JP7604185B2 - Portable processing machine - Google Patents

Description

The present invention relates to a portable processing machine for processing workpieces.

For example, a portable processing machine known as a portable circular saw has a tool body equipped with a tool tip driven by an electric motor as a drive source, and a base that supports the tool body. Cutting can be performed by placing the workpiece against the underside of the base and protruding the tool tip from the underside of the base to cut into the workpiece.

In conventional portable processing machines, aluminum bases have been widely used. Patent Document 1 describes an aluminum base that is nickel-plated. Nickel plating can increase the hardness of the base. It can also give the base a more luxurious appearance.

It has been desirable to make the base lighter in order to make portable processing machines lighter. To make the base lighter while maintaining the strength of conventional products, it has been considered to make the base out of magnesium. However, it has been difficult to nickel-plate a magnesium base in the past. For example, if the nickel plating or surface treatment prior to plating is uneven, the nickel plating tends to wear away easily. Furthermore, corrosion is likely to occur between the magnesium base and the nickel plating. It has been difficult to uniformly apply nickel plating or surface treatment to a base that has multiple protrusions or recesses.

JP 2001-315075 A

As mentioned above, there is room for improvement in the base of the portable processing machine. Therefore, there has been a demand for a portable processing machine with a lightweight, hard, and luxurious base.

According to one feature of the present disclosure, the portable processing machine has a tool body that houses an electric motor and supports a cutting tool that is rotated by the electric motor, and a base that supports the tool body with the cutting tool protruding downward and has a lower surface that is in contact with the workpiece. The base is made of magnesium and has a nickel-plated layer on its surface.

Therefore, by making the base out of magnesium, the base of the portable processing machine can be made lighter. Moreover, by applying nickel plating, a base with high hardness can be provided. Furthermore, by applying nickel plating, the exterior appearance of the base can be made more luxurious.

According to another feature of the present disclosure, the nickel plating layer has a thickness of 1/200 to 1/100 of the thickness of the base. Therefore, the nickel plating layer is provided thicker than a typical plating layer, which is approximately 1/200 or less of the thickness of the base. By providing a thick nickel plating layer, wear can be suppressed. In addition, by increasing the relative thickness of the nickel plating layer to the thickness of the base to increase the hardness, the strength of the base can be improved. Furthermore, corrosion between the nickel plating and the base can be prevented. In this way, the base can be maintained in a state of high hardness and a luxurious feel.

According to another feature of the present disclosure, the base has corners between the lower surface and the front and rear surfaces or the left and right side surfaces that stand adjacent to the lower surface. At least a portion of the corners has an arc-shaped cross section. Therefore, a region with an arc-shaped cross section is provided in the convex corner. Therefore, nickel plating can be applied approximately uniformly along the arc-shaped cross section at the corners. This makes it possible to suppress wear of the nickel plating at the corners. The corners are located at the edge of the lower surface that contacts the workpiece, and therefore are prone to wear. Therefore, wear of the nickel plating on the magnesium base can be suitably suppressed. Furthermore, corrosion between the nickel plating at the corners and the magnesium base can be suppressed.

According to another feature of the present disclosure, at least one of the four outer peripheral corners connecting the front and rear surfaces and the left and right side surfaces has an arc-shaped cross section in a plan view. At least one outer peripheral corner has a corner with at least a portion having an arc-shaped cross section at the lower end. Therefore, at least one outer peripheral corner has an arc-shaped cross section in the horizontal and vertical directions. Therefore, at least one outer peripheral corner is three-dimensionally rounded. Therefore, nickel plating can be applied to the outer peripheral corner approximately uniformly along the arc-shaped cross section in both the vertical and horizontal directions. This can suppress wear of the nickel plating at the outer peripheral corner and corrosion between the nickel plating and the magnesium base.

According to another feature of the present disclosure, the corner portion has an arc-shaped portion that is a curved surface with an arc-shaped cross section, and an inclined surface portion that is adjacent to the arc-shaped portion below the arc-shaped portion and has a linear cross section that is inclined relative to the lower surface. Therefore, the nickel plating layer is applied to the arc-shaped portion with a substantially uniform thickness. Also, when the lower portion of the base material (base molding) is removed to form the lower surface of the base, there may be variations in the thickness of the removed portion. Even in this case, the corner formed by the inclined surface portion and the lower surface can be formed with the same angle. Moreover, this corner can be formed with a blunt angle. Therefore, the thickness of the nickel plating layer is less likely to become thin at the corner formed by the inclined surface portion and the lower surface. Thus, the variation in the thickness of the nickel plating layer at the corner portion can be suppressed.

According to another feature of the present disclosure, the corners have curved surfaces with an arc-shaped cross section that connects the front and rear surfaces or the left and right side surfaces with an imaginary plane that is below the bottom surface and parallel to the bottom surface. Therefore, for the base material (base molded body) before the bottom surface is planed, the corners of the bottom end can be formed into a so-called rounded chamfered shape. This allows the corners of the base molded body to have a simple shape. This makes it easy to manufacture a mold for molding the base molded body.

According to another feature of the present disclosure, a recess is provided on the upper surface of the base. The recess is surrounded on its periphery by a vertical wall that stands up in the vertical direction. The vertical wall has a rounded portion that is curved when viewed from above. A tangent line that touches the rounded portion extends horizontally and parallel to the front and rear faces or the left and right side faces of the base. A straight line that is perpendicular to the tangent line and extends horizontally intersects the rounded portion at the end of the recess in the extension direction of the tangent line. The distance from the tangent line to the intersection where the straight line intersects with the rounded portion is longer than the vertical depth of the recess.

Therefore, by providing a relatively large rounded portion on the vertical wall in comparison to the depth of the recess, it is easy to drain the solvent, etc. from the recess by, for example, tilting the base. This makes it possible to prevent the solvent, etc. from accumulating in the recess. This allows the surface treatment to be performed approximately uniformly in the recess, and nickel plating to be performed approximately uniformly. This makes it possible to effectively prevent corrosion between the nickel plating and the magnesium base around the recess.

According to another feature of the present disclosure, the rounded portion is a curved shape sandwiched between two straight lines extending parallel to the front and rear surfaces or the left and right side surfaces when viewed from above. Therefore, the rounded portion is formed long between the two straight lines. Therefore, it is easy to preferably discharge solvents and the like from the recess through the rounded portion. This makes it possible to more preferably prevent solvents and the like from accumulating in the recess. Therefore, it is possible to apply a substantially uniform surface treatment to the recess, and also to apply a substantially uniform nickel plating. This makes it possible to preferably prevent corrosion between the nickel plating and the magnesium base around the recess.

According to another feature of the present disclosure, the recess has a bottom wall surrounded by a vertical wall, and a connecting region that connects the vertical wall and the bottom wall and has an arc-shaped cross section. This makes it possible to prevent solvents and the like from accumulating on the periphery of the bottom wall that connects to the vertical wall. This makes it possible to apply a substantially uniform surface treatment to the recess, and to apply a substantially uniform nickel plating. This makes it possible to prevent corrosion between the nickel plating in the recess and the base.

