JP5849877B2 - Portable work machine - Google Patents

Description

  The present invention relates to a portable work machine used for cutting a work object with a rotary tool such as a disk cutter.

  There are a power cutter, a chain saw, etc. in the portable working machine provided with the rotary tool. The power cutter is used to perform cutting work such as creasing on a work object such as stone or concrete using a disk-shaped blade, that is, a disk cutter, as a rotary tool. The chain saw is used for cutting a work object such as wood using a saw chain which is a chain-shaped saw blade as a rotary tool. An engine or an electric motor is used as a drive source for driving the rotary tool. Such a portable work machine has a main body frame to which a handle to be gripped by an operator is attached. A drive unit provided with a drive source such as an engine is mounted on the main body frame, and a rotary tool is attached to the drive unit.

  For example, in a portable power cutter using an engine as a drive source, an arm is provided in a drive unit provided with the engine, and a disk cutter is rotatably attached to the arm. When cutting work is performed by gripping the handle provided on the main body frame, if vibration generated from the engine is transmitted to the handle, the burden on the operator increases, so in order to reduce engine vibration transmitted to the handle, A vibration isolation mechanism is generally provided between the main body frame and the engine.

  In Patent Document 1, an elastic member is provided between a main body frame provided with a handle and a casing constituting a drive unit provided with an engine so as to reduce vibration generated from the engine and transmitted to the handle. A chain saw is described.

JP 2011-189480 A

  As an anti-vibration mechanism used for a portable work machine, there are a spring-type anti-vibration mechanism using a spring member and a rubber-type anti-vibration mechanism using rubber. The spring type vibration isolation mechanism uses a coil spring as a spring member. Since the coil spring has a relatively large deformation amount, a high vibration isolation effect can be obtained. On the other hand, the deformation amount of the rubber vibration isolating mechanism is smaller than that of the spring vibration isolating mechanism. For this reason, in a portable working machine such as a power cutter or a chain saw in which cutting work is continuously performed for a long time, a spring type vibration isolation mechanism having a large vibration isolation effect is frequently used. However, since the spring-type vibration isolation mechanism has a large amount of deformation of the spring member, when the rotary tool is pressed against the work object, the rotary tool moves, and the rotary tool is moved to the exact cutting position of the work object. There is a problem that it is not easy to keep pressing and difficult to work.

  On the other hand, the rubber-type vibration isolating mechanism has a small amount of rubber deformation, so that when the rotary tool is pressed against the work object, the rotary tool does not move greatly, and the work object is at a specific cutting position. There is an advantage that it is easy to press the rotary tool and the cutting workability is relatively good. However, when the work continues for a long time, the vibration transmitted to the worker's hand is large, which places a burden on the worker.

  Depending on the type of work object, there is a usage pattern that prioritizes the vibration-proof effect and a usage pattern that prioritizes the pressing operability of the rotary tool, but conventional portable work machines are based on either usage pattern. It becomes the anti-vibration mechanism. For this reason, when a work object is cut using a portable work machine, there is a problem that workability is not good depending on the work object.

  An object of the present invention is to improve the workability of a portable work machine.

The portable work machine of the present invention is a portable work machine for cutting a work object with a rotary tool,
A main body frame provided with a handle to be gripped by an operator, a drive source to which the rotary tool is attached and driving the rotary tool, a drive unit mounted on the main body frame, the main body frame, and the drive unit An anti-vibration spring member mounted between the drive unit side and the main body frame side, and a rubber support mode position close to or in contact with the other of the drive unit side and the main body frame side. And an anti-vibration rubber member that can be switched and moved.

  The portable work machine according to the present invention is characterized in that the anti-vibration rubber member is sandwiched between the drive unit and the main body frame in a rubber support mode position. The portable work machine of the present invention includes a mode switching member that is movable between a spring support mode position and the rubber support mode position in the drive unit, and the mode switch member is set to the rubber support mode position when the mode switch member is set to the rubber support mode position. The anti-vibration rubber member is sandwiched between a mode switching member and the main body frame. In the portable work machine of the present invention, the mode switching member is formed by a rod-shaped member extending in the width direction of the main body frame, a rubber clamping member facing the outer peripheral surface of the mode switching member is provided on the main body frame, and the mode The anti-vibration rubber member is provided on at least one of the outer peripheral surface of the switching member and the rubber clamping member. The portable work machine according to the present invention is characterized in that a concave portion having a concave shape for sandwiching the anti-vibration rubber member between the rubber sandwiching member and the mode switching member is formed in the rubber sandwiching member.

