JP6643811B2 - Brush cutter - Google Patents

Description

  The present invention relates to a mower such as a lawn mower and a lawn mower, and more particularly, to a tubular support rod provided with a cutter unit including a rotary blade and a motor for mowing at a front end thereof, and an electric cable passed through a pipe of the support rod. An electric cable passing through the pipe of the support rod is supplied to the motor and provided with a handle at a predetermined position of the support rod for a worker to grip the brush cutter during use. The device is devised so that it does not oscillate in the support rod tube due to vibration and vibrates itself or intermittently collides with the inner wall of the pipe, thereby promoting vibration and noise generation of the support rod.

  A cutter unit including a rotary blade and a motor is provided at the front end of the tubular support rod, and a handle is provided at the rear or midway of the support rod as a brush cutter for mowing weeds in parks and banks and garden lawns. Hold the handle with both hands, hold the support rod underneath, move the cutter blade of the cutter unit back and forth along the ground, move it back and forth, and mow the weeds and grass growing there There are types, which are widely used. In this type of brush cutter, an electric cable is provided in the support rod to supply a motor at the front end of the support rod from the rear end side of the support rod to a power source of a battery power supply or a commercial power supply through an operation switch. It has been inserted. However, in many cases, the electric cable generally only passes through the pipe of the support rod casually, and no special guide member or support member is provided.

  In the use state of this type of brush cutter, the rotating blade is rotated at a high speed by the motor, so that the supporting rod vibrates and the electric cable inserted into the pipe of the supporting rod swings in the rod. It vibrates itself or intermittently collides with the inner wall of the support rod, promoting vibration and noise generation of the support rod, transmitting unpleasant vibration to the user's hand and transmitting noise to the neighborhood. Dissipation also leads to fatigue and disconnection of the electrical cable. In particular, the electric cable may resonate at a specific frequency depending on the length, mass, tension, and arrangement of the electric cable inserted into the pipe of the support rod, and vibration and noise of the support rod at that frequency may occur. Becomes larger. Empirically, if the vibration around 10 Hz is large to some extent, it seems that the operator holding the brush cutter feels very uncomfortable.

  Furthermore, in the case of a brushless DC motor that has recently been adopted, between the motor in the cutter unit arranged at the front end of the support rod and the power supply unit and control unit arranged at the rear end of the support rod, for example, Numerous (eg, eight) electrical cables, including control wires that feed each of the three pole field windings, are passed through the support rod tube in the form of a bundle or in the form of a multi-core molded wire. Since the linear density of the electric cable is large, the vibration energy when the electric cable swings is large, and the collision energy of the support rod with the pipe wall is also large. Therefore, the vibration transmitted to the support rod is correspondingly large.

JP 2014-233216 A

  The present invention relates to a brush cutter in which a cutter unit including a rotary blade and a motor is provided at a front end of a tubular support rod, and an electric cable is inserted into a pipe of the support rod. An object of the present invention is to provide a brush cutter in which vibration and noise due to the swing movement of the electric cable are not generated, and fatigue of the electric cable does not occur.

In order to solve the above-mentioned problems, a brush cutter according to the present invention includes a support rod having a tubular rod shape having a front end, a rotary blade disposed at the front end of the support rod, and a rotary blade for mowing. A cutter unit including a motor for driving the blade, an electric cable inserted into a tube of the support rod to supply power to the motor, and a handle disposed on the support rod for an operator to grip during use. Wherein the motor is a brushless DC motor, and the electric cable is a bundle of wires including a control line for supplying power to each of the three-pole field windings of the brushless DC motor, between the electrical cable and the support rod in the tube wall, the swing suppressing elastic body of said electrical cables, by comprising interposed at intervals at appropriate intervals in the direction in which the support rod extends And it features.

  In the brush cutter of the present invention, when the elastic body is interposed between the electric cable and the inner wall of the pipe of the support rod at the front end of the support rod, the work of the manufacturing process is simple, and the swing movement of the electric cable is reduced. This is preferable because it can be effectively suppressed.

  In the brush cutter according to the present invention, when the elastic body is configured as a cylindrical member provided around the outer periphery of the electric cable, the electric cable can be supported by floating from the inner wall of the pipe of the support rod. Further, in this case, if the outer diameter of the cylinder is smaller than the inner diameter of the inner wall of the pipe of the support rod, it is easy to pass the electric cable through the elastic body in advance and then pass the combined cable through the support rod. The work of the process is easy to carry out, which is preferable. Conversely, if the inner diameter of the cylindrical shape is larger than the outer diameter of the electric cable, the elastic body is passed through the support rod in advance, and the electric cable can be easily passed through the hole of the elastic body. The work in the manufacturing process is easy and is preferable.

