JP7523251B2 - Riding Groove Cutting Machine - Google Patents

Description

The present invention relates to a riding groove cutting machine.

Conventionally, riding furrow cutting machines that cut furrows in farm fields (paddy fields) to quickly drain the fields are known. In this riding furrow cutting machine, an operator sits astride a seat attached to the main frame, and while moving forward by rotating the wheels driven by the engine, cuts furrows in the field using a furrow cutting section at the rear of the main frame. The following Patent Document 1 describes a machine in which the operator operates a handle to steer the wheels and change the direction of travel.

Patent No. 4032109

However, with the riding furrow cutter described in Patent Document 1, depending on the field, the steering wheel may suddenly be taken away, making it difficult to drive stably.

The present invention was made to solve these problems, and aims to provide a riding trench cutting machine that can prevent the handle for steering the wheels from being suddenly taken off and allows for stable driving.

The riding groove cutting machine (100) according to the present invention is a riding groove cutting machine (100) in which an operator sits on a seat (12) provided on a main frame (9) and cuts a groove using a groove cutting section (7) while moving forward by rotating the wheels (6). The riding groove cutting machine (100) comprises a handle (1) for steering the wheels (6), a handle shaft (2) connected to a handle mounting section (41) of the handle (1), a connecting bracket (3) connected to the lower part of the handle shaft (2) and connected to the wheels (6), and a handle shaft (2) provided at the front of the main frame (9) for freely rotating. The handle shaft (2) has a rotation support pipe (10), and either a female screw portion (39) or a male screw portion (43) is provided on the upper part of the handle shaft (2). When the other screw portion (43) of the female screw portion (39) or the male screw portion (43) is screwed into one screw portion (39), the handle attachment portion (41) and the handle shaft rotation support pipe (10) are sandwiched between the other screw portion (43) and the connecting bracket (3), and the handle shaft (2) can be pulled up by tightening the other screw portion (43).

According to this riding groove cutting machine (100), the female screw portion (39) or the male screw portion (43) provided on the upper part of the handle shaft (2) is screwed with the other screw portion (43), so that the handle attachment portion (41) that connects the handle (1) to the handle shaft (2) and the handle shaft rotation support pipe (10) that is provided at the front of the main body frame (9) and connects the handle shaft (2) rotatably are sandwiched between the connecting bracket (3) that is connected to the lower part of the handle shaft (2) and to the wheel (6) and the other screw portion (43). Then, by pulling up the handle shaft (2) by tightening the other screw portion (43), the tightening force increases and the sliding resistance of the handle shaft (2) increases, making it possible to suppress the handle (1) from being suddenly taken off. As a result, stable driving can be performed. In addition, the degree to which the sliding resistance of the handle shaft (2) is increased can be changed according to the operator's preference by adjusting the degree to which the other screw portion (43) is tightened, allowing the operation of the handle (1) to be adjusted to suit the field.

Here, if the vehicle is provided with elastic bodies (25a, 25b) that pull the handle shaft (2) toward the neutral position around the rotation axis of the handle shaft (2), when the handle shaft (2) rotates from the neutral position around the rotation axis, the elastic bodies (25a, 25b) repel the handle shaft (2) back to the neutral position, making it easier to return the handle (1) to the neutral position and maintaining stable straightness. On the other hand, if the handle shaft (2) is returned to the neutral position too quickly by the elastic bodies (25a, 25b), the sliding resistance of the handle shaft (2) is increased by tightening the other screw portion (43), so that the sudden rotation of the handle (1) is suppressed and the direction of travel changes slowly. As a result, stable driving can be achieved.

In this way, the present invention can prevent the steering wheel from being suddenly yanked, allowing for stable driving.

