Scratch test machine and scratch test method

Abstract

Provided is a scratch test machine which is configured so that a needle scratches a surface of an evaluation subject by being pressed against the same, and which comprises: a pressing mechanism that has the needle attached to the lower end thereof, and that presses the needle against the surface with a constant load; and a support part that supports the pressing mechanism. The support part supports the pressing mechanism in a state in which the pressing mechanism is in contact with the surface at at least three locations.

Description

Scratch tester and scratch test method

[0001] The present disclosure relates to a scratch tester and a scratch test method.

[0002] A scratch tester used to evaluate a film formed on the upper surface of a magnetic disk substrate is known (see, for example, Patent Document 1). The scratch test is performed by an operator pressing the needle of the scratch tester against the surface of the evaluation object to scratch it. When scratching a curved surface such as an eyeglass lens as the evaluation object, the needle of the scratch tester may not hit the curved surface at a consistent angle. Therefore, the scratch tester may not be suitable for scratch testing a curved surface.

[0003] Japanese Patent Application Laid-Open No. 2001-091444

[0004] According to a first aspect of the present disclosure, there is provided a scratch tester that presses a needle against a surface to be evaluated to scratch it, the scratch tester comprising: a pressing mechanism having the needle attached to a lower end thereof and pressing the needle against the surface with a constant load; and a support part that supports the pressing mechanism, the support part supporting the pressing mechanism while contacting the surface at three or more points.

[0005] According to a second aspect of the present disclosure, there is provided a scratch testing method using a scratch tester that presses a needle against a surface to be evaluated to scratch it, the scratch tester having three or more wheels that can run on the surface, and including: pressing the needle against the surface with a constant load while all of the wheels are in contact with the surface; and moving the scratch tester using the wheels while pressing the needle against the surface with the constant load.

[0006] 1 is a schematic perspective view of a scratch tester according to the present embodiment. FIG. 2 is a schematic front view of a scratch tester according to the present embodiment. FIG. 3 is a schematic front sectional view of a scratch tester according to the present embodiment. FIG. 4 is a schematic side view of a scratch tester according to the present embodiment. FIG. 5 is a schematic sectional plan view taken along line L-L in FIG. 3. FIG. 6 is a diagram showing the state of the scratch tester when the needle according to the present embodiment comes into contact with the surface to be evaluated. FIG. 7 is a flow diagram of a scratch test method according to the present embodiment. FIG. 8 is a diagram showing a first modified example of a scratch tester according to the present embodiment. FIG. 9 is a diagram showing a second modified example of a scratch tester according to the present embodiment. FIG. 10 is a diagram showing a third modified example of a scratch tester according to the present embodiment. FIG. 11 is a diagram showing a fourth modified example of a scratch tester according to the present embodiment.

[0007] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0008] 1 is a perspective view of a scratch tester according to the present embodiment. The scratch tester 1 according to the present embodiment is used for a scratch test in which a needle is pressed against and scratched on a surface to be evaluated (hereinafter referred to as "evaluation target surface"). For example, the evaluation target surface is the surface of an eyeglass lens, but is not limited thereto and may be the surface of a substrate such as a glass plate or a film.

[0009] The scratch tester 1 is suitable for scratching a curved surface such as an eyeglass lens as the surface to be evaluated. That is, even when scratching a curved surface such as an eyeglass lens, the scratch tester 1 can bring the needle into contact with the curved surface at a constant angle. The scratch tester 1 is not only used when the surface to be evaluated is a curved surface, but can also be used when the surface to be evaluated is flat. The scratch tester 1 can bring the needle into contact with the surface to be evaluated at a constant angle, whether the surface to be evaluated is a horizontal surface or a curved surface.

[0010] The following description will be given taking the example of an eyeglass lens as the object to be evaluated. The surface of an eyeglass lens is usually coated with a thin film. As an example, as shown in FIG. 1 , an operator holds a scratch tester 1 and scratches the surface of the eyeglass lens with the needle of the scratch tester 1 to evaluate the scratch resistance of the coating.

