Work vehicles

Abstract

To make a moving work vehicle traveling in plant cultivation facility perform entry positioning to an adjacent working passage easily and efficiently.SOLUTION: In a working vehicle that travels on each working passage 9 between a large number of cultivation beds 5 and a moving passage 4 leading to each working passage 9 at an end part of the cultivation beds 5, a bearing ring 20b traveling on a pair of right / left rails 13 arranged on each working passage 9 and wheels 35 traveling on the moving passage 4 are provided for a traveling vehicle body 21, and the wheels 35 traveling on the moving passage 4 are provided switchable between a traveling state where the wheels contact the ground by an elevator mechanism 39 and a non-traveling state where the wheels are raised. Working passage entry position detection sensors 45 which detect the rails 13 are provided for a side opposing to the rails 13 of the traveling vehicle body 21, and the sensors stop the working vehicle body 21 when a working passage entry position is detected when traveling on the moving passage 4.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a work vehicle, such as a transport vehicle, that transports storage buckets for storing harvested crops in a plant cultivation facility. [Background technology]

[0002] In a plant cultivation facility, there is a configuration of a traveling device that performs work traveling in a work passage along a crop cultivation row and travel traveling in a travel passage that leads to a work passage along another crop cultivation row (Patent Document 1) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-163928 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, when the control device determines that the work vehicle has left the work aisle, the outside of the left and right running wheels are rotated forward and the inside of the wheels are rotated in the reverse direction, causing the running body to turn on the spot, which has the advantage of reducing the turning radius.

[0005] However, since the traveling vehicle body turns, it is difficult to align the entry position into the next adjacent work passage.

[0006] In view of the above, an object of the present invention is to easily and efficiently align an entry position into an adjacent working passage. [Means for solving the problem]

[0007] The first aspect of the present invention is In a work vehicle that travels on each of the work passages 9 between a large number of cultivation beds 5 and on a moving passage 4 that leads to each of the work passages 9 at the end of the cultivation beds 5, a traveling body 21 is provided with raceways 20b that travel on a pair of left and right rails 13 arranged on each of the work passages 9 and wheels 35 that travel on the moving passage 4, and the wheels 35 that travel on the moving passage 4 are provided so as to be switchable by a lifting mechanism 39 between a running state in which they are in contact with the ground and a raised non-running state, The travelling body 21 is provided with work passage entry position detection sensors 45L, 45R at the left and right front portions thereof, As the traveling body 21 moves along the travel passage 4 by the wheels 35, the preceding work passage entry position detection sensor 45R detects the rail 13L closer to the direction of travel and then the rail 13R farther from the direction of travel, and when it detects the rail 13R farther from the direction of travel, it can detect the entry position of the work passage 9, This work vehicle is characterized in that the distance between the left and right work aisle entry position detection sensors 45L, 45R is greater than the distance between the pair of rails 13, so that the control unit can detect the traveling vehicle body 21 going too far by the trailing work aisle entry position detection sensor 45L detecting the rail 13L closer in the direction of travel after the leading work aisle entry position detection sensor 45R detects the rail 13R farther in the direction of travel. The second aspect of the present invention is The first work vehicle of the present invention is characterized in that, when the control unit detects that the traveling body 21 has gone too far, it drives the wheels 35 to move the traveling body 21 backward and reach the entry position. The third aspect of the present invention is A pair of rails 13 are provided with end portions 13t formed in a substantially U-shape, the end portions 13t being provided on the starting end side of each of the work passages 9, and a detection member 46 is provided in the left and right central portion, This is a work vehicle of the first or second invention, characterized in that a forward detection sensor 47f is provided in the center of the left and right of the traveling body 21, and when the forward detection sensor 47f detects the detectable member 46, the control unit determines that the entrance to the work passage 9 has been reached. The first invention related to the present invention In a work vehicle that travels on each of the work passages 9 between a large number of cultivation beds 5 and a moving passage 4 that leads to each of the work passages 9 at the end of the cultivation beds 5, a running body 21 is provided with a track wheel 20b that runs on a pair of left and right rails 13 arranged on each of the work passages 9 and a moving passage 4. Running The vehicle is provided with wheels 35 and travels along the moving path 4. Running The wheels 35 are provided so as to be switchable between a running state in which they are in contact with the ground and a raised, non-running state by a lifting mechanism 39.

