JP2006314278A - Brush cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brush cutter not only capable of being driven by each of an engine and an electrically driven motor according to the use environment as a power source, but also enabling a locked state to be released when a cutter is locked by cut leaves or the like when driven by the electrically driven motor. <P>SOLUTION: A cutter 13 is joined to the tip of an operation arm 10 and a follow-side joint 17 is installed in the rear side of the operation arm 10. Each of an engine output-side joint 30 of the engine 18, and a motor output-side joint 31 of the electrically driven motor 19 is selectively and detachably attached to the follow-side joint 17. A handle 16 is installed in the center part of the operation arm 10 in the longitudinal direction, and a lock-releasing switch 45 for reversely rotating the cutter 13 for a prescribed number of rotation or a prescribed time by reversely rotating the electrically driven motor when the cutter 13 is locked by the coiling of the leaves or the like around the cutter 13 is installed in the handle 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brush cutter capable of driving a cutter using either an engine or an electric motor as a power source.

  Brush cutters, also called mowers, are used to cut weeds that grow on the banks of Tabata and the banks of Kawahara, undergrowth and pasture of mountain forests. There are two types of brush cutters: an arm connection type in which a cutter is attached to the tip of the operating arm and a power source is attached to the rear end, and a direct-acting type in which a cutter is directly attached to the rotary shaft of the power source. As a source, there are a case where an engine is mounted and a case where an electric motor is mounted.

  A brush cutter using an electric motor as a power source is, for example, a linear motion type in which an electric motor is attached to the tip of an operation arm and a cutter is directly attached to the shaft of the electric motor, as described in Patent Document 1. Many. As described in Patent Document 2, for example, there are many arm connection types in which a cutter is attached to the front end of the operation arm and the engine is attached to the rear end.

  The arm connection type with the cutter attached to the front end of the operation arm and the engine attached to the rear end has a shoulder-type loop belt attached to the operation arm. There are a shoulder type that can be hung on a handle, a handle type that is operated by holding a handle provided on an operation arm, and the handle has a loop handle and a two-hand handle.

The cutter attached to these brush cutters has a disk-shaped metal blade provided with a plurality of cutting blades. The metal blades have four blades, eight blades, and more than 30 blades depending on the number of blades. Some blades are provided in a saw blade shape. As the metal blade, a single blade type in which a cutting edge is provided only on a side surface on one side in the rotation direction of the cutting blade is often used. When such a single-edged cutter is attached to a brush cutter to perform the cutting operation, the cutting edge of the cutting blade on the traveling direction side is made to be a weed by moving the rotating cutter almost parallel to the ground. This will be reaped by contact.
Japanese Utility Model Publication No.5-2620 JP 2004-8054 A

  A normal brush cutter has a cover that covers the operator side of the cutter in order to ensure the safety of the operator, and mowing leaves such as weeds that have been cut are entangled between the cutter and the cover. The rotation may be stopped by locking, and weeds that have not been cut may be entangled with the rotation axis of the cover or the cutter, or foreign matter such as trees may be caught in the cutting blade and the cutter may be locked.

  When the cutter is locked by cutting leaves in this way, conventionally, it is necessary to remove the cutting leaves entangled with the cutter by manually reversing the cutter after stopping the operation of the power source, It is difficult to perform the mowing leaf removal work safely and easily.

  The object of the present invention is that the brush cutter can be driven by using either the engine or the electric motor as a power source according to the usage environment, and is easy when the cutter is locked by the cutting leaves or the like while being driven by the electric motor. It is to be able to release the lock.

  The brush cutter according to the present invention includes a brush cutter main body to which a cutter is connected at the tip and a driven shaft having a driven side connecting portion at the other end is rotatably mounted, and the cutter is attached to the brush cutter main body to be detachable. An electric motor that drives in opposite directions, an engine output side joint that is provided on the output shaft of the engine and that is connected to the driven side connection portion, and an output shaft of the electric motor. The brush cutter body is provided with a driven side joint that is selectively detachably attached to any of the motor side joints that incorporate the drive side coupling portion coupled to the driven side coupling portion. A lock release switch that reverses the cutter when the cutter driven by the electric motor is locked with the electric motor attached to the brush cutter. Characterized by detachably attached to the body.

  The brush cutter according to the present invention is characterized in that the brush cutter main body is formed by a hollow bar-shaped operation arm into which a handle gripped by an operator is provided at a central portion in the longitudinal direction and the driven shaft is inserted.

  The brush cutter according to the present invention is characterized in that the lock release switch is provided in a holder that is connected to the electric motor via a cable and is detachably attached to the handle.