[0011] Fig. 2 is a schematic front view of the scratch tester 1 according to this embodiment. Fig. 3 is a schematic front cross-sectional view of the scratch tester 1 according to this embodiment. Fig. 4 is a schematic side view of the scratch tester 1 according to this embodiment. Fig. 5 is a schematic cross-sectional plan view taken along line L-L in Fig. 3.

[0012] The scratch tester 1 includes a scratch needle unit 100 and a support part 200 .

[0013] The scratching needle unit 100 has, for example, a shape that is long in a predetermined direction. The scratching needle unit 100 shown in Fig. 1 has a pen-like shape. However, the scratching needle unit 100 is not limited to a pen shape and may have, for example, a rectangular column, a cone, or a pyramid shape.

[0014] The scratching needle unit 100 is supported by a support portion 200. The scratching needle unit 100 includes, for example, a needle 110 and a pressing mechanism 120.

[0015] The needle 110 is provided at the lower end of the pressing mechanism 120. The pressing mechanism 120 presses the needle 110 against the surface of the eyeglass lens with a constant load.

[0016] As shown in FIG. 3, the pressing mechanism 120 includes a case 130, a pressure screw 131, a spring 132, a movable part 133, and a needle support part 134.

[0017] The case 130 is cylindrical. The case 130 is, for example, a molded resin product made of a metal such as stainless steel or an aluminum alloy, or a synthetic resin mixed with a conductive material such as carbon powder. The case 130 houses the pressure screw 131, the spring 132, the movable part 133, and the needle support part 134. The case 130 has an elongated pen shape, and has a shape suitable for an operator to hold the scratch tester 1. However, the shape of the case 130 is not limited to a pen shape, and may be any shape suitable for an operator to hold the scratch tester 1.

[0018] The pressure screw 131 is threaded into the case 130. The pressure screw 131 is, for example, a hexagon socket set screw. The position of the pressure screw 131 inside the case 130 is adjustable. By setting the position of the pressure screw 131 to an arbitrary position, it is possible to adjust the load when the pressing mechanism 120 presses the needle 110 against the surface of the eyeglass lens. The position of the pressure screw 131 is adjusted manually, for example.

[0019] The upper end of the spring 132 is in contact with the lower end of the pressure screw 131. The upper end of the spring 132 may be fixed to the lower end of the pressure screw 131, or may be disposed so as to be in contact with the lower end of the pressure screw 131 without being fixed.

[0020] A movable part 133 is provided at the lower end of the spring 132. The needle 110 is fixed to the movable part 133. Specifically, the lower end of the spring 132 is attached to the upper part of the movable part 133, and the base end of the needle 110 is attached to the lower part of the movable part 133. The base end of the needle 110 fixed to the lower part of the movable part 133 is the end opposite to the tip of the needle 110. The movable part 133 is slidable within the case 130 in the longitudinal direction of the case 130. The longitudinal direction of the case 130 may also be referred to as the front-rear direction. In the front-rear direction, the direction toward the side where the needle 110 is provided is referred to as the front direction, and the direction toward the opposite side (the side where the pressure screw 131 is provided) is referred to as the rear direction. The shape of the movable part 133 is not particularly limited, and may be, for example, a cylindrical or rectangular column.

[0021] Needle support portion 134 is provided at the bottom end of case 130. Needle support portion 134 supports needle 110 so that it can slide back and forth in the front-to-rear direction. An opening is formed in needle support portion 134, and the tip of needle 110 protrudes from this opening. As an example, needle support portion 134 has a cylindrical through-hole 140. Needle 110 is inserted into this through-hole 140.

[0022] The through hole 140 includes a first opening 141 having a diameter smaller than the inner diameter of the case 130, and a second opening 142 having an even smaller diameter than the first opening 141. The second opening 142 is in communication with the first opening 141 and is located forward of the first opening 141. In other words, the needle support portion 134 has a through hole 140 whose diameter gradually decreases toward the front. Because two openings with different diameters are in communication in this manner, a step 150 is formed at the connection between the first opening 141 and the second opening 142. The diameters of the first opening 141 and the second opening 142 may be set according to the shape of the needle 110.

[0023] The needle 110 has a protruding portion that protrudes in the radial direction between the base end and the tip end. The needle 110 illustrated in this embodiment has an annular step 111 formed between the base end and the tip end. For example, the step 111 is formed by reducing the diameter of the needle 110 in a stepped manner from the base end to the tip end.

