JPS6050407B2 - Safety equipment for backpack-type brush cutters - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a backpack-type brush cutter in which a rotatable prime mover is fixedly held on the backpack frame when not in operation, and when the prime mover is started at the start of work, the motive power is not cut. This relates to a safety device that prevents accidental rotation.

In such backpack-type brush cutters, the prime mover is carried on the worker's back by means of a backpack frame, and the prime mover is rotatably mounted on the backpack frame, and a flexible rod portion that can be bent freely is used in the transmission system.

In addition, a centrifugal clutch is built into the power transmission system from the prime mover to the harvester, just like other brush cutters, so that when the throttle lever is operated to increase the prime mover's rotational speed, the mower automatically rotates. . Therefore, before starting work, the prime mover, operating rods, etc. are lowered to the ground, the prime mover is started, and then the prime mover is carried on one's back using a carrying frame. If left as is, it will not only be extremely difficult to perform the above-mentioned tasks, but also the mower will be attached to the mower via a transmission system, which may cause danger if they move together.

Additionally, the centrifugal clutch may engage immediately upon starting the prime mover to rotate the harvester. Although there is still little danger if the harvest is only rotating, it is extremely dangerous if the rotating harvest suddenly flies off in an unpredictable direction. By the way, the history of practical use of backpack-type brush cutters itself is still short, and the current situation is that sufficient safety measures have not been implemented to deal with the dangers peculiar to backpack-type brush cutters.

The present invention has been made in view of these circumstances, and includes a clutch housing that accommodates a centrifugal clutch on the motor side, which is provided with a drum locking device that locks the rotation of the clutch drum, and the drum locking device has a locking effect. By attaching a hook to the lock slider, bringing the clutch housing close to one side of the backpack frame, and engaging the hook with the backpack frame, the drum lock device locks the rotation of the clutch drum and fixes the prime mover to the backpack frame. To provide a safety device for a backpack-type brush cutter that simultaneously performs the following functions.

Embodiments of the present invention will be specifically described below with reference to the drawings.

First, referring to FIGS. 1 to 3, the overall outline of the backpack-type brush cutter according to the present invention will be explained. Reference numeral 1 denotes a backpack frame, and an upright portion 2a of a frame 2 that is approximately L-shaped when viewed from the side.
A back support 3 and a band 4 are attached to the body so that the person can carry it on his or her back. A prime mover 5 is mounted on the horizontal portion 2b, and a clutch housing 6 having a centrifugal clutch protrudes from the prime mover 5 to one side of the backpack frame 1, and a starter knob 5a of the prime mover 5 is provided on the other side. The housing 6 is mounted in such a manner that the housing 6 is pulled away from one side of the upright portion 2a of the backpack frame 1 at the time of starting.
Reference numeral 7 designates an elongated operating rod, which is made up of a rigid rod portion 7a made of metal and a flexible rod portion 7b connected by a holder 8, and the base end side of the flexible rod portion 7b is coupled to the clutch housing 6.

A cutting blade 10 is attached to the tip of the rigid rod portion 7a together with a gear case 9, a handle 11 and a grip 1'' are attached to a predetermined location in the middle of the operating rod 7, and a throttle lever 12 is attached just before the grip 1''. The cutting blade 10 is the gear case 9
The throttle lever 12 is connected to the prime mover 5 via a transmission system in the operating rod 7 and a centrifugal clutch in the clutch housing 6, and the throttle lever 12 is also connected to the prime mover 5 by a wire or the like so as to change its rotational speed. In Figures 4 and 5,
To describe in detail the prime mover 5 mounting portion of the backpack frame 1, the horizontal portion 2b of the backpack frame 2 forms a substantially U-shape in plan view;
A support plate 13 is horizontally protruded inward at three locations on the end opposite to the upright portion 2a of the horizontal portion 2b, and a triangular mounting base is mounted on the support plate 13 via a vibration-proof rubber cushion 14. 15 is fixed by a bolt/nut fastener 16.

