JP7549810B2 - Rice transplanter - Google Patents

Description

The present invention relates to a rice transplanter that can be operated forward from the front of the machine body.

Conventionally, rice transplanters are known that have a handle part at the front end of the machine body that is roughly inverted U-shaped when viewed from the front, allowing forward operation from the front side of the machine body.

In this conventional rice transplanter, the seedling planting section located at the rear of the machine is very heavy, so when the machine is moved in and out of the field by climbing over the field ridges, the operator, after getting out of the machine, reaches out to the main shift lever from the front of the machine to move the machine forward while pushing down on the handle section. This makes it possible to climb over the field ridges while preventing the front of the machine from lifting up.

However, if the main shift lever is operated incorrectly, the machine may suddenly accelerate and come into contact with the operator.

In light of this situation, Patent Document 1 discloses a rice transplanter in which an operator can push down on the handle and rotate it downward, causing the hydrostatic continuously variable transmission to output power for traveling and moving the machine forward at a slow speed.

The handle of the rice transplanter described in Patent Document 1 is biased upward by a spring, and when the operator releases it, the handle rotates upward and the machine stops.

JP 2012-068978 A

However, if the operator trips and falls forward while pushing the handle down and slowly moving the machine forward, the handle will remain pressed down by the operator's weight.

In addition, the rice transplanter described in Patent Document 1 is configured so that the braking of the running wheels by the brake device is released while the handle is being pressed down, so the brake device will not be activated even if the operator reaches out and presses down the machine stop pedal.

As a result, there was a risk that the machine would continue to move forward with the operator clinging to the handle until the operator regained their balance and moved away from the handle, leaving room for improvement in order to improve operator safety.

Therefore, the present invention aims to provide a rice transplanter that can improve the safety of the operator while moving the machine forward at a slow speed.

The object of the present invention is to
A traveling vehicle body that travels in a field;
A rice transplanter equipped with a seedling planting unit attached to the rear of the traveling body,
The traveling vehicle body includes a handle portion disposed at a front end portion of the vehicle body, a hydrostatic continuously variable transmission that changes the speed of rotational power supplied from a power source of the vehicle body to output rotational power for traveling, a speed change rod that adjusts the output of the hydrostatic continuously variable transmission, a slow speed forward lever that moves the traveling vehicle body forward at a slow speed, and an operation transmission portion that transmits the operation of the slow speed forward lever to the speed change rod,
When the slow forward lever is operated while the traveling vehicle body is stopped, the operation transmission unit moves the speed change rod to change the inclination angle of a swash plate that changes the amount of oil discharged from the hydraulic pump of the hydrostatic continuously variable transmission, and a rotational power of a rotational speed at which the traveling vehicle body travels at a slow speed is output from the hydrostatic continuously variable transmission.
This is achieved by a rice transplanter characterized in that the slow forward lever is positioned near the handle portion, which is roughly inverted U-shaped when viewed from the front, at a position below the upper end of the handle portion, and at a position rearward of the front end of the handle portion.

In the present invention, the slow-speed forward lever located near the handle is operated to move the speed-change rod, changing the inclination angle of the swash plate of the hydrostatic pump of the hydrostatic continuously variable transmission, and power for traveling at a slow speed is output from the hydrostatic continuously variable transmission. Therefore, when moving the machine in and out of a field, the operator can operate the slow-speed forward lever to move the machine forward at a slow speed.

Furthermore, according to the present invention, since the slow-speed forward movement lever is located below the upper end of the handle, even if an operator stands in front of the machine and trips and falls forward while operating the slow-speed forward movement lever located near the handle, the operator is unlikely to come into contact with the slow-speed forward movement lever. This prevents the operator from tripping and falling over the handle, which would otherwise cause the machine to continue moving forward, improving safety.

In addition, according to the present invention, the slow-speed forward movement lever is located rearward of the front end of the handle, so that even if the operator is caught between the front end of the machine body and an obstacle located in front of the machine body, the operator is unlikely to come into contact with the slow-speed forward movement lever. This prevents the slow-speed forward movement lever from coming into contact with the operator and being held in an operated state, improving safety.

In addition, according to the present invention, the slow-speed forward lever does not protrude forward from the handle portion, so even if the rice transplanter is equipped with a slow-speed forward lever, the overall length of the machine can be reduced, and therefore the rice transplanter does not become bulky when loaded onto a truck, etc.

In a preferred embodiment of the present invention,
The operation transmission unit is equipped with a transmission prevention means that prevents the operation of the slow forward movement lever from being transmitted to the speed change rod when the slow forward movement lever is operated at a predetermined operating speed or faster.

According to this preferred embodiment of the present invention, the operation transmission unit that transmits the operation of the slow-speed forward lever to the speed-change rod is equipped with a transmission prevention means that prevents the operation of the slow-speed forward lever from being transmitted to the speed-change rod when the slow-speed forward lever is operated at a predetermined operating speed or faster. This makes it possible to prevent the traveling vehicle body 2 from unintentionally suddenly starting off if, for example, an operator accidentally touches the slow-speed forward lever 36, thereby further improving safety.

In a further preferred embodiment of the present invention,
The traveling vehicle body includes a brake device for braking the traveling wheels;
A brake pedal for actuating the brake device;
a travel stop lever connected to the brake pedal,
The travel stop lever is disposed at the front of the travel vehicle body,
When the travel stop lever is operated while the slow-speed forward lever is operated, the traveling wheels are braked by the brake device, and the speed change rod is moved in priority to the slow-speed forward operation by the slow-speed forward lever, so that the output of rotational power from the hydrostatic continuously variable transmission is stopped.

In this preferred embodiment of the present invention, when the slow forward movement lever is operated and the travel stop lever is operated, the brake device is activated and the output of rotational power by the hydrostatic continuously variable transmission is stopped, prioritizing the slow forward movement operation by the slow forward movement lever.

With this configuration, when the operator moves the machine over the edge of the field and moves it in and out of the field, he or she can operate the slow forward lever to move the machine forward at a slow speed while pressing down the handle, and when he or she wants to stop the machine, he or she can stop the machine by operating the travel stop lever while still operating the slow forward lever. This makes it safe and easy to move the machine in and out of the field.

In a further preferred embodiment of the present invention,
A spare seedling frame on which seedlings to be replenished to the seedling planting section are placed;
An empty box rack is provided above the spare seedling frame and capable of storing empty seedling boxes in a substantially upright position;
The empty box rack has a frame body that surrounds the front, back, left and right sides of the seedling boxes stored therein,
The frame body includes a pair of front and rear left and right extending portions extending in the left and right direction, and a pair of left and right front and rear extending portions extending in the front and rear direction so as to connect the pair of front and rear left and right extending portions,
The left and right extending portion is configured to be located at a lower position than the front and rear extending portion.

According to this preferred embodiment of the present invention, in the frame body surrounding the front, back, left and right of an empty seedling box, the pair of front and back left and right extension parts extending in the left and right direction are configured to be at a lower position than the pair of front and back left and right extension parts extending in the front and back direction, so that when an operator takes an empty seedling box in or out from the front or back of the frame body, the seedling box is unlikely to come into contact with the pair of front and back left and right extension parts surrounding the front and back of the seedling box. Therefore, seedling boxes can be easily taken in and out of the frame body of the empty box rack.

The present invention makes it possible to provide a rice transplanter that can improve operator safety while moving the machine forward at a slow speed.

FIG. 1 is a schematic left side view of a rice transplanter according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view of the rice transplanter shown in FIG. FIG. 3 is a control block diagram of the rice transplanter shown in FIG. FIG. 4 is a schematic plan view showing the operating range of the main shift lever shown in FIG. 5 is a schematic left side view showing the vicinity of the base end portion of the main shift lever located inside the front cover shown in FIG. 1. FIG. FIG. 6 is a schematic left side view showing the vicinity of the operation transmission unit located inside the front cover when the vehicle is stopped. FIG. 7 is a diagram showing the vicinity of HST. 8(a) is an exploded perspective view of the positioning mechanism shown in FIG. 6, FIG. 8(b) is an enlarged side view of a cutout window of the positioning mechanism, and FIG. 8(c) is an enlarged side view of a long hole of the positioning mechanism. FIG. 9 is a schematic left side view showing the state in the vicinity of the operation transmission unit when the main shift lever is operated to the forward region. FIG. 10 is a schematic left side view showing the state in the vicinity of the operation transmission unit when the main shift lever is operated to the reverse range. FIG. 11 is a schematic perspective view of the vicinity of the traveling vehicle body shown in FIG. FIG. 12 is a schematic front view of the handle portion and its vicinity of the vehicle body shown in FIG. FIG. 13 is a schematic left side view showing the state in the vicinity of the operation transmission unit located inside the front cover when the slow forward speed lever is pulled. FIG. 14 is a schematic perspective view showing a state in which the operating arm shown in FIG. 13 is omitted. FIG. 15 is an enlarged perspective view of the empty box rack shown in FIG. FIG. 16 is a schematic left side view showing a state in the vicinity of the operation transmission unit when traveling is stopped according to another preferred embodiment of the present invention. 17 is a perspective view of the vicinity of the upper portion of the operation transmission unit shown in FIG. 16 as viewed from approximately the rear above. FIG. 18 is a schematic left side view showing a state in the vicinity of the operation transmission unit when the slow forward movement lever according to the embodiment shown in FIG. 16 is pulled slowly. FIG. 19 is a schematic left side view showing a state in the vicinity of the operation transmission unit when a quick pulling operation of the slow forward movement lever according to the embodiment shown in FIG. 16 is started. FIG. 20 is a schematic left side view showing the state in the vicinity of the operation transmission unit when the quick pulling operation of the slow forward movement lever according to the embodiment shown in FIG. 16 is completed. FIG. 21 is an enlarged perspective view of the brake pedal, the travel stop lever, and the vicinity thereof according to the embodiment shown in FIG. 22 is a schematic left side view showing a state in the vicinity of the operation transmission unit when the travel stop lever is pressed down in the embodiment shown in FIG. 16. FIG. FIG. 23 is a control block diagram of a rice transplanter according to still another preferred embodiment of the present invention. 24 is a schematic left side view of the vicinity of the speed change rod according to the embodiment shown in FIG. 23. FIG. FIG. 25 is a flowchart showing the control performed by the control unit to maintain the position of the aircraft. FIG. 26 is a schematic plan view of the rice transplanter according to the embodiment shown in FIG. 23 . FIG. 27 is a schematic side view of the first to third spare seedling frames shown in FIG. 26.

