Work vehicles

Abstract

In a riding rice transplanter, slow forward movement for crossing ridges and operation of the main transmission mechanism Safety is ensured by regulating relationships with others. [Solution] A working vehicle is provided with a driver's seat, a steering handle, and a main speed change operating unit on a traveling vehicle, and is equipped with a slow speed forward operating unit that can be operated to move the vehicle forward at a slow speed when operated by a worker, and the slow speed forward operating unit can be operated only when the main speed change operating unit is in a neutral position, and when the slow speed forward operating unit is operated, the main speed change operating unit cannot be operated, and when the slow speed forward operating unit is not operated, the vehicle stops without moving forward at a slow speed, and the main speed change operating unit can be operated.

Description

[Technical Field]

[0001] The present invention relates to a work vehicle such as a riding rice transplanter for transplanting seedlings into rice fields. [Background technology]

[0002] Conventionally, in riding rice transplanters in which a driver's seat, steering handle, and main speed change lever are provided on the traveling vehicle and an operator rides to transplant seedlings, examples are known that employ the following structure to enable smooth levee crossing: That is, a riding rice transplanter is known that is equipped with an manual operating tool that can be moved between a storage position stored in the front of the machine body and a working position that moves forward from the storage position and can be operated from the ground, the manual operating tool having an arm attached to the machine body, the arm being divided midway in the longitudinal direction, and having a connecting part that connects the ends of the divided arm parts (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-99241 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such conventional technology, the operation of the manual operating device and the operation of the main transmission mechanism are independent of each other, so there is a possibility that the main transmission mechanism may be operated by mistake when trying to move the vehicle forward slowly using the manual operating device to cross a bank.

[0005] In consideration of such conventional problems, the present invention aims to provide a safe work vehicle by restricting the relationship between the slow forward movement and the operation of the main transmission mechanism.

[0006] Another object of the present invention is to provide a work vehicle that can be manually operated to move forward at a slow speed to cross over a bank more safely. [Means for solving the problem]

[0007] The first aspect of the present invention is A working vehicle is provided with a driver's seat, a steering handle, and a main speed change operation unit on a traveling vehicle, and an operator rides on the vehicle to perform work. The working vehicle is also provided with a slow-speed forward operation unit that can be operated to move the vehicle forward at a slow speed, and when the slow-speed forward operation unit is not operated, the vehicle stops without moving forward at a slow speed, and the main speed change operation unit can be operated. The main speed change operation unit does not return to a neutral position even when the operator does not exert an operating force to operate the vehicle forward or reverse, and the slow-speed forward operation unit returns to an inoperable state when the operator no longer exerts an operating force to operate the vehicle forward at a slow speed. and a positioning mechanism that is rotated by the main speed change operating unit, the positioning mechanism having a main speed change main plate that is rotated by the main speed change operating unit, and a main speed change sub-plate that is connected to the main speed change main plate and rotates, the main speed change main plate being provided with an arc-shaped groove, and a notch being provided in a direction crossing the groove at a central position in the length direction of the groove, which is a position corresponding to the neutral position of the main speed change operating unit, and a slow speed forward arm that moves in response to operation of the slow speed forward operating unit is provided. a slow-speed forward pin is erected at one end of the slow-speed forward arm, a main speed change rod is provided which is driven by the main speed change sub-plate and drives a main speed change body of the HST, the main speed change sub-plate is capable of rotating independently by a predetermined amount with respect to the main speed change main plate, and a plate swing arm is provided which is connected to the slow-speed forward pin of the slow-speed forward arm and is engaged with the main speed change sub-plate, and which rotates the main speed change sub-plate in a predetermined direction as the slow-speed forward pin moves into the notch, By operating the slow forward operation unit with the main speed change operating unit in the neutral position, the slow forward operation pin of the slow forward operation arm is moved to the notch, whereby the plate swing arm rotates the main speed change sub-plate in a predetermined direction, whereby the main speed change rod is driven and the slow forward operation is realized, and the main speed change sub-plate is provided with a notch window through which one end of the main rotation shaft of the main speed change main plate passes with a predetermined amount of play, a main plate side connecting portion is provided on the main transmission main plate at a position spaced a predetermined distance from the main rotation shaft, and a sub-plate side connecting portion is provided on the main transmission sub-plate which is rotatably connected to the main plate side connecting portion of the main transmission main plate, the main transmission main plate and the main transmission sub-plate are connected by a sub-plate tension spring, and a slow forward drive pin provided at one end of the plate swing arm passes through the notched window of the main transmission sub-plate, When the main transmission main plate rotates, the main transmission sub-plate moves and rotates via the main plate side connecting portion and the sub-plate side connecting portion, and even when the main transmission main plate does not rotate, the main transmission sub-plate can be rotated by the slow forward drive pin of the plate swing arm. This is a work vehicle characterized by the above.

