Portable power tool

Abstract

To provide a portable power tool that enables stable machining in the vicinity of the end portion of a workpiece.SOLUTION: A portable power tool includes: a main body 100 having a motor 110, a rotary tool 120 that is rotated by the motor 110, and a housing 130 that projects the rotary tool 120 from the bottom surface side, where the main body 100 is moved forward while being pushed downward during use; and a guide rail 10 that supports the main body 100 and guides the forward movement of the main body 100. The guide rail 10 includes: a laying section R that is laid on a workpiece W; and an extension section E that is extended in a cantilevered manner from the laying section R.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a portable power tool, and particularly to a portable power tool for grinding or cutting a welding bead.

Background Art

[0002] Patent Document 1 describes a welding bead surface grinding apparatus that has a traveling carriage with four wheels, an electric motor mounted on the traveling carriage, and a grinding wheel fixed to the electric motor, and cuts the bead surface while moving the traveling carriage on a large aluminum plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The welding bead surface grinding apparatus of Patent Document 1 is premised on cutting with all four wheels placed on a large aluminum plate. Therefore, stable cutting cannot be performed in the vicinity of an end where some wheels protrude outside the large aluminum plate.

[0005] Therefore, an object of the present invention is to provide a portable power tool capable of stably performing processing in the vicinity of an end of a workpiece.

Means for Solving the Problems

[0006] The portable power tool of the present invention includes a motor 110, a rotating tool 120 rotated by the motor 110, and a housing 130 that projects the rotating tool 120 from the bottom surface side, and has a main body 100 that is used by moving forward while pressing downward, and a guide rail 10 that supports the main body 100 and guides the forward movement of the main body 100. The guide rail 10 is characterized by having a laying portion R laid on the workpiece W and an extended portion E extending in a cantilevered manner from the laying portion R.

[0007] In this portable power tool, it is preferable that the guide rail 10 has two rail members 20, and the rotating tool 120 is located between the two rail members 20 in a plan view.

[0008] Further, it is preferable that the guide rail 10 is provided with clamping means 40 for attaching to the workpiece W or a magnet 40A for attaching to the workpiece W.

[0009] Also, the main body 100 includes a front leg 131 and a rear leg 132 attached to the guide rail 10. The guide rail 10 includes a contact surface 421a that contacts the rear end surface W2 of the workpiece W, and a stopper 60 that restricts the main body 100 from coming out from the rear end of the guide rail 10. In a state where the stopper 60 restricts the rearward movement of the main body 100, at least a part of the contact point (first attachment portion 131a) of the front leg 131 with the guide rail 10 is preferably located in front of the contact surface 421a.

Advantages of the Invention

[0010] The portable power tool of the present invention can support the main body in a state where it is pushed out from the workpiece by the extended portion, and can stably perform processing near the end of the workpiece.

[0011] In the above portable power tool, when the guide rail has two rail members and the rotating tool is located between the two rail members in a plan view, the force pressing the main body downward is applied to the two rail members substantially evenly, and the twist of the guide rail when the main body is located at the extended portion can be suppressed.

[0012] When the guide rail is provided with clamping means for attaching to the workpiece or a magnet for attaching to the workpiece, the attachment of the guide rail to the workpiece is stabilized.

[0013] The main body includes a front leg and a rear leg attached to the guide rail, the guide rail includes a contact surface that abuts against the rear end surface of the workpiece, and a stopper that restricts the main body from slipping out from the rear end of the guide rail. When at least a part of the contact point of the front leg with the guide rail is located in front of the contact surface in a state where the movement of the main body backward is restricted by the stopper, by mainly applying the downward pressing force applied to the main body during use to the front leg, when the main body is located at the extended portion, the rotation of the guide rail can be suppressed such that the rear of the extended portion drops and the front of the laying portion rises.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0015] Next, an embodiment of the portable power tool 1 of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the portable power tool 1 of the present invention includes a motor 110, a rotating tool 120 rotated by the motor 110, and a housing 130 that projects the rotating tool 120 from the bottom surface side, and a main body 100 that is used by moving forward while pressing downward, and a guide rail 10 that supports the main body 100 and guides the forward movement of the main body 100. Hereinafter, the components of the main body 100 will be described first.

