Advanced tools

Abstract

This provides a tip tool that can be attached to the spindle without any wobbling and can be manufactured inexpensively. [Solution] A tip tool 10 that can be interchangeably attached to the spindle portion 92 of an electric power tool 90, wherein the spindle portion 92 is provided with an annular portion 95 in which a plurality of recesses 97 are continuously and evenly formed around the entire circumference of its inner surface, and the tip tool 10 has a flat plate-shaped engaging portion 20 that engages with the inside of the annular portion 95, a tip portion 30, and a connecting portion 40 that connects the engaging portion 20 and the tip portion 30, wherein the engaging portion 20 has a polygonal shape with a plurality of corners and has a mounting hole portion 21 into which a mounting fastener 96 that is attached to the spindle portion 92 is inserted, and at least two of the plurality of corners, locking corners 22, 23 are locked and engaged with the recesses 97.

Description

Technical Field

[0001] The present invention relates to a tip tool.

Background Art

[0002] Conventionally, there is a power tool called a multi-tool that can perform cutting, polishing, peeling, etc. with a single unit by replacing the tip tool. For example, the power tool described in Patent Document 1 is provided with a spindle portion for attaching the tip tool. The spindle portion has an annular portion that fits three-dimensionally with the tip tool. A plurality of concave portions are continuously formed on the entire circumference of the inner peripheral surface of the annular portion.

[0003] The tip tool has an engaging portion having a three-dimensional shape that fits into the annular portion, as described in, for example, Patent Document 2. The tip tool is attached to the spindle portion without play by the three-dimensional fitting of the engaging portion and the annular portion. As a result, the power of the multi-tool is efficiently transmitted to the tip tool.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the blade of the tip tool as described above is too thin to be suitable for work such as cutting concrete. If the tip tool is formed of a thick metal plate, it is difficult to form the engaging portion three-dimensionally, and the manufacturing cost increases. Therefore, there has been a demand for a tip tool that can be attached to the spindle portion without play and can be manufactured at a low cost.

[0006] This invention was completed based on the circumstances described above, and aims to provide an insert tool that can be attached to the spindle without wobbling and can be manufactured at low cost. [Means for solving the problem]

[0007] The tip tool of the present invention is a tip tool that can be interchangeably attached to the spindle portion of an electric power tool, wherein the spindle portion is provided with an annular portion having a plurality of recesses formed continuously and evenly around the entire circumference of its inner surface, and the tip tool has a flat plate-shaped engaging portion that engages with the inside of the annular portion, a tip portion, and a connecting portion that connects the engaging portion and the tip portion, wherein the engaging portion has a polygonal shape with a plurality of corners and has a mounting hole portion into which a mounting fastener attached to the spindle portion is inserted, and at least two of the plurality of corners are locked and engaged with the recesses. [Effects of the Invention]

[0008] According to the present invention, the engaging portion is fixed to the annular portion without looseness by inserting the mounting fastener into the mounting hole while the locking angle portion is locked into the recess of the annular portion. Since the engaging portion does not need to be formed into a three-dimensional shape, it can be manufactured at low cost. Therefore, the tip tool can be attached to the spindle portion without looseness and can be manufactured at low cost. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing how the tip tool in Example 1 is attached to and used with a power tool. [Figure 2] This is a partially enlarged perspective view showing how the tip tool is attached to the spindle. [Figure 3] This is a view of the tool tip from below in the Y-axis direction. [Figure 4] This is a cross-sectional view showing the tip of a tool. [Figure 5] This is a view from below in the Y-axis direction, and is a partially enlarged view showing the area around the spindle with the tip tool attached. [Figure 6]This figure shows the tip tool in Example 2, where (a) is a view of the tip tool from below in the Y-axis direction, and (b) is a cross-sectional view of the tip tool. [Figure 7] This is a partially enlarged view showing the area around the spindle portion with the tip tool attached in another embodiment (1), and is viewed from below in the Y-axis direction. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present invention are shown below. [1] The tip tool of the present invention is a tip tool that can be interchangeably attached to the spindle portion of an electric power tool, wherein the spindle portion is provided with an annular portion having a plurality of recesses formed continuously and evenly around the entire circumference of its inner surface, the tip tool has a flat plate-shaped engaging portion that engages with the inside of the annular portion, a tip portion, and a connecting portion that connects the engaging portion and the tip portion, the engaging portion has a polygonal shape having a plurality of corners and has a mounting hole portion into which a mounting fastener attached to the spindle portion is inserted, and at least two of the plurality of corners are locked and engaged with the recesses.