[0008] (delete)

[0009] (delete) [Effects of the Invention]

[0010] No. 1 of According to the present invention, a safe work vehicle can be provided by restricting the relationship between the slow forward speed operation and the operation of the main transmission mechanism. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view of a work vehicle according to an embodiment of the present invention; [Figure 2] Partial front view of the work vehicle [Figure 3] A partial side view of Case 1 of the same work vehicle [Figure 4] FIG. 1 is a partially exploded perspective view of the case 1 of the work vehicle. [Figure 5] Partial side view of Case 2 of the same work vehicle [Figure 6] Enlarged view of Figure 5 [Figure 7] FIG. 5 excluding the plate swing arm 42 [Figure 8]Partial side view of Case 3 of the same work vehicle [Figure 9] Partial side view of Case 4 of the same work vehicle [Figure 10] Partial side view of the same work vehicle in Case 4 with high resistance [Figure 11] Partial side view of the work vehicle [Figure 12] Another invention of a field travel diagram [Figure 13] A schematic cross-sectional view and a flowchart of the delivery of a fertilizer application device according to another invention. [Figure 14] (a), (b), (c), and (d) are examples showing the installation positions of antennas of other inventions. [Figure 15] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. [Figure 16] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. [Figure 17] (a), (b), (c), and (d) are examples showing the installation positions of antennas of other inventions. [Figure 18] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. [Figure 19] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. [Figure 20] (a) and (b) Examples showing the installation position of an antenna of a separate invention [Figure 21] (a), (b), (c), and (d) are examples showing the installation positions of antennas of other inventions. [Figure 22] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. [Figure 23] (a), (b), and (c) are examples showing the installation position of an antenna of a separate invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] 1 is a side view of a riding rice transplanter 1 as an example of a work vehicle according to an embodiment of the present invention. In this specification, the left and right sides of the rice transplanter as viewed in the forward direction are referred to as the left and right sides, respectively, and the forward direction is referred to as the front side and the backward direction is referred to as the rear side.

[0014] Here, reference numeral 2 denotes a lifting link device for vertically moving a seedling planting device 3 mounted on the rear of the vehicle body 1' so that it can move up and down. Reference numeral 4 denotes a fertilizer applicator mounted on the upper rear part of the vehicle body 1'. The vehicle body 1' is a four-wheel drive vehicle having a pair of front wheels 6, 6 and a pair of rear wheels 7, 7, which are drive wheels.

[0015] As shown in FIG. 1, a transmission case 11 and an engine 12 are arranged on main frames 10a and 10b, a hydraulic pump is assembled integrally with the rear side of the transmission case 11, and a steering post 14 is erected above the front of the transmission case 11.

[0016] A steering handle 16 is provided at the upper end of the steering post 14. A step floor 19 serving as a passenger floor is attached to the lower part of the vehicle body 1', and a driver's seat 20 is installed above the engine 12. A main speed change lever 17 (hereinafter also referred to as the HST lever 17 as an example) is provided on the left side of the steering handle 16, and an auxiliary speed change lever 26 is provided on the right side.

[0017] An operation panel (not shown) is provided on the steering post 14 in front of the driver's seat 20.

[0018] A clutch lever is provided on the right side of the driver's seat 20. The front wheels 6, 6 are journaled on front wheel support cases 22, 22 that are mounted on the sides of the transmission case 11 so that their orientation can be changed. The rear wheels 7, 7 are journaled via rear wheel supports 30 on rear wheel transmission cases 24, 24 attached to both the left and right ends of the left and right frames.

[0019] As shown in FIG. 1, which shows a portion of the power transmission mechanism to the rear wheels 7, the rotational power of the engine 12 is transmitted to the input shaft 32a of the hydraulic continuously variable transmission (HST) 31 via a pulley 27, a belt 28, and a pulley 29 in that order, and is then transmitted from the output shaft 32b of the HST 31 into the transmission case 11.

[0020] The rear end of the rear output shaft 11a of the transmission case 11 protrudes rearward from the transmission case 11, and left and right rear wheel transmission shafts 35, 35 that transmit power to the rear wheel transmission cases 24, 24 are connected to this protruding end. The left and right rear wheel transmission shafts 35, 35 are configured to drive and rotate the left and right rear wheels 7, 7, respectively.

[0021] Additionally, an inverted U-shaped front handle (ridge-crossing handle) 5 is pivotally mounted on the front of the vehicle body 1'. This front handle 5 can be gripped by an operator and pushed down to tilt the vehicle forward, thereby preventing the front end of the vehicle body 1' from lifting up too much when the vehicle body 1' crosses a step such as a ridge, or conversely, helping the front end to point upward at the beginning of crossing the ridge.

[0022] As shown in FIG. 1, the lower end of the front handle 5 is pivotally supported on the vehicle body 1' by a pivot shaft 56.

