JP2004236641A - Frame structure of riding mower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body frame of a riding mower enabling easy assembly or maintenance in the frame while keeping the strength. <P>SOLUTION: The body frame 7 of the riding mower is composed of a front-side frame 7A supporting a front wheel 2, provided with a step 30 and supporting a mowing unit 4 in suspended state and a rear-side frame 7B connecting a rear wheel driving part 10. The front-side frame 7A is composed of a pair of right and left frame rods 11 placed opposite to each other interposing a wide gap and a front lateral frame 12 and a rear lateral frame 13 connecting the right and left frame rods 11 at the front part and the rear part. The rear lateral frame 13 has a hollow frame structure protruding upward beyond the frame rod 11. The rear-side frame 7B is composed of a pair of right and left frame plates 14 composed of longitudinal flat plates connected to the rear lateral frame 13 interposing a lateral gap narrower than the front-side frame 7A. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a caster-type front wheel is provided at the front of the fuselage, and a pair of left and right rear wheels that can be shifted independently is provided at the rear of the body, and the mower is positioned between the front wheel and the rear wheel. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure of a riding mower, which is mounted so as to be vertically movable.
[0002]
[Prior art]
Conventionally, as a frame structure of a riding mower having the above-described configuration, a body frame, a front frame portion that supports the front wheels and suspends and supports the mower via a link, and a rear frame portion that connects a rear wheel drive unit. The front frame portion is formed by connecting a left and right front end of a frame pipe made of a square pipe bent in a U-shape in a plan view with a horizontal frame, and a rear frame. A pair of left and right frame plates, each of which is composed of a vertical flat plate opposed to each other with a narrower left and right space than the front frame portion, is connected to a rear horizontal frame portion of the frame rod formed in a U-shape. The upper frame is connected to the rear wheel drive unit and the engine, and the upper frame is erected on a pair of left and right frame plates constituting the rear frame portion. A structure linked with a frame is known (see Patent Document 1).
[0003]
[Patent Document 1]
JP 2000-351330 A
[Problems to be solved by the invention]
In the frame structure of the riding mower described above, since the upper frame is erected on the left and right frame plates and the left and right upper frames are connected by a plurality of horizontal frames, the strength of the front and rear intermediate portion of the body frame is high. On the other hand, the horizontal frame that connects the upper left and right upper frames at a plurality of front and rear places hinders the assembly and maintenance of the structure disposed between the left and right frame plates.
[0005]
In addition, the conventional structure described above adopts a structure in which the front and rear links for suspending and supporting the mower are respectively supported by the frame rods constituting the front frame portion, so that the ground clearance when the mower is raised is sufficient. In order to secure, the height of the fulcrum of the link is raised by increasing the ground height of the frame rod, which may increase the step of boarding and increase the center of gravity of the entire aircraft, This type of riding mower, which runs on slopes and pastures, has room for improvement in terms of aircraft stability.
[0006]
The present invention has been made in view of such a point, and it is possible to easily perform assembly or maintenance while securing the strength of the body frame, and furthermore, the machine body center of gravity is low and excellent in stability. It is a primary object of the present invention to provide an aircraft frame structure of a riding mower that is effective for constructing an airframe.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is characterized in that caster-type front wheels are provided at the front of the fuselage, and a pair of left and right rear wheels that can be shifted independently are provided at the rear of the fuselage, and are located between the front wheels and the rear wheels. A frame structure of a riding mower equipped with a mower suspended so as to be able to move up and down freely, the aircraft frame supporting the front wheels and being equipped with steps, and suspending and supporting the mower via front and rear links. A front frame portion, and a rear frame portion that connects a rear wheel drive portion, and the front frame portion includes a pair of left and right frame rods that are disposed opposite to each other with a large left and right gap, and a left and right frame rod. A front horizontal frame and a rear horizontal frame connected at a front portion and a rear portion, and the rear horizontal frame is formed in a hollow frame shape protruding above the frame rod. The rear frame portion is composed of a pair of left and right frame plates made of a vertical flat plate connected to the rear horizontal frame with a narrower left and right interval than the front frame portion, and the rear wheel drive unit is connected to the rear of both frame plates. It is characterized by having.
