JPH0456574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a drive-side clutch disk of a clutch for a cutting blade that is slidably attached to a drive-side shaft, and a drive-side clutch disk that is attached to the drive-side clutch disk. A brake disk is disposed on the opposite side of the mower blade side clutch disk, and a spring is provided that biases the drive side clutch disk away from the mower blade side clutch disk and presses against the brake disk. The present invention relates to a lawn mower in which a cam mechanism for slidingly operating a side clutch disk is provided in a state in which the cam mechanism is manually operated.

[Conventional technology]

The above-mentioned lawn mower is designed to provide safety by applying braking force through the drive-side clutch disc so as to apply rotational resistance to the drive-side shaft so as to stop the engine when the clutch is in the disengaged state. It is something.

Conventionally, this type of lawn mower has a fixed brake disc, which has caused the following inconveniences.

[Problem that the invention seeks to solve]

In other words, when the clutch is engaged, the gap between the driving side clutch disk and the brake disk becomes small, and this gap can become clogged with dust and foreign matter such as grass debris, which can damage the disk or cause frictional heat damage. Ta. If the gap between the driving side clutch disk and the brake disk is set wide to prevent dust clogging, the operating stroke required for clutch operation becomes large, resulting in poor operability.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to enlarge the gap between the drive side clutch disk and the brake disk when the clutch is engaged, and to make it possible to reduce the operating stroke required for clutch operation.

[Means for solving problems]

The present invention is characterized in that, in the above-mentioned lawn mower, the brake disc is slidably attached to the driving side clutch disc in the sliding direction, and when the clutch is in a disengaged state, the brake disc is attached to the driving side clutch disc. The cam mechanism is caused to act on the brake disc in a state in which the brake disc is slid toward a side closer to the side clutch disc, and when the clutch is engaged, the brake disc is slid toward a side away from the drive side clutch disc. Its functions and effects are as follows.

[Effect]

The cam mechanism moves both the driving side clutch disk and the brake disk toward each other to bring them into contact, and moves both toward apart to engage the clutch and close both disks. Because they are separated, compared to the conventional system in which only the drive side clutch disk is moved and the brake disk is fixed, even if the movement stroke of the drive side clutch disk is the same, the movement of the drive side disk and brake disk when the clutch is engaged is The gap becomes larger.

〔Effect of the invention〕

Compared to the past, the gap between the drive side clutch disk and the brake disk can be expanded when the clutch is engaged while keeping the movement stroke of the drive side clutch disk the same.This allows the gap between the drive side clutch disk and the brake disk to be cleaned from dust and dirt. It can be made large to prevent foreign objects from clogging, and the disc is less likely to be damaged, resulting in a long service life and safety.Furthermore, the movement stroke of the drive-side clutch disc can be kept to a minimum. The operating stroke required for clutch operation is small, making it possible to achieve excellent operability.

〔Example〕

As shown in Fig. 4, a pair of left and right front wheels 1, 1
The rear wheels 2 and the cutting blade 3 are mounted on the upper side of a cutting blade housing 4 which also serves as a machine body frame and has rear wheels 2, 2 and has a cutting blade 3 inside thereof so as to be rotatable around a vertical axis P. Along with attaching a driving engine 5,
A vertical drying handle 6 and a grass collecting bag 7 are attached to the rear of the housing 4 to constitute a self-propelled walk-behind lawn mower.

As shown in FIG. 1, inside the cutting blade housing 4, a bearing 11 is attached to the lower end of a driving-side cylindrical shaft 10 that is externally fitted onto the engine output shaft 8 in the vertical direction of the machine body and is interlocked with a key 9. The mower blade side clutch disk 12 is attached so as to be relatively rotatable through the mower blade side clutch disk 12, and the driving side clutch disk 13 disposed above the mower blade side clutch disk 12 is rotated integrally by engagement with the key 9. so, and,
It is attached to the driving side cylinder shaft 10 so as to be able to slide up and down by the action of the keyway, and the spring 1
4, the clutch disk 12 on the cutting blade side is biased to move up and away from the cutting blade side clutch disk 12, and the rotational force of the drive side cylinder shaft 10 is frictionally transmitted to the cutting blade attachment 15. It consists of 16.

The side opposite to the mowing blade side clutch disk 12 with respect to the driving side clutch disk 13, that is,
The brake disk 17 disposed above the drive side clutch disk 13 is connected to the drive side cylinder shaft 10 so as to rotate relative to it and slide up and down via a bearing 18.
At the same time, it engages with a locking tool 21 fixed to the cutting blade housing 4 via a locking disk 20 installed on the driving side cylinder shaft 10 through a bearing 19 so as to be relatively rotatable and slidable up and down. I've let it happen. A first spring receiver 22 is located above the brake disc 17 and is attached to the drive side cylinder shaft 10 so as to be slidable up and down. The brake disc 1 is caused by the contact with the attached second spring receiver 23 and the contact of the bearing 19 with the first spring receiver 22, respectively.
7 is set, and the driving side clutch disk 13 separated from the cutting blade side clutch disk 12 is configured to be pressed against the brake disk 17 by the spring 14. The friction brake 24 is configured so that when the clutch 16 is in the disengaged state, a braking force is applied to the driving side cylinder shaft 10 via the driving side clutch disk 13.

