Jig and method for manufacturing structure formed with opening

Abstract

To suppress occurrence of poor appearance in a structure which is a processing object.SOLUTION: A jig for forming an opening in a structure includes a rotary shaft part, and a blade part, wherein the rotary shaft part has an end face part formed on a tip side of the rotary shaft part, and at least the three or more blade parts are provided on the edge part of the end face part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a jig and a method for manufacturing a structure with an opening formed therein. [Background technology]

[0002] Patent Document 1 discloses a rear bumper made of resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-240541 Summary of the Invention [Problem to be solved by the invention]

[0004] In structural bodies such as rear bumpers, openings may be formed depending on the application. Such openings can be formed using a variety of methods, for example, using a drill with a cone-shaped tip that protrudes from the center. However, because such drills contact the structure at a single point when pressed against it, they are prone to core wobble due to their structure, which can cause uneven force application from the drill to the structure, potentially resulting in poor appearance such as whitening of the opening edges or the formation of burrs.

[0005] The present invention has been made in view of the above circumstances, and aims to prevent the occurrence of defects in appearance in a structure that is an object to be processed. [Means for solving the problem]

[0006] According to the present invention, the following inventions are provided. [1] A jig for forming an opening in a structure, comprising a rotating shaft portion and a blade portion, the rotating shaft portion having an end surface portion formed on the tip side of the rotating shaft portion, and at least three or more of the blade portions provided on the edge portion of the end surface. [2] The jig according to [1], wherein the end surface portion is located closer to the front than the tip of the blade portion in the direction in which the jig is pressed against the structure. [3] A jig as described in [1] or [2], wherein a hole portion penetrating the rotating shaft portion is formed in the rotating shaft portion, and the hole portion is connected to the end surface portion. [4] A method for manufacturing a structure with an opening formed therein using the jig described in any one of [1] to [3], the method comprising an opening forming step, in which the jig is rotated while being pressed against the structure to form an opening in the structure, thereby manufacturing the structure with an opening formed therein, the method comprising: the jig comprising a rotating shaft portion and a blade portion, the rotating shaft portion having an end surface portion formed on the tip side of the rotating shaft portion, and at least three or more of the blade portions provided on the edge portion of the end surface portion. [Effects of the Invention]

[0007] In the present invention, at least three cutting edges are provided on the edge of the end face of the rotating shaft, so that when pressed against the structure to be machined, the structure comes into contact with three or more points, suppressing core wobble, thereby preventing appearance defects such as whitening and burrs from occurring on the surface of the structure. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram of a processing device 1 according to an embodiment and a structure 10 which is an object to be processed. [Figure 2] Fig. 2A is a perspective view of the jig 2. Fig. 2B is a front view of the jig 2 shown in Fig. 2A. [Figure 3] Fig. 3A is a side view of the jig 2 shown in Fig. 2A. Fig. 3B is a cross-sectional view taken along a plane passing through the holes Op1, Op2, and Op3 shown in Fig. 2A. [Figure 4] FIG. 4 is an enlarged front view of the jig 2 with the cutting edge 2b cut along the line AA shown in FIG. 3A. [Figure 5]Fig. 5A shows the state in which the tip (top 2b1) of jig 2 hits the surface of structure 10. Fig. 5B shows the state in which jig 2 penetrates structure 10 and circular punched body 11 falls. Fig. 5C shows the state in which jig 2 has returned to the standby position and apertured structure 13 in which aperture 12 has been formed. [Figure 6] FIG. 6 is a front view of a jig 2 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes embodiments of the present invention. Various features shown in the following embodiments can be combined with each other.

[0010] 1. Explanation of the configuration of processing device 1 1, the processing device 1 includes a jig unit U1, a linear drive unit U2, and a control unit 6. The jig unit U1 includes a jig 2 and a rotation drive unit 3b. The linear drive unit U2 includes a shaft 4 and a housing 5.