Another feature of the present disclosure relates to a method for manufacturing a base for a portable processing machine that supports a tool body and contacts a workpiece. The base molded body is plate-shaped and has edges between the bottom surface and the front and rear or left and right side surfaces that stand up adjacent to the bottom surface (the corners of the base molded body are referred to as "edges" to distinguish them from the corners of the base). A base molded body, at least a portion of whose edge has an arc-shaped cross section, is molded using a molding die using magnesium as a raw material. The bottom surface of the base molded body is flattened by planing. The surface of the base is nickel-plated.

Therefore, by making the base out of magnesium, the base can be made lightweight. Moreover, by applying nickel plating, a base with high hardness and a luxurious feel can be provided. Nickel plating can be applied almost uniformly to the edge portion, at least a part of which has an arc-shaped cross section. This makes it possible to suppress wear of the nickel plating at the edge portion and corrosion between the nickel plating and the magnesium base. In addition, an arc-shaped cross section can be left at the corners of the base after the bottom surface of the base molded body is planed. This makes it possible to both form the bottom surface of the base and perform a plating process to apply a nearly uniform nickel plating layer to the magnesium base.

According to another feature of the present disclosure, the edge has an arc-shaped cross section throughout the entire thickness direction. In the planing process, the lower portion of the arc-shaped cross section is removed and the upper portion is left. Therefore, nickel plating can be applied to the edge approximately uniformly along the arc-shaped cross section throughout the entire thickness direction. Although a corner is created at the lower end of the arc-shaped portion by the planing process, it is formed at a very blunt angle slightly less than 180°. Therefore, wear of the nickel plating at the corners of the base and corrosion between the nickel plating and the magnesium base can be effectively suppressed.

According to another feature of the present disclosure, the edge has an arc-shaped cross section at the top and a straight cross section below the arc-shaped cross section. In planing, the lower part or all of the straight cross section is planed. This makes it easy to adjust the amount of cutting when planing the bottom surface of the base molding. During mass production, there may be variations in the amount of cutting. Even in such cases, since the shape (inclination angle) of the inclined surface portion and the lower inclined surface portion is the same, the shapes after processing can be formed to be approximately the same.

According to another feature of the present disclosure, the base molding has a bulge that bulges downward from the edge from a region closer to the center than the edge and is cut off during planing. The base molding is therefore provided with a shape in which the convex shape of the bulge is spaced away from the edge. This allows the corners of the base after planing to be chamfered without any corners. This allows nickel plating to be applied approximately uniformly to the corners of the base so as to follow the cross-sectional arc shape.

1 is an overall perspective view of a portable processing machine according to a first embodiment; FIG. 2 is a perspective view of a base according to the first embodiment. FIG. FIG. 4 is a cross-sectional view taken along line VV in FIG. 3, and is a vertical cross-sectional view of the base. FIG. 5 is an enlarged side view of part VI in FIG. 4 . 4 is a plan view of a recess provided on the upper surface of the base. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7, and is a vertical cross-sectional view of the recess. FIG. 6 is an enlarged side view of a base according to a second embodiment, which corresponds to a portion VI in FIG. 4 . 13 is a plan view of a recess provided on the upper surface of a base according to a second embodiment. FIG. FIG. 6 is an enlarged side view of a base according to a third embodiment, corresponding to a portion VI in FIG. 4 . FIG. 13 is a plan view of a recess provided on the upper surface of the base according to the third embodiment. FIG. 13 is an enlarged side view of a base according to a fourth embodiment, corresponding to a portion VI in FIG. 4 . 13 is a plan view of a recess provided on the upper surface of a base according to a fourth embodiment; FIG. FIG. 4 is a vertical cross-sectional view that illustrates a plating layer at a chamfered portion having a flat chamfered shape. FIG. 4 is a vertical cross-sectional view that illustrates a plating layer at a chamfered portion having a rounded chamfered shape.

First Embodiment
Next, a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, the portable processing machine 1 of the first embodiment is called a portable circular saw, and has a tool body 10 and a rectangular flat-plate-shaped base 2 that supports the tool body 10. The tool body 10 rotatably supports a substantially disk-shaped cutting tool 11. The lower surface 2c (see FIG. 4) of the base 2 is formed in a flat shape and is abutted against the upper surface of the workpiece. The lower side of the cutting tool 11 can be protruded toward the lower surface 2c through a window portion 2a that penetrates the base 2 in the vertical direction. The cutting tool 11 protruded toward the lower surface 2c cuts into the workpiece to perform cutting processing. The tool body 10 is provided with a handle portion 30 that is held by a user. The user is positioned on the left side of the portable processing machine 1 in FIG. 1, holds the handle portion 30, and moves it to the right to proceed with cutting processing. In the following description, the front and rear directions of the members and components are defined as the direction in which the cutting process proceeds by moving the portable processing machine 1, and the rear direction is defined as the user side. The up, down, left and right directions of the members and components are defined based on the user.

As shown in FIG. 1, the tool body 10 is supported above the base 2 via a front tilt support 5 and a rear tilt support 6 (see FIG. 2). The front tilt support 5 is composed of a fan-shaped front angular plate 17 attached to the front of the base 2, and a bracket 18 connected integrally to the tool body 10. The front angular plate 17 stands upright and is attached to the base 2 so that the center of the arc of the fan shape is located in front of the cutting tool 11. The front tilt support 5 has a left-right tilt support shaft 8 that extends in the front-rear direction at approximately the center of the fan shape of the front angular plate 17.

As shown in FIG. 1, a vertical swing support shaft 7 extending in the left-right direction is provided at the rear of the front angular plate 17. The bracket 18 is connected to the front angular plate 17 so as to be able to swing vertically around the vertical swing support shaft 7. The tool body 10 connected to the bracket 18 can swing vertically around the vertical swing support shaft 7. By changing the vertical swing position of the tool body 10 relative to the base 2, the protrusion dimension of the cutting tool 11 toward the underside 2c of the base 2 can be changed. This makes it possible to adjust the cutting depth of the cutting tool 11 into the workpiece. The cutting depth of the cutting tool 11 can be adjusted using a depth guide 9 attached to the left side of the fixed cover 15, which will be described later.

As shown in FIG. 2, the rear tilt support 6 has a fan-shaped rear angular plate 2b that stands upward at the rear of the base 2. Unlike the front angular plate 17, the rear angular plate 2b is formed integrally with the base 2 by one-piece molding. The rear tilt support 6 has a left-right tilt support shaft 8 that extends in the front-rear direction at approximately the center of the fan shape of the rear angular plate 2b. The left-right tilt support shaft 8 of the rear tilt support 6 and the front tilt support 5 are coaxial. As shown in FIG. 1, the tool body 10 can be tilted left and right around the left-right tilt support shaft 8 of the front tilt support 5 and the rear tilt support 6. By tilting the tool body 10 left and right, it is possible to perform inclined cutting with the cutting tool 11 inclined relative to the underside 2c of the base 2.

