Grass trimmer

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

[Technical field]

[0001] The present invention relates to a four-wheel drive grass cutter configuration that prevents oil leakage problems from the axle unit between the left and right front wheels and prevents cut grass from scattering from openings behind the front wheels and in front of the cutting device. [Background technology]

[0002] Conventionally, there have been known four-wheel drive grass cutters in which the front wheels are driven by a front axle unit attached to the vehicle body in a center pivot form that can swing left and right around a pivot shaft in the front-rear direction, as shown in Patent Document 1. These axle units adopt a form in which the steering case is fitted and pivoted to a lower fitting portion that extends downward from the transmission case at both left and right ends, and the lower fitting portion of the transmission case is inserted into a seal member such as an oil seal or dust seal attached to the steering case, and is supported by a bearing in the steering case. When the operator performs a steering operation with mud scattered by the rotation of the cutting blade attached to the seal member, the steering case rotates around the axis of the lower fitting portion, the inner lip portion of the seal member and the lower fitting portion slide against each other, and the attached mud acts as an abrasive and the sealing effect of the seal member is lost. In particular, the lower fitting portion of the transmission case made of aluminum-based material wears out in a short time, causing a problem of oil leaking from the steering case. In addition, the front wheels of a four-wheel drive system have a wide operating range when steering, requiring a large distance between them and the harvesting equipment. This makes it easy for cut grass, mud, pebbles, etc. to fly out from this area, damaging the surrounding fruit trees and causing bacteria in the ground or soil to adhere to the fruit and leaves, making the fruit trees more susceptible to disease. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-236675 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a four-wheel drive grass cutter that has a simple and inexpensive configuration, prevents oil leakage problems caused by wear of the seal of the axle unit, and prevents grass clippings, mud, pebbles, etc. from scattering from the gap between the front wheels and the cutting device. [Means for solving the problem]

[0005] The invention described in claim 1 relates to a four-wheel drive grass cutter in which a pair of left and right front wheels 1,1 and rear wheels 2,2 are suspended from a body 3, and a cutting device K equipped with a cutting blade 4 that rotates approximately horizontally is provided so as to be movable up and down. The cutting device K and the front wheels 1,1 and rear wheels 2,2 can be driven by a prime mover 5 provided at the rear of the body 3. The front wheels 1,1 are transmitted to the body 3 by an axle unit U that is supported on the body 3 in a center pivot form so as to be able to swing freely. A steering case 7 is provided with a seal member S attached thereto, through which a lower fitting portion 6a extending downward from a transmission case 6 at both left and right ends of the axle unit U is inserted. An elastic front cover F is provided on the front side of the axle unit U, which is fitted and pivoted to the lower fitting portion 6a and extends downward between the left and right front wheels 1,1 to the vicinity of the ground. An elastic outer periphery cover 9 is provided on the front end of the blade cover 8 covering the blade 4, which is provided at a position that is approximately along the outer periphery R of the rotation path of the blade 4 in a plan view and at a position behind the front wheels 1,1. A front-rear scattering prevention plate 10 is provided on the left and right inner sides of the steering case 7 on the side in the direction of rotation from the front end position of the rotating blade 4, and between the elastic front cover F and the elastic outer periphery cover 9, which is provided with a position that is approximately the same height as the most lowered blade 4. A pair of front and rear link arms 11, 12 for raising and lowering the reaping device K are arranged on the left and right, and a link mechanism is provided in which the upper front ends of the link arms 11, 12 are pivoted to the vehicle body 3 side and the lower rear ends are pivoted to the blade cover 8 side, so that the reaping device K can be raised and lowered while remaining in a substantially horizontal position. The scattering prevention plate 10 is attached to the underside of the axle unit U while being tilted rearward and outward in a plan view, and the rear lower portion of the scattering prevention plate 10 is cut rearward and upward. The grass cutter is configured as follows.

[0006] The invention described in claim 2 is The scattering prevention plate 10 is tilted backward and outward in a plan view. Slanted α The grass cutter is configured as follows.