[0011] The processing device 1 performs various operations under the control of the control unit 6. In FIG. 1, a structure 10 is an object to be processed by the processing device 1, and is fixed by a fixing means (not shown) so that it will not move even when a jig unit U1 of the processing device 1 hits it.

[0012] The structure 10 is a plate-shaped resin member, and in this embodiment, it is solid. The structure 10 is not limited to a solid resin member, but may also be a resin foam molded body. The resin constituting the structure 10 can be a resin composition containing a thermoplastic resin such as polyolefin. Examples of polyolefin include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof. In this embodiment, the structure 10 is preferably a member having a design surface and a non-design surface opposite the design surface, such as a rear bumper of a car. The design surface corresponds to the surface exposed to human eyes (front surface), and the non-design surface corresponds to the surface not exposed to human eyes (rear surface).

[0013] 1-1. Jig unit U1 1-1-1. Jig 2 As shown in FIG. 1, jig 2 is attached to rotation drive unit 3b. Jig 2 is a metal tool that functions to form a circular opening in structure 10. As shown in FIG. 2A, jig 2 includes a rotation shaft portion 2a and a plurality of cutting edges 2b. Rotation shaft portion 2a includes a body portion 2a1, a base shaft portion 2a2, an end surface portion 2a3, and a recess 2a4. The detailed configuration of jig 2 will be described with reference to FIGS. 2A to 4.

[0014] 1-1-1-1. Rotating shaft portion 2a <Torso 2a1> The body portion 2a1 has an end surface portion 2a3 connected to its tip end and a base shaft portion 2a2 connected to its base end. In this embodiment, the body portion 2a1 is configured in a cylindrical shape. The axial width D1 (mm) of the body portion 2a1 is, for example, 10, 15, 20, 25, 30, 35, or 40 mm, and may be within a range between any two of the numerical values ​​exemplified here. The diameter φ1 (mm) of the body portion 2a1 is, for example, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, or 50 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0015] The body portion 2a1 is formed with holes Op1 to Op4 for air-cooling the jig 2. While the jig 2 is machining the structure 10, the jig 2 heats up due to friction between the jig 2 and the structure 10. If the jig 2 is used in a high-temperature state, the heat will cause the structure 10 to stretch, increasing the likelihood of burrs and the like being generated. For this reason, the jig 2 is formed with holes Op1 to Op4 to promote cooling of the jig 2. In this way, the jig 2 is formed with holes (holes Op1 to Op4) that penetrate the body portion 2a1, which makes it easier for air to flow in and out of the jig 2, thereby improving the cooling effect of the jig 2.

[0016] The hole Op1 is formed to extend parallel to the rotation axis O. The radial center position of the hole Op1 coincides with the position of the rotation axis O. One side (opening end side) of the hole Op1 opens to the recess 2a4, and the other side (terminal end side) is located within the trunk portion 2a1. One side of hole Op2, hole Op3, and hole Op4 communicate with hole Op1, and the other side opens to the outer peripheral surface of trunk portion 2a1. Hole Op2 and hole Op3 are arranged to be aligned in the axial direction (direction parallel to rotation axis O) of jig 2. Hole Op3 and hole Op4 are also arranged to be aligned in a straight line.

[0017] The depth L1 (mm) of the hole Op1 is set so that (depth L1 of hole Op1) / (width D1 of body portion 2a1) is the following value or range: Specifically, (depth L1 of hole Op1) / (width D1 of body portion 2a1) is, for example, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, or 1.00, and may be within a range between any two of the numerical values ​​exemplified here. Furthermore, the diameter φ2 (mm) of the hole Op1 is set so that (diameter φ2 of hole Op1) / (diameter φ1 of body portion 2a1) is the following value or range. Specifically, (diameter φ2 of hole Op1) / (diameter φ1 of body portion 2a1) is, for example, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40, and may be within a range between any two of the numerical values ​​exemplified here. The diameters of the holes Op2, Op3, and Op4 are smaller than the diameter of the hole Op1.

