Friction testing device and friction testing method

Abstract

To provide a friction testing device and a friction testing method with which, while continuously observing during a friction test a sliding region where members are in contact and sliding on each other, it is possible to measure the temperature in the sliding region at the same time.SOLUTION: A friction testing device 1 is designed to cause a first sliding member 21 and a second sliding member 22 to slide relatively on each other, and to measure the friction force of the sliding region. The friction testing device 1 includes a dichroic mirror 4 that passes one of an infrared light L1 and a visible light L2 through and reflects the other of these. The first sliding member 21 is located on the dichroic mirror 4 side with respect to the second sliding member 22 and passes the infrared light L1 and the visible light L2 through. The friction testing device 1 irradiates the sliding region with the infrared light L1 and the visible light L2 via the dichroic mirror 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a friction test apparatus and a friction test method, and more particularly, to a friction test apparatus and a friction test method that allows observation of a sliding area using the friction test apparatus. [Background technology]

[0002] The ball-on-disk friction test is known as a friction testing method for measuring the friction force and friction coefficient under certain conditions when parts slide against each other. In the ball-on-disk friction test, a ball is placed in contact with one side of a disk and rotated to generate friction between the ball and the disk, and the friction force and friction coefficient at that time are measured.

[0003] In a friction test, it is very important to observe the state of the friction interface during the test. For example, Patent Document 1 discloses an observation device for observing the free interface of a fluid sample that has passed through the contact area where a movable member and a contact member come into contact during a friction test. However, the method of Patent Document 1 only observes the area that has passed through the contact area, and cannot observe the friction interface during sliding.

[0004] Patent Document 2 discloses that in a friction testing method in which a spherical pressing member is slid against an electron-transparent film, an observation method is used in which an electron beam is irradiated onto the friction interface from the electron-transparent film side, and electrons or electromagnetic waves generated at the friction interface are detected to obtain an image of the sliding area, making it possible to observe submicron-order phenomena that occur at the friction interface during friction.

[0005] In addition, in a friction test, it is very important to measure the temperature of the friction interface during the test. Conventionally, a contact thermometer such as a thermocouple or an infrared radiation thermometer has been used to measure the temperature of the sliding area. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-92536 A [Patent Document 2] JP 2020-180925 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, it has not been possible to continuously observe the sliding area (friction interface) where members are in contact with each other and slide against each other while simultaneously measuring the temperature of the sliding area.

[0008] Therefore, an object of the present disclosure is to provide a friction testing device and a friction testing method that are capable of continuously observing a sliding area where members are in contact with each other and sliding against each other during a friction test while simultaneously measuring the temperature of the sliding area. [Means for solving the problem]

[0009] As a result of intensive research to solve the above problems, the inventors of the present disclosure have found that by using a dichroic mirror that transmits one of infrared light and visible light and reflects the other, and by using a sliding member that transmits infrared light and visible light, it is possible to continuously observe the sliding region where the members are in contact with each other and sliding against each other during a friction test, while simultaneously measuring the temperature of the sliding region. The present disclosure relates to a product that has been completed based on these findings.

[0010] That is, the present disclosure provides a friction testing device for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, comprising: a dichroic mirror that transmits one of infrared light and visible light and reflects the other, the first sliding member is located on the dichroic mirror side with respect to the second sliding member and transmits infrared light and visible light; A friction testing device is provided that irradiates the sliding area with infrared light and visible light via the dichroic mirror.

[0011] It is preferable that the friction test apparatus includes a microscopic radiation thermometer and a visible light source, and the dichroic mirror, the microscopic radiation thermometer, and the visible light source are designed in positions where the infrared rays and the visible light are coaxially irradiated and incident on the sliding region.

[0012] A ball-on-disk friction test may be performed in which the first sliding member is a disk and the second sliding member is a ball.

[0013] The dichroic mirror is preferably located vertically above the sliding area.

[0014] The dichroic mirror preferably transmits infrared light and reflects visible light.

