JP6307414B2 - Belt-driven reel lawn mower - Google Patents

Description

  The present invention relates to a reel-type lawn mower having a reel-type mowing unit, and more particularly to a belt-driven reel-type lawn mower that transmits engine output to a mowing unit via a power transmission belt.

  For example, in a reel-type riding lawn mower, it is necessary to transmit power to a plurality of reel-type mowing units located at positions away from the front and rear of the engine mounting position. Therefore, after the rotation of the engine output shaft is transmitted to the reel rotation main shaft via the belt / pulley transmission mechanism, the rotation of the engine output shaft is further separated back and forth via the belt / pulley transmission mechanism. It is transmitted to the reel shaft of each cutting unit in position.

  In such a belt-driven reel-type lawn mower, the rotation direction cannot be switched between forward and reverse by switching the hydraulic pressure as in the case of the hydraulic drive type, and the rotation direction of each reel-type mowing unit depends on the engine output shaft. The rotation direction is the same. Further, the rotational speed of the mowing unit also increases or decreases according to the rotational speed of the engine output shaft.

  In the polishing operation of the reel of the reaping unit, it is necessary to reversely rotate the reel while applying an abrasive to the reel. The rotational speed of the cutting unit in the polishing operation is about one-tenth of the rotational speed of the cutting operation. In a conventional belt-driven reel lawn mower, the reel rotates only in the same direction as the rotation direction of the engine output shaft. Therefore, a lapping machine for reversely rotating the reel is attached to the reel in order to polish the reel.

  Further, in the lawn mowing work, the lawn mowing is performed by rotating the reel of the mowing unit at the corresponding rotational speed in the state of running speed at a predetermined engine speed. Here, in the mowing unit, the turf is mowed by rotating a reel having a plurality of spiral reel blades and sandwiching and cutting the turf between the straight fixed blades. The distance that the machine moves forward after one reel blade starts cutting the lawn until the next reel blade starts cutting is called the “cutting pitch”. When it is determined that the cutting pitch by the reel is too wide, the cutting pitch is narrowed by reducing the traveling speed while maintaining the engine speed. For example, in a riding lawn mower, a speed change mechanism for a vehicle speed is configured by HST, and a cutting speed is reduced by operating a travel shift pedal for advancing HST to lower a travel speed.

  Here, in the walking-type lawn mower described in Patent Document 1, the power from the engine is branched and transmitted to the drum wheel and the reel cutter, so that the running speed and the cutting pitch can be changed independently from the engine. A transmission mechanism is arranged in a gear-type power transmission path that transmits rotational force to the reel cutter.

JP 2010-57446 A

In a belt-driven reel-type lawn mower equipped with a belt-pulley type transmission mechanism for transmitting the rotation of the engine output shaft to the front and rear or left and right reel type mowing units, Or the mechanism which can be transmitted to a right and left mowing unit is not proposed.

  For this reason, in the polishing operation of the reels of each mowing unit in this type of lawn mower, in order to reversely rotate the reels, it is necessary to attach and detach the lapping machine, and there is a problem that the efficiency of the polishing operation is poor. . Further, the lapping machine is electrically operated, and there is a restriction that the polishing operation cannot be performed without a power supply facility. Furthermore, when polishing the left and right or front and rear mowing units, it is necessary to attach a wrapping machine to each mowing unit. Therefore, when the number of wrapping machines is small, the work efficiency is reduced. is there.

  On the other hand, in the belt-driven reel lawn mower equipped with a belt / pulley type transmission mechanism for transmitting the rotation of the engine output shaft to the front and rear or left and right reel type mowing units, the rotational speed of the engine output rotation is increased and decreased. No mechanism has been proposed that can be transferred to each mowing unit. For this reason, when it is desired to reduce the mowing pitch, it is necessary to adjust by reducing the traveling speed, so that the efficiency of mowing the turf is lowered. The travel speed is adjusted by adjusting the operation amount of an operation member such as a vehicle speed transmission mechanism, for example, a travel shift pedal of HST. If the operation amount cannot be kept constant, the cutting pitch cannot be kept constant.

  An object of the present invention is to provide a belt-driven reel lawn mower that can reversely rotate a reel type mowing unit.

  Another object of the present invention is to provide a belt-driven reel-type lawn mower capable of switching the rotational speed of a reel-type mowing unit between high and low without switching the engine output rotational speed.

  Furthermore, an object of the present invention is to provide a belt-driven reel-type lawn mower capable of selectively attaching a forward / reverse rotation switching mechanism and a rotation speed switching mechanism of a reel-type mowing unit as required. is there.

In order to solve the above-described problems, the present invention transmits the rotation of the engine output shaft to the reel rotation main shaft via the first belt-pulley transmission mechanism, and the rotation of the reel rotation main shaft is A belt-driven reel-type lawn mower that transmits to a reel shaft of a reel-type mowing unit via a belt-pulley-type transmission mechanism of No. 2, wherein the pulley output rotation of the first belt-pulley type transmission mechanism is A gear box for transmitting to the reel rotation spindle; The gear box has a first transmission gear train capable of transmitting the pulley output rotation to the reel rotation main shaft by decelerating the pulley output rotation at a first reduction ratio with the same rotation direction, and the pulley output rotation. The second transmission gear train that can be reversely rotated and decelerated at the second reduction ratio and transmitted to the reel rotation spindle, and the transmission path for the pulley output rotation are connected to the first transmission gear train. And a switching mechanism for switching to one of the second transmission gear trains, and the gear box is second from the first position with respect to the gear box mounting portion provided on the lawn mower body frame. The first position is a position at which the gear box can transmit the pulley output rotation to the reel rotation main shaft, and the second position is at the gear box. The first bell A gap that is separated from the pulley-type transmission mechanism and the reel rotation main shaft so that the belt of the second belt-pulley transmission mechanism can be taken out between the gear box and the shaft end of the reel rotation main shaft. Is the position where is formed.