[0023] The lower end of the HST lever 17 is connected to a positioning mechanism 41, which will be described later. Through this positioning mechanism 41, the HST lever 17 can operate a main transmission rod 510 that drives the transmission section of the HST 31, and forward and backward movement can be achieved by rotating the HST lever 17 back and forth.

[0024] A center mascot 89 is attached to the vehicle body 1' on the vehicle body side of the front handle 5, and a lamp 89a is provided.

[0025] In this way, when the vehicle body 1' crosses the ridge in the field, the vehicle body 1' rises to the front, so the operator gets around to the front of the vehicle body 1' and uses the front handle 5. When trying to stop the vehicle body 1' during the use of the front handle 5, the engine operation / stop switch 90 is arranged on the upper surface of the steering post 14, and the operator can operate the engine operation / stop switch 90 from the front of the vehicle body 1', and it is possible to stop the vehicle body 1'.

[0026] Figure 2 is a perspective view of the front part of the vehicle body 1'. A micro-speed forward lever 8 is attached to the above-described inverted U-shaped loop-shaped front handle 5 provided on the front side of the vehicle body 1' for crossing the ridge. Here, the micro-speed forward lever 8 is arranged inside the loop of the loop-shaped front handle 5, and is attached at a position that does not protrude forward from the front surface 5a1 of the handle part 5a of the front handle 5 and does not protrude backward from the rear surface 5a2 either.

[0027] By making it such a size and arrangement, when a person is sandwiched between the vehicle body 1' and an obstacle behind when operating the micro-speed forward lever 8 with the front handle 5 raised, if the micro-speed forward lever 8 protrudes from the front and rear surfaces of the handle part 5a of the front handle 5, there is a risk that the micro-speed forward lever 8 will mechanically lock and the forward movement of the vehicle body 1' will not stop, but the problem can be solved by the above-described configuration.

[0028] Also, in a rice transplanter that can load a light truck, there is a constraint on the overall length and it is better to be as short as possible, but by adopting the above configuration, there is an advantage that the overall length of the machine body does not become too long.

[0029] Hereinafter, the cases of normally moving the vehicle body 1' forward and backward using the HST lever 17, moving the vehicle body 1' forward at a micro-speed using the micro-speed forward lever 8, and the case of stopping will be described.

[0030] <Case 1 where the HST lever 17 is in the neutral position and the micro-speed forward lever 8 is not grasped> In this state, the vehicle body 1' naturally does not move forward or backward. Figure 3 shows the positioning mechanism 41 and other components in this state. Here, the positioning mechanism 41 is made up of a main transmission main plate 41a, a main transmission sub-plate 41b, and other components. Figure 4(A) is an exploded perspective view of the main transmission main plate 41a and the main transmission sub-plate 41b.

[0031] Main transmission main plate 41a is rotatable around a main rotation shaft 41a1 fixed to vehicle body 1' as its central axis. As shown in Figures 4(A) and 4(C), this main transmission main plate 41a is provided with an arc-shaped groove 41c1, and a notch 41c2 is provided in a direction intersecting groove 41c1 at the center position in the length direction of groove 41c1, which corresponds to the neutral position of HST lever 17. Figure 4(C) is a front view of groove 41c1.

[0032] On the other hand, the upper end of a cable 8a that is pulled by gripping the slow forward movement lever 8 is connected to a first cam pin 47a fixed to a cam 46. This cam 46 is rotatable around a cam rotation shaft 46a fixed to the vehicle body 1'.

[0033] Meanwhile, an advancing arm pivot shaft 45 of a rod-shaped slow-speed advancing arm 43 is fixed to the vehicle body 1' near the cam 46. Furthermore, an advancing arm pin 43a is erected at the right end of the slow-speed advancing arm 43 in the drawing, and this advancing arm pin 43a abuts against the periphery of the cam 46. Therefore, the slow-speed advancing lever 8, cable 8a, cam 46 and advancing arm pin 43a are interlocked.

[0034] A slow-speed forward movement pin 44 is fixed to the left end of the slow-speed forward movement arm 43 in the drawing, with one end inserted into the groove 41c1 and able to move into the notch 41c2. Therefore, as shown in Figure 4(C), this slow-speed forward movement pin 44 can be placed in four different positions as the main transmission main plate 41a rotates.

[0035] That is, position 44a is when the HST lever 17 is in the neutral position and the slow forward lever 8 is not grasped (corresponding to case 1 in this case), 44b is when the HST lever 17 is in the forward position and the slow forward lever 8 is not grasped (corresponding to case 3 described later), 44c is when the HST lever 17 is in the reverse position and the slow forward lever 8 is not grasped (corresponding to case 4 described later), and 44d is when the HST lever 17 is in the neutral position and the slow forward lever 8 is grasped and the slow forward pin 44 is positioned in the notch 41c2 (corresponding to case 2 described later).

