JPH0158778B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to walk-behind working vehicles in general, in which a pair of left and right running wheels are integrally driven in the same rotational direction, and a state where only one of the wheels is driven is stopped. The present invention relates to a wheel clutch which can be switched between a state and an idle state in which each rotation is freely possible.

[Prior art]

For example, when configuring a walk-behind lawn mower so that it can be operated by itself or by being pushed by hand, it is possible to configure the machine to be self-propelled or manually moved. However, when the aircraft is self-propelled, if only one wheel can be stopped, the orientation of the aircraft can be easily adjusted by driving one wheel, and when the aircraft is moving by hand,
If the left and right wheels are placed in an idle state where they can each rotate separately, the aircraft orientation can be easily adjusted due to the differential rotation of the left and right wheels. As such a clutch, there has conventionally been a steering clutch configured to be able to drive and stop the left and right wheels separately. In other words, by operating the left and right wheels so that they are both stopped, the left and right wheels are put into an idle state where they can rotate independently. Further, this clutch was designed to drive and stop the left and right wheels using a pair of operating tools.

[Problems to be Solved by the Invention] With conventional clutches, it is necessary to operate both of a pair of operating tools in order to switch the left and right wheels between the integral driving state and the separate free running state. I was at a disadvantage.

It is an object of the present invention to provide a system for easily switching the left and right wheels between a state in which they are driven integrally, a state in which only one of them is driven, and a state in which each wheel rotates freely. The purpose is to make the structure easy to obtain.

[Means to solve the problem]

The wheel clutch for a walk-behind work vehicle according to the present invention is characterized in that a first wheel drive shaft and a second wheel drive shaft, which are individually linked to a pair of left and right traveling wheels, are arranged concentrically, A side rotating body is attached to the first wheel drive shaft so as to be relatively rotatable, and a first clutch wheel body for the driving side rotating body is set at an entry position close to the driving side rotating body and a disengagement position spaced apart from the driving side rotating body. The second clutch wheel body is attached to the first wheel drive shaft so as to be able to rotate integrally with the first wheel drive shaft, and the second clutch wheel body is connected to the first clutch wheel body in a slidable manner.
The clutch wheel is disposed on the opposite side of the drive-side rotating body and is slidable between an engaged position close to the first clutch wheel and a disengaged position spaced apart from the second clutch wheel. A first spring is provided which is integrally and rotatably attached to the second wheel drive shaft in a state in which the first clutch wheel body is separated from the driving side rotating body, and the first clutch wheel body and the second clutch wheel A second spring is provided between the bodies, and one operation tool is interlocked to slide the second spring against the second clutch wheel, thereby joining the first clutch wheel and the driving side rotating body. The elastic restoring force of the first spring in the state is
By setting the elastic restoring force of the second spring to be smaller than the elastic restoring force of the second spring in the state in which both the clutch rings are connected, the operation and effect are as follows.

[Effect]

As the operating tool is moved toward the clutch engaged position, the second clutch wheel slides toward the first clutch wheel, and this sliding force is transmitted by the second spring to drive the first clutch wheel. Due to the sliding toward the side rotating body and the difference in elastic restoring force between the first spring and the second spring, the first clutch wheel first connects to the driving side rotating body and only the first wheel drive shaft is connected. is interlocked and connected to the driving side rotating body. As the operating tool is further operated from this position to the clutch engaged position, the second clutch wheel slides toward and joins the first clutch wheel while elastically deforming the second spring, and the second clutch wheel is connected to the first clutch wheel. Since the drive shaft is interlocked and connected to the first wheel drive shaft and the first clutch wheel body is first joined to the driving side rotating body,
Both wheel drive shafts are interlocked and connected to the driving side rotating body. When the operating tool is placed in the clutch disengaged position, the first clutch wheel body is separated from the driving side rotating body by the first spring, the interlocking between the first wheel drive shaft and the driving side rotating body is released, and the second clutch wheel body is separated from the driving side rotating body by the first spring. is the first
The second wheel drive shaft is separated from the clutch wheel body, and the interlocking of the second wheel drive shaft with respect to each of the driving side rotating body and the first wheel drive shaft is cut off.

By arranging both the first and second clutch wheels on the same lateral side of the driving side rotating body, both clutch wheels can be operated with one operating tool. This can be done simply by interlocking only the second clutch wheel with the operating tool. In other words,
Like a conventional clutch in which the first clutch wheel and the second clutch wheel are arranged separately on both sides of the driving rotating body, both clutch wheels slide in opposite directions when the operating tool is operated. In other words, the operating system must be provided with a structure so that the operating force is branched and transmitted to both clutch wheels, and the direction of action of the operating force on both clutch wheels is reversed. It's over.