In the present invention, when the transmission path of the pulley output rotation is switched to the first transmission gear train by the gear box switching mechanism, the pulley output rotation is decelerated at the first reduction ratio while the rotation direction remains the same, and the mowing unit Is transmitted to the other side. Thus, the lawn mowing operation can be performed by rotating the reel of the mowing unit forward at a high speed suitable for mowing. When the transmission path of the pulley output rotation is switched to the second transmission gear train by the switching mechanism, the pulley output rotation is decelerated at the second reduction ratio by the reverse rotation direction and transmitted to the cutting unit side. . Thus, the reel can be polished by rotating the reel of the cutting unit in reverse at a low speed suitable for polishing.

Therefore, in the reel polishing operation, the operation of loosening the belt of the belt-pulley type transmission mechanism to separate the transmission path and the operation of attaching the wrapping machine to reversely rotate the reel become unnecessary. For this reason, the polishing operation of the reel can be performed only with the lawn mower, and can be performed efficiently without selecting equipment and place. Further, in the belt-driven reel-type lawn mower, the belt, which is a constituent element of the belt-pulley type transmission mechanism, is worn, so that the replacement work is more frequent than other components. In order to make it easy to perform belt replacement work, maintenance inspection work, etc., in the present invention, the gear box has a first position relative to the gear box mounting portion provided on the lawn mower body frame. To the second position so as to be movable. The first position is a position at which the gear box can transmit the pulley output rotation to the reel rotation main shaft. On the other hand, in the second position, the gear box is separated from the first belt-pulley transmission mechanism and the reel rotation main shaft, and the gear box and the shaft end of the reel rotation main shaft are separated from each other. A gap is formed between the first and second belt / pulley transmission mechanisms so that the belt can be taken out. If it does in this way, at the time of belt exchange etc., it is only necessary to move from the 1st position to the 2nd position, without removing a gear box from a gear box attaching part. By
Thus, belt replacement and maintenance inspection can be performed efficiently.

  In the belt-driven reel-type lawn mower of the present invention, as the gear box, instead of the second transmission gear train, the pulley output rotation is the same as the first reduction ratio while the rotation direction remains the same. It is possible to use a gear having a third transmission gear train that can be transmitted to the reel rotation spindle after being reduced by a third reduction ratio that can be reduced to a smaller speed. In this case, the switching mechanism is configured to switch the transmission path of the pulley output rotation to one of the first transmission gear train and the third transmission gear train.

  In this way, when the transmission path of the pulley output rotation is switched to the first transmission gear train by the gear box switching mechanism, the pulley output rotation is decelerated at the first reduction ratio with the same rotation direction. It is transmitted to the mowing unit side. As a result, the lawn mowing operation can be performed at the standard mowing pitch by rotating the reel of the mowing unit forward at the “standard speed” defined by the first reduction ratio. When the transmission path of the pulley output rotation is switched to the third transmission gear train by the switching mechanism, the pulley output rotation has the same rotational direction, but is reduced to a smaller speed than in the case of the reduction by the first reduction ratio, and is cut. It is transmitted to the unit side. As a result, the reel of the reaping unit can be rotated forward at a speed defined by the third reduction ratio that is “higher” than “standard speed”. Thereby, the grass cutting operation can be performed at a cutting pitch narrower than the standard cutting pitch while maintaining the traveling speed.

  Therefore, the grass cutting operation can be performed with a wide and narrow cutting pitch without changing the traveling speed. For example, since it is not necessary to reduce the traveling speed in order to narrow the cutting pitch, it is possible to increase the working efficiency of the grass cutting operation. In addition, in order to adjust the cutting pitch, the amount of cutting of the operating member such as a traveling speed change pedal of a vehicle speed transmission mechanism such as HST is adjusted to increase or decrease the traveling speed to change the cutting pitch. It can be maintained in a certain state.

  Here, if necessary, either a forward / reverse rotation switching gear box or a forward rotation speed switching gear box may be attached. In this case, both of these gear boxes may be detachably attached to a common gear box attachment portion provided on the lawn mower body frame.

  In this case, it is desirable that the gear box be removable from the gear box mounting portion in the second position.

  Here, in order to allow the gear box to slide and move from the first position to the second position, the lawn mower is mounted on the gear box mounting portion while extending in a sliding direction parallel to the reel rotation spindle. A guide shaft attached to the machine body frame may be disposed so that the gear box can be slid along the guide shaft from the first position to the second position. The gear box has a guide shaft hole extending in the sliding direction so that the guide shaft is slidable, and an output pulley shaft of the first belt-pulley type transmission mechanism in the sliding direction. An input side shaft hole inserted from the first position side along the shaft side and an output side shaft into which the shaft end portion of the reel rotation main shaft is inserted from the first position side along the sliding direction. What is necessary is just to arrange a hole.

  In this way, by sliding the gear box, the gear box can be switched to a position where the gear box can be connected to the first belt / pulley transmission mechanism and the reel rotation main shaft and a position where the connection is released. it can. In addition, after the gear box is slid to the second position, the gear box can be removed from the body frame by removing the guide shaft from the gear box mounting portion. Therefore, it is possible to easily attach / detach or replace the gear box.