  The portable work machine according to the present invention is characterized in that the mode switching member is provided with a stopper portion for restricting a relative movement amount of the drive unit with respect to the main body frame in the width direction. The portable work machine according to the present invention is characterized in that the anti-vibration rubber member is provided at a front end portion of the main body frame. In the portable work machine of the present invention, two or more vibration-proof spring members are provided between one side of the main body frame and the drive unit so as to be separated in the front-rear direction of the main body frame. One or more anti-vibration spring members are provided between the side and the drive unit.

  According to the present invention, the support mode is switched between the spring support mode in which the drive unit is supported by the vibration isolation spring member with respect to the main body frame and the rubber support mode in which the drive unit is supported by the vibration isolation rubber member with respect to the main body frame. be able to. When the support mode is set to the spring support mode, the operator can perform a cutting operation in a mode in which a high vibration isolation effect can be obtained. On the other hand, when the rubber support mode is set, when the rotary tool is pressed against the work object, the rotary tool does not move greatly, and it is easy to accurately press the rotary tool at a specific cutting position of the work object. Become. As a result, depending on the type of work object, it is possible to switch between a spring support mode where priority is given to the vibration isolation effect and a rubber support mode where priority is given to the pressing operability of the rotary tool. The used cutting work can be performed by selecting the optimum vibration-proofing support mode according to the work object.

It is a front view which shows the engine cutter as a portable working machine. It is a rear view of FIG. It is an enlarged front view of the A section in FIG. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is the side view of FIG. 3 seen from the arrow C direction in FIG. It is the DD sectional view taken on the line in FIG. It is the EE sectional view taken on the line in FIG. It is the FF sectional view taken on the line in FIG. It is sectional drawing which shows the part same as FIG. 8 when a drive unit is switched from the spring support mode to the rubber support mode.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, an engine cutter 10 as a portable work machine has a main body frame 11 as a work machine main body, and a rear handle 12 is provided at a rear end portion of the main body frame 11. It protrudes backward and is provided. The main body frame 11 is provided with a front handle 13 so as to cross over the front end portion thereof, and the base end portion of the front handle 13 is arranged on one side of the main body frame 11 as shown in FIG. The front handle 13 is fixed at the center in the front-rear direction, and the front end of the front handle 13 is fixed at the other end of the main body frame as shown in FIG. When an operator uses the engine cutter 10 to cut the work material that is the work object, the operator holds the rear handle 12 with one hand and lifts the engine cutter 10 by holding the front handle 13 with the other hand. become.

  A support stand 14 is attached to the front end portion of the main body frame 11, and leg portions 15 are provided so as to protrude downward at both left and right end portions of the support stand 14. A leg portion 16 is provided at the rear end portion of the rear handle 12 so as to protrude downward. When the engine cutter 10 is disposed on the base surface, the leg portions 15 and 16 abut on the base surface.

  A drive unit 20 is mounted on the main body frame 11. The drive unit 20 includes an engine 21 as a drive source. The engine 21 incorporates a crankcase 22 on which a crankshaft (not shown) is rotatably mounted, and a piston connected to the crankshaft via a connecting rod. The engine body 24 is configured by the crankcase 22 and the cylinder 23 attached thereto. The crankshaft of the engine 21 faces the width direction of the main body frame 11, that is, the lateral direction.

  As shown in FIG. 1, an arm 25 is attached to one side surface of the engine body 24, and a disk-shaped blade, that is, a disk cutter 26 is freely rotatable as a rotary tool at the tip of the arm 25. It is attached to. A drive pulley that is rotationally driven by the engine 21 via a clutch is provided at the base end portion of the arm 25, and a driven pulley that is attached to the rotating shaft of the disk cutter 26 is provided at the distal end portion. The belt is stretched over. A power transmission mechanism that transmits engine power to the disk cutter 26 is constituted by pulleys and belts. As shown in FIG. 2, a recoil starter cover 27 is provided on the other side surface of the main body frame 11, and a recoil starter (not shown) is incorporated in the cover. A blade cover 28 is attached to the front end of the arm 25 so as to cover the rear end side of the disk cutter 26.