[0036] On the other hand, the main transmission sub-plate 41b is connected to the main transmission main plate 41a, as shown in Figure 4(B). That is, the main transmission sub-plate 41b has a cutout window 41b1 through which the tip of the main rotation shaft 41a1 of the main transmission main plate 41a passes with a predetermined amount of play space S. Furthermore, the main transmission main plate 41a is provided with a main plate-side connecting portion 41a2 at a position a predetermined distance away from the main rotation shaft 41a1, while the main transmission sub-plate 41b is provided with a sub-plate-side connecting portion 41b2 that is rotatably connected to the main plate-side connecting portion 41a2 of the main transmission main plate 41a. As an example, the main plate-side connecting portion 41a2 is a cylindrical member, and the sub-plate-side connecting portion 41b2 is a pin that is rotatably inserted into the cylindrical member, but this may be reversed, or other connecting methods may be used. In any case, even when the main transmission main plate 41a does not move or rotate, the main transmission sub-plate 41b can rotate independently by a predetermined amount.

[0037] The main transmission main plate 41a and the main transmission sub-plate 41b are connected by a sub-plate tension spring 50, and the main transmission sub-plate 41b is always biased to rotate clockwise.

[0038] 3 denotes a bent plate swing arm 42, which is arranged in front of the slow-speed advance arm 43 (as viewed from the plane of the drawing), and is connected to the slow-speed advance arm 43 by the slow-speed advance pin 44 passing through approximately the center of the plate swing arm 42. A slow-speed advance drive pin 48 is erected at the lower end of the plate swing arm 42, and an elongated hole 42a is drilled in the upper right end.

[0039] The slow forward drive pin 48 passes through a notched window 41b1 in the main transmission sub-plate 41b and is able to press the inner edge of the notched window 41b1. A first cam pin 47a erected on a cam 46 is fitted into the elongated hole 42a.

[0040] In this case 1, the main speed change lever 17 is in the neutral position, so the main speed change main plate 41a is in the neutral position. On the other hand, the slow forward lever 8 is not gripped, so the cable 8a is not pulled and the cam 46 is in an upward position. As a result, the forward arm pin 43a is not pushed downward, and the right end of the slow forward arm 43 is biased counterclockwise by a coil spring (built into the forward arm pivot shaft 45) and is in an upward position. Even when the cam 46 is rotated upward, a locking projection 46b protruding from the lower end of the cam 46 rotates upward to prevent the forward arm pin 43a from remaining lowered, forcing the forward arm pin 43a to reliably move upward. Although not visible in FIG. 3, the forward arm pin 43a fits into a recessed portion 46c of the cam 46 (see FIG. 6).

[0041] Therefore, the slow-speed forward movement pin 44 at the left end of the slow-speed forward movement arm 43 is in a lowered state (corresponding to 44a in FIG. 4(C)).

[0042] Since the low-speed forward pin 44 is in the lowered state, the central position of the connected plate swing arm 42 is also in the lowered state. At the same time, since the cam 46 is rotating upward, the right end of the plate swing arm 42 inserted into the long hole 42a is raised. As a result, the low-speed forward drive pin 48 at the lower end of the plate swing arm 42 will be positioned at a position that does not press the notch window 41b1 of the main transmission sub-plate 41b, as shown in FIG. 3.

[0043] As a result, the main transmission sub-plate 41b is positioned at the position shown in the figure with the sub-plate side connecting portion 41b2 as the axis by the sub-plate tension spring 50. That is, the main rotation shaft 41a1 is positioned at the position where it abuts against the normal side edge 41b11.

[0044] When the main transmission sub-plate 41b is in such a state, the main transmission rod 510 attached to the main transmission rod mounting hole 51 provided at the lower end is pre-designed to set the HST31 to the neutral position.

[0045] In the above manner, the vehicle body 1' is in a stopped state.

[0046] <Case 2 where the low-speed forward lever is grasped with the HST lever in the neutral position> Next, a description will be given of Case 2 in which the low-speed forward lever 8 is grasped while the HST lever 17 is positioned at the neutral position, starting from the state of Case 1. FIGS. 5, FIG. 6 (a partially enlarged view of FIG. 5), and FIG. 7 (a view with the plate swing arm 42 removed from FIG. 5) show the state of that Case 2. Note that 49 is a spring that biases the main transmission main plate 41a. It is an assist spring for preventing the automatic return of the main transmission lever 17 (a phenomenon in which the main transmission lever 17 moves automatically in the neutral direction due to the load during field operation).

[0047] In this case 2, because the main speed change lever 17 is in the neutral position, the main speed change main plate 41a remains in the neutral position. On the other hand, because the slow forward lever 8 is gripped, the cable 8a is pulled and the cam 46 rotates downward. That is, the recessed portion 46c of the cam 46 also rotates, so the forward arm pin 43a is also pushed downward a predetermined amount by the corner of the recessed portion 46c, and eventually it leaves the corner and is held in a fixed position by the circular portion of the cam 46. That is, the right end of the slow forward arm 43 rotates a predetermined amount clockwise against the coil spring. As a result, the slow forward pin 44 at the left end of the slow forward arm 43 rotates a predetermined amount clockwise and moves upward, fitting into the notch 41c2 (corresponding to 44d in Figure 4(C)).