[0008] The second invention related to the present invention is the first invention related to the present invention. In the above, a work passage entry position detection sensor 45 for detecting the rail 13 is provided on the side of the traveling vehicle body 21 facing the rail 13, and when the work passage entry position is detected while the moving vehicle is traveling on the moving passage 4, Running The vehicle body 21 is configured to be stopped.

[0009] The third invention related to the present invention is the first or second invention related to the present invention. In the vehicle, a forward detection sensor 47f and a reverse detection sensor 47r for detecting a detection target member 46 are provided at the front and rear of the traveling vehicle body 21.

[0010] The fourth invention related to the present invention is any one of the first to third inventions related to the present invention. In the vehicle, the front, rear, left and right track wheels 20b that run on the rail 13 and the running wheels 35 for running on the transfer path 4 are positioned to face each other at each of the four corners at a predetermined distance in the front and rear directions, and a battery 41 is disposed within this predetermined distance range. Effect of the Invention

[0011] According to the present invention, the passing of the traveling vehicle body 21 on the passage 4 can be detected reliably. The first invention related to the present invention According to the invention, when the traveling body 21 moves to an adjacent cultivation bed 5, the change in the posture of the traveling body 21 when moving between the cultivation beds is reduced, and the positioning is facilitated. In addition, since the traveling body 21 does not rotate, the space of the moving passage 4 can be made compact.

[0012] According to the second and third inventions related to the present invention, the first invention related to the present invention In addition to the above effects, the work passage entrance position detection sensor 45 can reliably detect the rail 13. The third invention related to the present invention This allows the traveling body 21 to be spaced a predetermined distance from the cultivation bed 5, thereby preventing the traveling body 21 from coming into contact with the cultivation bed 5.

[0013] According to the fourth aspect of the present invention, the first to third aspects of the present invention In addition to the above effect, the running of the running wheels 35 for running on the transfer passage 4 is stabilized. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a plant cultivation facility for a work vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2A is a side view of the harvesting work vehicle, and FIG. 2B is a plan view of the harvesting work vehicle. [Diagram 3] FIG. 2 is a side view showing an example of harvesting operation in the harvesting work vehicle. [Figure 4] FIG. 4 is an explanatory diagram showing the stacking of buckets in the harvesting vehicle. [Diagram 5] FIG. 2 is a plan view showing the travel means of the work vehicle and its surroundings. [Figure 6] FIG. 2 is a side view showing the travel means of the work vehicle and its surroundings. [Figure 7] FIG. 2 is a control block diagram of the work vehicle. [Figure 8] 2 is a plan view showing a traveling means and a traveling body turning means of the work vehicle. FIG. [Figure 9] 2 is a plan view showing a traveling means and a traveling body turning means of the work vehicle. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A greenhouse system according to an embodiment of the present invention will be described below.

[0016] FIG. 1 shows an example of a cultivation facility, which includes a cultivation room 1, which is a greenhouse in which the indoor environment, such as temperature and humidity, is controlled by heaters and humidifiers, and a shipping room 2 adjacent to the cultivation room 1. In the center of the cultivation room 1, a main passage 4 is provided through which workers, mobile work vehicles (work trolleys) 3, pest control vehicles, etc. can pass, and this main passage 4 is a concrete passage with a concrete road surface. At both sides of the main passage 4, a cultivation space 6 for cultivating crops is formed by arranging a large number of cultivation beds 5, which serve as cultivation units, in rows. The cultivation beds 5 are cultivation beds made of rock wool, which serves as a culture medium, and nutrient solution is supplied to each cultivation bed 5 from a nutrient solution supplying device 7 in the shipping room 2.

[0017] In addition, entrances 8 to the cultivation room 1 equipped with opening and closing doors are provided at both ends of the main passage 4, and one of the entrances 8 can be used to access the adjacent shipping room 2. The other entrance 8 can be used to access the cultivation facility from the outside. The mobile work vehicle 3 can be moved from the main passage 4 to a sub-passage 9 between each cultivation bed 5, and various tasks can be performed on the plants being cultivated while moving the mobile work vehicle 3 along the cultivation beds 5 on the sub-passage 9. The sub-passage 9 is a passage formed in the front-rear direction between the left and right sides of each cultivation bed 5. The mobile work vehicle 3 runs on rails 13 on the left and right heating pipes laid on the sub-passage 9 for heating the entire greenhouse.