[0007] Effect of the Invention

[0008] The invention described in claim 1 is a four-wheel drive grass cutter in which a pair of left and right front wheels 1,1 and rear wheels 2,2 are suspended from a body 3 on which a cutting device K equipped with a cutting blade 4 that rotates approximately horizontally is mounted so as to be movable up and down, and a prime mover 5 mounted on the rear of the body 3 drives the cutting device K, the front wheels 1,1 and the rear wheels 2,2. The front wheels 1,1 are transmitted to the axle unit U supported on the body 3 in a center pivot manner so as to be swingable, and a steering case 7 to which a seal member S is attached and through which a lower fitting portion 6a extending downward from a transmission case 6 at both left and right ends of the axle unit U is fitted and pivotally supported by the lower fitting portion 6a, and a steering case 7 is provided on the front side of the axle unit U between the left and right front wheels 1,1. An elastic front cover F is provided which extends down to near the ground over the entire length of the blade cover 8, and an elastic outer peripheral cover 9 is provided at the front end of the blade cover 8 covering the blade 4, which hangs down at a position which, in a plan view, approximately follows the outer circumferential edge R of the rotational path of the blade 4 and at a position rear of the front wheels 1,1.Therefore, grass clippings and mud scattered by the rotating blade 4 are blocked by the elastic front cover F which extends between the front wheels 1,1 and are not scattered forward of the vehicle body 3, and the elastic outer peripheral cover 9 which hangs down at a position which approximately follows the outer circumferential edge R of the rotational path of the blade 4 at the front end of the blade cover 8 and at a position rear of the front wheels 1,1 can prevent dirt and dust stirred up by the rotation of the blade 4 from being discharged forward or sideways from within the blade cover 8. In addition, a front-to-rear scattering prevention plate 10 is provided on the left and right inner sides of the steering case 7 in the direction of rotation from the front end position of the rotating blade 4, and between the elastic front cover F and the elastic outer peripheral cover 9, and extends downward to a position approximately the same height as the lowered cutting blade 4.Therefore, the elastic outer peripheral cover 9 first prevents dirt and dust from being scattered forward or to the side from inside the cutting blade cover 8, and the elastic front cover F prevents clumps of grass clippings, mud, pebbles, etc. from being scattered forward of the body 3. The front-to-rear scattering prevention plate 10 prevents mud, grass clippings, dirt, etc. from being scattered outward in the direction of the steering case 7 or from the gap between the front wheel 1 and the cutting device K, which prevents failure of the axle unit U due to mud adhesion and also prevents scattered material from adhering to fruit trees, etc.

[0009] Furthermore, the reaping device K is raised and lowered. A link mechanism in which a pair of front and rear link arms 11, 12 are arranged on the left and right sides, and the upper front ends of the link arms 11, 12 are pivotally supported on the vehicle body 3 side and the lower rear ends are pivotally supported on the blade cover 8 side. To set up Due to Applicable The mowing device K is configured to be raised and lowered while remaining in a substantially horizontal state, and the anti-scattering plate 10 is attached to the underside of the axle unit U, so that the anti-scattering plate 10 attached to the axle unit U side moves up and down less than if it were provided on the side of the cutting blade cover 8, which rises and falls, and the rear lower part of the anti-scattering plate 10 is cut toward the rear and upward, so that the anti-scattering plate 10 does not get caught on grass or the ground when traveling backward, and can stably prevent mud and cut grass from scattering.

[0010] Claim 2 The invention described in The scattering prevention plate 10 is provided with an inclination α toward the rear and outward in a plan view, so that the lower part of the scattering prevention plate 10 surely curves outward during backward travel, and scattering prevention of mud and grass clippings can be stably maintained. [Brief description of the drawings]

