Coating film cutting apparatus

Abstract

Provided is a coating film cutting apparatus that realizes a cutting process exposing a large amount of a base material, and that can subject a coating film to a cutting process for making uniform cuts with high reproducibility and stability. The apparatus is for performing a cutting process on a test piece TP on which a coating film is formed, and comprises a test piece holder 2 that holds the test piece TP, and a tool unit 3 that performs the cutting process. The test piece holder 2 is provided on an apparatus base 20 so as to be movable in the X-axis, Y-axis, and θ-axis directions. The tool unit 3 is attached to a second stage 73 suspended via a load cell from a first stage 71 that is provided to be movable in the Z-axis direction. The cutting process for the coating film is performed by attaching a hand-held cutting device 40 having a power source to the tool unit 3, moving the cutting device 40 in the Z-axis direction to cut the coating film, and moving the test piece holder 2 in the X-axis, Y-axis and θ-axis directions to make cuts of a desired depth, length, and direction.

Description

Coating film cutting device

[0001] The present invention relates to a coating film cutting device, and more particularly to a device for performing a predetermined cutting process on a test piece having a coating film formed on a substrate.

[0002] There are various general testing methods for paints, including tests that involve making a specified cut in the paint film. Examples include the cross-cut method (JIS-K5600-5-6) for evaluating the adhesion of paint films, the cyclic corrosion test method (JIS-K5600-7-9) for evaluating the long-term durability of paint films, the salt spray test method (JIS-Z2371), the outdoor exposure weather resistance test method (JIS-K5600-7-6), and Paint and varnishes - Corrosion Protection of steel structures by protective paint systems (ISO12944).

[0003] In such tests, test specimens having a coating film formed on a substrate are used. Predetermined incisions are made in the coating film of the test specimen with a cutter knife before or during the test. For example, in the cross-cut method, a rectangular grid pattern (25 squares) is manually cut into the coating film of the test specimen with a cutter knife as preparation before the test (see, for example, Patent Document 1). Furthermore, in cyclic corrosion tests and outdoor weathering tests, the incisions are manually made in the coating film of the test specimen with a cutter knife before the test, and then the test specimen is subjected to repeated corrosion cycles of salt spray, dry, and wet, or the outdoor weathering test is performed.

[0004] JP 2012-85725 A

[0005] However, such conventional methods have the following problems, and improvements are desired.

[0006] That is, when conventionally cutting into a coating film with a cutter knife, the amount of substrate exposed by the cutting tends to be small. As a result, in tests for coating durability, such as cyclic corrosion tests, salt spray tests, and outdoor exposure weathering tests, it takes a long time for the occurrence of rust due to corrosion of the substrate, swelling of the coating film, or peeling of the coating film to occur, resulting in the problem of long test times. Furthermore, while the depth and angle of the cut into the coating film, as well as the degree of penetration into the substrate, significantly affect the test results, conventional manual cutting processes result in poor reproducibility and stability of the cuts due to artificial bias, making it difficult to make uniform cuts in the coating film.

[0007] The present invention has been made in consideration of these problems, and its purpose is to provide a coating film cutting device that can realize cutting processing that exposes a large amount of the base material and can perform uniform cutting processing on the coating film with high reproducibility and stability.

[0008] In order to achieve the above-mentioned object, the coating film cutting device of the present invention is a device that performs a predetermined cutting process on a test piece having a coating film formed on its surface, and comprises a test piece holder that holds the test piece, and a tool unit equipped with a tool that performs the predetermined cutting process on the test piece held in the test piece holder, wherein the test piece holder is provided on an apparatus base so as to be movable in the X-axis, Y-axis and θ-axis directions, and the tool unit has a handheld cutting device having a power source and a tool holding section that detachably holds the cutting device, and the tool holding section is attached to a second stage that is suspended via a load cell from a first stage that is provided on the apparatus base so as to be movable in the Z-axis direction.

[0009] The present invention has the following features as preferred embodiments: (1) The cutting device has a linear device main body and a cutting tool detachably attached to the tip of the device main body, and the tool holder has a structure that holds the cutting device in an upright position along the Z-axis direction.

[0010] (2) The tool holding unit is characterized by having a tip-side fixing portion that fixes the tip side of the cutting device, and a base-side fixing portion that is located on the base-side side of the tip-side fixing portion and fixes the device main body portion of the cutting device.

[0011] (3) The tip-side fixing portion has a support hole that penetrates in the Z-axis direction, and is characterized by having a structure in which the tip side of the cutting device is inserted into and supported by this support hole.

[0012] (4) The cutting device is characterized by being composed of an electric micro-grinder.

[0013] (5) The tool unit is characterized in that it has a suction port of a suction mechanism for sucking chips generated during cutting at a position facing the cutting tool.

[0014] (6) The suction mechanism has a suction passage communicating with a suction device and a suction nozzle communicating with the suction passage, and the suction nozzle has a cylindrical portion surrounding the outer periphery of the cutting tool near its tip, and the annular opening formed on the outer periphery of the cutting tool by this cylindrical portion serves as the suction port.

[0015] (7) The test piece holder is characterized by having a lifting stage that can be raised and lowered in the Z-axis direction, a holding frame that cooperates with the lifting stage to clamp and hold the periphery of the test piece, and a chip prevention tray that catches chips that spill outside the holding frame.

