JPH0787731B2 - Self-propelled brush cutter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a self-propelled brush cutter.

<Prior Art> The brush cutter main body is provided with a cutting blade that rotates about the vertical axis, and a traveling device that is rotationally driven about the horizontal axis. The forward / reverse motor drives the traveling device in the forward / reverse direction. In the self-propelled brush cutter provided with, a manual operating means such as a manual switch for giving a forward / reverse rotation command to the forward / reverse motor, and an automatic instruction means for alternately giving a forward / reverse rotation instruction to the forward / reverse motor every predetermined time. Is provided, and the manual mode by the manual operation means and the automatic mode by the automatic command means are switched by an automatic manual changeover switch. In this case, by switching to the automatic mode, the brush cutter main body can be automatically repeated left and right or front and back in a zigzag manner, whereby the brush cutting operation can be easily and smoothly performed.

<Problems to be Solved by the Invention> However, in the conventional case, when the automatic mode is set, unless the automatic manual changeover switch is switched to the manual mode side, the brush cutter main body is driven by alternating forward and reverse rotation of the forward and reverse motors. In order to keep repeating zigzag running from side to side or forward and backward, if there is an obstacle such as a stone in the running direction, operate the automatic manual changeover switch to change the mode from automatic mode to manual mode once in order to avoid the obstacle. After switching, it is necessary to manually operate the manual operating means so that the vehicle travels to the opposite side of the obstacle, and then switch the automatic manual changeover switch to the automatic mode side again, which is very troublesome to operate, and the obstacle is obstructed. There was a great fear of failing to avoid.

In view of the above problems, the present invention can be easily and smoothly run in the manual mode during the work in the automatic mode,
For example, an obstacle such as a stone can be easily and surely avoided, and the reaping work can be performed easily and smoothly.

<Means for Solving the Problem> The technical means of the present invention for solving the technical problem is a cutting blade body 7 that rotates in the brush cutter main body 1 about the vertical axis.
Is provided, and a traveling device 6 that is rotationally driven about the horizontal axis is provided, and a forward / reverse motor 9 that drives the traveling device 6 in the forward / reverse direction is provided, and a manual operation unit that gives a forward / reverse command to the motor 9. The forward / reverse motor 9 is provided with 103.
Automatic command means for alternately giving forward / reverse rotation commands every predetermined time
In the self-propelled brush cutter provided with 121, the automatic manual switching means 113 for switching between the manual mode by the manual operation means 103 and the automatic mode by the automatic command means 121, by the switching of the automatic manual switching means 113. In the automatic mode, the manual mode priority means 153 is provided to drive the forward / reverse motor 9 in the forward / reverse direction according to the operation of the manual operation means 103 only while the manual operation means 103 is operated.

<Operation> When the automatic manual switching means 113 is switched to the automatic mode and the manual operation means 103 is operated while working in the automatic mode by the automatic command means 121, the manual mode priority means 153 operates and the manual operation means In response to the operation of 103, the forward / reverse motor 9 is temporarily driven in the forward / reverse direction.

Then, when the operation of the manual operation means 103 is released, the mode is switched to the automatic mode by the automatic command means 121 again, and the forward / reverse motor 9 repeats the forward / reverse drive for each predetermined period by the automatic mode.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 4 to FIG. 8, 1 is a main body of a brush cutter, and has a steering handle 4 formed by connecting a direct rod 2 and a 2 or 3 rod continuously.
The handle 4 extends rearward as an upward inclination, and has a grip 5 on the bifurcated rod 3.

Reference numeral 6 denotes a traveling device that is rotationally driven about a horizontal axis, is provided on the lower side of the brush cutter main body 1, and includes uniaxial two-wheel drive wheels.

Reference numeral 7 denotes a cutting blade, which is provided on the front side of the main body 1 of the brush cutter so as to be rotatable around the vertical axis, and is driven to rotate by an engine 8. The engine 8 is arranged above the main body 1 of the brush cutter. ing.

Reference numeral 9 denotes a forward / reverse motor, which is attached to the front and one side of the main body 1 of the brush cutter by a support bracket 10. The motor 9 is supplied with power from an electric generator provided in the engine 8 via an electromagnetic clutch or the like, and travels. The device 6 is driven in forward and reverse directions.