[0011] With this configuration, the locking corner is locked into the recess of the annular portion, and by inserting the mounting fastener into the mounting hole, the engaging portion is fixed to the annular portion without any looseness. Since the engaging portion does not need to be formed into a three-dimensional shape, it can be manufactured inexpensively. Therefore, the tip tool can be attached to the spindle portion without any looseness and can be manufactured inexpensively.

[0012] [2] In the tip tool described in [1] above, the locking angle may be formed on the connecting portion that connects the engaging portion and the connecting portion. With such a configuration, the play of the engaging portion can be limited at a position close to the tip, so that the power of the multi-tool can be transmitted to the tip tool more efficiently.

[0013] [3] In the tip tool described in [1] or [2] above, the engaging portion, the tip portion, and the connecting portion may be made of a single metal plate. According to such a configuration, by using a metal plate with a large thickness dimension, the durability of the tip portion can be improved, and the tip tool can be manufactured more easily than in the case of joining a plurality of metal plates.

[0014] [4] In the tip tool described in [1] or [2] above, the tip portion may be made of another metal plate having a larger thickness dimension than the metal plate constituting the engaging portion. According to such a configuration, the tip portion can be thickened and the durability of the tip portion can be improved.

[0015] [5] In the tip tool described in [4] above, the hardness of the engaging portion may be equal to or higher than the hardness of the tip portion. According to such a configuration, since the engaging portion with high hardness is difficult to deform, the power of the multi-tool can be transmitted to the tip tool more efficiently.

[0016] [6] In the tip tool described in any one of [1] to [5] above, the tip surface of the tip portion may be configured as a cut-off surface. According to such a configuration, since the thickness dimension of the tip surface of the tip portion is larger than that of chamfering obliquely, the durability of the tip portion can be improved.

[0017] [7] In the tip tool described in any one of [1] to [6] above, the width dimension of the tip portion may be larger than the width dimension of the engaging portion. According to such a configuration, since it is easy to scrape a large area of concrete, the work of scraping concrete can be performed efficiently.

[0018] <Example 1> Hereinafter, Example 1 embodying the present invention will be described in detail with reference to FIGS. 1 to 5. As shown in FIG. 1, the tip tool 10 is attached to and used with the power tool 90. The tip tool 10 is detachably attached to the power tool 90. The power tool 90 is a multifunctional tool that can perform cutting, polishing, peeling, etc. with a single unit by replacing the tip tool 10. The power tool 90 may be a commercially available one called a multi-tool.

[0019] As shown in FIG. 1, the power tool 90 has a main body portion 91, a spindle portion 92, and a lever portion 93, and vibrates the tip tool 10 fixed to the spindle portion 92 at a high speed. A battery 94 can be attached to and detached from the main body portion 91. The vibration frequency at which the power tool 90 vibrates the tip tool 10 is, for example, about 10,000 to 20,000 times per minute. The tip tool 10 fixed to the spindle portion 92 repeatedly swings in an arc direction around the axis by the drive of a motor (not shown). The range of the swing angle is about 2 to 5 degrees to the left and right. The lever portion 93 is operated when attaching and detaching the tip tool 10 to the spindle portion 92.