[0016] (8) The device base is characterized by comprising an X-axis drive mechanism for driving the test piece holder in the X-axis direction, a Y-axis drive mechanism for driving the test piece holder in the Y-axis direction, a θ-axis drive mechanism for driving the test piece holder to rotate around the θ-axis, a Z-axis drive mechanism for driving the first stage in the Z-axis direction, and a control means for driving and controlling each of these drive mechanisms.

[0017] According to the present invention, a test piece holder for holding a test piece having a coating formed thereon is configured to be movable in the X-axis, Y-axis, and θ-axis directions on an apparatus base, and a tool unit for cutting into the coating is mounted on a second stage suspended via a load cell from a first stage movable in the Z-axis direction on the apparatus base. For example, the tool unit, with the cutting tool not rotating, can be lowered to the position of the test piece, and the position where a specified load value is detected on the load cell can be set as the origin of the Z-axis. From there, the cutting tool can be rotated to lower the test piece to a specified cutting depth, and while maintaining the specified depth, the test piece can be moved in the X-axis or other direction to cut the coating of the test piece, thereby achieving highly reproducible, stable, and uniform cutting into the coating. Therefore, the coating cutting device of the present invention allows tests to be performed accurately and without variation to evaluate the mechanical properties of coatings.

[0018] The tool unit is also equipped with a handheld cutting device with a power source. For example, by using an end mill as the cutting tool for the cutting device, it is possible to form a large incision in the coating of a test piece, equivalent to the diameter of the attached end mill, so that the substrate is exposed. As a result, in coating durability tests, the time until rust due to corrosion of the substrate, swelling of the coating, peeling of the coating, etc., occurs can be shortened, thereby shortening the time required for testing. Furthermore, the coating and substrate can be cut with a consistent width and depth, allowing for a uniform incision treatment to be performed on the coating with high reproducibility and stability, thereby obtaining consistent results in coating durability tests such as cyclic corrosion tests, salt spray tests, and outdoor exposure weathering tests.

[0019] 7(a) and 7(b) are perspective views showing an example of the external configuration of a paint film cutting device according to the present invention; FIG. 7(a) is a perspective view showing an example of the external configuration of the paint film cutting device according to the present invention; FIG. 7(b) is a perspective view showing an example of the external configuration of a tool unit of the paint film cutting device according to the present invention; FIG. 7(b) is a perspective view showing an example of the external configuration of a test piece holder of a paint film cutting device according to the present invention; FIG. 7(a) shows a state in which the lifting stage is raised to hold a test piece, and FIG. 7(b) shows a state in which the lifting stage is lowered to remove the test piece; and FIG. 7(b) is a partial cross-sectional view of the tool unit and test piece holder showing the state in which the test piece is cut by the paint film cutting device.

[0020] Hereinafter, an embodiment of a coating film cutting device according to the present invention will be described in detail with reference to the drawings. In this specification and the drawings, components having substantially the same functional configurations will be designated by the same reference numerals and redundant description will be omitted.

[0021] The coating film cutting device 1 is a device for performing a predetermined cutting process on a test piece TP having a coating film formed on its surface, and its main parts include a test piece holder 2 that holds the test piece TP, and a tool unit 3 that holds a tool (cutting device 40) that performs the predetermined cutting process on the test piece TP.

[0022] Here, the test piece TP is a plate- or film-shaped sample having a coating film, the mechanical properties of which are to be evaluated, formed on a substrate made of metal, resin, or the like. Examples of the substrate include metals (iron, carbon steel, weathering steel, zinc, copper, aluminum, stainless steel, etc.), synthetic resins such as plastic, as well as concrete, rubber, and glass. Examples of the coating film include coating films formed by applying or printing paint (acrylic resin-based, silicone resin-based, fluororesin-based paint, etc.). In this embodiment, the test piece TP is exemplified by a test piece TP formed by forming a coating film on a thin metal plate, as shown in FIG. 8 . However, it is also possible to use a test piece TP formed by forming a coating film on a thick substrate (e.g., a concrete piece), as shown in FIG. 7( a).

[0023] As shown in FIGS. 1 and 2 , the coating film cutting device 1 is housed in a casing 4. The casing 4 is composed of a casing main body 4a that covers the entire device and an openable / closable lid 4b that is attached to the casing main body 4a via a hinge 5 so that the entire device, including the test piece holder 2 and the tool unit 3, can be housed in a closed space by closing the openable / closable lid 4b. Therefore, when performing the cutting process on the test piece TP, closing the openable / closable lid 4b can prevent chips such as coating chips from scattering outside the device. In this embodiment, the casing 4 is formed by assembling aluminum frames 4c, 4c, ... in a three-dimensional (box-like) shape, and a predetermined panel is attached within the frame 4c to form a closed space. The reference symbol 4d in the figures indicates a transparent window panel provided on the frame 4c that constitutes the openable / closable lid 4b. The cutting process status can be viewed from outside the casing 4 through this window panel 4d. Also, reference numeral 4e in the drawing denotes a metallic decorative panel provided on the frame 4c that constitutes the casing body 4a.