FIG. 1 is a side view showing a riding groove cutting machine according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view of the riding groove cutting machine shown in FIG. 1 as seen from above and behind. FIG. 3 is a longitudinal cross-sectional view showing the handle, handle shaft, handle mounting portion, tightening adjustment portion, handle shaft rotation support pipe, connecting bracket, and handle shaft rotation range regulating means in FIGS. 1 and 2, and shows the case where the handle is fixed. FIG. 3 is a partially exploded front view in cross section showing the handle, the handle shaft, the handle mounting portion, the tightening adjustment portion, the handle shaft rotation support pipe, the connecting bracket, etc. in FIGS. 1 and 2 . 4 is a plan view showing an upper plate and a knob bolt constituting the handle shaft rotation range restricting means in FIG. 3 . 4 is a plan view showing a middle plate constituting the handle shaft rotation range restricting means in FIG. 3 . FIG. 4 is a plan view showing a lower plate constituting the handle shaft rotation range restricting means in FIG. 3 . FIG. 2 is a partially sectional side view showing a groove cutting portion, a groove cutting portion rotation range regulating means, and a neutral return mechanism in FIG. 1 . FIG. 9 is a plan view showing the neutral return mechanism in FIG. 8 . FIG. 9 is a view taken along the line X-X in FIG. 8 . FIG. 9 is a rear view showing the groove rotation range regulating means in FIG. 8 . FIG. 2 is a plan view showing the phase relationship between the wheel and the groove cutting portion, showing a state in which the wheel and the groove cutting portion are located in a neutral position. FIG. 11 is a plan view showing the phase relationship between the wheel and the groove cutting portion, illustrating the state in which the wheel has been turned clockwise from the neutral position. FIG. 11 is a plan view showing the phase relationship between the wheel and the groove cutting portion, illustrating the state in which the wheel has been turned counterclockwise from the neutral position. This is a partially cross-sectional exploded front view showing the handle, handle shaft, handle mounting portion, tightening adjustment portion, handle shaft rotation support pipe, connecting bracket, etc. of a riding groove cutting machine according to a second embodiment of the present invention. This is a partially cross-sectional exploded front view showing the handle, handle shaft, handle mounting portion, tightening adjustment portion, handle shaft rotation support pipe, connecting bracket, etc. of a riding groove cutting machine according to a third embodiment of the present invention.

Below, a preferred embodiment of the riding groove cutting machine according to the present invention will be described with reference to the attached drawings. Figures 1 to 14 show a first embodiment of the present invention, Figure 15 shows a second embodiment of the present invention, and Figure 16 shows a third embodiment of the present invention. In each figure, the same elements are given the same reference numerals, and duplicated explanations will be omitted.

First, the first embodiment shown in Figures 1 to 14 will be described. Figures 1 and 2 are views showing a riding groove cutting machine according to the first embodiment of the present invention, Figure 3 is a vertical cross-sectional view showing the handle, handle shaft, handle attachment, tightening adjustment, handle shaft rotation support pipe, connecting bracket, and handle shaft rotation range regulating means, etc., and is a view showing the case where the handle is fixed, Figure 4 is a partially cross-sectional exploded front view showing the handle, handle shaft, handle attachment, tightening adjustment, handle shaft rotation support pipe, and connecting bracket, etc., Figures 5 to 7 are views showing the handle shaft rotation range regulating means, Figure 8 is a partially cross-sectional side view showing the groove cutting portion, the groove cutting portion rotation range regulating means, and the neutral return mechanism, Figure 9 is a plan view showing the neutral return mechanism, Figure 10 is a view seen from the X-X arrow in Figure 8, Figure 11 is a rear view showing the groove cutting portion rotation range regulating means, and Figures 12 to 14 are plan views showing the phase relationship between the wheel and the groove cutting portion. In the following description, terms indicating directions such as "front," "rear," "up," "down," "left," and "right" are based on the forward direction being defined as the direction of movement when the riding trencher is placed on a horizontal surface.

As shown in Figures 1 and 2, the riding furrow cutter 100 is equipped at its front with a handle 1 that is held by the operator, a handle shaft 2 (see Figure 3) that extends diagonally downward and forward from the bottom of the handle 1, a connecting bracket 3 that is connected to the lower end of the handle shaft 2 and is offset toward the front of the page and extends downward at the same angle as the handle shaft 2, a gear case 4 that is connected to the connecting bracket 3, and wheels 6 that are connected to the inner hub of the gear case 4 and have flat anti-slip pads 5 evenly spaced around the outer periphery. At the rear of the machine, it is equipped with a furrow cutter 7 for cutting furrows in the field, and a furrow cutter shaft 8 that is connected to the furrow cutter 7 and extends diagonally upward and backward.