[0011] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 4 is a plan view showing the wheel transmission mechanism and the anti-scattering configuration. [Figure 4] FIG. 4 is an overall side view showing the lifting and scattering prevention structure of the harvesting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A seat 15 on which an operator sits is provided in the center of the vehicle body 3, and a mower K that can be raised and lowered is provided on the lower side of the seat 15. In front of the seat 15, an axle unit U is attached to the vehicle body 3 in a center pivot form that can swing left and right about a pivot axis P in the fore-and-aft direction, front wheels 1,1 are provided on the left and right of the axle unit U, and a handlebar 16 is provided that allows the operator seated on the seat 15 to steer the front wheels 1,1. The 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 handlebar post 14 is provided with a key switch for starting the motor 5, an accelerator lever for manual operation, a travel change lever, a choke lever, an hour meter, etc. (not shown). The motor 5 is provided behind the seat 15, and the power of the motor 5 is transmitted to the mower K to rotate the cutting blade 4 to mow grass. The power of the prime mover 5 is also transmitted to a hydraulic continuously variable transmission (HST) 18 for traveling provided below the prime mover 5, and drives the rear wheels 2, 2 via a transmission case 17. The hydraulic pressure of the HST 18 drives a front axle unit U through a hydraulic hose 19, enabling the vehicle to travel in four-wheel drive mode. The prime mover 5 has an output shaft 20 protruding downward, and attached to the output shaft 20 is an engine pulley 23 around which a blade V-belt 21 for driving the mower K and the HST 18 and a traveling V-belt 22 are wound. The blade V-belt 21 is wound between the engine pulley 23 and a blade pulley 25 attached to the upper end of a blade shaft 24 of the mower K, and the power transmission to the blade pulley 25 can be turned on and off by tensioning or loosening the blade V-belt 21 with a tension pulley 26. A cutting blade 31 is attached to the lower end of the blade shaft 24, and the cutting blade 4 is pivotally supported on both ends of the cutting blade 31.

[0013] The mowing device K is attached to a pair of front and rear link arms 11, 12 suspended from the vehicle body 3, and the link arms 11, 12 are also provided on the left and right, with the upper front sides of the link arms 11, 12 pivoted to the vehicle body 3 and the lower rear sides pivoted to the cutting blade cover 8 of the mowing device K, and the operator can raise and lower the mowing device K in a substantially horizontal state via a lifting link mechanism 28 by operating a lifting lever 27 up and down. The link mechanism with the link arms 11, 12 provided on the left and right allows the mowing device K to be raised and lowered while maintaining a substantially horizontal state. An elastic outer periphery cover 9 is provided at the front end of the mowing device K across the left and right width of the cutting blade cover 8. This elastic outer periphery cover 9 is formed from an elastic material such as rubber or resin, and hangs down in a position generally along the outer periphery R of the rotation trajectory of the blade 4 in a plan view at the left-right center portion, and hangs down horizontally at the rear portion of the front wheels 1,1 in a plan view, with the hanging length 9h set to approximately 1 / 2 the side height 8h of the blade cover 8. This elastic outer periphery cover 9, which hangs down from the top surface of the blade cover 8 to approximately 1 / 2 the side height 8h of the blade cover 8, does not impede the grass raking performance from the front, and prevents dirt and the like that fly up inside the blade cover 8 from being released to the periphery of the blade cover 8, particularly in the forward direction.

[0014] The axle unit U is provided with a hydraulic motor 33 at the center on the left and right, and the output from the hydraulic motor 33 is transmitted from the axle shaft 34 through a gear 35, a gear 36, a transmission shaft 37, a gear 38, and a gear 39 in the transmission case 6 to a wheel shaft 40 and a wheel boss 41 to drive the front wheels 1. The transmission cases 6 at both left and right ends of the axle unit U form lower fitting parts 6a extending downward, and the lower fitting parts 6a are fitted into a seal member S and a bearing 42 at the upper end of the steering case 7 and a bearing 43 at the lower end, and the steering case 7 is supported rotatably around the lower fitting parts 6a. The steering case 7 allows the driver to steer the front wheels 1, 1 via a steering rod 44 and a connecting rod 48 that connects the left and right steering cases 7, 7 by turning the handlebars 16. The inside of the transmission case 6, steering case 7, and side case 45 are filled with oil, and this oil is connected to the operating oil path of the HST 18. The oil level is up to a level where air can escape from the hole for the air bleed bolt 46 at the top end of the steering case 7 (oil level L), which means that the oil is filled to a level higher than the sealing portion of the sealing member S.