[0024] The test piece holder 2 is a holder for fixedly holding the test piece TP, and as shown in Figures 7 and 8, is composed mainly of a lifting stage 6 that is configured to be able to move up and down in the vertical direction (Z-axis direction), a pressure frame 7 that cooperates with the lifting stage 6 to clamp and hold the test piece TP, and a chip prevention tray 17 that catches chips that spill out of the pressure frame 7.

[0025] Specifically, the test piece holder 2 includes a base plate 8, support columns 9 erected on the base plate 8, a pressure frame 7 arranged on the support columns 9, a lifting stage 6 arranged below the pressure frame 7, and a lifting mechanism 10 for the lifting stage 6. The base plate 8 is composed of a substantially rectangular plate-like member, with support columns 9 erected at its four corners. The pressure frame 7 is a member that abuts against the outer edge of the test piece TP when the lifting stage 6 on which the test piece TP is placed is raised, sandwiching and holding the test piece TP between itself and the lifting stage 6. The pressure frame 7 is composed of a frame with an opening in the center, and its four corners are attached to the support columns 9. An elastic body (e.g., a rubber plate) (not shown) is arranged on the surface (underside) of the pressure frame 7 that faces the lifting stage 6. This prevents the test piece TP from shifting out of position due to friction with the elastic body. Furthermore, in this type of test piece TP, a large amount of paint that forms a coating film may be applied to the outer periphery of the test piece TP in order to seal the end of the test piece TP, which may cause the outer periphery of the test piece TP to bulge. However, even if the outer periphery of the test piece TP is bulged in this way, by placing an elastic body on the holding frame 7, the test piece TP can be securely held.

[0026] The lifting stage 6 is composed of a substantially rectangular plate-like member arranged inside the four support columns 9, 9, .... The lifting mechanism 10 includes a cam 18 acting on the underside of the lifting stage 6, a lifting knob 11 connected to the cam's rotation shaft 19, and a linear shaft 12 and linear bushing 13 that guide the lifting stage 6's vertical movement. Rotation of the lifting knob 11 rotates the rotation shaft 19, causing the cam 18 to act on the lifting stage 6 and raise or lower it. Reference numeral 14 in the figure denotes a rotation stopper that limits the rotation of the lifting knob 11 when the lifting stage 6 is fully lowered. The lifting stage 6 shown in Figure 7 also has a groove 16 formed on its outer periphery that is lower than the center. This groove 16 is for accommodating the bulging outer peripheral portion of the test piece TP with the bulging outer peripheral edge described above. By accommodating the outer peripheral edge in this groove, the test piece TP can be stably placed on the lifting stage 6.

[0027] The chip drop prevention tray 17 is a member for preventing chips generated during the cutting process of the test piece TP from falling toward the apparatus base 20 (described later), and is disposed below the lift stage 6. In this embodiment, the chip drop prevention tray 17 is configured as a dish-shaped member having a substantially rectangular shape similar to the lift stage 6 and the presser frame 7, and its outer periphery protrudes outward beyond the outer peripheries of the lift stage 6 and the presser frame 7. The chip drop prevention tray 17 is also attached to the underside of the lift stage 6 so that it can move up and down together with the lift stage 6. This prevents chips (such as cutting chips of the coating or base material) generated during the cutting process of the test piece TP from spilling outward from the presser frame 7 and falling below the test piece holder 2 (specifically, onto the XY stage 29 or base plate 21 (described later)).

[0028] When using the test strip holder 2 configured as described above, first, the lifting stage 6 is lowered to the test strip TP setting position, and the test strip TP is placed on the lifting stage 6 at that position. If the test strip TP is thin, spacers SP for adjusting the height position of the surface of the test strip TP are appropriately placed below the test strip TP, as shown in FIG. 8 (FIG. 8 shows a state in which two spacers SP are placed). Once the test strip TP has been placed, the lifting knob 11 is then operated to lift the lifting stage 6. By lifting the lifting stage 6, the test strip TP is sandwiched between the lifting stage 6 and the retainer frame 7, and the test strip TP is held between the lifting stage 6 and the retainer frame 7.

[0029] In the coating film cutting device 1 of the present invention, the test piece holder 2 having such a configuration is provided on the device base 20 of the coating film cutting device 1 so as to be movable in the X-axis direction (left-right direction), Y-axis direction (front-back direction), and θ-axis direction (circumferential direction).

[0030] The device base 20 of the paint film cutting device 1 will now be described with reference to Figure 3. In the paint film cutting device 1 shown in this embodiment, an electrical component area EA is formed on the underside of a base plate 21 that constitutes the device base 20, and houses electrical components such as a display unit 90, an operation unit 91, a microcomputer (not shown), and a power supply unit, while a test piece holder area HA is formed on the upper side of the base plate 21, and houses a test piece holder 2 and its drive mechanism, and above that a tool unit area TA is formed, and houses a tool unit 3 and its drive mechanism.

[0031] The test specimen holder 2 is disposed on a base plate 21. The base plate 21 is supported at a predetermined height within the casing 4 by a frame structure made up of frames 4c, 4c, ... of the casing 4, and an electrical equipment area EA is formed between the base plate 21 and a bottom plate (not shown) of the casing 4. The base plate 21 is provided with a Y-axis drive mechanism 25 that moves the test specimen holder 2 in the Y-axis direction, an X-axis drive mechanism 26 that moves the test specimen holder 2 in the X-axis direction, and a θ-axis drive mechanism 27 that rotates the test specimen holder 2 around the θ-axis.