The riding trencher 100 also has a main frame 9 that extends downward in the front-rear direction. A handle shaft rotation support pipe 10 is provided at the front of the main frame 9 for inserting the handle shaft 2 and connecting it so that it can rotate freely.

The main frame 9 is provided with a seat 12 at the top, approximately at the center in the axial direction, for the operator to sit astride. The seat 12 can be adjusted in the vertical direction. The rear side of the axial center of the main frame 9 is provided with a curved section 14 that curves in an approximately U-shape, bulging out to the side (toward the back of the page), so that the transmission shaft housing pipe 13 described below can enter and swing left and right (perpendicular to the page) around the handle shaft 2 as the rotation axis. A groove cutting section shaft rotation support pipe 11 is provided at the rear end of the main frame 9 extending rearward from the curved section 14, and the groove cutting section shaft 8 is inserted into the groove cutting section shaft rotation support pipe 11 and connected to it so as to be freely rotatable.

The furrow cutting section 7 is tapered in a V-shape when viewed from above, and is made up of a series of flat plates that form a V-shaped furrow when viewed from the front to back. A flat plate that extends horizontally outward along the V-shape is connected to the upper end of the flat plate that forms the V-shaped furrow. When the furrow cutting section 7 cuts the furrow, the tip of the V-shaped furrow is pushed into the field, and the soil pushed up and out of the V-shaped furrow is spread to the left and right.

The gear case 4 houses a spiral bevel gear and the like, and a transmission shaft housing pipe 13, which houses a transmission shaft inside and extends in the front-rear direction with the rear raised, is connected to the gear case 4, and the rear end of the transmission shaft housing pipe 13 is connected to the prime mover 15. The transmission shaft housing pipe 13 extends rearward while being slightly inclined to the right (the back of the page) by the spiral bevel gear of the gear case 4. The prime mover 15 is disposed behind the seat 12, and the transmission shaft housing pipe 13 is disposed so that it passes under the seat 12, passes inside the curved portion 14 of the main frame 9, and reaches the prime mover 15. The driving force of the prime mover 15 is transmitted to the hub of the gear case 4 via the transmission shaft, and the wheels 6 rotate. The connecting bracket 3 and the transmission shaft housing pipe 13 are connected by a reinforcing frame 29.

As shown in Figures 3 and 4, the connecting bracket 3 has a bracket portion 37 at its upper portion that extends in the left-right direction, and the handle shaft 2 is erected on the bracket portion 37. A female screw portion 39 is recessed into the upper end surface of the upper portion of the handle shaft 2.

The handle shaft rotation support pipe 10 is placed on the bracket part 37 and is fitted onto the handle shaft 2, and is rotatably connected to the handle shaft 2 via two flange-type bearings (unlubricated bearings) 16, 16 housed inside it facing each other vertically.

Two spacers 40, 40 are arranged on the handle shaft rotation support pipe 10, fitted onto the handle shaft 2. On the upper spacer 40, a handle mounting bracket 41, which serves as a handle mounting part that sandwiches the lower central part of the handle 1 from the front and rear, is connected to the handle shaft 2 so as to sandwich the handle shaft 2 from the front and rear. In other words, the handle mounting bracket 41 is fitted onto and fixed to the handle shaft 2.

A top cap 42 is placed on the handle mounting bracket 41. The top cap 42 has a recess in the center of the top to accommodate the head of the bolt 43 as a male screw, and a through hole through which the shaft of the bolt 43 passes.

Then, by screwing the bolt 43 into the female threaded portion 39 of the handle shaft 2, the handle shaft rotation support pipe 10, spacers 40, 40, handle mounting bracket 41, and top cap 42 are sandwiched between the bolt 43 and the bracket portion 37 of the connecting bracket 3. Here, the bolt 43 and the female threaded portion 39 form a tightening adjustment portion for increasing the tightening force by clamping and increasing the sliding resistance (rotational resistance) of the handle shaft 2.