Below, a detailed description of a preferred embodiment of the present invention will be given with reference to the attached drawings.

Figure 1 is a schematic left side view of a rice transplanter 1 according to a preferred embodiment of the present invention, and Figure 2 is a schematic plan view of the rice transplanter 1 shown in Figure 1. Note that in Figure 1, an empty box rack 72, which will be described in detail later, is omitted for convenience.

Figure 3 is a control block diagram of the rice transplanter 1 shown in Figure 1.

In this specification, as shown by the arrows in Figures 1 and 2, the direction of travel of the rice transplanter 1 is referred to as the "front" and the opposite side is referred to as the "rear," and the left side facing the forward direction of travel of the rice transplanter 1 is referred to as the "left" and the opposite side is referred to as the "right."

The rice transplanter 1 is equipped with a traveling body 2, a seedling planting section 63 attached to the rear of the traveling body 2, a spare seedling frame 74 for storing spare seedlings to be supplied to the seedling planting section 63, a fertilizer applicator 26 for supplying fertilizer to the field, and a control section 87 for controlling the entire machine.

The traveling vehicle body 2 includes a main frame 3 located approximately in the center of the vehicle body 2, a rear frame 6 attached to the rear end of the main frame 3 and extending in the width direction of the rice transplanter 1, a link base frame 10 fixed to the rear frame 6, a floor step 60 located above the main frame 3, a driver's seat 48 located above the floor step 60, a control unit 49 for controlling the rice transplanter 1, an engine 7 located below the driver's seat 48, a pair of left and right front wheels 8 and a pair of left and right rear wheels 9 as traveling wheels, a power transmission mechanism 15 that transmits the rotational power output from the engine 7 to the pair of left and right front wheels 8 and rear wheels 9, and a front cover 47 that houses an operation transmission unit 32 (see Figure 6) described in detail later.

The steering section 49 includes a main speed change lever 35 that changes the forward/reverse movement and vehicle speed of the traveling body 2, a brake pedal 81 that stops the traveling of the traveling body 2, a steering mechanism 28 including a steering wheel 56 that steers the pair of left and right front wheels 8, a handle section 17 located at the front end of the body 2, a slow speed forward lever 36 that is located near the handle section 17 and is operated when moving the body 2 forward at a slow speed, and a travel stop lever 79 (see Figure 2) connected to the brake pedal 81. The travel stop lever 79 is a lever that stops the traveling of the body 2 while moving the body 2 forward at a slow speed by operating the slow speed forward lever 36.

The steering mechanism 28 includes a steering wheel 56, a steering shaft 83, a pitman arm, and a tie rod (not shown).

The power transmission mechanism 15 includes a belt-type power transmission mechanism 4 provided below the floor step 60 shown in FIG. 1, a power hydrostatic continuously variable transmission 25 that receives the rotational power transmitted by the belt-type power transmission mechanism 4, and a transmission case 30 that distributes and outputs the power output from the power hydrostatic continuously variable transmission 25 to the running wheels 8, 9 and the seedling planting section 63.

The rotational power output from the engine 7 is transmitted to the hydrostatic continuously variable transmission 25 via the belt-type power transmission mechanism 4, then the speed is changed within the hydrostatic continuously variable transmission 25 and transmitted to the transmission case 30. Hereinafter, the hydrostatic continuously variable transmission is referred to as "HST."

The rotational power transmitted to the transmission case 30 is divided inside the transmission case 30 into a driving power that drives a pair of front wheels 8 and a pair of rear wheels 9, and a working power that drives the seedling planting section 63. The transmission case 30 is fixed to the front of the main frame 3.

The driving power is transmitted to a pair of left and right front wheels 8 via a front wheel final case 13 and a front wheel axle 31, and also to a pair of rear wheels 9 via a pair of left and right rear wheel transmission shafts 14, a pair of left and right rear wheel gear cases 51, and a pair of left and right axles 82 shown in Figures 1 and 2. As a result, the traveling body 2 moves forward or backward.

Meanwhile, the power for work is transmitted to a planting clutch (not shown) provided at the rear of the traveling body 2, and when the planting clutch is engaged, it is further transmitted to the seedling planting section 63.

The planting clutch is switched on and off by the control unit 87 driving the planting clutch motor 27 based on the pressing of the planting on/off switch 19 (see Figure 3) provided on the main shift lever 35.

As shown in FIG. 1, the seedling planting section 63 is attached to the rear of the traveling body 2 so that it can rotate up and down by the lifting link device 5. The lifting link device 5 has an upper link arm 85 and a pair of lower link arms 86 on the left and right.

The front ends of the upper link arm 85 and the lower link arm 86 are attached to the link base frame 10 of the vehicle body 2, and the other ends are attached to the upper and lower link arms 11 located at the bottom of the seedling planting section 63.

When the electronic hydraulic valve 88 (see FIG. 3) is controlled by the control unit 87 and the lifting hydraulic cylinder 12 shown in FIG. 1 is hydraulically contracted, the upper link arm 85 is rotated upward and rearward, and the seedling planting unit 63 is raised to the non-working position. When the seedling planting unit 63 is in the non-working position, its lower end is positioned at approximately the same height as the bottom of the main frame 3.

In response to this, when the electronic hydraulic valve 88 is controlled by the control unit 87 and the lifting hydraulic cylinder 12 is hydraulically extended, the upper link arm 85 is rotated backward and downward, and the seedling planting unit 63 is lowered to a working position (see Figure 1) where seedlings can be planted.

The electronic hydraulic valve 88 is controlled based on the detection signal of the finger lever sensor 16 (see Figure 3), which detects the operation of a finger lever (not shown) attached to the main shift lever 35.

The seedling planting section 63 is equipped with a seedling placement table 65 on which mat-like seedlings with soil (hereinafter referred to as a "seedling mat") are placed, and a number of planting devices 64 provided behind and below the seedling placement table 65.

The multiple planting devices 64 are arranged in a line in the width direction of the rice transplanter 1, and each planting device 64 is equipped with two pairs of planting tools 69 arranged in the front-rear direction.

When the planting clutch is engaged and the drive shaft 67 shown in FIG. 1 is rotated, the front planting tool 69 and the rear planting tool 69 shown in FIGS. 1 and 2 rotate around the drive shaft 67, alternately removing seedlings located at the bottom end of the seedling placement table 65 and planting them in the field.

As shown in FIG. 2, in this embodiment, a total of four rows of planting tools 69 are arranged in the left-right direction, so that when the rice transplanter 1 travels straight ahead while planting seedlings in the field, four rows of seedlings are formed in the field.

The left and right spare seedling frames 74 are attached to the vehicle body 2 via support frames 77 shown in Figures 1 and 2.

The control unit 87 includes a processing unit 91 having a CPU (Central Processing Unit) and a memory unit 92 having a ROM (Read Only Memory) and a RAM (Random Access Memory) (see FIG. 3). The memory unit 92 stores various programs and data that control the entire rice transplanter 1.

Figure 4 is a schematic plan view showing the operating range of the main shift lever 35 shown in Figure 1, Figure 5 is a schematic left side view showing the vicinity of the base end 35b of the main shift lever 35 located inside the front cover 47 shown in Figure 1, and Figure 6 is a schematic left side view showing the state near the operation transmission unit 32 located inside the front cover 47 when driving is stopped.

Figure 6 shows the main transmission arm 33, the operation transmission part 32, and the transmission rod 34 when the vehicle body 2 is stopped (neutral state).

Figure 7 is a drawing showing the vicinity of HST25, where Figure 7(a) is a schematic explanatory diagram of the vicinity of HST25, Figure 7(b) is a schematic left side view of the vicinity of HST25, and Figure 7(c) is a schematic plan view of the vicinity of HST25.