[0024] The step 111 is an example of the protrusion. When the needle 110 is inserted into the through-hole 140, the protrusion formed on the needle 110 hits the step 150 formed at the connection between the first opening 141 and the second opening 142, thereby restricting the forward sliding movement of the needle 110. The tip of the needle 110 always protrudes from the second opening 142 and can come into contact with the surface to be evaluated.

[0025] The support unit 200 supports the pressing mechanism 120. The support unit 200 supports the pressing mechanism 120 in a state of contact with the evaluation target surface at three or more locations. In this embodiment, the support unit 200 supports the pressing mechanism 120 in the vertical direction.

[0026] The support unit 200 includes a fixed unit 210 and a traveling carriage 220. The traveling carriage 220 is an example of a traveling body.

[0027] The fixed part 210 is attached to the traveling carriage 220. The fixed part 210 fixes the pressing mechanism 120 so that the longitudinal direction of the pressing mechanism 120 is vertical. For example, the fixed part 210 is an annular member that supports the pressing mechanism 120 in the vertical direction by tightening it against the pressing mechanism 120. The fixed part 210 is, for example, a set collar.

[0028] The traveling carriage 220 includes a traveling platform 230 and four wheels 240 .

[0029] A fixing part 210 is fixed to the upper surface of the running platform 230. A through hole is formed in the running platform 230, and the pressing mechanism 120 fixed by the fixing part 210 is inserted into the through hole. Four wheels 240 are rotatably attached to the running platform 230.

[0030] 5, two pairs of left and right wheels are arranged side by side in the traveling direction on the running platform 230. Each of the four wheels 240 is in contact with the surface of the eyeglass lens with the needle 110 pressed against the surface. That is, as an example of this embodiment, the support part 200 of the scratch tester 1 supports the pressing mechanism 120 that presses the needle 110 against the surface of the eyeglass lens while contacting the surface at four points.

[0031] The four wheels 240 are arranged to surround the needle 110. For example, as shown in Fig. 5, in a plan view, the needle 110 is arranged within an area H1 formed by connecting the centers of the four wheels with a straight line. More preferably, in a plan view, the needle 110 is arranged at the center position of the area H1.

[0032] A scratch test method using the scratch tester 1 according to this embodiment will be described below. Fig. 6 is a diagram showing the state of the scratch tester 1 when the needle 110 according to this embodiment comes into contact with the surface to be evaluated. Fig. 7 is a flow chart of the scratch test method according to this embodiment.

[0033] First, as shown in Fig. 1, an operator grasps the pressing mechanism 120 of the scratch tester 1 and brings the four wheels 240 into contact with the surface of the eyeglass lens (step S101). In the initial state where the four wheels 240 are not in contact with anything, the tip position of the needle 110 in the vertical direction is located below the bottom ends of the four wheels 240. Therefore, when the four wheels 240 are brought into contact with the surface of the eyeglass lens, the tip of the needle 110 comes into contact with the surface to be evaluated and is pushed up backward, and as the needle 110 moves, the movable part 133 moves backward (vertically upward in Fig. 6).

[0034] When movable part 133 moves rearward, spring 132 contracts by the amount of movement of movable part 133. Then, pressing mechanism 120 presses the tip of needle 110 against the surface of the eyeglass lens by an elastic force corresponding to the contraction of spring 132. In this way, when the worker brings four wheels 240 into contact with the surface of the eyeglass lens, pressing mechanism 120 presses the needle with a constant load against the surface of the eyeglass lens with four wheels 240 in contact with the surface of the eyeglass lens (step S102).

[0035] The operator moves the scratch tester 1 with the four wheels 240 in contact with the surface of the eyeglass lens (step S103). For example, the operator rolls the four wheels 240 on the surface of the eyeglass lens with the four wheels 240 in contact with the surface of the eyeglass lens. This moves the scratch tester 1 in the traveling direction, and the scratch tester 1 can scratch the surface of the eyeglass lens with the needles 110.