[0016] The motor 110 is an air motor using compressed air as a drive source. However, it may be an electric motor using electricity as a drive source, not limited to an air motor. The rotational force generated by the motor 110 is transmitted to the rotating tool 120 via, for example, gears (not shown).

[0017] The rotating tool 120 is for machining a workpiece W by cutting, grinding, polishing, etc., and is, for example, a cutter having a blade provided on the outer periphery of a thick disk. This cutter has tungsten carbide as a main component. The rotation axis S120 of the rotating tool 120 is substantially orthogonal to the traveling direction of the main body 100, that is, the extending direction of the guide rail 10 in plan view. The rotation direction of the rotating tool 120 is, for example, a direction in which chips are thrown forward. However, it may be rotated in a direction in which chips are thrown backward.

[0018] The housing 130 is a substantially hollow rectangular parallelepiped, and houses the motor 110 at the rear and the rotating tool 120 at the front. A part of the rotating tool 120 projects downward from the opening on the bottom surface. A front leg 131, a rear leg 132, a front handle 133, and a rear handle 134 are attached to the housing 130. The rotating tool 120 is located inside the front leg 131 and the rear leg 132 in plan view.

[0019] The front legs 131 are provided one each on the left and right sides of the rotating tool 120. Each front leg 131 includes a first mounting portion 131a slidably attached to the guide rail 10, and a first leg portion 131c extending upward and rearward from the first mounting portion 131a. The first mounting portion 131a serves as the contact point between the front leg 131 and the guide rail 10. The center of the first mounting portion 131a in the front-rear direction is located in front of the rotation axis S120 of the rotating tool 120. Preferably, the entire first mounting portion 131a is located in front of the rotation axis S120 of the rotating tool 120. As shown in FIG. 3, the lower part of the first mounting portion 131a has a substantially inverted U-shaped cross-sectional shape, and protrusions 131b are provided on both inner side surfaces. By fitting these protrusions 131b into the concave grooves 20a provided on both side surfaces of the rail member 20 of the guide rail 10 described later, movement in the front-rear direction along the rail member 20 is enabled, while preventing detachment in the vertical and lateral directions.

[0020] The front leg 131 configured as described above can have its protruding length from the housing 130 adjusted by the length adjustment mechanism 150. The length adjustment mechanism 150 includes an internal thread 151 and an external thread 152 screwed into the internal thread 151. One of the internal thread 151 or the external thread 152 (the internal thread 151 in FIG. 3) is rotatably fixed to the housing 130, and the other thread (the external thread 152 in FIG. 3) is connected to the first leg portion 131c of the front leg 131. By turning one of the threads, the protruding length of the other thread from the one thread can be changed, that is, the protruding length of the front leg 131 from the housing 130 can be changed. When the protruding length of the front leg 131 becomes shorter, the position of the rotating tool 120 drops, and when the protruding length of the front leg 131 becomes longer, the position of the rotating tool 120 rises. One of the threads can be rotated by turning a dial 153 protruding from the upper part of the housing 130.

[0021] Two rear legs 132 are provided behind the housing 130. The rear legs 132 include a second mounting portion 132a slidably attached to the guide rail 10 and a second leg portion 132b extending upward from the second mounting portion 132a. The second mounting portion 132a serves as the contact point between the rear leg 132 and the guide rail 10. The cross-sectional shape of the second mounting portion 132a is the same as that of the first mounting portion 131a of the front leg 131. The upper part of the second leg portion 132b is pivotally supported by an extension portion 160 extending from the rear part of the housing 130 as shown in FIG. 1.

[0022] The rotation axis S160 by pivotal support is substantially orthogonal to the traveling direction of the main body 100 in plan view. When the protruding length of the front leg 131 is changed by the length adjustment mechanism 150, the main body 100 rotates about this rotation axis S160, and as a result, the rotating tool 120 moves up and down.

