JPH0597056A - Under carriage structure of agricultural working machine - Google Patents

Abstract

PURPOSE:To improve rigidity and machining ability of an under carriage and to facilitate assembly by increasing the width of the lateral distance of the central part of a frame and meanwhile producing a difference in a level between the front end side and the rear end side by bending downward a rear end, and bringing the frame in the vicinity of a rear axle into an approximately horizontal state. CONSTITUTION:A pair of right and left truck frames 15 and 15 are formed of a round pipe, and the size of a distance between the right and left is increased in order of a front part width W1, a rear part width W2, and a central part width W3 (W1<W2<-, W3), and the total widths of the central parts of the frames 15 and 15 are increased in a lateral direction to a value higher than the widths of front and rear parts. Engine bases 22 and 22 are welded and secured to a steering gear case bracket 17 to integrally form the three members. The rear width W2 part of the frames 15 and 15 are folded down to a level below those of a front part, as seen from a side, and central widths W1 and W3 parts and rear frame parts 15a and 15a are arranged in a horizontal state in a lower position having a specified difference L in a level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chassis structure of an agricultural working machine such as a riding lawn mower.

[0002]

2. Description of the Related Art When a chassis is composed of a pair of left and right track frames, a member having a cross-sectional shape in a plan view is provided over the entire length, or, for example, as shown in Japanese Patent Application No. 2-128232. There is a means for bending the rear end of the frame upward to improve the rigidity of the frame.

[0003]

However, in the former case, the track frame is formed flat and has excellent workability, but on the other hand, there is a problem that the torsional rigidity is low. In the latter case, the rear wheel side There has been a problem that the rear-end bent portion is subjected to upward bending stress due to the axle reaction force.

[0004]

Therefore, according to the present invention, the left and right track frames that form the chassis are formed by round pipes, and the width of the left and right spaces at the center of these frames is expanded, while the rear ends of these frames are folded downward. By bending, a low step is formed between the frame and the front end side, and the frame near the rear axle is configured to be substantially horizontal. In addition, an engine base for mounting the steering case of the engine and the steering case and a steering case seat are integrally fixed between the left and right track frames to form a chassis.
It is intended to improve strength.

[0005]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view of main parts, FIG. 2 is a side view of the entire lawn mower, and FIG. 3 is a plan view thereof. In the figure, (1) is a riding lawn mower, and (2) is front and rear wheels (3). A chassis frame having (4), (5) an engine mounted on the front part of the frame (2), (6) a bonnet covering the engine (5),
(7) is a steering handle provided on the rear part of the bonnet (6), (8) is a step, (9) is a rear body cover, (1)
(0) is a driver's seat provided on the cover (9), (11) is a lawn mower arranged below the step (8), and (1)
2) is a cut grass transporting thrower arranged on the right side of the mower (11), and (13) is connected to the rear end of the chassis frame (2) through a stay (14) to store cut grass from the thrower (12). It is a grass collection tank.

As shown in FIG. 4 to FIG. 7 and FIG. 10, the pair of left and right track frames (15) and (15) arranged in the front and rear direction of the chassis frame (2) are formed by round pipes, and the left and right spaces are formed. Width is front width (W1) / rear width (W2)
The widths (W1 <W2 <W3) are increased in order of the central width (W3) so that the overall central widths of the frames (15) and (15) are expanded laterally as compared with the front and rear end portions, while the left and right frames (15) are
A front axle case (16) is provided between the front widths (W1) of (15), a gear case bracket (17) which is a steering gear case seat is provided between the front portions of the central width (W3), and a front part of the rear width (W2) is provided. The left and right fixed brackets (18a) and (18b) vertically erected between the frames (15) and (15) are used for the seat bracket (19), and the rear steering width (W2) is provided between the seat bracket (19) and the rear width (W2). The chassis (2) is configured by connecting and fixing the rear ends (W2) of the rear ends of the brackets (20) with the rear frame (21).