  According to the present invention, either the engine or the electric motor can be selectively attached to the brush cutter main body, and the engine and the electric motor are prepared as attachments, so that it can be used according to the usage environment in the mowing work. The brush cutter can be used as an engine driven type or a motor driven type. When the cutter is driven by an electric motor and the leaf is entangled with the cutter and the rotation of the cutter is stopped, the cutter can be reversed by operating the lock release switch. Leaves can be easily removed.

  According to the present invention, the brush cutter main body is formed by the operation arm provided with the handle, so that the operator can perform the cutting operation by grasping the handle and operating the operation arm. The lock release switch connected to the electric motor can be detachably attached to the handle by the holder, and by providing the lock release switch on the handle, the lock release switch can be operated while the handle is gripped. good.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a brush cutter according to an embodiment of the present invention. FIG. 1 (A) shows a state in which an engine is mounted on a brush cutter body, and FIG. The state where the motor is mounted is shown. The brush cutter shown in FIG. 1 is of an arm connection type and has an operation arm 10 as a brush cutter body. The operation arm 10 is composed of a hollow rod-like member, and a driven shaft 11 is rotatably mounted inside (see FIGS. 2 and 4).

  A support member 12 is attached to the distal end portion of the operation arm 10, and a metal cutter 13 is rotatably attached to the support member 12, and the cutter 13 is attached to the distal end of the driven shaft 11 with a pair of bevel gears (not shown). ). The cutter 13 is a disk-shaped metal blade in which a plurality of cutting blades 14 are provided in a saw blade shape, and is a single-blade type in which a cutting edge is provided only on one side surface in the rotation direction of the cutting blade. A cover 15 is attached to the tip of the operation arm 10 so as to cover the operator side of the cutter 13. This cover 15 prevents the operator from coming into contact with the cutter 13, thereby ensuring work safety. .

  Two handles 16 are attached to the center of the operation arm 10 in the longitudinal direction, and the operator can lift and move the cutter 13 from the ground by holding the handle 16 with both hands. In the illustrated case, the brush cutter is a two-handed handle type in which two handles 16 are attached to the operation arm 10, but instead of this, a loop handle type may be used. It is also possible to attach a belt and make the brush cutter shoulder type.

  A driven side joint 17 is attached to the rear end portion of the operating arm 10 as a joint on the main body side of the brush cutter, and the operating arm 10 is a portion of the driven side joint 17, as shown in FIG. As shown in FIG. 1B, both the electric motor 19 and the electric motor 19 are selectively detachably mounted.

  2 is an enlarged cross-sectional view showing a part of the brush cutter shown in FIG. 1 (A), FIG. 3 (A) is a front view of the engine, and FIG. 3 (B) is shown in FIG. It is a side view of an engine. The engine 18 is a four-cycle single-cylinder gasoline engine. A crankcase that rotatably supports an engine output shaft 21 including a crankshaft is incorporated in the engine cover 20, and a piston can reciprocate in the crankcase. An engine constituent member (not shown) such as a cylinder to be mounted on is installed. The engine output shaft 21 is provided with a recoil starter, and the engine 18 can be started by pulling the recoil knob 22. When the engine 18 is driven using gasoline in the fuel tank 23 as fuel, the cooling fan 24 attached to the engine output shaft 21 cools the engine 18.

  4 is an enlarged sectional view showing a part of the brush cutter shown in FIG. 1 (B), FIG. 5 (A) is a front view of the electric motor, and FIG. 5 (B) is shown in FIG. It is a side view of the electric motor shown. The electric motor 19 has a substantially hexagonal columnar motor case 25, and a motor output shaft 26 made of an amateur shaft is rotatably supported by the motor case 25. A motor component (not shown) such as a fixed armature or a magnet facing the armature is incorporated. A rechargeable battery 27 such as a lithium ion battery is mounted on the outer periphery of the electric motor 19, and the electric motor 19 can be driven by electric power supplied from the battery 27.

  6A is a front view of the driven side joint, and FIG. 6B is a side view of the driven side joint shown in FIG. The driven joint 17 is formed in a cup shape having a larger diameter than the operation arm 10 and is attached to the rear end portion of the operation arm 10, and a square flange portion 28 is provided at the open end thereof. Fastening holes 28 a into which bolts 29 as fastening members are screwed are formed at the four corners of the flange portion 28.

  As shown in FIG. 3 (A), the engine cover 20 is provided with an engine output side joint 30 in which fastening holes 30a corresponding to the fastening holes 28a are formed. The engine 18 can be detachably mounted on the driven side joint 17 by screwing the bolts 29 into the fastening holes 28a, 30a in a state where the engine output side joint 30 is abutted. As shown in FIG. 5A, the motor case 25 is provided with a motor output side joint 31 having a fastening hole 31a corresponding to each of the fastening holes 28a, and is provided on the flange portion 28 of the driven side joint 17. The electric motor 19 can be detachably attached to the driven side joint 17 by screwing the bolts 29 into the fastening holes 28a, 31a in a state where the motor output side joint 31 is abutted. In addition, the code | symbol 32 shown in FIG. 2, FIG. 3 is a rubber-made sealing member.