[0018] The shipping room 2 is provided with the nutrient solution supplying device 7 and a sorting device 10 that sorts the harvested crops (fruits) such as tomatoes by weight, size, or grade. The sorting device 10 is a pre-treatment device that processes the cultivated crops before shipping. The sorting device 10 is configured with a sorting conveyor 11 that transports and sorts the harvested crops, and harvested product storage sections 12 for each class provided on both sides of the sorting conveyor 11, and is configured to supply the harvested crops from the sorting conveyor 11 to each harvested product storage section 12 and sort them into each class. The sorting conveyor 11 is configured to be bent in an L-shape in a plan view. Each harvested product storage section 12 is provided with a storage box for storing the harvested crops, and the harvested crops are shipped by this storage box.

[0019] An attracting wire 15 is provided on the upper side of the cultivation bed 5 along the cultivation line, and the cultivated plant P is attracted by an attracting string 17 as an attracting member that hangs down from the attracting wire 15 via an attracting hook 16. The attracting hook 16 is configured to be hung from the attracting wire 15, and is configured to appropriately let the wrapped attracting string 17 hang down, as is well known. After the plant grows to a predetermined height (near the attracting hook 16), the attracting string 17 is sequentially shifted in the arrangement direction of the multiple cultivated plants, i.e., in the longitudinal direction of the cultivation bed 5, while letting out the attracting string 17 from the attracting hook 16, to lower the height of the plant, and the plant is continuously cultivated. Therefore, for example, when a tomato f is cultivated, the tomato stem c will extend from the cultivation bed 5 along the attracting string 17 (FIG. 3).

[0020] The mobile work vehicle 3 is a harvesting work vehicle as shown in Figures 2 and 3. A harvesting arm 22 is provided on a traveling body 21 supported for travel by front, rear, left and right traveling wheels 20 so that the traveling body 21 can travel, and a clamping lift mechanism 25, 26 is provided for stacking and unstacking harvest storage buckets A, A... in multiple stages in upper and lower storage spaces 23, 24 formed in the traveling body 21. The harvesting arm 22 and the upper and lower clamping lift mechanisms 25, 26 are configured so that actuators such as control motors are operated in response to command signals output by a control device C which receives setting signals and input signals from various sensors such as an imaging device (not shown), thereby automatically performing operations such as harvesting fruit and storing fruit in the bucket A.

[0021] The buckets A are stacked in the lower storage space 24 of the upper and lower storage spaces 23, 24, and in this state, tomatoes f harvested by the harvesting arm 22 are successively supplied to the topmost bucket A (FIG. 4(a)). When the topmost bucket A is full, the lower clamping lift mechanism 26 lifts the bottommost bucket A, that is, all buckets A, A... rise (FIG. 4(b)). Then, when the topmost bucket A rises to the standby position of the upper clamping lift mechanism 25, the upper clamping lift mechanism 25 engages and lifts the topmost bucket A, so that the topmost bucket A, which contains the tomatoes, waits in the upper storage space 23 (FIG. 4(c)).

[0022] Next, the empty bucket A is fed with the tomatoes f harvested by the harvesting arm 22 until the bucket A at the top of the lower storage space 24 is filled with them. After that, the bucket A supported by the upper clamping lift mechanism 25 is lowered and placed on the full bucket A (Fig. 1(d)), and all the buckets A, A... are raised by the lower clamping lift mechanism 26, and the second top full bucket A is raised while being supported by the upper clamping lift mechanism 25 (Fig. 1(e)). In this way, the buckets A that are successively filled are transferred in a stack to the upper storage space 23. Then, when the bottom bucket A supported by the lower clamping lift mechanism 26 is filled with the harvested tomatoes f (Fig. 1(f)), the harvesting is completed. The bucket A supported by the upper clamping lift mechanism 25 is stacked on this bottom bucket A (Fig. 1(g)), and all the upper buckets A are lowered (Fig. 1(h)). The multi-stage bucket A containing the harvested tomatoes f is then moved to the lower storage space 24. The bucket A waiting in the lower storage space 24 is moved to the outside of the traveling body 21 by appropriately opening the bottom or by conveyor transport means.