[0015] The present disclosure also provides a friction testing method for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, comprising the steps of: A friction testing method is provided in which the frictional force is continuously measured while irradiating the sliding area with infrared and visible light via a dichroic mirror and transmitted through the first sliding member.

[0016] In the above friction test method, it is preferable that the infrared rays and the visible light are coaxially irradiated onto and incident on the sliding area.

[0017] In the friction testing method, it is preferable that the dichroic mirror transmits one of infrared light and visible light and reflects the other, thereby irradiating the sliding area with infrared light and visible light.

[0018] A ball-on-disk friction test may be performed in which the first sliding member is a disk and the second sliding member is a ball. Effect of the Invention

[0019] According to the friction test apparatus and friction test method of the present disclosure, it is possible to continuously observe the sliding area where the members are in contact with each other and sliding against each other during the friction test while simultaneously measuring the temperature of the sliding area. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a front view of one embodiment of a friction testing apparatus of the present disclosure. [Diagram 2] 1 is a graph showing the relationship between load and friction coefficient obtained in an example. [Diagram 3] 1 is a graph showing the relationship between the load and the temperature of the sliding region obtained in an example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The friction test apparatus of the present disclosure is a friction test apparatus for measuring the friction force of a sliding region (friction region) by sliding a first sliding member and a second sliding member relative to each other. According to the friction test apparatus of the present disclosure, the sliding region where the members are in contact with each other and sliding against each other can be continuously observed while simultaneously measuring the temperature of the sliding region.

[0022] The friction test method of the present disclosure is a friction test method for measuring the frictional force of a sliding region by sliding a first sliding member and a second sliding member relative to each other, and irradiating the sliding region with infrared light and visible light through a dichroic mirror and the first sliding member while continuously measuring the frictional force. The friction test method can be performed using the friction test device.

[0023] The friction test device and the friction test method will be described below with reference to the embodiments. Fig. 1 shows a schematic diagram (front view) of one embodiment of the friction test device of the present disclosure. The friction test device 1 shown in Fig. 1 includes a first sliding member 21, a second sliding member 22, a first fixing member 31, a second fixing member 32, a dichroic mirror 4, a microscopic radiation thermometer 5, a lens 6, a visible light source 7, a motor 8, and a friction force detection unit (not shown) that measures the friction force of the sliding region.

[0024] The first sliding member 21 is located on the dichroic mirror 4 side with respect to the second sliding member 22. The first sliding member 21 is plate-shaped (disk-shaped) and is supported by a first fixing member 31 that is connected to the center of the first sliding member 21 and fixes the first sliding member 21 so that it can rotate in a horizontal plane. The first fixing member 31 is columnar and can be rotated in a horizontal plane by a motor 8. By rotating the first fixing member 31, the first sliding member 21 can be rotated, and the first sliding member 21 can be slid with the second sliding member 22.

[0025] The second sliding member 22 is a ball having a spherical surface, and is located vertically below the disk-shaped first sliding member 21, and is located on the opposite side of the dichroic mirror 4 with respect to the first sliding member 21, and is fixed by a second fixing member 32 so as to be able to slide on the lower surface of the first sliding member 21. The dichroic mirror 4 and the second sliding member 22 are positioned above and below in the vertical direction. Note that the second sliding member 22 being a ball means that the sliding surface is spherical, and may be, for example, hemispherical.

[0026] 1 is a ball-on-disk friction test device in which the first sliding member 21 is a disk and the second sliding member 22 is a ball, but the first sliding member 21 may be a ball and the second sliding member 22 may be a disk, and further, the friction test device 1 of the present disclosure is not limited to a ball-on-disk friction test device, and may be a friction test device that measures frictional force by other principles such as a ring-on-disk (ring-on-plate) friction test, a pin-on-disk friction test, a ball-on-plate friction test, a pin-on-plate friction test, or a fretting friction test. In the case of such other friction test devices, the sliding mechanism can be appropriately designed using a known or commonly used method based on the other principles.