[0048] At the same time, the central portion of the plate swing arm 42 connected to the slow forward movement pin 44 also moves upward. On the other hand, as the cam 46 rotates downward, the right end of the plate swing arm 42 connected to the cam first pin 47a via the elongated hole 42a moves downward.

[0049] As a result, the plate swing arm 42 rotates clockwise as a whole. This causes the slow-speed forward drive pin 48 fixed to the lower end of the plate swing arm 42 to move clockwise, and the movement of the slow-speed forward drive pin 48 pushes the cutout window 41b1 (main-transmission sub-plate 41b) that is in contact with it, causing it to move counterclockwise. In this case, the main-transmission main plate 41a does not move, so the main-transmission sub-plate 41b rotates around the sub-plate-side connecting portion 41b2 (main-plate-side connecting portion 41a2) located below. At that time, the main rotation shaft 41a1 that passes through the cutout window 41b1 does not interfere with the rotation of the main-transmission sub-plate 41b due to the play space S below the cutout window 41b1, so the main-transmission sub-plate 41b can rotate.

[0050] As a result, the main speed-change rod 510 at the lower end of the main speed-change sub-plate 41b rotates clockwise, and the main speed-change rod 510 moves the HST 31 forward at slow speed. Here, the amount of counterclockwise rotation of the main speed-change sub-plate 41b is restricted at that position by the slow-speed side edge 41b12 of the cutout window 41b1 abutting against the main rotation shaft 41a1, so there is no risk of the main speed-change rod 510 moving too far and moving forward significantly, and slow-speed forward movement can be achieved.

[0051] As mentioned above, in this case 2, the slow-speed forward movement lever 8 is grasped and the slow-speed forward movement pin 44 at the left end of the slow-speed forward movement arm 43 rotates clockwise and moves upward, fitting into the notch 41c2 (corresponding to 44d in Figure 4(C)), so while the vehicle is moving forward at slow speed, the main transmission main plate 41a cannot rotate in either the forward or reverse direction, ensuring safety.

[0052] <Case 3: The HST lever was put into forward gear without understanding the slow forward gear lever> Next, as shown in FIG. 8, a normal forward movement will be described in which the HST lever 17 is moved in the forward direction from the state of Case 1 without gripping the slow forward movement lever 8 (corresponding to 44b in FIG. 4).

[0053] In this case, the main transmission main plate 41a rotates counterclockwise around the main rotation shaft 41a1. As a result, the main plate side coupling part 41a2 rotates counterclockwise, and the sub-plate side coupling part 41b2 connected thereto also rotates counterclockwise. As a result, the main transmission rod mounting hole 51 at the lower end of the main transmission sub-plate 41b also rotates counterclockwise, and the main transmission rod 510 attached to the main transmission rod mounting hole 51 moves the HST 31 forward. In Case 3, there are no particular restrictions on the amount of rotation of the main transmission main plate 41a, so it can also be moved forward significantly.

[0054] In the case of Case 3, the slow-speed forward movement pin 44 slides on the right side of the groove 41c1, but since there is no notch 41c2 on that right side, even if the slow-speed forward movement lever 8 is grasped and the cable 8a is pulled while moving forward, the slow-speed forward movement pin 44 cannot move upward, and it is safe.

[0055] <Case 4: The HST lever was put into reverse without understanding the slow-forward lever> Next, as shown in FIG. 9, a normal reverse movement case will be described in which the HST lever 17 is moved in the reverse direction from the state of Case 1 without gripping the slow forward movement lever 8 (corresponding to 44c in FIG. 4).

[0056] In this case, the main transmission main plate 41a rotates clockwise around the main rotation shaft 41a1. As a result, the main plate side coupling part 41a2 rotates clockwise, and the sub-plate side coupling part 41b2 connected thereto also rotates clockwise. As a result, the main transmission rod mounting hole 51 at the lower end of the main transmission sub-plate 41b also rotates clockwise, and the main transmission rod 510 attached to the main transmission rod mounting hole 51 moves the HST 31 in reverse. In Case 4, there are no particular restrictions on the amount of rotation of the main transmission main plate 41a, so it is possible to move the HST 31 in reverse a large distance.

[0057] Furthermore, when reversing in this manner, if a heavy load is applied due to a deep field, for example, the sub-plate side connecting portion 41b2 will rotate clockwise around the main pivot shaft 41a1 as described above, but the main speed-change rod mounting hole 51 will not move immediately, so as a reaction, the upper part of the main speed-change sub-plate 41b will begin to move counterclockwise (the main speed-change sub-plate 41b has play space S in the cutout window 41b1) and will move until the slow-speed side edge 41b12 abuts against the main pivot shaft 41a1 (see Figure 10), and then the main speed-change rod mounting hole 51 will begin to rotate clockwise against the heavy load of the field.