  As shown in FIG. 1, a coil spring 31 is mounted as a vibration-proof spring member between the protruding end 22 a of the crankcase 22 constituting the drive unit 20 and the main body frame 11. A coil spring 32 as a vibration-proof spring member is mounted between the base end portion of the front handle 13 and the engine body 24. Similarly, as shown in FIG. 2, a coil spring 33 is mounted between the recoil starter cover 27 constituting the drive unit 20 and the main body frame 11 as an anti-vibration spring member.

  As shown in FIG. 4, the support stand 14 is attached to the front end portion of the main body frame 11 by a bolt 34, and the front end portion 13 a of the front handle 13 is circular pipe-shaped between the support stand 14 and the main body frame 11. It is formed into a shape that is crushed and sandwiched. A bolt 36 provided with a spring receiver 35 is attached to the inside of the protruding end 22a of the crankcase 22, and a nut 37 screwed to the bolt 36 is abutted against the outer surface of the protruding end 22a. Yes. One end of the coil spring 31 is attached to the spring receiver 35, and the other end of the coil spring 31 is abutted against the abutting surface of the main body frame 11, and the coil spring 31 faces the width direction of the engine cutter 10. Yes. In order to prevent the other end of the coil spring 31 from coming off the abutting surface of the main body frame 11 and to connect the coil spring 31 and the main body frame 11, a bolt 38 is attached to the bracket portion 11 a of the main body frame 11. Yes.

  The other two coil springs 32 and 33 are also mounted between the main body frame 11 and the drive unit 20 in the lateral direction of the engine cutter 10 using the same members as the coil spring 31. When the drive unit 20 is supported by the main body frame 11 via coil springs 31 to 33 as vibration-proof spring members, the drive unit 20 is suspended and supported by the main body frame 11 in a spring support mode. At this time, the drive unit 20 is in a floating state so as to be movable in the front-rear longitudinal direction of the main body frame 11, the lateral direction perpendicular to the main body frame 11, and the three-dimensional direction of the vertical direction.

  The amount of movement of the drive unit 20 in the spring support mode is set by the elastic deformation strokes of the three coil springs 31-33. In the spring support mode in which the movement amount of the drive unit 20 does not exceed a certain range, the drive unit 20 is supported in an anti-vibration manner by the coil springs 31 to 33.

  As shown in FIGS. 5 and 6, protective covers 39 a and 39 b are attached to the support stand 14 fixed to the main body frame 11. The protective cover 39 a partially covers the front surface of the support stand 14, and the protective cover 39 b covers the lower end of the main body frame 11.

  As shown in FIGS. 8 and 9, the bracket portion 11 a of the main body frame 11 is integrally provided with a cylindrical rubber accommodating cylinder 41 having a modified cross section as a rubber clamping member. A through hole 42 is formed. As shown in FIG. 7, a stepped rod-like member 43 is disposed as a mode switching member inside the rubber housing cylinder 41 as a rubber clamping member. The small-diameter base end portion 43a of the rod-like member 43 is inserted into a guide hole 45 formed in the protruding end portion 22a and the boss portion 44 provided on the protruding end portion 22a so as to be switched and moved along the guide hole 45. 3 and 8 show a state in which the bar-shaped member 43 is in the spring support mode position, and FIG. 9 shows a state in which the bar-shaped member 43 is in the rubber support mode position. When the rod-shaped member 43 is set to the position of the spring support mode, the drive unit 20 is supported by the coil springs 31 to 33 on the body frame 11 in an anti-vibration manner.

  The base end portion 43a of the rod-shaped member 43 is provided with a male screw, and a nut 46 is screwed to the base end portion 43a. By fastening the nut 46 to the base end portion 43a, the rod-like member 43 is fastened to either the spring support mode position or the rubber support mode position. As shown in FIG. 3, the nut 46 moves along a nut guide groove 47 formed on the outer surface of the boss portion 44 so as to be wider than the guide hole 45. An engagement groove 48 is formed on the end surface of the base end portion 43 b of the rod-shaped member 43, and a drive unit for the rod-shaped member 43 is rotated by engaging the engagement groove 48 with a tool (not shown) and rotating the rod-shaped member 43. As a result, the rod-shaped member 43 can be moved between the spring support mode position and the rubber support mode position.

  An anti-vibration rubber member 51 is provided on the outer peripheral surface of the rod-like member 43, and the through hole 42 of the rubber containing cylinder 41 is formed from the outer diameter of the anti-vibration rubber member 51 as shown in FIGS. 8 and 9. A large arcuate surface 42a having a large diameter, and a recess 42b made of a small-diameter arcuate surface substantially corresponding to the outer diameter of the vibration isolating rubber member 51. As shown in FIG. 9, when the anti-vibration rubber member 51 abuts against the recess 42b, the anti-vibration rubber member 51 is sandwiched between the drive unit 20 and the main body frame 11, and the drive unit 20 is in the rubber support mode. And is supported by the main body frame 11.