[0027] The dichroic mirror 4 is located on the opposite side of the first sliding member 21 to the second sliding member 22, and is located vertically above the first sliding member 21 in FIG. 1, more specifically, vertically above the sliding region. The dichroic mirror transmits one of infrared light and visible light and reflects the other. That is, the dichroic mirror transmits at least a part of the wavelengths of infrared light and reflects at least a part of the wavelengths of visible light, or transmits at least a part of the wavelengths of visible light and reflects at least a part of the wavelengths of infrared light. In the former case (that is, in the case of FIG. 1 where the dichroic mirror transmits infrared light), the infrared light L1 emitted from the sliding region of the first sliding member 21 is transmitted through the dichroic mirror 4 and enters the microscopic radiation thermometer 5. Also, the visible light L2 emitted from the visible light source 7 is reflected by the dichroic mirror 4 and irradiated onto the first sliding member 21. In the latter case (i.e., when the dichroic mirror reflects infrared rays), the positions of the microscopic radiation thermometer 5 and the lens 6 shown in FIG. 1 are reversed. That is, the microscopic radiation thermometer is at the position 6, and the lens is at the position 6. In this case, the infrared rays emitted from the sliding area of ​​the first sliding member 21 are reflected by the dichroic mirror and enter the microscopic radiation thermometer. Also, the visible light emitted from the visible light source is transmitted through the dichroic mirror and irradiated onto the first sliding member 21. Here, the first sliding member 21 transmits infrared rays and visible light. Therefore, the visible light irradiated onto the first sliding member 21 transmits through the first sliding member 21 and irradiates the sliding areas of the first sliding member 21 and the second sliding member 22. In this way, the visible light is irradiated onto the sliding area via the dichroic mirror, and the first sliding member 21 transmits the visible light reflected on the surface of the second sliding member 22 and the infrared rays L1 radiated from the sliding area.

[0028] The dichroic mirror 4, the microscopic radiation thermometer 5, and the visible light source 7 are preferably designed at positions where the infrared light L1 and the visible light L2 are coaxially irradiated and incident on the sliding area. By making them coaxial, the temperature of the observation area can be measured more accurately. The microscopic radiation thermometer 5, the dichroic mirror 4, and the sliding area are positioned in a straight line in this order. When the dichroic mirror transmits visible light, it is preferable that the visible light source, the dichroic mirror, and the sliding area are positioned in a straight line in this order.

[0029] The visible light irradiated to the sliding area is reflected and enters the dichroic mirror 4 again. In addition, the infrared light irradiated from the sliding area also enters the dichroic mirror 4. At this time, the infrared light and the visible light are transmitted through the dichroic mirror 4 or reflected by the dichroic mirror 4, respectively, and the infrared light L1 enters the microscopic radiation thermometer 5, and the visible light L2 enters the lens 6. In this way, while the first sliding member 21 and the second sliding member 2 are sliding, the sliding area can be continuously observed and the temperature of the sliding area can be measured at the same time. In addition, the friction force in the sliding area can be measured at the same time by the friction force detection unit. The visible light source 7 and the lens 6 are located on the same axis of the visible light irradiated by the visible light source 7.

[0030] In addition, in Fig. 1, the lens 6 may be a camera, and the lens 6 and the visible light source 7 may be integrated. For example, a visible camera / coaxial visible light source can be used as the lens 6 and the visible light source 7. In addition, in Fig. 1, the visible light irradiated by the visible light source 7 and the visible light incident on the lens 6 are preferably coaxial, but the visible light irradiated by the visible light source 7 may indirectly irradiate the sliding region.

[0031] Examples of the lens 6 include objective lenses, and lenses of optical devices capable of capturing images, such as camera lenses and video camera lenses. The friction test device may include an electronic device having a detection unit capable of detecting light, such as an imaging device such as a camera or video camera. The electronic device is installed so as to include the lens 6 as a part thereof, or at a location where reflected light that has passed through the lens 6 can be detected.

