JPH0367519A - Hydraulic driving type bush cutter - Google Patents

Abstract

PURPOSE:To carry out bush cutting operation with excellent operating efficiency by rotating and driving cutting blades with turbine blades rotatable under a hydraulic pressure with a hydraulic pump driven by a prime mover. CONSTITUTION:An oil feeding pipe (3b) and an oil return pipe (4b) of a hydraulic pump additionally provided in a prime mover are inserted and passed through an operating lever 5 to rotate turbine blades 7 under a hydraulic pressure and drive cutting blades 8. Vibration of the operating lever 5 due to vibration of the prime mover or hydraulic pump cab be eliminated to perform bush cutting operation by holding the operating lever with excellent operating efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a hydraulically driven brush cutter whose cutting blades can be rotationally driven by hydraulic pressure.

[Prior Art] In a conventional brush cutter of this type, a transmission shaft driven by an internal combustion engine or an electric motor is inserted into an operating rod, and the cutting blade is attached to a gear case connected to the tip of the operating rod. The structure is such that the transmission shaft is transmission-coupled and the cutting blade is mechanically driven to rotate.

[Problem to be solved by the invention] In such a conventional structure, a long transmission shaft must be supported at several locations inside a long operating rod, making machining and attaching difficult, resulting in increased costs. However, due to the generation of vibration and noise, operability was poor, and the mechanical transmission structure required a large number of parts, resulting in frequent mechanical loss.

[Means for Solving the Problems] The present invention solves such problems and makes it possible to perform brush cutting work with good operability. An oil feed pipe and an oil return pipe extending from the pump are inserted into an operating rod, and a cutting blade driven by a built-in turbine blade is mounted on a shaft in a case connected to the tip side of the operating rod. and an oil return pipe are connected to the outer periphery of the turbine blade so that the cutting blade can be rotationally driven by hydraulic pressure.

[Function] Therefore, the mower blade can be rotated without rotating the turbine blades by the hydraulic pressure from the hydraulic pump driven by the prime mover, and mowing work can be performed with good operability by holding the operating rod that does not vibrate. You will be able to do that.

[Example] Next, the example shown in the drawings will be described.〇 Figure 1 shows a side view of the entire hydraulically driven brush cutter, and shows a backpack frame ( 14〉A prime mover (1) and a hydraulic pump (2) directly connected and driven by the prime mover (1) are mounted on the top, and a switching valve box is connected to the rear end of a long round pipe operating rod (5). (10a) and the hydraulic pump (2) is connected with a flexible oil pipe (
3a) and the oil return pipe (4a) are connected to each other,
Inside the case (6) connected to the front end of the operating rod (5) is a rotating shaft (5) having a turbine blade (7) on the upper part.
), and a cutting blade (0) covered with a safety cover (16) is fixedly mounted on the lower end of the rotary shaft (15), and an oil pipe extending from the switching valve box (10a) is attached. (3b)
and Ab return pipe (4a) are pushed through the inside of the operating rod (5) to the tip, and both pipes (3b) (4b
) are connected to the outer periphery of the turbine blade (7), so that the cutting blade 0) can be rotationally driven without rotating the turbine blade (7) by hydraulic pressure.

Furthermore, a rubber grip (17) that can be held with one hand is fitted at the rear of the operating rod (5), and a handle (1g) that can be held with the other hand is fitted on the front side of the rubber grip (17). is fixedly installed, and the grille 1. A throttle lever (11) that can be operated with one hand holding the grip (17) is pivoted on a fulcrum m (20) at the rear of the latch (19) which is suspended in front of the grip (17) by a fixing band (19a). A throw wire (22) consisting of an inner (lea) and an outer (22b) with a spring (20) interposed therein extends from the front arm (lla) of the throttle lever (1) into the latch (19). is linked to the throttle of the prime mover (1), and the mower (14) is connected to the throttle of the prime mover (1), so that the mowing work can be carried out by carrying the carrying frame (14) on one's back.

In addition, (17a) shows a rubber damper part provided on the grip (17), and when the throttle lever (II) is squeezed harder than the state in which it is in contact with this, the rubber damper part (17a) deforms and the throttle lever Adjustment <-(11)
The inner wire (33a) of the brake Bowden wire (33) can be pulled and operated by rotating.

At the rear of the upper part of the switching valve box (10th>), two parallel oil passages (23a) and (24a) are formed in the front and rear direction, which communicate with the oil sending pipe (3a) and the oil return pipe (4a), and at the front. are parallel oil passages in the front and back direction that communicate with the oil sending pipe (3b) and the oil return pipe (4b)
23b) (24b) and an O-ring (25
) (25) is fitted into the switching valve box (10a), and the oil passage (25) is fitted in the upper part of the switching valve (10).
3a) Both parallel oil passages (26a) in the front and rear direction that can match (23b) and (24a) (24b), respectively.
(26b) and the switching valve (10) on the lower side thereof.
A lateral oil passage (9a) is formed in the front part of the oil passage (23b) (!4b) with both ends thereof communicating with each other and having a narrow passage (0) in the middle part, and a switching valve which is the rear part thereof. At the rear of (10), a lateral simplification (27) is formed to communicate with both the oil passages (!3a) (Ha) at both ends.

