JPH07274652A - Mower - Google Patents

Abstract

PURPOSE:To suppress noise of microvibration occurring by intermesh of a bevel gear mechanism in a mower having a reaping blade housing equipped with a bevel case and a bearing holder of a blade shaft. CONSTITUTION:A looped projected part 9 along the outer periphery of a reaping blade housing Ma is installed on the top of the reaping blade housing Ma. A bevel case B and a supporting plate 10 for a bearing holder 12 are attached to the top of the projected part 9 to form an air layer S between the top of the reaping blade housing Ma and the supporting plate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mower, and more particularly, to a mower driven from a PTO shaft on a traveling body side via a joint shaft.

[0002]

2. Description of the Related Art A conventional mower is an actual Kaihei 5-43817.
As shown in the publication, a bevel case is attached to the upper surface of a cutting blade housing via a pair of left and right support stays, and a bearing holder for a blade shaft is bolted to the back surface of the cutting blade housing.

[0003]

The vibration due to the high speed rotation of the universal joint and the slight vibration due to the occlusion of the bevel gear mechanism are transmitted to the cutting blade housing through the bevel case and the support stay, and the upper surface of the cutting blade housing causes the slight vibration. However, there is a disadvantage that resonance occurs in the cutting blade housing, and the wind noise generated by high-speed rotation of the blade mounted on the output shaft of the bevel gear mechanism penetrates the cutting blade housing, resulting in a high noise level.

Therefore, as a means for solving the above-mentioned drawbacks,
If the wall thickness of the cutting blade housing is increased to suppress fine vibrations on the upper surface of the cutting blade housing, the cutting blade housing becomes heavy.

A first object of the present invention is to suppress the noise of mower.

A second object of the present invention is to reduce the noise of the mower by reducing the weight of the cutting blade housing.

A third object of the present invention is to suppress the fine vibration of the bearing holder mounted on the cutting blade housing to further suppress the noise of the mower.

[0008]

A first characteristic configuration of the present invention for achieving the above object is to provide a loop-shaped convex portion along the outer periphery of the cutting blade housing on the upper surface of the cutting blade housing, The support plate for the bevel case and the bearing holder is attached to the upper surface of the convex portion to form an air layer between the upper surface of the cutting blade housing and the support plate.

A second characteristic structure of the present invention for achieving the above object is that the cutting blade housing is made of resin in addition to the first invention.

A third characterizing feature of the present invention for achieving the above object is to provide a bearing holder in addition to the above second invention.
The point is that the support plate is vibration-isolated and supported via an elastic body.

[0011]

According to the first characteristic configuration of the present invention, even if the support plate vibrates slightly through the bevel case and the support stay due to the high speed rotation of the universal joint or the engagement of the bevel gear mechanism, the support plate and the cutting blade Since a sound insulation layer for air is formed between the housing and the housing, resonance in the cutting blade housing due to slight vibration of the support plate is suppressed.

Further, according to the second characteristic configuration of the present invention, since the cutting blade housing is made of resin, the cutting blade housing can be reduced in weight as compared with the case where it is made of an iron plate. The noise damping effect is high, and the sliding contact noise of grass clippings can be kept low.

Further, according to the third characteristic configuration of the present invention,
Since the bearing holder is vibration-isolated and supported by the support plate via the elastic body, the microvibration of the blade shaft that also serves as the output shaft generated by the engagement of the bevel gear mechanism is transmitted to the cutting blade housing through the holder. Can be suppressed.

[0014]

As described above, according to the first characteristic configuration of the present invention, noise generated due to the occlusion of the bevel gear mechanism is suppressed, and a quiet mowing operation in a residential area becomes possible.

Further, according to the second characteristic configuration of the present invention, the noise level can be further suppressed.

Further, according to the third characteristic configuration of the present invention,
The fine vibration of the support plate is suppressed, and the noise level is further suppressed.

[0017]

Embodiments of the present invention will be described below with reference to a mid-mount type riding lawn mower in which a mower is mounted between front and rear wheels.