  INDUSTRIAL APPLICABILITY The present invention can be used for a belt-driven reel riding lawn mower in which a mowing unit is mounted at a position separated from the front and rear. For example, a belt-driven reel-type riding lawn mower includes a front wheel and a rear wheel, left and right reel-type mowing units located in front of the front wheels, and a central reel-type mowing unit located behind the front wheels. And a power transmission mechanism for transmitting the rotation of the engine output shaft to the front wheels.

  The “belt / pulley transmission mechanism” in the present invention is used in a broad sense including a transmission mechanism including a toothed belt and a sprocket, and does not exclude such a transmission mechanism.

FIG. 1 is a plan view, a left side view, and a front view showing a belt-driven reel riding lawn mower according to an embodiment of the present invention. FIG. 3 is an explanatory diagram when a part of a power transmission mechanism of the belt-driven reel type lawn mower of FIG. 1 is taken out and viewed from the left side, an explanatory diagram when viewed from the front, and an explanatory diagram when viewed from above. is there. 2 is a left side view, a right side view, a cross-sectional view of a portion cut along the line AA, and a portion cut along the line BB of the gear box for switching between forward and reverse rotations arranged in the power transmission mechanism of FIG. It is sectional drawing. It is explanatory drawing which shows the state attached to the gear box attachment part provided in the body frame, and the state made to slide, respectively. FIG. 4 is a left side view showing a gear box for switching between positive rotation speeds that can be attached instead of the gear box of FIG. 3, and a cross-sectional view of a portion cut along line CC.

Embodiments of a belt-driven reel lawn mower to which the present invention is applied will be described below with reference to the drawings. In the following embodiments, the present invention is applied to a belt-driven reel-type riding lawn mower provided with right and left mowing units arranged in front of the fuselage and a central mowing unit arranged in the lower center of the fuselage. The present invention relates to a belt-driven reel-type lawn mower provided with more than three mowing units, a belt-driven reel-type lawn mower provided with a single mowing unit, and a belt-driven type other than a riding lawn mower. It can also be applied to a reel type lawn mower.

(overall structure)
FIGS. 1A, 1B and 1C are a plan view, a left side view and a front view showing a riding belt drive type reel lawn mower according to the present embodiment. A belt-driven reel-type riding lawn mower 1 (hereinafter simply referred to as “lawn mower 1”) includes a traveling machine body 2 and reel-type left mowing units 3L mounted on the left and right sides of the front side of the traveling machine body 2. It has a right cutting unit 3R and a reel type central cutting unit 4 mounted on the lower center of the traveling machine body 2. The traveling machine body 2 includes a machine body frame 5, left and right drive wheels 6 </ b> L and 6 </ b> R attached to the front side thereof, and a steering wheel 7 attached to the center of the rear side.

  An engine 9 is mounted on a front portion of the body frame 5 in a state of being covered with a front cover 8. A power transmission mechanism (not shown) that transmits the output rotation of the engine 9 to the left and right drive wheels 6L, 6R by the front cover 8, the left and right fenders 10L, 10R, etc., and the left trimming unit 3L, the right trimming unit A power transmission mechanism, which will be described later, that transmits to 3R, the central cutting unit 4 and the like is also covered. In this example, a hydraulic drive mechanism is employed as a drive mechanism of the traveling system for driving the drive wheels 6L and 6R, and a general HST is mounted as the vehicle speed transmission mechanism. The rear part of the front cover 8 in the body frame 5 is provided with operation members such as a steering handle 11, an accelerator lever 12, a clutch lever (cutter rotation lever) 13, a starter switch 14, a choke knob 15, and a cutter lifting lever 16. The operation unit is arranged, and a seat 17 is arranged on the rear side. A fuel tank 18 and a hydraulic oil tank 19 are mounted on the rear end of the body frame 5 on the rear side of the seat. Further, on the front right side of the seat 17, an operation member of a speed change mechanism for vehicle speed, in this example, a forward travel shift pedal 20F and a reverse travel shift pedal 20R, which are HST speed change operation members, are arranged.

  The central cutting unit 4 is mounted on the rear side of the drive wheels 6L and 6R on the lower side of the body frame 5. The central mowing unit 4 includes a front roller 21 disposed at a front part of the machine body and a rear roller 22 disposed at a rear part of the machine body, and a reel-type cutting blade 23 is disposed therebetween. . The reel-type cutting blade 23 includes a reel 25 (rotating blade) that rotates about a reel shaft (center reel shaft) 24 and a fixed blade 26. The cutting height by the cutting blade 23 is set by adjusting the height position of the front roller 21 or the rear roller 22 or both. A bucket 27 for collecting the cut grass is attached to the rear side of the cutting blade 23 in a detachable state.

  The left mowing unit 3L and the right mowing unit 3R positioned in front of the traveling machine body 2 are swingably attached to outer end portions of left and right lift arms 31L and 31R extending in the machine body width direction. The inner ends of the left and right lift arms 31L and 31R are supported in a swingable manner by the front end portions of the left and right front arms 32L and 32R that extend horizontally forward from the central portion of the front end of the body frame 5. .