In addition, as shown in Figures 1 to 3, a handle shaft rotation range restriction means 17 that restricts the rotation range of the handle shaft 2 is provided on the front surface of the bracket portion 37 of the connecting bracket 3.

As shown in FIG. 3, the handle shaft rotation range restriction means 17 includes an upper plate 18 fixed to the front surface of the handle shaft rotation support pipe 10, and a middle plate 19 and a lower plate 20 fixed to the front surface of the bracket portion 37 and arranged below the upper plate 18 in a stacked manner with a space therebetween.

3 and 5, the knob bolt 21 is screwed into the upper plate 18. As shown in FIG. 6, the middle plate 19 is formed with a long hole 22 extending in an arc shape in a plan view with the handle shaft 2 as the rotation axis, and the tip of the knob bolt 21 can be inserted into the long hole 22 for loose fitting. As shown in FIG. 7, the lower plate 20 is formed with a through hole 23 below the knob bolt 21 into which the tip of the knob bolt 21 can be inserted. Then, as shown in FIG. 3, the knob bolt 21 is screwed into the upper plate 18, and the tip of the knob bolt 21 is inserted into the long hole 22 of the middle plate 19 (see FIG. 6), so that the handle shaft 2 and the handle 1 can be rotated. The rotation range of the handle shaft 2 and the handle 1 is the range in which the left and right ends of the long hole 22 of the middle plate 19 move and hit the tip of the knob bolt 21.

The knob bolt 21 can be further screwed into the upper plate 18 and the tip of the knob bolt 21 can be inserted into the through hole 23 (see FIG. 7) of the lower plate 20 to fix the handle shaft 2 and the handle 1 in an unrotatable state. Note that FIG. 3 shows the case where the handle shaft 2 and the handle 1 are fixed.

In this embodiment, the tip of the knob bolt 21 does not enter the through hole 23 of the lower plate 20, but is loosely fitted into the long hole 22 of the middle plate 19. Referring to FIG. 2, when the handle 1 is rotated (steered), the wheels 6 turn left and right (counterclockwise, clockwise) around the handle shaft 2 as the axis of rotation, and the transmission shaft housing pipe 13 and the prime mover 15 turn left and right (counterclockwise, clockwise). Note that a lever bolt or index plunger may be used instead of the knob bolt 21.

As shown in Figs. 1 and 2, a neutral return mechanism 24 is interposed between the transmission shaft housing pipe 13 and the grooved portion shaft 8. As shown in Figs. 1, 8 and 9, the neutral return mechanism 24 connects the transmission shaft housing pipe 13 and the grooved portion shaft 8 via coil springs 25a and 25b as elastic bodies that pull them toward a neutral position around the rotation axis. A front adjustment plate 26 extending in the left-right direction is connected to the transmission shaft housing pipe 13, and a rear adjustment plate 27 extending in the left-right direction is fixed to the grooved portion shaft 8 via a rotating bracket 31. The front adjustment plate 26 and the rear adjustment plate 27 are provided with a plurality of locking portions (locking holes) 28 for locking the ends of the coil springs 25a and 25b at intervals along the left-right direction (see Fig. 9).

As shown in Figures 1 and 2, the rotating bracket 31 is configured in an L-shape using a flat plate. The front end of the bottom plate 31a of the rotating bracket 31 that forms the L-shape is fixed to the rear end of the rear adjustment plate 27, and the groove cutting shaft 8 penetrates and is fixed to the bottom plate 31a.

As shown in Figures 2 and 9, the coil springs 25a, 25b are provided on both the left and right sides of a straight line connecting the rotational axes of the handle shaft 2 and the grooved portion shaft 8 in a plan view. Here, the right coil spring 25a is located below the front and rear adjustment plates 26, 27, and the left coil spring 25b is located above the front and rear adjustment plates 26, 27.

In addition, the engagement position of the left coil spring 25b with respect to the front adjustment plate 26 is offset to the left so that the groove cutting section 7, which is connected to the transmission shaft housing pipe 13, which is oblique in plan view, via the neutral return mechanism 24, is positioned in a neutral position facing forward in the traveling direction of the riding groove cutting machine 100 (to be aligned with the neutral position of the wheels 6), and exerts a stronger pulling force than the right coil spring 25a.

