JPH073868Y2 - Cutting blade clutch structure in lawn mower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cutting blade clutch structure in a lawn mower.

[Conventional technology]

Taking the walk-type lawnmower as an example, in the conventional walk-type lawn mower, the engine is installed in a posture in which the output shaft is directed vertically downward, and the cutting blade is attached to the lower end of this output shaft via a friction-type cutting blade clutch. It is installed (for example, 59-62
No. 734).

[Problems to be solved by the device]

Here, consider a case where the friction clutch is composed of a facing and a metal disk.With the clutch thus configured, carbonized fine powder generated by friction of the facing adheres to the friction surface with use. As a result, if the walking lawn mower is equipped with a clutch at the bottom, sand dust sucked from the surface of the ground, or grass debris on the friction surface, may occur. It may get in and reduce the transmission efficiency.

Therefore, it is conceivable to form a groove on the surface of the facing like a clutch in an automobile to discharge the dust as described above. However, even if a groove is formed on the surface, it is necessary to increase the thickness of the facing in order to maintain the predetermined strength of the facing, so that the operation stroke of the clutch is changed and the space for accommodating the clutch is expanded. Therefore, a relatively large change is required, and it is difficult to realize a small body such as a walk-behind lawnmower because it leads to a change in the shape of the body.

An object of the present invention is to obtain a structure capable of efficiently discharging dust and the like on the friction surface of the cutting blade clutch with the simplest modification possible.

[Means for Solving the Problems]

The feature of the present invention is that a metal disk having a ring-shaped contact surface on its lower surface and a facing having a ring-shaped contact surface on its upper surface are rotatably moved up and down around a vertical axis of rotation. And a friction clutch is formed, the inner peripheral edge of the contacted surface is set to have a larger diameter than the inner peripheral edge of the contact surface, and the outer peripheral portion of the facing is positioned outside the outer peripheral edge of the metal disk. A stepped portion that is recessed below the level of the contacted surface is formed to form a space that expands downward at each of the inside and outside of the ring-shaped contacted surface of the facing in the radial direction. When viewed from the direction along, the groove is formed between the inner peripheral edge and the outer peripheral edge of the contact surface of the metal disk so as to be directed toward the outer side in the radial direction toward the rotation better side. Its action and effect Is as follows.

[Action]

According to the above feature, dust, grass particles, etc. that have entered between the contact surface of the metal disk and the contacted surface of the facing enter the groove as the metal disk rotates, and are sent to the outer peripheral edge by the centrifugal force due to the rotation of the metal disk. Further, the dust, turf strips, and the like that have reached the outer peripheral edge can be dropped to the lower side of the stepped portion, and can be kept away from the friction surface. or,
Since the inner peripheral edge of the contact surface of the metal disk arranged on the upper side is made to overhang inward in the radial direction from the inner peripheral surface of the contacted surface of the facing arranged on the lower side, for example,
Even if dust or grass particles scattered during lawn mowing work approach between the contact surface and the contacted surface, drop the dust or grass particles into the space spreading below the overhanging part to create a friction surface. Can be kept away from.

That is, in the present invention, as a feature of the cutting blade clutch of the lawn mower, the two members rotatable about the longitudinal axis are arranged at the upper and lower positions, so that dust, grass debris, etc. remain between the two members. Although it is easy, it is possible to suppress dust and the like in the groove on the surface of the metal disk arranged on the upper side and the space formed on the inner edge side and the outer edge side of the facing to suppress the trapping on the upper surface of the facing. .

Further, since the groove is formed on the lower surface of the metal disk, dust, grass strips, etc. are less likely to remain inside the groove,
The groove hardly reduces the strength of the metal disk.

[Effect of device]

Therefore, by a relatively simple modification of forming a groove on the metal disk side, a structure was obtained in which dust and the like on the friction surface of the cutting blade clutch were efficiently discharged and a good transmission state was revealed.

In particular, in the present invention, due to the rotation of the clutch, an air current is generated from the central space of the clutch toward the outside through the groove. Therefore, the air current can dissipate heat from the friction surface, and at the same time, the air current can cause dust to flow. It also has the effect of promoting the discharge of.

〔Example〕

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

As shown in FIG. 2 and FIG. 3, the output shaft is provided above the cutting blade housing (3) having a pair of left and right idler wheels (1) at the front and a pair of left and right drive wheels (2) at the rear. An engine (4) with the (4a) facing downward is provided, and a friction clutch (C) and a cutting blade (5) are provided below the output shaft (4a) in a state of being housed in a cutting blade housing (3), and A system for transmitting power from an intermediate portion of the output shaft (4a) to a transmission case (6) for the drive wheel (2) is formed, and further, a grass collector (7) for accommodating the cut grass on the rear surface of the cutting blade housing (3). ) Is attached and a steering handle (8) is provided rearward from the cutting blade housing (3) to form a walk-behind lawn mower.