Reference numeral 11 denotes a connecting cylinder, which connects the engine 8 and the transmission case 12 for the cutting blade body 7, and as shown in FIGS. 4 and 5.
The engine 8 extends forward from the front side with a downward inclination, and a pair of left and right connecting arms 11A extends downward in the middle of the connecting tube 11.

Reference numeral 13 denotes an engine output shaft, one end of a cutting blade transmission shaft 14 inserted in the linkage cylinder 11 is interlocked and coupled by a coupling 15, and the other end of the cutting blade transmission shaft 14 is a bevel gear built in the transmission case 12. It is linked to the mechanism 16.

Reference numeral 17 is a cutting blade shaft, which is rotatably supported by the transmission case 12 about the vertical axis and is interlockingly connected to a bevel gear mechanism 16. The cutting blade body 7 is attached to the lower end side of the cutting blade shaft 17 with bolts 18 or the like. ing.

Reference numeral 19 denotes a support base, which includes an inverted L-shaped substrate 20 in a side view and a flat plate-shaped mounting plate 21 protruding from the substrate 20 and having a substantially fan shape in a side view. As shown in the figure, the upper surface side of the substrate 20 is attached to the front upper surface of the brush cutter main body 1 by the bolt 22.
The mounting plate 21 is attached by the bolt 23, and the mounting plate 21 is attached by the bolt 23.
It is arranged below 11 under the shape of a front protrusion.

The pair of left and right connecting arms 11A installed below the connecting tube 11 is attached to the mounting plate 2
It is overlapped on the left and right of 1, connecting arm 11A and mounting plate 21
And the lower end side is overlapped with a fulcrum shaft 24 so that the cutting blade body 7 side is centered on the fulcrum shaft 24 with respect to the brush cutter main body 1 and is indicated by an arrow C in FIG. As shown in the drawing, they are connected so as to be bendable in the vertical direction.

Reference numeral 25 is a refraction angle adjusting means, and on the arc line centered on the fulcrum shaft 24, adjusting holes 26 are formed in the mounting plate 21 at a predetermined pitch,
Fixing holes 27 that respectively match the adjusting holes 26 are formed in the connecting arm 11.
As shown in FIG. 6, the connecting arm 11A on the side farther from the motor 9 is provided with a lock pin 28 which can be inserted into and removed from the fixing hole 27 and each adjusting hole 26, as shown in FIG.

As shown in FIG. 6, the lock pin 28 is slidably fitted in a guide cylinder 30 which has a guide collar 29 integrally and is fixed to the connecting arm 11A. The lock pin 28 is fitted in the guide cylinder 30 in the engaging direction. A coil spring 31 for urging is installed inside.

The lock pin 28 can be remotely operated to be unlocked against the coil spring 31 by a lever 33 that can be grasped by the handle grip 5 via a Bowden cable 32 including an inner wire and an outer wire. .

The first transmission mechanism 34 for traveling is built in the first transmission case 35 which is the main body 1 of the brush cutter.

The first transmission mechanism 34 comprises a worm 36 and a worm gear 37 that meshes with the worm 36. The worm 36 is formed by connecting the output shaft 38 of the motor 9 and the worm shaft 40 with a coupling 39 as shown in FIG. , Forward / reverse rotation is interlocked with forward / reverse driving of the motor 9.

As shown in FIG. 7, the worm gear 37 is housed in the first transmission case 35 so that it can freely rotate forward and backward about the axis of the worm 36 by the engagement of the worm 36, and the lower portion of the first transmission case 35 via the connecting cylinder shaft 41 and the bearing 42. Supported by boss 43.

Reference numeral 44 denotes a worm case. A bolt 45 shown in FIG. 4 is attached to cover one side opening of the first transmission case 35, and the worm shaft 40 is attached to the bearing 47 at the bulging portion 46 of the worm case 44. Supported by.

It should be noted that, as shown in FIG. 4, the motor 9 is arranged in a vertically inclined shape.

48 is a lower transmission case, and as shown in FIG.
It is composed of a bowl-shaped case portion 49 fixed to the lower end of 42 and a lid body 50 for covering the case portion 49. The lower transmission case 48 has a traveling bevel gear mechanism 51 built therein, and the bevel gear mechanism 51 and the worm gear. 37 and 37 are linked by a transmission shaft 52.

The transmission shaft 52 is inserted into the connecting cylinder shaft 41 and is supported by sleeve type bearings 53 and 54 so as to be rotatable around the shaft center.