[0008]
According to the above configuration, a large bending load is applied to the front-rear intermediate portion of the body frame, that is, a connection portion between the wide front frame portion and the narrow rear frame portion, but the front frame located at this connection portion Since the portion is a rigid structure having a hollow frame shape protruding above the frame rod, it is necessary to provide a large number of reinforcing members above the rear frame portion. It is possible to form a strong body frame, and even if the rear wheel drive unit is connected to the left and right frame plates forming the rear frame unit, the upper part between the left and right frame plates is sufficiently opened.
[0009]
Therefore, according to the first aspect of the present invention, it is possible to enhance the workability of the assembling operation and the maintenance of the rear frame portion while securing the strength of the body frame sufficiently.
[0010]
The frame structure of the riding mower according to the second aspect of the present invention is the invention according to the first aspect, wherein the left and right sides of the fall protection frame formed in a gate shape are provided laterally outside a rear portion of the frame plate constituting the rear frame portion. A base support portion to which a base end portion of a support is connected is provided, and a reinforcing member for connecting the base support portion and the rear horizontal frame is provided on a lateral outer side of the frame plate.
[0011]
According to the above configuration, the load applied to the base end supporting portion connecting the support base end portions of the fall protection frame is supported not only by the frame plate but also by the front frame portion via the reinforcing member.
Further, the front frame portion having a large lateral width and the rear frame portion having a small lateral width are integrated via a reinforcing member, so that the rigidity of the body frame particularly against the lateral bending load is increased.
[0012]
Therefore, according to the second aspect of the present invention, it is possible to firmly connect and support the column base end of the fall protection frame, and to increase the rigidity of the entire body frame, thereby forming a body with excellent durability. Becomes effective.
[0013]
According to a third aspect of the present invention, the frame structure of the riding mower according to the second aspect is configured such that the base support portion is formed in a boss shape into which a support base end of the fall protection frame is inserted from above. The base end of the column of the fall protection frame inserted and mounted on the support is pressed and fixed to the front-rear inner wall surface of the base support by tightening bolts penetrating the base support from the front-rear direction. It is.
[0014]
According to the above configuration, the support base end of the fall protection frame inserted into the boss-shaped base support from above is fixed to the front or rear inner wall surface of the base support by pressing the bolt. And can be firmly connected without rattling. In particular, if the bolts are tightened from behind the base end support portion, the bolts can be operated from a large working space behind the fuselage, and the work of connecting the fall protection frame becomes easier.
[0015]
According to a fourth aspect of the present invention, in the frame structure of the riding mower according to any one of the first to third aspects, the frame structure is located in the rear horizontal frame above the frame rod of the front frame portion. A fulcrum shaft of a rear link for suspending and supporting the mower is supported by a transverse support.
[0016]
According to the above configuration, by setting the fulcrum axis of the rear link for suspending and supporting the mower to be higher than the frame rod, the input rod protruding from the upper surface of the mower while the frame rod in the front frame portion is arranged lower. Can be greatly raised without being disturbed by the fulcrum shaft of the rear link.
[0017]
Therefore, according to the fourth aspect of the present invention, it is possible to secure a large ground clearance of the raised mower while lowering the machine center of gravity by arranging the front frame portion including the steps low. It can be effectively used as the body structure of a riding-type mower that often travels on sloped or uneven terrain.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an overall side view of a riding mower according to the present invention, and FIG. 2 shows an overall plan view thereof. This riding mower is configured as a so-called mid-mount type in which a mower 4 is suspended and supported between front and rear wheels of a riding traveling body 1 having a pair of left and right front wheels 2 and a rear wheel 3 so as to be movable up and down. An engine 5 is mounted on the rearmost portion of the traveling body 1 and a driver seat 6 is provided at a front and rear intermediate portion on the body. Here, a pair of left and right front wheels 2 are formed of caster type idle wheels, and a pair of left and right rear wheels 3 are formed as drive wheels capable of stepless speed change and forward / reverse operation independently of left and right. By driving the rear wheel 3 forward or backward at a constant speed together, the vehicle can travel forward or backward in a straight line, and by giving a speed difference between the left and right rear wheels 3, the vehicle can turn in any direction. Has become.