[0058] In other words, in such a heavily loaded field, even if a command is given to move in reverse, the operation of the HST 31 is delayed because of the play space S, making it possible to move in reverse at a higher engine speed than during normal operation.

[0059] In other words, the system is designed so that engine speed increases in proportion to the rotation angle of main transmission main plate 41a, and main transmission sub-plate 41b is held in a fixed position relative to main transmission main plate 41a only by the load of sub-plate tension spring 50, which has a small spring force, and normally rotates in unison with main transmission main plate 41a, but when the field load increases during reverse, the force that tries to return HST 31 to the neutral position increases, and when the force exceeds the load of the small spring, only main transmission sub-plate 41b rotates, and the HST opening is suppressed. At this time, main transmission main plate 41a is rotating at the same rotation angle as normal, so engine speed is the same as normal, but the HST opening is suppressed, so vehicle speed is slower than normal.

[0060] In the case of this case 4, the slow-speed forward movement pin 44 slides on the left side of the groove 41c1, but since there is no notch 41c2 on that left side, the slow-speed forward movement pin 44 cannot move upward even if the slow-speed forward movement lever 8 is grasped and the cable 8a is pulled. Safety is ensured.

[0061] In other words, as explained in Cases 3 and 4, when the main speed change lever 17 is in a position other than the neutral position, the slow forward movement pin 44 cannot move to the notch 41c2 of the main speed change main plate 41a, and as a result, the slow forward movement lever 8 cannot be operated, ensuring safety.

[0062] As explained in the above cases 1, 2, 3, and 4, the present invention has the advantage that complex operations can be performed with a single cable.

[0063] FIG. 11 shows a modified example in which the engine speed increases when the vehicle is driven forward at a slow speed compared to normal.

[0064] That is, when the slow forward speed lever 8 is grasped and the cable 8a is pulled, causing the cam 46 to rotate downward, the second cam pin 47b fixed to the top of the cam 46 rotates clockwise around the cam rotation shaft 46a. This second cam pin 47b is connected to an engine speed control arm 52 that can increase or decrease the rotation speed of the engine 12, so when moving slowly forward, the rotation speed controlled by the auto-accelerator of the engine 12 can be automatically increased.

[0065] This eliminates the need for dangerous actions such as operating the pedal to increase the engine speed when moving forward at slow speed, and the engine speed can be increased simply by operating the slow speed forward lever 8.

[0066] Furthermore, there is no need to install new cables, making the configuration simpler.

[0067] Next, another invention will be described.

[0068] Conventional technology determines turning timing by detecting drive rotation, but by basically specifying turning timing using GNSS and collecting rotation speed as a backup, it is possible to determine turning timing to some extent even if the vehicle is lost.

[0069] In addition to this, the slip rate (actual travel distance / distance converted from driving rotations) is calculated at this timing and used to correct the rotation count when the wheel is lost.

[0070] This also makes it possible to deal with satellite loss. It has the advantage of being able to measure the actual slip ratio and make driving corrections.

[0071] Conventional technology assumes an ideal rectangular field, and is therefore unable to adapt to irregular fields.

[0072] Therefore, the next path (length) is predicted (differential) by taking the difference in distance between the first and second paths. The first and second paths are updated sequentially. This allows the system to adapt to deforming fields (see Figure 12).

[0073] Next, another invention will be described.

[0074] Previously, the direction of the aircraft at the start of automatic turning had a significant impact on the accuracy of so-called Z-turns (in which the planting section automatically rises when the steering wheel is turned to turn).

[0075] When performing turning assistance, deviation from the parallel line stored in memory for straight-line assistance is taken into account (before starting automatic turning, the aircraft's direction is considered to be deviated from a straight line). The timing for starting a Z-turn is changed depending on the deviation from the parallel line. This can improve Z-turn accuracy. In the past, when trying to maintain vehicle speed, straight-line assist devices (even manual devices) required steering inputs to be reduced.

[0076] Therefore, the automatic straight-line driving system controls the amount of steering depending on the frequency of steering control (if the interval between counters is short, the amount of steering is reduced).

[0077] This allows for improved planting performance (straightness) without changing the work speed.

[0078] In the past, in straight-line assist systems (and manual systems as well), the vehicle speed was reduced in situations where frequent steering operations were required.

[0079] Therefore, we have implemented a system that regulates vehicle speed according to the frequency of steering control.The automatic straight-line driving system controls vehicle speed according to the frequency of steering control (if the interval between counter hits is short, the vehicle speed will be reduced).

[0080] This improves planting accuracy (straightness).

[0081] Previously, when automatic steering was performed at a constant speed, straight-line stability was impaired if the steering wheel was turned too much.

