JPS61187716A - Reaper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a pruning machine for pruning branches.

[Background technology]

Conventionally, in a mowing machine blade in which a comb-shaped movable blade reciprocates on a comb-shaped fixed blade, as shown in FIG.
When cutting, a component force F of the force F is applied to the inclined surface of the cutting edge portion 31 of the movable blade 31, and the movable blade 31 is pushed down toward the fixed blade 30, so that the movable blade 31 and the fixed blade 30 are
As a result, the movable blade 31 and the fixed blade 30 have δ0. Cutting edge wear step of δ2 δ0. There was a problem that δ2 occurred. As a result, the sharpness of the branches 32 deteriorates, resulting in a short cutting life.

[Purpose of the invention]

The purpose of this invention is to eliminate the difference in edge wear between a movable blade and a fixed blade due to edge interference, and to maintain a sharp edge at all times to extend the cutting life.

[Disclosure of the invention]

The mowing machine of the present invention includes a comb-shaped fixed blade and a comb-shaped movable blade that slides on the fixed blade, and a ceramic layer is formed on the sliding surface of either the fixed blade or the movable blade, The other sliding contact surface is formed of tool steel, and the tool steel (cutler steel>f
: The hardness decreases as the distance from the cutting edge increases compared to the cutting edge.

According to this configuration, one of the sliding contact surfaces of the fixed blade and the movable blade is made of a ceramic layer and the other is made of tool steel, so that the blade with the hard ceramic layer does not suffer much wear. A wear level difference occurs on a cutting edge made of tool steel due to interference between the cutting edges, but since the part of the sliding contact surface of a tool steel blade away from the cutting edge is softer than the cutting edge, the sliding contact with the hard Ceramic layer is softer than the cutting edge. It can be easily polished by contacting the blade, and there is no difference in the level of wear on the cutting edge. By repeating this action, the sliding surface of the tool steel blade is constantly ground to a flat surface, maintaining the sharpness of the cutting edge and extending its cutting life.

Embodiment An embodiment of the present invention is shown in FIGS. 1 to 4. FIG. 3 shows the entire mowing machine, and FIG. 4 is an enlarged view of its blade. In the figure, 1 is a comb-shaped fixed blade, on which a comb-shaped movable blade 2 is provided so as to be slidable in the longitudinal direction (in the direction of arrow Q), and a blade cover 3 is further placed thereon.

The movable blade 2 is reciprocated and linearly driven by a motor provided in the main body 4 via a rotational and linear motion conversion mechanism.

The movable blade 2 is held down by a pressing spring 5 K as shown in FIG.

FIG. 1 shows a cross section of the comb tooth portions of the fixed blade 1 and the movable blade 2. A ceramic layer 6 is provided on the sliding surface 1m of the fixed blade 1. This ceramic layer 6 has A I , 8 i
, Cr, Zr, W, Ti, etc. oxide, carbide, or titanium material (hardness H71
000 or more)-1', coated with a thickness of 20 μm or less by a method such as thermal spraying, PVD method, CVD method, or tipping. Accordingly, the cutting edge portion 1b of the fixed blade l is also coated with the ceramic layer 6.

The movable blade 2 is made of tool steel (knife steel), and its sliding surface 1
As shown in the hardness distribution diagram of FIG. 1, the hardness of the blade 1 is such that the hardness decreases continuously as the distance from the cutting edge portion 1a increases. The 9th point shown in the movable blade 2 in FIG. 1 represents the high hardness part a at the hardness K and the low hardness part bt. This hardness distribution is formed by the hardening treatment and carburizing treatment.

According to the S configuration with the operation, the sliding surface 1a of the fixed blade 1 is made of a hard ceramic layer 6, and the sliding surface 2& of the movable blade 2 is made of tool steel. Also in the portion 1b, no wear occurs.

The movable blade 2 causes the blade edge portion 2b to have a shape as shown in Fig. 2 (2) due to blade edge interference.
), a wear step 8 occurs, but the sliding surface 2 of the movable blade 2
Since the portion of the blade away from the cutting edge portion 2b is softer than the cutting edge portion 2b, it is easily polished by sliding contact with the hard ceramic layer 6, and the cutting edge wear step 8 is eliminated. The shaded portion 9 in FIG. 2 indicates this portion to be polished. By repeating this action, the sliding surface 2m of the movable blade 2 is constantly polished to a flat surface, and the sharpness of the cutting edge 2b is maintained at 1. By using the fixed blade 1 that does not wear out, the blade has a long cutting life. can.