The steering section 49 is provided with a lever panel 77 that defines the operating range of the main shift lever 35 (see FIG. 4). The lever panel 77 is provided with an opening 78 that is formed along the operating range of the main shift lever 35, and the forward/reverse lever 20 is operated forward/backward and left/right along the shape of the opening 78 while passing through the opening 78.

The operating range of the main shift lever 35 includes a forward region where the traveling body 2 moves forward, a neutral region where the traveling body 2 stops, and a reverse region where the traveling body 2 moves backward.

When the main shift lever 35 is located in the forward range, the further forward the main shift lever 35 is operated, the higher the forward vehicle speed is adjusted. Also, when the main shift lever 35 is located in the reverse range, the further rearward the main shift lever 35 is operated, the higher the reverse vehicle speed is adjusted.

A main shift arm 38 is attached to the lower front base end 35b of the main shift lever 35.

When the main shift lever 35 is operated forward, the main shift arm 38 is swung forward and downward about the swing fulcrum 39, and the main shift rod 33 (see Figures 5 and 6) connected to the front of the main shift arm 38 is moved downward. A neutral return plate 93 is attached to the main shift arm 38, and when the brake pedal 81 is depressed, the main shift arm 38 is swung by the neutral return plate 93, and the main shift lever 35 is returned to the neutral region.

When the main shift lever 35 is operated forward and the main shift rod 33 is moved downward, the operation of the operation transmission unit 32 (see Figure 6), which will be described in detail later, causes the shift rod 34 (see Figures 6 and 7) connected to the HST 25 to move (slide) rearward (see Figure 9).

In contrast, when the main speed change lever 35 is operated rearward, the main speed change arm 38 is swung upward toward the front around the swing fulcrum 39, and the main speed change rod 33 is moved upward.

When the main speed-change rod 33 is moved upward, the operation of the operation transmission unit 32 shown in FIG. 6 causes the speed-change rod 34 connected to the HST 25 to move (slide) forward (see FIG. 10).

In other words, when the main shift lever 35 is operated to the neutral region and the traveling vehicle body 2 is stopped, if the main shift lever 35 is operated to the forward region, the shift rod 34 is moved backward, and if the main shift lever 35 is operated to the reverse region, the shift rod 34 is moved forward.

The rear end of the speed change rod 34 is attached to the tip of the trunnion arm 25c of the HST 25, as shown in Figures 7(a) and 7(c). When the speed change rod 34 is moved forward or backward with the main speed change lever 35 being operated forward or backward, the trunnion shaft 25a connected to the base end of the trunnion arm 25c is rotated.

The trunnion shaft 25a is connected to the movable swash plate 25d of the HST 25 shown in FIG. 7(a). When the trunnion shaft is rotated, the inclination angle of the movable swash plate 25d changes, which changes the rotation speed of the output shaft 25g shown in FIG. 7(a) and FIG. 7(c).

In detail, when the input shaft 25b to the HST 25 rotates due to the operation of the engine 7, the variable displacement hydraulic pump 25e shown in FIG. 7(a) is rotated.

At this time, if the speed change rod 34 is moved from the neutral region where the vehicle body 2 is stopped to the forward (rear) or reverse (forward) side, an amount of oil according to the inclination angle of the movable swash plate 25d is discharged from the hydraulic pump 25e.

The oil discharged from the hydraulic pump 25e is supplied to the hydraulic motor 25f through the hydraulic circuit 25h shown in FIG. 7(a), and the output shaft 25g of the HST 25 is rotated by the hydraulic motor 25f.

The rotation of the output shaft 25g is in the opposite direction when the vehicle body 2 moves forward and backward, and the rotation speed of the output shaft 25g changes continuously depending on the inclination angle of the movable swash plate 25d, i.e., the fore-aft position of the speed change rod 34.

In contrast, when the main shift lever 35 is operated to the neutral region and the shift rod 34 is in a neutral position in the fore-and-aft direction (see FIG. 6), even if the hydraulic pump 25e rotates in conjunction with the rotation of the input shaft 25b to the HST 25, no oil is discharged from the hydraulic pump 25e. Therefore, the output shaft 25g of the HST 25 does not rotate, and the traveling vehicle body 2 does not travel.

The above describes in detail how the output of the HST 25 changes when the main shift lever 35 is operated forward or backward. The shift rod 34 is moved forward or backward by the operation transmission unit 32 in response to the forward or backward operation of the main shift lever 35 as follows.

6, the operation transmission unit 32 includes a positioning mechanism 41 to which the lower end of the main speed-change rod 33 and the front end of the speed-change rod 34 are attached, a stay 66 fixed to an inner-cover frame 40 provided in the front cover 47, a cam 46 that rotates around a cam rotation shaft 46a fixed to the stay 66, an operating arm 42 connected to the cam 46 by a first cam pin 59, and a switching arm 43 connected to the operating arm 42 by a moving pin 44. A long hole 42a is formed in the rear of the operating arm 42, and the first cam pin 59 is inserted into the long hole 42a.

Figure 8 (a) is an exploded perspective view of the positioning mechanism 41 shown in Figure 6, Figure 8 (b) is an enlarged side view of the cutout window 41b1 of the positioning mechanism 41, and Figure 8 (c) is an enlarged side view of the long hole 41c of the positioning mechanism 41.

Figure 8 (c) shows the relative positions of the long hole 41c and the movable pin 44, which will be described in detail later.

The positioning mechanism 41 includes a main plate 41a and a sub-plate 41b that are connected to each other, and a spring 50 that connects the main plate 41a and the sub-plate 41b and biases the sub-plate 41b to rotate clockwise (in FIG. 6).

The main plate 41a is formed with an approximately inverted Y-shaped long hole 41c into which the moving pin 44 is inserted, a mounting hole 52 to which one end of the spring 50 is attached, two insertion holes 54 and 55, and a mounting hole 57 to which the lower end of the main speed change rod 33 is attached.

The approximately inverted Y-shaped long hole 41c has an arc-shaped portion 41c1 that extends in an arc shape in FIG. 8(c), and a notch portion 41c2 that extends approximately upward so as to branch off from approximately the center of the arc-shaped portion 41c1.

A cylindrical main pivot shaft 41a1 fixed to the cover inner frame 40 is inserted into the two insertion holes 54, 55. A cylindrical first connecting member 41a2 is attached to the lower part of the main plate 41a below the insertion hole 55.

The sub-plate 41b is formed with an attachment hole 53 to which the other end of the spring 50 is attached, a cutout window 41b1 into which the main pivot shaft 41a1 is inserted, and an attachment hole 58 to which the front end of the speed change rod 34 is attached. The sub-plate 41b is also formed with a second connecting member 41b2 that is inserted into the first connecting member 41a2.

The main plate 41a and the sub-plate 41b are connected by a spring 50, and can rotate together around the main rotation shaft 41a1 when the second connecting member 41b2 is inserted into the first connecting member 41a2.

The cutout window 41b1 formed in the secondary plate 41b has a main pivot shaft insertion portion 41b1a into which the main pivot shaft 41a1 is inserted, and a pin insertion portion 41b1b into which the slow forward drive pin 62 fixed to the lower end of the actuating arm 42 is inserted.

As shown in FIG. 8(b), the main pivot shaft insertion portion 41b1a is formed larger than the main pivot shaft 41a1, and is configured so that a play space S is created even when the main pivot shaft 41a1 is inserted.

Therefore, even when the main plate 41a is not moving or rotating, the sub-plate 41b can rotate (independently from the main plate 41a) around the first connecting member 41a2 and the second connecting member 41b2 by the amount of the play space S.

When the main shift lever 35 is in the neutral region (in other words, when the vehicle body 2 is stopped), the moving pin 44 inserted into the approximately inverted Y-shaped long hole 41c is located at position 44a within the arc-shaped portion 41c1 shown in FIG. 8(c).

On the other hand, the switching arm 43 is attached to the stay 66 by a switching arm pivot shaft 45 and is configured to be able to swing around the switching arm pivot shaft 45. A coil spring (not shown) is housed inside the switching arm pivot shaft 45, and the switching arm 43 is biased to swing counterclockwise in FIG. 6 by this coil spring.

A switching arm pin 43a is attached to the rear end of the switching arm 43.

The switching arm pin 43a abuts against the periphery of the cam 46, and is located within a recess (depression) 46c (see FIG. 13) formed in the cam 46 when the main shift lever is in neutral (when the vehicle is not traveling) as shown in FIG. 6. In addition, a protrusion 46b is formed below the recess 46c of the cam 46 (see FIG. 13).

For this reason, when the main shift lever is in the neutral position, the cam 46 is urged to rotate counterclockwise by the switching arm pin 43a, which presses the recessed portion 46c substantially upward.

In light of the above, the operation of the operation transmission unit 32 when the main shift lever 35 is operated to the forward or reverse range will be described in detail below.

Figure 9 is a schematic left side view showing the state near the operation transmission unit 32 when the main shift lever 35 is operated to the forward range, and Figure 10 is a schematic left side view showing the state near the operation transmission unit 32 when the main shift lever 35 is operated to the reverse range.

