is cut out.

[0061] The probe 10 or the user's finger is inserted into the internal space of the ring portion 31 between the pair of clamping pieces 31b, 31b, and the pair of clamping pieces 31b, 31b elastically clamp the probe 10 or the user's finger. Furthermore, since the probe 10 or the like can be inserted into the internal space of the ring portion 31 through the gap T, the insertion operation is very simple.

[0062] In particular, since the probe 10 has a cable 25, if a gap T is not formed, it is difficult to attach the ring portion 31 to the probe 10 from the base end side (upper side in Figures 16 and 17). However, with the ring portion 31 of this embodiment, the cable 25 can be passed through the notched portion (gap T) of the ring portion 31, making it easier to fix the ring portion 31 to the probe 10.

[0063] The ring portion 31 of the switch 30 is preferably 13mm to 30mm in length. By setting it to this size, the user can operate the switch 30 by putting the ring portion 31 on their finger.

[0064] The main body 32 is a roughly disc-shaped component, and a battery that supplies power to the main body 32 is housed inside. The first to third buttons 33a to 33c are formed on the front side of the main body 32, opposite to the ring portion 31. The second button 33b is provided in the center of the front side of the main body 32, and the first button 33a and the third button 33c are provided on both sides of the second button 33b in the direction of its central axis P.

[0065] The direction in which the central second button 33b is pressed is the radial direction Q (see Figure 16) with respect to the central axis P of the ring portion 31. That is, the direction in which the second button 33b is pressed has only a radial component parallel to the radial direction Q, and no axial component parallel to the central axis P. Therefore, the surface of the second button 33b is perpendicular to the radial direction Q.

[0066] In contrast, the surfaces of the first button 33a and the third button 33c on either side of the second button 33b are inclined surfaces that are tilted toward the central axis P with respect to the pressing surface of the second button 33b. As a result, the pressing direction of the first button 33a and the third button 33c has both an axial component parallel to the central axis P of the ring portion 31 and a radial component parallel to the radial direction Q. That is, when pressing the first button 33a and the third button 33c, the pressing is performed not only in the radial direction Q but also in the direction of the central axis P. By setting the pressing direction of the first button 33a and the third button 33c in this way, when the switch 30 is attached to the probe 10 as shown in Figures 16 and 17, the user can easily press the first button 33a and the third button 33c while holding the probe 10.

[0067] When at least one of the first to third buttons 33a to 33c is pressed, the main unit 32 transmits a measurement control signal S2 to the input unit 40 (see Figure 1) to switch the start and end of acquiring the impedance measurement signal S1 detected by the probe 10. At this time, the switch 30 transmits the measurement control signal S2 wirelessly. This prevents interference between the measurement signal S1 from the probe 10, which is transmitted via cable 25, and the measurement control signal S2 from the switch 30. In addition, since there is no wiring on the switch 30, it is easy to attach to the probe 10.

[0068] As described above, the switch 30 is detachable from the outer circumferential surfaces 13f and 13d of the housing 13 of the probe 10. Figures 16 and 17 show the switch 30 mounted on the outer circumferential surface 13f of the cylindrical base 13a of the housing 13, but the switch 30 may also be mounted on the outer circumferential surface 13d of the rectangular tip 13b.

[0069] However, since the user usually grips the base 13a rather than the tip 13b, it is preferable to mount the switch 30 on the outer circumferential surface 13f of the base 13a in order to make it easier to operate the switch 30 while gripping it. Also, since the outer circumferential surface 13f of the base 13a is a cylindrical surface, the substantially annular ring portion 31 of the switch 30 can be easily attached. On the other hand, if the cross-sectional shape is rectangular rather than circular, as is the case with the outer circumferential surface 13d of the tip 13b, the orientation must be properly aligned in order to attach the switch, making the installation work complicated.

[0070] A stepped portion 13c is formed between the outer peripheral surface 13f of the base portion 13a of the housing 13 and the outer peripheral surface 13d of the tip portion 13b, and Figure 17 shows the ring portion 31 in contact with this stepped portion 13c. In this way, the axial movement of the switch 30 is restricted by the stepped portion 13c, so that the switch 30 is less likely to shift when the user operates the switch 30 (especially when the first button 33a, which is pressed in the direction of the tip of the probe 10 is pressed), and usability is improved.