As shown in FIG. 8, the groove cutting shaft 8 is rotatably supported via a flange-type bearing (oil-free bearing) 36 housed in the groove cutting shaft rotation support pipe 11, and as shown in FIGS. 1, 2 and 8, a rotation bracket 31 fixed to the groove cutting shaft 8 and the groove cutting shaft rotation support pipe 11 are provided with a groove cutting rotation range restriction means 30 that restricts the rotation range of the groove cutting section 7.

The groove cutting section rotation range regulating means 30 includes a bolt 32 as a protruding member that protrudes rearward from the groove cutting section shaft rotation support pipe 11, and a regulating bracket 31b that forms an L-shape of the rotation bracket 31 and protrudes upward.

As shown in Figures 2, 8, 10 and 11, the restricting bracket 31b has a recess 33 at its top that is open upward and extends in the left-right direction, and the bolt 32 enters the recess 33. Therefore, when the groove cutting portion 7 and the groove cutting portion shaft 8 rotate, the restricting bracket 31b rotates around the groove cutting portion shaft rotation support pipe 11. The rotation range of the groove cutting portion 7 and the groove cutting portion shaft 8 is the range in which the restricting bracket 31b rotates and the bolt 32 hits the left and right ends that form the recess 33 of the restricting bracket 31b.

When using a riding groove cutting machine 100 having such a configuration, the operator sits astride the seat 12 and drives the prime mover 15. The driving force of the prime mover 15 is transmitted to the gears in the gear case 4 and the inner hub via the transmission shaft housed in the transmission shaft housing pipe 13, and the wheels 6 rotate as driving wheels.

At this time, the handle shaft 2 and the furrow cutting part shaft 8 are located in neutral positions around the rotation axis, and as shown in FIG. 12, the direction of the wheels 6 and the direction of the furrow cutting part 7 are aligned, so the riding furrow cutting machine 100 moves forward. At this time, the weight of the riding furrow cutting machine 100 and the operator is applied to the wheels 6 and the furrow cutting part 7, so that the furrow cutting part 7 following the wheels 6 forms a furrow in the field.

When the handlebar 1 is rotated while the riding groove cutting machine 100 is moving forward, the handlebar shaft 2, connecting bracket 3, wheels 6, gear case 4, transmission shaft housing pipe 13, and prime mover 15 rotate around the rotation axis of the handlebar shaft 2. For example, when the handlebar 1 is turned to the right, the wheels 6 turn to the right as shown in FIG. 13, and the direction of travel of the riding groove cutting machine 100 changes to the right. Also, when the handlebar 1 is turned to the left, the wheels 6 turn to the left as shown in FIG. 14, and the direction of travel of the riding groove cutting machine 100 changes to the left.

At this time, the groove cutting shaft 8 is connected to the transmission shaft housing pipe 13 via a neutral return mechanism 24 having coil springs 25a, 25b, so that the groove cutting part 7 rotates counterclockwise around the rotation axis of the groove cutting part shaft 8 as shown in FIG. 13 when the handlebars 1 are turned to the right, and rotates clockwise as shown in FIG. 14 when the handlebars 1 are turned to the left. In other words, the phase in which the handlebar shaft 2 rotates and the phase in which the groove cutting part 7 rotates are opposite phases, and the riding groove cutting machine 100 moves forward with the wheels 6 and the groove cutting part 7 facing in opposite directions.

In this state, the neutral return mechanism 24 operates to prevent the operating direction of the handle 1 from remaining the same, and the coil springs 25a and 25b rotate the handle 1 and the groove cutting portion 7 in the opposite direction to the above, returning them to the neutral position.

Depending on the field, the handle 1 may suddenly be taken off. In this embodiment, this is solved by tightening and adjusting the bolt 43 and the female screw portion 39. Specifically, the bolt 43, which holds the handle shaft rotation support pipe 10, spacers 40, 40, handle mounting bracket 41, and top cap 42 between the bolt 43 and the bracket portion 37 of the connecting bracket 3, is tightened.