[0032] The material of the first sliding member 21 may be any known or commonly used material that is capable of transmitting infrared rays and visible light, and may be any of metal, resin, and rubber. Specific examples of the material of the first sliding member 21 include CaF2, ZnSe, diamond, ZnS, and chalcogenide glass. The surface of these materials may be coated with a material such as chrome plating or a diamond-like carbon film within a range that does not impede the transmission of infrared rays and visible light.

[0033] The material of the second sliding member 22 may be selected based on the object for which the frictional force is to be measured. For example, crystalline resins such as POM (polyacetal), PE (polyethylene), PP (polypropylene), PA (polyamide), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), PEK (polyether ketone), LCP (liquid crystal polymer), and PTFE (polytetrafluoroethylene), PVC (polyvinyl chloride), Examples of materials include resins such as PS (polystyrene), PMMA (polymethyl methacrylate), ABS (acrylonitrile butadiene styrene), PC (polycarbonate), m-PPE (modified polyphenylene ether), PES (polyethersulfone), PSU (polysulfone), PEI (polyetherimide), PAI (polyamideimide), and other amorphous resins; typical metals such as steels such as SS400 and SUJ2, aluminum, nickel, and copper; and glasses such as borosilicate glass, quartz glass, and sapphire glass.

[0034] The dichroic mirror 4 may be any known or conventional mirror, such as germanium, CaF2, diamond, KBr, BaF2, silicon, sapphire, ZnSe, ZnS, chalcogenide glass, or other mirrors made of a visible light or infrared ray-transmitting substrate coated with various coatings to reflect specific wavelengths. Depending on the arrangement of the microscopic radiation thermometer and the lens / camera, the dichroic mirror may be either one that transmits infrared rays and reflects visible light, or one that transmits visible light and reflects infrared rays.

[0035] The friction test device may include a load application mechanism. An example of the load application mechanism is a mechanism that applies a load to the first sliding member 21 side of the second sliding member 22. The load in the friction test is not particularly limited, and a load according to the friction force to be measured can be appropriately selected. In addition, the sliding speed (for example, the rotation speed of the disk in a ball-on-disk friction test) is not particularly limited, and can be appropriately set.

[0036] In the above friction test method, the sliding of the first sliding member and the second sliding member may be performed in the presence of a lubricant or a lubricant for initial break-in. Moreover, the above friction test method can be performed in any friction environment, such as dry friction, in a lubricating oil, or in a vacuum.

[0037] Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Each configuration in each embodiment and their combinations are merely examples, and addition, omission, substitution, and other modifications of the configuration are possible as appropriate within the scope of the present disclosure. In addition, each invention according to this disclosure is not limited by the embodiments or the following examples, but is limited only by the claims. EXAMPLES

[0038] Hereinafter, one embodiment of the present disclosure will be described in more detail based on examples.

[0039] Example 1 A ball-on-disk friction test was performed using a friction tester shown in FIG. 1. A CaF2 plate was used as the first sliding member 21, and a polyacetal (POM) (trade name "Duracon M90-44", manufactured by Polyplastics Co., Ltd.) hemisphere with a spherical sliding surface was used as the second sliding member 22. Germanium was used as the dichroic mirror 4. The ball-on-disk friction test was performed for a predetermined time under the load conditions and disk rotation speed conditions shown in FIGS. 2 and 3 without using any lubricant. Visible light L2 was irradiated from the visible light source 7 and reflected by the dichroic mirror 4, and the visible light was coaxially irradiated onto the friction interface. In this way, from the start to the end of the friction test, the infrared ray irradiated from the friction interface was incident on the microscopic radiation thermometer 5, and the visible light L2 was incident on the lens 6, so that the friction force and temperature of the friction interface were continuously measured, and a video of the friction interface was simultaneously taken. A graph showing the relationship between the obtained load and friction coefficient is shown in FIG. 2, and a graph showing the relationship between the load and the temperature of the sliding area is shown in FIG. 3.

