JP2022178137A - Grass mower - Google Patents

Abstract

To provide a four-wheel-drive grass mower preventing oil leak problem caused by wear of a seal part of an axle unit in a simple and inexpensive configuration and preventing cut grass, mud, pebbles, etc. from scattering from an interval between front wheels and rear wheels.SOLUTION: A grass mower includes: a steering case 7 fitted and pivoted to lower fitting parts 6a, where a seal member S attached to the steering case for inserting the lower fitting parts 6a extending downward from transmission cases 6 at both left/right ends of an axle unit U for driving front wheels 1 and 1; an elastic front cover F suspendingly extending to near the ground, provided at the axle unit U front side; an elastic outer periphery cover 9 suspending, in plan view, to a position substantially along a rotation locus outer peripheral edge R of the mowing blade 4 and to the rearward position of the front wheels 1 and 1, provided at a front end of a mowing blade cover 8 for covering a mowing blade 4; and a longitudinal scattering prevention plate 10 suspendingly extending to a substantially same height position as the lowest position of the lowered mowing blade 4, provided left/right inward the steering case 7 in a rotating direction side from the forefront position of the rotating mowing blade 4 and between the elastic front cover F and the elastic outer periphery cover 9.SELECTED DRAWING: Figure 1

Description

In a four-wheel drive mower, the present invention prevents oil leakage from the axle unit between the left and right front wheels and also prevents cut grass from scattering from the opening between the rear side of the front wheels and the front side of the mowing device. It is related to the configuration of the machine.

2. Description of the Related Art Conventionally, a four-wheel drive type mower is known, in which front wheels are driven by a front axle unit attached in a center pivot form capable of laterally swinging about a pivot shaft in the longitudinal direction of a vehicle body. It is These axle units adopt a form in which the steering case is fitted and pivotally supported in the lower fitting portion extending downward from the transmission case at both left and right ends. It is inserted into a seal member such as an oil seal or a dust seal attached to the steering case and supported by a bearing in the steering case. When the operator performs a steering operation in a state where mud scattered by the rotation of the cutting blade adheres to the seal member, the steering case rotates around the lower fitting portion, and the inner lip portion of the seal member and the lower fitting portion are engaged. The joint slides, and the adhering mud acts as an abrasive, and the sealing effect of the sealing member is lost. In particular, the lower fitting portion of the transmission case, which is made of an aluminum-based material, wears out in a short period of time, causing the problem of leakage of oil in the steering case. In addition, the four-wheel drive type front wheels have a wide range of operation during steering operation, and it is necessary to widen the distance between them and the harvester. In addition, fungi in the ground and soil adhere to fruits and leaves, making fruit trees susceptible to disease.

JP 2014-236675 A

The present invention is a four-wheel drive mower that has a simple and inexpensive structure, prevents oil leakage due to wear of the seal portion of the axle unit, and prevents grass clippings, mud, pebbles, etc. from scattering from the gap between the front wheel and the mowing device. The challenge is to provide the machine.

According to the first aspect of the invention, a reaper K having a cutting blade 4 rotating substantially horizontally is provided on the abdomen of a vehicle body 3 on which a pair of left and right front wheels 1, 1 and rear wheels 2, 2 are suspended so as to be vertically movable. In a four-wheel drive lawn mower capable of driving the mowing device K, the front wheels 1, 1 and the rear wheels 2, 2 by a prime mover 5 provided at the rear of the vehicle body 3, the front wheels 1, 1 are center-pivoted to the vehicle body 3. A steering case 7 is fitted with a sealing member S which is transmitted by an axle unit U supported so as to be swingable, and through which a lower fitting portion 6a extending downward from the transmission case 6 at both left and right ends of the axle unit U is inserted. is fitted and pivotally supported in the lower fitting portion 6a, and an elastic front cover F is provided on the front side of the axle unit U, extending between the left and right front wheels 1, 1 to near the ground, and covering the cutting blade 4. At the front end of the cutting blade 4, an elastic outer peripheral cover 9 is provided at a position substantially along the outer peripheral edge R of the rotation locus of the cutting blade 4 in a plan view, and at a position behind the front wheels 1, 1. The cutting blade 4 is suspended from the left and right inner sides of the steering case 7 in the direction of rotation from the position and between the elastic front cover F and the elastic outer peripheral cover 9 to substantially the same height as the cutting blade 4 lowered to the lowest position. The lawn mower is provided with anti-scattering plates 10 in the front-rear direction.