When the main speed change lever 35 is operated from the neutral region shown in FIG. 4 to the forward region and the main speed change rod 33 is moved downward, the positioning mechanism 41 including the main plate 41a is rotated counterclockwise (as viewed from the left side) as a unit around the main pivot shaft 41a1.

As a result, the speed change rod 34 attached to the lower part of the sub-plate 41b is moved rearward, and the output shaft 25g of the HST 25 is rotated in the direction in which the vehicle body 2 moves forward.

At this time, as the positioning mechanism 41 including the main plate 41a rotates counterclockwise, the moving pin 44 is positioned at position 44b within the arc-shaped portion 41c1 shown in FIG. 8(c).

In contrast, when the main shift lever 35 is operated from the neutral region shown in FIG. 4 to the reverse region and the main shift rod 33 is moved upward, the positioning mechanism 41 including the main plate 41a rotates clockwise (as viewed from the left side) as a unit around the main pivot shaft 41a1.

As a result, the speed change rod 34 attached to the lower part of the sub-plate 41b is moved forward, and the output shaft 25g of the HST 25 is rotated in the direction in which the vehicle body 2 moves backward.

At this time, as the positioning mechanism 41 including the main plate 41a rotates counterclockwise, the moving pin 44 is positioned at position 44c within the arc-shaped portion 41c1 shown in FIG. 8(c).

The movement of the operation transmission unit 32 when the main speed change lever 35 is operated has been described above in detail. When moving the rice transplanter 1 in and out of the field, the operator can operate the slow-speed forward lever 36, which will be described in detail below, from the front of the rice transplanter 1 to move the rice transplanter 1 forward at a slow speed and get it over the edge of the field. As will be described in detail later, the slow-speed forward lever 36 can only be operated when the main speed change lever 35 is in the neutral zone. Therefore, the following description will be given on the assumption that the main speed change lever 35 is in the neutral zone.

Figure 11 is a schematic perspective view of the vicinity of the traveling body 2 shown in Figure 1, and Figure 12 is a schematic front view of the vicinity of the handle portion 17 of the traveling body 2 shown in Figure 1.

Figure 13 is a schematic left side view showing the state near the operation transmission unit 32 located inside the front cover 47 when the slow forward lever 36 is pulled, and Figure 14 is a schematic perspective view showing the state in which the operating arm 42 shown in Figure 13 is omitted.

Note that for convenience, the brake pedal 81 and the travel stop lever 79 are omitted from FIG. 12.

The handle portion 17 has a generally inverted U-shape when viewed from the front (see FIG. 12) and in a plan view (see FIG. 2), and includes a horizontal extension portion 17a that extends generally horizontally in the left-right direction, and curved portions 17b that extend from both the left and right ends of the horizontal extension portion 17a to the floor step 60.

As shown in FIG. 2, the horizontal extension section 17a is located forward of the center mascot 18, which indicates the position of the widthwise center of the rice transplanter 1.

The slow forward movement lever 36 is fixed to the underside of the horizontal extension 17a of the handle portion 17.

The slow-speed forward lever 36 is configured so that when it is pulled (more specifically, swung upward to the right around the fulcrum 36c) like a brake lever on a typical bicycle, the inner wire 70 connected to the slow-speed forward lever 36 is pulled toward the lever 36.

The inner wire 70 extends inside the outer wire 71 shown in FIG. 12, with one end attached to the slow forward lever 36 and the other end attached to the cam first pin 59 shown in FIGS. 6, 13, 14, etc.

Therefore, when the slow forward movement lever 36 is pulled and the inner wire 70 is pulled toward the lever 36, the first cam pin 59 is moved substantially downward.

Since the first cam pin 59 is attached to the cam 46 and the operating arm 42, the movement of the first cam pin 59 causes the cam 46 to rotate clockwise around the cam rotation shaft 46a in Figures 6 and 13.

When the cam 46 is rotated, the switching arm pin 43a, which was located in the recessed portion 46c of the cam 46, is pushed substantially downward by the corner 46c1 (see FIG. 13) of the recessed portion 46c, and then moves away from the corner 46c1 and is held in the vertical position shown in FIG. 14. Note that this vertical position is lower than the position of the switching arm pin 43a shown in FIGS. 6, 9, and 10.

As a result, the switching arm 43 rotates clockwise around the switching arm rotation shaft 45 as viewed from the left side in conjunction with the clockwise rotation of the cam 46. This causes the moving pin 44 to move substantially forward and upward, that is, to position 44d within the cutout portion 41c2 shown in FIG. 8(c).

At this time, the approximately vertical center of the operating arm 42 connected to the moving pin 44 also moves approximately forward and upward. In addition, as the first cam pin 59 moves, the rear part of the operating arm 42 is pulled approximately downward, so that the operating arm 42 as a whole swings clockwise in FIG. 13, and the slow forward drive pin 62 fixed to the lower end of the operating arm 42 moves approximately forward.

As a result, the inner surface of the front part of the pin insertion part 41b1b is pressed substantially forward by the slow forward drive pin 62, and the sub-plate 41b is rotated counterclockwise in a left side view around the first connecting member 41a2 and the second connecting member 41b2, against the biasing direction of the spring 50.

Therefore, when the slow forward lever 36 is pulled, the lower part of the sub-plate 41b is moved rearward, which in turn moves the speed change rod 34 rearward, so that, as described above, rotational power is output from the HST 25 and the traveling vehicle body 2 moves forward.

When the sub-plate 41b is rotated counterclockwise, the main rotation shaft 41a1 comes into contact with the rear surface 41b12 of the main rotation shaft insertion portion 41b1a of the cutout window 41b1 formed in the sub-plate 41b, as shown in FIG. 8(b).

At this time, the main shift lever 35 is in the neutral region, so the main plate 41a does not move, and the rotation of the sub-plate 41b is restricted midway by the rear surface 41b12 of the main pivot shaft insertion portion 41b1a.

In this way, the cutout window 41b1 limits the amount of rotation of the sub-plate 41b to the range of the play space S, and limits the amount of rearward movement of the shift lever 35, so that the forward travel speed of the traveling vehicle body 2 when the slow speed forward lever 36 is pulled is suppressed to a slow speed. In other words, when the slow speed forward lever 36 is pulled, a rotational power is output from the HST 25 at a rotational speed sufficient to move the vehicle body 2 forward at a slow speed.

Therefore, while the operator is outside the rice transplanter 1, he or she can pull the slow forward lever 36 from the front of the rice transplanter 1 to move the rice transplanter 1 forward at a slow speed and cross the edge of the field.

In this embodiment, the speed of the traveling vehicle body 2 when the slow forward lever is pulled (in other words, gripped) is 2 km/h or less.

The slow-speed forward movement lever 36 is configured to be swung upward and to the right around the fulcrum 36c only while it is being pulled, like a typical bicycle brake lever, and when the operator releases it, a spring (not shown) returns the slow-speed forward movement lever 36 to its original position.

At this time, the operating arm 42 rotates counterclockwise when viewed from the left side due to its own weight, and as the first cam pin 59 moves upward, the cam 46 rotates counterclockwise.

As a result, the switching arm pin 43a attached to the rear end of the switching arm returns into the recessed portion 46c.

On the other hand, as described above, when the main shift lever 35 is in the neutral region, that is, when the moving pin 44 is in the position 44a shown in FIG. 8(c), if the slow forward lever 36 is pulled, the moving pin 44 is moved into the notch portion 41c2.

However, when the main shift lever 35 is in the forward or reverse range, i.e., when the moving pin 44 is in the position 44b or 44c shown in FIG. 8(c), if the slow forward lever 36 is pulled, the movement of the moving pin 44 in the approximately upward direction is restricted by the arc-shaped portion 41c1.

Therefore, in this embodiment, when the main shift lever 35 is in the forward or reverse range, the vehicle body 2 cannot be moved forward at a slow speed by pulling the slow forward lever 36.

As shown in FIG. 12, the slow forward movement lever 36 is fixed to the underside of the horizontal extension 17a of the handle portion 17, which extends substantially horizontally in the left-right direction, and is positioned rearward of the front end 17a1 of the handle portion 17 (see FIG. 1). In other words, the slow forward movement lever 36 is positioned below the upper end 17a2 of the handle portion 17 and rearward of the front end 17a1 of the handle portion 17.

In this way, since the slow-speed forward lever 36 is located below the upper end 17a2 of the handle portion 17, even if the operator stands in front of the rice transplanter 1 and accidentally trips and falls forward while operating the slow-speed forward lever 36 located near the handle portion 17, the operator is unlikely to come into contact with the slow-speed forward lever 36. This prevents the rice transplanter 1 from continuing to move forward if the operator trips and falls over the handle portion 17, ensuring safety.

In addition, because the slow-speed forward lever 36 is located behind the front end 17a1 of the handle portion 17, even if the operator is caught between the front end of the rice transplanter 1 and an obstacle located in front of the rice transplanter 1, the operator is unlikely to come into contact with the slow-speed forward lever 36.

This prevents the slow-speed forward movement lever 36 from being pulled unintentionally (in other words, the slow-speed forward movement lever 36 from being pinched and mechanically locked), ensuring safety.

