JPS6038339Y2 - Flexible rod attachment device for backpack-type brush cutters - Google Patents

Description

[Detailed description of the invention] This invention is equipped with a flexible rod part as an operating rod in part or all of the power transmission system of the prime mover mounted on the backpack frame from the cutting blade at the tip, and the rotational power of the prime mover is transferred to the cutting blade. The present invention relates to an attachment device for attaching the flexible rod portion to the cutting blade side and the clutch housing in a backpack-type brush cutter in which the cutting blade is operated by swinging the cutting blade from side to side to cut the grass.

A backpack-type brush cutter has been proposed in which a prime mover is mounted on a backpack frame, and the prime mover is carried on the back using the backpack frame.

In such a backpack-type brush cutter, since the prime mover is located behind the worker, the operating lever operated in front of the worker bypasses the side of the worker and is connected to the prime mover.

Therefore, at least the portion of the operating rod that bypasses the side of the operator needs to be a flexible rod portion.

By the way, the flexible rod portion is made up of a flexible cylindrical outer member and an inner member made of a tightly spirally wound wire inserted into the inner member so as to be movable in the axial direction.

Since the cylindrical outer is flexible, it is difficult to attach both ends thereof to the cutting blade side member and the clutch housing as they are.

Therefore, it is conceivable to fit protective tubes around the outer periphery of both ends of the cylindrical outer, respectively, and attach the cylindrical outer through the protective tubes.

However, if the protective tube is plastically deformed from the outer circumferential side and the protective tube and the cylindrical outer are caulked and fixed, when the flexible rod portion is bent, such as when using a brush cutter, it may come into contact with the opposite end of the protective tube of the cylindrical outer. There is a problem in that large bending stress acts locally on the portion, causing damage to the abutting portion of the cylindrical outer, premature aging, and cracking, particularly in the caulked and fixed portion.

The present invention solves the above-mentioned problem by forming a tapered enlarged diameter part at the opposite end of the protective tube, so that the opposite end has a larger diameter, and the protective tube and the cylindrical outer are caulked and fixed. Even though
The object of the present invention is to provide a flexible rod attachment device for a backpack-type brush cutter that does not cause damage to the caulking fixing portion of the cylindrical outer or premature aging of the contact portion with the expanded diameter portion of the protective tube. .

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

First, the overall outline of the backpack-type brush cutter will be explained with reference to FIGS. 1 to 3.

Reference numeral 1 designates a frame for carrying on the back, and a back support 3 and a band 4 are attached to an upright portion 2a of the frame 2, which has an oval shape when viewed from the side, and is worn on the back.

Also, a stand 6 is mounted on the horizontal part 2b of the frame 2 via a rubber cushion 5 for vibration isolation, and a fixing plate 8 of the prime mover 7 is supported by bearings on the stand 6, so that the prime mover 7 can be rotated horizontally. A clutch housing 9 containing a centrifugal clutch is attached to the prime mover 7, and this housing 9 protrudes to the side of the frame 1 on the back.

Reference numeral 10 denotes an operation frame, which includes an elongated metallic rigid rod portion 1.
0a and the flexible rod portion 10b, these rod portions 10a and 10b are connected by a holder 11 or the like, and further connected to a portion of the clutch housing 9 on the proximal end side of the flexible rod portion 10b.

A cutting blade 13 is attached to the tip of the rigid rod portion 10a together with a gear case 12, a handle 14 is attached to an appropriate location, a throttle lever 16 is attached to a grip 15 adjacent to the holder 11, and the cutting blade 13 is attached to an operating lever. The throttle lever 16 is connected to the prime mover 7 through a transmission system (described later) in the engine 10 so as to be driven by its rotational power, and the throttle lever 16 is similarly connected to the prime mover 7 by a throttle wire 17 shown in FIG. 4a.

The operating rod 10 will be described in detail with reference to FIGS. 4a and 4b.

The rigid rod portion 10a is formed by inserting a transmission shaft 19 into a metal cylinder 18, and a snap ring 1 is attached to the end of the cylinder 18.
The holder 11 is secured to the holder 11 by 8a, and a bearing 22 is assembled into the holder 11 by a bearing holder 20 and a spacer 21.