[0020] Hereinafter, for the convenience of explanation, in each component, the directions in FIG. 1 will be unified and described in the directions in the specification. Specifically, the vertical direction in FIG. 1 is the vertical direction, the vibration direction of the tip tool 10 is the left-right direction, and the direction orthogonal to the vertical direction and the left-right direction is the front-back direction. "Orthogonal" includes not only a state of being strictly orthogonal but also a state of being generally orthogonal. Also, the side where the tip tool 10 is fixed in the Y-axis direction is the lower side, and the side where the tip tool 10 is fixed in the Z-axis direction is the front side. The central axis of the swing of the tip tool 10 is parallel to the Y-axis. "Parallel" includes not only a state of being strictly parallel but also a state of being generally parallel.

[0021] In each figure, the positive direction side of the X-axis is the left side, the negative direction side of the X-axis is the right side, the positive direction side of the Y-axis is the upper side, the negative direction side of the Y-axis is the lower side, the positive direction side of the Z-axis is the front side, and the negative direction side of the Z-axis is the rear side. In each drawing, for the convenience of explanation, a part of the configuration may be shown exaggeratedly or simplified. Also, the dimensional ratios of each part may be different from the actual ones.

[0022] Figure 2 shows how the tip tool 10 is attached to the spindle portion 92. The spindle portion 92 has an annular portion 95 and a mounting fixture 96. The annular portion 95 is a three-dimensional cylindrical shape with height in the vertical direction, and a plurality of recesses 97 are continuously and evenly formed around the entire circumference of the inner surface of the annular portion 95. Each recess 97 is composed of a pair of surface portions 99 (see Figure 5). The space between adjacent recesses 97 is a convex portion. The mounting fixture 96 is a bolt or clamp etc. that is originally provided on the power tool 90, and is used not only for fixing the tip tool 10 but also for fixing other commercially available tip tools. Figure 2 shows the case where the mounting fixture 96 is a bolt.

[0023] Figure 3 shows a view of the tip tool 10 from below in the Y-axis direction. The tip tool 10 is made of metal and has an engaging portion 20, a tip portion 30, and a connecting portion 40. The engaging portion 20 and the tip portion 30 are formed from different metal plates 11 and 12. The engaging portion 20 and the connecting portion 40 are integrally formed from a single first metal plate 11 (see Figure 4). The tip portion 30 is formed from a second metal plate 12. The material of the first metal plate 11 and the material of the second metal plate 12 may be the same or different. The strength of the first metal plate 11 and the strength of the second metal plate 12 may be the same, but it is preferable that the strength of the second metal plate 12 is higher than that of the first metal plate 11. This suppresses wear and cracking of the tip portion 30 made of the second metal plate 12, thereby improving the durability of the tip tool 10.

[0024] The hardness of the first metal plate 11 is preferably higher than that of the second metal plate 12. Since the engagement portion 20 formed by the hard first metal plate 11 is less prone to deformation, the power of the multi-tool is efficiently transmitted to the tip tool 10. The thickness dimension of the second metal plate 12 is greater than that of the metal plates used in conventional tip tools. This improves the durability of the tip portion 30 compared to the blades of conventional tip tools, making the tip tool 10 useful for cutting concrete and the like.

[0025] The thickness dimensions of the first metal plate 11 and the second metal plate 12 may be the same, but it is preferable that the thickness dimension of the second metal plate 12 is greater than that of the first metal plate 11. Specifically, it is preferable that both the thickness dimensions of the first metal plate 11 and the second metal plate 12 are within the range of 0.5 mm to 2.0 mm. If there is a difference between the thickness dimensions of the first metal plate 11 and the second metal plate 12, the difference should be about 0.5 mm. This increases the thickness dimension of the second metal plate 12 while suppressing excessive stress concentration on the connecting portion 40 of the first metal plate 11, thereby improving the durability of the tip tool 10.

[0026] As shown in Figure 3, the engaging portion 20 is flat and has a hexagonal shape with 6 corners and 6 sides 24. A mounting hole 21 for inserting the mounting fastener 96 is formed in the center of the engaging portion 20. The mounting hole 21 penetrates the engaging portion 20 in the thickness direction. The engaging portion 20 has a first locking corner portion 22 and a second locking corner portion 23 that engage with the recess 97.