The left mowing unit 3L and the right mowing unit 3R are units having a symmetrical structure, and the basic configuration is the same as that of the central mowing unit 4. The left mowing unit 3L includes a front roller 33 disposed at a front part of the machine body and a rear roller 34 disposed at a rear part of the machine body, and a reel-type cutting blade 35 is disposed therebetween. The reel type cutting blade 35 includes a reel 37 that rotates about a reel shaft 36 and a fixed blade 38. The cutting height by the cutting blade 35 is set by adjusting the height position of the front roller 33 or the rear roller 34 or both. A bucket 39 for collecting the cut grass is attached to the front side of the cutting blade 35 in a detachable state. Since the other right mowing unit 3R is the same, the description thereof is omitted. In order to distinguish the left and right reel shafts, in the following description, the reel shaft of the left trimming unit 3L is referred to as the left reel shaft 36L, and the reel shaft of the right trimming unit 3R is referred to as the right reel shaft 36R.

(Power transmission mechanism)
FIG. 2 is an explanatory view showing the power transmission mechanism for transmitting the output of the engine 9 to each drive part. 2A is an explanatory diagram when the engine and the power transmission mechanism are viewed from the left side of the body, FIG. 2B is an explanatory diagram when the part is viewed from the front, and FIG. It is explanatory drawing at the time of seeing the said part from upper direction.

  The engine 9 is, for example, a multi-cylinder gasoline engine, and is mounted horizontally on the front portion of the body frame 5, and the engine output shaft 41 extends horizontally in the body width direction. The rotation of the engine output shaft 41 is transmitted to the reel rotation main shaft 44 via a first belt / pulley transmission mechanism 42 extending downward from the fuselage and the gear box 43. Further, the rotation of the reel rotation main shaft 44 is caused by the left trimming unit 3L and the right trimming via a pair of left and right front belt / pulley transmission mechanisms 45L and 45R (second belt / pulley transmission mechanism) extending forward of the machine body. The central reel of the central cutting unit 4 is transmitted to the left reel shaft 36L and the right reel shaft 36R of the unit 3R, and the rear belt / pulley transmission mechanism 46 (second belt / pulley transmission mechanism) extending rearward of the machine body. It is transmitted to the shaft 24.

  In this example, a first belt-pulley transmission mechanism 42 and a gear box 43 are disposed between the engine 9 and the left drive wheel 6L. The reel rotation main shaft 44 extends horizontally in the body width direction at a position almost directly below the engine output shaft 41 in the body frame 5. Further, it is supported by bearings 47a and 47b attached to the machine body frame 5 so as to be rotatable around its axis.

  The first belt-pulley type transmission mechanism 42 includes an engine-side pulley 51 that is coaxially fixed to the left shaft end portion of the engine output shaft 41, and a gear box-side input that is coaxially fixed to the shaft end portion of the output-side pulley shaft 52. A pulley 53 and two V-belts 54 spanned between the engine-side pulley 51 and the gear box-side input pulley 53 are provided. A pulley output rotation transmitted through the first belt-pulley transmission mechanism 42 is transmitted to the output pulley shaft 52, and the rotation is input to a gear-type power transmission path in the gear box 43 from here. .

  The pair of left and right front belt / pulley transmission mechanisms 45L and 45R for transmitting the rotation from the reel rotation main shaft 44 to the front left reel shaft 36L and the right reel shaft 36R are symmetrically configured. The left front belt-pulley type transmission mechanism 45L has a left main shaft side pulley 55L coaxially fixed to the left shaft end portion of the reel rotation main shaft 44, and a left fixed coaxially to the inner shaft end portion of the left reel shaft 36L. A reel shaft side pulley 56L and a left V-belt 57L bridged between the left main shaft side pulley 55L and the left reel shaft side pulley 56L are provided. The right front belt-pulley transmission mechanism 45R has the same configuration, and is coaxial with the right main shaft side pulley 55R fixed coaxially to the right shaft end portion of the reel rotation main shaft 44 and the inner shaft end portion of the right reel shaft 36R. A right reel shaft side pulley 56R fixed to the right reel shaft side pulley 56R and a right V shaft 57R bridged between the right main shaft side pulley 55R and the right reel shaft side pulley 56R.

Here, as shown in FIG. 2A, by pulling the clutch lever 13 upward from the cut position 13A to the entering position 13B tilted backward, the engine output rotation is moved to the reel rotation main shaft 44 side. Communicated. In other words, the first belt / pulley transmission mechanism 42 that constitutes the power transmission path between the engine output shaft 41 and the gear box 43 has a tension roller 58 that can be swung back and forth by operating the clutch lever 13. Has been placed. When the clutch lever 13 is pulled to the entering position 13B, the tension roller 58 turns to the position where the V belt 54 is pressed through the link mechanism 59 as shown in the figure. As a result, the V-belt 54 is held in a predetermined stretched state, and the engine rotation can be transmitted.

(Gearbox)
3 (a) is a left side view of the gear box 43, FIG. 3 (b) is a right side view thereof, and FIG. 3 (c) is cut along line AA in FIG. 3 (a). FIG. 3D is a cross-sectional view taken along the line BB in FIG. 3A.

  As described above, the gear box 43 is a gear-type transmission mechanism that transmits the pulley output rotation of the first belt-pulley transmission mechanism 42 to the reel rotation main shaft 44. The gear box 43 of this example is a gear box for switching between forward and reverse rotations, and the pulley output rotation can be transmitted to the reel rotation main shaft 44 by decelerating with a first reduction ratio while maintaining the same rotation direction. Transmission gear train 61, pulley output rotation, the second transmission gear train 62 that can be transmitted to the reel rotation main shaft 44 by rotating the rotation direction in the reverse direction and decelerating at a second reduction ratio, and pulley A switching mechanism 63 is provided that switches the output rotation transmission path to one of the first transmission gear train 61 and the second transmission gear train 62.

