JP3140132B2 - Power work machine clutch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch device in a power working machine such as a power lawn mower, which can connect a clutch driven member to a power output shaft in a sharp and smooth manner.

[0002]

2. Description of the Related Art A power working machine of Japanese Patent Application No. 2-234546 filed by the present applicant is configured as shown in FIG. That is, a drive V pulley 02 for driving a rear wheel is integrally fitted to a lower portion of a crankshaft 01 of an engine (not shown) by a key 03, and a conical surface which expands outwardly as it proceeds downward at the lower portion of the outer edge of the drive V pulley 02. Clutch drive member 04
Are formed integrally, and a friction material 05 is integrally adhered to the lower surface of the conical surface clutch driving member 04. Further, a blade holder 08 is fitted to a cylindrical portion 06 integral with the drive V pulley 02 via a bearing 07, and a rotary blade 010 is integrally attached to the plate holder 08 by bolts 09. A disc-shaped receiving piece 011 is applied to the lower end surface of the inner 07a of the bearing 07, and the blade holder 08 and the rotary blade 010 are screwed through the receiving piece 011 and screwed to the lower end of the crankshaft 01.
Are supported so as not to fall downward.

Further, an upper cylindrical portion 08 of a blade holder 08
The driven sleeve 013 is spline-fitted to the inner peripheral surface of
At the upper end of the driven sleeve 013, a conical-surface clutch driven member 014 is formed integrally with a friction member 05 on the lower surface of the conical-surface clutch driving member 04 so as to be able to freely contact and separate. A flange-shaped driven disk 015 is integrally formed on the outer edge of the driven member 014, and a disc-shaped clutch spring 016 is interposed between the driven disk 015 and the blade holder 08. The conical surface is formed by the spring force of the clutch spring 016. The clutch driven member 014 is pushed upward and pressed against the friction material 05 of the conical clutch driving member 04.

Further, a pair of left and right brackets projecting from a lower part of a main body of a power lawn mower (not shown) as a power working machine.
017 and the fork base 019 of the clutch arm 018
It is pivotally mounted so that it can swing up and down around the center. Moreover, the clutch arm 018 has a conical surface clutch driving member 04.
An opening 021 having a diameter larger than that of the opening 021 is provided substantially concentrically.
Friction material 02 on the lower surface of clutch arms 018 on both the left and right sides
When the clutch arm 018 swings downward about the bolt 020, the friction material 022 can come into contact with the upper surface of the driven disk 015.

Further, the lower end of the clutch cable 024 is locked in a notch 023 near the tip of the clutch arm 018 from the friction material 022, and a brake spring 025 is interposed between the tip of the clutch arm 018 and the lower surface of the power lawn mower main body. When the upward operating force does not act on the clutch cable 024, the clutch arm 018 is swung downward around the bolt 020 by the spring force of the brake spring 025, and the driven sleeve 013, the blade holder 08 and the rotary The blade 010 is braked by the friction material 022, and when an upward operation force exceeding the spring force of the brake spring 025 is applied to the clutch cable 024, the clutch arm 018 swings upward around the bolt 020. Then, the braking of the driven sleeve 013, the blade holder 08 and the rotary blade 010 by the friction material 022 is prevented. It is adapted to be divided. A driven pulley (not shown) for driving the rear wheels of the power lawn mower and a drive V pulley 02
A belt 026 is stretched over, and the rear wheels are driven to rotate as the drive V pulley 02 rotates.

[0006]

The clutch device shown in FIG. 4 has a more reliable fitting and disengagement operation and a simpler structure than a conventional clutch device in which a ball falls into or out of a cam recess. The driven sleeve 013 of the clutch device shown in FIG. 4 is spline-fitted to the upper tubular portion 08a of the blade holder 08 and is not supported by other portions, so that the upward spring force of the clutch spring 016 and the clutch arm 018 The downward operating force is applied to the driven sleeve 013
In contrast, if the center line does not coincide with the center line of the crankshaft 01, the driven sleeve 013 and the conical surface clutch driven member 014 tilt up and down to tilt, and the conical surface clutch driven member 014 moves up and down.
May not be uniformly pressed against the friction material 05 of the conical surface clutch driving member 04, and as a result, the disconnection of the clutch may not be good.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a clutch device for a power working machine which overcomes such difficulties, and relates to a power working machine for rotating a working portion from a power output shaft via a clutch. In the clutch device, the clutch is a cone type in which each clutch sliding surface of a clutch driving member and a clutch driven member has a conical surface shape, and a clutch driving member, a clutch driven member and The working unit holder is provided in this order, and the working unit holder is axially immovable with respect to the power output shaft and is rotatably supported on the power output shaft, and the clutch driven member is spline-connected to the working unit holder. The outer peripheral portion of the end face of the clutch driven member and the working unit holder is formed on a surface substantially perpendicular to the axis of the power output shaft, The outer edges of both end faces are arranged with a gap required for switching from the clutch engaged state to the clutch disengaged state, and a clutch spring for biasing the both end faces in a direction to mutually expand is interposed. Things.