[0027] The first locking corner portion 22 is formed by four of the six corner portions of the engaging portion 20. The four first locking corner portions 22 are provided at equal angular intervals in approximately half of the area of ​​the engaging portion 20 opposite to the connecting portion 40. Each first locking corner portion 22 is formed by a pair of continuous edges 24. When the angles of the pair of edges 24 of the first locking corner portion 22 and the pair of surfaces 99 of the recess 97 match, the engaging portion 20 is fixed more firmly.

[0028] The second locking corner portion 23 is formed in the connecting portion 25 that connects the engaging portion 20 and the connecting portion 40. The connecting portion 25 coincides with the fold line between the engaging portion 20 and the connecting portion 40 and is also the edge portion 24 of the engaging portion 20. The second locking corner portion 23 is composed of the edge portion 24 of the engaging portion 20 and the side edge portion 41 of the connecting portion 40, which will be described later. When the angles of the edge portion 24 and side edge portion 41 of the second locking corner portion 23 match those of the pair of surfaces 99 of the recess 97, the engaging portion 20 is fixed more firmly.

[0029] The connecting portion 40 connects the engaging portion 20 and the tip portion 30. The connecting portion 40 has an extension portion 42 extending from the engaging portion 20 toward the tip portion 30, and a connecting-side connecting portion 43 provided at the end of the extension portion 42 and joined to the tip portion 30. The extension portion 42 has left and right side edges 41. The left and right side edges 41 extend substantially parallel to each other.

[0030] The connecting joint 43 has a widening section 44 and an overlapping section 45. The left-right dimension (width) of the connecting joint 43 is greater than the left-right dimension (width) of the extension section 42. The widening section 44 gradually increases in the left-right direction from the extension section 42 towards the overlapping section 45. The overlapping section 45 is provided on the tip side of the widening section 44. The left-right dimension of the overlapping section 45 is constant. The left-right dimension of the overlapping section 45 is equal to or greater than the maximum left-right dimension of the engaging section 20 (hereinafter referred to as the maximum width W).

[0031] Figure 4 shows a cross-sectional view of the tip tool 10. As shown in Figure 4, the extension 42 extends diagonally from the joint 25 with the engaging portion 20 to the engaging portion 20. The vertical distance between the engaging portion 20 and the connecting side joint 43 is greater than the height dimension of the annular portion 95. The overlapping portion 45 is superimposed on and joined to the tip portion 30.

[0032] As shown in Figure 3, the tip portion 30 has a tip-side joint portion 31 and a blade portion 32. The tip-side joint portion 31 is rectangular in shape, and its left-right dimension (width dimension) is the same as that of the overlapping portion 45. The tip-side joint portion 31 is joined by being superimposed on the lower side of the overlapping portion 45.

[0033] The blade portion 32 is rectangular, preferably trapezoidal. The left-right dimension of the blade portion 32 gradually increases from the tip-side joint portion 31 towards the tip surface 33. The left-right dimension of the blade portion 32 is greater than the maximum width W of the engaging portion 20. The left-right dimension of the tip surface 33 of the blade portion 32 is approximately twice the maximum width W of the engaging portion 20.

[0034] As shown in Figure 4, the tip surface 33 of the blade portion 32 is made of a cut surface. The tip surface 33 of the blade portion 32 is perpendicular to the plate surface of the blade portion 32. As a result, the thickness dimension of the tip surface 33 of the blade portion 32 is greater than if the tip surface of the blade portion were beveled, which allows for more time to be spent being shaved down and thus improves the durability of the tip portion 30.

[0035] Figure 5 shows a magnified view of the area around the spindle portion 92 with the tip tool 10 attached, as seen from below in the Y-axis direction. As shown in Figure 5, the annular portion 95 has a star shape when viewed from below in the Y-axis direction and conforms to the standards known as Starlock (registered trademark), Starlock Plus (registered trademark), and Starlock Max (registered trademark). If the mounting fixture 96 is a bolt, a hole 98 into which the mounting fixture 96 is inserted is formed at the center of the back surface surrounded by the annular portion 95. The mounting fixture 96 is not shown in Figure 5. If the mounting fixture 96 is a clamp, the clamp is provided at the position of the hole 98.