Then, the handle shaft 2 is pulled up, and the tightening force increases, which increases the sliding resistance of the handle shaft 2 and prevents the handle 1 from being suddenly pulled out. As a result, stable driving is possible. In addition, the degree of increase in the sliding resistance of the handle shaft 2 can be changed according to the operator's preference by adjusting the degree of tightening of the bolt 43, and the operation of the handle 1 can be adjusted to suit the field.

In addition, since the handle shaft 2 is equipped with coil springs 25a, 25b that pull the handle shaft 2 toward the neutral position around the rotation axis of the handle shaft 2, when the handle shaft 2 rotates from the neutral position around the rotation axis, the coil springs 25a, 25b spring the handle shaft 2 back to the neutral position, making it easy to return the handle 1 to the neutral position and maintaining stable straightness. On the other hand, if the coil springs 25a, 25b return the handle shaft 2 to the neutral position too suddenly, the tightening of the aforementioned bolt 43 increases the sliding resistance of the handle shaft 2, suppressing sudden rotation of the handle 1 and slowly changing the direction of travel. As a result, stable driving can be achieved.

In addition, by releasing the screw engagement of the bolt 43 with the female threaded portion 39, the handle shaft rotation support pipe 10 and other parts can be removed, making it easy to replace or maintain sliding parts such as the flange-type bearing 16.

In addition, by placing one of the spacers 40, 40 between the bracket portion 37 of the connecting bracket 3 and the handle shaft rotation support pipe 10, the relative height of the main frame 9 of the handle 1 with respect to the seat 12 is lowered, and as a result, the height of the handle 1 can be adjusted.

In addition, this embodiment also provides the following actions and effects. That is, because the coil springs 25a, 25b are provided on both the left and right sides of the straight line connecting the rotation axes of the handle shaft 2 and the rotating bracket 31 (groove cut portion 7) in a plan view, the handle 1 is easily returned to the neutral position regardless of whether the handle 1 is turned to the left or right.

In addition, the handle shaft 2 and the rotating bracket 31 (groove cut portion 7) are pulled toward a neutral position around the rotation axis by the coil springs 25a and 25b, so the phase in which the handle shaft 2 rotates and the phase in which the groove cut portion 7 rotates can be made to be opposite phases, and the wheels 6 and the groove cut portion 7 face in opposite directions, reducing the turning radius and inner wheel difference, and allowing for tighter maneuverability.

In addition, the handle shaft rotation range restriction means 17 restricts the rotation range of the handle shaft 2, so the rotation range of the handle 1 is restricted, preventing interference with parts and excessive load caused by turning the handle 1 too far.

In addition, the groove cutting portion rotation range restriction means 30 is provided to restrict the rotation range of the groove cutting portion 7, so that the rotation range of the groove cutting portion 7 is restricted, preventing damage to parts and excessive load due to excessive rotation of the groove cutting portion 7.

In addition, by screwing in the knob bolt 21 and inserting the tip into the through hole 23 of the lower plate 20 to fix and lock the handle shaft 2, the furrow cutting section 7 can be lifted and the wheels 6 can be rolled while the handle 1 is not turned, making it easy to transport and move the riding furrow cutting machine 100 in the field, and it is safe because the handle 1, wheels 6, transmission shaft housing pipe 13, and prime mover 15 do not move.

In addition, by changing the mounting positions of the coil springs 25a, 25b relative to the locking portions 28 of the front adjustment plate 26 and rear adjustment plate 27 of the neutral return mechanism 24, the angle of the coil springs 25a, 25b can be adjusted to change the load, so that the difference in operating performance can be reduced even in fields where the handle 1 is easily snatched.

Figure 15 is a partially cutaway exploded front view showing the handle, handle shaft, handle attachment, tightening adjustment, handle shaft rotation support pipe, and connecting bracket of a riding groove cutting machine according to a second embodiment of the present invention.

The second embodiment differs from the first embodiment in that the flange-type bearing 16 of the handle shaft rotation support pipe 10 is eliminated, and thrust bearings 44, 44 are provided between the bracket portion 37 of the connecting bracket 3 and the handle shaft rotation support pipe 10, and between the handle shaft rotation support pipe 10 and the spacer 40.