[0023] 3, the support base 27 of the harvesting arm 22 is configured to be movable in the front-rear direction of the traveling body 21 by a guide rail 28 provided along the boundary line between the upper and lower storage spaces 23, 24. Therefore, if all the buckets A, A... are positioned in the lower storage space 24, the harvesting arm 22 can be moved forward along the guide rail 28, and the tomatoes f growing on the stems c approaching the building wall 29 can be harvested. Since there are not many harvested tomatoes f, they can be stored in the uppermost bucket A, which already has storage space remaining.

[0024] Next, the traveling mechanism of the mobile work vehicle 3 and its peripheral configuration will be described. As shown in Figures 5 and 6, a pair of traveling wheels 20 on the front, rear, left and right sides that support the traveling body 21 are raceways consisting of large diameter wheels 20a and small diameter wheels 20b, and the small diameter wheels 20b are configured to be able to travel along the rails 13 of the sub-passage 9 (hereinafter referred to as the work passage 9). The large diameter wheels 20a are provided for access travel up to the rails 13 or for retreating travel from the rails 13. The front wheel axles 30 of the pair of front left and right traveling wheels 20 are configured to be driven by a traveling drive motor 31, and the rear wheel axles 32 of the pair of rear left and right traveling wheels 20 and the front wheel axles 30 are interlocked with an endless body 33, so that the traveling wheels 20 are configured to be four-wheel driven.

[0025] The central underside of the traveling body 21 is provided with traveling wheels 35 for traveling on the main passage 4 (hereinafter referred to as the moving passage 4) in the cultivation room 1. The moving passage traveling wheels 35 are rubber wheels, and constitute left and right wheel axles 36, 37 whose rotational axis in a plan view is perpendicular to the front wheel axle 30 and rear wheel axle 32 of the traveling wheels 20 for the working passage, and are supported as a pair on each of these wheel axles 36, 37. The left wheel axle 36 is driven by a traveling drive motor 38, and is configured to be able to travel on the main passage 4 (hereinafter referred to as the moving passage 4) in the cultivation room 1 in two-wheel drive form.

[0026] The left and right wheel axles 36, 37, the moving passage running wheels 35, etc. are arranged to be able to rise and fall by forming a pantograph-type lifting mechanism 39 on the underside of the central part of the traveling body 21. The moving passage running wheels 35 can be lowered by forward rotation of the lifting drive motor 40 of the lifting mechanism 39, and can be raised by reverse rotation of the lifting drive motor 40. The moving passage running wheels 35 can be switched between a running state in which the lifting mechanism 39 is controlled to lower so that the ground contact position of the moving passage running wheels 35 is lower than the lower edge of the moving passage running wheels 20, and a non-running state in which the lifting mechanism 39 is controlled to raise so that the ground contact position of the moving passage running wheels 35 is higher than the lower edge of the running wheels 20.

[0027] A plurality of batteries 41 for various power sources and motor drive are mounted on the traveling body 21, and in the illustrated example, four batteries 41 are arranged symmetrically in the front, rear, left and right directions on the underside of the traveling body 21 to improve the front, rear, left and right balance. That is, the traveling wheels 20 for traveling on the front, rear, left and right work passages 9 and the traveling wheels 35 for traveling on the transfer passage 4 are positioned so as to face each other at each of the four corners at a predetermined distance in the front and rear directions, and the batteries 41 are arranged within this predetermined distance range.

[0028] Next, we will explain the control for determining the entry position of the work passage 9 in the mobile work vehicle 3 when traveling along the travel passage 4. The rails 13 are arranged in two rows in parallel, and the ends 13t formed in a roughly U-shape to circulate hot water on the rails 13 are arranged in multiple rows, and the control device C inputs the detection value of the work passage entry position detection sensor 45 and determines whether or not the entry position has been reached based on the detection of this work passage entry position detection sensor 45. The rail ends 13t are provided at the start side of each work passage 9.