[0032] The Y-axis drive mechanism 25 includes a pair of Y-axis rails 28 arranged in the Y-axis direction on the base plate 21, an XY stage 29 arranged so as to be able to move in the Y-axis direction on the Y-axis rails 28, and a Y-axis motor (not shown) that drives the XY stage 29 in the Y-axis direction. The Y-axis motor is connected to a control unit 100 (described later), and the control unit 100 can control the position of the XY stage 29 in the Y-axis direction.

[0033] The X-axis drive mechanism 26 includes a pair of X-axis rails 31 disposed in the X-axis direction on the XY stage 29, a first θ stage 32 disposed on the X-axis rails 31 so as to be movable in the X-axis direction, and an X-axis motor 33 that drives the first θ stage 32 in the X-axis direction. The X-axis motor 33 is connected to a control unit 100 (described later) so that the position of the first θ stage 32 in the X-axis direction can be controlled by the control unit 100. Support columns 38 are erected at the four corners of the first θ stage 32, and a second θ stage 34 is disposed on these support columns 38. In other words, the θ stage disposed on the X-axis rails 31 has a two-layer structure consisting of a first and second θ stage.

[0034] The θ-axis drive mechanism 27 includes an annular θ-axis rail (not shown) disposed on the second θ-stage 34, a test specimen holder mounting plate 36 disposed on the θ-axis rail and rotatable about the θ-axis, and a θ-axis motor (not shown) that rotates a θ-axis body (not shown) connected to the test specimen holder mounting plate 36. The θ-axis motor is connected to a control unit 100 (described later) so that the rotation angle of the test specimen holder mounting plate 36 can be controlled by the control unit 100. The θ-axis body is connected to an electromagnetic brake (not shown) disposed on the first θ-stage 32, penetrating the second θ-stage 34, so that the rotation of the θ-axis body can be stopped by the electromagnetic brake. This prevents and fixes the rotation of the test specimen holder 2 attached to the test specimen holder mounting plate 36, preventing misalignment of the test specimen holder 2 during the cutting process of the test specimen TP.

[0035] The base plate 8 of the test specimen holder 2 is attached to the test specimen holder mounting plate 36 of the θ-axis drive mechanism 27. As a result, the test specimen holder 2 is rotated together with the rotation of the test specimen holder mounting plate 36.

[0036] In this embodiment, the Y-axis drive mechanism 25, the X-axis drive mechanism 26, and the θ-axis drive mechanism 27 of the test piece holder 2 are configured in a stacked structure in which their height positions in the vertical direction are offset. This allows the drive means of the test piece holder 2 to be placed in a narrow space (a narrow space when viewed from above), and the coating film cutting device 1 can be configured compactly.

[0037] On the other hand, the tool unit 3 is a unit for performing a predetermined cutting process on the test piece TP held by the test piece holder 2, and as shown in Figures 4 to 6, it mainly comprises a cutting device 40 for performing the cutting process on the test piece TP and a tool holding part 50 for detachably holding the cutting device 40. In this embodiment, the tool unit 3 is also provided with a suction mechanism 60 for sucking up chips generated during the cutting process.

[0038] The cutting device 40 is a handheld cutting device having a power source. The cutting device 40 includes a linear (so-called pencil-shaped) device main body 41 shaped to be held in one hand, and a cutting tool 42 detachably attached to the tip of the device main body 41. In this embodiment, the cutting device 40 is configured as an electric device equipped with an electric motor (not shown) as a power source. The cutting device 40 includes an electric motor in the device main body 41 that rotates the cutting tool 42, and the electric motor is wired to a motor control device (not shown) located outside the casing 4 via a control cable 43. The motor control device supplies power to the electric motor and controls its drive. The motor control device receives power from an external commercial power source (not shown) and supplies it to the electric motor. The motor control device also controls the ON / OFF and rotation speed of the electric motor built into the device main body 41.

[0039] The tip of the device main body 41 is provided with a chucking mechanism 44 to which a cutting tool 42 can be detachably attached. The chucking mechanism 44 is configured so that the cutting tool 42 can be attached and detached manually. In this embodiment, an end mill is attached to the chucking mechanism 44 as a tool for cutting into the coating film of the test piece TP. Cutting into the coating film using an end mill can form wider cuts in the coating film than cutting into the coating film using a cutter knife. In this embodiment, an end mill is preferably used as the cutting tool 42, but tools other than an end mill, such as a slot drill or cobalt slot drill, can also be used as long as they are capable of making wider cuts in the coating film in conjunction with the rotation of the electric motor.

[0040] In this embodiment, a commercially available micro grinder (for example, EV410-100 / EV410-230 manufactured by Nakanishi Corporation) is used as the cutting device 40. By using a commercially available device as the cutting device 40 in this manner, the manufacturing costs and maintenance costs of the tool unit 3 can be kept low.

[0041] The tool holding unit 50 detachably holds the cutting device 40 and has a structure for holding the cutting device 40 in an upright state along the Z-axis direction. Specifically, the tool holding unit 50 has a tip-side fixing part 51 that fixes the tip side of the cutting device 40, a base-side fixing part 52 that is located on the base-side side of the tip-side fixing part 51 and fixes the device main body part 41 of the cutting device 40, and a connecting part 53 that connects the tip-side fixing part 51 and the base-side fixing part 52.