As shown in FIG. 1, a fixed cover 15 is attached to the tool body 10, covering the upper half of the cutting tool 11. A white arrow 15a indicating the rotation direction of the cutting tool 11 is displayed on the right side of the fixed cover 15. A movable cover 16 is attached to the tool body 10, covering the lower half of the cutting tool 11. The movable cover 16 is supported so as to be openable and closable in the circumferential direction of the cutting tool 11 and is spring-biased in the closing direction (counterclockwise in FIG. 1). When the movable cover 16 is closed by the spring bias, it covers the lower half of the cutting tool 11. When the movable cover 16 is opened against the spring bias, the cutting edge of the cutting tool 11 is exposed. In normal cutting, the front end of the movable cover 16 is abutted against the end of the workpiece, and the portable processing machine 1 is moved forward in the abutting state, so that the movable cover 16 is gradually opened against the spring bias. An opening/closing lever 16a is provided on the right side of the movable cover 16. The user can grasp this opening/closing lever 16a to forcibly open and close the movable cover 16.

As shown in FIG. 1, a gear housing 22 is provided on the left side of the fixed cover 15. The gear housing 22 houses a reduction gear train (not shown). A motor housing 20 having a substantially cylindrical shape is provided on the left side of the gear housing 22. The motor housing 20 houses a motor 21 called a DC brushless motor. The rotation output of the motor shaft of the motor 21 is reduced through the reduction gear train housed in the gear housing 22 and transmitted to a spindle extending in the left-right direction. The right end side of the spindle protrudes into the fixed cover 15 and has a cutting tool 11 attached thereto. The cutting tool 11 is sandwiched between the outer flange 12 and an inner flange (not shown) in a direction perpendicular to the surface (left-right direction) in a position perpendicular to the spindle. The sandwiched state of the cutting tool 11 is locked by a fixing bolt 13 tightened to the tip of the spindle. As a result, the cutting tool 11 is fixed to the spindle so that it cannot be displaced in the axial direction and cannot be rotated around the axis.

As shown in FIG. 1, a handle portion 30 is provided on the upper part of the tool body 10. The front end of the handle portion 30 is connected to the motor housing 20 and the upper part of the gear housing 22. The handle portion 30 is formed in a loop shape extending rearward from its front end. The loop-shaped portion of the handle portion 30 is provided as a grip portion 31 that is held by the user when using the portable processing machine 1. A trigger-type switch lever 32 is provided on the inner periphery of the upper loop shape of the grip portion 31. When the switch lever 32 is pulled with the fingertips of the hand holding the grip portion 31, the motor 21 starts and the cutting tool 11 rotates. A lock-off button 33 that can be pressed is provided above the switch lever 32. By pressing the lock-off button 33, the locked state of the switch lever 32 is released and the switch lever 32 can be pulled. Therefore, the lock-off button 33 prevents the switch lever 32 from being pulled inadvertently.

The base 2 shown in Figures 3 and 4 is made of magnesium and formed using a molding die called a die-casting die. After forming, the bottom surface and the left and right side surfaces are flat-cut (planar cutting). The base 2 has a planar front surface 2d and a rear surface 2e that extend in the vertical direction at the front and rear ends of the approximately rectangular shape. The base 2 has a plate-shaped right side surface 2f and a left side surface 2g that stand up in the vertical direction at the left and right ends of the approximately rectangular shape. The front surface 2d, the rear surface 2e, the right side surface 2f, and the left side surface 2g are connected to the bottom surface 2c of the base 2 by chamfered portions 3 in which the corners are removed by an inclined plane or a rounded shape. Hereinafter, "chamfered" is used to mean both normal chamfering (planar chamfering) in which the corners are removed by an inclined plane, and rounded chamfering in which the corners are removed by a rounded shape. In addition, in the following, the chamfered portion is used to mean the corners of the base and the edge of the base molded body in this disclosure. The chamfered portion 3 is provided at the lower end of the front surface 2d, rear surface 2e, right side surface 2f, and left side surface 2g. The front surface 2d and the right side surface 2f or the left side surface 2g, and the rear surface 2e and the right side surface 2f or the left side surface 2g are connected to each other at the outer peripheral corners 3a, which correspond to the four corners of the approximately rectangular shape of the base 2. Therefore, the chamfered portion 3 is also provided at the lower end of the outer peripheral corners 3a. The lower surface 2c, the right side surface 2f, and the left side surface 2g are flat surfaces after planing. Also, when the outer peripheral corners 3a are viewed in a plan view, they have a cross-sectional arc shape with corners in which the outside of the roundness is cut out by a flat surface. This is because the rounded chamfer is formed at the outer peripheral corners in the state of the base molded body, and the right side surface 2f and the left side surface 2g of the base 2 are formed by removing the right side surface and the left side surface by planing from that state.

As shown in FIG. 6, the chamfered portion 3 has an arc-shaped portion 3b with a cross section of R1.0 and an inclined surface portion 3c with a cross section of a straight line inclined at approximately 45° with respect to the lower surface 2c. The arc-shaped portion 3b is provided on the upper part of the chamfered portion 3. The inclined surface portion 3c is provided on the lower part of the chamfered portion 3. The arc-shaped portion 3b and the inclined surface portion 3c are connected to each other so that the surface is smoothly continuous. More specifically, the straight line of the cross section of the inclined surface portion 3c is a tangent to the arc of the arc-shaped portion 3b. The arc-shaped portion 3b and the inclined surface portion 3c are formed so that the surface is smoothly continuous across the lower end of the front surface 2d (rear surface 2e), the lower end of the outer circumferential corner portion 3a, and the lower end of the right side surface 2f (left side surface 2g) in the horizontal direction. The chamfered portion (edge portion) 35a having the arc-shaped portion 3b and the inclined surface portion 3c is formed using a mold for molding the base molding body 35. Here, the base molding 35 shows the base 2 and the removal portion 3e that bulges downward from the lower surface 2c in a state where they are integrated together.

As shown in FIG. 6, the base molding 35 is planed from its lower end to a predetermined thickness so that the lower surface 2c is formed flat at a predetermined height in the vertical direction. The removed portion 3e at the lower end of the base molding 35 is planed from the base molding 35 by a milling machine or other machine tool. This causes the lower inclined surface portion 3d, which is the lower part of the inclined surface portion 3c, to be cut from the base 2. The inclination angle of the lower inclined surface portion 3d is the same as that of the inclined surface portion 3c, and the two are on the same plane. The thickness of the removed portion 3e is set within a range in which the arc-shaped portion 3b remains entirely on the base 2 side when the removed portion 3e is cut from the base molding 35.

As shown in FIG. 3, the upper surface 2h of the base 2 is provided with a number of recesses 4 that are concave downward. The recesses 4 are provided in an area that extends in the front-rear direction to the left of the window portion 2a and is located below the tool body portion 10 (see FIG. 1). In a plan view, the recesses 4 are formed in a generally rectangular shape that extends long in the front-rear direction and has arc-shaped corners. The multiple recesses 4 are provided in the same shape and are arranged at generally equal intervals in the front-rear and left-right directions.