[0023] An engaging tool 135 for restricting unintentional movement of the main body 100 on the guide rail 10 is attached to the rear leg 132. By inserting the lower end of this engaging tool 135 into the insertion hole 60a of the stopper 60 attached to the rear end of the guide rail 10, the movement of the main body 100 on the guide rail 10 is restricted.

[0024] The front handle 133 is located in front of the housing 130. The grip portion 133a of the front handle 133 is located in front of the rotating tool 120 and the first mounting portion 131a of the front leg 131 in plan view.

[0025] The rear handle 134 is located at the rear and upper part of the housing 130. The rear handle 134 is annular and is attached with the opening facing in the left - right direction. The grip portion 134a is located at the upper rear part of the ring and is located behind the center in the front - rear direction of the second mounting portion 132a of the rear leg 132 in plan view.

[0026] Next, the guide rail 10 will be described. The guide rail 10 has a laying portion R laid on the workpiece W and an extending portion E extending in a cantilever manner from the laying portion R. This guide rail 10 includes two rail members 20, a connecting member 30 connecting the rail members 20 to each other, a fixing means for fixing the guide rail 10 to the workpiece W, a restricting tool 50 for restricting the withdrawal of the main body 100 from the front end of the guide rail 10, and a stopper 60 for restricting the withdrawal of the main body 100 from the rear end of the guide rail 10.

[0027] As shown in FIG. 2, the two rail members 20 are fixed to each other by the connecting member 30 while being arranged substantially parallel to each other. When the main body 100 is attached to the rail member 20, the rotating tool 120 is positioned between the two rail members 20 in a plan view. Also, the grip portion 133a of the front handle 133 is substantially orthogonal to the extending direction of the guide rail 10 in a plan view, but the center in the left - right direction of the grip portion 133a is positioned between the two rail members 20 in a plan view. Further, the grip portion 134a of the rear handle 134 is substantially parallel to the extending direction of the guide rail 10 in a plan view, and when the main body 100 is advanced, it will be positioned between the two rail members 20.

[0028] The restricting tool 50 is provided near the front ends of both rail members 20. This restricting tool 50 protrudes above the upper surface of the rail member 20 and, when the main body 100 moves forward, abuts against the front end of the first attachment portion 131a of the front leg 131 to restrict further forward movement.

[0029] The stopper 60 is provided at the rear end of one of the rail members 20. This stopper 60 protrudes upward from the upper surface of the rail member 20. When the main body 100 moves backward, it abuts against the rear end of the second attachment portion 132a of the rear leg 132 to restrict further backward movement. Since the main body 100 cannot be attached to or detached from the rail member 20 unless either the restricting tool 50 or the stopper 60 is removed, it is preferable that at least one of them can be easily attached and detached. In FIG. 1, a screw is integrally provided at the lower end of the restricting tool 50 so that it can be attached and detached by simply turning the screw. Also, the stopper 60 is fixed to the rail member 20 via a screw and can be attached and detached by simply turning the screw.

[0030] The fixing means is the clamping means 40 for clamping the workpiece W. The clamping means 40 clamps the workpiece W from the front-rear direction and includes a front member 41 and a rear member 42.

[0031] The front member 41 includes a first contact portion 411 that contacts the front end face W1 of the workpiece W, and pressing means 412 for pressing the first contact portion 411 against the front end face W1. The workpiece W in FIG. 1 is a square steel pipe, and welding beads W3 are continuous in the circumferential direction. Therefore, in order to avoid contact with the welding beads W3, an avoidance groove 411b is provided on the pressing surface 411a of the first contact portion 411 that is pressed against the workpiece W (see FIG. 2). The pressing means 412 includes a base portion 412a fixed to the rail member 20 or the connecting member 30, a lever 412b attached to the base portion 412a, and a shaft portion 412c pushed out from the base portion 412a by the lever 412b. The first contact portion 411 is connected to the tip of the shaft portion 412c.