[0015] 3, most of the grass cut by the blade 4 rotating to the right in a plan view is discharged from an outlet 29 at the rear right side of the blade cover 8 (forward of the right rear wheel 2) or from the rear center of the blade cover 8, but some grass clippings may be discharged from the front of the blade cover 8 or from a gap 30 between the right front wheel 1 and the blade cover 8 behind it. Grass clippings scattered and discharged in front of the blade cover 8 are blocked by an elastic front cover F that hangs down to a position approaching the ground J and spans between the left and right front wheels 1,1 on the front side of the axle unit U, and mud and grass clippings scattered in the direction of the transmission case 6 of the axle unit U are blocked by a scattering prevention plate 10 attached to the axle unit U side between the elastic outer periphery cover 9 and the elastic front cover F. The scattering prevention plate 10 is made of an elastic material such as rubber or resin, and is attached to the protective cover 47 on the underside of the axle unit U in the front-rear direction, and hangs down to a height approximately equal to that of the lowered cutting blade 4 and the elastic front cover F. A gap 32 is provided between the elastic front cover F and the front end of the scattering prevention plate 10 so as not to hinder the elastic front cover F from bending or curving backward during grass cutting work while traveling forward. Furthermore, the scattering prevention plate 10 is provided with an inclination α toward the rear right and outward in a plan view, and the rear lower part is cut toward the rear and upward, so that the scattering prevention plate 10 does not get caught on the ground J or grass during backward traveling, and the lower part of the scattering prevention plate 10 is surely curved toward the right and outward during backward traveling, and the scattering prevention of mud and grass clippings can be stably maintained. The link mechanism consisting of link arms 11, 12 that raise and lower the cutting device K moves backward when raising the cutting device K and moves forward when lowering the cutting device K, so if a gap is formed between the scattering prevention plate 10 and the elastic outer peripheral cover 9, grass clippings, mud, pebbles, etc. may scatter to the right side from the gap. Considering the scattering prevention effect, it is preferable that no gap is formed regardless of the state of the cutting device K. However, if the front end of the cutting blade cover 8 or the front part of the elastic outer peripheral cover 9 contacts the scattering prevention plate 10 when the cutting device K is in the lowest position, the scattering prevention plate 10 made of elastic material will deform, and the scattering prevention effect of the cutting grass clippings and mud will not be stable. Therefore, the cutting device K is configured so that the front end of the cutting blade cover 8 or the front end of the elastic outer peripheral cover 9 will not contact the scattering prevention plate 10 and cause significant deformation even when the cutting device K is in the lowest position, i.e., when the cutting device K is moved to the most forward position.Furthermore, as shown in Figure 4, the same effect can be expected even if the cut shape of the lower rear part of the shatterproof plate 10 is cut in a straight line (a), a curved, rounded shape (b), or a polygonal shape (c).

[0016] When grass clippings or mud adhere to the seal member S due to the rotation of the cutting blade 4, they get in between the lower fitting portion 6a of the transmission case 6 and the lip portion inside the seal member S, and the mud in particular acts as an abrasive, causing wear in a short period of time to the lip portion or the lower fitting portion 6a, which is made of an aluminum-based casting material. Because the oil level L inside the transmission case 6 is filled to a level higher than the seal member S, there is a problem that if the sealing effect of the seal member S weakens, the oil inside will leak. In this grass cutter, an elastic front cover F is provided on the front side of the axle unit U, extending downward to the vicinity of the ground between the left and right front wheels 1,1, an elastic outer periphery cover 9 is provided on the front end of the blade cover 8 covering the blade 4, in a plan view, at a position substantially along the outer periphery R of the rotation trajectory of the blade 4 and at a position rearward of the front wheels 1,1, and a scattering prevention plate 10 is provided on the left and right inner sides of the steering case 7 on the side in the direction of rotation from the front end position of the rotating blade 4, and between the elastic front cover F and the elastic outer periphery cover 9, extending downward to a position substantially the same height as the lowered blade 4. Fig. 4 shows the state in which the cutting device K is lowered to the lowermost position, and the scattering prevention plate 10 is provided extending downward to a position substantially the same height as the blade 4. With this configuration, grass clippings and mud scattered by the rotating blade 4 are blocked by the elastic front cover F spanning between the front wheels 1,1, and are not scattered forward of the vehicle body 3, and the elastic outer peripheral cover 9 that hangs down from the front end of the blade cover 8 in a position that roughly follows the outer peripheral edge R of the rotational trajectory of the blade 4, and at a position rearward of the front wheels 1,1, prevents dirt stirred up by the rotation of the blade 4 from being scattered forward or to the side from within the blade cover 8. In addition, a front-to-rear scattering prevention plate 10 is provided on the left and right inner sides of the steering case 7 in the direction of rotation from the front end position of the rotating blade 4, and between the elastic front cover F and the elastic outer peripheral cover 9, and extends downward to a position approximately the same height as the lowest lowered cutting blade 4.Therefore, the elastic outer peripheral cover 9 first prevents dirt and dust from being scattered forward or to the side from the cutting blade cover 8, and the elastic front cover F prevents clumps of grass clippings, mud and pebbles from being scattered forward of the vehicle body 3. The front-to-rear scattering prevention plate 10 prevents mud, grass clippings, dust and the like from being scattered toward the right steering case 7 or outward from the gap 30 between the right front wheel 1 and the cutting device K, and also prevents failure of the axle unit U due to mud adhesion.