Reference numeral 55 denotes an axle, which has a reduction gear of the bevel gear mechanism 51, is supported by bearings 56 at both ends in the axial direction of the lower transmission case 48, and is rotatable about a horizontal axis.

Wheel disks 57 are fitted and fixed to both axial ends of the axle 55, and a wheel body 58 made of rubber, plastic, or the like is fitted and fixed to the rim of each wheel disk 57, and a uniaxial two-wheel drive is provided therein. The traveling device 6 including the wheels 59 is configured.

The brush cutter main body 1 and the traveling device 6 are rotatable relative to each other about a vertical axis within a range of 90 degrees. Here, with respect to the cutting blade body 7 provided on the front side of the brush cutter main body 1. The drive wheel 59 is freely turnable between a forward position where it can move forward and backward (FIG. 4) and a lateral position where it can move left and right (FIG. 9).

Reference numeral 60 denotes a wheel turning and positioning mechanism, and as shown in FIGS. 6 and 7, a connecting cylinder shaft on the lower side of the first transmission case 35.
The boss cylinder 62 of the positioning lever 61 is fitted over the 41, and the positioning plate 63 is fixed to the vertical side wall of the worm case 44 with bolts 64.
A positioning lever 61 is detachably attached to 65 and 66.

The positioning lever 64 has a bending portion 67 formed of a coil spring in the middle thereof as shown in FIG. 7, and the grip of the operating lever 61 is moved below the bending portion 67 to move the lever 61 to the positioning recesses 65 and 66. When the lever 61 is disengaged and the relative angle of the lever 61 is changed in the direction of arrow D in FIG. 6 within a range of 90 degrees, the lever 61 can be positioned at the forward position E and the lateral position F.

This turning operation is performed by operating the lever 61 in the direction of arrow D with the positioning lever 61 disengaged.

Reference numeral 68 denotes a steering handle turning / positioning mechanism for turning the steering handle 4 between the positions G and H shown in FIG. It locks to.

Here, at the position G, the cutting blade bodies 7 are arranged in series on the front side of the steering handle 4, and at the position H, the cutting blade bodies 7 are arranged on one side of the steering handle 4 so as to project laterally.

As shown in FIGS. 7 and 8, this positioning mechanism 68 has a handle holder 70 having an L-shaped cross section having a fitting hole 69, and an L-shaped cross section attached to the elevation wall of the holder 70 with a bolt 71. A guide plate 72 is provided, and a protruding portion 73 around the vertical axis is formed on the upper surface side of the first transmission case 35. The fitting hole 69 is rotatably fitted into the protruding portion 73, and the guide plate 72 is provided. Are opposed to the lower surface side of the first transmission case 35.

An arcuate elongated hole 74 centered on the vertical axis is formed in the guide plate 72, and both ends of the elongated hole 74 serve as positioning portions 75, and lock bolts 76 are fitted into the positioning portions 75. There is.

An operating lever 77 having flanges 78 at both ends is slidably inserted into the head of the lock bolt 76 in an orthogonal shape.
The screw portion of 76 is fastened / releasable to the two locking female screw portions 79 formed on the lower surface side of the first transmission case 35.

That is, in order to turn the handle 4 between the position G and the position H, the operation lever 77 is rotated in the arrow J direction as shown in FIG. 8, and the operation lever 77 in the virtual position is slid to the solid line position. When the screw part of the lock bolt 76 is loosened from the female screw part 79 by rotating the lock bolt 76 again in the direction of the arrow J, the lock bolt 76
When the handle 4 is rotated in the direction of the arrow I in FIG. 6 in this state, the lock bolt 76 is guided through the long hole 74, and furthermore, the projection 73 and the fitting hole 69 are guided. The handle 4 is turned 90 degrees from the position G to the position H, and after this turning, the lock bolt 76 is fastened to the female screw portion 79 and locked.

In FIG. 7, reference numeral 80 denotes a boss for the female screw portion 79, and the straight rod 2 of the handle 4 is attached to the handle holder 70.

In addition, in FIG. 5, 81 indicates a bowl-shaped skid, and the cutting blade body 7 is detachably attached to the skid 81 with bolts 82.
The cutting blade body 7 has a cutting blade 7A as shown in FIG.