[0019]
As shown in FIGS. 3 and 4, a body frame 7 of the riding traveling body 1 supports a front wheel 2 and a front frame portion 7 </ b> A that suspends and supports the mower 4 via front and rear links 8 and 9. It is composed of a rear frame 7B for connecting the drive unit 10. The front frame portion 7A includes a pair of left and right frame rods 11 in which channel materials are arranged facing each other with a large left and right interval, and a front horizontal frame 12 made of a channel material that connects front ends of the left and right frame rods 11 to each other. And a rear horizontal frame 13 connecting the rear ends of the left and right frame rods 11 to each other. The rear frame 7B is composed of a pair of left and right frame plates 14 composed of vertical flat plates connected to the rear horizontal frame 13 with a narrower left and right interval than the front frame 7A. A rear wheel drive unit 10 is connected to the rear ends of the left and right frame plates 14, and an engine mounted frame 15 extending rearward from the rear wheel drive unit 10 is provided with air-cooled gasoline. The specified engine 5 is mounted with its output shaft centered in the front-rear direction.
[0020]
The rear horizontal frame 13 is formed in a hollow frame shape of a sheet metal welding structure protruding upward from the frame rod 11, and a fulcrum fitting for pivotally connecting the driver's seat 6 to a front upper end thereof so as to be rotatable around a fulcrum a. A fulcrum shaft 17 connected to the upper end of the rear link 9 for mower suspension is provided inside the rear horizontal frame 13. A single-acting hydraulic cylinder 20 is mounted over a drive arm 18 fixed to the fulcrum shaft 17 and a stay 19 connecting the left and right frame plates 14, and the hydraulic cylinder 20 is extended by supplying hydraulic oil. Then, the rear link 9 is swung up and the mower 4 is driven up, and the hydraulic cylinder 20 is shortened by draining the oil to lower the mower 4 by its own weight. The lowering of the mower 4 is restricted by the contact of the restraining arm 21 extending from the drive arm 18 with the stopper 22 having a spiral stepped contact portion. By changing the position of the contact portion facing the restraining arm 21 by changing the rotation in a stepwise manner, the ground height of the mower 4 at the lower limit is adjusted, and thus the cutting height is changed and adjusted. ing.
[0021]
The mower 4 is configured such that three blades (not shown) that are driven and rotated about the vertical axis are arranged side by side inside the deck 25 and discharge grass from the right end of the deck 25. A gear case 26 is provided at the center of the upper surface of the deck 25, and the rotational power input from the rear to the gear case 26 is converted into longitudinal axis rotation and transmitted to each blade via a transmission belt 27. I have.
[0022]
As shown in FIGS. 7 to 10, bulging portions 13 a protruding forward are formed in the left and right central portions of the rear horizontal frame 13, and concave portions opened downward and rearward inside thereof. When the mower 4 is raised, the gear case 26 and the universal joint 47 enter the recess 28 from below, so that the mower 4 can be raised significantly to secure a large ground clearance. It has become. Further, a flat plate portion 13b connected to the lower end surface of the frame rod is provided continuously below the right and left lower portions of the bulging portion 13a in the rear horizontal frame 13.
[0023]
A step 30 made of sheet metal is mounted and mounted on the front frame portion 7A of the body frame 7 at the foot of the driver's seat 6, and rear wheel fenders 31 are provided on the left and right sides of the driver's seat 6, and the driver's seat is further provided. An engine bonnet 32 is provided behind the vehicle. Then, as shown in FIG. 10, the step 30 is covered with the front frame portion 7A and pressed into a shape that is sunk between the left and right frame rods 11, so that the operation is performed with the step surface lowered. It is configured so that a person can sit on a seat with a low center of gravity. Further, the rear end of the step 30 is mounted and connected to the flat plate portion 13b of the rear horizontal frame 13.