A pair of front and rear link arms 11 and 12 are arranged on the left and right sides, and the upper front ends of the link arms 11 and 12 are pivotally supported on the vehicle body 3 side, and the lower rear ends thereof on the cutting blade cover 8 side. is moved up and down in a substantially horizontal state, and the scattering prevention plate 10 is attached to the lower side of the axle unit U by tilting it rearward and outward in a plan view, and the rear lower part of the scattering prevention plate 10 is rearward and upward. The configuration is that of a lawn mower that is directed and cut.

Further, the lawn mower is constructed such that the elastic front cover F and the front end of the anti-scattering plate 10 are spaced apart from each other.

According to the first aspect of the invention, a reaper K having a cutting blade 4 rotating substantially horizontally is provided on the abdomen of a vehicle body 3 on which a pair of left and right front wheels 1, 1 and rear wheels 2, 2 are suspended so as to be vertically movable. In a four-wheel drive lawn mower capable of driving the mowing device K, the front wheels 1, 1 and the rear wheels 2, 2 by a prime mover 5 provided at the rear of the vehicle body 3, the front wheels 1, 1 are center-pivoted to the vehicle body 3. A steering case 7 is fitted with a sealing member S which is transmitted by an axle unit U supported so as to be swingable, and through which a lower fitting portion 6a extending downward from the transmission case 6 at both left and right ends of the axle unit U is inserted. is fitted and pivotally supported in the lower fitting portion 6a, and an elastic front cover F is provided on the front side of the axle unit U, extending between the left and right front wheels 1, 1 to near the ground, and covering the cutting blade 4. At the front end of the cutting blade 4, an elastic outer peripheral cover 9 is provided at a position substantially along the outer peripheral edge R of the rotation locus of the cutting blade 4 in a plan view and at a position behind the front wheels 1, 1, so that the rotating cutting blade 4 The grass clippings and mud that scatter from the ground are blocked by the elastic front cover F that extends between the front wheels 1, 1, and are prevented from scattering forward of the vehicle body 3. The elastic outer cover 9 hanging down at a position substantially along the front wheels 1, 1 and behind the front wheels 1, 1 discharges dirt and dust picked up by the rotation of the cutting blade 4 from the inside of the cutting blade cover 8 forward or sideways. can be suppressed. In addition, the cutting blade 4 lowered to the lowest position is located between the elastic front cover F and the elastic outer peripheral cover 9 and between the elastic front cover F and the elastic outer peripheral cover 9 and on the left and right inner sides of the steering case 7 in the direction of rotation from the foremost position of the rotating cutting blade 4 . Since the scattering prevention plate 10 is provided in the front-rear direction and extends down to substantially the same height position, first, the elastic outer peripheral cover 9 prevents dust from scattering forward or sideways from the inside of the cutting blade cover 8. The elastic front cover F prevents clumps of grass clippings, mud, pebbles, etc. from being scattered and discharged forward of the vehicle body 3. It is possible to prevent mud, grass clippings, dust, etc. from scattering outward from the gap, prevent failure of the axle unit U due to adhesion of mud, and prevent scattering from adhering to fruit trees and the like.

According to the second aspect of the invention, a pair of front and rear link arms 11 and 12 are arranged on the left and right, and the upper front ends of the link arms 11 and 12 are pivotally supported on the vehicle body 3 side, and the lower rear ends thereof are pivotally supported on the cutting blade cover 8 side. The link mechanism allows the reaper K to move up and down in a substantially horizontal state. The scattering prevention plate 10 attached to the U side has less vertical movement than that provided on the side of the cutting blade cover 8 that moves up and down. At times, the anti-scattering plate 10 does not get caught on the grass or the ground and can stably prevent the scattering of mud and grass clippings.

According to the third aspect of the invention, since the elastic front cover F and the front end of the anti-scattering plate 10 are spaced apart from each other, the elastic front cover F bends backward due to contact with grass or the ground while the vehicle is traveling forward. Even if it is bent, the scattering prevention plate 10 in the front-rear direction does not hinder the bending or bending of the elastic front cover F due to the gap in front of the scattering prevention plate 10, and the uncut grass of the elastic front cover F can be removed satisfactorily. In addition to being able to maintain the ability to absorb, it is possible to prevent grass clippings and mud from scattering forward.

The perspective view which shows an axle unit and a reaper part. FIG. 3 is a partial cross-sectional view showing a one-side front wheel portion; FIG. 2 is a plan layout diagram showing a wheel transmission mechanism and a scattering prevention structure; The whole side view which shows the raising/lowering of a harvesting device, and a scattering prevention structure.