The left and right engine bases (22) and (22) carrying the engine (5) are welded and fixed to the left and right frames (15) and (15) and the steering gear case bracket (17) in a three-piece manner, and the gate is also installed. Forming the step (8) into a left and right frame (15)
The left and right frames (15) (1) are fixed by welding to the brackets (23) fixed to the outside of the center width (W3) of the (15).
The step (8) is integrally supported on the step (5).

Further, the rear width (W2) portions of the frames (15) and (15) have a front portion in a side view and a central width (W1) (W).
Bend downward from part 3), and after this, frame part (15
a) (15a) is provided horizontally at a low position having a constant step (L), and the rear frame parts (15a) (1)
5a) Rear axle bracket (26) via bolt (25) to bracket (24) (24) fixed to the outside
(26) are attached respectively, and left and right rear wheels (4)
The rear axle cases (28) and (28) respectively supporting the axles (27) and (27) of (4) are attached to the bracket (2).
6) and (26) are connected to each other via horizontal swing pivot shafts (29) and (29). The rear axle brackets (26) and (26) surround the transmission case (31) that integrally connects the hydraulic continuously variable transmission (HST) (30) that drives the rear wheels (4) and (4) to the front part from the left and right. ), The rear frame portion (15a), the rear axle bracket (26), and the transmission case (31) are mutually improved in rigidity to reduce their weight.

The seat bracket (19) is formed by bending both sides of the front end of the flat T-shape to form a gate-shaped cross section, and the bent portions (19a) (19a) on both sides are fixed to the left and right fixing brackets (18a) (18b). ) And the rear end bent portion (19b) are welded and fixed to the rear frame (21) so that the axle transmission case (3) of the axle (27) is fixed.
2) A seat bracket (19) is arranged above. The rear steering gear case bracket (20) is provided between the seat bracket (19) and the axle transmission case (32), and the bracket (20) has a mountain shape in a rear view and has left and right rear frame portions (15a).
By connecting the (15a), the mission case (31)
And a phase switching case (33) which is a rear steering gear case for switching the rear wheels (4) to the same phase or opposite phase when steering the four wheels (3) and (4),
The bracket (20) is installed on the chevron top (20a), and the left and right track frames (15) (15) and the gear case bracket (20) receive the reaction force from the rear wheel (4) from the ground and are rigid. It is configured to improve.

As shown in FIGS. 8 and 9, the steering mechanism (34) using the handle (7) is a sector gear arranged on the left side of the center of the machine, which is connected to the handle shaft (7a) via a pinion gear (35). (36), a pitman arm (38) connected to the gear (36) via a pitman shaft (37), a front wheel provided between the knuckle arm (39) of the left front wheel (3) and the pitman arm (38). Steering intermediate shaft (40) and the intermediate shaft (40)
The first and second steering arms (41) (42) of the pitman arm (38) and the knuckle arm (3
Front wheel first and second drag rods (43) and (44) respectively connecting 9) and tie rods (46) connecting the knuckle arm (45) of the right front wheel (3) and the knuckle arm (39). And the phase switching case (33)
Rear wheel drag rod (48) that connects the switching arm (47) of the above and the sector gear (36), and the left and right rear wheel tie rod arms (49a) (4) of the case (33).
9b) and left and right tie rods (51a) (51b) connecting the left and right rear wheel knuckle arms (50a) (50b) fixed to the rear axle case (28).
When steering the wheels (3) and (4), the sector gear (36) and the drag rod (48) are interlockingly connected through the end shaft (52) to perform four-wheel (3) (4) steering, while the end shaft ( When the gear 52) is disengaged from the sector gear 36, only the front wheels 3 are steered.

By the way, as shown by the phantom line in FIG. 5, the engine (5) is mounted obliquely with respect to the center of the machine body to avoid interference between the air cleaner (53) and the bonnet (6), and the bonnet ( 6) The size and weight of the chassis can be reduced, and the tilt angle between the chassis frame (2) and the engine (5) makes these vibration directions different to prevent resonance and improve vibration damping effect. It is configured to let.