〔Effect of the invention〕

Switching between the integrated drive state of the left and right wheels, the state where only one is stopped, and the free running state where each wheel can rotate independently can be done with a simple operation of one operating tool, making it possible to switch between self-propelled and manual driving. Transfer switching and single-wheel drive made maneuvering to orient the aircraft easier and faster.

Since the above-mentioned operating force branching and transmitting structure is not required, the operating system can be simplified in structure and economically advantageous.

〔Example〕

As shown in FIG. 5, a pair of left and right front wheels 1
a, 1b, drivable rear wheels 2a, 2b, an engine 3, a control handle 4, etc.,
A reel-type lawn mowing cutter 5 is installed so as to be freely drivable while being disposed at the front end inside the cut grass scattering prevention cover 6, and a cut grass container 7 is placed inside the cover 6 so that the cut grass is not scattered backward by the rotation of the cutter 5. The walk-behind mower is configured to collect and store cut grass, and to be inserted and removed from the rear of the machine.

In order to drive the cutter 5 and the rear wheels 2a, 2b, an engine 3 is used as shown in FIG.
A belt tension type main clutch 8 is attached to the output shaft 3a of the
Intermediate transmission shaft 9 which is interlocked so that transmission can be cut freely via
is provided above the front end side of the cover 6 while being installed inside the first transmission case 10, and the intermediate transmission shaft 9
is interlocked and connected to the rotating support shaft 5a of the cutter 5 via a transmission chain 12 inside the case 11. A second transmission case 15 is provided above the rear end side of the cover 6, and is configured to input the rotational force of the intermediate transmission shaft 9 into a deceleration mode via the worm gear type reduction mechanism 13 and the rotary transmission shaft 14. , one 18 of the first and second output shafts 17 and 18 of the wheel clutch 16 internally housed in the second transmission case 15
is operatively connected to the left rear axle in the case 19a through an internal transmission chain 20a, and the other output shaft 17 is operatively connected to the right axle through an internal transmission chain 20b in the case 19b.

The clutch 16 is constructed as shown in FIG.

That is, the pair of first and second output shafts 1
7 and 18 are arranged concentrically, and on the first output shaft 17,
The driving-side rotary body 21 is coupled to the input shaft 26 via a gear 22, a transmission shaft 23, and bevel gears 24 and 25, and is fitted onto the outside so that only relative rotation is possible. The first clutch wheel body 27 for the driving side rotating body 21 is attached to the first output shaft 17 by spline engagement so as to rotate and slide together, and the first clutch wheel body 27 is brought close to the driving side rotating body 21. 2
When the clutch pawl 27a of No. 7 and the clutch pawl 21a of the driving side rotating body 21 are engaged, the clutch pawl 27a of the driving side rotating body 21 is brought into the engaged position and remains engaged with the first output shaft 17.
Both clutch pawls 21 are spaced apart from the driving side rotating body 21 so that the driving side rotating body 21 and the first output shaft 17 are interlocked and connected to rotate together.
When the engagement between a and 27a is released, the cutting position is reached and the driving side rotating body 21 and the first output shaft 17 can be rotated relative to each other. The second clutch wheel 28 relative to the first clutch wheel 27,
The driving side rotating body 21 with respect to the first clutch wheel body 27
The clutch of the second clutch wheel 28 is attached to the second output shaft 18 by spline engagement so that it rotates and slides therewith, and is placed close to the first clutch wheel 27. Claw 28a
When the clutch pawl 27b of the first clutch ring 27 is engaged, the clutch is in the engaged position and remains engaged with the second output shaft 18, and both output shafts 1
When the clutch pawls 28a, 27b are disengaged by interlocking the clutch pawls 28a, 27b such that they are integrally rotated and separated from the first clutch ring body 27, the clutch is in the disengaged position and both output shafts are connected. 17,1
8 relative rotations are possible.