  Referring to FIG. 3 in detail, inside the case 64 of the gear box 43, there are an input side gear 65, a sliding transmission gear 66, a reverse rotation transmission gear 67, and an output side gear 68 which are gear box input shafts. Are supported so as to be rotatable around parallel axes.

  The input side gear 65 is a gear having a large tooth width, and a central shaft hole 65a is formed at the center thereof. One end of the central shaft hole 65a communicates coaxially with an input side shaft hole 64a formed in the right side plate portion of the case 64. The left shaft end of the output pulley shaft 52 is inserted into the central shaft hole 65 a via the input side shaft hole 64 a and is connected and fixed to the input side gear 65.

  The sliding transmission gear 66 is supported on the outer peripheral surface of a rotating cylinder 69 rotatably supported in the case 64 by spline coupling or the like so as to be integrally rotated and slidable in the axial direction. The sliding transmission gear 66 is integrally formed with a large-diameter gear 66 a that is always meshed with the input-side gear 65 and a small-diameter gear 66 b that is not meshed with the input-side gear 65. The slide type transmission gear 66 is engaged with the shift fork 70 as shown in FIG.

  When the shift fork 70 is fixed to the position indicated by the solid line in the drawing by the plunger 71 attached to the case 64, the sliding transmission gear 66 connected thereto is also held at the forward rotation slide position 66F indicated by the solid line. The shift fork 70 includes a knob 70a protruding from the left side surface of the case 64, and when the knob 70a is pulled out, the shift fork 70 is positioned at a position shifted to the left side by the plunger 71 and is connected to the slide type transmission. The gear 66 is positioned at a reverse rotation slide position 66R indicated by an imaginary line in FIGS.

The output side gear 68, which is a gear box output shaft, has a forward rotation small diameter gear 68b formed on the right side of the body on the outer peripheral surface of the rotating cylinder 68a, and a reverse rotation large diameter gear 68c formed integrally on the left side of the body. Both end portions of the rotating cylinder 68a are exposed on the left and right side surfaces of the case 64, and output side shaft holes 68d formed therein are opened to the left and right. The shaft end portion 44a on the left side of the reel rotating main shaft 44 is inserted into the output side shaft hole 68d from the right side of the machine body, and is connected and fixed to the output side gear 68 so as to rotate together with a key (not shown). . Further, as indicated by an imaginary line in FIG. 3C from the left side surface of the case, a fixing bolt 73 is attached to the reel rotating main shaft 44 through a bolt hole formed at the center thereof. Screwed to the shaft end.

  The forward rotation small diameter gear 68b of the output side gear 68 can mesh with the large diameter gear 66a of the slide type transmission gear 66 positioned at the forward rotation slide position 66F. Accordingly, when the slide type transmission gear 66 is positioned at the forward rotation slide position 66F, the rotation of the input side gear 65 that rotates integrally with the output side pulley shaft 52 is via the large-diameter gear 66a of one slide type transmission gear 66. Then, it is transmitted to the small-diameter gear 68b of the output side gear 68 and transmitted to the reel rotation main shaft 44 connected thereto.

  Therefore, the first transmission gear train 61 that transmits the pulley output rotation to the reel rotation main shaft 44 by reducing the pulley output rotation by the first reduction ratio while maintaining the same rotation direction by the gears 65, 66a, and 68b. Composed. By adjusting the number of teeth of each gear constituting the first transmission gear train 61, the transmission rotation can be decelerated at a desired reduction ratio. In this example, at the time of forward rotation, the reduction gear ratio of the gear train is set to the first reduction gear ratio so that the reel of each cutting unit can be rotated at high speed.

  Next, the reverse rotation transmission gear 67 disposed adjacent to both the sliding transmission gear 66 and the output side gear 68 includes a large-diameter gear 67a and a small-diameter gear 67b disposed adjacent to the right side in a coaxial state. ing. These large-diameter gear 67a and small-diameter gear 67b are spline-coupled to the outer peripheral surface of a rotating cylinder 67c, which is a common rotating shaft attached to the case 64 in a rotatable state, and these three members are integrated. Rotate. The large-diameter gear 67 a can mesh with the small-diameter gear 66 b of the sliding transmission gear 66 positioned at the reverse rotation slide position 66 R, and the small-diameter gear 67 b always meshes with the large-diameter gear 68 c of the output side gear 68.

  Therefore, when the slide type transmission gear 66 is positioned at the reverse rotation slide position 66R, the rotation of the input side gear 65 that rotates integrally with the output side pulley shaft 52 causes the small diameter gear 66b of the slide type transmission gear 66 and the reverse rotation transmission gear to rotate. The two rotation gears 67 are transmitted to the large-diameter gear 68c of the output side gear 68 in a state where the rotation direction is switched to the reverse rotation, and are transmitted to the reel rotation main shaft 44 connected thereto.

  Therefore, by these gears 65, 66 b, 67 a, 67 b, 68 c, the pulley output rotation is reversely rotated in the rotation direction, decelerated at the second reduction ratio, and transmitted to the reel rotation main shaft 44. A transmission gear train 62 is configured. Since the reverse rotation is performed in the polishing operation of the cutting unit, the reduction ratio of the gear train is set so that the reel of the cutting unit rotates at a low speed during the reverse rotation.