It goes without saying that the second embodiment configured in this way provides the same effects and advantages as the first embodiment.

Figure 16 is a partially cutaway exploded front view showing the handle, handle shaft, handle attachment, tightening adjustment, handle shaft rotation support pipe, and connecting bracket of a riding groove cutting machine according to a third embodiment of the present invention.

The third embodiment differs from the first embodiment in that the upper part of the handle shaft 2 is replaced with a male threaded part 45 instead of the female threaded part 39, and a nut 46 is used as the female threaded part that screws into the male threaded part 45 instead of the bolt 43. In addition, a top cap 47 with a through hole in the center through which the male threaded part 45 of the handle shaft 2 passes is used instead of the top cap 42.

It goes without saying that the tightening adjustment part consisting of the male screw part 45 and the nut 46 will provide the same effects and advantages as the first embodiment.

The present invention has been specifically described above based on the embodiments, but the present invention is not limited to the above embodiments. For example, the flange-type bearings 16, 16 of the third embodiment may be eliminated, and thrust bearings 44, 44 may be used as in the second embodiment.

In the above embodiment, the groove cutting portion 7 is configured by connecting flat plates to form a V-shaped groove when viewed from above and a V-shaped groove when viewed from the front and rear, but it may also be shaped like an abacus bead.

In addition, in the above embodiment, a neutral return mechanism 24 is provided to return the handle and the groove cutting portion to a neutral position, but the present invention can also be applied to a riding groove cutting machine equipped with a neutral return mechanism that returns only the handle to the neutral position, such as the riding groove cutting machine described in JP 2018-27035 A. It can also be applied to a riding groove cutting machine that does not have a neutral return mechanism, and the groove cutting portion may be fixed, so in short, it can be applied to a riding groove cutting machine in which the handle is rotated.

1...Handle, 2...Handle shaft, 3...Connecting bracket, 6...Wheel, 7...Groove cutting section, 9...Main frame, 10...Handle shaft rotation support pipe, 12...Seat, 25a, 25b...Coil spring (elastic body), 39, 46...Female screw section, 41...Handle mounting bracket (handle mounting section), 43, 45...Male screw section, 100...Riding groove cutting machine.

Claims (3)

In a riding groove cutting machine (100), an operator sits on a seat (12) provided on a main frame (9) and cuts a groove using a groove cutting section (7) while moving forward by rotating wheels (6),
A handle (1) for steering the wheels (6);
A handle shaft (2) connected to a handle attachment portion (41) of the handle (1);
A connecting bracket (3) connected to a lower portion of the handle shaft (2) and connected to the wheel (6);
First and second spacers (40) fitted onto the handle shaft (2);
a handle shaft rotation support pipe (10) provided at the front of the main body frame (9) and rotatably connecting the handle shaft (2),
The handle shaft (2) is provided at its upper portion with either a female screw portion (39) or a male screw portion (43),
The other screw portion (43) of the female screw portion (39) or the male screw portion (43) is screwed into the one screw portion (39), so that the handle attachment portion (41) , the first and second spacers (40), and the handle shaft rotation support pipe (10) are sandwiched between the other screw portion (43) and the connecting bracket (3),
This riding groove cutting machine (100) is characterized in that by tightening the other screw portion (43), the handle shaft (2) is pulled up, thereby increasing the sliding resistance of the handle shaft (2). The riding groove cutting machine (100) according to claim 1, characterized in that it is provided with elastic bodies (25a, 25b) that pull the handle shaft (2) toward a neutral position around the rotation axis of the handle shaft (2). A top cap (42) having a through hole through which the shaft portion of the male screw portion (43) is inserted is disposed on the handle attachment portion (41),
The riding groove cutting machine (100) of claim 1 or 2, characterized in that the top cap, the handle mounting portion (41) and the handle shaft rotation support pipe (10) are sandwiched between the other screw portion (43) and the connecting bracket (3) by screwing the other screw portion (43) of the female screw portion (39) or the male screw portion (43) into the one screw portion (39).

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