[0024]
As shown in FIGS. 11 and 12, the rear wheel drive unit 10 includes a central transmission case 41 receiving an output from the engine 5, a pair of hydrostatic continuously variable transmissions (HST) 42 connected to the left and right sides thereof. And a pair of left and right deceleration cases 43 supporting the rear wheel 2. The engine power input from the rear to the central transmission case 41 is branched right and left, and the variable displacement pump of each continuously variable transmission 42 is provided. The transmission output from the motor 42 </ b> M of the continuously variable transmission 42 is transmitted to the axle 44 of the rear wheel 2 after being reduced in gear in the reduction case 43. A PTO shaft 45 protrudes from the front surface of the central transmission case 41 and is interlocked to a rearward input shaft 46 of the gear case 26 provided on the upper surface of the mower deck 25 via a pair of universal joints 47 and a transmission shaft 48. .
[0025]
Here, the hydrostatic stepless transmission 42 employs a well-known axial plunger type. By changing the swash plate angle of the pump 42P to change the discharge oil amount and discharge direction, the motor 42M is continuously driven. It is configured to drive forward and reverse. A swash plate angle operation shaft (not shown) and a shift lever 50 arranged to be able to swing back and forth on the left and right sides of the driver's seat 6 are interlocked and connected. The transmission 42 is in the neutral stop state, and the forward shift can be performed by operating the shift lever 50 forward from the neutral position, and the reverse shift can be performed by operating the shift lever 50 backward. In addition, an oil filter 51 located in a hydraulic oil supply oil path to a charge circuit in the hydrostatic continuously variable transmission 42 is mounted on the front surface of the central transmission case 41, and the driver seat 6 is turned forward. When the upper part of the rear wheel drive unit 10 is opened, the oil filter 51 is largely exposed between the left and right frame plates 14 so that a hand can be inserted from above and easily detached.
[0026]
Each of the left and right deceleration cases 43 is provided with a multi-plate type brake 53 acting on a motor shaft 52. The brake operation shaft 53a is connected to a brake pedal 54 disposed near the center of the front of the step via a rod 55 via a rod 55. The left and right brakes 53 are simultaneously linked when the brake pedal 54 is depressed. A parking brake lock pedal 56 for holding the brake pedal 54 at the depressed position is provided on the side of the brake pedal 54.
[0027]
The port block 57 in which the hydraulic circuit of the hydrostatic continuously variable transmission 42 is provided is made of a high-strength cast member that is also used as a lid case of the speed reduction case 43, and a rear frame portion 7 </ b> B of the body frame 7. The rear end of the frame plate 14 is connected to the outer surface of each port block 57, and the front end of the engine mounting frame 15 is connected to the inner side surface of each port block 57.
[0028]
As shown in FIGS. 1 and 5, at the rear of the driver's seat 6, a gate-shaped fall protection frame 61 that can be folded rearward around a fulcrum b at an upper and lower middle portion is provided upright. A base support portion 62 for supporting the left and right support bases 61 a of the right and left columns 61 is provided on the rear outer surface of the left and right frame plates 14 of the body frame 7. As shown in FIG. 15, the base support portion 62 includes a square boss member 63 welded and fixed to the outer surface of the frame plate 14 and a bottom plate member 64 welded and fixed to the outer surface of the frame plate 14 as a reinforcing plate. The square boss members 63 of the left and right base end support portions 62 are connected to each other by stays 73 from the back. Then, in a state where the support base 61a made of a square pipe material is inserted into the base support 62 from above and is received by the bottom plate 64, the support 61 and the support base 61a are inserted from behind. By tightening the inserted bolt 65 into a nut 66 fixed to the front surface of the base support portion 62, the support base end portion 61a is pressed forward by the bolt head and pressed against the front inner surface of the base support portion 62, Thus, the fall protection frame 61 can be firmly erected and fixed firmly without rattling. In this case, the bolt operation can be easily performed from a large space behind the fall protection frame 61.