Furthermore, because the slow-speed forward lever 36 does not extend forward from the handle portion 17, even if the rice transplanter 1 is equipped with the slow-speed forward lever 36, the overall length of the rice transplanter 1 can be kept small, and therefore the rice transplanter 1 does not take up much space when loaded onto a truck or the like.

Figure 15 is an enlarged perspective view of the empty box rack 72 shown in Figure 11.

As shown in Figures 11 and 15, an empty box rack 72 for storing empty seedling boxes is located above the spare seedling frame 74 on the right side.

This empty box rack 72 includes a mounting frame 72a attached to the spare seedling frame 74, a square pipe 72b fixed to the top surface of the mounting frame 72a, a pair of front and rear plates 72c fixed to the front and rear ends of the square pipe 72b, a main frame body 72d welded to the right surface of the pair of plates 72c, a sub-frame body 72e welded to straddle the front and rear ends of the main frame body 72d, a pair of front and rear rail support frames 72f welded to straddle the main frame body 72d and the sub-frame body 72e, a rail member 72g supported by the rail support frame 72f, and a first storage section 73 and a second storage section 75 for storing empty seedling boxes.

The main frame 72d has a pair of front and rear left and right extension parts 72d1 that extend in the left-right direction (aircraft width direction), a pair of left and right front and rear extension parts 72d2 that extend in the front-rear direction to connect the pair of left and right extension parts 72d1, and a pair of front and rear connectors 72d3 that extend to connect the right front and rear extension part 72d2 to the pair of plates 72c.

As shown in FIG. 15, the first storage section 73 is surrounded on the right side by the right front-to-rear extension section 72d2, on the left side by the sub-frame body 72e, on the front and rear sides by the right parts of the pair of left-to-right extension sections 72d1, and on the bottom by the right parts of the pair of front and rear plates 72c.

The empty seedling box placed in the first storage section 73 is supported by the right parts of the pair of plates 72c in an upright position so that it extends roughly vertically (in other words, the seedling box is in an upright position), and is leaned against the left face of the right front-rear extension section 72d2 or the right face of the sub-frame body 72e.

As shown in FIG. 15, the second storage section 75 is surrounded on the left side by the left front-rear extension section 72d2, on the right side by the sub-frame body 72e, on the front and rear sides by the left parts of the pair of left-right extension sections 72d1, and on the bottom by the rail member 72g.

Empty seedling boxes placed in the second storage section 75 are supported by the rail member 72g in an upright position extending in a generally vertical direction, and are leaned against the right face of the left front-rear extension section 72d2 or the left face of the sub-frame body 72e.

As shown in FIG. 15, each of the left and right front-rear extensions 72d2 and sub-frames 72e is generally U-shaped in side view, and the pair of front-rear left-right extensions 72d1 is configured lower than the pair of left-right front-rear extensions 72d2 and sub-frames 72e. In other words, the pair of front-rear left-right extensions 72d1 is positioned lower than the pair of left-right front-rear extensions 72d2 and sub-frames 72e.

Therefore, when an operator stands on the rice transplanter 1 and stores empty seedling boxes in the first or second storage section 73, 75 from the rear side of the empty box rack 72, or when an operator stands in front of the rice transplanter 1 (outside the machine) and retrieves empty seedling boxes from the first or second storage section 73, 75 from the front side of the empty box rack 72, the pair of front and rear left and right extension sections 72d1 do not get in the way, making it easy to insert and remove seedling boxes from the empty box rack 72.

In addition, a rail member 72g is provided below the second storage section 75, so the worker can slide an empty seedling box into the second storage section 75.

In contrast, the first storage section 73 does not have a rail member installed below it, so workers can place seedling boxes soiled with mud or the like into the first storage section 73 to drain off the mud and water.

The front and rear ends of the square pipe 72b are covered by a pair of plates 72c, and drainage holes 72c1 are formed in the parts of each plate 72c that come into contact with the square pipe 72b.

In this embodiment, the seedling box rack 72 configured as described above is provided only above the spare seedling frame 74 on the right side, but a seedling box rack 72 may be provided above each of the spare seedling frames 74 on the left and right sides. Also, it is not necessarily necessary to provide the sub-frame body 72e and a pair of rail support frames 72f on the empty box rack 72.

Figure 16 is a schematic left side view showing the state of the vicinity of the operation transmission unit 32' when the vehicle is stopped (= main shift lever 35 is in the neutral region) according to another preferred embodiment of the present invention, and Figure 17 is a perspective view of the vicinity of the upper part of the operation transmission unit 32' shown in Figure 16, viewed from approximately the rear above.

In Figures 16 and 17, the operating arm 42' and main plate 41a are drawn semi-transparently to show the shape of the switching arm 43'.

The rice transplanter 1000 according to this embodiment is configured similarly to the rice transplanter 1 according to the embodiment shown in Figures 1 to 15, except for the points described below. In the following, the parts configured similarly to the rice transplanter 1 according to the embodiment are denoted by the same reference numerals and will not be described.

In the operation transmission unit 32' according to this embodiment, a coil spring (torque spring) 68 (see FIG. 17) is arranged on the cam pivot shaft 46a', which is the pivot point of the cam 46', instead of the switching arm pivot shaft 45', which is the pivot point of the switching arm 43'.

The cam 46' is biased by a coil spring 68 to rotate counterclockwise around the cam rotation shaft 46a' when viewed from the left side. In addition, the cam 46' does not have a recessed portion 46c.

The rear end of the switching arm 43' does not have a switching arm pin 43a, and as shown in FIG. 17, the rear end of the switching arm 43' is curved to the right, and the rear end of the switching arm 43' is supported from below by the protrusion 46b of the cam 46'.

Therefore, when the cam 46' rotates counterclockwise, the switching arm 43' rotates upward toward the rear in tandem.

The switching arm 43' has a protrusion 43b that protrudes upward at approximately the center in the front-to-rear direction, and this protrusion 43b is connected to the upper part of the cam 46' by a spring 76.

The operating arm 42' is longer at the rear than in the previous embodiment, and is attached to the rear end of the cam 46' by the first cam pin 59.

In this embodiment, the inner wire 70, which is pulled by pulling the slow forward lever 36, is attached to a second cam pin 80 fixed to the cam 46'. The second cam pin 80, like the first cam pin 59, is positioned rearward of the cam pivot shaft 46a', and when the slow forward lever 36 is pulled, the cam 46' is rotated clockwise.

The cutout window 41b1' of the sub-plate 41b' has a main pivot shaft insertion portion 41b1a into which the main pivot shaft 41a1 is inserted, a pin insertion portion 41b1b into which the slow forward drive pin 62 fixed to the lower end of the actuating arm 42 is inserted, and a non-acting portion 41b1c.

The non-acting portion 41b1c is a cutout area through which the slow forward drive pin 62 moves when the slow forward lever 36 is gripped quickly (more specifically, pulled at a predetermined operating speed or faster).

The main plate 41a is configured in the same way as in the previous embodiment, and when the main shift lever 35 is operated back and forth, the positioning mechanism 41' is rotated in the same way, the shift rod 34 is moved back and forth, and the output of the HST 25 is started, stopped, or changed.

Figure 18 is a schematic left side view showing the state near the operation transmission unit 32' when the slow forward lever 36 in the embodiment shown in Figure 16 is pulled slowly.

Figure 19 is a schematic left side view showing the state near the operation transmission unit 32' when the slow forward movement lever 36 according to the embodiment shown in Figure 16 is started to be pulled quickly, and Figure 20 is a schematic left side view showing the state near the operation transmission unit 32' when the slow forward movement lever 36 according to the embodiment shown in Figure 16 is completed.

In this embodiment, when the slow-speed forward movement lever 36 is pulled slowly (more specifically, at a speed slower than a predetermined operating speed) by the operator, the traveling vehicle body 2' moves forward at a slow speed, and when the slow-speed forward movement lever 36 is pulled quickly (more specifically, at a speed faster than the predetermined operating speed), the traveling vehicle body 2' does not move forward.

Specifically, when the main shift lever 35 is in the neutral region (see FIG. 16) and the slow forward lever 36 (see FIG. 12) is pulled slowly, the inner wire 70 is pulled toward the lever 36, and the first cam pin 59 is moved slowly substantially downward (see FIG. 18). This causes the cam 46' to rotate slowly clockwise when viewed from the left side.

At this time, the spring 76 connecting the switching arm 43' and the cam 46' is moved slowly rearward without being significantly stretched, and the switching arm 43' is pulled by the spring 76 and rotated clockwise around the switching arm rotation shaft 45' when viewed from the left side.

As a result, the movable pin 44 attached to the front of the switching arm 43' is moved substantially upward and switches from position 44a shown in FIG. 8(c) to position 44d within the cutout portion 41c2.

At the same time, as the cam 46' rotates, the operating arm 42' rotates clockwise in left side view around the moving pin 44 located in the cutout portion 41c2.

As a result, the front surface of the pin insertion portion 41b1b is pressed substantially forward by the slow forward drive pin 62 fixed to the lower end of the actuating arm 42', and the sub-plate 41b' is rotated counterclockwise in left side view around the first connecting member 41a2 and the second connecting member 41b2.