Then, a first spring 29 is placed between the driving-side rotating body 21 and the first clutch wheel 27 by slidingly contacting at least one of the driving-side rotating body 21 and the first clutch wheel 27 to prevent their relative rotation. and the first clutch wheel 27 by elastic compression deformation.
The first clutch wheel body 27 is separated from the drive side rotary body 22 by elastic restoring force, and the first clutch wheel body 27 and the second clutch wheel body 27 are separated from each other by the elastic restoring force. clutch wheel body 2
8, the second spring 30 is brought into sliding contact with at least one of the first and second clutch rings 27 and 28 to enable relative rotation therebetween, and the second clutch is rotated by elastic compression deformation. The first of the rings 28
It is interposed in such a way as to allow access to the clutch wheel 27. The elastic restoring force of the first spring 29 when the first clutch wheel 27 and the driving side rotating body 21 are in an interlocking state is the same as the elastic restoring force of the second spring 30 when the first clutch wheel 27 and the second clutch wheel 28 are in an interlocking state. Both springs 29 and 30 are set to have a restoring force smaller than the elastic restoring force of . In other words, the second clutch wheel 2
8 is slid toward the entry position, this operating force is transmitted via the second spring 30,
As shown in FIG. 2, the first clutch body 27 is engaged with the driving side rotating body 21, and the second clutch ring body 28 is further slid, so that as shown in FIG. The second spring 30 is elastically deformed using the clutch wheel body 27 as a reaction force point to engage the first clutch wheel body 27, and as shown in FIG. When the clutch is slid, the first clutch wheel 27 is also slid to the cut position by the elastic restoring force of the first spring 29. Then, a swinging shift fork 31 which is slidably operated on the second clutch wheel body 28, this fork 31
The shift fork operating arm 3 is attached to the protrusion of the rotation support shaft 32 from the second transmission case 15.
3. One lever-type operating tool 35 linked via each of the release wires 34 is provided near the grip portion of the handle 4 so that it can be gripped and operated together with the operating lever 36 of the main clutch 8 and the operating handle 4, respectively. When the operating tool 35 is swingably mounted and is in the first operating position (OFF), both clutch wheels 27 and 28 are in the cut position as shown in FIG. 1, and the left and right rear wheels 2a and 2b are When the operating tool 35 is set to the second operating position A so that the main push movement state in which the aircraft is in an idle state in which each part can be rotated independently, the first clutch wheel The operating tool 35 is set to the third operating position (ON) so that only the body 27 is in the entry position and a drive steering state is created in which only the right rear wheel 2b is driven so that the aircraft is oriented. When operated, both clutch wheels 27 and 28 are engaged together as shown in FIG. 3, and the left and right rear wheels 2a and 2 are engaged.
A self-propelled state of the aircraft is created in which the robots b are integrally driven in the same rotational direction.

[Application example]

The output shafts 17 and 18 can be changed to axles, and these are connected to the first wheel drive shaft 1 which is linked to the wheels.
7 or the second wheel drive shaft 18.

INDUSTRIAL APPLICATION This invention is applicable to various walk-behind work vehicles, such as a walk-behind tiller and a binder.

[Brief explanation of drawings]

The drawings show an embodiment of the wheel clutch for a walk-behind work vehicle according to the present invention, in which FIG. 1 is a sectional view of the wheel in an idle state, FIG. 2 is a sectional view of the drive steering state, and FIG. 3 is a sectional view of the wheel in the wheel drive state. FIG. 4 is a sectional view of the state, FIG. 4 is a transmission system diagram, and FIG. 5 is an overall side view of the walk-behind lawn mower. 2a, 2b... Wheels, 17... First wheel drive shaft, 18... Second wheel drive shaft, 21... Driving side rotating body, 27... First clutch wheel, 28... Second
Clutch wheel body, 29...first spring, 30...
...Second spring, 35...Operation tool.

Claims (1)

[Claims] 1 A first wheel drive shaft 17 and a second wheel drive shaft 1 that are respectively linked to a pair of left and right running wheels 2a, 2b.
8 are arranged concentrically, and the driving side rotating body 21 is attached to the first wheel drive shaft 17 so as to be relatively rotatable, and the first clutch wheel body 27 is connected to the driving side rotating body 21.
is attached to the first wheel drive shaft 17 so as to be able to freely rotate integrally with the first wheel drive shaft 17 in a slidable state between an entry position close to the driving side rotating body 21 and a cut position away from the driving side rotating body 21. The second clutch wheel 28 relative to the clutch wheel 27 is disposed on the opposite side of the first clutch wheel 27 from the drive-side rotating body 21 side, and the second clutch wheel 28 is close to the first clutch wheel 27. The first clutch wheel body 27 is attached to the second wheel drive shaft 18 so as to be able to rotate integrally with the second wheel drive shaft 18 in a slidable state between an engaged position and a disengaged position separated from the second clutch wheel body 28. A first spring 29 is provided which is operated away from the second clutch wheel 21, and a second spring 30 is provided between the first clutch wheel 27 and the second clutch wheel 28. One operating tool 35 is interlocked so as to perform a sliding operation, and the first spring 2 is in a state where the first clutch wheel body 27 and the driving side rotating body 21 are connected.
The elastic restoring force of 9 is applied to both the clutch wheels 27, 2.
8, the elastic restoring force of the second spring 30 is set to be smaller than the elastic restoring force of the second spring 30 in the connected state of No. 8.