[0018] In the embodiment, one hole Op1 is formed, but this is not limited thereto and multiple holes may be formed. Also, in the embodiment, three holes (hole Op2, hole Op3, and hole Op4) communicating with hole Op1 are formed, but this is not limited thereto and the number may be one, two, or three or more.

[0019] <Basic shaft part 2a2> The distal end of the base shaft portion 2a2 is connected to the trunk portion 2a1, and the proximal end is attached to the rotation drive unit 3b (described later). In this embodiment, the base shaft portion 2a2 is cylindrical. The axial width D2 (mm) of the base shaft portion 2a2 is, for example, 20, 25, 30, 35, 40, 45, or 50 mm, and may be within a range between any two of the numerical values ​​exemplified here. The diameter φ3 (mm) of the base shaft portion 2a2 is, for example, 8, 9, 10, 11, 12, 13, 14, or 15 mm, and may be within a range between any two of the numerical values ​​exemplified here. The diameter φ3 of the base shaft portion 2a2 is smaller than the diameter φ1 of the trunk portion 2a1.

[0020] <End face part 2a3> The end surface portion 2a3 is formed on the tip side of the rotary shaft portion 2a. The end surface portion 2a3 is connected to the body portion 2a1. Specifically, the end surface portion 2a3 is formed to extend in an annular shape, and a recess 2a4 is formed on the inside. The end surface portion 2a3 is formed to protrude from the body portion 2a1. The blade portion 2b is connected to the end surface portion 2a3. The end surface portion 2a3 has an edge portion Ed on which the blade portion 2b is provided. In this embodiment, the edge portion Ed is arc-shaped and corresponds to a position on the diameter (outer diameter) of the end surface portion 2a3. In this embodiment, the diameter (mm) of the end surface portion 2a3 is the same as the diameter φ1 of the body portion 2a1. Note that the diameter (mm) of the end surface portion 2a3 may be larger than the diameter φ1 (mm) of the body portion 2a1.

[0021] <Recess 2a4> The recess 2a4 is formed so as to be surrounded by the end surface portion 2a3. The formation of the recess 2a4 in the jig 2 allows chips from the structure 10 to escape. In other words, even if chips are generated during the process of pressing the jig 2 against the structure 10 and machining an opening in the structure 10, the chips escape into the recess 2a4, thereby preventing the movement (progression) of the jig 2 from being hindered. The depth L2 (mm) of the recess 2a4 is specifically, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0022] 1-1-1-2.Blade part 2b The blade portions 2b have the function of cutting the structure 10 as the jig 2 rotates around the rotation axis O. The blade portions 2b have a top portion 2b1, a base portion 2b2, an edge portion 2b3, an inclined surface 2b4, and an outer peripheral surface 2b5. The jig 2 has at least three blade portions 2b. In this embodiment, the jig 2 has four blade portions 2b. In this embodiment, the four blade portions 2b have the same shape.

[0023] <Top 2b1> The apex 2b1 is the portion of the jig 2 that first comes into contact with the structure 10 when the jig 2 is butted against the structure 10. In other words, the apex 2b1 is located at the tip of the jig 2. As shown in FIG. 3A, the apex 2b1 is formed at the apex of a curve that convex toward the tip when the jig 2 is viewed from the side. On the other hand, the apex 2b1 is formed sharply when the jig 2 is viewed in cross section as shown in FIG. 3B. The apex 2b1 forms an angle θ when the jig 2 is viewed in cross section as shown in FIG. 3B. The angle θ is the angle formed by the outer peripheral surface 2b5 of the cutting edge 2b and the inclined surface 2b4. Specifically, the angle θ (degrees) is, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, and may be within a range between any two of the numerical values ​​exemplified here.

[0024] 2B, in this embodiment, the angle α (central angle) formed between adjacent blade portions 2b in the circumferential direction is 90 degrees. Specifically, the angle α is the angle between the position of the apex 2b1 of one blade portion 2b and the position of the apex 2b1 of the blade portion 2b adjacent to this blade portion 2b in the circumferential direction. If the angle α is 90 degrees, as shown in FIG. 2B, in the process of manufacturing the jig 2, by machining a cylindrical steel material with a tool in the direction indicated by the arrow Ar, it is possible to efficiently form a portion corresponding to the blade portion 2b, thereby reducing the number of steps required to manufacture the jig 2.