When the slow forward lever 36 is operated, the main speed change lever 35 is in the neutral region, so the main plate 41a does not move, and the main pivot shaft 41a1 comes into contact with the rear surface 41b12 of the main pivot shaft insertion portion 41b1a of the cutout window 41b1, restricting the rotation of the sub-plate 41b' midway.

In other words, the rotation of the secondary plate 41b' is limited within the range of the play space S shown in FIG. 8(b), as in the previous embodiment.

For details about the first connecting member 41a2 and the second connecting member 41b2, please refer to Figure 18 or Figure 8 (a).

As a result of the secondary plate 41b' being rotated a predetermined amount in this manner, the speed change rod 34 is moved slightly rearward from the position shown in FIG. 16 to the position shown in FIG. 18, as in the previous embodiment, and the traveling vehicle body 2' moves forward at a slow speed.

In contrast, when the slow forward movement lever 36 is pulled quickly, the first cam pin 59 is quickly moved substantially downward, and the cam 46' is quickly rotated clockwise when viewed from the left side.

At this time, the spring 76 is significantly stretched due to the inertial force of the switching arm 43', and the rotation of the switching arm 43' about the switching arm pivot shaft 45' begins later than when the slow forward lever 36 is pulled slowly.

At the same time, as the cam 46' rotates quickly, the operating arm 42', whose rear end is attached to the cam 46', rotates quickly clockwise around the moving pin 44 when viewed from the left side.

Due to the delay in starting to rotate the switching arm 43', the operating arm 42' is quickly rotated before the moving pin 44 moves from the position shown as 44a in FIG. 8(c) into the notch portion 41c2.

As a result, the slow forward drive pin 62 fixed to the lower end of the operating arm 42' is moved from the position shown in FIG. 16 to the position shown in FIG. 19 by the rotation of the operating arm 42', and then moved to the non-acting portion 41b1c as shown in FIG. 20.

In other words, when the moving pin 44, which is the pivot point of the operating arm 42', has not risen to the notch 41c2, the slow forward drive pin 62 is rotated around the moving pin 44, so it is moved into the non-acting portion 41b1c rather than into the pin insertion portion 41b1b.

The non-acting portion 41b1c extends forward from the bottom of the pin insertion portion 41b1b, so the slow forward drive pin 62 does not press forward against the front surface of the non-acting portion 41b1c.

As a result, the sub-plate 41b' does not rotate, the speed-change rod 34 does not move, and the traveling vehicle body 2' does not move forward.

In this manner, in this embodiment, when the slow-speed forward movement lever 36 is pulled at high speed, the spring 76, which is an example of the "transmission prevention means" of the present invention, is significantly stretched. Therefore, the rotation of the switching arm 43' about the switching arm rotation shaft 45' begins later than when the slow-speed forward movement lever 36 is pulled slowly. As a result, while the moving pin 44 has not moved into the notch portion 41c2, the slow-speed forward movement drive pin 62 has moved into the non-acting portion 41b1c, and the secondary plate 41b' is not rotated counterclockwise in the left side view, so the traveling vehicle body 2' does not move forward.

This prevents the traveling vehicle body 2' from suddenly and unintentionally starting off if, for example, an operator accidentally touches the slow forward lever 36.

The slow-speed forward movement lever 36 has been described in detail above, but in this embodiment, the slow-speed forward movement lever 36 is pulled and the travel stop lever 79 located at the front of the vehicle body 2' is pushed down to stop the traveling vehicle body 2' as follows.

Figure 21 is an enlarged perspective view of the vicinity of the brake pedal 81 and the travel stop lever 79 in the embodiment shown in Figure 16, and Figure 22 is a schematic left side view showing the state in the vicinity of the operation transmission unit 32' when the travel stop lever 79 is depressed in the embodiment shown in Figure 16.

In Figure 21, the front cover 47 and floor step 60 are omitted for ease of explanation.

The brake pedal 81 and the travel stop lever 79 are connected by a link rod 84.

The travel stop lever 79 is positioned facing forward, and when the operator presses it down (more specifically, rotates it forward and downward), the brake pedal 81 is pressed down in tandem.

When the brake pedal 81 is depressed, a brake device (not shown) provided inside the transmission case 30 is activated, braking the pair of front wheels 8 and the pair of rear wheels 9.

The brake device that brakes the running wheels 8, 9 can be configured to be activated by a motor or solenoid when a sensor detects the depression of the brake pedal 81, or it can be configured to transmit the depression of the brake pedal 81 to the brake device via a mechanical mechanism, like a typical bicycle brake, to activate the brake device.

When the brake pedal 81 is pressed down, the brake stay 89 attached to the brake pedal 81 and the brake shaft 90 welded to the upper end of the brake stay 89 are rotated clockwise when viewed from the left side (counterclockwise when viewed from the right side).

A neutral return plate 93' shown in Figures 16, 18, 19, 21 and 22 is attached to the left end of the brake shaft 90, and as the brake shaft 90 rotates, the neutral return plate 93' rotates clockwise when viewed from the left side. Note that these movements when the travel stop lever 79 is pressed down are indicated by thick arrows in Figure 21.

As shown in Figures 21 and 22, a stopper 94 is fixed to the neutral return plate 93'. Therefore, when the neutral return plate 93' is rotated by pressing down the travel stop lever 79, the stopper 94 is rotated clockwise as viewed from the left side about the rotation fulcrum 94b and moved forward.

The front lower part of the stopper 94 is formed with an inclined portion 94a that slopes upward toward the front.

When the stopper 94 is moved forward with the moving pin 44 positioned in the notch 41c2 by pulling the slow forward lever 36 (see FIG. 18), the inclined portion 94a shown with diagonal lines in FIG. 22 comes into contact with the hub 95 attached to the left of the moving pin 44. The hub 95 is shown in FIG. 22 as well as in FIG. 17, FIG. 21, etc.

As a result of the inclined portion 94a coming into contact with the hub 95, the moving pin 44 is pushed down to the position 44a (see also FIG. 8(c)) within the arc-shaped portion 41c1 as shown in FIG. 22. As a result, the slow forward drive pin 62, which was located within the pin insertion portion 41b1b before the travel stop lever 79 was pushed down, is moved to the non-acting portion 41b1c.

As a result, the sub-plate 41b' returns to the position it had before it was rotated by pulling the slow forward lever 36 (see FIG. 16). As a result, the speed change rod 34 attached to the lower part of the sub-plate 41b' is moved forward from the fore-and-aft position where the body 2' moves forward slowly to the fore-and-aft position where the body 2' stops, and the output of the driving power of the HST 25 is stopped.

In this embodiment, when the slow-speed forward movement lever 36 is pulled and the travel stop lever 79 is pushed down, the traveling wheels 8 and 9 are braked and the output of the traveling power of the HST 25 is stopped, taking precedence over the slow-speed forward movement operation by the slow-speed forward movement lever 36. As a result, the traveling vehicle body 2' immediately stops.

With this configuration, when the operator moves the rice transplanter 1000 over the field ridge and takes it in and out of the field, he or she can move the rice transplanter 1000 forward at a slow speed by pushing down the handle portion 17 and pulling the slow forward lever 36, and when he or she wants to stop the rice transplanter 1000, he or she can push down the travel stop lever 79 to stop it. Therefore, the rice transplanter 1000 can be safely and easily taken in and out of the field.

Normally, the vehicle body 2' is moved forward at a slow speed by operating the slow-speed forward lever 36 when the vehicle is moving in and out of a field, so the planting clutch is turned off. Therefore, the power output from the HST 25 when the slow-speed forward lever 36 is operated is normally transmitted only to the working power wheels 8, 9, and not to the seedling planting section 63.

In addition, since the slow-speed forward lever 36 is operated to swing upward to the right near the handle section 17, it is desirable for the operator to stand in front of the rice transplanter 1000, pull the slow-speed forward lever 36 while pushing down the handle section 17 with the right hand, and when stopping the rice transplanter 1000, push down the travel stop lever 79 with the left hand. This allows the rice transplanter 1000 to be easily operated to move forward or stop.

Furthermore, the travel stop lever 79 is configured to return to the position it had before being pushed down when the lock release lever 98 shown in Figures 18, 21, etc. is pulled upward.

Therefore, the operator can operate the travel stop lever 79 to stop the rice transplanter 1000, and then operate the lock release lever 98 and further pull the slow-speed forward movement lever 36 to resume the slow-speed forward movement of the rice transplanter 1000.
<Technical significance of the second embodiment>
According to this embodiment shown in Figures 16 to 22, as in the previous embodiment, as shown in Figures 2 and 12, the slow-speed forward lever 36 is located below the upper end 17a2 of the handle portion 17, so that even if an operator stands in front of the rice transplanter 1000 and stumbles and falls forward while operating the slow-speed forward lever 36 provided near the handle portion 17, the operator is unlikely to come into contact with the slow-speed forward lever 36. Therefore, it is possible to prevent the rice transplanter 1000 from continuing to move forward in a state where the operator stumbles and falls over the handle portion 17, which is safe.