The present invention is constructed as described above. Therefore, when the clutch disengaging operation force for moving the clutch driven member away from the clutch driving member by overcoming the spring force of the clutch spring is applied, the clutch is The outer peripheral portion of the end surface of the driven member can be in close contact with the outer peripheral portion of the end surface of the working portion holder over the entire circumference. It can be stopped and the stopped state can be held firmly.

In the clutch disengaged state, the opposite edges of the opposite end faces of the clutch driven member and the working unit holder are in close contact over the entire circumference, and the rotation center line of the clutch driven member coincides with the axis of the power output shaft. Therefore, when the clutch disengagement operation force on the clutch driven member is released, the conical surface of the clutch driven member is brought into contact with the conical surface of the clutch driving member by the spring force of the clutch spring interposed between the both end surfaces. As a result of uniform contact with the entire surface of the sliding contact surface while avoiding partial contact, the transmission torque in the clutch connected state is remarkably large, and the friction of the clutch sliding contact surface is reduced as much as possible, resulting in low durability. Improve greatly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 3 will be described below. A power lawn mower 1 which is a kind of a power working machine includes a front wheel 3 and a rear wheel 4 at four front and rear corners of a cutter housing 2, and has an engine 5 mounted on the cutter housing 2, and a rear upper part of the cutter housing 2. A handle 6 is integrally attached, and a glass bag 7 for storing cut grass is provided behind the cutter housing 2. The engine 5 is a vertical engine in which a crankshaft 8 serving as a power output shaft is oriented vertically, and a drive V pulley 9 for the rear wheels 4 is provided below the crankshaft 8.
Are fitted together by a key 10 and the drive V pulley 9
A conical-surface clutch driving member 11 is formed integrally at the lower portion of the outer periphery of the conical-surface clutch driving member 11 and spreads outward as it goes downward, and a friction material 12 having high heat insulating property is integrally adhered to the lower surface of the conical-surface clutch driving member 11. Have been.

Further, a cylindrical portion 13 integral with the drive V pulley 9
Abuts on the lower end surface of the
, A blade holder 15 is fitted thereto, and a rotary blade 19 as a driven member is integrally attached to the blade holder 15 by bolts 18. Further, a ring-shaped projection 16 is protruded from the center of the upper end surface of the blade holder 15, and a contact surface 17 perpendicular to the center line of the crankshaft 8 is formed on the outer edge of the upper end surface of the blade holder 15. Have been. In addition, a disc-shaped receiving piece 20 is applied to the lower end surface of the inner 14a of the bearing 14, and the bolt 21 screwed to the lower end of the crankshaft 8 through the receiving piece 20 causes the blade holder 15 and the rotary blade 19 to rotate. Is supported via a bearing 14 so as not to fall downward.

A ring-shaped groove 23 is formed in a lower portion of a conical-surface clutch driven member 22 having a shape capable of coming into and out of contact with the friction material 12 on the lower surface of the conical-surface clutch driving member 11 and a conical-surface clutch. A cylindrical portion 24 is formed at the center of the driven member 22, and a flange-shaped driven disk 25 is integrally formed at an outer edge of the conical clutch driven member 22, and the ring-shaped groove is formed.
The inner peripheral surface near the outer edge of 23 is formed on a cylindrical guide surface 26, and the outer peripheral surface near the center of the ring-shaped groove 23 of the conical surface clutch driven member 22 and the inner peripheral surface of the ring-shaped protrusion 16 of the blade holder 15 are formed. Is a spline fit 27 and a ring-shaped groove
The cylindrical guide surface 26 near the outer edge of 23 is fitted tightly against the outer peripheral surface of the ring-shaped projection 16 of the blade holder 15,
In addition, the outer edge of the lower end surface of the driven disk 25 of the conical surface clutch driven member 22 can come into contact with the contact surface 17 of the blade holder 15 so as to be able to freely contact and separate.