  Further, the sliding transmission gear 66 and the shift fork 70 constitute a switching mechanism 63 that switches the pulley output rotation transmission path to one of the first transmission gear train 61 and the second transmission gear train 62. The

(Gearbox mounting part)
Next, the gear box mounting portion on the side of the fuselage frame 5 to which the gear box 43 having the above configuration is mounted will be described. The gear box 43 of this example can move from the first position on the right side to the second position on the left side along the body width direction with respect to the gear box mounting portion provided on the body frame 5. The first position is a position where the gear box 43 can transmit the pulley output rotation to the reel rotation main shaft 44, and the second position is the gear box 43 where the first belt-pulley transmission mechanism 42 and the reel rotation. This is a position separated from the main spindle 44.

  Also, the second position is between the gear box 43 and the shaft end of the reel rotation main shaft 44, the left V belt 57L of the left front belt pulley type transmission mechanism 45L, and the first belt pulley type. This is a position where a gap is formed in which the two V belts 54 of the transmission mechanism 42 can be taken out. The rear belt / pulley transmission mechanism 46 has no obstacle such as the gear box 43, so the V belt 48 can be easily removed from the pulley attached to the reel rotation main shaft 44. When the V belt 48 of the rear belt / pulley transmission mechanism 46 is removed, the right V belt 57R of the right front belt / pulley transmission mechanism 45R can be easily removed.

  With reference to FIG. 2, FIG. 3, and FIG. 4, the gear box attachment part of the body frame 5 which attaches the gear box 43 is demonstrated. FIG. 4A is an explanatory view of the state in which the gear box 43 is attached to the first position in the gear box attachment portion 80 as viewed from the rear side of the body, and FIG. It is explanatory drawing at the time of seeing the state slid to the position of 2 from the body rear side. In FIG. 4B, a part of the airframe is omitted, and the positional relationship between the gear box 43 and the shaft end surfaces of the reel rotation main shaft 44 and the output-side pulley shaft 52 is shown.

  First, as shown in FIGS. 2 and 4, the gear box mounting portion 80 includes two columnar guide shafts 81 and 82 extending horizontally in the machine width direction parallel to the reel rotation main shaft 44. Both end portions of these guide shafts 81 and 82 are detachable with bolts or the like, and are mounted between brackets 83 and 84 that face each other at regular intervals in the body width direction provided on the body frame 5 side. Has been passed.

  On the other hand, as can be seen from FIGS. 2 and 3, the mounting bracket 85 projects vertically on the end face of the case 64 of the gear box 43 facing the rear of the machine body. Guide shaft holes 86 and 87 extending in the body width direction are formed at the top and bottom ends of the mounting bracket 85. Two guide shafts 81 and 82 which are parallel to each other extend through the guide shaft holes 86 and 87 so as to be slidable.

  In a state in which the gear box 43 is positioned at the first position 43A shown in FIGS. 2B and 4A, the output-side pulley shaft is inserted into the center shaft hole 65a and the output-side shaft hole 68d of the gear box 43, respectively. The shaft end portion on the left side of 52 and the shaft end portion 44a on the left side of the reel rotation main shaft 44 are inserted, and can be connected and fixed to the input side gear 65 and the output side gear 68, respectively. On the other hand, when a part such as a fixing bolt 73 for fixing the shaft end portion 44a of the reel rotating main shaft 44 is removed from the left side surface of the gear box 43 facing the outer side in the machine width direction, The box 43 can be slid along the two guide shafts 81 and 82 from the first position 43A to the outside (left side) in the body width direction.

  As shown in FIG. 4B, when the gear box 43 is slid to the second position 43B on the outer side in the body width direction, the output side pulley shaft is moved from the center shaft hole 65a and the output side shaft hole 68d of the gear box 43. 52 and the reel shaft main shaft 44 are pulled out. In this state, a gap 88 for removing the V-belt is formed between the shaft end surface 44 b of the reel rotation main shaft 44 and the right side surface of the gear box 43. Similarly, a gap 89 for removing the V-belt is also formed between the shaft end surface 52 a of the output pulley shaft 52 and the right side surface of the gear box 43. Using these gaps 88 and 89, the V belt 57L of the front belt / pulley transmission mechanism 45L and the two V belts 54 of the first belt / pulley transmission mechanism 42 can be removed. Further, after the gear box 43 is slid to the second position 43B, the gear box 43 can be removed from the body frame 5 by removing the two guide shafts 81 and 82 from the brackets 83 and 84 of the body frame 5. Is possible.

(Gearbox for switching forward speed)
In the above example, the gear box 43 for forward / reverse rotation switching is attached to the transmission path of the engine rotation output so that the cutting unit can be rotated in reverse during the polishing operation of the cutting unit.

  On the other hand, in the turf cutting operation, there is a case where it is desired to switch between a cutting operation with a wide cutting pitch and a cutting operation with a narrow cutting pitch by rotating the cutting unit at a higher speed as necessary. In order to cope with such a case, it is desirable that a gear box for switching the forward rotation speed can be attached to the gear box mounting portion 80 instead of the gear box 43 for switching the forward / reverse rotation.

  FIG. 5A is a left side view showing an example of the gear box for switching the positive rotation speed, and FIG. 5B is a cross-sectional view showing a portion cut along the line CC. The gear box 90 for switching the forward rotation speed includes a transmission gear train 91 that can reduce the pulley output rotation to the reel rotation main shaft 44 by decelerating the rotation of the pulley output at the first reduction ratio, and the pulley output. The transmission gear train 92 capable of decelerating the rotation at a third reduction ratio that can be reduced to be smaller than the first reduction ratio and transmitting the rotation to the reel rotation main shaft 44 with the same rotation direction, and the pulley output rotation And a switching mechanism 93 that switches the transmission path to one of the transmission gear trains 91 and 92.