[0036] Next, an example of a task using the tip tool 10 of this embodiment to scrape and remove concrete, cement, etc. will be described. First, the worker attaches the tip tool 10 to the power tool 90. If the mounting fastener 96 is a bolt, the worker opens and operates the lever part 93 and pulls out the mounting fastener 96 from the spindle part 92. Then, as shown in Figure 2, the worker fits the engaging part 20 of the tip tool 10 into the annular part 95 of the spindle part 92. At this time, the worker can select the mounting angle of the tip tool 10 relative to the annular part 95 and fit it in (see Figure 5). In Figure 5, the tip tool 10 with a different mounting angle relative to the annular part 95 is shown by a dashed line.

[0037] As shown in Figure 5, the worker aligns the mounting hole 21 of the engaging portion 20 with the hole 98 of the annular portion 95 and engages the engaging portion 20 with the inside of the annular portion 95. Specifically, the first locking corner portion 22 and the second locking corner portion 23 of the engaging portion 20 are locked into the recesses 97 of the annular portion 95, respectively.

[0038] The first locking corner portion 22 of 4 locks into the recess 97 in a region approximately half the circumference of the annular portion 95 when the engaging portion 20 is engaged with the annular portion 95. Each of the first locking corner portions 22 fits into the recess 97, and the two sides 24 constituting the first locking corner portion 22 are positioned along the two surfaces 99 constituting the recess 97. The two sides 24 of the first locking corner portion 22 and the two surfaces 99 of the recess 97 are in close proximity or in contact with each other.

[0039] The second locking corner portion 23 of the 2 engages with the annular portion 95 at the position closest to the tip portion 30 of the engaging portion 20. The edge portion 24 constituting the second locking corner portion 23 is positioned along the surface portion 99 of the recess 97 on the rear side (upper side) of the annular portion 95, and the side edge portion 41 constituting the second locking corner portion 23 is positioned along the surface portion 99 of the recess 97 on the front side (lower side) of the annular portion 95 (see Figure 4). The edge portion 24 of the second locking corner portion 23 and the surface portion 99 of the recess 97, and the side edge portion 41 of the second locking corner portion 23 and the surface portion 99 of the recess 97 are in close proximity or in contact with each other. The tip tool 10 has its play in the XZ direction limited by the locking of the first locking corner portion 22 and the second locking corner portion 23 with the recess 97 of the annular portion 95.

[0040] Next, the mounting fastener 96 is inserted into the mounting hole 21 according to the type of power tool 90. Specifically, if the mounting fastener 96 is a bolt, the operator manually inserts the mounting fastener 96 from the mounting hole 21 of the engaging portion 20 to the hole 98 of the annular portion 95, as shown in Figure 2, and then returns the lever portion 93 to lock it in place. This limits the play of the tip tool 10 in the Y-axis direction.

[0041] The tip tool 10 is fixed to the spindle portion 92 with its first locking corner portion 22 and second locking corner portion 23 locked into the recess 97 of the annular portion 95 and secured by the mounting fixture 96, thereby limiting play in the XZ plane direction and the Y axis direction. In this way, even though the engaging portion 20 is plate-shaped, play with the annular portion 95 can be prevented, similar to conventional three-dimensional engaging portions. Therefore, since the engaging portion 20 of the tip tool 10 does not need to be formed into a three-dimensional shape to prevent play, the tip tool 10 can be manufactured at a low cost.

[0042] If the mounting fixture 96 is a clamp, the worker inserts the mounting hole 21 of the tip tool 10 into the protrusion of the clamp and presses the one-touch button. This causes the protrusion of the clamp to open and lock around the mounting hole 21, fixing the tip tool 10 to the spindle 92.