The cutting blade 7 has a step portion 7B as shown in FIG. 5, and the cutting height can be adjusted within the range between the solid line and the imaginary line in FIG. Is.

1 to 3 show a control circuit for the forward / reverse motor 9, of which FIG. 1 shows a circuit state when a normal rotation manual switch 101 described later is turned on in the automatic mode, and FIG. 2 shows an automatic mode. FIG. 3 shows a circuit state when the reverse rotation manual switch 102 described later is turned on in the automatic mode.

1 to 3, 101 is a forward rotation manual switch for giving a forward rotation command to the forward / reverse motor 9, 102 is a reverse rotation manual switch for giving a reverse rotation command to the forward / reverse motor 9, and these manual switches Manual operation means 1 by switches 101 and 102
03 is configured. As shown in FIG. 11, the manual switches 101 and 102 are attached to a pair of left and right grips 5 of the forked rod 3, respectively.

106 is an automatic manual changeover switch, 107 is an OR circuit, 108 is a NOT circuit, and 109 is an AND circuit. 110 is a relay circuit, which has relay switches 111 and 112, and is configured to be excited when the high voltage H is input from the AND circuit 109 to attract the movable contact a of the relay switches 111 and 112 from the fixed contact c to the fixed contact b. ing. When the low voltage L is input from the AND circuit 109, the movable contacts a of the relay switches 111 and 112 are demagnetized and fall to the fixed contact c side. The automatic manual changeover switch 106, OR circuit 107, NOT circuit 108 and AND circuit 109
Further, the relay circuit 110 constitutes an automatic manual switching means 113 for switching the circuit between the manual mode and the automatic mode. As shown in FIGS. 11 and 12, the automatic manual changeover switch 106 is a speed setting device for setting the rotation speed of the main switch 115 forward / reverse motor 9 on a panel plate 114 mounted in the middle of the bifurcated rod 3. It is mounted as a unit together with a dial 116 and a time setting dial 117.

A timer 119 is configured to alternately output the high voltage H and the low voltage L every predetermined time, and the predetermined time for switching from the high voltage H to the low voltage L and from the low voltage L to the high voltage H The time setting dial 117 can be arbitrarily set. 120 is a NOT circuit. The timer 119 and the NOT circuit 120 constitute an automatic command means 121 which alternately gives a forward / reverse command to the forward / reverse motor 9 every predetermined time.

123,124 is a monostable multivibrator, 125,126 is a resistor R ₁
And a condenser C ₁ and an integrator circuit 127,128 are differentiating circuits having a condenser C ₂ and a resistor R ₂ , and the monostable multivibrator 123,124 receives a high voltage H at each input terminal A thereof. The elements 123 and 124 (output terminal Q) are turned on (the high voltage H is output).

131, 132, 133, 134 are NOT circuits, 135, 136 are NAND circuits, 137, 1
38 is an RS flip-flop circuit, and RS flip-flop circuits 137 and 138 are one of the flip-flop circuits 13
The other flip-flop circuits 138 and 137 are not turned on (the output is the high voltage H) unless the 7,138 are turned off (the output is the low voltage L).

141 and 142 are transistors, and 143 and 144 are relay circuits. When the corresponding transistors 141 and 142 are turned on, they are excited to attract the movable contact a of the relay switches 145 and 146 from the fixed contact b to the fixed contact c side, and demagnetize by turning off the transistors 141 and 142. The movable contacts a of the relay switches 145 and 146
Is inclined toward the fixed contact b side.

147 is an AND circuit, 148 is a relay circuit, and the relay switch 14
It has 9,150, 151, 152 and is configured to be excited when the high voltage H is inputted from the AND circuit 147 to attract the movable contact a of the relay switches 149, 150, 151, 152 from the fixed contact c to the fixed contact b. When the low voltage L is input from the AND circuit 147, the relay circuit 148 is demagnetized and the relay switch 14
The movable contacts a of 9,150, 151, 152 are designed to fall to the fixed contact c side. The AND circuit 147 and the relay circuit 148 constitute the manual mode priority means 153 which drives the forward / reverse motor 9 in the forward / reverse direction according to the operation of the manual operation means 103 only while the manual operation means 103 is operated in the automatic mode. Has been done.

When weeding the weeds with the brush cutter having the above-mentioned configuration, the following is done.