[0082] To address this issue, we have developed a gain-priority variable speed control system, which controls the speed (HST lever operation) by prioritizing the amount of steering wheel operation (gain) set by the automatic straight-line driving system.

[0083] This minimizes deviation of the planting area without changing the steering feel.

[0084] Conventionally, when automatic steering is performed with a constant gain, straight-line stability is impaired as the speed increases.

[0085] To address this issue, we have implemented a speed-priority variable gain. The automatic straight-line driving system controls the amount of steering operation (gain) with priority given to the set speed (HST lever operation).

[0086] This minimizes displacement of the planting portion.

[0087] Conventionally, automatic control systems basically need to detect three components (rolling, pitching, and yawing), but taking rolling into account when traveling straight results in large deviations in the planting area (rolling occurs when the height of the tillage pan that touches the ground is different between the left and right wheels. In this case, countersteering to compensate for the deviation from the reference position causes the planting area to deviate too much).

[0088] Therefore, automatic straight-line driving systems perform control by eliminating or suppressing the rolling component of the deviations (rolling, pitching, yawing) from the control target.

[0089] This minimizes displacement of the planting portion.

[0090] Conventionally, automatic driving control is performed based on the center of the steering wheel axis (driving base), but deviations become large in the planting area, which is far from the reference point. Using the planting area as the reference point is greatly affected by the field surface.

[0091] Therefore, the automatic straight-line driving system places a GNSS antenna above the center of the fixed wheelset and controls the vehicle from that point.

[0092] This allows the center of the machine to be used as a reference point, minimizing deviations in planting while also reducing deviations in travel.

[0093] Conventionally, automatic driving control is performed based on the center of the steering wheel axis (driving base), but deviations become large in planting areas that are far from the reference point.

[0094] Therefore, an automatic straight-line system is used to control the planting unit to minimize its travel distance. A GNSS antenna (receiver) is installed above the center of the planting unit.

[0095] This improves planting accuracy.

[0096] The next invention activates the auto differential lock when the vehicle is on an incline, ensuring reliable climbing. In other words, once the differential lock is activated with the front of the vehicle raised, it will not be disengaged until the vehicle has reached the top of the slope.

[0097] This will allow you to climb hills with confidence.

[0098] In addition, the auto differential lock is activated when tilting, and is activated for a fixed rotational speed when the front is raised.

[0099] Previously, when exiting a field, if there were ruts or other obstacles on the slope, the machine would slip, but it was difficult to press the differential lock pedal when the machine was tilted.

[0100] Therefore, the auto differential lock is activated when the vehicle spins while leaning.

[0101] This allows for effective torque transmission while minimizing the use of differential lock.

[0102] Previously, when exiting a field, if there were ruts or other obstacles on the slope, the machine would slip, but it was difficult to press the differential lock pedal when the machine was tilted.

[0103] Therefore, the automatic differential lock is activated when the vehicle is moving straight ahead on an incline.

[0104] This ensures safety.

[0105] Conventionally, as shown in Figure 13, when clogging occurs, it creates a non-fertilized section.

[0106] Therefore, in the control of the motor-driven fertilizer applicator, when the load torque (current value) exceeds a certain value, an alarm is issued by the alarm means. In the case of automatic driving, the operation is stopped, the blockage is cleared, and then automatic driving is resumed.

[0107] This makes it possible to prevent the self-driving rice transplanter from creating areas where no fertilization is required.

[0108] Next, we will explain the invention regarding the antenna layout of a robotic rice transplanter. In particular, we will take the example of a Bluetooth (registered trademark) antenna.

[0109] As shown by the arrow in Figure 14, the Bluetooth antenna for the VRS of the robot rice transplanter is laid out inside the straight-line assist monitor case, so that it does not get in the way of work.

[0110] As shown by the arrow in Figure 15, the Bluetooth antenna for the robot rice transplanter's VRS is located inside the front mask, at the top. This prevents it from interfering with work. The mechanism can be protected by being inside the cover.

[0111] As shown by the arrow in Figure 16, the Bluetooth antenna for the VRS of the robotic rice transplanter is located above the center of the hopper. This minimizes interference with work. It also makes it easier to communicate with terminals, which are often stored behind the seat.

[0112] As shown by the arrow in Figure 17, the Bluetooth antenna for the VRS of the robot rice transplanter is laid out on the straight-line assist monitor stay, so that it does not get in the way of work.

[0113] As shown by the arrow in Figure 18, the Bluetooth antenna of the robotic rice transplanter is placed above the auxiliary seedling frame (support), so that it does not get in the way of work.

[0114] As shown by the arrow in Figure 19, the Bluetooth antenna for the robotic rice transplanter's VRS is located behind the seat. This prevents it from getting in the way of work while riding. Terminals are often stored behind the seat, making it easy to communicate with the terminals.