[0036] Here, when the scratch tester 1 scratches the surface of the eyeglass lens with the needle 110, the four wheels 240 are always in contact with the surface of the eyeglass lens. Therefore, if an operator moves the scratch tester 1 while the needle 110 is in contact with the surface of the eyeglass lens, the tip of the needle 110 can always be brought into contact with the surface of the eyeglass lens at a constant angle, allowing for a stable scratch test. As a result, the scratch tester 1 can scratch the curved lens surface with a constant load and angle, allowing for a stable evaluation of the scratch resistance of the coating.

[0037] (Variation 1) While the support unit 200 described above supports the pressing mechanism 120 while contacting the evaluation target surface at four locations, this is not limiting. For example, the support unit 200 may contact the evaluation target surface at three locations, or at five or more locations. FIG. 8 is a diagram showing Variation 1 of the scratch tester 1 according to this embodiment. As an example, as illustrated in FIG. 8, the support unit 200A of Variation 1 may have a traveling carriage 220 to which only three wheels 240 are attached. In this case, the needle 110 may be positioned within an area H2 formed by a straight line connecting the centers of the three wheels in a plan view, and more preferably, positioned at the center of the area H2.

[0038] (Variation 2) While the support unit 200 described above supports the pressing mechanism 120 in the vertical direction, this is not limiting. For example, the support unit 200 may support the pressing mechanism 120 in a state tilted at a predetermined angle θ from the vertical in the traveling direction or in the opposite direction to the traveling direction. FIG. 9 is a diagram showing Variation 2 of the scratch tester 1 according to this embodiment. As shown in FIG. 9, the support unit 200B of Variation 2 includes a fixing unit 210, a traveling carriage 220, and a locking mechanism 330. The fixing unit 210 is rotatable upward relative to the traveling platform 230. The locking mechanism 330 can fix the fixing unit 210 at any rotational position.

[0039] The locking mechanism 330 can fix the fixed part 210 at a desired rotation position from among a plurality of predetermined rotation positions, for example. As an example, the locking mechanism 330 includes a locking tooth provided on the rotation axis of the fixed part 210 and a plurality of recesses provided in the running platform 230. The locking mechanism 330 can fix the fixed part 210 at any rotation position by fitting the locking tooth into one of the plurality of recesses. Note that the locking mechanism 330 is not particularly limited in its fixing method as long as it can fix the fixed part 210 at any rotation position.

[0040] The scratch tester 1 of Modification 2 can support the pressing mechanism 120 in the vertical direction by fixing the predetermined angle θ at 0° using the locking mechanism 330. That is, the scratch tester 1 of Modification 2 can support the pressing mechanism 120 not only in the vertical direction but also in a state tilted from the vertical direction by the predetermined angle θ toward the traveling direction. However, this is not limited to this, and the scratch tester 1 may be configured to be able to support the pressing mechanism 120 only in a state tilted from the vertical direction by the predetermined angle θ toward the traveling direction or in the opposite direction to the traveling direction. The configuration of Modification 2 can also be applied to the configuration of Modification 1.

[0041] (Variation 3) While the support unit 200 described above supports the pressing mechanism 120 in the vertical direction, this is not limiting. For example, the support unit 200 may support the pressing mechanism 120 in a state tilted at a predetermined angle θ from the vertical in the traveling direction or in the opposite direction to the traveling direction. FIG. 10 is a diagram showing Variation 3 of the scratch tester 1 according to this embodiment. As shown in FIG. 10 , the support unit 200C of Variation 3 includes a fixed unit 210, a traveling carriage 220, and a spacer 340. The fixed unit 210 is rotatable upward relative to the traveling platform 230. The spacer 340 is inserted between the fixed unit 210 and the traveling platform 230 to ensure a constant gap between the fixed unit 210 and the traveling platform 230. This allows the fixed unit 210 to be fixed at a predetermined rotational position. The configuration of Variation 3 can also be applied to the configuration of Variation 1.