[0029] In the illustrated example, the work passage entry position detection sensors 45L, 45R are provided at two locations, one on the front left and right sides of the traveling body 21, one on the forward direction Fa side and one on the rear direction of the moving passage 4. With this configuration, as the traveling body 21 moves in the moving passage 4, the leading work passage entry position detection sensor 45R detects the left rail 13L, the rail end 13t, and the right rail 13R in that order, and in addition to being able to detect the entry position of the work passage 9 immediately after detecting the right rail 13R, the trailing work passage entry position detection sensor 45L detects the rail 13L and the rail end 13t of the working passage entry position detection sensor 45R normally because there is no rail detection, and contributes to the judgment of the control device C (see FIG. 7), but by detecting the rail 13L and the rail end 13t of the trailing work passage entry position detection sensor 45L, it is possible to detect the overshooting of the traveling body 21. That is, by setting the distance between the left and right work passage entry position detection sensors 45L, 45R large with respect to the distance between the pair of rails 13, it can be determined that the trailing work passage entry position detection sensor 45L detects the rail 13L or the rail end 13t and has overshot. In this case, the travel drive motor 38 is rotated in the reverse direction to move the traveling vehicle body 21 backward until the rail 13L is detected again, so that the proper entry position can be reached. When the control device C determines that the traveling vehicle body 21 traveling on the transfer passage 4 has reached the entry position, it controls the traveling vehicle body 21 to stop. At the same time, it commands the lift drive motor 40 to rotate in the reverse direction, and the transfer passage traveling wheels 35 are raised and interlocked to a non-traveling state, and the device is in a preparation state for entry control into the work passage 9.

[0030] Next, the control device C outputs a forward drive signal to the traveling drive motor 31, which drives the traveling wheels 20, which are track wheels. Therefore, the traveling body 21 moves forward and can move from the transfer passage 4 to the rails 13 of the working passage 9. The traveling body 21 is provided with rail detection sensors 49L, 49R at the rear of the left traveling wheel 20 of the front wheel axle 30 and at the front of the right traveling wheel 20 of the rear wheel axle 32. Therefore, when the traveling body 21 moves normally on the rails 13, it can detect the rails 13 and it is determined that the traveling is normal, but when either or both of them cannot detect the rails 13, it is determined that the traveling wheels 20 are not in a normal traveling state and a derailment or the like is detected.

[0031] In addition, a detectable member 46 is disposed in the center of the rail end 13t. In detail, a detectable rod 46c is erected via an elastic member 46b on a base 46a that straddles the rail end 13t, and the control device C can determine that the vehicle body 21 has reached the entrance of the work passage 9 when the forward detection sensor 47f of the vehicle body 21 traveling on the moving passage 4 detects the detectable rod 46c. In particular, by configuring the forward detection sensor 47f as a distance detection sensor, it can be determined whether the vehicle body 21 is at an appropriate distance from the detectable rod 46c, that is, whether the traveling position of the moving passage 4 is appropriate or not. In addition, when the vehicle body 21 advances along the rail 13 of the working passage 9, the distance to the building wall 48 can be detected, and the vehicle body 21 can be used as a detector for detecting whether the vehicle body 21 is approaching the building wall 48 abnormally. The base 46a of the detectable member 46 is configured to be fixed and released to the rail end 13t by a fastening member 46d, and is provided along the rail end 13t so that the position can be freely adjusted.

[0032] A reverse detection sensor 47r is provided at the rear of the traveling body 21, and by appropriately arranging a detectable member (not shown), the amount of reverse movement when the traveling body 21 is reversed to return from the working passage 9 to the moving passage 4 can be adjusted appropriately, and it can be stopped at an appropriate position on the moving passage 4.

[0033] 8 and 9 show an example of the configuration of the turning mechanism 50 of the traveling body 21A. The pair of left and right traveling wheels 51 are composed of large diameter wheels 51a supported by wheel axles 52 and small diameter raceways 51b supported coaxially. Therefore, the large diameter wheels 51a run on the main passage 4 (hereinafter referred to as the moving passage 4) in the cultivation room 1, and the raceways 51b run along the rails 13 of the sub-passage 9 (hereinafter referred to as the working passage 9). In addition, the front wheel axles 52f of the pair of left and right traveling wheels 51 on the front side are configured to be driven by the traveling drive motor 53. Although not shown in the figure, the rear wheel axles 52r of the pair of left and right traveling wheels 51 on the rear side and the front wheel axles 52f may be interlocked with an endless body (not shown) to configure the traveling wheels 51 to be four-wheel driven.

[0034] The traveling body 21A is configured so that the direction of the traveling body 21A can be changed by 90 degrees by a turning mechanism 50 described later between a direction along the travel path 4 and a direction along the rails 13 that can enter the work path 9. When the traveling body 21 is along the travel path 4, it travels on the travel path 4 using the wheels 51a, and when it is turned by an angle of 90 degrees, it can travel on the work path 9 using the track wheels 51b along the rails 13.