As shown in Figures 5, 7, and 8, the recess 4 is surrounded on its periphery by vertical walls 4a that stand up in the vertical direction. The vertical walls 4a have arc-shaped rounded portions 4b in a plan view at the four corners of the approximately rectangular shape. The radius of the four rounded portions 4b corresponds to the distance T shown in Figure 7. Distance T is calculated as shown below. Tangent line L1 extends in the front-rear direction and touches one of the rounded portions 4b. Tangent line L2 extends in the left-right direction perpendicular to tangent line L1 and touches the same rounded portion 4b. Distance T is the distance between tangent line L1 and the intersection point P where tangent line L2 touches rounded portion 4b.

As shown in Figures 5 and 8, the recess 4 has a bottom wall 4c surrounded by vertical walls 4a. The bottom wall 4c extends in a horizontal direction parallel to the lower surface 2c and is formed in a flat shape. The bottom wall 4c is formed at a depth D from the upper surface 2h. The depth D of the recess 4 is smaller than the above-mentioned distance T (see Figure 7). Therefore, the recess 4 has a shallow bottom shape in which the vertical depth is smaller than the horizontal length. The connection region 4d where the bottom wall 4c and the vertical wall 4a are connected is formed in an arc-shaped cross section. The connection region 4e where the vertical wall 4a and the upper surface 2h of the recess 4 intersect is also formed in an arc-shaped cross section. Here, the connection region has an arc-shaped cross section with R1.0.

The base 2 shown in FIG. 2 is first formed by die casting using magnesium as the raw material and a mold. As shown in FIG. 6, the base molded body 35 is planed so that the bottom surface 2c is a flat shape extending horizontally. The right side surface 2f and the left side surface 2g are also planed so that they are flat shapes extending vertically. This removes the removal portion 3e that bulges downward from the base molded body 35. After planing, a solvent for undercoating is applied to the surface of the base 2 as a undercoating treatment to improve the adhesion of plating. After the solvent that has accumulated on the surface of the base 2 is removed, the surface of the base 2 is nickel plated. This provides a nickel plating layer that covers the surface of the base 2.

The base 2 shown in FIG. 5 is formed so that the thickness N is approximately 2 mm. Specifically, the thickness of the base molded body 35 (see FIG. 6) is approximately 2.5 mm, with the removed portion 3e being removed by 0.5 mm. The thickness of the nickel plating layer provided on the surface of the base 2 is 10 μm or more, and preferably 10 to 20 μm. Therefore, the thickness of the nickel plating layer is 1/200 or more of the thickness N of the base 2, and preferably 1/200 to 1/100 of the thickness N of the base 2.

The thickness of the nickel plating layer at the chamfered portion will be explained with reference to Figures 15 and 16. As shown in Figure 15, the edge of the lower end of the base 70 is provided with a chamfered portion 71, which is a flat chamfer with the corners removed by an inclined plane. The base molding 76 of the base 70 has a chamfered portion (edge portion) 76a, whose edge at the lower end is flat chamfered. The lower surface 72 is formed by flat-cutting a removal portion 73 of a predetermined thickness from the lower end of the base molding 76. Then, a nickel plating layer is applied to the surface of the base 70. The plating layer 74 has a roughly constant thickness on the lower surface 72, front and rear surfaces, and left and right side surfaces of the base 70. However, the chamfered portion 71 has protruding corners at both the top and bottom ends. And it is difficult to plate on the corners 75 of this chamfered portion 71. This is because the nickel plating layer is a solidified liquid solution, and due to the nature of the liquid, the layer of the solution is parallel to the flat surface of the base 70, but the surface of the liquid is unlikely to become an edge at the corners 75. This can result in a thinner plating layer 74 at the chamfered portion 71. Therefore, it is difficult to adequately suppress wear and corrosion around the chamfered portion 71.

As shown in FIG. 16, the edge of the lower end of the base 80 is provided with a chamfered portion 81 that has a cross-sectional arc shape and has rounded chamfered corners. The chamfered portion 86 of the base molding 85 of the base 80 has a rounded chamfered shape on the upper side and a flat chamfered shape that is chamfered with an inclined flat surface below the rounded chamfered shape. The lower surface 82 is formed by flat-cutting a removal portion 83 of the same thickness as the flat chamfered shape from the lower end of the base molding 85. Therefore, the chamfered portion 81 of the cross-sectional arc shape is smoothly connected to the lower surface 82, the front and rear surfaces, and the left and right sides after flat-cutting. Therefore, the lower end of the base 80 is provided without having an angular shape like the corner 75 (see FIG. 15). Therefore, the plating layer 84 applied to the surface of the base 80 is provided with a generally constant thickness on the chamfered portion 81, the lower surface 82, the front and rear surfaces, and the left and right sides of the base 80. As a result, the chamfered portion 81 is protected from wear and corrosion by the plating layer 84, just like other parts of the base 80.

As described above, the portable processing machine 1 has a tool body 10 that houses a motor 21 and supports a cutting tool 11 that is rotated by the motor 21, as shown in FIG. 1, and a base 2 that supports the tool body 10 with the cutting tool 11 protruding downward and has a bottom surface 2c that abuts against the workpiece. The base 2 is made of magnesium and has a nickel-plated layer on its surface.

Therefore, by making the base 2 of the portable processing machine 1 out of magnesium, the base 2 can be made lightweight. Moreover, by applying nickel plating, the base 2 can be made to have high hardness. Furthermore, by applying nickel plating, the exterior of the base 2 can be made to have a luxurious feel.

As shown in FIG. 5, the nickel plating layer has a thickness of 1/200 to 1/100 of the thickness N of the base 2. Therefore, the nickel plating layer is provided thicker than typical plating layers, which are approximately 1/200 or less of the thickness N of the base 2. By providing a thick nickel plating layer, wear can be suppressed. Also, by increasing the relative thickness of the nickel plating layer to the thickness N of the base 2 to increase the hardness, the strength of the base 2 can be improved. Furthermore, corrosion between the nickel plating and the base 2 can be prevented. In this way, the base 2 can be maintained in a state of high hardness and a luxurious feel.

As shown in Figures 2 and 6, the base 2 has a chamfered portion 3 between the lower surface 2c and the front and rear surfaces 2d, 2e or the left and right side surfaces 2f, 2g that stand adjacent to the lower surface 2c. The upper part of the chamfered portion 3 is an arc-shaped portion 3b having an arc-shaped cross section. Therefore, the arc-shaped portion 3b having an arc-shaped cross section is provided on the convex chamfered portion 3. Therefore, nickel plating or surface treatment can be applied to the chamfered portion 3 approximately uniformly along the arc-shaped cross section of the arc-shaped portion 3b. This makes it possible to suppress wear of the nickel plating on the chamfered portion 3. The chamfered portion 3 is located at the edge of the lower surface 2c that contacts the workpiece, so wear is likely to occur. Therefore, wear of the nickel plating on the magnesium base 2 can be suitably suppressed. Furthermore, corrosion between the nickel plating on the chamfered portion 3 and the magnesium base 2 can be suppressed.