[0025] In the embodiment, the four blade portions 2b are described as being arranged at equal intervals in the circumferential direction (angle α is 90 degrees), but this is not limited to this. The four blade portions 2b do not have to be arranged at equal intervals in the circumferential direction; in other words, the values ​​of the four angles α may be different. In this case, the angle α (degrees) may be set to, for example, 60, 70, 80, 90, 100, 110, or 120 degrees, and the angle α may be defined within a range between any two of the values ​​exemplified here.

[0026] <Base 2b2> The base 2b2 is the portion where the blade portion 2b is connected to the end surface portion 2a3. Two base portions 2b2 are formed on each blade portion 2b. As shown in FIG. 2B, the range in which each blade portion 2b is formed can be determined by an angle β. The angle β is the angle between the position of one base portion 2b2 and the position of the other base portion 2b2. The angle β (degrees) can be, for example, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, or 60 degrees, or it can be within a range between any two of the values ​​exemplified here.

[0027] <Edge part 2b3> As shown in Fig. 3A, edge portion 2b3 is formed to be convex from base portion 2b2 to apex 2b1 when viewed from the side. Specifically, edge portion 2b3 protrudes from a line connecting base portion 2b2 and apex 2b1 when viewed from the side, and has a rounded shape (a curved shape that is convex toward the tip) from base 2b2 to apex 2b1. Because edge portion 2b3 has such a rounded shape, cutting edge 2b is less likely to break.

[0028] 2B and 4, when the edge portion 2b3 is viewed from the front, the edge portion Ed, the edge portion 2b3 of the cutting portion 2b, and the outer peripheral surface 2b5 of the cutting portion 2b are arranged concentrically. As shown in FIG. 3A, the edge portion 2b3 is formed symmetrically with respect to the apex 2b1. That is, the cutting portion 2b has a pair of edge portions 2b3 arranged on either side of the apex 2b1. Therefore, even if one of the edge portions 2b3 is damaged, the jig 2 can be continued to be used without replacing it by reversing the rotation direction of the jig 2.

[0029] Next, the angle of the edge portion 2b3 in the rotation direction (circumferential direction) will be described. As shown in Fig. 4, the angle of the edge portion 2b3 in the rotation direction can be defined as the angle between a tangent to the edge portion 2b3 and a line on the inclined surface 2b4. For example, angle r1 in the rotation direction of edge portion 2b3 at the position of base portion 2b2 is the angle between line t1 and tangent line q1. Here, line t1 is a straight line at the lowest end of inclined surface 2b4. Tangent line q1 is a tangent line to the concentric circle of edge portion Ed and passes through the position of base portion 2b2. Both line t1 and tangent line q1 are located on a first plane perpendicular to rotation axis O. Furthermore, angle r2 in the rotational direction of edge portion 2b3 at position P where blade portion 2b is cut is the angle between line t2 and tangent line q2. Here, line t2 is a straight line in the middle of inclined surface 2b4 and is parallel to line t1. Tangent line q2 is a tangent to the concentric circle of edge portion Ed and passes through position P where edge portion 2b3 is cut. Line t2 and tangent line q2 are both located on a second plane perpendicular to rotation axis O. This second plane does not overlap with the first plane described above, but is parallel to it.

[0030] The angle of the edge portion 2b3 in the rotation direction is maximum at the position of the base 2b2 (corresponding to the angle r1 described above), gradually decreases toward the apex 2b1, and is minimum (0 degrees in this embodiment) at the position of the apex 2b1. That is, the edge portion 2b3 is formed so that the angle of the edge portion 2b3 in the rotation direction decreases from the base 2b2 to the apex 2b1. In other words, the angle of the edge portion 2b3 in the rotation direction increases from the apex 2b1 to the base 2b2. Therefore, the angle r1 described above is greater than the angle r2. As a result, when the jig 2 is initially pressed against the structure 10, the portion of the edge portion 2b3 with a smaller angle comes into contact with the structure 10, and the blade portion 2b easily bites into the structure 10. Then, as the insertion depth of the blade portion 2b increases, the portion of the edge portion 2b3 with a larger angle comes into contact with the structure 10, and the structure 10 is quickly cut.