5 to 8 show a second embodiment. This example:
A sink portion 10 is formed on the sliding surface 2a/ of the movable blade 2',
And the sliding surface 21' is the same as the cutting edge part 2 b' and the sink part 1
The 0 side is an inclined surface that gradually recedes into a straight line. This slope is formed by pressing or polishing. In this case, as in the first embodiment, the fixed blade IK ceramic layer 6 is provided, and the movable blade 2' is made of tool steel whose hardness is continuously changed (hardness H, 650). Other configurations are
First 5j! It is the same as the example.

When formed in this way, since the sliding contact area between the fixed blade 1 and the movable blade 2' is small, the sliding load is smaller compared to the first embodiment, and the polishing effect of the movable blade 2' is increased. An even sharper state can be obtained. FIG. 6 shows the state of polishing, and the cutting edge step 8 of the movable blade 2' is polished into a flat surface as shown in FIG. FIG. 8 shows a state in which polishing is repeated. 11
12 is a worn part due to interference of the cutting edge, and 12 is a polished part by the fixed blade 1.

FIG. 9 shows a third embodiment. In this example, the sliding surfaces 2 and II of the movable blade 2# are only in the vicinity of the cutting edge part 2b', and the part away from the cutting edge part 2b' is shaped like a staircase to the sink part lo side. , a is a high hardness portion, C is a medium hardness portion, and b is a low hardness portion. In this case as well, the same effects as in the 20th embodiment can be obtained.

FIG. 10 shows a fourth embodiment. In this example, the movable blade 20
It is made of three layers of cladding material. The outer layer 20A is 1~
The intermediate layer 20B has a carbon content of 1.5%, the intermediate layer 20B has a carbon content of 0.3 to 0.8%, and the inner layer 200 has a carbon content of 0.2% or less. In this case as well, the same effects as in the first embodiment can be obtained.

In the above embodiment, the fixed blade IK ceramic layer 6 is provided, but the movable blades 2 to 2' may be provided with a ceramic layer, and the fixed blade 1t may be made of tool steel having a different hardness.

〔Effect of the invention〕

The mower of the present invention eliminates the difference in the wear of the movable blade and the fixed blade due to interference between the blade edges, and maintains the blade edge sharp at all times.
This has the effect of extending the cutting life.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the cross section and hardness distribution of the blade portion of an embodiment of the present invention, FIG. 2 is an explanatory diagram of its operation, FIG. 3 is a perspective view of the entire blade, and FIG. FIG. 5 is a sectional view of the blade of the second embodiment, FIG. 6 is an explanatory diagram of its operation, FIG. 7 is an explanatory diagram of its polished state, and FIG. 8 is its cutting edge. FIG. 9 is a cross-sectional view of the blade portion of the third embodiment. FIG. 10 is an explanatory diagram of the cross-section and hardness distribution of the blade portion of the fourth example.
The figure is an explanatory diagram of the operation of a conventional example, and FIG. 12 is a cross-sectional view of the blade portion showing the wear of the cutting edge. 1...Fixed blade, 2, 2', 2'-...Movable blade, 2
m, 2m'. 2 m"" sliding surface, 2 b, 2 b', 2 b'
-...Blade tip, 6...Ceramic layer Fig. 4, Fig. 5, Fig. 6, 11 12 2a □7, Fig. 8

Claims (6)

[Claims] (1) Equipped with a comb-shaped fixed blade and a comb-shaped movable blade that slides into contact with the fixed blade, a ceramic layer is formed on the sliding contact surface of either the fixed blade or the movable blade, and the sliding contact surface of the other A mowing machine whose surface is formed of tool steel, and the tool steel has a hardness that decreases as the distance from the cutting edge increases compared to the cutting edge. (2) The mowing machine according to claim (1), wherein the tool steel has a continuously low hardness. (3) The mowing machine according to claim (1), wherein the tool steel has a lower hardness in stages. (4) The mowing machine according to claim (2), wherein the tool steel is continuously made to have a low hardness by nitriding. (5) The mowing machine according to claim (2), in which the tool steel is continuously made to have a low hardness by carburizing. (6) The mowing machine according to claim (3), wherein the tool steel has a stepwise lower hardness using three layers of cladding material.