  Referring to FIG. 5 in detail, an input side gear 95, a slide type transmission gear 96, and an output side gear 97 are rotatably arranged inside the case 94 of the gear box 90. The input side gear 95 has a small diameter gear 95a formed at the left end thereof, and a large diameter gear 95b formed at the right end thereof. The sliding transmission gear 96 can slide between a standard speed rotation position 96A indicated by a solid line in the drawing and a right-side high speed rotation position 96B indicated by an imaginary line. The slide of the sliding transmission gear 96 is mounted with a shift fork (not shown) having the same structure as the shift fork shown in FIG. doing. The output side gear 97 is a gear having a wide tooth width, and always meshes with the large-diameter gear 96a regardless of the sliding position of the sliding transmission gear 96.

  When the sliding transmission gear 96 is slid to the standard speed rotation position 96A, rotation is transmitted from the small diameter gear 95a of the input side gear 95 to the output side gear 97 via the large diameter gear 96a. The rotational speed is greatly reduced from the side of the small-diameter gear 95 a having a small number of teeth through the large-diameter gear 96 a having a large number of teeth, and transmitted to the output-side gear 97. Therefore, the reel rotation main shaft 44 (see FIG. 1) rotates at a low speed, so that the lawn mowing operation is performed while the mowing unit also rotates at the standard speed.

  On the other hand, when the sliding transmission gear 96 is slid to the high speed rotation position 96B, the engagement between the large diameter gear 96a and the input side small diameter gear 95a is released. Instead, the small diameter gear 96b and the input side large diameter are disengaged. The gear 95b is engaged. Therefore, the rotational speed is transmitted from the large-diameter gear 95b having a large number of teeth on the input side to the output-side gear 97 through the small-diameter gear 96b having a small number of teeth without being greatly decelerated. As a result, the lawn mowing operation is performed while rotating the mowing unit at a speed higher than the standard speed.

  Here, the gear box 90 having this configuration can be mounted on the gear box mounting portion 80 common to the gear box 43 of the above-described example. In other words, the input side shaft hole 101 and the output side shaft hole 102 are formed in the gear box 90 at the same interval as the gear box 43, and the output side pulley shaft 52 and the reel rotation main shaft 44 are respectively provided. The shaft end 44a can be inserted and connected and fixed.

  A mounting bracket 103 is formed in the case 94 of the gear box 90, and two guide shaft holes 104 and 105 are formed at the same interval as in the case of the gear box 43. Therefore, the gear box 90 can be attached to the gear box attachment portion 80 of the body frame 5 in the same manner as the gear box 43. Similarly, it can be slid and removed.

DESCRIPTION OF SYMBOLS 1 Lawn mower, 2 traveling body, 3L left cutting unit, 3R right cutting unit, 4 central cutting unit, 5 body frame, 6L driving wheel, 6R driving wheel, 7 steering wheel, 8 front cover, 9 engine, 10L, 10R fender , 11 Handle, 12 Accelerator lever, 13 Clutch lever, 13A Cutting position, 13B Engagement position, 14 Starter switch, 15 Choke knob, 16 Cutter lifting lever, 17 Seat, 18 Fuel tank, 19 Hydraulic oil tank, 20F Forward travel shift pedal , 20R reverse travel shift pedal, 21 front roller, 22 rear roller, 23 cutting blade, 24 reel shaft, 25 reel, 26 fixed blade, 27 bucket, 31L, 31R lift arm, 32L, 32R front arm, 33 front roller, 34 Rear roller, 35 cutting blade, 3 6 reel shaft, 37 reel, 38 fixed blade, 39 bucket, 41 engine output shaft, 42
First belt / pulley transmission mechanism, 43 gear box, 43A first position, 43B second position, 44 reel rotation main shaft, 44a shaft end, 44b shaft end face, 45L, 45R front belt / pulley transmission Mechanism, 46 Rear side belt / pulley type transmission mechanism, 47a, 47b Bearing, 51 Engine side pulley, 52 Output side pulley shaft, 52a Shaft end face, 53 Gear box side pulley, 54 V belt, 55L Left main shaft side pulley, 55R Right Main pulley, 56L Left reel shaft pulley, 56R Right reel shaft pulley, 57L Left V belt, 57R Right V belt, 58 Tension roller, 59 Link mechanism, 61 First transmission gear train, 62 Second transmission Gear train, 63 switching mechanism, 64 case, 64a input side shaft hole, 65 input side gear, 65a center shaft hole 66 sliding transmission gear, 66F forward rotation slide position, 66R reverse rotation slide position, 66a
Large-diameter gear, 66b Small-diameter gear, 67 Reverse rotation transmission gear, 67a Large-diameter gear, 67b Small-diameter gear, 67c Rotating cylinder, 68 Output side gear, 68a Rotating cylinder, 68b Forward rotation small-diameter, 68c Reverse rotation large-diameter Gear, 68d Output side shaft hole, 69 Rotating cylinder, 70 Shift fork, 70a Knob, 71 Plunger, 72 Lid, 73 Fixing bolt, 80
Gear box mounting portion, 81, 82 guide shaft, 83, 84 bracket, 85 mounting bracket, 86, 87 guide shaft hole, 88, 89 clearance, 90 gear box, 91 transmission gear train, 92 transmission gear train, 93 switching mechanism, 94 case, 95 input side gear, 95a small diameter gear, 95b large diameter gear, 96 sliding transmission gear, 96A standard speed rotational position, 96B high speed rotational position, 97 output side gear, 98 knob, 101 input side shaft Hole, 102 Output side shaft hole, 103 Mounting bracket, 104, 105 Guide shaft hole