[0031] The angle r1 (degrees) of the rotation direction of the edge portion 2b3 is specifically, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, and may be within a range between any two of the numerical values ​​exemplified here.

[0032] When edge portion 2b3 is cut along a cross section parallel to the cross section shown in FIG. 3B, the angle of the tip of edge portion 2b3 is the same as angle θ of apex 2b1 described above.

[0033] <Inclined surface 2b4 and outer peripheral surface 2b5> The inclined surface 2b4 forms the inner surface of the blade portion 2b. In the embodiment, the inclined surface 2b4 is a flat surface. The inclined surface 2b4 is formed from the top portion 2b1 to the end surface portion 2a3. The outer peripheral surface 2b5 is connected to the outer peripheral surface of the body portion 2a1. When the jig 2 is viewed from the front, the outer peripheral surface 2b5 is located on the outer peripheral surface of the body portion 2a1 and on a concentric circle with the edge portion Ed of the end surface portion 2a3.

[0034] Because the jig 2 has a flat inclined surface 2b4 and an outer peripheral surface 2b5, as described above, the angle of the rotational direction of the edge portion 2b3 increases from the apex 2b1 to the base 2b2. This increases the insertion depth of the blade portion 2b, and the larger-angled portion of the edge portion 2b3 comes into contact with the structure 10, quickly cutting the structure 10. In other words, since the cutting is not performed only on the smaller-angled portion of the edge portion 2b3 but also on the larger-angled portion of the edge portion 2b3, cutting proceeds all at once, reducing the generation of shavings. This prevents shavings from adhering to the jig 2 or clogging the jig 2 while the jig 2 is rotating, which could result in damage (scratching) of the structure 10. This is particularly significant when the jig 2 is pressed against the design surface of the structure 10, as it can prevent damage to the design surface. In addition, with conventional drills, chips may wrap around the drill, which can easily damage the structure when the chips come into contact with the structure, and the work of removing the chips is also a burden. The jig 2 according to the embodiment can reduce these disadvantages.

[0035] 1-1-2. Rotation drive unit 3b The rotational drive unit 3b shown in FIG. 1 has the function of rotating the jig 2. The rotational drive unit 3b has a chuck (not shown), and the jig 2 is attached to the rotational drive unit 3b by holding the base shaft portion 2a2 in this chuck. The rotational drive unit 3b includes a housing 3b1 and a movable portion 3b2. A motor for rotating the jig 2 is built into the housing 3b1. The movable portion 3b2 is fixed to the housing 3b1. In this embodiment, the movable portion 3b2 is configured as a nut with an internal thread that can be threaded onto the shaft portion 4 of the linear drive unit U2.

[0036] 1-2. Linear drive unit U2 The linear drive unit U2 shown in FIG. 1 has the function of moving the jig unit U1 in a linear direction (up and down in this embodiment). In other words, the linear drive unit U2 has the function of moving the jig unit U1 forward or backward (down or up) along its rotation axis. The linear drive unit U2 includes a shaft 4 and a housing 5. In this embodiment, the shaft 4 is configured as a feed screw having a male thread that meshes with the movable part 3b2. A motor for rotating the shaft 4 is built into the housing 5. By driving the motor to rotate the shaft 4 in one direction, the jig unit U1 can be moved forward (moved toward the structure 10), and by rotating the shaft 4 in the other direction, the jig unit U1 can be moved backward (moved away from the structure 10). Therefore, by switching the rotation direction of the shaft 4, the traveling direction of the jig unit U1 can be switched.