Further, a clutch spring 28 is interposed between the upper surface of the blade holder 15 and the lower surface of the driven disk 25 of the conical surface clutch driven member 22, and the conical surface clutch driven member 22 is moved by the spring force of the clutch spring 28. The frictional material of the conical clutch drive member 11 is pushed upward.
It is designed to be pressed against 12. Further, a pair of left and right brackets 29 is protruded downward from the lower part of the main body of the power lawn mower 1, and the bracket 29 has a two-pronged base 31 of a clutch arm 30.
Are pivotally mounted on the bolt 32 so as to be swingable up and down, and a nut (not shown) is screwed to a tip of the bolt 32.

An opening 33 having a diameter larger than that of the conical clutch driving member 11 is provided substantially concentrically on the clutch arm 30, and a friction material 34 is integrally formed on the lower surface of the clutch arm 30 on the left and right sides of the opening 33. When the clutch arm 30 swings downward about the bolt 32, the friction material 34 can come into contact with the upper surface of the driven disk 25. Further, as shown in FIG. 1, the lower end of the clutch cable 36 is locked in the notch 35 at the tip of the clutch arm 30, and the brake spring is connected between the tip of the clutch arm 30 and the lawn mower body 37.
In the state where the upward operating force does not act on the clutch cable 36, the clutch arm 30 is swung downward around the bolt 32 by the spring force of the brake spring 38, and the brake spring 38 When an upward operation force exceeding the spring force is applied to the clutch cable 36, the clutch arm 30 can swing upward around the bolt 32.

Further, a V-belt 39 is bridged between a driven V-pulley (not shown) and a driving V-pulley 9 (not shown) at the rear of the lawn mower main body 37. It is supposed to be. A one-way clutch, a rear wheel drive clutch and a speed reducer are interposed between the driven pulley and the rear wheel 4, and the rotation torque of the crankshaft 8 is transmitted to the rear wheel 4 by the one-way clutch. The rotational torque is not transmitted from the rear wheels 4 to the crankshaft 8.

Since the embodiment shown in FIGS. 1 to 3 is constructed as described above, when the clutch cable 36 is loosened and the rear wheel drive clutch is released, the clutch spring 28 exceeds the upward spring force. The clutch arm 30 is pivoted downward by the downward spring force of the brake spring 38, and the conical-surface clutch driven member 22 and the driven disk 25 are lowered, and the conical-surface clutch is moved from the friction material 12 of the conical-surface clutch drive member 11. When the driven member 22 separates, power transmission from the crankshaft 8 to the blade holder 15 and the rotary blade 19 is cut off, and at the same time, power transmission from the crankshaft 8 to the rear wheel 4 is cut off.
The rotary blade 19 and the rear wheel 4 stop. When the rear wheel drive clutch is switched to the connected state while the rotary blade 19 and the rear wheel 4 are stopped, the power of the engine 5 is transmitted from the crankshaft 8 to the rear wheel 4, and the power lawn mower 1 can run. It becomes a state.

Next, when an upward operating force is applied to the clutch cable 36 by overcoming the downward spring force of the brake spring 38, the clutch arm 30 swings upward around the bolt 32 and contacts the upper surface of the driven disk 25. The friction material 34 on the lower surface of the clutch arm 30 that has been moved away from the driven disk 25 releases the braking force of the rotary blade 19, and the conical surface clutch driven member 22 rises due to the upward spring force of the clutch spring 28. Conical surface clutch drive member
The power of the engine 5 is transmitted from the crankshaft 8 to the rotary blade 19 by being pressed against the friction material 12 on the lower surface of the engine 11,
The rotary blade 19 is driven to rotate.

When the upward operating force of the clutch cable 36 is reduced while the rotary blade 19 is directly connected to the crankshaft 8 and is being rotated, the clutch arm 30 swings downward due to the downward spring force of the brake spring 38. The power transmission of the engine 5 is interrupted by moving the conical clutch driven member 22 away from the friction material 12 of the conical clutch driving member 11, and the friction material 34 on the lower surface of the clutch arm 30 Since the braking force is generated by pressing against the upper surface, the rotary blade 19 can be stopped immediately.