An outline of the mounting base 15. A boss portion 15a is formed in the center to protrude upward, and a bearing 18 is housed in the boss portion 15a. It is rotatably assembled to the bearing 18, so that the prime mover 5 freely rotates horizontally, and vibrations transmitted from the prime mover 5 to the operator via the backpack frame 1 are reduced by the rubber cushion 14 and the like. Additionally, a torque spring 1 is provided around the mounting base boss portion 15a.
9 is attached, and one end thereof is locked to the mounting base 15 side, while the other end is left free and a cut-and-raised part 20 is provided protrudingly on the fixed plate 17 so as to be able to engage with this free end 19a. Then, the free end 19a of the torque spring 19 and the cut-and-raise 20 engage with each other in a predetermined range when the clutch housing 6 of the motor 5 that protrudes to the side of the backpack frame 1 approaches one side of the upright portion 2a. A spring force is applied to the fixed plate 17. Next, in FIGS. 6 to 8,
To describe in detail the connection between the clutch housing 6 and the flexible rod portion 7b, a centrifugal clutch is accommodated in the clutch housing 6, and the drum 2 of this centrifugal clutch is
One boss portion 21 a is supported by a bearing 22 . Further, a protection tube 24 that is attached to one end of the cylindrical outer 23 of the flexible rod portion 7b of the operating rod 7 is rotatably fitted into the housing 6, and the protection tube 24 is attached to the lock pin 2.
5, the connecting rod 27 at the end of the L inner 26 of the bendable transmission means, which is movably inserted into the cylindrical outer 23 and is prevented from coming out so as not to impede rotation, is rotated by the boss 21a of the drum 21. It is inserted integrally in the direction and movable in the axial direction. When the centrifugal clutch is engaged due to an increase in the rotational speed of the prime mover, the drum 21, its boss 21a, and the connecting rod 2
7. The inner 26 rotates to transmit power to the cutting blade, and at this time, the inner 26 and the connecting rod 27 move appropriately in the axial direction in accordance with the bending of the flexible rod portion 7b. Also,
As described above, a drum locking device 28 is provided near the drum 21 of the latch housing 6, and this device 28
A cut-and-raise 29 is provided protruding from the drum 21 side, and the cut-and-raise 2
A cylindrical body 30 is integrally formed on the top of the housing 6 at a position that coincides with the rotation locus of the lock slider 31 , and a lock slider 31 is inserted into the cylindrical body 30 so as to move and rotate toward the raised cut 29 .

The tip 31a of the lock slider 31 is notched to have a thickness that allows it to fit inside the raised cut 29 and a length that allows it to reliably engage with the raised cut 29.
An engaging pin 32 is installed vertically in the middle of the cylinder body 30, and a guide groove 33 is cut into one side of the cylinder body 30 to guide the engaging pin 32 while engaging with the engaging pin 32 at the upper part of the cylinder body 30 side. The lock slider 31
is moved in the rectangular axial direction, the tip 31a is placed inside the cut and raised 29 in a horizontal state, and then rotated 114 times to remove the tip 31a.
By standing 1a vertically, engagement with the cut and raised 29,
In other words, the rotation of the drum 21 can be locked. A handle 34 for performing such an operation is attached to the lock slider 31, and springs 35 and 36 for returning the lock slider 31 in the axial and rotational directions are biased. Further, a hook 37 is provided upright on the handle 34 of the lock slider 31.
On the other hand, as shown in FIG. 2, a hook 37 is attached to one side of the standing portion 2a on the back frame side, and another hook 38 is attached at the same height position when the lock slider is operated, and these hooks 37, 38 is adapted to engage when the lock slider 31 is operated to the lock position as described above. Since the present invention is configured in this way, the handle 34 of the drum lock device 28 is closed during non-operation such as when starting the prime mover.
The lock slider 31 is connected to the engagement pin 32 and the guide groove 33 by
When the lock slider 31 is guided and moved in the axial direction, the tip 31a of the lock slider 31 enters horizontally inside the cut and raised 29 of the clutch drum 21, regardless of its rotational phase, as shown in FIG. 9a.

Next, the lock slider 31 is placed on one side of the standing portion 2a.
After 14 rotations, the tip 31a becomes as shown in Figure b.
Even if the cut and raised 29 is located there, it is pushed away and engaged with the cut and raised 29 while standing vertically, and the drum 21
The rotation of the housing 6 is locked, and at this time the hook 37 protrudes to one side of the housing 6. On the other hand, since the prime mover 5 is rotatably supported by the backpack frame 1, along with the operation of the drum lock device 28,
Or, prior to that, while rotating the prime mover 5,
Move the clutch housing 6 closer to one side of the upright portion 2a as shown in FIG.