[0043] After fixing the tip tool 10 to the spindle section 92, the operator switches on the power tool 90 and oscillates the tip tool 10 at high speed. The engaging section 20 is made of a first metal plate 11 which is harder than conventional commercially available tip tools and is therefore less prone to deformation, so the power of the multi-tool is efficiently transmitted to the tip tool 10. In addition, the second locking corner 23 of the tip tool 10 locks into the ring section 95 at a position close to the blade section 32, so the play of the tip tool 10 is limited at a position close to the blade section 32, and the power of the multi-tool is transmitted to the blade section 32 even more efficiently.

[0044] Next, the worker applies the tip tool 10 to the concrete or other material and begins the scraping process. Because the blade portion 32 of the tip tool 10 is wide, it can be applied to a wide surface such as concrete, allowing for efficient scraping.

[0045] The blade portion 32 is made of a second metal plate 12 that is thicker than that of conventional commercially available tip tools 10, so it does not easily become thin even when cutting concrete. Therefore, the blade portion 32 has high durability when cutting concrete and the like. Also, even when using an auxiliary agent mainly composed of organic acids when cutting concrete and the like, the blade portion 32 is less likely to corrode or dissolve like conventional tip tools. Therefore, the blade portion 32 has high durability even when used with auxiliary agents. Furthermore, since the tip surface 33 of the blade portion 32 is a cut surface, it is possible to gain more working time before it becomes thin and sharp compared to conventional commercially available tip tools that are chamfered from the beginning. In this way, the blade portion 32 of the tip tool 10 is suitable for cutting concrete and the like.

[0046] By using a highly durable tip tool 10 when cutting concrete, the worker can reduce the frequency of replacing the tip tool 10, and perform the work of cutting and removing concrete efficiently.

[0047] <Example 2> Next, the tip tool 50 according to Embodiment 2, which embodies the present invention, will be described with reference to Figure 6. Figure 6(a) shows the tip tool 50 viewed from below in the Y-axis direction, and (b) shows a cross-sectional view of the tip tool 50. The tip tool 50 of this embodiment differs from Embodiment 1 in that the engaging portion 20, the tip portion 30, and the connecting portion 40 are made from a single metal plate 51. Components similar to those in Embodiment 1 are denoted by the same reference numerals, and redundant explanations are omitted.

[0048] The tip tool 50 in this embodiment, like in Embodiment 1, is made of metal and has an engaging portion 20, a tip portion 30, and a connecting portion 40. The engaging portion 20, the tip portion 30, and the connecting portion 40 are integrally formed from a single metal plate 51. The metal plate 51, like the second metal plate 12 in Embodiment 1, is thicker than the metal plate used in conventional general-purpose tip tools. As a result, the blade portion 32 of the tip tool 50 does not easily become thin even when cutting concrete, etc., as in Embodiment 1, and therefore the tip tool 50 has high durability.

[0049] The engaging portion 20 is flat, as in Embodiment 1, and has a first locking corner portion 22 of 4 and a second locking corner portion 23 of 2. The connecting portion 40 connects the engaging portion 20 and the tip portion 30, as in Embodiment 1, and has left and right side edges 41. The tip portion 30 has a blade portion 32, as in Embodiment 1. The blade portion 32 is trapezoidal, as in Embodiment 1, with its dimensions gradually increasing in the left-right direction from the connecting portion 40 side toward the tip surface 33, and the tip surface 33 is made of a cut surface.

[0050] In the tip tool 50 of this embodiment, as in Embodiment 1, when the tip tool 50 is fixed to the annular portion 95, the first locking angle portion 22 and the second locking angle portion 23 of the engaging portion 20 lock into the recess 97 of the annular portion 95, thereby fixing it to the annular portion 95 with limited play. Therefore, as in Embodiment 1, the tip tool 50 can be attached to the spindle portion 92 without play. Furthermore, the tip tool 50 can be manufactured more easily than when joining two metal plates, and as in Embodiment 1, the engaging portion 20 does not need to be formed into a three-dimensional shape, so it can be manufactured at low cost.