Also, when the conical surface clutch driven member 22 moves up and down by the upward operating force on the clutch cable 36 exceeding the downward spring force of the brake spring 38 or the spring force of the brake spring 38, the conical surface clutch driven A cylindrical guide surface 26 near the outer edge of the ring-shaped groove 23 of the member 22
Since the conical-surface-shaped clutch driven member 22 slides up and down while being guided by the outer peripheral surface of the ring-shaped protrusion 16 of the blade holder 15, the resultant force of the upward spring force of the clutch spring 28 or the friction material 34 of the clutch arm 30 Driven disk 25
The resultant force of the downward clutch disengaging force acting on the upper surface of the cylindrical guide surface 26 does not coincide with the center line of the crankshaft 8 and the eccentric force for inclining the conical-surface clutch driven member 22 acts. By the guide sliding with the outer peripheral surface of the ring-shaped projection 16, the conical surface clutch driven member 22 can be moved up and down without tilting, and the friction material 12 of the conical surface clutch driving member 11 and the conical surface clutch driven member 22 Local partial contact can be reliably prevented, the sharpness of the clutch can be improved, and the clutch can be switched on and off smoothly. Further, since there is no local contact between the conical surface clutch driving member 11 and the conical surface clutch driven member 22, local wear of both can be prevented, and the durability of the clutch device can be greatly improved.

Even when the cylindrical guide surface 26 and the outer peripheral surface of the ring-shaped projection 16 are worn and rattled, when the clutch is switched from the engaged state to the disengaged state, the cone-shaped clutch driven member 22 will tilt. Also, the outer edge 25a of the lower end surface of the driven disk 25 of the conical-surface clutch driven member 22 abuts against the contact surface 17 of the blade holder 15, and the inclination of the conical-surface clutch driven member 22 is reduced. Friction member 12 of conical clutch driving member 11 and conical surface clutch driven member 22
, And the clutch can be maintained at a high level of disconnection and durability.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of a clutch device for a power working machine according to the present invention.

FIG. 2 is an enlarged vertical sectional side view of a main part in a clutch connected state of the embodiment.

FIG. 3 is an enlarged longitudinal sectional side view of a main part of the embodiment in a clutch disengaged state.

FIG. 4 is an enlarged longitudinal sectional side view of a main part of a clutch device of a conventional power working machine.

[Explanation of symbols]

1: Power lawn mower, 2: Cutter housing, 3: Front wheel,
4 rear wheel, 5 engine, 6 handle, 7 glass bag, 8 crankshaft, 9 drive V pulley,
10 ... key, 11 ... conical surface clutch driving member, 12 ... friction material, 13 ... cylindrical part, 14 ... bearing, 15 ... blade holder, 16 ... ring projection, 17 ... contact surface, 18 ... bolt, 19 …
Rotary blade, 20: receiving piece, 21: bolt, 22: conical surface clutch driven member, 23: ring-shaped groove, 24: cylindrical part,
25 ... driven disk, 26 ... cylindrical guide surface, 27 ... spline fitting, 28 ... clutch spring, 29 ... bracket, 30
... clutch arm, 31 ... two-pronged base, 32 ... bolt, 33 ... opening, 34 ... friction material, 35 ... notch, 36 ... clutch cable,
37 ... lawn mower body, 38 ... brake spring, 39 ... V belt.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasutomo Abe 1-4-1, Chuo, Wako-shi, Saitama Pref. Honda Technical Research Institute Co., Ltd. (56) References JP-A-64-46022 (JP, A) Hei 4-119226 (JP, A) Japanese Utility Model Showa 52-42476 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16D 13/32

Claims (1)

(57) [Claims] 1. A clutch device for a power working machine that rotates a working unit from a power output shaft via a clutch, wherein the clutch has a conical surface in each of a clutch driving member and a clutch driven member. The power output shaft is provided with a clutch driving member, a clutch driven member, and a working unit holder in this order, and the working unit holder cannot move in the axial direction with respect to the power output shaft. Heck one rotatably pivotally supported, said clutch driven member is spline-coupled to the working part holders, before
Opposite ends of the clutch driven member and working unit holder
The outer edge of the plane is formed on a plane substantially perpendicular to the axis of the power output shaft.
And the outer edges of both end faces are in the clutch connected state.
With the clearance required to switch from
Are arranged and biased in a direction in which the end faces are mutually expanded.
A clutch device for a power working machine, wherein a clutch spring is interposed .