Further, as shown in FIGS. 1 and 6, the left and right side plates (54a) (54a) of the operation column (54) fixed to the left and right track frames (15) (15) are fixed to the engine ( 5) The fuel tank (56) is installed, and the stay (55) is a tank (56).
It has a recessed tank mounting surface (55a) along the shape of the bottom surface, and an oil escape port (57) is opened on the mounting surface (55a).
External lead-out hose (58) connected to the oil outlet (57)
Therefore, at the time of fuel injection, the fuel spilled on the tank mounting surface (55a) is discharged to the outside to improve its safety, and the left and right side plates are formed by the stays (55) forming the recessed mounting surface (55a). By connecting (54a) and (54a) to each other, the rigidity of this column (54) is improved.

Further, the left fixing bracket (18
The shaft (59) and the rear frame (2) protruding from the left outer side of a)
A battery cradle (60) is provided between the upper left end of 1), and the battery (61) installed in the cradle (60) is made to face the left side in the seat bracket (19) to improve its safety. I am configuring.

This embodiment is constructed as described above, and the entire center width of the left and right track frames (15) is expanded in the lateral direction as compared with the front and rear end portions, and at the same time, the frame (1
5) By bending the rear end downward to form the lower rear frame portion (15a) having the step (L), the strength of the entire track frame (15) can be improved and the track frame (15) can be improved. The mower (11) can be easily attached to the central portion with good strength. Further, the mission case (31) is integrally mounted so as to be surrounded by the left and right rear axle case brackets (26) (26) below the gear case bracket (20) fixed between the left and right track frames (15) (15). These track frames (15) and brackets (2
0) ・ The mutual strength of the mission case (31) can be improved, and the reaction force from the ground via the rear wheel (4) can also be applied to the frame (15), bracket (20), case (3).
In 1), it can be effectively received and the rigidity can be improved.

[0015]

As is apparent from the above embodiments, according to the present invention, the left and right track frames (15) that form the chassis are formed of round pipes, and the width (W3) between the center portions of the frames (15) is set to be equal to each other. While expanding these frames (1
5) The rear end is bent downward to form a low step (L) between the rear end and the front end side, and the frame (15) near the rear axle (27) is configured to be substantially horizontal. The rigidity of the chassis formed by the left and right track frames (15) can be improved, and the frame (15) near the rear wheel (4) can also be formed in a horizontal shape to improve workability. The transmission (30) and the mission case (3
Incorporation of 1) and the like can be facilitated and favorably made possible. Also, the engine (5) and steering handle (7)
The engine base (22) and the steering case seat (17) to which the respective steering cases are attached are integrally fixed between the left and right track frames (15), respectively. (22) The rigidity of the three members can be improved and the weight of each of these parts can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of a chassis frame portion.

FIG. 2 is an overall side view.

FIG. 3 is an overall plan view.

FIG. 4 is a side view of the lawnmower.

FIG. 5 is an explanatory plan view of a body frame portion.

FIG. 6 is a front explanatory view of the lawnmower.

FIG. 7 is a rear view of the lawnmower.

FIG. 8 is an explanatory diagram of a steering mechanism section.

FIG. 9 is a rear explanatory view of a steering mechanism section.

FIG. 10 is an explanatory plan view of a chassis frame portion.

[Explanation of symbols]

 (5) Engine (7) Operating handle (15) Truck frame (17) Case bracket (case seat) (22) Engine base (L) Step (W3) Width

Claims (2)

[Claims] 1. The left and right track frames that form the chassis are formed of round pipes, and the width of the left and right spaces at the center of these frames is expanded, while the rear ends of these frames are bent downward to lower the space between them. An undercarriage structure of an agricultural work machine, characterized in that the frame near the rear axle is formed to be substantially horizontal. 2. An undercarriage of an agricultural work machine, wherein an engine base for mounting a steering case for an engine and a steering case for a steering handle, and a steering case seat are integrally fixed between left and right track frames to form a chassis. Construction.