[0042] (Variation 4) While the support unit 200 described above supports the pressing mechanism 120 in the vertical direction, this is not limiting. For example, the support unit 200 may support the pressing mechanism 120 in a state tilted at a predetermined angle θ from the vertical in the traveling direction or in the opposite direction to the traveling direction. FIG. 11 is a diagram showing Variation 4 of the scratch tester 1 according to this embodiment. As shown in FIG. 11 , the support unit 200D of Variation 4 includes a fixed unit 210, a traveling carriage 220, and a locking mechanism 500. The locking mechanism 500 is provided on the fixed unit 210 and includes a mechanism for maintaining the orientation of the pressing mechanism 120 relative to the fixed unit 210. The locking mechanism 500 includes, for example, a fixing screw.

[0043] The fixing screw is inserted into the fixing portion 210. An operator can maintain the posture of the pressing mechanism 120 inserted into the fixing portion 210 by rotating and tightening the fixing screw. Therefore, when the operator wants to maintain the pressing mechanism 120 in a state inclined at a predetermined angle θ from the vertical direction in the traveling direction or in the direction opposite to the traveling direction, the operator manually adjusts the pressing mechanism 120 so that it is inclined at the predetermined angle θ, and after the adjustment, rotates and tightens the fixing screw to maintain the pressing mechanism 120 in a state inclined at the predetermined angle θ.

[0044] The scratch tester 1 of Modification 4 can support the pressing mechanism 120 in the vertical direction by fixing the predetermined angle θ at 0° using the locking mechanism 500. In other words, the scratch tester 1 of Modification 4 can support the pressing mechanism 120 not only in the vertical direction but also in a state tilted from the vertical direction by the predetermined angle θ toward the traveling direction. The configuration of Modification 4 can also be applied to the configuration of Modification 1.

[0045] As described above, the scratch tester 1 according to this embodiment is a tester that presses the needle 110 against the surface to be evaluated to scratch it, and includes a pressing mechanism 120 and a support unit (e.g., support units 200, 200A, 200B, 200C, and 200D). The pressing mechanism 120 has a needle attached to its lower end and presses the needle 110 against the surface to be evaluated with a constant load. The support unit 200 supports the pressing mechanism while it is in contact with the surface to be evaluated at three or more points. With this configuration, even if the surface to be evaluated is curved, the needle can be brought into contact with the surface to be evaluated at a constant angle, allowing for stable evaluation of the scratch resistance of the coating.

[0046] The execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings, is not specifically stated as "before," "prior to," or the like. It should also be noted that the execution order of each process can be realized in any order, as long as the output of a previous process is not used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," or the like for convenience, this does not mean that it is necessary to perform the process in this order. Furthermore, to the extent permitted by law, the disclosures of all documents cited in Japanese Patent Application No. 2024-100072 and the embodiments, etc., are incorporated by reference and constitute part of this specification.

[0047] 1... scratch tester, 100... scratch needle unit, 110... needle, 120... pressing mechanism, 200... support part, 240... wheel

Claims

1. A scratch tester that presses a needle against the surface of an object to be evaluated to scratch it, comprising: a pressing mechanism to which the needle is attached at the bottom end and which presses the needle against the surface with a constant load; and a support part that supports the pressing mechanism, wherein the support part supports the pressing mechanism while contacting the surface at three or more points.

2. A scratch tester as described in claim 1, wherein the support section is provided with a running body that can run on the surface while contacting the surface at three or more points, the running body having three or more wheels, and each of the wheels is in contact with the surface with the needle pressed against the surface.

3. The scratch tester according to claim 2, wherein, in a plan view, the needles are arranged within an area formed by connecting the centers of three or more of the wheels with straight lines.

4. The scratch tester according to claim 2, wherein the running body has four of the wheels, and in plan view, the needle is positioned at the center of an area formed by connecting the centers of the four wheels with a straight line.

5. The scratch tester according to claim 2, wherein the support section supports the pressing mechanism in the vertical direction.

6. A scratch tester according to claim 2, wherein the support section supports the pressing mechanism in a state inclined at a predetermined angle from the vertical direction toward the traveling direction of the traveling body.

7. A scratch test method using a scratch tester that presses a needle against a surface to be evaluated to scratch it, wherein the scratch tester has three or more wheels that can run on the surface, and the scratch test method includes: pressing the needle against the surface with a constant load while all of the wheels are in contact with the surface; and moving the scratch tester using the wheels while pressing the needle against the surface with the constant load.

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