Furthermore, according to this embodiment, as in the previous embodiment, as shown in FIG. 1, the slow-speed forward lever 36 is located rearward of the front end 17a1 of the handle portion 17, so that even if the operator is caught between the front end of the rice transplanter 1000 and an obstacle located in front of the rice transplanter 1000, the operator is unlikely to come into contact with the slow-speed forward lever 36. Therefore, it is possible to prevent the slow-speed forward lever 36 from coming into contact with the operator and being held in a pulled state, which is safe.

In addition, according to this embodiment, the slow-speed forward lever 36 does not protrude forward from the handle portion 17, so even if the rice transplanter 1000 is equipped with the slow-speed forward lever 36, the overall length of the rice transplanter 1000 can be reduced, and therefore the rice transplanter 1000 does not become bulky when loaded onto a truck or the like.

Furthermore, according to this embodiment, the operation transmission unit 32' that transmits the operation of the slow-speed forward lever 36 to the speed-change rod 34 is provided with a spring 76 as an example of a transmission prevention means that prevents the operation of the slow-speed forward lever 36 from being transmitted to the speed-change rod 34 when the slow-speed forward lever 36 is pulled at a predetermined operating speed or higher. This prevents the traveling vehicle body 2' from suddenly starting unintentionally when an operator accidentally touches the slow-speed forward lever 36, thereby ensuring even greater safety. Note that in this embodiment, the predetermined operating speed is configured to cause the vehicle body 2 to move forward at a slow speed when the time it takes for the slow-speed forward lever 36 to change from the state before it is pulled to the state where it is completely pulled is 2 seconds or more, but the threshold value of the pulling operation speed for whether or not to move forward at a slow speed can be adjusted by changing the length and hardness of the spring 76.

In addition, according to this embodiment, in the empty box rack 72 provided above the spare seedling frame 74, the pair of front and rear left and right extensions 72d1, which are parts of the main frame body 72d that surround the front and rear of the seedling box, are configured to be lower in height than the pair of left and right front and rear extensions 72d2 and the sub-frame body 72e, which are parts of the frame body that surround the left and right of the seedling box, as shown in FIG. 15. Therefore, when an operator takes an empty seedling box in or out from the front or back of the main frame body 72d and the sub-frame body 72e, the seedling box is less likely to come into contact with the parts of the main frame body 72d and the sub-frame body 72e that surround the front and rear of the seedling box. Therefore, seedling boxes can be easily taken in and out of the empty box rack 72.

Figure 23 is a control block diagram of a rice transplanter 2000 according to yet another preferred embodiment of the present invention, and Figure 24 is a schematic left side view of the vicinity of the variable speed rod 34 according to the embodiment shown in Figure 23.

The rice transplanter 2000 according to this embodiment is configured similarly to the rice transplanter 1000 according to the embodiment shown in Figures 16 to 22, except for the points described below. In the following, the parts configured similarly to the rice transplanter 1000 according to the embodiment are denoted by the same reference numerals and will not be described.

In this embodiment, the rice transplanter 2000 is equipped with a main speed change lever sensor 35a that detects the forward/rearward operating position of the main speed change lever 35, a slow forward lever sensor 36a that detects the pulling operation of the slow forward lever sensor 36, and a travel stop lever sensor 79a that detects the pushing down operation of the travel stop lever 79.

Based on the detection signals output from these sensors 35a, 36a, and 79a, the control unit 87' is configured to drive the HST servo motor 150 shown in FIG. 24 to rotate the gear 101 in either direction, thereby moving the speed change rod 34, the front part of which is attached to the gear 101, back and forth, and moving the traveling vehicle body 2'' forward, backward, slowing down or accelerating, or stopping. That is, in this embodiment, the HST servo motor 150 and the gear 101 are other examples of the "operation transmission unit" of the present invention.

For example, when the main shift lever 35 is operated from the neutral region to the forward region, the control unit 87' drives the HST servo motor 150 to rotate the gear 101 counterclockwise when viewed from the left side, and moves the shift rod 34 rearward, thereby moving the vehicle body 2'' forward.

Similarly, when the main shift lever 35 is in the neutral region and the slow forward lever sensor 36 is pulled (in other words, squeezed like a typical bicycle brake), the control unit 87' drives the HST servo motor 150 to rotate the gear 101 slightly counterclockwise when viewed from the left side.

As a result, the speed change rod 34 is moved slightly rearward, changing the inclination angle of the movable swash plate 25d, and the output shaft 25g of the HST 25 is rotated at a speed sufficient to move the vehicle body 2'' forward at a slow speed.

The rice transplanter 2000 according to this embodiment is equipped with a trunnion axis sensor 100 (see FIG. 23) composed of a potentiometer that detects the rotation angle of the trunnion axis 25a.

The control unit 87' is configured to drive the HST servo motor 150 based on the detection signal of the trunnion axis sensor 100 until the rotation angle of the trunnion axis 25a reaches the target angle (= until the tilt angle of the movable swash plate 25d reaches the target angle).

In addition, when the slow-speed forward movement lever 36 is pulled and the slow-speed forward movement lever sensor 36a detects the detection signal, the brake device is activated and the running wheels 8 and 9 are braked.

At the same time, the depression of the travel stop lever 79 is detected by the travel stop lever sensor 79a, and the control unit 87' drives the HST servo motor 150 based on the output signal of the travel stop lever sensor 79a, causing the gear 101 to rotate clockwise when viewed from the left side.

As a result, the speed change rod 34 is moved forward to a position corresponding to the neutral region of the main speed change lever 35, changing the inclination angle of the movable swash plate 25d and stopping the rotation of the output shaft 25g of the HST 25.

On the other hand, FIG. 25 is a flowchart showing the control performed by the control unit 87' to maintain the position of the aircraft 2000.

In this embodiment, if the operator forgets to apply the brakes using the brake pedal 81 or travel stop lever 79 when the machine 2000 is stopped on a slope, the control unit 87' can drive the HST servo motor 150 as follows to maintain the position of the machine 2000. Hereinafter, the control by the control unit 87' to maintain the position of the machine 2000 is referred to as machine position maintenance control.

When the main shift lever 35 is operated to the neutral region and the vehicle 2000 is stopped, the control unit 87' first determines whether the pitch direction tilt angle A1 of the vehicle body 2'' exceeds the maximum maintaining angle Ap, which is the maximum and predetermined angle at which the position of the vehicle body 2000 can be maintained, based on the detection signal of the IMU (inertial measurement unit) 99, which detects the tilt angle of the vehicle body 2'' (step s1).

If the result of the determination is that the pitch direction tilt angle of the vehicle body 2'' is equal to or less than the maximum maintained angle Ap, the control unit 87' ends the vehicle position maintenance control.

In contrast, if the pitch direction tilt angle of the vehicle body 2'' exceeds the maximum maintained angle Ap, the control unit 87' determines whether the rear wheel 9 is rotating (step s2).

Specifically, when a detection signal is received from the rear wheel rotation sensor 29 that detects the rotation of the rear wheel 9, the control unit 87' determines that the rear wheel 9 is rotating.

If the determination result is that the rear wheel 9 is not rotating, the control unit 87' ends the aircraft position maintenance control.

On the other hand, if the determination result indicates that the rear wheel 9 is rotating, the control unit 87' starts driving the HST servo motor 150 and starts moving the speed change rod 34 (step s3).

When the rear wheel 9 is rotating clockwise in a left side view, the shift rod 34 is moved in a direction that moves the vehicle body 2'' forward (rearward), and when the rear wheel 9 is rotating counterclockwise in a left side view, the shift rod 34 is moved in a direction that moves the vehicle body 2'' backward (frontward).

Next, the control unit 87' determines whether the rotation of the rear wheel 9 has stopped based on the presence or absence of a signal output from the rear wheel rotation sensor 29 (step s4).

If the result of the determination is that the rear wheel 9 has not stopped rotating, the determination is repeated until the rear wheel 9 stops rotating.

In contrast, if the determination result indicates that the rotation of the rear wheel 9 has stopped, the control unit 87' continues to drive the HST servo motor 150 to maintain the rotation angle of the trunnion shaft 25a based on the detection signal of the trunnion shaft sensor 100 at that time (step s5).

Therefore, even if an operator stops the machine 2000 on a slope and forgets to apply the brakes, the machine 2000 can be prevented from sliding down the slope.

The control unit 87' then continues to drive the HST servo motor 150 until some operation is performed, such as operating the main shift lever 35 (step s6).

Figure 26 is a schematic plan view of the rice transplanter 2000 according to the embodiment shown in Figure 23, and Figure 27 is a schematic side view of the first to third spare seedling frames 74a to 74c shown in Figure 26.

As shown in FIG. 26, in this embodiment, the first through fourth spare seedling frames 74a through 74d are provided at the front of the machine body 2000.

Of the first to third spare seedling frames 74a to 74c lined up in the front-to-rear direction, the first spare seedling frame 74a located at the front is connected to the second spare seedling frame 74b by a link mechanism 74f. By rotating the link mechanism 74f, the first spare seedling frame 74a can be switched between a state in which it is located in front of the second spare seedling frame 74b and a state in which it is located above the second spare seedling frame 74b.