  In the brush cutter of the present invention, when the elastic body is a columnar member and is inserted between the electric cable and the inner wall of the support rod on one side of the electric cable, after the electric cable passes through the support rod tube, Since the elastic body can be packed by the method, the work in the manufacturing process is easy to perform, which is preferable.

  In the brush cutter according to the present invention, it is preferable that the elastic body is made of a flexible material such as polyurethane foam which easily changes its volume, because it can effectively absorb the swinging movement of the electric cable.

  According to this invention, since the elastic body is interposed between the electric cable inserted into the pipe of the support rod and the inner wall of the pipe of the support rod, vibration caused by rotation of the rotary blade driven by the motor is provided. The electric cable can be prevented from oscillating in the pipe of the support rod and vibrating itself or colliding against the inner wall of the pipe, so that the support rod does not vibrate unnecessarily or generate noise, and Failure due to cable fatigue is reduced.

It is a perspective view showing the whole appearance of the brush cutter by one embodiment of the present invention. It is sectional drawing which shows one form of the structure near the front end part of the support rod in the brush cutter by one Embodiment of this invention. It is sectional drawing which shows another structure of the structure near the front end part of the support rod in the brush cutter by one Embodiment of this invention. It is sectional drawing which shows another form of the structure near the front end part of the support rod in the brush cutter according to one Embodiment of this invention. It is sectional drawing which shows another form of the structure near the front end part of the support rod in the brush cutter according to one Embodiment of this invention.

  An embodiment of a brush cutter according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an overall image of a brush cutter according to an embodiment of the present invention. This embodiment is a brushless DC motor-type brush cutter using a battery power supply. In this brush cutter, a cutter unit 2 is disposed at a front end of a support rod 1 having a tubular rod shape, and the cutter unit 2 includes a motor (hidden in the figure) inside a cutter unit housing 20. A rotary blade 21 driven by a motor is provided below and outside the housing 20. A protective cover 6 located behind the cutter unit 2 is further attached to the front end of the support rod 1. At the rear end of the support rod 1, a rear end unit 3 is provided. The rear end unit 3 has a structure in which a battery 31 as a power supply is detachably attached, and a control circuit as necessary. Built-in. Although hidden in FIG. 1 and not visible, an electric cable for supplying power from the rear end unit 3 to the cutter unit 2 is provided through the inside of the tube of the support rod 1. A handle 4 for an operator to grip the brush cutter 1 at the time of use is disposed near the middle of the support rod 1 at the rear, and the handle 4 includes a left-hand grip portion 41L, a right-hand grip portion 41R, and An operation unit 42 is provided. Further, the support rod 1 is provided with a shoulder strap mounting portion 5 at a position between the handle 4 and the rear end unit 3, so that a shoulder strap for hanging the brush cutter on the shoulder to support it in use can be attached. I can do it.

  Next, the elastic body inserted between the inner wall of the support rod 1 and the electric cable will be described. FIG. 2 is a cross-sectional view showing a structure near the front end of the support rod 1 in one mode in which an elastic body is inserted. The electric cable 11 is inserted through a tube of the support rod 1. A polyurethane foam 12, which is an elastic body, is packed into the gap between the inner wall of the tube and the outer peripheral surface of the electric cable 11 from the opening end 1a of the support rod 1 by a predetermined length L (for example, 200 mm). The polyurethane foam 12 is a soft foamed elastic body, is deformed by a relatively small force, and has an appropriately large internal loss at the time of deformation, so that the impact of the colliding member is appropriately absorbed and moderated. The front end of the support rod 1 is closest to the cutter unit 2 and is where vibration is transmitted to the support rod 1. The elasticity and internal loss of the polyurethane foam 12 provided in this part suppresses the electric cable 11 from damping. Works efficiently.

  In terms of the vibration damping effect, it is effective to provide the elastic body 12 around the electric cable 11 over the entire length of the support rod 1, and as a method for supporting the elastic body 12 after passing the electric cable 11 through the support rod 1. It is possible if an unfoamed resin liquid is poured into the pipe of the rod 1 and the resin liquid is foamed in the pipe of the support rod 1. The elastic body 12 is not limited to a cylindrical shape so that the electric cable 11 can pass therethrough, and as shown in FIG. The elastic body 12a having a columnar shape can be packed between the electric cable 11 and the inner wall of the pipe by pressing against one side of the wall. The work of the manufacturing process is facilitated, which is preferable.

