JPH057417A - Running type lawn mower - Google Patents

Abstract

PURPOSE:To constitute a running type lawn mower so as not to loose a transmission belt from a motor to a mower while providing a structure of a mower capable of vertically absorbing unevenness of the ground in the running type lawn mower. CONSTITUTION:A mower 7 is coupled in the middle of a machine body frame 1 supported with front wheels 2 and rear wheels 3 and interchange part 11a permitting dislocation of a mower to the upper part to a machine frame 1 is provided in a coupling part between the machine body frame 1 and the mower 7 and a transmission belt 28 is wound over an output pulley of output shaft of an engine 4 carried backward than the mower 7 and input pulley 27 of input shaft of the mower 7. Then a spring 30 for pulling and pressing the mower 7 forward by pulling force is installed and connected in the machine body frame 1 and mower 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mower support structure for a walking lawn mower.

[0002]

2. Description of the Related Art In a walk-behind lawnmower, for example, as disclosed in Japanese Unexamined Patent Publication No. 3-83510, a mower (refer to FIG. 6 of the above publication) in the middle of a machine frame supported by front wheels and rear wheels. Some support 8). In this case, an accommodation (see FIG. 1 of the above-mentioned publication) is provided at the connecting portion between the machine body frame and the mower so that the mower can move upward when the mower rides on the convex portion of the ground.

[0003]

In the above-mentioned walk-behind lawn mower, the engine (3 in FIG. 6 of the above publication) is mounted on the rear part of the body frame, and the input pulley of the input shaft of the mower (see the above publication). 6-10) and the output pulley of the engine output shaft (9 of FIG. 6 of the publication) are wound around the transmission belt (11 of FIG. 6 of the publication) to drive the mower. Has been done.

In this case, when the mower is supported by combining the links so that it can be displaced upward, the tension of the transmission belt tends to pull the mower as a whole toward the rear side.
The tension of the transmission belt tends to loosen. Then, in this state, if the front part of the mower rides on the convex part of the ground and the mower rises to the front, the tension of the transmission belt is greatly relaxed, and the power of the engine is not transmitted to the mower. An object of the present invention is to provide a structure in which the mower can be displaced upward to absorb the unevenness of the ground, and the power of the engine is reliably transmitted to the mower.

[0005]

The feature of the present invention resides in that the above-mentioned walk-behind lawnmower is constructed as follows. That is, by connecting the mower in the middle of the body frame supported by the front wheels and the rear wheels, a flexible portion that allows the mower to be displaced upward with respect to the body frame is provided at the joint portion between the body frame and the mower. The transmission belt is wound around the output pulley of the output shaft of the engine mounted on the rear side and the input pulley of the input shaft of the mower, and a spring that pulls and urges the mower forward is installed over the fuselage frame and the mower. It is connected.

[0006]

With the above-described structure, the mower is pulled toward the front by the urging force of the spring as a whole, so that the transmission belt between the engine and the mower is stretched to prevent the transmission belt from loosening. .. Then, when the mower tries to move up and down due to the action of the interchange part provided in the connecting portion between the airframe and the mower, the spring expands and contracts in accordance with this movement, so that the mower moves over the convex portion of the ground. However, it is not disturbed by this spring.

[0007]

As described above, while the mower is provided with the structure capable of being displaced upward to absorb the unevenness of the ground, the slack of the transmission belt is prevented and the power of the engine is surely transmitted to the mower. It was possible to improve the reaping performance of the walk-behind lawnmower without any uncut residue.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a walk-behind lawnmower, in which a pair of caster-type front wheels 2 are supported on the front part of a machine body frame 1 constructed by welding square pipes, and a pair of rear wheels is provided on the rear part of the machine body frame 1. A pair of left and right wheels 3 are supported. Then, the engine 4 and the fuel tank 5 are provided at the rear of the body frame 1.
And a steering handle 6 is provided.

The mower 7 is supported between the front wheels 2 and the rear wheels 3 of the machine body frame 1. Next, the support structure of the mower 7 will be described. As shown in FIGS. 1 and 2, one support shaft 12 is rotatably supported on the rear side of the front wheel 2 of the machine body frame 1, and the support shaft 12 has an L-shaped first support arm 8 thereon. The left and right pairs are fixed.
Two support shafts 1 are provided on the front side of the rear wheel 3 in the body frame 1.
3 is fixed, and a pair of left and right L-shaped second support arms 9 are provided on the support shaft 13 so as to be vertically swingable.
A link rod 10 is erected and connected across the first and second support arms 8 and 9.

As shown in FIGS. 1, 2 and 3, a total of four sets of link links 11 which can swing back and forth are supported on the front, rear, left and right portions of the mower 7, and each of these four sets of link links 11 is supported. It is connected to one end of the first and second support arms 8 and 9. In this case, the first and second link links 11
A long hole 11a (corresponding to an interchangeable portion) is provided in a connecting portion with the supporting arms 8 and 9, and the first and second supporting arms 8 and 9 are provided.
On the other hand, the mower 7 can be moved upward by the length of the elongated hole 11a. The mower 7 can also move in the left-right direction due to the left and right play of the connecting portion between the link link 11 and the mower 7 and the left and right play of the connecting portion between the link link 11 and the first and second support arms 8 and 9. Is configured as follows.