Then, as the prime mover 5 rotates, the fixed plate 1 integrated with it
7 is the free end 19 of the torque spring 19.
a, the spring force of the spring 19 becomes effective, and in this state the hook 37 is engaged as shown in the figure b.
, 38. As a result, the prime mover 5 is immovably fixed to the backpack frame 1 from a freely rotatable state, and at the same time, the lock slider 31 that is integrated with the hook 37 is fixedly held in the hooked position.
, 38 are maintained without coming off due to vibration, carrying of the backpack frame 1, etc. When the preparations are completed, the prime mover 5 is started by pulling the starter knob 5a. In this case, the direction in which the starter knob 5a is pulled is the direction in which the clutch housing 6 is moved away from one side of the upright portion 2a, and the hooks 37 and 38 are engaged. Coupling is prevented, and the user can concentrate on starting by simply supporting the backpack frame 1 so that it does not fall over, without having to hold down the prime mover 5.

Further, at the time of starting, if the rotational speed of the prime mover is high, the lock slider 31 of the drum locking device 28 is fixedly held in the locked position, thereby preventing the rotation of the drum 21 and causing the cutting blade 10 to
rotation is prevented. After starting the prime mover, put the prime mover 5 on your back using the backpack frame 1, grasp the handle 11 of the operating rod 7, and get into a working position. Grasp the flexible rod 7b located on the side of the operator and remove the clutch housing as shown in Figure 10c. 6 further toward one side of the standing portion 2a.

Then, the hook 37 is removed from the hook 38, and at the same time the lock slider 31 of the drum lock device 28 is released from the spring 3.
5 and 36, the drum 21 is automatically returned from the solid line to the two-dot chain line in FIG. Furthermore, when the prime mover 5 is also released from its fixation with the backpack frame 1 and becomes free, and the rotational speed of the prime mover is increased by operating the throttle lever 12, the centrifugal clutch is engaged and power is transmitted from the clutch drum 21 to the cutting blade 10. rotates, bends the flexible rod portion 7b, and swings the cutting blade 10 from side to side with the operating rod 7 while rotating the prime mover 5, thereby performing the mowing operation. As explained above, according to the present invention, the drum lock device 28 of the centrifugal crank 1 and the drum 21
The mower 5, which is rotatably mounted on the backpack frame 1, is fixed when the mower is started, so that it is possible to prevent the cutting blade 10 from accidentally rotating when the mower is started. This prevents the cutting blade 10 from moving together with the cutting blade 10 when the cutting blade 5 staggers, thereby significantly improving safety.

Maintaining the locked position of the drum lock device 28 and the prime mover 5
The two functions of fixing to the backpack frame 1 are performed simultaneously by the lock slider 31 and the hook 37 integrated with the drum lock device 28 assembled on the prime mover side. There is no problem of forgetting one operation or the operation is incomplete, and the workability is good because it can be done with one operation, and when canceling, both can be done at the same time, which simplifies the structure. Since it is fixed and held using the backpack frame 1, it has sufficient strength and reliable operation, and the rotation of the backpack frame 1, the prime mover 5 and the clutch housing 6, and the operation of the drum lock device 28 are skillfully combined. Because of this, the structure is simple and the operation can be performed smoothly and easily.

[Brief explanation of drawings]

Fig. 1 is a side view of the entire knapsack-type brush cutter showing an embodiment of the present invention, Fig. 2 is a side view of the other side of the knapsack frame and the prime mover, Fig. 3 is a plan view of the knapsack frame, and Fig. 4 5 is a plan view showing an enlarged view of the prime mover mounting portion of the backpack frame, FIG. 5 is a sectional view taken along the line ■-■ of FIG. 4, FIG. The figure is a vertical cross-sectional view of Figure 6,
The figure is a side view of FIG. 7, FIGS. 9A and 9B are explanatory diagrams of the operating state of the drum lock device, and FIGS. 10 a to c are explanatory diagrams of the operating state of the prime mover side. 1... Carrying frame, 5... Prime mover, 6.
...Clutch housing, 7...Operation rod, 7b...Flexible rod part, 10...
・Mower blade, 21...Clutch drum, 28...
... Drum lock device, 31... Field slider, 37, 38... Hook.

Claims (1)

[Claims] 1. A prime mover is rotatably mounted on a backpack frame, a clutch housing that is integrally attached to the prime mover and accommodates a centrifugal clutch is protruded to the side of the backpack frame, and one end of the flexible rod is connected to the clutch housing. In the backpack-type brush cutter, the clutch housing is provided with a drum locking device having a lock slider for locking rotation of the centrifugal clutch drum and a hook integrally attached to the lock slider, and the clutch housing is attached to the backpack frame. The hook is brought close to one side and engaged with the backpack frame, and the lock slider is held in the locked position, thereby fixing the prime mover to the backpack frame so as not to rotate, and locking the rotation of the clutch drum. A safety device for a backpack-type brush cutter, characterized in that the safety device is configured to do so.