A seat 15 on which an operator sits is provided at the center of the vehicle body 3, and a reaper K is provided on the lower side of the seat 15, and a reaper K is provided in front of the seat 15 around a pivot axis P in the front-rear direction with respect to the vehicle body 3. An axle unit U attached in a center pivot form capable of swinging left and right, front wheels 1, 1 provided on the left and right sides of the axle unit U, and a handle that can be steered by an operator seated on a seat 15 on the front wheels 1, 1. 16 is provided. A handlebar 16 is supported by a handlebar post 14 and a step 13 is provided between the lower end of the handlebar post 14 and the seat 15 . The handle post 14 is provided with a key switch for starting the prime mover 5, an accelerator lever for manual operation, a traveling change lever, a choke lever, an hour meter, and the like. A prime mover 5 (not shown) is provided behind the seat 15, and the power of the prime mover 5 is transmitted to the reaper K to rotate the cutting blade 4 so that the grass can be mowed. The power of the prime mover 5 is also transmitted to a traveling HST (hydraulic continuously variable transmission) 18 provided below the prime mover 5 to drive the rear wheels 2 through a transmission case 17 . In addition, the hydraulic pressure of the HST 18 drives the front axle unit U through the hydraulic hose 19 so that the vehicle can travel in a four-wheel drive mode. The motor 5 has an output shaft 20 projecting downward, and a cutting blade V-belt 21 for driving the reaping device K and the HST 18 and an engine pulley 23 around which a running V-belt 22 is wound are attached to the output shaft 20. there is The cutting blade V-belt 21 is wound between an engine pulley 23 and a cutting blade pulley 25 attached to the upper end of a blade shaft 24 of the cutting device K, and a tension pulley 26 tensions and loosens the cutting blade V-belt 21. Thus, the power transmission to the cutting blade pulley 25 can be turned on and off. A cutting blade 31 is attached to the lower end of the blade shaft 24 , and the cutting blades 4 are pivotally supported at both ends of the cutting blade 31 .

The reaper K is attached to a pair of front and rear link arms 11 and 12 that are hung from the vehicle body 3. The link arms 11 and 12 are also provided on the left and right sides so that the upper front sides of the link arms 11 and 12 face the vehicle body 3 side. The lower rear side is pivotally supported on the cutting blade cover 8 side of the reaping device K, and the operator vertically operates the elevating lever 27 to raise and lower the reaping device K in a substantially horizontal state via the elevating link mechanism 28 . can be done. With the link mechanism provided with the link arms 11 and 12 on the left and right sides, the reaper K can be raised and lowered while maintaining a substantially horizontal state. At the front end of the reaper K, an elastic outer peripheral cover 9 is provided over the left and right width of the cutting blade cover 8 . The elastic outer cover 9 is made of an elastic material such as rubber or resin. In a plan view, the elastic outer peripheral cover 9 hangs down in a horizontal direction, and the hanging length 9h is set to approximately 1/2 of the side surface height 8h of the cutting blade cover 8. As shown in FIG. The elastic outer peripheral cover 9 hanging down from the upper surface of the cutting blade cover 8 to approximately 1/2 of the height 8h of the side surface of the cutting blade cover 8 can be installed within the cutting blade cover 8 without hindering the performance of raking grass from the front. This prevents dust and the like from being blown up around the cutting blade cover 8, especially forward.

The axle unit U is provided with a hydraulic motor 33 in the central part on the left and right. Output from the hydraulic motor 33 is transmitted from the axle shaft 34 through the gears 35 and 36 in the transmission case 6, from the transmission shaft 37 through the gears 38 and 39. It is transmitted to the wheel shaft 40 and the wheel boss 41 to drive the front wheel 1 . The transmission case 6 at both left and right ends of the axle unit U has a lower fitting portion 6a extending downward. The lower fitting portion 6a is fitted, and the steering case 7 is rotatably supported around the lower fitting portion 6a. The steering case 7 can be operated to steer the front wheels 1, 1 via a steering rod 44 and a connecting rod 48 connecting the left and right steering cases 7, 7 by turning the steering wheel 16 by the operator. It is possible. The transmission case 6, the steering case 7, and the side case 45 are filled with oil. The oil is filled to a level higher than the seal portion of the seal member S because the oil level is at a level where air can escape from the hole (oil level L).