[0040] As shown in Fig. 2, a ball-on-disk friction test was performed using the friction test device of the present disclosure, and the friction coefficients at loads of 5 N and 10 N could be measured. Also, as shown in Fig. 3, the temperature of the sliding area during the friction test could be continuously measured, and the average and maximum values ​​during that time could be measured. Also, a video of the sliding area could be taken during the friction test.

[0041] Variations of the invention according to the present disclosure are described below. [Appendix 1] A friction testing device for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, a dichroic mirror that transmits one of infrared light and visible light and reflects the other, the first sliding member is located on the dichroic mirror side with respect to the second sliding member and transmits infrared light and visible light; A friction testing device that irradiates the sliding area with infrared light and visible light through the dichroic mirror. [Appendix 2] The friction testing device according to Appendix 1, further comprising a microscopic radiation thermometer and a visible light source, the dichroic mirror, the microscopic radiation thermometer, and the visible light source being designed in positions where the infrared rays and the visible light are coaxially irradiated to and incident on the sliding region. [Appendix 3] The friction testing apparatus according to appendix 1 or 2, which performs a ball-on-disk friction test in which the first sliding member is a disk and the second sliding member is a ball. [Appendix 4] The friction testing device according to any one of Appendices 1 to 3, wherein the dichroic mirror is positioned vertically above the sliding area. [Appendix 5] The friction testing device according to any one of Appendices 1 to 3, wherein the dichroic mirror transmits infrared light and reflects visible light. [Appendix 6] A friction testing method for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, comprising: the frictional force being continuously measured while irradiating the sliding area with infrared and visible light via a dichroic mirror and transmitted through the first sliding member. [Appendix 7] The friction testing method according to Appendix 6, wherein the infrared light and the visible light are coaxially irradiated and incident on the sliding area. [Appendix 8] The friction testing method according to appendix 6 or 7, wherein the dichroic mirror transmits one of infrared light and visible light and reflects the other, thereby irradiating the sliding area with infrared light and visible light. [Appendix 9] The friction testing method according to any one of Appendices 6 to 8, further comprising a ball-on-disk friction test in which the first sliding member is a disk and the second sliding member is a ball. [Explanation of symbols]

[0042] 1 Friction test equipment 21 First sliding member 22 Second sliding member 31 First fixing member 32 Second fixing member 4 Dichroic mirror 5. Microscopic radiation thermometer 6 Lenses 7 Visible light source 8 Motor

Claims

1. A friction testing device for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, comprising: a dichroic mirror that transmits one of infrared light and visible light and reflects the other, the first sliding member is located on the dichroic mirror side with respect to the second sliding member and transmits infrared light and visible light; A friction testing device that irradiates the sliding area with infrared light and visible light through the dichroic mirror.

2. 2. The friction testing device according to claim 1, further comprising a microscopic radiation thermometer and a visible light source, the dichroic mirror, the microscopic radiation thermometer, and the visible light source being designed in positions such that the infrared rays and the visible light are coaxially irradiated and incident on the sliding region.

3. 3. The friction testing device according to claim 1, wherein a ball-on-disk friction test is performed in which the first sliding member is a disk and the second sliding member is a ball.

4. 3. The friction testing device according to claim 1, wherein the dichroic mirror is positioned vertically above the sliding area.

5. 3. The friction testing device according to claim 1, wherein the dichroic mirror transmits infrared light and reflects visible light.

6. A friction testing method for measuring a friction force in a sliding region by sliding a first sliding member and a second sliding member relative to each other, comprising the steps of: the frictional force being continuously measured while irradiating the sliding area with infrared and visible light via a dichroic mirror and transmitted through the first sliding member.

7. 7. The friction testing method according to claim 6, wherein the infrared rays and the visible light are coaxially irradiated and incident on the sliding area.

8. 8. The friction testing method according to claim 6, wherein the dichroic mirror transmits one of infrared light and visible light and reflects the other, thereby irradiating the sliding area with infrared light and visible light.

9. 8. The friction testing method according to claim 6, further comprising the step of performing a ball-on-disk friction test in which the first sliding member is a disk and the second sliding member is a ball.

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