As shown in FIG. 1, a mower M is movably connected between front and rear wheels 1 and 2 of a traveling body A via a link mechanism R, and a mid PTO projecting from a mission case 3 is connected.
Power is transmitted from the shaft 4 to a bevel gear mechanism installed in the bevel case B on the upper surface of the cutting blade housing Ma through a transmission shaft 5 having a universal joint.

As shown in FIG. 2, the mower M is a three-blade type mower in which three blades Mb are housed in a resin cutting blade housing Ma and also serves as an output shaft of the bevel gear mechanism 6. The belt 8 is wound around the output pulley 7A mounted on the center blade shaft 7a and the pulleys 7B, 7B mounted on the blade shafts 7b, 7b on both sides, so that the blade shafts 7b, 7b on both sides are separated from the center blade shaft 7a. Is designed to drive.

As shown in FIG. 3, the cutting blade housing M
A loop-shaped convex portion 9 is integrally formed on the upper surface of a along the outer periphery of the cutting blade housing Ma, and a support plate 10 made of sheet metal is bolted to the upper surface of the convex portion 9.

As shown in FIGS. 2 and 3, the bevel case B is fixedly connected to the support plate 10 via a pair of left and right support stays 11, 11 and the center blade shaft 7a is rotatable. The bearing holder 12 for supporting the blade shafts 7b, 7b on both sides and the bearing holder (not shown) for rotatably supporting the blade shafts 7b, 7b are fixedly connected.

The bearing holder 12 is vibration-supported with respect to the support plate 10 via a vibration-proof rubber 13 as an elastic body.

As shown in FIG. 4, the anti-vibration rubber 13 is
The outer collar 13a has a structure in which a rubber 13c is baked and fixed between the outer collar 13a and the inner collar 13b. The outer diameter of the outer collar 13a is substantially the same as the inner diameter of the fitting hole 12a formed in the bearing holder 12, or ,
The diameter is slightly larger than that, and the inner diameter of the inner collar 13b is formed to be the same or substantially the same as the outer diameter of the fixing bolt 14.

With the above structure, a sound insulation layer of the air layer S is formed between the upper surface of the cutting blade housing Ma and the support plate 10.

A resin cover 15 is provided above the support plate 10 for covering the belt transmission device such as the belt 8 and the pulleys 7B, 7B.
And is connected together with the support plate 10 together.

[Other Embodiments] The cutting blade housing Ma is
It may be made of a thin iron plate made of sheet metal.

In the above embodiment, the bevel case B and the bearing holder 12 are previously attached to the support plate 10.
The cutting blade housing M has been assembled by assembling the cutting blade housing Ma with the cutting blade housing Ma.
The support plate 10 may be assembled to the a first, and then the bevel case B and the bearing holder 12 may be assembled.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

1] Overall side view

FIG. 2 is a plan view of mower.

[Fig. 3] Vertical side view of mower

FIG. 4 is a vertical sectional view showing a vibration-proof support structure of a bevel case.

[Explanation of symbols]

 9 Convex part 10 Support plate 12 Bearing holder 13 Elastic body B Bevel case Ma Cutting blade housing S Air layer

Claims (3)

[Claims] 1. A mower in which a bevel case (B) and a bearing holder (12) for a blade shaft are mounted on a cutting blade housing (Ma), the cutting blade housing (Ma).
Is provided with a loop-shaped convex portion (9) along the outer periphery of the cutting blade housing (Ma), and the bevel case (B) and the bearing holder (1) are provided on the upper surface of the convex portion (9).
A mower having a support plate (10) attached to (2) to form an air layer (S) between the upper surface of the cutting blade housing (Ma) and the support plate (10). 2. The mower according to claim 1, wherein the cutting blade housing (Ma) is made of resin. 3. The mower according to claim 1, wherein the bearing holder (12) is vibration-damped to the support plate (10) via an elastic body (13).