On the other hand, the third spare seedling frame 74c, which is located behind the second spare seedling frame 74b, is configured to be rotatable around a pivot point 74g provided at the rear end of the second spare seedling frame 74b, and can be switched between a position extending backward and a position extending upward.

Therefore, even if the machine 2000 is equipped with three spare seedling frames 74a to 74c lined up in the front-to-rear direction, by switching the third spare seedling frame 74c to a position that extends upward, the third spare seedling frame 74c does not get in the way when an operator gets on and off the machine from the right side of the machine 2000.

Furthermore, because the first and third spare seedling frames 74a, 74c can be moved in this way, when the first through third spare seedling frames 74a-74c are arranged in a straight line from front to back, the height of the machine can be reduced and the seedling boxes can be slid in the front to back direction.

As shown in FIG. 26, rails 74e are provided on the inside of the three spare seedling frames 74a to 74c arranged in the front-rear direction, in the width direction of the machine body. The fourth spare seedling frame 74d is configured to be slidable in the front-rear direction along the rails 74e.

Therefore, for example, by stacking empty seedling boxes in the fourth spare seedling frame 74d, a large number of empty seedling boxes can be easily sent out to the front of the machine and collected at once. The rails 74e are configured to be extendable, so that as the fourth spare seedling frame 74d is slid rearward, the rails 74e also become shorter, so that the rails 74e do not get in the way.

The present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included within the scope of the present invention.

For example, in each of the embodiments shown in Figures 1 to 27, the traveling vehicle body is equipped with an engine 7 as a power source for the vehicle body, but an electric motor may be used as a power source instead of or in addition to the engine.

In this case, by inputting the power output from the electric motor to the HST to change the speed, the aircraft can be moved forward at slow speed using the slow forward lever, just like in each of the other embodiments.

Furthermore, in each embodiment shown in Figures 1 to 27, the power output from the HST 25 is configured to be separated into driving power and working power within the transmission case 30, but providing the transmission case 30 is not necessarily required.

Therefore, for example, the HST may be configured to output separate power for travel and power for work.

In addition, in each embodiment shown in Figures 1 to 27, the handle portion 17 is configured as a fixed type that does not rotate, but the handle portion may be configured to rotate downward toward the front.

In this case, the slow forward movement lever is configured to be positioned below the upper end of the handle and behind the front end of the handle before and after the rotation of the handle, thereby ensuring the safety of the operator.

In addition, in each embodiment shown in Figures 16 to 27, the main shift lever 35 is configured not to move from the neutral region when the slow-speed forward lever 36 is pulled, but the main shift lever may be configured to automatically move from the neutral region to the forward region in conjunction with the pulling of the slow-speed forward lever. In this case, it is desirable for the main shift lever to automatically return to the neutral region in conjunction with the rotation of the stopper caused by the pushing down of the travel stop lever.

In the embodiment shown in Figures 23 and 27, step s1 shown in Figure 25 is configured to determine whether the pitch direction tilt angle A1 of the vehicle body 2'' exceeds the maximum maintained angle Ap, but it is not necessarily required to compare the pitch direction tilt angle A1 with the maximum maintained angle Ap. It may be configured to determine whether the tilt angle A1 exceeds an arbitrary threshold value, and if it does, proceed to step s2.

In addition, in the embodiment shown in FIG. 23 and FIG. 27, as shown as step s1 in FIG. 25, the control unit 87' is configured to determine whether the tilt angle A1 in the pitch direction of the vehicle body 2'' exceeds the maximum maintained angle Ap only when the result of determining whether the tilt angle A1 exceeds the maximum maintained angle Ap, but it is not necessarily necessary to determine whether the tilt angle A1 in the pitch direction of the vehicle body 2'' exceeds the maximum maintained angle Ap.

In other words, when the main shift lever is operated to the neutral region, the system may be configured to determine whether the rear wheels are rotating, and if the rear wheels are rotating, to start driving the HST servo motor (step s3).

1 Rice transplanter 2 Traveling vehicle body 3 Main frame 4 Belt-type power transmission mechanism 5 Lifting link device 6 Rear frame 7 Engine 8 Front wheel 9 Rear wheel 10 Link base frame 11 Upper and lower link arm 12 Lifting hydraulic cylinder 13 Front wheel final case 14 Rear wheel transmission shaft 15 Power transmission mechanism 16 Finger lever sensor 17 Handle portion 17a Front end portion of handle portion 17b Upper end portion of handle portion 18 Center mascot 19 Planting on/off switch 20 Sub-transmission mechanism 21 Front wheel rotation sensor 24 Sub-transmission lever 25 HST
25a Trunnion shaft 25b Input shaft 25c Trunnion arm 25d Movable swash plate 25e Hydraulic pump 25f Hydraulic motor 25g Output shaft 25h Hydraulic circuit 26 Fertilizer applicator 27 Planting clutch motor 28 Steering mechanism 29 Rear wheel rotation sensor 30 Transmission case 31 Front wheel axle 32 Operation transmission section 33 Main speed change rod 34 Speed change rod 35 Main speed change lever 36 Slow forward lever 37 Cable 38 Main speed change arm 39 Swing fulcrum 40 Cover inner frame 41 Positioning mechanism 42 Operation arm 43 Switching arm 44 Moving pin 45 Switching arm pivot shaft 46 Cam 46a Cam pivot shaft 47 Front cover 48 Cockpit 49 Control section
50 Spring 51 Rear wheel gear case 52 Mounting hole 53 Mounting hole 54 Insertion hole 55 Insertion hole 56 Long hole 57 Mounting hole 58 Mounting hole 59 First cam pin 60 Floor step 61 Monitor 62 Slow forward drive pin 63 Seedling planting section 64 Planting device 65 Seedling placement table 66 Stay 67 Drive shaft 68 Coil spring 69 Planting tool 70 Inner wire 71 Outer wire 72 Empty box rack 73 First storage section 74 Spare seedling frame 75 Second storage section 76 Spring 77 Lever panel 78 Opening 79 Travel stop lever 80 Second cam pin 81 Brake pedal 82 Rear wheel axle 83 Steering shaft 84 Interlocking rod 85 Upper link arm 86 Lower link arm 87 Control section 88 Electronic hydraulic valve 89 Brake stay 90 Brake shaft 91 Memory section 92 Processing section 93 Neutral return plate 94 Stopper 95 Hub 96 Engine rotation sensor 97 Throttle motor 98 Lock release lever 99 IMU
100 Trunnion axis sensor 101 Gear 150 HST servo motor 1000 Rice transplanter 2000 Rice transplanter

Claims (3)

A traveling vehicle body that travels in a field;
A rice transplanter equipped with a seedling planting unit attached to the rear of the traveling body,
The traveling vehicle body includes a handle portion disposed at a front end portion of the vehicle body, a hydrostatic continuously variable transmission that changes the speed of rotational power supplied from a power source of the vehicle body to output rotational power for traveling, a speed change rod that adjusts the output of the hydrostatic continuously variable transmission, a slow speed forward lever that moves the traveling vehicle body forward at a slow speed, and an operation transmission portion that transmits the operation of the slow speed forward lever to the speed change rod,
The handle portion is formed in a generally inverted U-shape when viewed from the front, and includes a horizontal extension portion extending generally horizontally in the left-right direction, and a pair of left and right curved portions curvedly extending downward from both left and right ends of the horizontal extension portion,
When the slow forward lever is operated while the traveling vehicle body is stopped, the operation transmission unit moves the speed change rod to change the inclination angle of a swash plate that changes the amount of oil discharged from the hydraulic pump of the hydrostatic continuously variable transmission, and a rotational power of a rotational speed at which the traveling vehicle body travels at a slow speed is output from the hydrostatic continuously variable transmission.
The slow forward movement lever is fixed to the lower surface of the horizontal extension portion, and is disposed at a position lower than an upper end of the handle portion and rearward of a front end of the handle portion ,
The rice transplanter is characterized in that the operation transmission unit is equipped with a transmission prevention means that prevents the operation of the slow-speed forward lever from being transmitted to the speed change rod when the slow-speed forward lever is operated at a predetermined operating speed or faster . The traveling vehicle body includes a brake device for braking the traveling wheels;
A brake pedal for actuating the brake device;
a travel stop lever connected to the brake pedal,
The travel stop lever is disposed at the front of the travel vehicle body,
The rice transplanter according to claim 1, characterized in that when the slow-speed forward lever is operated and the travel stop lever is operated, the traveling wheels are braked by the brake device, and the speed change rod is moved in priority to the slow-speed forward operation by the slow-speed forward lever, so that the output of rotational power from the hydrostatic continuously variable transmission is stopped. A spare seedling frame on which seedlings to be replenished to the seedling planting section are placed;
An empty box rack is provided above the spare seedling frame and capable of storing empty seedling boxes in a substantially upright position;
The empty box rack has a frame body that surrounds the front, back, left and right sides of the seedling boxes stored therein,
The frame body includes a pair of front and rear left and right extending portions extending in the left and right direction, and a pair of left and right front and rear extending portions extending in the front and rear direction so as to connect the pair of front and rear left and right extending portions,
The rice transplanter according to claim 1 or 2 , characterized in that the left and right extension portions are configured to be positioned lower than the front and rear extension portions.