FIG. 9 shows a state in which the drive wheel 59 is set in the horizontal position, in which the positioning lever 61 of the positioning mechanism 60 engages with the recess 66, and the cylinder shaft 41 is transmitted with the drive wheel 59 in the horizontal position. It is locked to the case 35 side so that it cannot rotate.

Therefore, when working, with the drive wheels 59 grounded,
The operator holds the pair of grips 5 of the handle 4 so as not to fall to the left and right, keeps the cutting blade body 7 rotated by the power from the engine 8, and rotates the cutting blade manual switch 101 of the motor 9 and the reverse rotation. While manually operating the manual switch 102 and the automatic manual changeover switch 106 to reciprocate the front side to the left and right, the cutting blade body 7 is rotated to mow. That is, when the motor 9 rotates in the forward direction, the drive wheel 59 rotates in the forward direction around the horizontal axis in the front-rear direction via the output shaft 38, the bevel gear mechanisms 34, 51 and the axle 55, and the front part of the brush cutter is shown. Since the side moves laterally (to the left), weeds and the like are mowed by the rotating cutting blade body 7. When the motor 9 rotates in the reverse direction after reaching the predetermined position in the left direction, the drive wheels 59 rotate in the reverse direction via the above-mentioned transmission system. Therefore, the front part side of the brush cutter moves to the right, and the weeds and the like are also cut by the rotation of the cutting blade body 7.

At this time, the axle 55 faces the front-back direction, but the drive wheels 59
When the operator switches from the normal rotation to the reverse rotation and from the reverse rotation to the normal rotation, if the worker slightly shakes the handle 4 side to the left and right, the drive wheels 59 move left and right and move forward diagonally, as shown in FIG. Since it moves in a zigzag pattern, you can mow over a certain width.

When cutting the brush cutter forward or backward, the drive wheels
Change the direction of 59 to the forward position. That is, since it is in the lateral position in FIG. 9, the positioning lever 61 is first disengaged from the engaging recess 66 against the spring 67, and the lever 61 is unlocked. Approximately in the opposite direction
Rotate 90 degrees. Then, the drive wheel 59 rotates from the lateral position to the front position via the cylindrical shaft 41, so that the positioning lever 61 is engaged with the engaging recessed portion 65 and the lever 61 is again fixed so as not to be rotatable. The drive wheel 59 is now in the forward position shown in FIG. 4 with the axle 55 facing left and right, and therefore the drive wheel 59
When 59 is rotated in the forward direction, it moves forward, so that the weeds and the like on the front side can be mowed by the cutting blade 7, as shown in FIG.

Even in this forward direction, if the handlebar 4 side is slightly swung left and right while the motor 9 is rotated forward and backward, as shown in FIG. 14, it is possible to move forward and backward while moving leftward or rightward in a zigzag manner.

Further, the steering handle 4 is turned from the position G to the position H,
If set as shown by the phantom line in FIG. 9, the cutting blade body 7 is laterally projected to one side of the drive wheel 59.
When 59 is moved forward, side cutting can be performed as shown in FIG.

Further, in this state of side cutting, when grasping the hand lever 33 and pulling out the lock pin 28 against the spring 31 via the wire 32, the attachment plate 21 is unlocked and the connecting arm 11A is unlocked. The blade body 7 side bends around the fulcrum shaft 24 in the direction of arrow C, the cutting blade body 7 enters a state along the slope L as shown in FIG. 10, and the lock pin 28 is locked in the predetermined adjusting hole 26. Then fix the waist break.

When the drive wheel 59 is moved forward in this state, the slope L along the longitudinal direction of the bank is cut.

Further, the handle 4 can be moved to the position G with the cutting blade 7 along the slope L, and the cutting operation can be performed by rotating the wheels 59 forward and backward as shown by the solid line in FIG.

Next, the manual switches 101, 102 or the automatic manual changeover switch 1
The circuit operation by the operation of 06 will be described. When the forward rotation manual switch 101 is turned on, the forward rotation manual switch 101 outputs a high voltage H as shown in FIG. At this time, when the reverse rotation manual switch 102 and the automatic manual changeover switch 106 are off, the outputs of the AND circuits 109 and 147 become the low voltage L and the relay circuits 110 and 148 are demagnetized, so the relay switch 11
The movable contacts a of 1,112,149,150,151,152 are set on the fixed contact c side.