  As shown in FIGS. 2 and 4, a clutch drum 33 that is fixed to the driven shaft 11 and rotates integrally with the driven shaft 11 is incorporated in the driven side joint 17. A driven side connecting portion is configured.

  As shown in FIG. 2, a pair of clutch shoes 35 provided at the tip of the engine output shaft 21 are incorporated in the engine output side joint 30, and a drive side connecting portion is configured by the clutch shoes 35. ing. As shown in FIG. 1A, when the engine 18 is mounted on the driven joint 17, the centrifugal clutch 36 is connected between the driven shaft 11 and the engine output shaft 21 by the clutch shoe 35 and the clutch drum 33. Composed.

  FIG. 7 is a cross-sectional view in FIG. As shown in FIG. 2, a disk-shaped rotating plate 37 is fixed to the engine output shaft 21, and as shown in FIG. 7, a clutch shoe 35 is swingably mounted on the rotating plate 37 by a pin 38. ing. A tension coil spring 39 is attached to each clutch shoe 35, and the tension coil spring 39 applies a spring force in a direction in which the friction contact portion 35 a is separated from the inner peripheral surface of the clutch drum 33 to each clutch shoe 35. It has been.

  Thus, when the engine 18 is started by pulling the recoil knob 22, the centrifugal clutch 36 is in an open state, and no great resistance is applied to the recoil knob 22, so that the engine 18 can be started easily. Furthermore, due to the centrifugal force that increases as the engine speed increases, the clutch shoe 35 expands against the spring force of the tension coil spring 39 and is pressed against the inner peripheral surface of the clutch drum 33 to be connected to the clutch drum 33. The engine output shaft 21 is directly connected to the driven shaft 11 via the centrifugal clutch 36, whereby the cutter 13 can be rotated via the driven shaft 11 to cut grass.

  A pair of clutch shoes 40 as drive side connecting portions are provided at the tip of the motor output shaft 26, and these clutch shoes 40 are incorporated in the motor output side joint 31, as shown in FIG. When the driven side joint 17 is fastened to the motor output side joint 31, the clutch shoe 40 and the clutch drum 33 constitute a centrifugal clutch 41 between the driven shaft 11 and the motor output shaft 26.

  As shown in FIG. 4, a disc-shaped rotating plate 42 is fixed to the motor output shaft 26, and a clutch shoe 40 is swingably mounted on the rotating plate 42 using a pin (not shown). Each clutch shoe 40 is provided with a tension coil spring 43, and the tension coil spring 43 applies a spring force in a direction in which the friction contact portion 40 a is separated from the inner peripheral surface of the clutch drum 33 to each clutch shoe 40. It has been.

  As a result, the clutch shoe 40 expands against the spring force of the tension coil spring 43 due to the centrifugal force that increases as the number of revolutions of the electric motor 19 increases, and is pressed against the inner peripheral surface of the clutch drum 33 to cause the clutch drum The motor output shaft 26 is connected to the driven shaft 11 via the centrifugal clutch 41 and can rotate the cutter 13 via the driven shaft 11 to cut grass. Further, when the cutter 13 stops rotating while the drive current is supplied from the battery 27 due to grass becoming entangled with the cutter 13, the motor output shaft 26 is moved by the slip of the clutch shoe 40 against the clutch drum 33. The motor continues to rotate and an overcurrent is prevented from flowing through the electric motor 19. By controlling the electric power supplied to the electric motor 19, the number of rotations and the direction of rotation of the motor output shaft 26 can be freely controlled.

  FIG. 8A is an enlarged perspective view showing a lock release switch provided on the handle shown in FIG. 1B, and FIG. 8B is a circuit diagram showing a motor reverse rotation circuit having the lock release switch. . A motor adjuster 46 having an adjustment dial 44 for controlling the motor rotation speed and a lock release switch 45 for switching the rotation direction is detachably mounted near the grip portion of the handle 16. The motor adjuster 46 has a holder 47 that is detachably attached to the handle 16, and in the illustrated case, the holder 47 has an attachment band 48 having a substantially C-shaped cross section. The notch 48a can be expanded. Bolts 49 are inserted into the notches 48a. After the handle 16 is fitted from the notches 48a, the bolts 49 are inserted into the notches 48a and fastened using the nuts 50. Thus, the motor adjuster 46 can be detachably attached to the handle 16.

  A variable resistor (not shown) is incorporated in the adjustment dial 44, and the drive current supplied from the battery 27 to the electric motor 19 by changing the resistance value of the variable resistor by rotating the adjustment dial 44. The number of rotations of the electric motor 19 can be adjusted by changing. By adjusting the rotation speed of the electric motor 19, the rotation speed of the cutter 13 can be adjusted via the driven shaft 11.