[0042] The distal end fixing portion 51 is composed of a horizontally disposed, substantially rectangular, plate-like member. One longitudinal end of this plate-like member is fixed to the lower end of the connecting portion 53, and a support hole 54 penetrating in the Z-axis direction is formed on the other longitudinal end side. The support hole 54 is a hole for inserting the distal end of the cutting device 40. As shown in FIG. 6 , by inserting the distal end of the cutting device 40 into the support hole 54, the distal end of the cutting device 40 is positioned and supported by the periphery of the support hole 54. That is, the distal end fixing portion 51 is configured to support the distal end of the cutting device 40 by utilizing a portion of the cutting device 40 whose body diameter increases from the distal end to the proximal end and receiving the cutting device 40 using the support hole 54, which has an opening diameter narrower than this increased body diameter. Therefore, the cutting device 40, whose distal end is supported by the support hole 54, stably holds the cutting tool 42 provided at its tip without wobbling in the front-to-back, left-to-right (X-axis and Y-axis) directions.

[0043] The proximal fixing portion 52 has a structure for sandwiching and fixing the device body 41 of the cutting device 40. The proximal fixing portion 52 includes a body 55 fixed to the connecting portion 53 and a pressing piece 56 for pressing and fixing the cutting device 40 against the body 55. The body 55 is a block-shaped member having a thickness in the Z-axis direction. One longitudinal end of the body 55 is fixed to the upper end of the connecting portion 53, and a mounting groove 58 penetrating in the Z-axis direction is formed in the end face of the other longitudinal end (see FIG. 5 ). The mounting groove 58 is a concave groove corresponding to the outer circumferential shape of the device body 41 of the cutting device 40. The pressing piece 56 has a second mounting groove 59 penetrating in the Z-axis direction in the end face facing the body 55 (see FIG. 5 ). Like the mounting groove 58, the second mounting groove 59 is also a concave groove corresponding to the outer circumferential shape of the device body 41 of the cutting device 40. Then, by abutting the pressing piece 56 against the end face on the other end side of the main body 55, a holding space for the cutting device 40 is formed between the second mounting groove 59 and the mounting groove 58, and the device main body 41 of the cutting device 40 is sandwiched and held in this holding space. The pressing piece 56 is detachably attached to the main body 55 with a screw 57, whereby the device main body 41 of the cutting device 40 is detachably fixed to the main body 55.

[0044] To use the tool holder 50 configured as described above, the distal end of the cutting device 40 is first inserted into the support hole 54 of the distal fixation part 51 to position the distal end of the cutting device 40. The device body 41 of the cutting device 40 is then sandwiched between the mounting groove 58 and the second mounting groove 59 of the proximal fixation part 52, and the presser piece 56 is then attached and fixed to the body 55. This holds the cutting device 40 in an upright position along the Z-axis with the cutting tool 42 facing downward. The entire circumference of the cutting device 40 is sandwiched between the two surfaces formed by the mounting groove 58 and the second mounting groove 59 of the proximal fixation part 52, stably holding the device body 41. This suppresses wobbling of the cutting device 40 due to cutting resistance and load during cutting into the test piece TP, enabling stable cutting.

[0045] The suction mechanism 60 is a device for sucking and removing chips generated during cutting processing by the cutting device 40, and its main parts include a suction device 61 (not shown), a suction passage 62 connected to the suction device 61, and a suction nozzle 63 connected to the suction passage 62.

[0046] The suction device 61 is a device for sucking chips, such as chips from the coating and substrate of the test piece TP, and is disposed outside the casing 4 in this embodiment. A commercial or household vacuum cleaner, for example, is preferably used as the suction device 61. The suction nozzle 63 is a component that provides a chip suction port 64 facing the cutting tool 42 (see FIG. 6 ). In this embodiment, the suction nozzle 63 is disposed on the underside of the tip-side fixed portion 51 of the tool holder 50. The suction nozzle 63 has a cylindrical portion 63a that surrounds the outer periphery of the cutting tool 42 near its tip. The cylindrical portion 63a forms an annular opening on the outer periphery of the cutting tool 42, forming the suction port 64. By configuring the suction port 64 in this annular shape, the suction port 64 is formed around the cutting tool 42, allowing for efficient chip suction. When forming the suction port 64, the tip of the cutting tool 42 is configured to protrude from the lower end surface of the suction nozzle 63, as shown in FIG. 6 . This is to prevent the lower end face of the suction nozzle 63 from contacting and interfering with the surface of the test piece TP during cutting processing by the cutting tool 42. For example, if the cutting depth into the test piece TP is 2 mm, the protrusion amount L1 of the cutting tool 42 is set to a value (e.g., 3 mm) longer than the cutting depth.