[0071] Although not specifically shown in the figures, the stepped portion is not limited to the stepped portion 13c shown in the figures, and its shape and arrangement are arbitrary as long as it can restrict the axial movement of the switch 30. For example, the stepped portion may be formed by recesses or protrusions provided on the outer circumferential surface 13f of the base portion 13a, or it may be formed by recesses or protrusions provided on the outer circumferential surface 13f of the tip portion 13b.

[0072] In the illustrated example, the ring portion 31 of the switch 30 is shown to be detachable from the probe 10, but the main body portion 32 of the switch 30 may also be detachable from the probe 10. That is, the ring portion 31 and the main body portion 32 of the switch 30 may be separate components, and a configuration may be adopted in which the main body portion 32 can be removed from the ring portion 31 and only the main body portion 32 can be attached to the housing 13 of the probe 10.

[0073] As described above, the surface of the base portion 31a facing the main body portion 32 is provided with an engaging portion consisting of irregularities, etc. (not shown). The engaging portion of the main body portion 32, consisting of irregularities, etc. (not shown), engages with the engaging portion of the base portion 31a, thereby engaging the ring portion 31 and the main body portion 32 together and integrating them. Therefore, although not specifically shown, if the outer circumferential surfaces 13d and 13f of the housing 13 of the probe 10 are provided with engaging portions consisting of irregularities, etc. similar to those of the base portion 31a, the engaging portion of the main body portion 32 of the switch 30 can be engaged with the engaging portion of the housing 13. Note that the engagement between the engaging portion of the housing 13 of the probe 10 and the engaging portion of the main body portion 32 is not limited to the fitting of irregularities as described above, but may also be achieved by means of hook and loop fasteners, magnets, etc.

[0074] In this way, by making the main body 32 of the switch 30 detachable from the ring portion 31 of the switch 30 and the outer surfaces 13d and 13f of the housing 13, the handling of the main body 32, which has the first to third buttons 33a to 33c, becomes easier. For example, the main body 32 can be removed from the ring portion 31 on the user's finger and attached to the housing 13 of the probe 10 while the ring portion 31 remains on the user's finger. Furthermore, the main body 32 can be removed from the housing 13 and attached to the ring portion 31 while it remains on the user's finger.

[0075] Furthermore, the present invention is not limited to the embodiments described above, and can be modified, improved, etc., as appropriate.

[0076] As described above, the following matters are disclosed in this specification: (1) A probe that induces eddy currents in a bearing by applying an alternating magnetic field and detects the impedance of the bearing, A switch that transmits a measurement control signal to switch the start and end of acquiring the impedance measurement signal detected by the probe, Based on the impedance of the bearing, a fatigue determination unit for determining the fatigue degree or remaining life of the bearing is provided. A determination device comprising, The fatigue determination unit is, A map storage unit that stores a determination map including the relationship between the impedance characteristics of the bearing and the fatigue degree or remaining life of the bearing, A measurement switching unit that switches between a measurement execution state and a measurement non-execution state based on the state of the measurement control signal, In the measurement execution state, a data holding unit holds the measurement signal, An impedance characteristic calculation unit calculates the impedance characteristics of the bearing based on the held measurement signal, A determination unit that determines the fatigue level or remaining life of the bearing based on the impedance characteristics of the bearing and the determination map, Equipped with, The aforementioned probe A probe body that contacts the surface of the bearing to be measured and detects the impedance of the bearing, A housing that is roughly cylindrical and has a hole inside for housing the probe body, Equipped with, The switch is detachable from the housing. Judgment device. (2) The switch is detachably attached to the outer surface of the housing, The outer circumferential surface of the housing is a cylindrical surface. (1) The determination device described above. (3) A stepped portion is formed on the outer circumferential surface of the housing. The determination device described in (1) or (2). (4) The switch transmits the measurement control signal wirelessly. A determination device as described in any one of (1) to (3). (5) The switch is A substantially annular ring portion that is detachably attached to the outer circumferential surface of the housing, The main body has buttons that the user can press, including, A determination device as described in any one of (1) to (4). (6) The ring portion of the switch has an inner diameter of 13 mm to 30 mm. (5) The determination device described above. (7) The ring portion of the switch is made of an elastically deformable material. The determination device described in (5) or (6). (8) The ring portion of the switch has a part cut out in the circumferential direction. A determination device as described in any one of (5) to (7). (9) The direction in which the button on the main body of the switch is pressed has an axial component parallel to the central axis of the ring portion and a radial component parallel to the radial direction with respect to the central axis of the ring portion. A determination device as described in any one of (5) to (8). (10) The ring portion and the main body portion of the switch are separate components, The main body portion is detachably attached to the ring portion and the outer circumferential surface of the housing. A determination device as described in any one of (5) to (9).