As shown in FIGS. 1 and 2, a boss portion 14 is vertically swingably supported around a horizontal axis P1 of the machine body frame 1, and an operating rod 15 having a handle 15a is rotatable. The operation rod 15 is inserted and supported by the boss portion 14, and the end portion of the operation rod 15 is connected to the arm 12a of the support shaft 12 in a structure that allows the rotation. A screw portion is provided on the inner surface of the boss portion 14 and the outer surface of the operation rod 15, and when the operation rod 15 is turned by the handle 15a, the operation rod 15 can be moved in the axial direction by the action of the screw. As a result, when the operator holds the handle 15a and rotationally operates the operation rod 15, the support shaft 12 is rotationally operated and the first and second support arms 8 and 9 are vertically swung, so that the mower with respect to the machine body frame 1 is moved. The position of 7 can be changed up and down. Even if the hand is released from the handle 15a, the mower 7 does not descend due to the screw action of the boss 14 and the operating rod 15, and the position of the mower 7 is held.

Even if there is a convex portion on the ground and the roller 7a of the mower 7 rides on the convex portion, the link link 11
The upward movement of the mower 7 is allowed by the accommodation effect of the long hole 11a. In addition, the left and right backlash of the connecting portion between the link link 11 and the mower 7, the link link 11 and the first and second
The mower 7 also moves in the left-right direction due to the back-and-forth play of the connecting portion with the support arms 8 and 9.

Next, the transmission structure from the engine 4 to the mower 7 will be described. As shown in FIGS. 1, 2, and 4, a first output pulley 17 and a second output pulley 18 are fixed to a downward output shaft 16 of the engine 4, and a hydrostatic continuously variable transmission 19 for the rear wheel 3 is provided. A transmission belt 21 is wound around the input pulley 20 and the second output pulley 18. A vertically extending relay shaft 22 is supported on the rear side of the mower 7,
A transmission belt 25 is wound around the relay pulley 23 on the upper side of the relay shaft 22 and the first output pulley 17.

A deep groove type relay pulley 24 is fixed to the lower side of the relay shaft 22. On the contrary,
The input shaft 26 of the mower 7 also has a deep groove type input pulley 2
7 is fixed, and a transmission belt 28 is wound around the relay pulley 24 and the input pulley 27. A tension pulley 31 is arranged to stretch or loosen the transmission belt 25 to perform transmission or transmission interruption operation to the input pulley 27, and the transmission belt 28 is also provided with a wide tension pulley 29.

In this case, the mower 7 by the operating rod 15
The relay pulley 24 and the input pulley 27 are set to have the same height at an intermediate position in the range for adjusting the vertical position of the vehicle, and the transmission belt 28 is displaced up and down with the relay pulley 24 as a fulcrum so that the machine frame It absorbs the vertical movement of mower 7 with respect to 1.

As shown in FIGS. 1 and 2, a pair of left and right springs 30 are provided across the left and right sides of the front support shaft 12 and the rear upper surface of the mower 7. Therefore, this spring 3
Due to the urging force of 0, the mower 7 is pulled toward the front wheel 1 side as a whole, and the mower 7 tends to rotate counterclockwise in FIG. 1. As a result, the transmission belt 28
Tension is maintained and tension is maintained. Then, as shown in FIG. 1, when the spring 30 is installed diagonally, the action of trying to lift the mower 7 as a whole also works, so that when there is a convex portion on the ground, the mower 7 is smoothly displaced upward, It goes over this convex part.

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

[Brief description of drawings]

[Figure 1] Overall side view of a walk-behind lawnmower

[Fig. 2] Overall plan view of a walk-behind lawnmower

FIG. 3 is a vertical cross-sectional front view of the vicinity of a link link that connects the mower and the second support arm.

FIG. 4 is a schematic side view showing a transmission system from the engine to the mower.

[Explanation of symbols]

 1 Airframe Frame 2 Front Wheel 3 Rear Wheel 4 Engine 7 Mower 11a Interchange Section 16 Engine Output Shaft 17 Engine Output Pulley 25, 28 Transmission Belt 26 Mower Input Shaft 27 Mower Input Pulley 30 Spring

Claims (1)

Claims: 1. A mower (7) is connected in the middle of a body frame (1) supported by front wheels (2) and rear wheels (3).
A flexible portion (11a) that allows upward movement of the mower (7) with respect to the airframe (1) is provided at a connecting portion between the airframe frame (1) and the mower (7), and the mower (7) is provided.
Output shaft (16) of engine (4) mounted further rearward
The transmission belts (25) and (28) are wound around the output pulley (17) and the input pulley (27) of the input shaft (26) of the mower (7), and the mower (7) is moved forward. A walk-behind lawn mower in which a spring (30) for pulling and urging is attached to the body frame (1) and the mower (7) in an erected manner.