[0029]
In addition, a reinforcing member 67 made of a plate material is welded to the outer surface of the frame plate 14 with the plate surface turned up and down to increase the strength of the frame 14 itself, and the front and rear ends of the reinforcing member 67 are connected to the front frame portion 7A. Are welded to the rear surface of the rear horizontal frame 13 and to the bottom plate 64 of the base support portion 62. By providing the reinforcing member 67 in this manner, reinforcement is provided at a step connection portion between the wide front frame portion 7A and the narrow rear frame portion 7B, and a base end support for standingly supporting the fall protection frame 61. The strength of the portion 62 is increased.
[0030]
As shown in FIGS. 16 and 17, a battery 68 is mounted on the reinforcing member 67 on the right side of the fuselage, and is fixed via a corner press fitting 69 and a support rod 70. As shown in FIGS. A fuel tank 72 is mounted and supported near the upper end of the horizontal frame 13, the reinforcing member 67 on the left side of the fuselage, and a stay 71 extending from the left frame plate 14.
[0031]
The support structure for the driver's seat 6 is shown in FIGS. A seat support frame 81 is pivotally connected to a fulcrum bracket 16 provided at an upper end portion of a rear horizontal frame 13 constituting the front frame portion 7A so as to be rotatable around a fulcrum a. The driver's seat 6 is mounted so that the position can be adjusted back and forth. On the other hand, a pair of left and right cushion bars 82 for receiving the seat support frame 81 rotated to the sitting posture is mounted on the upper end portions of the left and right frame plates 14 constituting the rear frame portion 7B. Further, the upper portion of the left and right intermediate portions of the rear horizontal frame 13 and the stay 19 are connected by an arcuate reinforcing plate 83, and a spring receiving portion 84 spanned between the reinforcing plate 83 and the left frame plate 14 is provided. A lifting spring 85 having sufficient strength to lift and rotate the vacant driver seat 6 together with the seat support frame 81 is provided. A seating detection switch 86 for detecting the presence of the driver is provided on the frame plate 13c provided above the rear horizontal frame 13 so as to face the seat support frame 81 from below.
[0032]
The seating detection switch 86 is mounted upward on the free end of a leaf spring stay 87 that is bolted to the frame plate 13c in a cantilevered rearward direction. 86a is operated by the free end of an operation lever 88 attached to the base of the stay 87 so as to be able to swing up and down. The operating lever 88 is mounted on the frame plate 13c with the bent portion 88a formed at the base thereof being engaged from above in a pair of front and rear openings 89 formed near the base of the stay 87 and locked. Thus, the bent portion 88a is rotatable only in a certain range in the vertical direction, and is supported so as not to come out of the stay 87.
[0033]
According to the above configuration, in the vacant seat state, as shown in FIGS. 21A and 22, the seat support frame 81 is lifted by the lifting spring 85, and the seating detection switch 86 is turned off. Is detected during traveling, the engine 5 is automatically stopped. In the seated state, as shown in FIG. 21B, when the switch lever 86a is pushed by the operation lever 88, the seating detection switch 86 is turned on, and the engine 5 can be started and continuously operated. . When the seating load is large, the seat support frame 81 compresses the cushion spring 82 and pivots largely downward. In this case, however, the operation lever 88 that has pushed the switch operation section 86a greatly into contact with the stay 87 is contacted. In this state, the stay 87 itself is elastically deformed downward due to the seating load, thereby preventing the seating detection switch 86 from being damaged due to improper load.
[0034]
[Another embodiment]
The reinforcing member 67 does not necessarily need to be a plate member, and may be formed of, for example, a member such as a rod or a pipe that is installed obliquely over the bottom plate member 64 and the rear surface of the rear horizontal frame 13.