  The motor adjuster 46 is connected to the electric motor 19 through a cable 51. When the electric motor 19 is attached to the operation arm 10, as shown in FIG. When the engine 18 is attached to the operation arm 10 detachably, the motor adjuster 46 is detached from the handle 16 as shown in FIG. As shown in FIG. 8B, the lock release switch 45 is always connected to the motor normal rotation contact by a spring member (not shown). When the lock release switch 45 is pushed in, the reverse contact of the motor drive circuit becomes conductive, The electric motor is reversely rotated only while the lock release switch 45 is pushed.

  In the illustrated case, the lock release switch 45 is a push button type switch incorporating a spring member, and is normally held at the forward contact of the motor reverse rotation circuit as shown in FIG. 8B. When pressed, the electric motor 19 is temporarily rotated in contact with the reverse contact. When the pressing state is released and the lock release switch 45 returns to the original position, the reverse contact is opened as shown in FIG. 8B so that the forward contact contacts and the motor output shaft 26 rotates forward again. It has become. The reverse rotation circuit is not limited to the case shown in the figure, and once the lock release switch 45 is pressed, the motor output shaft 26 is reversely rotated by a predetermined rotation number, for example, one rotation, or the motor output shaft is rotated for a few seconds. 26 may be reversed. Further, the shape and structure of the lock release switch 45 are not limited to those shown in the figure, and any slide type, lever type or rotary type switch can be used as long as it can send a reverse current to the electric motor 19 when operated by an operator. Etc.

  In such a brush cutter, the operating arm 10 can be mounted with the engine 18 to perform the cutting operation, and the operating arm 10 can be mounted with the electric motor 19 to perform the cutting operation. When the cutter 13 is driven to rotate by the electric motor 19 and the cutting operation is performed, when the cutter 13 is locked and the cutter 13 is locked and the rotation stops when the cutter 13 is entangled with the cut leaves, the lock release switch 45 is operated. By doing so, the rotation direction of the cutter 13 can be reversed over a predetermined rotation number or time via the motor output shaft 26 of the electric motor 19. As a result, the cut leaves and the like entangled with the cutter 13 can be removed safely and easily, and workability can be improved. By mounting the motor adjuster 46 near the grip portion, the lock release switch 45 can be operated with the fingertip while the handle 16 is held, and the unlocking operation of the cutter 13 can be easily performed.

  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, the present invention can also be applied to a direct acting type brush cutter or a type of brush cutter in which a driving source and a cutter are mounted on a traveling carriage.

(A) shows a state where the engine is mounted on the brush cutter body, and (B) shows a state where the electric motor is mounted on the brush machine body. It is an expanded sectional view which shows a part of brush cutter shown in FIG. (A) is a front view of the engine, (B) is a side view of the engine shown in FIG. 3 (A). It is an expanded sectional view which shows a part of brush cutter shown in FIG.1 (B). (A) is a front view of an electric motor, (B) is a side view of the electric motor shown to FIG. 5 (A). (A) is a front view of a driven side joint, (B) is a side view of the driven side joint shown in FIG. 6 (A). It is a cross-sectional view in FIG. (A) is an enlarged perspective view showing a lock release switch provided on the handle shown in FIG. 1 (B), and (B) is a circuit diagram showing a motor reverse rotation circuit having a lock release switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Operation arm 13 Cutter 16 Handle 17 Driven side joint 18 Engine 19 Electric motor 30 Engine output side joint 31 Motor output side joint 45 Lock release switch

Claims (3)

A brush cutter body that is rotatably connected with a driven shaft that has a cutter connected to the tip and a driven side connecting portion at the other end, and an electric motor that is detachably attached to the brush cutter body and drives the cutter in both forward and reverse directions. And
An engine output side joint provided with an output shaft of the engine and connected to the driven side connecting portion, and a drive side provided with an output shaft of the electric motor and connected to the driven side connecting portion The brush cutter body is provided with a driven side joint that is selectively detachably attached to any of the motor side joints in which the connecting portions are incorporated,
When the cutter driven by the electric motor is locked in a state where the electric motor is mounted on the brush cutter body, a lock release switch for reversing the cutter is detachably attached to the brush cutter body. A brush cutter characterized by being mounted.   2. The brush cutter according to claim 1, wherein the brush cutter body is formed by a hollow bar-shaped operating arm into which a handle gripped by an operator is provided at a central portion in a longitudinal direction and the driven shaft is inserted. Payment machine.   The brush cutter according to claim 2, wherein the lock release switch is provided on a holder that is connected to the electric motor via a cable and is detachably attached to the handle.

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