  As described above, when the rod-shaped member 43 is moved from the position of the spring support mode to the position of the rubber support mode, the drive unit 20 is protected from the spring support mode in which the vibration is supported by the coil springs 31 to 33 with respect to the main body frame 11. The vibration rubber member 51 is sandwiched between the drive unit 20 and the main body frame 11 and is switched to a rubber support mode in which the vibration isolation rubber member 51 supports the drive unit 20. In this rubber support mode, the rod-like member 43 contacts the rubber housing cylinder 41 via the vibration-insulating rubber member 51, and a cutting operation based on this contact position can be performed. In the cutting operation in the rubber support mode, since the movement of the disc cutter 26 is suppressed as compared with the spring support mode, the positioning workability when positioning the disc cutter 26 at a specific position of the work object can be improved.

  As the rubber support mode, FIG. 9 shows a state in which the anti-vibration rubber member 51 is set to a position where it is always in contact with the rubber housing cylinder 41 in an unloaded state. Sometimes it is sufficient to move the rod-like member 43 from the center of the rubber housing cylinder 41 so that the anti-vibration rubber member 51 starts to act before the anti-vibration spring is greatly deformed. It is possible to adjust arbitrarily according to.

  As shown in FIG. 7, a flange 43 b having a diameter larger than the inner diameter of the through hole 42 of the rubber housing cylinder 41 is provided as a stopper portion on the head of the rod-shaped member 43, and the flange 43 b is a boss portion 44. The opposing surface 44a constitutes a stopper portion. When the drive unit 20 moves relative to the body frame 11 relative to one side in the width direction of the engine cutter 10, the flange 43 b comes into contact with one end surface of the rubber housing cylinder 41 and the relative movement amount of the drive unit 20. To regulate. When the drive unit 20 moves relatively to the other side in the width direction of the engine cutter 10 with respect to the main body frame 11, the drive unit 20 abuts against the opposing surface 44a of the boss portion 44 serving as a stopper portion, thereby reducing the relative movement amount of the drive unit 20. regulate.

  At both ends of the anti-vibration rubber member 51, a flange portion 51a facing the flange 43b and a flange portion 51b facing the facing surface 44a of the boss portion 44 are provided. 43b is prevented from coming into direct contact with the end face of the rubber containing cylinder 41.

  As shown in FIG. 7, the anti-vibration rubber member 51 is provided on the outer peripheral surface of the rod-like member 43 on the drive unit 20 side, but the anti-vibration rubber member 51 is disposed inside the rubber housing cylinder 41 on the main body frame 11 side. You may make it provide in a surrounding surface. As described above, the anti-vibration rubber member 51 is provided on at least one of the drive unit 20 side and the main body frame 11 side.

  As shown in the drawing, the rubber clamping member may be a member having an arcuate cross section formed of only a portion having the recessed portion 42b, instead of the cylindrical rubber containing cylinder 41 having an irregular cross section. Further, if the vibration-proof rubber member 51 can be sandwiched between the drive unit 20 side and the main body frame 11 side when the rod-like member 43 is set to the rubber support mode position, the hollow portion 42b is not provided. The rubber clamping member may be formed of a member having a flat surface.

  In the illustrated engine cutter 10, a rod-like member 43 as a mode switching member is provided at the protruding end 22 a of the crankcase 22 on the drive unit 20 side, and a rubber housing cylinder 41 as a rubber clamping member is on the main body frame 11 side. It is provided in the bracket part 11a. On the other hand, when the rod-like member 43 is provided on the main body frame 11 side and the rubber housing cylinder 41 is provided on the drive unit 20 side, these are in a form in which these are reversed. Also in such a form, by switching the position of the rod-shaped member 43, the engine cutter 10 can be set to either the spring support mode or the rubber support mode according to the type of work object.