A slip joint 23 is installed inside this bearing 22.
are integrally attached, and the transmission shaft 19 is screwed onto one side of the joint 23 to be pivotally supported.

In the flexible rod part 10b, an inner 25, which is configured by tightly winding a wire rod inside a flexible cylindrical outer 24 and capable of transmission and bending, is inserted into the cylindrical outer 24 axially and rotatably. be.

The cylindrical outer 24 is provided with a flexible liner 24a1 felt (including one in which thin mesh wire mesh is wound 2 to 5 times) 24b and a flexible covering 24c in this order from the inner circumferential side to the outer circumferential side. It has a three-layer structure.

A metallic protective tube 26a is provided on the outer periphery of both ends of the cylindrical outer 24.
, 26b are fitted, respectively, and both protection tubes 26a, 26b
Tapered enlarged diameter portions 26a1 and 26b1 are formed at the opposing ends of the tapered diameter portions 26a1 and 26b1, respectively.
a, , 26b, at positions closer to both ends of the cylindrical outer 24, axially as far as possible from each other.
By applying force from the outer circumferential side of these to form a plurality of plastically deformed portions 26a2, 26b2 in the circumferential direction, the protective tubes 26a, 26b are caulked and fixed to the cylindrical outer 24, and the protective tubes 26a, 26b are The opposing end and the opposite end protrude from both ends of the cylindrical outer 24 in the axial direction.

Furthermore, connecting rods 27a and 27b each having a rectangular tip are attached to both ends of the inner 25 of the flexible rod portion 10b.

The protective tube 26a at one end of the cylindrical outer 24 is connected to the holder 11.
The connecting rod 27a at one end of the inner 25 is inserted into the other slip joint 23 so as to be integral with the slip joint 23 and movable in the axial direction.

On the other hand, a clutch drum 28 of a centrifugal clutch is housed in the clutch housing 9 on the side of the prime mover 7.
8 bosses 29 are supported by bearings 30.

Then, the protection tube 26b at the other end of the cylindrical outer 24 is fitted into the clutch housing 9, and the tip of the connecting rod 27b at the other end of the inner 25 moves axially integrally with the boss 29 of the clutch drum 28 in the rotational direction. When the rotational speed of the prime mover 7 reaches a predetermined value and power is taken out to the clutch drum 28, this power is transferred to the boss 29, the connecting rod 27b1, the inner 25 of the flexible rod portion 10b, and the connecting rod 27b. It is transmitted to the cutting blade 13 side via the rod 27a1 slip joint 23 and the transmission shaft 19, and at this time, the flexible rod portion 1
Inner 25 and connecting rods 27a, 27 according to the bending of 0b.
b moves in the axial direction.

Here, the flexible rod part 10b cannot completely absorb the twisting that occurs when the handle 14 of the rigid rod part 10a is used to turn the rigid rod part 10a and the cutting blade 13 is tilted to perform mowing operations. In view of this, the flexible rod portion 10b
Protective cylinders 26a and 26b at both ends of the holder 11 are rotatably fitted to the spacer 21 of the holder 11 and the clutch housing 9.

Further, an attachment/detachment mechanism A is provided on the clutch housing side of the flexible rod portion 10b, so that the operating rod 10 can be attached to and removed from the prime mover 7.

This mechanism A will be described in detail with reference to FIGS. 4a and 4b and FIGS. 5 to 9.

A groove 31 having a semicircular cross section is formed in an annular shape on the outer periphery of the clutch housing side protection tube 26b of the flexible rod portion 10b.

On the other hand, holes 32 are drilled in the housing 9 in the tangential direction at locations that coincide with the grooves 31, and pins 33 are provided in these holes 32 and a portion of the grooves 31 to prevent the protection tube 26b from coming out without interfering with its rotation. Insert it like so.

Then, the part of the pin 33 that matches the groove 31 is cut out in a half-moon shape, and the half-moon part 33a is made vertical as shown in FIG. Rotate 90 degrees so that the half moon part 33a
By locating only in the hole 32, the protection tube 26
The engagement with b is disengaged.