As a result, the high voltage H is input from the forward rotation manual switch 101 to the monostable multivibrator 123, and after a certain time T ₁ , the voltage input from the relay switch 151 to the NAND circuit 135 becomes the high voltage H, and then the forward rotation manual operation is performed. Even if the pressing of the switch 101 is released, the output Q voltage of the monostable multivibrator 123 holds the high voltage H for a certain period with a time constant determined by the capacitor C ₁ and the resistor R ₁ . On the other hand, the high voltage H is input from the NOT circuit 133 to the flip-flop 137, and the low voltage L is input from the NOT circuit 134 to the flip-flop 138. Therefore, the output of the flip-flop 137 becomes the high voltage H, and
The output of the flip-flop 138 becomes the low voltage L, and the transistor 141 is turned on.

Therefore, when the normal rotation manual switch 101 is turned on, the output voltage of the normal rotation manual switch 101, the output Q voltage of the monostable multivibrator 123, the voltage at the point B, the flip-flop 1
The input voltage of 37, the output Q voltage of the flip-flop circuit 137, the output Q voltage of the flip-flop 138, the forward rotation current I _CW and the reverse rotation current I _CCW flowing in the motor 9 are in the states shown in FIG. The reverse motor 9 is driven to rotate normally.

Next, when traveling the brush cutter main body 1 in the automatic mode, when the automatic manual changeover switch 106 is turned on as shown in FIG. 2, the automatic manual changeover switch 106 is shown as shown in FIG.
Becomes high voltage H. At this time, the manual switch for forward rotation
When 101 and the manual switch for reverse rotation 102 are off, the output of the AND circuit 109 is high voltage H and the output of the AND circuit 147 is low voltage L.
And the relay circuit 110 is excited and the relay circuit 1
Since 48 is demagnetized, the movable contacts a of the relay switches 111 and 112 are set to the fixed contact b side respectively, and the relay switch 14
The movable contacts a of 9,150, 151, 152 are held on the fixed contact c side.

As a result, the high voltage H is alternately output from the timer 119 every predetermined time.
And a low voltage L output is a monostable multivibrator 12
A voltage obtained by inverting the voltage input to the monostable multivibrator 123 by the NOT circuit 120 while inputting to 3 is input to the monostable multivibrator 124.

Therefore, when the automatic manual changeover switch 106 is turned on, the output voltage of the timer 119, the output Q voltage of the monostable multivibrator 123, the output Q voltage of the monostable multivibrator 124, the forward rotation current I _CW to the forward / reverse motor 9, and the reverse rotation. For current I
_CCW becomes as shown in FIG.
Are alternately turned on every predetermined time, and the forward / reverse motor 9 alternately repeats forward rotation driving and reverse rotation driving.

Further, when the automatic manual selector switch 106 is turned on and the brush cutter main body 1 is traveling in the automatic mode, if the reverse rotation manual switch 102 is turned on as shown in FIG. As shown, the output of the AND circuit 147 is the high voltage H.
And the output of the AND circuit 109 becomes a low voltage L, the relay circuit 110 is demagnetized, and the relay circuit 148 is excited.
The movable contacts a of the relay switches 111 and 112 are fixed contacts c, respectively.
And the movable contacts a of the relay switches 149, 150, 151, 152 are set to the fixed contacts b.

As a result, the high voltage H is input from the forward rotation manual switch 101 to the NAND circuit 135 via the NOT circuit 131, and the low voltage L is input from the reverse rotation manual switch 102 to the NAND circuit 136 via the NOT circuit 132, Further, the low voltage L is input to the flip-flop 137 via the NOT circuit 133, and the high voltage H is input to the flip-flop 138 via the NOT circuit 134.

Therefore, if the reverse rotation manual switch 102 is turned on during the automatic mode, the output voltage of the reverse rotation manual switch 102, the output Q voltage of the flip-flop 137, the output Q voltage of the flip-flop 138, the forward rotation current to the forward / reverse motor 9 are generated. The I _CW and the reverse current I _CCW have waveforms as shown in FIG. 19, and the transistor 142 is turned on in the manual mode and the forward / reverse motor 9 is driven in the reverse direction only while the reverse manual switch 102 is turned on. Then, when the pressing of the reverse rotation manual switch 102 is released to return it to the off state, the circuit state returns to the automatic mode as shown in FIG. 2, and the forward / reverse motor 9 repeats the forward / reverse driving in the automatic mode every predetermined time. .