[0047] Furthermore, a pipe joint 65 is attached to the cylindrical portion 63a, one end of which penetrates the side wall of the cylindrical portion 63a. One end of a flexible suction tube 66 is attached to the other end of the pipe joint 65. The flexible suction tube 66 is a tube having flexibility that allows it to accommodate the lifting and lowering movement of the tool unit 3, which will be described later, and the other end is connected to one end of a suction pipe line 67. The suction pipe line 67 is a pipe for connecting the other end of the flexible suction tube 66 to a suction port (not shown) of the suction device 61. As shown in FIGS. 2 and 3 , the other end is drawn out of the casing 4 and ultimately connected to the suction port of the suction device 61. That is, the suction device 61 and the suction nozzle 63 are connected to communicate with each other via the suction pipe line 67, the flexible suction tube 66, and the pipe joint 65, which together form a chip suction passage 62.

[0048] The tool unit 3 configured in this manner is provided with a mounting plate 35 on the back side of the connecting portion 53 of the tool holding portion 50 (the surface opposite to the surface on which the tip-end fixing portion 51 and the base-end fixing portion 52 are provided) to support the tool unit 3 so that it can move in the Z-axis direction (up and down direction), and is detachably attached to the second stage 72 described later via this mounting plate 35.

[0049] Next, a description will be given of a structure that allows the tool unit 3 to move in the Z-axis direction. In the coating film cutting device 1 shown in this embodiment, the tool unit 3 is attached to a second stage 72 that is suspended via a load cell (not shown) from a first stage 71 that is provided on the device base 20 so as to be movable in the Z-axis direction, as shown in FIG.

[0050] The first stage 71 is attached to a Z-axis base plate 70 for movement along the Z axis, which is provided upright on the base plate 21. A pair of Z-axis rails 73 are arranged on the Z-axis base plate 70 in the Z-axis direction, and the first stage 71 is slidably mounted on these Z-axis rails 73. The Z-axis base plate 70 is also provided with a Z-axis drive mechanism (not shown) that drives the first stage 71 in the Z-axis direction. The Z-axis drive mechanism includes a Z-axis rail and a Z-axis motor (not shown) that drives the first stage 71 in the Z-axis direction. The first stage 71 is drivingly coupled to the Z-axis motor, thereby driving the first stage 71 in the Z-axis direction. The Z-axis motor is connected to a control unit 100 (described later), and the Z-axis positions of the first stage 71, and therefore the tool unit 3, can be controlled via the control unit 100.

[0051] The load cell is a sensor that measures the load applied to the tool unit 3, and has one end connected to the first stage 71 and the other end connected to the second stage 72. As a result, the second stage 72 is suspended from the first stage 71 via the load cell.

[0052] When the tool unit 3 is attached to the suspended second stage 72 in this manner, the weight of the tool unit 3 places the load cell in tension, causing the second stage 72 to descend. Assuming the tool unit 3 has a weight of 1 kg and the load cell deflection per 1 kg is 4 μm, if the first stage 71 is lowered in this state and the tip of the cutting tool 42 of the cutting device 40 held by the tool unit 3 comes into contact with the test piece TP, the load cell's deflection, which was in a tension state of 4 μm before contact, will gradually return. If the return amount at this time is 4 μm or less, this indicates that a load less than the tool unit's weight (1 kg) is being applied. If the first stage 71 is further lowered and a compressive deflection is applied to the load cell, this indicates that a load greater than the tool unit's weight is being applied. These loads are all set by the thrust of the Z-axis motor of the Z-axis drive mechanism. The load cell is connected to the control unit 100, which is capable of measuring the load applied to the tool unit 3.

[0053] The second stage 72 is a portion on which the tool unit 3 is attached and is made up of a substantially plate-shaped member. In this embodiment, the second stage 72 is attached to a pair of guide rails (not shown) arranged in the Z-axis direction on the surface of the first stage 71, and is configured to be able to slide in the Z-axis direction along the guide rails.

[0054] In this way, in the coating film cutting device 1 shown in this embodiment, by moving the first stage 71 in the Z-axis direction, the tool unit 3 attached to the second stage 72 can be moved in the Z-axis direction, thereby enabling the cutting tool 42 of the cutting device 40 held in the tool unit 3 to be used to perform a predetermined cutting process on the test piece TP held in the test piece holder 2.

[0055] The control unit 100 is a control device that controls the Y-axis drive mechanism 25 (Y-axis motor), the X-axis drive mechanism 26 (X-axis motor 33), the θ-axis drive mechanism 27 (θ-axis motor), the Z-axis drive mechanism (Z-axis motor), etc., and in this embodiment is configured with a microcomputer (not shown) that has a control program that controls the drive of each of these drive mechanisms and the display of the display unit 90, and is housed in the electrical equipment area EA of the apparatus base 20. In particular, in this embodiment, the control unit 100 is configured to perform a cutting process on the coating film, which will be described later, through the drive control of each of these drive mechanisms.

[0056] Note that reference numeral 90 in the figure indicates a display unit of the paint film cutting device 1. In this embodiment, the display unit 90 is configured, for example, as a touch panel that also serves as an operation unit 91. Also, reference numeral 91 in the figure indicates an operation unit configured with physical switches other than a touch panel. A user of the paint film cutting device 1 can input various instructions to the control unit 100 by operating the physical switches or touch panel while checking the display on the display unit 90.

[0057] Next, a description will be given of the process of cutting into the coating film of the test piece TP by the coating film cutting device 1. The process of cutting into the coating film is generally carried out in the following procedure.