[0032] The rear member 42 is substantially L-shaped in side view, and includes a second contact portion 421 that contacts the rear end surface W2 of the workpiece W, and a fixing portion 422 that extends rearward from the upper end of the second contact portion 421 and is fixed to the rail member 20 or the connecting member 30. Further, a reinforcing member 423 straddling the second contact portion 421 and the fixing portion 422 is provided. The front surface of the second contact portion 421 becomes a contact surface 421a that contacts the rear end surface W2 of the workpiece W. And the portion located in front of this contact surface 421a and on the workpiece W becomes the laying portion R. Also, the portion behind the contact surface 421a becomes the extending portion E and protrudes from the workpiece W. Note that since the portion in front of the pressing surface 411a of the first contact portion 411 also protrudes from the workpiece W, this portion can also be referred to as the extending portion E.

[0033] Further, the distance L1 from the contact surface 421a to the front end of the stopper 60 (the surface where the rear end of the second attachment portion 132a contacts) is shorter than the distance L2 from the front end of the first attachment portion 131a to the rear end of the second attachment portion 132a. Therefore, in a state where the main body 100 is attached to the guide rail 10 and the movement of the main body 100 backward is restricted by the stopper 60, at least a part of the first attachment portion 131a, which is the contact point of the front leg 131 with the guide rail 10, is located in front of the contact surface 421a. In other words, at least a part of the first attachment portion 131a is located in the laying portion R. Note that it is preferable that the entire first attachment portion 131a is located in front of the contact surface 421a.

[0034] Also, the distance L2 is longer than the distance L3 from the lowest point (the point in contact with the welding bead W3) P120 of the rotator 120 to the rear end of the second attachment portion 132a. Therefore, in a state where the main body 100 is attached to the guide rail 10 and the movement of the main body 100 backward is restricted by the stopper 60, the lowest point P120 of the rotator 120 is located behind the rear end of the workpiece W.

[0035] Next, a method of using the portable power tool 1 with the above configuration will be described. First, attach the portable power tool 1 to the workpiece W. When attaching, while positioning the workpiece W between the first abutting portion 411 and the second abutting portion 421, with the abutting surface 421a of the second abutting portion 421 in contact with the rear end surface W2 of the workpiece W, tilt the lever 412b of the pressing means 412 downward, and press the first abutting portion 411 against the workpiece W with the shaft portion 412c pushed out by the lever 412b. Thereby, the workpiece W is clamped between the first abutting portion 411 and the second abutting portion 421, and the attachment is completed.

[0036] After the attachment is completed, rotate the dial 153 as necessary to adjust the height of the rotating tool 120. Then, with the rotating tool 120 rotated by the motor 110, move the main body 100 forward along the guide rail 10 to cut the welding bead W3. At this time, since the extension portion E allows the main body 100 to be positioned behind the workpiece W rather than on it, the rotating tool 120 can be positioned behind the rear end of the workpiece W. As a result, the welding bead W3 can be cut from the rear end of the workpiece W. Also, since the extension portion E is provided at the front as well, the rotating tool 120 can be positioned in front of the front end of the workpiece W. As a result, the welding bead W3 can be cut up to the front end of the workpiece W. That is, the welding bead W3 can be continuously cut at once from the rear end to the front end of the workpiece W.

[0037] Also, when cutting, the main body 100 is pressed downward, but since at least a part of the first attachment portion 131a is located in the laying portion R, the pressing force can be transmitted to the workpiece W through the laying portion R, and the rotation of the guide rail 10, which may occur by pushing down the extension portion E and causing the rear of the extension portion E to drop and the front of the laying portion R to rise, can be suppressed.

[0038] In addition, since the extension part E is cantilevered and thus prone to torsion, but the rotating tool 120 is positioned between the two rail members 20 in a plan view, the force pressing the main body 100 downward is applied to the two rail members 20 substantially evenly, so that the torsion of the guide rail 10 when the main body 100 is positioned at the extension part E can be suppressed.

[0039] In addition, to remove the portable power tool 1 from the workpiece W, the lever 412b may be lifted upward to move the first contact part 411 forward to release the clamping state.

[0040] Next, another portable power tool 1 will be described with reference to FIG. 4. This portable power tool 1 uses a magnet 40A as a fixing means. The magnet 40A is a permanent magnet, but it may also be an electromagnet. The installation location of the magnet 40A is preferably provided, for example, in front of and behind the rail member 20. However, it may be provided on either the front or the rear side. When the magnet 40A is provided later, the front end face of the magnet 40A may be used as a contact surface 421a that contacts the rear end face W2 of the workpiece W. Also, the magnet 40A may be provided over the entire length of the rail member 20.