[0035] In the turning mechanism 50, a large diameter gear 55 is fixed to the central lower part of the traveling body 21A, and a small diameter gear 56 that meshes with the large diameter gear 55 is provided. A magic hand type multi-joint link mechanism 57 is configured on the underside of the large diameter gear 55, and a disk 59 connected to the lower part of the multi-joint link mechanism 57 can be adjusted to have a larger or smaller gap between the large diameter gear 55 and the disk 59 by the expansion and contraction operation of a hydraulic cylinder mechanism 58.

[0036] Therefore, the traveling body 21A travels on the large diameter wheels 51a along the transfer passage 4 and is controlled to stop when it reaches the entry position of the working passage 9. Then, when the hydraulic cylinder mechanism 58 is switched from the retracted position to the extended position, the disk 59 touches the ground and is further extended by the supply of pressure oil to the hydraulic cylinder mechanism 58, allowing the traveling body 21A to float (phantom line in FIG. 9).

[0037] The traveling body 21A is equipped with a turning drive motor 60 that drives the small diameter gear 56, and when the motor 60 is driven, the large diameter gear 55 is interlocked, and the traveling body 21A in the floating state rotates together with the large diameter gear 55 about the vertical center line P of the large diameter gear 55, and when the motor 60 is stopped at a position where it has rotated approximately 90 degrees, the traveling body 21A enters a turning state along the rail 13 of the working passage 9. By contracting the hydraulic cylinder mechanism 58 at this position, the disk 59 is raised and retracted to a stored position, and the traveling wheels 20 return to a grounded state. When the traveling body 21A advances and reaches the end of the rail 13, the track wheel 51b rests on the rail 13 and can travel.

[0038] As described above, the large diameter gear 55 provided in the center of the working vehicle body 21A is configured to rotate the entire traveling vehicle body 21A, which is lifted by the turning drive motor 60, about the vertical axis, so that the working vehicle body 21A can be turned stably. [Explanation of symbols]

[0039] 4. Passageway 5. Cultivation Beds 9 Work passage 13 Rail 13t Rail end 20b Raceway ring 21 Working vehicle 35 wheels 39 Lifting mechanism 41 Battery 45 Work passage entrance position detection sensor 46 Detectable member 47f Forward detection sensor 47r Reverse detection sensor

Claims

1. In a work vehicle that travels on each of the work passages (9) between a large number of cultivation beds (5) and on a moving passage (4) that leads to each of the work passages (9) at the end of the cultivation beds (5), a traveling body (21) is provided with raceways (20b) that travel on a pair of left and right rails (13) arranged on each of the work passages (9) and wheels (35) that travel on the moving passage (4), and the wheels (35) that travel on the moving passage (4) are provided so as to be switchable between a running state in which they are in contact with the ground and a raised, non-running state by a lifting mechanism (39); A work passage entry position detection sensor (45L, 45R) is provided on each of the left and right front parts of the traveling vehicle body (21), As the traveling vehicle body (21) moves along the travel passage (4) by the wheels (35), the preceding work passage entry position detection sensor (45R) detects the rail (13L) closer to the direction of travel and then the rail (13R) farther from the direction of travel, and when it detects the rail (13R) farther from the direction of travel, it can detect the entry position of the work passage (9), This work vehicle is characterized in that the distance between the left and right work aisle entry position detection sensors (45L, 45R) is greater than the distance between the pair of rails (13) so that the control unit can detect the traveling vehicle body (21) going too far by the trailing work aisle entry position detection sensor (45L) detecting the rail (13L) closer to the traveling direction of travel after the leading work aisle entry position detection sensor (45R) has detected the rail (13R) farther from the traveling direction of travel.

2. A work vehicle as described in claim 1, characterized in that when the control unit detects that the traveling body (21) has gone too far, it drives the wheels (35) to reverse the traveling body (21) and reach the entry position.

3. A pair of rails (13) are provided with end portions (13t) formed in a substantially U-shape, the end portions (13t) are provided on the starting end side of each working passage (9), and a detectable member (46) is provided in the center of the left and right portions; 3. The work vehicle according to claim 1, wherein a forward movement detection sensor (47 f) is provided in the left-right center of the traveling body (21), and when the forward movement detection sensor (47 f) detects the detected member (46), the control unit determines that the entrance to the work passage (9) has been reached.

Images