As shown in Figures 3, 4, and 6, the four outer peripheral corners 3a connecting the front and rear surfaces 2d, 2e and the left and right side surfaces 2f, 2g, respectively, have a cross-sectional arc shape with corners as described above in a plan view. At the lower end of the outer peripheral corners 3a, a chamfered portion 3 having an arc-shaped portion 3b with an arc-shaped cross section is located. Therefore, the outer peripheral corners 3a have an arc-shaped cross section in the horizontal direction and the up-down direction. Therefore, the outer peripheral corners 3a are three-dimensionally rounded. Therefore, the outer peripheral corners 3a can be nickel-plated or surface-treated before nickel treatment and can be applied to the outer peripheral corners 3a approximately uniformly along the cross-sectional arc shape in both the up-down direction and the horizontal direction. This can suppress wear of the nickel plating at the outer peripheral corners 3a and corrosion between the nickel plating and the magnesium base 2.

As shown in FIG. 6, the chamfered portion 3 has an arc-shaped portion 3b, which is a curved surface having an arc-shaped cross section, and an inclined surface portion 3c, which is adjacent to the arc-shaped portion 3b below the arc-shaped portion 3b and has a linear cross section that is inclined relative to the lower surface 2c. Therefore, the nickel plating layer is applied to the arc-shaped portion 3b with a substantially uniform thickness. Also, when the lower portion of the base molding 35 is removed to form the lower surface 2c, the thickness of the removed portion 3e may vary. Even in this case, the corner formed by the inclined surface portion 3c and the lower surface 2c can be formed with the same angle. Moreover, this corner can be formed with a blunt angle. Therefore, the thickness of the nickel plating layer is less likely to become thin at the corner formed by the inclined surface portion 3c and the lower surface 2c. Thus, the variation in the thickness of the nickel plating layer at the chamfered portion 3 can be suppressed.

As shown in FIG. 7, a recess 4 is provided on the upper surface 2h of the base 2. The recess 4 is surrounded by a vertical wall 4a that stands up in the vertical direction. The vertical wall 4a has a rounded portion 4b that is curved when viewed from above. Here, the length of the recess 4 in the front-rear direction is 25 mm, and the length in the left-right direction is 15 mm. The rounded portion 4b is a rounded chamfer with an R of 6.0. A tangent line L1 that touches the rounded portion 4b extends in the front-rear direction parallel to the left and right side surfaces 2f, 2g (see FIG. 3) of the base 2 and extends horizontally. A tangent line L2 that is perpendicular to the tangent line L and extends horizontally intersects with the rounded portion 4b at the end of the recess 4 in the extension direction of the tangent line L1. The distance from the tangent line L1 to the intersection point P where the tangent line L2 intersects with the rounded portion 4b is longer than the vertical depth D of the recess 4 (see FIG. 8). Here, the depth D is 5 mm and the distance T is 6 mm.

Therefore, by providing the vertical wall 4a with a relatively large rounded portion 4b in comparison with the depth D of the recess 4, for example by tilting the base 2, it is easy to drain the solvent etc. from the recess 4. This makes it possible to prevent the solvent etc. from accumulating in the recess 4. This allows the surface treatment to be performed approximately uniformly in the recess 4, and the nickel plating to be performed approximately uniformly. This makes it possible to effectively prevent corrosion between the nickel plating around the recess 4 and the magnesium base 2.

As shown in Figures 5 and 8, the recess 4 has a bottom wall 4c surrounded by a vertical wall 4a, and a connecting region 4d that connects the vertical wall 4a and the bottom wall 4c and has an arc-shaped cross section. This prevents solvents and the like from accumulating in the connecting region 4d. This allows the recess 4 to be subjected to a substantially uniform surface treatment and nickel plating to be substantially uniform. This prevents corrosion between the nickel plating in the recess 4 and the base 2. Here, the connecting region 4d has an arc-shaped cross section with an R of 1.0.

As shown in Figures 2 and 6, the base molding 35 is plate-shaped and has a chamfered portion 35a between the bottom surface 2c and the front and rear surfaces 2d, 2e or the left and right side surfaces 2f, 2g, which stand up adjacent to the bottom surface 2c. The base molding 35, in which the arc-shaped portion 3b of the chamfered portion 35a has an arc-shaped cross section, is molded using a molding die with magnesium as the raw material. The bottom surface of the base molding 35 is flattened by planing. The surface of the base 2 is nickel-plated.

Therefore, by making the base 2 out of magnesium, the base 2 can be made lightweight. Moreover, by applying nickel plating, the base 2 can be made to have high hardness and a luxurious feel. Nickel plating can be applied almost uniformly to the chamfered portion 3, whose arc-shaped portion 3b has an arc-shaped cross section. This can suppress wear of the nickel plating at the chamfered portion 3 and corrosion between the nickel plating and the magnesium base 2. In addition, the arc-shaped portion 3b can be left on the base 2 at the chamfered portion 3 after the bottom surface of the base molding 35 is planed. This can achieve both the formation of the bottom surface 2c of the base 2 and the plating process of applying a nearly uniform nickel plating layer to the magnesium base 2.

As shown in FIG. 6, the chamfered portion 3 has an arc-shaped portion 3b with an arc-shaped cross section on the upper side, and an inclined surface portion 3c with a linear cross section below the arc-shaped cross section. In planing, the lower inclined surface portion 3d below the inclined surface portion 3c is planed. Therefore, it is easy to adjust the amount of cutting when planing the lower surface of the base molding 35. For example, what was intended to be cut with an allowance of 0.5 mm may end up being 0.6 mm or 0.4 mm due to variations during mass production. Even in such cases, since the shapes (inclination angle) of the inclined surface portion 3c and the lower inclined surface portion 3d are the same, the shapes after processing can be formed to be approximately the same.

Second Embodiment
Next, a second embodiment of the present disclosure will be described with reference to Figures 9 and 10. In the following description, a portable processing machine 40 of the second embodiment will be described in detail only in terms of configurations that differ from the portable processing machine 1 of the first embodiment. As shown in Figure 9, the portable processing machine 40 has a base 41 equipped with a chamfered portion 42 having a shape different from the chamfered portion 3 (see Figure 6) of the portable processing machine 1. As shown in Figure 10, the base 41 has a recess 43 having a shape different from the recess 4 (see Figure 7) of the portable processing machine 1.

As shown in FIG. 9, the chamfered portion 42 is provided at the lower end of the front surface 41b where the lower surface 41a and the front surface 41b of the base 41 are connected, and at the lower end of the right side surface 41c where the lower surface 41a and the right side surface 41c are connected. The chamfered portion 42 is also provided at the lower end of the outer peripheral corner 42a where the front surface 41b and the right side surface 41c are connected to each other. Although not visible in the figure, the rear surface and the left side surface of the base 41 are similarly provided with chamfered portions 42 at their lower ends.