Further, a compression spring (28) is fitted below the switching valve (10) between the inner bottom of the switching valve box (10a) and the switching valve 00), and an upper end is fitted on the outer periphery of the switching valve (10). (29a) forms an engagement groove (2g) in the vertical direction that is slightly narrower and deeper, and an engagement groove (2g) that is pressed toward the engagement groove (29) by a spring (30) is formed on the outer periphery of the switching valve box (lea). A spring (32) with a weaker spring force than the throttle wire spring (21) is fitted with a pin (31) and extends from the lower end side of the front arm (Ila) of the throttle lever (If) into the latch (19). ) interposed inner (33a) and outer (33b)
The other end of the Bowden wire (33) is interlocked with the outer end of the engaging pin (3), but the throttle can be adjusted by slightly moving the throttle lever (11) up and down. (17) rubber damper (17)
When a) is moved up a lot so that it deforms, the engagement pin (
31) is installed and configured so that it can be operated.

Then, while carrying the prime mover (1) etc. on your back, hold the grinding knob (17) with one hand, hold the handle (18) with the other hand, and operate the operating rod (5) while working to cut the grass. 5 and 6.
As shown in the figure, the tip of the engagement pin (31) engages pt (
If you push down the switching valve (10) until it fits and locks into the upper end part 09a) of 29), the slot, Fl-le lever (
By operating the hydraulic pump (2) while adjusting the rotation speed of the prime mover (1) using 11), the turbine blades (7>) are driven by hydraulic pressure while oil flows as shown by the arrows in Figures 5 and 6. By rotating it, the cutting blade (8) can be rotationally driven, and the oil will be returned to the hydraulic pump (jl).

To stop the cutting blade (0), press the throttle lever (1
1) in the direction of arrow (A), the engagement pin (31) is pulled by the operation of the Bowden wire (33), and the switching valve (10) is pulled up as shown in FIGS. 7 and 8. ) will move upward, and the oil from the hydraulic pump (2) will flow back through the oil passage (27) without any hindrance, as shown by the arrows in Figures 7 and 8. Therefore, the flow of oil flowing back from the turbine blade (7) rotating due to inertia is regulated when passing through the narrow passage 0), making it possible to effectively brake the turbine blade (1). This makes it possible to quickly, safely and easily stop the cutting blade (6) without stopping the hydraulic pump (2).

In addition, as another embodiment, the switching valve box (lea) and the switching valve (10) are removed, and the oil pipe (3a) of the above embodiment is replaced.
, (3b) and the oil return pipes (4a), (4b) may be constructed into an oil sending pipe and an oil return pipe, respectively.

Furthermore, remove the hydraulic pump (2) directly connected to the prime mover a (1) from the backpack frame 00, and install the prime mover (1) as in the conventional model.
Alternatively, fix one end of the operating rod (5) to the hydraulic pump (2) that is directly connected to the prime mover (1), extend a hanging bracket from the hydraulic pump (2)*, and allow the worker to hang it with a hanging band. Even if configured to lower the amount, the objects and effects of the present invention can be achieved.

[Effects of the Invention] As described above, the present invention provides the turbine blades (7) with extraction pressure from the hydraulic pump (2) driven by the prime mover (1).
The cutting blade (8) can be efficiently rotated without having to rotate the blade (8), and the operating rod (5) can be held comfortably and mowing work can be performed with good operability without generating vibration or noise unlike the conventional type. This makes it possible to make the aircraft structure more compact and easier to manufacture than the conventional type, and has the advantage of being suitable for implementation.

[Brief explanation of drawings]

Fig. 1 is a side view of a hydraulically driven brush cutter as an example;
3 is a plan view of a portion of FIG. 1, FIG. 4 is a sectional view of a portion of FIG. 1, 5vJ is a side sectional view of the switching valve section, 6 is a plan sectional view of a part thereof, FIGS. 7 and 8 are explanatory views of the operation of FIGS. 5 and 6, respectively, and FIGS. 9 and 10 are IX-IX of FIG. 8.
FIG. 3 shows a side view of a portion of the switching valve seen from the line and the line X-X, respectively. -(1)...Motor (2)...Hydraulic pump (3a) (3b)...Oil pipe

Claims (1)

[Claims] An oil feed pipe and an oil return pipe extending from a hydraulic pump attached to the prime mover are inserted into an operating rod, and a cutting blade driven by a built-in turbine blade is mounted on a shaft in a case connected to the tip side of the operating rod. A hydraulically driven brush cutter characterized in that the oil sending pipe and the oil return pipe are connected to the outer periphery of the turbine blade so that the cutting blade can be rotationally driven by hydraulic pressure.