[Brief description of the drawings]
FIG. 1 is a left side view of the entire riding mower. FIG. 2 is a plan view of the entire riding mower. FIG. 3 is a plan view of the entire body frame. FIG. 4 is a side view of the entire body frame. FIG. 6 is a side view showing a lower state of the mower mounting part. FIG. 7 is a side view showing a mower rising state of the mower mounting part. FIG. 8 is a side view showing a mower raising state of the mower mounting part. FIG. 9 is a plan view of a front frame portion of the body frame. FIG. 10 is a sectional view taken along line XX in FIG. 9. FIG. 11 is a plan view showing a rear wheel drive portion. FIG. 12 is a part of a rear wheel drive portion. Notched rear view [FIG. 13] Left side view of rear wheel drive section [FIG. 14] Right side view of rear wheel drive section [FIG. 15] Partially cutaway side view showing left base support section of fall protection frame [ FIG. 16 is a plan view showing a mounting portion of the battery. FIG. 17 shows a mounting portion of the battery. FIG. 18 is a side view showing a mounting portion of a fuel tank. FIG. 19 is a plan view showing a mounting portion of a fuel tank. FIG. 20 is a plan view showing a vicinity of a mounting portion of a driving seat. FIG. 21 is a driving seat mounting portion. FIG. 22 is a side view showing an unoccupied state (a) and a seated state (b) of FIG. 22. FIG. 22 is a side view of an unoccupied state showing a means for detecting seating on a driver seat. FIG. 23 is an enlarged plan view of the seating detecting means. Description】
2 Front wheel 3 Rear wheel 4 Mower 7 Body frame 7A Front frame 7B Rear frame 8 Link 9 Link 10 Rear wheel drive 11 Frame rod 12 Front horizontal frame 13 Rear horizontal frame 14 Frame plate 61 Fall protection frame 61a Post base End 62 Base support

Claims (4)

A caster-type front wheel is provided at the front of the fuselage, and a pair of left and right rear wheels that can be shifted independently is provided at the rear of the body, and the mower is suspended between the front and rear wheels so that the mower can be raised and lowered. The frame structure of a riding mower equipped with lowering,
An airframe includes a front frame portion that supports the front wheels and is equipped with steps, and that suspends and supports the mower via front and rear links, and a rear frame portion that connects a rear wheel drive unit. ,
The front frame portion is composed of a pair of left and right frame rods arranged facing each other with a large left and right interval, and a front horizontal frame and a rear horizontal frame connecting the left and right frame rods at a front portion and a rear portion thereof, and a rear portion. The horizontal frame is formed in a hollow frame shape protruding above the frame rod,
The rear frame portion is composed of a pair of left and right frame plates made of a vertical flat plate connected to the rear horizontal frame with a narrower left and right interval than the front frame portion, and the rear wheel drive unit is connected to the rear of both frame plates. The frame structure of a riding mower characterized by being provided. It is a frame structure of the riding mower of Claim 1, Comprising:
At the rear lateral outer side of the frame plate constituting the rear frame portion, a proximal end support portion is provided to which the left and right column proximal ends of the fall protection frame formed in a gate shape are connected. The frame structure of a riding mower, wherein a reinforcing member for connecting the base support portion and the rear horizontal frame is provided. The frame structure of a riding mower according to claim 2, wherein the base support portion is formed in a boss shape into which a support base end portion of the overturn protection frame is inserted from above, and is inserted into the base support portion. Riding mowing configured to fix the support base end portion of the mounted fall protection frame to the front-rear inner wall surface of the base support portion by tightening bolts penetrating the base support portion from the front-rear direction. Machine frame structure. It is a frame structure of the riding mower according to any one of claims 1 to 3,
A frame structure of a riding mower, wherein a fulcrum shaft of a rear link for suspending and supporting the mower is supported in a horizontal position in the rear horizontal frame above the frame rod of the front frame portion.

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