As shown in FIG. 3, most of the grass cut by the cutting blade 4 that rotates clockwise in plan view is discharged from the discharge port 29 at the right rear portion of the cutting blade cover 8 (the front portion of the right rear wheel 2) or behind the cutting blade cover 8. Although it is configured to be discharged from the central portion, some cut grass may be discharged from the front of the cutting-blade cover 8 or from the space 30 between the right front wheel 1 and the cutting-blade cover 8 behind it. The cut grass that scatters and is discharged to the front of the cutting blade cover 8 is shielded by an elastic front cover F that hangs down between the left and right front wheels 1, 1 on the front side of the axle unit U to a position approaching the ground J, and the transmission case of the axle unit U. Mud and grass clippings that scatter in six directions are shielded by a scattering prevention plate 10 attached to the axle unit U side between the elastic outer cover 9 and the elastic front cover F. The anti-scattering plate 10 is made of an elastic material such as rubber or resin, and is attached to the protective cover 47 below the axle unit U in the longitudinal direction. It hangs down to the same height as the elastic front cover F. A gap 32 is provided between the elastic front cover F and the front end of the anti-scattering plate 10 so as not to hinder the rearward bending or bending of the elastic front cover F during mowing work during forward traveling. Further, the anti-scattering plate 10 is provided with an inclination α toward the rear right and outward in plan view, and the lower rear portion is cut upward, so that the anti-scattering plate 10 does not touch the ground J or grass when the vehicle is traveling backward. The lower part of the anti-scattering plate 10 is surely curved outward to the right without being caught, and the anti-scattering of mud and grass clippings can be stably maintained. The link mechanism consisting of the link arms 11 and 12 for elevating the reaper K raises the reaper K while moving backward when it is raised, and moves forward while it is lowered when it is lowered. If a gap is formed between the prevention plate 10 and the elastic outer cover 9, there is a possibility that cut grass, mud, pebbles, etc., may scatter rightward from the gap. Considering the scattering prevention effect, it is preferable that this gap is not formed regardless of the state of the reaping device K. When the front part comes into contact with the anti-scattering plate 10, the anti-scattering plate 10 made of elastic material is deformed, and the anti-scattering effect of grass clippings and mud is not stabilized. The front end portions of the cutting blade cover 8 and the elastic outer peripheral cover 9 do not come into contact with the anti-scattering plate 10 and deform greatly even in the closed position. As shown in FIG. 4, the anti-scattering plate 10 has a shape (a) obtained by cutting the cut shape of the rear lower part into a straight line, a shape (b) cut into a round curve, or a shape (c) cut into a polygonal shape. However, the same effect can be expected.

When grass clippings or mud adhere to the seal member S due to the rotation of the cutting blade 4, they enter between the lower fitting portion 6a of the transmission case 6 and the lip portion inside the seal member S, and mud in particular acts as an abrasive. As a result, the lip portion or the lower fitting portion 6a formed of an aluminum-based casting material wears out in a short time. Since the oil level L in the transmission case 6 is filled to a level higher than that of the seal member S, there is a problem that if the sealing effect of the seal member S weakens, the oil inside leaks. Here, on the front side of the axle unit U, there is provided an elastic front cover F which is suspended between the left and right front wheels 1, 1 and extends down to the vicinity of the ground. An elastic outer peripheral cover 9 is provided at a position substantially along the outer peripheral edge R of the rotation locus of the blade 4 and at the rear part of the front wheels 1, 1, and a steering case on the rotating direction side from the foremost position of the rotating cutting blade 4. 7 and between the elastic front cover F and the elastic outer peripheral cover 9, a scattering prevention plate 10 in the front-rear direction is provided so as to extend down to a position substantially at the same height as the lowest cutting blade 4. It is configured as a lawn mower. FIG. 4 shows the state in which the cutting device K is lowered to the lowest position, and the anti-scattering plate 10 extends down to a position substantially at the same height as the cutting blade 4 . With this configuration, grass clippings and mud scattered by the rotating cutting blade 4 are blocked by the elastic front cover F extending between the front wheels 1, 1, and are prevented from scattering forward of the vehicle body 3. An elastic outer peripheral cover 9 hanging down at a position substantially along the outer peripheral edge R of the rotation trajectory of the blade 4 and at the rear portion of the front wheels 1, 1 removes dirt and dust picked up by the rotation of the cutting blade 4 from the inside of the cutting blade cover 8 to the front. Alternatively, it is possible to suppress scattering discharge to the side. In addition, the cutting blade 4 lowered to the lowest position is located between the elastic front cover F and the elastic outer peripheral cover 9 and between the elastic front cover F and the elastic outer peripheral cover 9 and on the left and right inner sides of the steering case 7 in the direction of rotation from the foremost position of the rotating cutting blade 4 . Since the scattering prevention plate 10 is provided in the front-rear direction and extends down to substantially the same height position, first, the elastic outer peripheral cover 9 suppresses dust from scattering forward or sideways from the cutting blade cover 8, The elastic front cover F prevents clumps of mowed grass, mud, and pebbles from scattering and discharging forward of the vehicle body 3, and the scattering prevention plate 10 in the front-rear direction prevents the right steering case 7 direction and the right front wheel 1 from reaping device K. It is possible to prevent mud, grass clippings, dust, etc. from scattering outward from the spacing portion 30, and also prevent failure of the axle unit U due to adhesion of mud.