As shown in FIG. 9, the chamfered portion 42 has an arc-shaped portion 42b with a cross section of R1.0. The base molding body 45 before the base 41 is planed includes a removal portion 42d that bulges downward from the lower surface 41a. The arc-shaped portion 42b is formed so as to smoothly connect the front surface 41b or the right side surface 41c to the lower surface of the removal portion 42d with an arc-shaped cross section. In other words, the arc-shaped portion 42b has a curved shape that connects the front surface 41b or the right side surface 41c to a virtual plane 42e that is parallel to the lower surface 41a below the lower surface 41a with an arc-shaped cross section. The arc-shaped portion 42b is formed so that the surface is smoothly continuous across the lower end portions of the front surface 41b, the outer circumferential corner portion 42a, and the right side surface 41c in the horizontal direction. The arc-shaped portion 42b is formed using a mold that molds the base molding body 45. When the removed portion 42d is cut, the lower arc-shaped portion 42c, which is the lower part of the arc-shaped portion 42b, is cut from the base 41. The thickness of the removed portion 42d is set so that at least a portion of the arc-shaped portion 42b is entirely within the range on the base 41 side.

As shown in FIG. 10, the upper surface of the base 41 is provided with a recess 43 that is concave downward. Similar to the recess 4 (see FIG. 3), multiple recesses 43 are provided and are arranged at approximately the same position as the recess 4. The recess 43 is formed by joining two arcs of equal diameter in a plan view with the concave sides facing each other, making the distance connecting the point where the two arcs are joined (intersection point P) longer than the distance between the two arcs (twice the distance T), and forming a straight line connecting the joining points along the front-rear direction. Here, the front-rear length of the recess 43 (the distance from line L4 to line L5 described later) is 25 mm, and the left-right length is 15 mm. The distance T is 7.5 mm.

As shown in FIG. 10, the recess 43 is surrounded by a vertical wall 43a that stands up in the vertical direction. The vertical wall 43a is an arc shape in a plan view and is composed of a pair of rounded portions 43b on the left and right. The tangent line L1 extends in the front-rear direction and is tangent to one of the rounded portions 43b. The straight line L4 extends in the left-right direction perpendicular to the tangent line L1 and intersects with the front end of the same rounded portion 43b at an intersection P. A rounded chamfer of R1.0 is formed at the intersection P. The straight line L5 extends parallel to the straight line L4 at a position opposite the straight line L4 across the recess 43 and intersects with the rear end of the same rounded portion 43b. The rounded portion 43b is formed in a curved shape sandwiched between the straight lines L4 and L5. The rounded portion 43b is an arc shape with a radius of 15 mm.

As shown in FIG. 10, the recess 43 has a planar bottom wall 43c surrounded by vertical walls 43a. The cross-sectional view of the recess 43 taken along line A-A in FIG. 10 has a shape similar to the cross-sectional view of the recess 4 shown in FIG. 8. Therefore, the bottom wall 43c is formed at a depth D relative to the upper surface of the base 41. The depth D of the recess 43 is smaller than the distance T described above. The bottom wall 43c and the vertical walls 43a are connected to each other by a connecting region having an arc-shaped cross section.

As described above, the upper surface of the base 41 of the portable processing machine 40 is provided with a recess 43 as shown in FIG. 10. The rounded portion 43b of the vertical wall 43a of the recess 43 is a curved shape sandwiched between two tangent lines L1 and L3 that extend parallel to each other when viewed from above and are in contact with the rounded portion 43b. Therefore, the rounded portion 43b is formed long between the two tangent lines L1 and L3. Therefore, it is easy to preferably discharge the solvent, etc. from the recess 43 through the rounded portion 43b. This makes it possible to more preferably prevent the solvent, etc. from accumulating in the recess 43. Therefore, the surface treatment can be performed approximately uniformly in the recess 43, and the nickel plating can be performed approximately uniformly. This makes it possible to preferably prevent corrosion between the nickel plating around the recess 43 and the magnesium base 41.

As shown in FIG. 9, the chamfered portion 42 has a curved surface with an arc-shaped cross section that connects the front surface 41b or the right side surface 41c with the imaginary plane 42e. The imaginary plane 42e is parallel to the lower surface 41a below the lower surface 41a. Therefore, for the base molding body 45 of the base 41 before the lower surface 41a is planed, the chamfered portion (edge) 45a at the lower end can be formed into a so-called rounded chamfered shape. This allows the chamfered portion 45a of the base molding body 45 to have a simple shape. This makes it easy to manufacture a mold for molding the base molding body 45.

As shown in FIG. 9, the chamfered portion 42 has an arc-shaped portion 42b that has an arc-shaped cross section throughout the thickness of the base 41. In the planing process, the lower arc-shaped portion 42c of the lower part of the arc-shaped portion 42b is removed, leaving the upper part. Therefore, nickel plating can be applied to the chamfered portion 42 almost uniformly so as to follow the arc-shaped cross section of the chamfered portion 42 throughout the thickness. Although a corner is created at the lower end of the arc-shaped portion 42b by planing, it is formed at a very blunt angle that is slightly smaller than 180°. As a result, even at the corner, the plating film thickness is not likely to become thin. Therefore, wear of the nickel plating in the chamfered portion 42 and corrosion between the nickel plating and the magnesium base 41 can be effectively suppressed.

Third Embodiment
Next, a third embodiment of the present disclosure will be described with reference to Figures 11 and 12. In the following description, a portable processing machine 50 of the third embodiment will be described in detail only in terms of configurations that differ from the portable processing machine 1 of the first embodiment. As shown in Figure 11, the portable processing machine 50 has a base 51 equipped with a chamfered portion 52 having a shape different from the chamfered portion 3 (see Figure 6) of the portable processing machine 1. As shown in Figure 12, the base 51 has a recess 53 having a shape different from the recess 4 (see Figure 7) of the portable processing machine 1.

As shown in FIG. 11, chamfered portions 52 are provided at the lower end of the front surface 51b where the lower surface 51a and the front surface 51b of the base 51 are connected, and at the lower end of the right side surface 51c where the lower surface 51a and the right side surface 51c are connected. Chamfered portions 52 are also provided at the lower end of the outer peripheral corner 52a where the front surface 51b and the right side surface 51c are connected to each other. Although not visible in the figure, chamfered portions 52 are also provided at the lower ends of the rear surface and the left side surface of the base 51.

As shown in FIG. 11, the chamfered portion 52 has an arc-shaped portion 52b with a cross section of R1.0. The base molding body 55 before the base 51 is planed has a removed portion (bulging portion) 52c that bulges downward from the lower surface 51a. The removed portion 52c is provided in an area closer to the center of the base 51 than the chamfered portion 52. The arc-shaped portion 52b is formed so that the surface is smoothly continuous across the lower end portions of the front surface 51b, the outer peripheral corner portion 52a, and the right side surface 51c in the horizontal direction. The arc-shaped portion 52b is formed using a mold that molds the base molding body 55. When the removed portion 52c is cut, the entire arc-shaped portion 52b remains on the base 51 side. The arc-shaped portion 52b is finished into a shape that smoothly connects the front surface 51b or the right side surface 51c to the lower surface 51a with a cross section of an arc.