[0017] In addition, a pair of front and rear link arms 11, 12 are arranged on the left and right sides, and the upper front ends of the link arms 11, 12 are pivoted to the vehicle body 3 side and the lower rear ends are pivoted to the blade cover 8 side by a link mechanism, which is configured to allow the cutting device K to be raised and lowered while remaining in an approximately horizontal position.The scattering prevention plate 10 is attached to the underside of the axle unit U, which is tilted rearward and outward in a plan view, so that the scattering prevention plate 10 attached to the axle unit U side moves up and down less than if it were attached to the blade cover 8 side, which rises and falls.In addition, the rear lower part of the scattering prevention plate 10 is cut rearward and upward, so that the scattering prevention plate 10 does not get caught on grass or the ground when traveling in reverse, and a stable effect of preventing mud and clippings from scattering is obtained.

[0018] Furthermore, since the elastic front cover F and the front end of the scattering prevention plate 10 are positioned at a distance from each other, even if the elastic front cover F curves or bends backwards due to contact with grass or the ground while moving forward, the gap 32 on the front side of the scattering prevention plate 10 does not prevent the scattering prevention plate 10 from hindering the curving or bending of the elastic front cover F in the front-to-rear direction, thereby maintaining the elastic front cover F's ability to capture uncut grass while preventing cut grass from flying forward. [Explanation of symbols]

[0019] 1 Front wheel 2 Rear wheels 3. Body 4 cutting blade 5. Prime Mover 6 Transmission case 6a Lower fitting part 7 Steering case 8 Blade cover 9 Elastic outer cover 10 Shatterproof plate 11 Link arm 12 Link arm F Elastic front cover K Reaping device R Rotation trajectory outer edge U Axle Unit α slope

Claims

1. A mower (K) having a cutting blade (4) that rotates approximately horizontally is provided on the underside of a vehicle body (3) that suspends a pair of left and right front wheels (1), (1) and rear wheels (2), (2) so as to be movable up and down, and the mower (K) and the front wheels (1), (1) and rear wheels (2), (2) are driven by a prime mover (5) provided at the rear of the vehicle body (3). In this four-wheel drive grass cutter, the front wheels (1), (1) are supported by an axle unit that is swingably supported on the vehicle body (3) in a center pivot configuration. A steering case (7) is fitted with a seal member (S) for inserting a lower fitting portion (6a) extending downward from a transmission case (6) at both left and right ends of the axle unit (U) and is pivotally supported by the lower fitting portion (6a). An elastic front cover (F) is provided on the front side of the axle unit (U) and extends downward to the vicinity of the ground between the left and right front wheels (1, 1). A blade cover (8) for covering the blade (4) has a front end portion having a seal member (S) for inserting a lower fitting portion (6a) extending downward from the transmission case (6) at both left and right ends of the axle unit (U) and is pivotally supported by the lower fitting portion (6a). An elastic outer circumferential cover (9) is provided at a position approximately along the outer circumferential edge (R) of the rotation trajectory of the front wheel (1), (4), and at a rear portion of the front wheel (1), (1), and a front-rear scattering prevention plate (10) is provided on the left and right inner sides of the steering case (7) on the side in the direction of rotation from the front end position of the rotating cutting blade (4) and between the elastic front cover (F) and the elastic outer circumferential cover (9) to a position approximately the same height as the lowered cutting blade (4), and before raising and lowering the cutting device (K), A pair of rear link arms (11, 12) are arranged on the left and right, and a link mechanism is provided in which the upper front ends of the link arms (11, 12) are pivotally supported on the vehicle body (3) side and the lower rear ends are pivotally supported on the blade cover (8) side, thereby enabling the cutting device (K) to be raised and lowered while remaining in a substantially horizontal position, and a scattering prevention plate (10) is attached to the underside of the axle unit (U) and the rear lower portion of the scattering prevention plate (10) is cut toward the rear and upward.

2. 2. The grass cutter according to claim 1, wherein the scattering prevention plate (10) is inclined (α) rearward and outward in a plan view.

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