As shown in FIGS. 1 and 2, the friction clutch (C) is for transmitting the power from the output shaft (4a) to the cutting blade (5), and is provided on the lower surface of the metal disc (9). A transmission state is set by pressure contact between the ring-shaped contact surface (9a) and the ring-shaped contact surface (10a) on the upper surface of the facing (10).

That is, in the friction clutch (C), the bracket (12) is supported at the lower end of the output shaft (4a) via the bearing (11), and the cutting blade (5) is bolted to the bracket (12). 13), the facing (10) is attached to the upper surface of the bracket (12), and a coil spring (14) for separating the bracket (12) and the metal disk (9) from each other. It is provided.

Further, the metal disc (9) can be slid along the rotation axis (Y) of the output shaft (4a) while being driven by the output shaft (4a), and the output shaft (4a) can be moved through the key (15). A plate (16) for externally fitting the metal disk (9) to operate the metal disk (9) downward (in the direction of engaging the clutch) via a bearing (17), A supporting plate (18) and a coil spring (19) for urging the supporting plate (18) downward are provided on the upper part of the plate (16), and between the plate (16) and the supporting plate (18). Is provided with a ball (20) in a state of being engaged with the cam groove.

Also, the support plate (16) houses the metal disk (9),
In addition, when the clutch is disengaged, the metal disk (9) is pressed against the facing (10), and by rotating the support plate (18), the plate (16) and the support plate (18) are separated from each other. Due to this, the lower edge of the support plate (18) and the facing (10) are separated, and the ring-shaped contact surface (9a) of the metal disk (9) is covered by the ring-shaped contact surface of the facing (10). The friction clutch (C) is set in the transmission state by being pressed against the contact surface (10a).

Further, in the friction clutch (C), in order to discharge the dust that has entered the friction surface, as shown in FIG.
... is formed.

That is, in the friction clutch (C), a metal disk is provided between the inner peripheral edge (9b) and the outer peripheral edge (9c) of the ring-shaped contacted surface (9a) when viewed in the direction along the rotary shaft core (Y). (9)
The outer peripheral side of the inner peripheral edge (9b) is formed by contacting the inner peripheral edge (9b) and the outer peripheral edge (9c) in a posture in which the side closer to the rotation side in the rotational direction (F) faces the outer side in the radial direction. Dust that has entered the space (S) surrounded by 9b) is discharged tangentially.

Also, the inner peripheral edge (1) of the contacted surface (10a) of the facing (10)
The radius of 0b) is set larger than the radius of the inner peripheral edge (9b) of the contact surface (9a) of the metal disk (9), and the radially inner side of this metal disk (9) is the inner peripheral edge of the facing (10). (10b) overhangs the contact surface (9
The stepped portion (10d) recessed below the level of the contacted surface (10a) is formed at the position of the outer peripheral edge (9c) of (a), and the contacted surface (1
By forming a space that expands downward at each of the radially inner side of the inner peripheral edge (10b) of 0a) and the radially outer side of the outer peripheral portion, as described above, discharge from the grooves (21). Dropped dust is dropped into the stepped portion (10d) to separate it from the friction surface, and dust that approaches the friction surface from the rotating shaft core side is dropped below the overhang portion to separate it from the friction surface as described above. It is like this.

[Another embodiment]

The present invention can use any metal for the metal disc,
Further, the friction clutch may have any operation structure.

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the present invention is not limited to the structure of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a cutting blade clutch structure in a lawn mower according to the present invention. FIG. 1 is a bottom view showing a contact surface of a metal disk, FIG. 2 is a sectional view showing the cutting blade clutch, and FIG. It is the whole lawn mower side view. (9) …… Metal disk, (9a) …… Contact surface, (9b)…
… Inner rim, (9c) …… Outer rim, (10) …… Facing, (10a) …… Contact surface, (10b) …… Inner rim, (10
d) ... Step, (21) ... groove, (C) ... friction clutch, (Y) ... rotating shaft core.

Claims (1)

[Scope of utility model registration request] 1. A vertically oriented metal disk (9) having a ring-shaped contact surface (9a) formed on its lower surface and a facing (10) having a ring-shaped contact surface (10a) formed on its upper surface. And a friction clutch (C) is formed by rotatably arranging the rotary shaft center (Y) around the rotation axis (Y) and the inner peripheral edge (10b) of the contacted surface (10a) within the contact surface (9a). The diameter is set to be larger than that of the peripheral edge (9b), and the outer peripheral portion of the facing (10) is located outside the outer peripheral edge (9c) of the metal disk (9) and below the level of the contacted surface (10a). The stepped portion (10d) is formed to form a space that expands downward at each of the inside and outside of the ring-shaped contact surface (10a) of the facing (10) in the radial direction. When viewed from the direction along (Y), it extends between the inner peripheral edge (9b) and the outer peripheral edge (9c) of the contact surface (9a) of the metal disk (9). Cutting blade clutch structure in lawn mower which forms the groove of the rolling as the upstream side toward the radially outward side orientation (21).