[0051] <Other examples> The present invention is not limited to the embodiments described above and in the drawings, and the following embodiments, for example, are also included in the technical scope of the present invention. (1) In the above embodiment, the engaging portion 20 has four first locking corners 22 and two second locking corners 23. However, the engaging portion 20 may be configured such that only the two first locking corners 22 are locked into the recess 97, as shown in Figure 7. In this case, both sides 24 of the first locking corners 22 are positioned along the surface 99 of the recess 97, and the two sides 24 and the two surface 99 are in close proximity or in contact with each other. The number of locking corners may be 3 to 5, or 7 or more. (2) In the above embodiment, both of the two sides 24 constituting the first locking corner 22 are close to or in contact with the surface 99 of the recess 97. However, the implementation is not limited to this, and only one of the two sides constituting the first locking corner may be brought close to or in contact with the surface 99 of the recess 97 to prevent the engaging portion from wobbling in the XZ plane relative to the annular portion 95. (3) In the above embodiment, all corners of the engaging portion 20 constitute either the first locking corner 22 or the second locking corner 23. However, the embodiment is not limited to this, and only some of the corners of the engaging portion may constitute locking corners. In other words, the engaging portion may have corners that do not engage with the recess of the annular portion. (4) In the above embodiment, the engaging portion 20 has a hexagonal shape. However, it is not limited to this, and the engaging portion may have any polygonal shape, such as a square, pentagon, heptagon, octagon, etc. (5) In the above embodiment, the engaging portion 20 has a second locking corner portion 23. However, the engaging portion 20 may have only a first locking corner portion 22. In other words, only the corner portion of the engaging portion may lock into the recess of the annular portion, and the connecting portion may not lock into the recess. (6) In the above embodiment, the tip surface 33 of the tip portion 30 is made of a cut surface. However, the tip surface of the tip portion may be chamfered. (7) In the above embodiment, the width dimension of the tip portion 30 is greater than the width dimension of the engaging portion 20. However, the width dimension of the tip portion may be smaller than the width dimension of the engaging portion. Furthermore, the shape of the tip portion does not necessarily have to be trapezoidal and may be changed according to the object, the material of the tip portion, the work content, etc. In some cases, the shape of the tip portion may be pointed or rounded. (8) In the above embodiment, the material, strength, hardness, and thickness dimensions of the first metal plate 11 and the second metal plate 12 have been described, but these may be changed as appropriate depending on the object. [Explanation of symbols]

[0052] 10,50...tip tool 11…First metal plate (metal plate constituting the engaging part) 12…Second metal plate (other metal plate) 20...Engaging part 21... Mounting hole section 22...First locking corner (locking corner) 23...Second locking corner (locking corner) 25...Connection part 30…Tip 33…Tip surface 40...Connection part 51…Metal plate (a single metal plate) 90...Power tools 92...Spindle section 95... Circular section 96…Mounting fasteners 97…recess

Claims

1. A tool tip that can be interchangeably attached to the spindle of an electric power tool, The spindle portion is provided with an annular portion in which a plurality of recesses are continuously and evenly formed around the entire circumference of the inner surface. The tip tool has a flat plate-shaped engaging portion that engages with the inside of the annular portion, a tip portion, and a connecting portion that connects the engaging portion and the tip portion. The engagement portion has a polygonal shape with multiple corners, and has a mounting hole for inserting a mounting fastener that is attached to the spindle portion, and at least two of the multiple corners are locked into the recess and engaged, the tip tool.

2. The tip tool according to claim 1, wherein the locking angle is formed in a connecting portion that connects the engaging portion and the connecting portion.

3. The tip tool according to claim 1 or 2, wherein the engaging portion, the tip portion, and the connecting portion are made of a single metal plate.

4. The tip tool according to claim 1 or 2, wherein the tip portion is made of another metal plate that has a greater thickness than the metal plate constituting the engaging portion.

5. The tip tool according to claim 4, wherein the hardness of the engaging portion is equal to or higher than the hardness of the tip portion.

6. The tip tool according to claim 1 or 2, wherein the tip surface of the tip portion is composed of a cut surface.

7. The tip tool according to claim 1 or 2, wherein the width dimension of the tip portion is greater than the width dimension of the engaging portion.

Images