12, the upper surface of the base 51 is provided with a recess 53 that is concave downward. The recess 53 is provided in a plurality of recesses 53, similar to the recess 4 (see FIG. 3), and is arranged at approximately the same position as the recess 4. The recess 53 is formed in an approximately rectangular shape that extends long in the front-rear direction in a plan view and has a front and rear part connected by a semicircular shape. The recess 53 is 25 mm long in the front-rear direction and 15 mm long in the left-right direction. The recess 53 is surrounded by a vertical wall 53a that stands upright in the up-down direction. The vertical wall 53a has a semicircular rounded portion 53b at the front and rear parts in a plan view. The tangent line L1 extends in the front-rear direction, and the tangent line L2 extends in the left-right direction perpendicular to the tangent line L1, and each of them is in contact with the same rounded portion 53b. The tangent line L3 extends parallel to the tangent line L1 at a position opposite the tangent line L1 across the recess 53, and is in contact with the same rounded portion 53b. Rounded portion 53b is formed as a curved line sandwiched between tangent line L1 and tangent line L3. Therefore, the radius of rounded portion 52b is 7.5 mm. The radius of rounded portion 53b corresponds to the distance T (7.5 mm) between tangent line L1 and the intersection point P where tangent line L2 meets rounded portion 53b.

As shown in FIG. 12, recess 53 has a planar bottom wall 53c surrounded by vertical walls 53a. The cross-sectional view of recess 53 taken along line A-A in FIG. 12 has the same shape as the cross-sectional view of recess 4 shown in FIG. 8. Therefore, bottom wall 53c is formed at a depth D relative to the upper surface of base 51. Depth D of recess 53 is 5 mm, which is smaller than the distance T mentioned above. Bottom wall 53c and vertical wall 53a are connected to each other by a connecting region having an arc-shaped cross section.

As described above, the base molding 55 for the base 51 has a removed portion 52c that bulges downward from the chamfered portion (edge portion) 55a from an area closer to the center of the base 51 than the chamfered portion 55a as shown in FIG. 11 and is cut off during planing. Therefore, the base molding 55 is provided with a shape in which the convex shape of the removed portion 52c is spaced away from the chamfered portion 55a. As a result, a rounded chamfer without corners can be formed on the chamfered portion 52 of the base 51 after planing. This allows nickel plating to be applied approximately uniformly to the chamfered portion 52 along the arc-shaped portion 52b of the cross-sectional arc shape.

Fourth Embodiment
Next, a fourth embodiment of the present disclosure will be described with reference to Figures 13 and 14. In the following description, a portable processing machine 60 of the fourth embodiment will be described in detail only in terms of configurations that differ from the portable processing machine 1 of the first embodiment. As shown in Figure 13, the portable processing machine 60 has a base 61 equipped with a chamfered portion 62 having a shape different from the chamfered portion 3 (see Figure 6) of the portable processing machine 1. As shown in Figure 14, the base 61 has a recess 63 having a shape different from the recess 4 (see Figure 7) of the portable processing machine 1.

As shown in FIG. 13, the chamfered portion 62 is provided at the lower end of the front surface 61b where the lower surface 61a and the front surface 61b of the base 61 are connected, and at the lower end of the right side surface 61c where the lower surface 61a and the right side surface 61c are connected. The chamfered portion 62 is also provided at the lower end of the outer circumferential corner 62a where the front surface 61b and the right side surface 61c are connected to each other. Although not visible in the figure, the rear surface and the left side surface of the base 61 are also provided with chamfered portions 62 at their lower ends in a similar manner.

As shown in FIG. 13, the chamfered portion 62 has an inclined surface portion 62b at the top that is linear in cross section and inclined at approximately 45° to the lower surface 61a, and an arc-shaped portion 62c at the bottom that has an arc-shaped cross section and an R1.0. The inclined surface portion 62b is formed using a molding die that molds the base molded body. The arc-shaped portion 62c is formed into an arc-shaped cross section by cutting when the lower surface 61a is formed into a flat surface by flat cutting. The arc-shaped portion 62c smoothly connects the front surface 61b or the right side surface 61c to the lower surface 61a with an arc-shaped cross section.

As shown in FIG. 14, the upper surface of the base 61 is provided with a recess 63 that is concave downward. The recess 63 is provided in a plurality of recesses 63, similar to the recess 4 (see FIG. 3), and is arranged at approximately the same position as the recess 4. The length of the recess 63 in the front-rear direction is 25 mm, and the length in the left-right direction is 15 mm. The recess 63 is formed in an elliptical shape that is long in the front-rear direction in a plan view. This ellipse is defined by a major axis of 25 mm and a minor axis of 15 mm. The periphery of the recess 63 is surrounded by a vertical wall 63a that stands up in the up-down direction. The vertical wall 63a has a rounded portion 63b that is elliptical in a plan view. The tangent line L1 extends in the front-rear direction, and the tangent line L2 extends in the left-right direction perpendicular to the tangent line L1, and each of them is in contact with the rounded portion 63b. The tangent line L3 extends parallel to the tangent line L1 at a position opposite the tangent line L1 across the recess 63, and is in contact with the rounded portion 63b. Rounded portion 63b is formed as a curved line sandwiched between tangent line L1 and tangent line L3. The minor axis of rounded portion 63b corresponds to the distance T between tangent line L1 and the intersection point P where tangent line L2 meets rounded portion 63b. Here, distance T is half the minor axis, so it is 7.5 mm.

As shown in FIG. 14, the recess 63 has a planar bottom wall 63c surrounded by a vertical wall 63a. The cross-sectional view of the recess 63 taken along line A-A in FIG. 14 has a shape similar to the cross-sectional view of the recess 4 shown in FIG. 8. Therefore, the bottom wall 63c is formed at a depth D relative to the upper surface of the base 61. The depth D of the recess 63 is 5 mm, which is smaller than the distance T mentioned above. The bottom wall 63c and the vertical wall 63a are connected to each other by a connecting region having an arc-shaped cross section.

<Other Modifications>
Various modifications can be made to the portable processing machines 1, 40, 50, and 60 of the first to fourth embodiments described above. Although a portable processing machine called a portable circular saw has been exemplified, the present invention can be applied to other portable processing machines such as a jigsaw, a router, and a portable planer. A magnesium base is exemplified with a nickel plating layer having a thickness of 1/200 to 1/100 of the thickness N of the base. Alternatively, an aluminum base may be exemplified with a nickel plating layer having a thickness of 1/200 to 1/100 of the thickness N of the base. By applying a nickel plating layer thicker than the conventional plating layer, wear of the nickel plating can be suppressed, and further corrosion between the nickel plating and the aluminum base can be suppressed.

The arc-shaped portion of the chamfer may be provided during die-casting, or may be provided when machining the base. Although an arc-shaped portion of the chamfer has been exemplified as an easily shaped cross-section (a so-called R-shape), the cross-section may also be an elliptical shape, for example. The arc-shaped portion of the chamfer may be formed with a larger diameter at the front of the base, which is more likely to come into contact with the workpiece, and with a smaller diameter at the rear of the base. The inclined surface portion of the chamfer is exemplified as an inclined surface (a so-called C-surface) that is inclined at 45° to the bottom surface for easy shaping. Alternatively, the present invention can be applied to cases where the inclination angle to the bottom surface is smaller or larger than 45°, for example.