The through hole 25 of the brake disk 17 through which the tongue portion 20a of the locking disk 20 is inserted so as to be able to move up and down relative to each other is formed into a long hole as shown in FIG. Although the brake disc 17 is allowed to rotate reciprocally with respect to the cutting blade housing 4 within the interior, a locking disc 20 and a locking tool 21 are installed to prevent the brake disc 17 from rotating beyond the set angle. It is configured to be stopped by the cutting blade housing 4 via the cutting blade housing 4. and between an upward concave portion provided in the locking disk 20 with a depth varying in the circumferential direction and a downward concave portion provided in the brake disc 17 with a depth variable in the circumferential direction. The brake disc 17 is urged downward by a charge spring 27 provided between the first spring receiver 22 and the second spring receiver 23 via the first spring receiver 22 and the bearing 18, with a cam ball 26 interposed therebetween. The locking disk 20 is configured to be pressed against the cam ball 26, and the locking disk 20 is biased upward by the spring 14 via the driving side clutch disk 13 and the bearing 19 to be pressed against the cam ball 26. . An operating lever 30 is interlocked and connected via a release wire 29 to a swing operating arm 28 that is rotatably provided on the brake disc 17.
, so that the vertical handle 6 swings around the axis X.
The clutch disk 13 and the brake disk 17 on the driving side are slid together by the manual operation force of the operating lever 30 or the biasing force of the springs 14 and 27 to operate the clutch disk 16 and the brake disk 24. The cam mechanism 31 is configured to turn on and off. That is, the operating arm 28 is in the first operating position A.
1, the spring 14
and 27, the driving side clutch disk 13 is operated away from the cutting blade side clutch disk 12, and the brake disk 17 is slid to the side approaching the driving side clutch disk 13. , 17 are pressed together. When the operating arm 28 is operated to the second operating position B, as shown in FIG. 2, the driving side clutch disk 13 is pressed downwardly against the cutting blade side clutch disk 12 while compressing and deforming the spring 14. And, while compressing and deforming the charge spring 27, the brake disc 1
7 to the side away from the driving side clutch disk 13.

The operation lever 30 is placed in the first operation position (OFF).
When the operating lever 30 is operated to the second operating position (ON), the operating arm 28 is moved to the first operating position A, and when the operating lever 30 is operated to the second operating position (ON), the operating arm 28 is moved to the second operating position B.
The operating lever 30 is configured to be biased to the first operating position (OFF) by the action of the springs 14 and 27 and the cam ball 26, and the operating lever 30 is The brake 2 is operated by gripping it together with the vertical handle 6.
4 in the brake release state and the clutch 16 in the engaged state, and even if the gripping force applied to the operating lever 30 is slightly reduced, this reduction will be applied to the charge in the compressed state. Supplemented by the elastic restoring force of the spring 27,
This ensures that the clutch 16 remains engaged.

In other words, just by letting go of the drying vertical handle 6,
The operating lever 30 is in the first operating position (OFF),
The clutch 26 is automatically disengaged so that the inertial rotation of the cutting blade 3 is not transmitted to the cylinder shaft 10, the brake 24 is switched to a braking state, the engine 5 is stopped, and the machine is stopped. At this time, since the clutch 26 is set to the cut state, the cutting blade 3 becomes in a free rotation state and tries to continue rotating due to inertia force, but rotation is prevented by frictional resistance due to contact with the lawn. The rotation of the engine will stop after a short period of time has passed since the engine stopped.

[Brief explanation of the drawing]

The drawings show an embodiment of a lawn mower according to the invention,
1 and 2 are sectional views of the clutch and brake, FIG. 3 is a plan view of the operating arm arrangement, and FIG. 4 is a side view of the entire walk-behind lawn mower. 3...Mower blade, 10...Drive side shaft, 12...Mower blade side clutch disk, 13...Movement side clutch disk, 14...Spring, 16...Clutch, 17...Brake disk, 31...Cam mechanism.

Claims (1)

[Claims] 1. The driving side clutch disk 13 of the clutch 16 for the cutting blade 3 is slidably attached to the driving side shaft 10, and the driving side clutch disk 13
A brake disk 17 is disposed on the opposite side of the clutch 16 from the cutting blade side clutch disk 12, and the driving side clutch disk 13 is biased away from the cutting blade side clutch disk 12, and the brake disk The lawn mower is provided with a spring 14 that presses against the drive side clutch disk 17, and a cam mechanism 31 that is manually operated to slide the drive side clutch disk 13, the brake disk 17 is connected to the drive side clutch disk In addition to being slidably installed in the sliding direction of 13,
When the clutch 16 is in the disengaged state, the brake disc 17 is connected to the driving side clutch disc 1.
3, and when the clutch 16 is in the engaged state, the brake disc 1
7 is slid toward the side away from the drive side clutch disk 13, and the brake disk 1
A lawn mower in which the cam mechanism 31 is applied to the cam mechanism 7.