A knob 34 is attached to one end of the pin 33, and a flange 33b at the other end is biased by a spring 35.

The knob 34 is pressed by the spring 35 against a guide protrusion 36 using the side part of the housing, and the guide protrusion 36 is attached to the pin 36 as shown in FIGS. 7 to 9.
The knob 34 along with the half-moon part 33a of 3 has low flat surfaces 36a and 36b located vertically and horizontally, and these flat surfaces 3
A slightly higher flat surface 36e is connected to the 90 degree rotation range of the knob 34 between 6a and 36b via tapers 36C and 36d, and further positions the knob 34 on each of the flat surfaces 36a and 36b and regulates the operating direction. There is a stopper 36f that prevents the knob 34 from rotating in the opposite direction.The knob 34 is held on the flat surfaces 36a, 36b at each position, and the spring 35 presses the knob 34 against the flat surfaces 36a, 36b. 33 is designed to prevent it from rotating inadvertently.

On the other hand, the cutting blade side, that is, the holder side of the flexible rod portion 10b is assembled integrally, and this is shown in Fig. 4a.
This will be explained with reference to FIG.

A groove 37 is formed in the holder-side protection tube 26a of the flexible rod portion 10b, similar to the clutch housing side.

A hole 38 is bored in the tangential direction of the spacer 21 and the holder 11 at a location that coincides with this groove 37.
By passing the bolt 39 through B and a part of the groove 37, the protective cylinder 26a is prevented from coming off without interfering with its rotation.

Furthermore, a stopper 40 is attached to the connecting rod 27b within the protection tube 26b at one end of the flexible rod portion 10b, for example.
It is attached so as to hit the inner protrusion 26c at the tip of the protection tube 26b and the inner bulge 31a of the groove 31 to prevent the inner 25 from coming off both in the front and rear.

In this embodiment, the protection tubes 26a and 26b have the same configuration so that they can be used in common, thereby making it easier to manufacture and manage the protection tubes.

Since the device of this embodiment is configured as described above,
Turn the knob of the attachment/detachment mechanism A clockwise while pulling it out against the spring 35, and then turn the knob 34 into the taper 36c.
through the plane 36e, and then the taper 36d
The knob 34 is held horizontally at this position by being regulated by a stopper 36f, and at this time, the half-moon part 33a of the pin 33 is placed only in the upper hole 32 as shown in FIG. To position.

Therefore, the protective tube 26b at one end of the flexible rod portion 10b becomes free, and by detaching from the clutch housing 9, the operating rod 10 is separated from the prime mover 7 and packed.
It can be conveniently transported, and at this time, the inner 25 of the flexible rod portion 10b is held in the cylindrical outer 24 by the stopper 40 to prevent it from coming out.

Next, during grass cutting work, the protective tube 26b at one end of the flexible rod portion 10b is inserted into the clutch housing 9 at the site.
Turn the knob 34 of the attachment/detachment mechanism A so that it becomes perpendicular through the tapers 36c, 36d and the plane 36e, and
Spring 35 is connected between taper 36b and stopper 36f at point a.
When the pin 33 is positioned and held, the half-moon part 33a of the pin 33 is located across the groove 31 and the hole 32 as shown in FIG.
As a result, the operating rod 10 is assembled to the prime mover 7 side.

After that, start the prime mover 7, carry the prime mover 7 on your back using the backpack frame 1, hold the operating rod 10 with the handle 14, and increase the rotation speed of the prime mover 7 with the throttle lever 16.
Inner 25 of flexible rod portion 10b, rigid rod portion 10a
The cutting blade 13 is rotationally driven by power transmission through a transmission shaft 19 or the like.

Therefore, when the cutting blade 13 is swung left and right, the flexible rod portion 10
b is bent appropriately and the prime mover 7 is rotated to perform the mowing work in a predetermined range, and only the rigid rod portion 10a is cut by the holder 11 at the joint with the flexible rod portion 10b, or both rod portions 10a and 10b are combined. In other words, by turning the clutch housing 9, it is possible to perform work with the cutting blade 13 tilted.