[0058] (1) Mounting of the test piece TP on the test piece holder 2 Before the coating film cutting process, as a preliminary preparation, the test piece TP on whose surface a coating film has been formed is mounted on the test piece holder 2. This mounting is performed by sandwiching and holding the test piece TP between the lifting stage 6 and the holding frame 7, as described above.

[0059] (2) Mounting the Cutting Device 40 on the Tool Unit 3 In parallel with mounting the test piece TP on the test piece holder 2, the cutting device 40 is mounted on the tool unit 3. This mounting is performed by removing the retaining piece 56 of the base-end fixing part 52. Specifically, with the retaining piece 56 removed, the tip of the cutting device 40 is inserted into the support hole 54 of the tip-end fixing part 51 to position the tip, while fitting the device body 41 of the cutting device 40 into the mounting groove 58 of the base-end fixing part 52, and then mounting the retaining piece 56 on top and fixing with screws, thereby completing the mounting of the cutting device 40. Note that this step can be omitted by using a tool unit 3 on which the cutting device 40 has already been mounted.

[0060] (3) Cutting Process: Once the cutting device 40 is installed, the test piece TP is then cut. The test piece TP may be cut manually by a user operating the Y-axis drive mechanism 25, X-axis drive mechanism 26, θ-axis drive mechanism 27, and Z-axis drive mechanism via the operation unit 91. However, in this embodiment, all or part of the cutting process is automatically performed by automatic control by the control unit 100. That is, the user inputs data necessary for automatic control of the cutting process of the test piece TP, and the control unit 100, based on the input data, drives and controls the Y-axis drive mechanism 25, X-axis drive mechanism 26, θ-axis drive mechanism 27, and Z-axis drive mechanism to automatically perform the cutting process. Note that in this embodiment, the cutting device 40 and suction device 61 are not linked to the control unit 100, and therefore these devices are manually operated by the user.

[0061] An example of a cutting process performed by the control unit 100 is described below. A: Cutting Process with Specified Load (I) In this cutting process, the control unit 100 first drives the Z-axis drive mechanism to lower the cutting tool 42. At this time, the cutting device 40 and the suction device 61 are inactive. (II) During the lowering of the cutting tool 42, the control unit 100 monitors the load detected by the load cell. When the detected load reaches a predetermined load (a load set by the user), the control unit 100 stops the lowering of the cutting tool 42. The user manually operates the cutting device 40 and the suction device 61 at this timing. (III) After stopping the lowering of the cutting tool 42, the control unit 100 appropriately drives and controls the Y-axis drive mechanism 25, the X-axis drive mechanism 26, and the θ-axis drive mechanism 27 based on previously input data while maintaining the Z-axis drive mechanism in a stopped state (the position of the first stage 71 in the Z-axis direction), thereby cutting the test piece TP with the cutting tool 42.

[0062] At this time, by driving the Y-axis drive mechanism 25 or the X-axis drive mechanism 26, the test piece TP can be cut in the Y-axis direction or the X-axis direction. Furthermore, by combining this with the lifting and lowering operation of the tool unit 3 by the Z-axis drive mechanism, multiple rows of cuts can be made in the test piece TP. Furthermore, by combining this with the rotation of the test piece holder 2 by the θ-axis drive mechanism 27, orthogonal cuts can be made in the test piece TP. Additionally, by controlling the Y-axis drive mechanism 25 and the X-axis drive mechanism 26, for example, the cutting speed can be kept constant.

[0063] B: Cutting Process with Specified Depth of Cut (I) In this cutting process, the control unit 100 first drives the Z-axis drive mechanism to lower the cutting tool 42. At this time, the cutting device 40 and the suction device 61 are in a stopped state. (II) While the cutting tool 42 is lowering, the control unit 100 monitors the load detected by the load cell. When the detected load reaches a predetermined load (a load set by the user), the control unit 100 stops the lowering of the cutting tool 42 and stores the Z-axis position at that time as the origin for measuring the depth of cut. The user manually operates the cutting device 40 and the suction device 61 at this timing. (III) The control unit 100 drives the Z-axis drive mechanism until the predetermined depth of cut (the depth of cut set by the user) is reached, based on the origin for measuring the depth of cut. At this point, the control unit 100 stops the Z-axis drive mechanism. Then, while maintaining this stopped state (the position of the first stage 71 in the Z-axis direction), the Y-axis drive mechanism 25, the X-axis drive mechanism 26, and the θ-axis drive mechanism 27 are appropriately driven and controlled based on the data input in advance, and the cutting tool 42 makes a cut into the test piece TP.

[0064] In addition, in the coating film cutting device 1 according to this embodiment, chips generated during such cutting processing are sucked up by the suction device 61 and discharged and removed outside the device, and chips that fall from the test piece holder 2 are caught by the chip prevention tray 17, thereby effectively preventing the Y-axis drive mechanism 25, X-axis drive mechanism 26, θ-axis drive mechanism 27, etc. from malfunctioning due to chips that have fallen.

[0065] In this way, the coating film cutting device 1 according to the present invention can perform cutting processing by specifying the load and cutting depth acting on the test piece TP (coating), thereby making it possible to perform uniform cutting in the coating film with high reproducibility and stability. Therefore, by using the coating film cutting device 1 according to the present invention, tests to evaluate the mechanical properties of coating films can be performed accurately and without variation.