A pair of front and rear link arms 11 and 12 are arranged on the left and right sides, and the upper front ends of the link arms 11 and 12 are pivotally supported on the vehicle body 3 side, and the lower rear ends thereof on the cutting blade cover 8 side. can be moved up and down in a substantially horizontal state, and the anti-scattering plate 10 is attached to the lower side of the axle unit U tilted rearward and outward in a plan view. The prevention plate 10 moves up and down less than it is provided on the side of the cutting-blade cover 8 that moves up and down. It does not get caught on the ground or the ground, and a stable effect of preventing scattering of muddy soil and grass clippings can be obtained.

In addition, since the elastic front cover F and the front end of the anti-scattering plate 10 are spaced apart from each other, even if the elastic front cover F is bent or bent backward due to contact with grass or the ground while the vehicle is running forward, it will scatter. Due to the gap 32 on the front side of the prevention plate 10, the scattering prevention plate 10 in the front-rear direction does not hinder the bending or bending of the elastic front cover F, so that the elastic front cover F can maintain a good ability to take in uncut grass. , cut grass can be prevented from jumping forward.

REFERENCE SIGNS LIST 1 front wheel 2 rear wheel 3 vehicle body 4 cutting blade 5 motor 6 transmission case 6a lower fitting portion 7 steering case 8 cutting blade cover 9 elastic outer peripheral cover 10 scattering prevention plate 11 link arm 12 link arm F elastic front cover K reaper R Outer edge of rotation trajectory U Axle unit

Claims (3)

A reaper (K) equipped with a substantially horizontally rotating cutting blade (4) is vertically mounted on the abdomen of a vehicle body (3) on which a pair of left and right front wheels (1) and rear wheels (2), (2) are suspended. A four-wheel drive system that can freely move up and down and can drive the reaper (K), the front wheels (1), (1) and the rear wheels (2), (2) by the prime mover (5) installed at the rear of the vehicle body (3). In this mower, the front wheels (1), (1) are transmitted by an axle unit (U) supported swingably on a vehicle body (3) in the form of a center pivot. A steering case (7) fitted with a sealing member (S) for inserting a lower fitting portion (6a) extending downward from the transmission case (6) is fitted and pivotally supported in the lower fitting portion (6a). An elastic front cover (F) is provided on the front side of the axle unit (U), extending between the left and right front wheels (1), (1) and extending down to the vicinity of the ground to cover the cutting blade (4). ), in a plan view, an elastic outer peripheral cover (9) hanging down at a position substantially along the outer periphery (R) of the rotation locus of the cutting blade (4) and at a position behind the front wheels (1), (1). is provided between the left and right inner sides of the steering case (7) in the direction of rotation from the foremost position of the rotating cutting blade (4) and between the elastic front cover (F) and the elastic outer peripheral cover (9) 1. A lawn mower, characterized in that a front-rear scattering prevention plate (10) is provided so as to extend down to substantially the same height position as the lowest cutting blade (4). A pair of front and rear link arms (11) and (12) are arranged on the left and right, with the upper front ends of the link arms (11) and (12) facing the vehicle body (3) and the lower rear ends facing the blade cover (8). The reaping device (K) is configured to be lifted and lowered in a substantially horizontal state by a pivoting link mechanism, and the anti-scattering plate (10) is tilted rearward and outward in plan view to the lower side of the axle unit (U). 2. The lawn mower according to claim 1, wherein the rear lower portion of the anti-scattering plate (10) is cut upward and rearward. A lawn mower according to claim 1 or 2, wherein the elastic front cover (F) and the front end of the anti-scattering plate (10) are spaced apart from each other.

Images