The recesses provided on the upper surface of the base may have a shape with a longitudinal direction in the left-right direction, for example. Multiple recesses may be formed with different shapes, or some of them may be formed with different sizes, or some of them may be formed with different sizes. Multiple recesses may be arranged in a zigzag pattern in the left-right direction, for example, or may be arranged irregularly, for example.

1... Portable processing machine 2... Base, 2a... Window, 2b... Rear angular plate, 2c... Lower surface 2d... Front, 2e... Rear, 2f... Right side, 2g... Left side, 2h... Top surface 3... Chamfered part (corner), 3a...outer corner, 3b...arc shape shaped part, 3c... inclined surface part 3d... lower inclined surface part, 3e... removed part 4... recessed part, 4a... vertical wall, 4b... rounded part, 4c... bottom wall, 4d, 4e... connecting region 5... front tilting support part 6 …Rear side tilting support part 7…Vertical swinging support shaft 8…Right and left tilting support shaft 9… Depth guide 10... tool body 11... cutting tool 12... outer flange 13... fixing bolt 15... fixed cover, 15a... white arrow (indicating the rotation direction of the cutting tool) 16... movable cover, 16a... opening/closing lever 17... front angular plate 18... bracket 20... motor housing 21... motor 22... gear housing 30... handle portion 31... grip portion 32... switch lever 33... lock-off button 35... base molded body, 35a... chamfered portion (edge portion)
40...Portable processing machine (second embodiment)
41: base; 41a: lower surface; 41b: front surface; 41c: right side surface; 42: chamfered portion (corner); 42a: outer peripheral corner; 42b: arc-shaped portion; 42c: lower arc-shaped portion; 42d: removed portion; 42e: Imaginary plane 43: recess, 43a: vertical wall, 43b: rounded portion, 43c: bottom wall 45: base molding body, 45a: chamfered portion (edge portion)
50...Portable processing machine (third embodiment)
51...Base 51a...Bottom surface, 51b...Front surface, 51c...Right side 52...Chamfered portion (corner), 52a...Outer periphery corner portion, 52b...Circular shaped portion 52c...Removed portion (bulging portion)
53: Recess, 53a: Vertical wall, 53b: Rounded portion, 53c: Bottom wall 55: Base molding body, 55a: Chamfered portion (edge portion)
60...Portable processing machine (fourth embodiment)
61: Base 61a: Lower surface, 61b: Front surface, 61c: Right side surface 62: Chamfered portion (corner portion), 62a: Outer peripheral corner portion, 62b: Inclined surface portion, 62c: Arc-shaped portion 63: Recessed portion, 63a: Vertical wall, 63b ...rounded portion, 53c...bottom wall 70...base, 71...chamfered portion (corner), 72...lower surface, 73...removed portion, 74...plating layer 75...corner 76...base molding, 76a...chamfered portion (edge Department)
80: base; 81: chamfered portion (corner); 82: lower surface; 83: removed portion; 84: plating layer; 85: base molded body; 86: chamfered portion (edge);
D...Depth L1, L2, L3...Tangent line (straight line), L4, L5...Straight line P...Intersection point,
T: Distance N: Thickness

Claims (13)

A portable processing machine,
A tool body that houses an electric motor and supports a cutting tool that is rotated by the electric motor;
a base having a lower surface that supports the tool body and is brought into contact with a workpiece in a state in which the cutting tool is protruded downward;
the base is made of magnesium and has a nickel-plated layer on its surface;
the base has a curved surface having an arc-shaped cross section, and extends in an arc shape in a side view from the bottom surface directly or away from the bottom surface toward the front surface, the rear surface, the right side surface, and the left side surface of the base, and has an arc-shaped portion with a radius of 50% or more of a wall thickness of the base,
The arc-shaped portion has a nickel-plated layer of a substantially uniform thickness on its surface. 2. The portable processing machine according to claim 1,
The arc-shaped portion has an arc shape with a central angle of 30° or more when viewed from the side . The portable processing machine according to claim 1 or 2,
The arc-shaped portion extends directly from the bottom surface toward each of the front surface, the rear surface, the right side surface, and the left side surface. The portable processing machine according to any one of claims 1 to 3,
The thickness of the nickel plating layer is 1/200 to 1/100 of the thickness of the base. A portable processing machine according to any one of claims 1 to 4,
A portable processing machine in which at least one of four connecting parts interconnecting the front, rear, right side, and left side of the base is arc-shaped in a planar view, and the arc-shaped part is located at the lower end of the four connecting parts. The portable processing machine according to any one of claims 1 to 5,
A portable processing machine in which an inclined surface portion having a linear cross section is provided between the lower surface and the arc-shaped portion, extending from the arc-shaped portion at an angle tangent to the arc-shaped portion and connecting to the lower surface. A portable processing machine according to any one of claims 1 to 6,
A recess is provided on an upper surface of the base,
The recess is surrounded by a vertical wall that stands upright in the vertical direction.
The vertical wall has a rounded portion that is curved when viewed from above,
A portable processing machine in which the overall length and width of the rounded portion are greater than the vertical depth of the recess. 8. The portable processing machine according to claim 7,
A portable processing machine in which the rounded portion is a single curved line extending across the entire length or width of the recess when viewed from above. The portable processing machine according to claim 7 or 8,
The recess has a bottom wall surrounded by the vertical walls, and a connecting region that connects the vertical walls and the bottom wall and has an arc shape in a side view . A method for manufacturing a base for a portable processing machine according to any one of claims 1 to 9, comprising the steps of:
A plate-shaped base body is formed using a molding die with magnesium as the raw material.
An edge portion having an arc shape in a side view is formed from the lower surface of the base molding body toward each of the front surface, rear surface, right side surface, and left side surface of the base molding body, the edge portion including the arc-shaped portion,
The lower surface of the base molding is planed to remove the edge portion while leaving the arc-shaped portion of the base;
A method for manufacturing a base for a portable processing machine, comprising providing the nickel plating layer on the entire surface of the base. A method for manufacturing a base for a portable processing machine according to claim 10, comprising the steps of:
A method for manufacturing a base for a portable processing machine, wherein the edge portion has an arc-shaped cross section throughout the thickness direction, and in the planing process, the lower portion of the arc-shaped cross section is removed and the upper portion remains as the arc-shaped portion. A method for manufacturing a base for a portable processing machine according to claim 10, comprising the steps of:
A method for manufacturing a base for a portable processing machine, wherein the edge portion has an arc-shaped cross section at the upper side and a straight line-shaped cross section below the arc-shaped cross section, and the entire straight line-shaped cross section is removed by the planing. A method for manufacturing a base for a portable processing machine according to claim 10, comprising the steps of:
The base molding has a bulge portion as part of the edge portion that bulges downward from the arc-shaped portion on the inner side of the arc-shaped portion, and the bulge portion is cut in the flat cutting process.

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