[0037] Here, the linear drive unit U2 is configured to linearly move the jig unit U1 using a feed screw mechanism, but the jig unit U1 may also be linearly moved using another drive mechanism such as a cylinder mechanism. Also, to make the linear movement of the jig unit U1 more stable, the jig unit U1 may be linearly moved while being guided by a linear guide.

[0038] 2. Manufacturing method of the structure 13 with openings formed This method comprises a fixing step, an opening forming step, and a removing step, each of which will be described below.

[0039] 2-1.Fixing process In the fixing step, the structure 10 is fixed using a fixing means (not shown). During the fixing step, the jig unit U1 is preferably in the standby position shown in Fig. 1. This prevents the jig 2 from damaging the structure 10.

[0040] 2-2. Opening formation process In the opening forming step, the jig 2 is rotated and pressed against the structure 10 to form an opening 12 in the structure 10, thereby producing an opening-formed structure 13. Specifically, in the opening forming step, the jig 2 is advanced from the standby position shown in Fig. 1 toward the structure 10, and the jig 2 reaches the pressing start position shown in Fig. 5A, where the jig 2 (blade portion 2b) comes into contact with the structure 10 for the first time. The rotation speed of the jig 2 may be increased from the rotation speed of the jig 2 at the pressing start position at a predetermined timing when the blade portion 2b enters the structure 10. The predetermined timing can be set according to, for example, the plate thickness of the structure 10. 5B, the jig 2 is advanced until the blade portion 2b penetrates a predetermined distance from the rear surface of the structure 10 (the surface opposite to the surface pressing the jig 2 against the structure 10). The predetermined distance (mm) is, for example, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, or 4.0 mm, and may be within a range between any two of the numerical values ​​exemplified here. 5B and 5C, when the jig 2 penetrates the structure 10, the circular punched body 11 that was a part of the structure 10 falls, forming a circular opening 12 in the structure 10, and producing an opening-formed structure 13. After the jig 2 forms the opening 12, it is preferable to retract the jig 2 to a standby position, as shown in FIG. It is preferable that the advancing speed of the jig 2 is constant from the time when the jig 2 (blade portion 2b) is positioned at the pressing start position until the time when the jig 2 (blade portion 2b) penetrates the structure 10 by a predetermined distance.

[0041] 2-3.Removal process In the removal step, the opening-formed structure 13, which has been fixed by the fixing means, is released. During the removal step, the jig unit U1 is preferably in a standby position away from the structure 10. This prevents the jig 2 from damaging the opening-formed structure 13.

[0042] 3. Functions and Effects of the Embodiments For example, various structures, such as rear bumpers, may have openings formed therein depending on their intended use, as in the structure 10 described above. Such openings can be formed using various methods, including, for example, a drill with a tapered shape that protrudes from the center. However, the inventors have found that when a drill with such a shape is used to form an opening in a structure, chips are likely to be generated between the drill and the structure when the drill is pressed against the structure, and the chips are likely to cause defects in appearance, such as scratches, on the surface of the structure (the surface against which the drill is pressed). The inventors have also found that, due to the structure of the drill, the amount of chips generated can be large, and the chips are likely to wrap around and adhere to the drill. For this reason, it is believed that when a hole is formed in a structure using such a drill, the chips are likely to be pressed against the structure, damaging the structure.

[0043] One possible way to hide these scratches is to press a drill against the non-design surface of the structure. However, because the drill described above makes single-point contact when pressed against the structure, it is prone to core runout due to its structure. Furthermore, when the drill is pressed against the structure, force is concentrated at the sharp point in the center of the drill, which can easily deform the structure itself and exacerbate core runout. Therefore, even with this method, core runout of the drill can bias the force applied from the drill to the structure, applying a strong force (pressure) to the edge of the opening in the structure. This can deform (stretch) the resin that makes up the opening edge, potentially resulting in poor appearance, such as whitening or burrs on the edge of the opening on the design surface (the surface opposite the non-design surface).