[0041] Even when the magnet 40A is used as the fixing means, the guide rail 10 can be stably attached to the workpiece W, so that the same operational effects as those of the portable power tool 1 in FIG. 1 can be achieved.

[0042] As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the above embodiments, and various modifications can be made and implemented within the scope of the present invention. For example, in the above embodiments, the first attachment part 131a and the second attachment part 132a slid on the rail member 20, but they may be made to travel along the rail member 20 instead of wheels. Also, various known ones can be adopted as long as they are movable along the rail member 20.

[0043] In addition, as the length adjustment mechanism 150, not limited to adjustment by a screw, various known length adjustment mechanisms can be adopted. Further, since the length adjustment mechanism 150 is for adjusting the vertical position of the rotating tool 120, instead of changing the protruding length of the front leg 131, it may be configured to directly change the protruding length of the rotating tool 120 from the housing 130. For example, if the rotating tool 120 and the other screw are connected, the vertical position of the rotating tool 120 can be directly changed.

[0044] In addition, as the pressing means 412, the shaft portion 412c may be extended and retracted by a screw, and various known pressing means can be adopted. Further, the rotating tool 120 is not limited to a cutter, and may be a grindstone, a cutting tool, a file, a brush, or various abrasives. The workpiece W is not limited to a square steel pipe, and may be a shaped steel such as an H-shaped steel or a steel plate. Further, it is not limited to steel, and may be various metals such as aluminum and stainless steel.

Explanation of Signs

[0045] 1 Portable power tool 100 Main body 110 Motor 120 Rotating tool S120 Rotating shaft P120 Lowest point 130 Housing 131 Front leg 131a First mounting portion 131b Protrusion 131c First leg portion 132 Rear leg 132a Second mounting portion 132b Second leg portion 133 Front handle 133a Grip portion 134 Rear handle 134a Grip portion 135 Engaging tool 150 Length adjustment mechanism 151 Female screw 152 Male screw 153 Dial 160 Extension portion S160 Rotating shaft by shaft support 10 Guide rail R Laying part E Extension part 20 Rail material 20a Concave groove 30 Connecting material 40 Clamping means 40A Magnet 41 Front member 411 First contact part 411a Pressing surface 411b Avoidance groove 412 Pressing means 412a Base part 412b Lever 412c Shaft part 42 Rear member 421 Second contact part 421a Contact surface 422 Fixing part 423 Reinforcing material 50 Regulator 60 Stopper 60a Insertion hole W Workpiece W1 Front end face of workpiece W2 Rear end face of workpiece W3 Weld bead L1 Distance from contact surface to front end of stopper L2 Distance from front end of first mounting part to rear end of second mounting part L3 Distance from lowest point of rotating tool to rear end of second mounting part

Claims

1. It has a motor, a rotating tool rotated by the motor, and a housing that projects the rotating tool from the bottom surface side, and a main body that is used by moving forward while pressing downward. It is provided with a guide rail that supports the main body and guides the forward movement of the main body. A portable power tool in which the guide rail has a laying portion laid on a workpiece and an extending portion extending in a cantilever manner from the laying portion.

2. The guide rail has two rail members. The portable power tool according to Claim 1, wherein the rotating tool is located between the two rail members in a plan view.

3. The portable power tool according to Claim 1 or 2, wherein the guide rail is provided with clamping means for attaching to a workpiece.

4. The portable power tool according to Claim 1 or 2, wherein the guide rail is provided with a magnet for attaching to a workpiece.

5. The main body is provided with a front leg and a rear leg that are attached to the guide rail. The guide rail is provided with a contact surface that abuts against the rear end surface of the workpiece and a stopper that restricts the main body from coming out from the rear end of the guide rail. The portable power tool according to Claim 1 or 2, wherein at least a part of the contact point of the front leg with the guide rail is located in front of the contact surface in a state where the backward movement of the main body is restricted by the stopper.

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