Although the cutting blade 7 is rotated by the engine 8 in the direction of arrow K in FIG. 6, a clutch is provided on the output side of the engine 8 to activate the motor 9 by the generator while cutting the cutting blade 7 Is stopped so that the vehicle can run on the road.

In FIG. 20, the output of the engine 8 is driven by the winding transmission device 91 to drive the cutting blade 7 around the vertical axis, and the motor 9 is arranged in the transmission case 35, that is, on the upper surface side of the brush cutter main body 1 with a vertical opening. , The pinion 92 is used to drive the gear 37 so that the drive wheel 59 can be rotated forward and backward.

In FIG. 20, 93 is a fuel tank provided on the engine side.

The refraction angle adjusting means 25 sets the fulcrum shaft 24 as low as possible to adjust the angle (90 in the embodiment).
)), The relationship between the cutting blade 7 and the traveling device 6 can be reduced. Further, the adjusting hole 26 may be an arcuate elongated hole centering on the fulcrum shaft 24, and the lock pin 28 may be a fastening bolt.

The cutting blade body 7 may be a swing type cutting blade 7A as shown in FIG. 21 or a saw tooth shape shown in FIG.

<Effects of the Invention> According to the present invention, in the automatic mode by switching the automatic manual changeover switch 106, the forward / reverse motor 9 is rotated in the forward / reverse direction according to the operation of the manual operation means 103 only while the manual operation means 103 is operated. Since the manual mode priority means 153 for driving is provided, when the brush cutter main body 1 is zigzag-traveled in the automatic mode, for example, if there is an obstacle such as a stone on the traveling direction side, the manual operation means 103 is simply used. By operating, it becomes possible to easily travel in the manual mode during the work in the automatic mode, and obstacles can be easily avoided. Moreover, after that, the operation in the automatic mode can be resumed only by returning the operation of the manual operation means 103 to the original state, and the mowing work can be performed extremely easily and smoothly.
Its practical effect is remarkable.

[Brief description of drawings]

1 to 19 show an embodiment of the present invention, FIGS. 1 to 3 show a control circuit for a forward / reverse motor, and FIG. 1 shows a case where a forward rotation manual switch is turned on in a manual mode. The circuit state, FIG. 2 shows the circuit state in the automatic mode, and FIG. 3 shows the circuit state when the reverse rotation manual switch is turned on in the automatic mode. 4 is an overall side view when moving forward and backward, FIG. 5 is a detailed side view of the cutting blade body part, FIG. 6 is a plan view of FIG. 5, and FIG. 7 is a line AA of FIG. Partial deployment elevation sectional view,
FIG. 8 is a plan sectional view taken along the line BB of FIG. 7, FIG. 9 is an overall side view when moving left and right, FIG. 10 is a side view when cutting an inclined surface, and FIG. 11 is a handle part. A plan view, FIG. 12 is a configuration diagram of a manual switch and a unit panel portion, and FIGS. 13 to 16
FIG. 17 is an explanatory diagram of a working state, and FIGS. 17 to 19 are waveform diagrams for explaining the circuit operation. FIG. 20 is a side view showing another embodiment, and FIGS. 21 and 22 are plan views showing other two examples of the cutting blade. 1 ... brush cutter main body, 6 ... traveling device, 7 ... cutting blade body,
9 ... Forward / reverse motor, 103 ... Manual operation means, 113 ... Automatic manual switching means, 121 ... Automatic command means, 153 ... Manual mode priority means.

Claims (1)

[Claims] 1. A brush cutter main body (1) is provided with a cutting blade body (7) that rotates about a vertical axis, and a traveling device (6) that is driven to rotate about a horizontal axis. A forward / reverse motor 9 for driving is provided, a manual operation means 103 for giving a forward / reverse command to the motor 9 is provided, and an automatic command means 121 for alternately giving a forward / reverse command to the forward / reverse motor 9 at a predetermined time is provided. In the self-propelled brush cutter provided with the automatic manual switching means 113 for switching the manual mode by the manual operation means 103 and the automatic mode by the automatic command means 121, in the automatic mode by the switching of the automatic manual switching means 113. A self-propelled brush cutter characterized by being provided with a manual mode priority means 153 for driving the forward / reverse motor 9 in the forward / reverse direction according to the operation of the manual operation means 103 only while the manual operation means 103 is operated. Machine.