Claims (6)

The rotation of the engine output shaft is transmitted to the reel rotation main shaft via the first belt / pulley transmission mechanism, and the rotation of the reel rotation main shaft is transmitted to the reel via the second belt / pulley transmission mechanism. A belt-driven reel-type lawn mower that transmits to the reel shaft of the type mowing unit,
A gear box for transmitting the pulley output rotation of the first belt-pulley transmission mechanism to the reel rotation spindle;
A first transmission gear train capable of decelerating the pulley output rotation with a first reduction ratio and transmitting it to the reel rotation main shaft while maintaining the same rotation direction;
A second transmission gear train capable of transmitting the pulley output rotation to the reel rotation main shaft by decelerating the rotation direction in the reverse direction and decelerating at a second reduction ratio;
A switching mechanism for switching the transmission path of the pulley output rotation to one of the first transmission gear train and the second transmission gear train;
Equipped with a,
The gear box is supported movably from a first position to a second position with respect to a gear box mounting portion provided on the lawn mower body frame,
The first position is a position where the gear box can transmit the pulley output rotation to the reel rotation main shaft,
In the second position, the gear box is separated from the first belt-pulley transmission mechanism and the reel rotation main shaft, and between the gear box and the shaft end of the reel rotation main shaft, A belt-driven reel-type lawn mower characterized in that a gap is formed in which a belt of the second belt-pulley type transmission mechanism can be taken out . Instead of the second transmission gear train, the gearbox decelerates the pulley output rotation at a third reduction ratio that can be reduced to be smaller than the first reduction ratio while maintaining the same rotation direction. And having a third transmission gear train that can be transmitted to the reel rotation main shaft,
2. The belt-driven reel lawn mower according to claim 1, wherein the switching mechanism switches a transmission path of the pulley output rotation to one of the first transmission gear train and the third transmission gear train. Machine. The rotation of the engine output shaft is transmitted to the reel rotation main shaft via the first belt / pulley transmission mechanism, and the rotation of the reel rotation main shaft is transmitted to the reel via the second belt / pulley transmission mechanism. A belt-driven reel-type lawn mower that transmits to the reel shaft of the type mowing unit,
A gear box for transmitting the pulley output rotation of the first belt-pulley transmission mechanism to the reel rotation spindle;
A gearbox mounting portion provided on the lawn mower body frame, to which the gearbox is detachably mounted;
Have
The gear box is supported movably from a first position to a second position with respect to a gear box mounting portion provided on the lawn mower body frame,
The first position is a position where the gear box can transmit the pulley output rotation to the reel rotation main shaft,
In the second position, the gear box is separated from the first belt-pulley transmission mechanism and the reel rotation main shaft, and between the gear box and the shaft end of the reel rotation main shaft, A position where a gap is formed in which the belt of the second belt-pulley transmission mechanism can be taken out;
The gear box is one of a forward / reverse rotation switching gear box and a forward rotation speed switching gear box,
The forward / reverse rotation switching gear box is:
A first transmission gear train capable of decelerating the pulley output rotation with a first reduction ratio and transmitting it to the reel rotation main shaft while maintaining the same rotation direction;
A second transmission gear train capable of transmitting the pulley output rotation to the reel rotation main shaft by decelerating the rotation direction in the reverse direction and decelerating at a second reduction ratio;
A first switching mechanism that switches the transmission path of the pulley output rotation to one of the first transmission gear train and the second transmission gear train;
With
The forward rotation speed switching gearbox is
A first transmission gear train capable of decelerating the pulley output rotation with a first reduction ratio and transmitting it to the reel rotation main shaft while maintaining the same rotation direction;
A third transmission gear capable of decelerating the pulley output rotation at a third reduction ratio that can be reduced to be smaller than the first reduction ratio and transmitting the pulley output rotation to the reel rotation spindle. Columns,
A second switching mechanism that switches the transmission path of the pulley output rotation to one of the first transmission gear train and the third transmission gear train;
A belt-driven reel lawn mower characterized by comprising: 4. The belt-driven reel-type lawn mower according to claim 1 , wherein the gear box is removable from the gear box mounting portion at the second position . 5. The gear box mounting portion has a guide shaft attached to the lawn mower body frame in a state extending in a sliding direction parallel to the reel rotation main shaft,
The gear box is slidable along the guide shaft between the first position and the second position;
The gear box is
A guide shaft hole extending through the slide direction in a state in which the guide shaft is slidable, and
An input side shaft hole into which an output side pulley shaft of the first belt-pulley transmission mechanism is inserted from the first position side along the sliding direction;
5. The belt-driven reel type according to claim 4 , wherein an axial end portion of the reel rotation main shaft includes an output side shaft hole inserted from the first position side along the sliding direction. Lawn mower. With front and rear wheels,
Left and right reel type mowing units located in front of the front wheels;
A central reel-type mowing unit located behind the front wheel;
A power transmission mechanism for transmitting rotation of the engine output shaft to the front wheels;
Reel mower belt driven according to it has claim 5 comprising a.

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