[0066] Furthermore, when cutting the test piece TP, an end mill or the like can be selected as the cutting tool 42 attached to the cutting device 40 of the tool unit 3, thereby making it possible to form cuts in the coating film of the test piece TP that expose a large amount of the substrate. As a result, the time until deterioration of the substrate or the like appears in a test regarding the durability of the coating film can be shortened, and the time required for the test can be reduced.

[0067] The above-described embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to these, and various design modifications are possible within the scope of the present invention.

[0068] For example, in the above-described embodiment, the lifting stage 6 of the test specimen holder 2 is manually raised and lowered, but it is also possible to configure the lifting stage 6 to be raised and lowered electrically, for example by arranging an electric motor in the test specimen holder 2.

[0069] In addition, in the above-described embodiment, an electric cutting device driven by an external power source is used as the cutting device 40, but it is also possible to use a battery-powered cutting device driven by an internal power source, or to use a cutting device that uses a power source other than electricity, such as an air motor that uses compressed air.

[0070] Furthermore, in the above-described embodiment, the tool holding unit 50 holds the cutting device 40 using two fixing parts, the distal fixing part 51 and the proximal fixing part 52, but the cutting device 40 may be held using a single fixing part or three or more fixing parts. Furthermore, the individual fixing parts constituting the tool holding unit 50 may have any structure as long as they can detachably hold the cutting device 40, and are not limited to the structure shown in the above-described embodiment, and the design can be modified as appropriate.

[0071] In addition, in the above-described embodiment, the suction device 61 of the suction mechanism 60 is disposed outside the casing 4, but the suction device 61 may be housed inside the casing 4. Furthermore, the suction port 64 of the suction nozzle 63 may have any configuration as long as it is capable of suctioning chips generated by the cutting process, and the specific shape and arrangement may be changed as appropriate.

[0072] DESCRIPTION OF SYMBOLS 1 Coating film cutting device 2 Test piece holder 3 Tool unit 4 Casing 6 Lifting stage 7 Pressing frame 10 Lifting mechanism 17 Chip fall prevention tray 20 Device base 21 Base plate 25 Y-axis drive mechanism 26 X-axis drive mechanism 27 θ-axis drive mechanism 29 XY stage 32 First θ stage 34 Second θ stage 40 Cutting device 41 Device main body 42 Cutting tool 44 Chucking mechanism 50 Tool holding part 51 Tip-end side fixing part 52 Base-end side fixing part 53 Connection part 54 Support hole 60 Suction mechanism 61 Suction device 62 Suction passage 63 Suction nozzle 64 Suction port 71 First stage 72 Second stage 90 Display part 91 Operation part 100 Control part TP Test piece

Claims

1. A coating cutting device that performs a predetermined cutting process on a test piece having a coating film formed on its surface, comprising: a test piece holder that holds the test piece; and a tool unit equipped with a tool that performs the predetermined cutting process on the test piece held in the test piece holder, wherein the test piece holder is provided on an apparatus base so as to be movable in the X-axis, Y-axis and θ-axis directions, and the tool unit has a handheld cutting device with a power source and a tool holding section that detachably holds the cutting device, and the tool holding section is attached to a second stage that is suspended via a load cell from a first stage that is provided on the apparatus base so as to be movable in the Z-axis direction.

2. The coating film cutting device described in claim 1, characterized in that the cutting device has a linear device main body and a cutting tool that is detachably attached to the tip of the device main body, and the tool holding part has a structure that holds the cutting device in an upright position along the Z-axis direction.

3. The coating cutting device described in claim 2, characterized in that the tool holding unit has a tip-side fixing unit that fixes the tip side of the cutting device, and a base-side fixing unit that is located on the base-side side of the tip-side fixing unit and fixes the device main body unit of the cutting device.

4. The coating film cutting device described in claim 3, characterized in that the tip side fixing portion has a support hole that penetrates in the Z-axis direction, and has a structure in which the tip side of the cutting device is inserted and supported in this support hole.

5. The coating film cutting device according to claim 4, wherein the cutting device is an electric micro-grinder.

6. A coating film cutting device as described in claim 2, characterized in that the tool unit has a suction port of a suction mechanism at a position facing the cutting tool for sucking up chips generated during cutting.

7. The coating film cutting device described in claim 6, characterized in that the suction mechanism comprises a suction passage communicating with a suction device and a suction nozzle communicating with the suction passage, the suction nozzle having a cylindrical portion surrounding the outer periphery of the cutting tool near its tip, and the annular opening formed on the outer periphery of the cutting tool by this cylindrical portion serves as the suction port.

8. The coating film cutting device described in claim 1, characterized in that the test piece holder has a lifting stage that can be raised and lowered in the Z-axis direction, a holding frame that cooperates with the lifting stage to clamp and hold the periphery of the test piece, and a chip prevention tray that catches chips that spill outside the holding frame.

9. A coating film cutting device as described in any one of claims 1 to 8, characterized in that the device base is equipped with an X-axis drive mechanism that drives the test piece holder in the X-axis direction, a Y-axis drive mechanism that drives the test piece holder in the Y-axis direction, a θ-axis drive mechanism that drives the test piece holder to rotate around the θ-axis, a Z-axis drive mechanism that drives the first stage in the Z-axis direction, and a control means that drives and controls each of these drive mechanisms.

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