  In the engine cutter 10 described above, when the position of the mode switching member is set to the spring support mode position, the drive unit 20 is supported by the main body frame 11 by the coil springs 31 to 33 constituting the spring type vibration isolation mechanism. In the spring support mode, since the deformation amount of the coil springs 31 to 33 is relatively large, the operator can perform a cutting operation in a mode in which a high vibration isolation effect can be obtained. On the other hand, when the position of the mode switching member is switched to the position of the rubber support mode, the drive unit 20 is supported by the main body frame 11 by the vibration isolating rubber member 51 constituting the rubber vibration isolating mechanism. In this rubber support mode, the amount of deformation of the rubber is smaller than that of the spring, so that when the rotary tool is pressed against the work object, the rotary tool does not move greatly, and the specific cutting position of the work object It becomes easy to press the rotary tool accurately. In this way, depending on the type of work object, it is possible to switch between the spring support mode where priority is given to the vibration isolation effect and the rubber support mode where priority is given to the pressing operability of the rotary tool. When cutting the work object using the engine cutter 10 as a machine, optimum workability can be ensured according to the work object.

  Two coil springs 31 and 32 are provided between one side of the main body frame 11 and the drive unit 20, but if there are two or more, more than two coil springs should be provided. May be. Further, one coil spring 33 is provided between the other side of the main body frame 11 and the drive unit 20, but if there are one or more, more than one coil spring may be provided. good.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although the illustrated portable working machine is an engine cutter in which a disk cutter 26 as a rotary tool is driven by the engine 21, the disk cutter 26 may be driven by an electric motor. The present invention can also be applied to a chain saw.

DESCRIPTION OF SYMBOLS 10 ... Engine cutter (portable working machine), 11 ... Main body frame, 11a ... Bracket part, 12 ... Rear handle, 13 ... Front handle, 13a ... Tip part, 14 ... Support stand, 15 ... Leg part, 16 ... Leg part 20 ... drive unit, 21 ... engine, 22 ... crankcase, 22a ... projecting end, 23 ... cylinder, 24 ... engine body, 25 ... arm, 26 ... disc cutter, 27 ... cover, 28 ... blade cover, 31- 33 ... Coil spring (vibration-proof spring member), 34 ... Bolt, 35 ... Spring receiver, 36 ... Bolt, 37 ... Nut, 38 ... Bolt, 41 ... Rubber housing cylinder (rubber clamping member), 42 ... Through hole, 42a ... large-diameter arc surface, 42b ... hollow part, 43 ... rod-shaped member (mode switching member), 43a ... base end part, 43b ... flange (stopper part), 44 ... boss part, 44 ... facing surface (stopper portion), 45 ... guide hole, 46 ... nut, 47 ... nut guide groove 48 ... engaging groove, 51 ... vibration damping rubber member, 51a ... flange portion, 51b ... flange portion.

Claims (8)

A portable work machine that cuts a work object with a rotary tool,
A body frame provided with a handle to be gripped by an operator;
A drive unit to which the rotary tool is attached and a drive source for driving the rotary tool;
An anti-vibration spring member mounted between the main body frame and the drive unit;
An anti-vibration rubber member that is provided on at least one of the drive unit side and the main body frame side and can be switched to a rubber support mode position that approaches or contacts the other of the drive unit side and the main body frame side; A portable work machine that is characterized.   2. The portable work machine according to claim 1, wherein the anti-vibration rubber member is sandwiched between the drive unit and the main body frame at a rubber support mode position.   A mode switching member movable between a spring support mode position and the rubber support mode position is provided in the drive unit, and when the mode switch member is set to the rubber support mode position, the mode switching member and the main body frame The portable work machine according to claim 2, wherein the anti-vibration rubber member is sandwiched between them.   The mode switching member is formed by a rod-like member extending in the width direction of the main body frame, a rubber clamping member facing the outer peripheral surface of the mode switching member is provided in the main body frame, and the outer peripheral surface of the mode switching member and the rubber clamping The portable work machine according to any one of claims 1 to 3, wherein the anti-vibration rubber member is provided on at least one of the members.   4. The portable work machine according to claim 3, wherein a concave portion having a concave shape for holding the vibration isolating rubber member between the rubber holding member and the mode switching member is formed in the rubber holding member.   The portable work machine according to claim 3, wherein a stopper portion for restricting a relative movement amount of the drive unit with respect to the main body frame in the width direction is provided on the mode switching member.   The portable work machine according to claim 1, wherein the vibration-proof rubber member is provided at a front end portion of the main body frame.   Two or more anti-vibration spring members are provided between one side of the main body frame and the drive unit in the front-rear direction of the main body frame, and between the other side of the main body frame and the drive unit. The portable work machine according to claim 1, wherein one or more vibration-proof spring members are provided.

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