[0044] In contrast, the jig 2 according to the embodiment can cut the structure 10 by cutting into it with a plurality of independent blade portions 2b, making it possible to suppress the generation of chips. Furthermore, unlike a drill, the blade portions 2b are not on the rotation axis O, so it is possible to suppress the chips from wrapping around (sticking to) the blade portions 2b. Therefore, the jig 2 according to the embodiment can suppress the occurrence of defects in appearance, such as scratches, on the structure 10 due to the chips.

[0045] Furthermore, when the jig 2 according to the embodiment is pressed against the structure 10, which is the processing target, it comes into contact with the structure at three or more points. This suppresses wobbling of the jig 2 and more reliably optimizes the angle at which the jig 2 approaches the structure 10. This uniformly distributes the force applied to the edge of the opening 12 from the jig 2, suppressing deformation of the resin that forms the edge of the opening 12, and as a result, it is possible to suppress poor appearance such as whitening and burrs. Instead of providing two blade portions 2b of the jig 2, a needle-like member may be provided at the center of the four blade portions 2b on the rotation axis O of the jig 2 as a means of suppressing wobble. However, with this method, the needle-like member pierces the punched body 11, so the punched body 11 must be pulled out every time an opening is formed, which is time-consuming. Furthermore, if the needle-like member and the top 2b1 of the blade portion 2b are aligned in a straight line, the posture of the jig 2 may become unstable, and wobble may still be unavoidable.

[0046] In this way, the jig 2 of the embodiment can effectively suppress poor appearance caused by chips and core wobble, and is therefore effective when machining openings from the design surface side of the structure 10, as well as when machining openings from the non-design surface side of the structure 10.

[0047] 4. Variations Although the jig 2 according to the embodiment is configured to have four blade portions 2b, it may also be configured to have three blade portions 2b, as shown in FIG. 6. In the jig 2 according to the modified example, the blade portions 2b are arranged so that connecting the apexes 2b1 of the blade portions 2b forms an equilateral triangle. In other words, the angle α corresponding to the central angle between the two apexes 2b1 is 120 degrees. The jig 2 according to the modified example can also achieve the same effect as the jig 2 according to the embodiment. The jig 2 may also have five or more blade portions. [Explanation of symbols]

[0048] 1: Processing equipment 2: Jig 2a: Rotating shaft 2a1: Torso 2a2: Base part 2a3: End face part 2a4: recess 2b:Blade part 2b1 :Top 2b2 :Base 2b3: Edge part 2b4: Inclined surface 2b5: Outer surface 3b: Rotation drive unit 3b1: Cabinet 3b2: Moving part 4: Shaft 5: Housing 6: Control section 10 :Structure 11: punched body 12:Aperture 13: Opening-formed structure Ed: Edge L1: Depth L2: Depth O: Rotation axis Op1: hole part Op2: hole part Op3: hole part Op4: Hole U1: Jig unit U2: Linear drive unit q1: tangent q2: tangent r1 :Angle r2 :Angle α :Angle β :Angle θ: angle

Claims

1. A jig for forming an opening in a structure, The cutting tool has a rotating shaft and a blade. the rotating shaft portion has an end surface portion formed on a tip side of the rotating shaft portion, The jig has at least three or more of the blades provided on the edge of the end face portion.

2. The jig according to claim 1, The end surface portion is located closer to the front than the tip of the blade portion in a direction in which the jig is pressed against the structure.

3. The jig according to claim 1, The rotary shaft portion has a hole portion formed therethrough, The hole portion communicates with the end surface portion.

4. A method for manufacturing a structure with an opening formed therein using the jig according to any one of claims 1 to 3, An opening forming step is provided, In the opening forming step, the jig is rotated while being pressed against the structure, thereby forming an opening in the structure, thereby manufacturing the structure with the opening formed; The jig includes a rotating shaft portion and a blade portion, the rotating shaft portion has an end surface portion formed on a tip side of the rotating shaft portion, The method comprises providing at least three or more of the cutting edges on the edge of the end surface portion.

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