  However, a manufacturing process is employed in which an unfoamed resin liquid is poured into the pipe of the support rod 1 after the electric cable 11 is passed through the support rod 1, and the resin liquid is foamed in the pipe of the support rod 1. In this case, it will be inconvenient in that it is difficult to repair or replace the electric cable 11 at a later date. As a method for solving the problem, as shown in FIG. A cylindrical elastic body 12b having a diameter D2 is attached in advance over the entire length of the electric cable 11 or at appropriate intervals, or around the open end 1a of the support rod 1 around the outer periphery of the electric cable 11. The electric cable 11 with the elastic body 12b can be easily inserted into the tube of the support rod 1. Alternatively, as shown in FIG. 5, a cylindrical elastic body 12c having an inner diameter D3 larger than the outer diameter of the electric cable 11 may be supported on the inner wall of the support rod 1 over the entire length or at appropriate intervals. The electric cable 11 can be easily inserted later into the cylindrical space of the elastic body 12c by being attached to the vicinity of the opening end 1a of the rod 1 in advance in contact with the inner wall of the pipe. In this case, if a guide wire is passed through the cylindrical space of the elastic body 12c in advance, and the electric cable is drawn in with the guide wire, the manufacturing operation becomes easier. In any case, there is room for the electric cable 11 to swing in the tube of the support rod 1, but the range of movement is restricted, and even if a collision occurs, the elastic bodies 11b and 11c are interposed. As a result, the vibration damping effect is obtained.

  The embodiment described above is a brush cutter of the type in which the battery 31 is attached to the rear end unit 3. However, the brush cutter of the type in which the rear end unit 3 is provided with a connector for receiving an AC power from a commercial power supply is also supported. The present invention is useful because the electric cable is inserted into the pipe of the rod 1.

  As described above, according to the brush cutter of the present invention, the elastic body is interposed between the electric cable inserted into the support rod and the inner wall of the pipe of the support rod, so that the electric cable is prevented from swinging. In addition, since the electric cable does not directly collide with the inner wall of the pipe, vibration and noise of the support rod, which is unpleasant for the operator, are suppressed. When the elastic body is a soft foamed elastic body, the effect of suppressing vibration and noise is particularly remarkable.

  DESCRIPTION OF SYMBOLS 1 ... Support rod, 1a ... Open end of support rod, 2 ... Cutter unit, 3 ... Rear end unit, 4 ... Handle, 5 ... Shoulder strap mounting part, 6 ... Protective cover, 11 ... Electric cable, 12 ... Elastic body, Reference numeral 20: cutter unit housing, 21: rotary blade, 31: battery, 41L: left hand clip portion, 41R: right hand grip portion, 42: operating portion.

Claims (3)

A support rod having a tubular rod shape having a front end,
A cutter unit disposed at the front end of the support rod, including a rotary blade for mowing and a motor for driving the rotary blade,
An electric cable inserted into the tube of the support rod to supply power to the motor,
A brush cutter comprising: a handle disposed on the support rod for an operator to grip during use;
The motor is a brushless DC motor,
The electric cable is a bundle of wires including a control line for supplying power to each of the three-pole field windings of the brushless DC motor,
Between the electric cable and the pipe inner wall of the support rod, an elastic body that suppresses the swing of the electric cable is interposed at appropriate intervals in the direction in which the support rod extends ,
The elastic body is interposed between the electric cable and the inner wall of the support rod at at least the front end of the support rod, and has a cylindrical shape provided around the outer periphery of the electric cable. Member
The brush cutter , wherein the elastic body has an outer diameter of the cylindrical shape smaller than an inner diameter of the inner wall of the pipe of the support rod . A support rod having a tubular rod shape having a front end,
A cutter unit disposed at the front end of the support rod, including a rotary blade for mowing and a motor for driving the rotary blade,
An electric cable inserted into the tube of the support rod to supply power to the motor,
A handle disposed on the support rod for an operator to grip during use;
In a brush cutter comprising:
The motor is a brushless DC motor,
The electric cable is a bundle of wires including a control line for supplying power to each of the three-pole field windings of the brushless DC motor,
Between the electric cable and the pipe inner wall of the support rod, an elastic body that suppresses the swing of the electric cable is interposed at appropriate intervals in the direction in which the support rod extends,
The elastic body, the is interposed between the electrical cable and at least the front end of the support rod and the inner wall of the support rod, exhibits a cylindrical shape provided surrounding the outer periphery of the electric cable Member
The brush cutter according to claim 1, wherein the elastic body has an inner diameter of the cylindrical shape larger than an outer diameter of the electric cable . The brush cutter according to claim 1 or 2,
The brush cutter, wherein the elastic body is a polyurethane foam .

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