In addition, in the present invention, the means for attaching the protective tube of the flexible rod portion to the clutch housing and the member on the cutting blade side are as follows:
Although it does not necessarily have to be done as in the above-mentioned embodiment, if it is done as in the embodiment, the flexible rod can be easily and reliably attached to and detached from the clutch housing by a knob operation. Holder 1 of the above embodiment
One protection tube of the cylindrical outer may be attached to a member other than 1 on the cutting blade side.

As explained above, according to the present invention, the flexible rod attachment device for a backpack-type brush cutter is provided by fitting protective tubes around the outer periphery of both ends of the flexible cylindrical outer of the flexible rod. Forming a tapered enlarged diameter portion at the opposite end of the cylinder, the diameter of which becomes larger on the opposite end side,
Both protective tubes are plastically deformed from the outer circumferential side at a position axially apart from the enlarged diameter portion, and the protective tube and the cylindrical outer are fixed by caulking, so that the protective tube and the cylindrical outer can be easily caulked. Although it can be fixed during work, when the flexible rod part bends when using a brush cutter, the cylindrical outer part will bend due to a larger radius than when the protective cylinder does not have the expanded diameter part described above. , without applying large bending stress locally to the cylindrical outer, and by dispersing the stress, the portion of the cylindrical outer corresponding to the enlarged diameter part may be damaged, or repeated bending angle changes may occur. Early aging can be prevented, and in particular, since the cylindrical outer is caulked and fixed from the outer circumferential side of the protective tube at a position apart from the expanded diameter section, the caulked and fixed part of the cylindrical outer is not elastically deformed. Also, unreasonable force due to bending of the cylindrical outer is not applied to these parts, and therefore cracks can be prevented from forming in the portion of the crimped fixing part of the cylindrical outer on the side opposite to the protective cylinder. This has the effect of maintaining the state in which the and the cylindrical outer are firmly caulked and fixed for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a side view of one side of the entire backpack-type bush cutter showing an embodiment of the present invention, Fig. 2 is a side view of the other side of the frame and the motor portion on the backpack, and Fig. 3 is a plan view of the frame on the backpack. Fig. 4a is an enlarged sectional view of the main part of the present invention, Fig. 4 is an enlarged side view with a part of the fixing part between the cylindrical outer and the protective tube cut away, Figs. 5 and 6
The figures are the XX cross-sectional view and the Y-Y cross-sectional view of Figure 4a, Figure 7 is the view from the arrow in Figure 6, and Figures 8 and 9 are the cross-sectional view from the arrow in Figure 7. The arrow view, FIG. 10 is the Z-Z sectional view of FIG.
FIG. 1 is an explanatory diagram of the operating state. 1... Frame on the back, 7... Prime mover, 9.
...Clutch housing, 10...Operation rod, 10a...Rigid rod portion, 10b...
Flexible rod portion, 11... Holder (member on the cutting blade side), 24... Cylindrical outer, 25...
・Inner, 26a, 26b...Protective tube, 26a
1,26b1... Expanded diameter part, 26a29 26b
2...Plastic deformation part.

Claims (1)

[Scope of utility model registration request] A prime mover having a clutch housing is rotatably mounted on a backpack frame, and consists of an inner that transmits power from the prime mover to the cutting blade side, and a cylindrical outer that attaches both ends to the clutch housing and the cutting blade side member. In a backpack-type brush cutter equipped with a flexible rod, protective tubes are fitted to the outer peripheries of both ends of the flexible cylindrical outer of the flexible rod, and the opposite end side is fitted to the opposite ends of both protective tubes. A tapered expanded diameter portion having a large diameter is formed respectively, and both protective tubes are plastically deformed from the outer circumferential side at a position spaced apart from the expanded diameter portion in the axial direction, so that the protective tube and the cylindrical outer are connected to each other. A flexible rod attachment device for a backpack-type brush cutter, characterized in that the rod is fixed by caulking, one protective tube is attached to a mower blade side member, and the other protective tube is attached to a clutch housing.