[0077] This application is based on Japanese Patent Application No. 2024-036004 filed on March 8, 2024, and its contents are incorporated herein by reference. [Explanation of symbols]

[0078] 1 Judgment device 10 probes 11. Probe body 13 Housing 13a base 13b Tip 13c Step section 13d Outer surface of the tip 13e long hole 13f Outer surface of the base 13f Outer surface of the base 14 Sliding hole (hole) 14a Opening at the tip 14b Base opening 15. Assault Section 17. Coil spring (biasing spring) 21 Probe section 22 Holder part 22a Female threaded hole 24 pins 25 Cables 26 Protrusion 26a Tip surface 26b Outer corner 26c inner corner 26d Outer edge in the circumferential direction 26e Circumferential inner side 30 switches 31 Ring section 31a Base 31b Clamping piece 31c recess 32 Main body 33a First button 33b Second button 33c Third button 40 Input section 50 Fatigue determination unit 51 Map memory unit 53 Measurement switching section 55 Data storage unit 57 Impedance characteristic calculation unit 58 Display section 59 Judgment section 60 Outer ring (bearing) 61. Track surface (surface to be measured) 70 Inner ring (bearing) 71. Track surface (surface to be measured) O1 Probe body central axis O2 Outer ring central axis O3 Inner ring center axis O4 Normal direction of the contact angle O5 contact angle direction P switch ring section central axis Q: Radial direction of the ring portion of the switch T gap

Claims

1. A probe that induces eddy currents in a bearing by applying an alternating magnetic field and detects the impedance of the bearing, A switch that transmits a measurement control signal to switch the start and end of acquiring the impedance measurement signal detected by the probe, Based on the impedance of the bearing, a fatigue determination unit for determining the fatigue degree or remaining life of the bearing is provided. A determination device comprising, The fatigue determination unit is, A map storage unit that stores a determination map including the relationship between the impedance characteristics of the bearing and the fatigue degree or remaining life of the bearing, A measurement switching unit that switches between a measurement execution state and a measurement non-execution state based on the state of the measurement control signal, In the measurement execution state, a data holding unit holds the measurement signal, An impedance characteristic calculation unit calculates the impedance characteristics of the bearing based on the held measurement signal, A determination unit that determines the fatigue level or remaining life of the bearing based on the impedance characteristics of the bearing and the determination map, Equipped with, The aforementioned probe A probe body that contacts the surface of the bearing to be measured and detects the impedance of the bearing, A housing that is roughly cylindrical and has a hole inside for housing the probe body, Equipped with, The switch is detachable from the housing and transmits the measurement control signal wirelessly. Judgment device.

2. The switch is detachably attached to the outer surface of the housing. The outer circumferential surface of the housing is a cylindrical surface. The determination device according to claim 1.

3. A stepped portion is formed on the outer circumferential surface of the housing. The determination device according to claim 1.

4. The aforementioned switch is A substantially annular ring portion that is detachably attached to the outer circumferential surface of the housing, The main body has buttons that the user can press, including, The determination device according to claim 1.

5. The ring portion of the aforementioned switch has an inner diameter of 13 mm to 30 mm. The determination device according to claim 4.

6. The ring portion of the switch is made of an elastically deformable material. The determination device according to claim 4.

7. The ring portion of the aforementioned switch has a portion cut out in the circumferential direction. The determination device according to claim 4.

8. The direction in which the button on the main body of the switch is pressed has an axial component parallel to the central axis of the ring portion and a radial component parallel to the radial direction with respect to the central axis of the ring portion. The determination device according to claim 4.

9. The ring portion and the main body portion of the switch are separate components. The main body portion is detachably attached to the ring portion and the outer circumferential surface of the housing. The determination device according to claim 4.

Images