[0115] As shown by the arrow in Figure 20, the Bluetooth antenna for the robotic rice transplanter's VRS is placed on the panel. It is unlikely to get in the way of work. There is no contact with obstacles. It is easy to be aware of the antenna position, which improves operation and maintenance.

[0116] As shown by the arrow in Figure 21, the Bluetooth antenna for the robot rice transplanter's VRS is placed inside the GNSS antenna case. It is less likely to interfere with work. There is no contact with obstacles. It is physically protected and increases durability. Antenna-related items can be consolidated (consolidation of wiring).

[0117] It is desirable to shift it from the center so that it is outside the receiving angle of the GNSS antenna.

[0118] As shown by the arrow in Figure 22, the Bluetooth antenna for the VRS of the robotic rice transplanter is located behind the GNSS antenna case. This makes it less likely to interfere with work. There is no contact with obstacles. It also makes it easier to communicate with the terminal, which is often stored behind the seat.

[0119] As shown by the arrow in Figure 23, the Bluetooth antenna for the robot rice transplanter's VRS is located at the tip of the center mascot. This prevents it from interfering with work. The wiring can be passed inside the support and protected. [Industrial Applicability]

[0120] The present invention realizes a work vehicle that allows manual operation of slow forward movement to cross levees more safely, and is ideal for riding rice transplanters. [Explanation of symbols]

[0121] 1. Riding rice transplanter 1' Body 5 Front Handle 8 Slow forward lever 8a cable 17 Main transmission lever (HTS lever) 31 HST 41 Positioning mechanism 41a Main transmission main plate 41a1 Main rotation axis 41a2 Main plate side connection part 41b Main transmission sub-plate 41b1 Cutout window 41b11 Normal side edge 41b12 Low speed side edge 41b2 Sub-plate side connection part 41c1 Groove 41c2 notch 42 Plate swing arm 43 Slow forward arm 43a Advance arm pin 44 Slow forward pin 44a, 44b, 44c, 44d each position 45 Forward arm rotation axis 46 Cam 46a Cam rotation shaft 46b Locking protrusion 46c Recessed part 48 Slow forward drive pin 50 Sub-plate tension spring 510 Main transmission rod S Play Space

Claims

[Claim 1] In a work vehicle in which a driver's seat, a steering handle, and a main transmission operation unit are provided on the traveling vehicle and a worker rides on it to perform work, It is equipped with a slow-speed forward operation unit that can be operated to move forward at a slow speed, When the slow-speed forward operation unit is not operated, the vehicle does not move forward at a slow speed but stops, and the main speed change operation unit can be operated. The main speed change operation unit does not return to the neutral position even when the operator does not apply an operating force for forward or reverse operation, The slow-speed forward movement operating unit returns to a non-operated state when the operating force for the slow-speed forward movement by the operator is removed, a positioning mechanism that is rotated by the main speed change operating part, the positioning mechanism includes a main transmission main plate that is rotated by the main transmission operating part, and a main transmission sub-plate that is connected to the main transmission main plate and rotates, an arc-shaped groove is provided in the main transmission main plate, and a notch is provided in a direction intersecting the groove at a central position in the length direction of the groove, which is a position corresponding to the neutral position of the main transmission operating part; a slow-speed advance arm that moves in response to operation of the slow-speed advance operation unit is provided, and a slow-speed advance pin is erected at one end of the slow-speed advance arm; a main transmission rod driven by the main transmission subplate and driving a main transmission body of the HST; the main transmission sub-plate is independently rotatable by a predetermined amount relative to the main transmission main plate, a plate swing arm connected to the slow-speed forward movement pin of the slow-speed forward movement arm and engaged with the main-speed change sub-plate, the slow-speed forward movement pin moving into the notch to rotate the main-speed change sub-plate in a predetermined direction; By operating the slow-speed forward movement operating unit while the main speed change operating unit is in the neutral position, the slow-speed forward movement pin of the slow-speed forward movement arm is moved to the notch, whereby the plate swing arm rotates the main speed change sub-plate in a predetermined direction, whereby the main speed change rod is driven and the slow-speed forward movement is realized; a cutout window is formed in the main transmission sub-plate, through which one end of the main rotation shaft of the main transmission main plate passes with a predetermined amount of play; The main transmission main plate is provided with a main plate side connecting portion at a position spaced a predetermined distance from the main rotation shaft, The main transmission sub-plate is provided with a sub-plate side connecting portion rotatably connected to the main plate side connecting portion of the main transmission main plate, The main transmission main plate and the main transmission sub-plate are connected by a sub-plate tension spring, a slow forward drive pin provided at one end of the plate swing arm passes through the notched window of the main transmission sub-plate; By the rotation of the main transmission main plate, the main transmission sub-plate moves and rotates through the main plate side connecting portion and the sub-plate side connecting portion, Even when the main transmission main plate is not rotating, the main transmission sub-plate can be rotated by the slow forward drive pin of the plate swing arm. A work vehicle characterized by:

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