Work vehicle

Abstract

To allow a pressing part to track for the uneven soil and inhibit weeds from growing appropriately.SOLUTION: A work vehicle 1 includes: a vehicle body 11; wheels 212a and 212b that support the vehicle body so as to cause it to travel; driving devices 311a and 311b mounted on the vehicle body for rotationally driving the wheels; and a weed processing device 41 mounted on the vehicle body. The weed processing device 41 includes a plurality of pressing parts (pressing rollers 411) disposed aligned in a vehicle width direction Dw of the vehicle, and a support mechanism 41 for supporting the plurality of pressing parts for the vehicle so as to move them along the soil and to press the weeds against the soil when the vehicle travels. The support mechanism 41 supports the plurality of pressing parts so as to displace them in a vertical direction with respect to the vehicle body independently of each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a work vehicle used for treating weeds in farm fields and the like. [Background technology]

[0002] Conventional work vehicles used for removing weeds are generally equipped with a cylindrical roller, which is dragged across the soil to press the weeds into the soil and inhibit their growth.

[0003] Patent document 1 describes a work vehicle that has wheels for running on each side of the body, as well as cylindrical rollers that are arranged below the body and have a rotating shaft between the front and rear ends of the body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-077241 A Summary of the Invention [Problem to be solved by the invention]

[0005] With this type of structure, the roller cannot follow the unevenness of the soil and cannot press the weeds into the soil in places the roller cannot reach, so it may be difficult to sufficiently inhibit the growth of weeds. This problem is particularly noticeable in land with a lot of unevenness in the soil, such as farm fields, where the roller often lifts up.

[0006] In view of the above circumstances, an object of the present invention is to provide a work vehicle that allows a pressing part to conform to uneven soil and effectively inhibit the growth of weeds. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, a work vehicle according to one embodiment of the present invention comprises a vehicle body, wheels that support the vehicle body so that it can run, a drive unit mounted on the vehicle body and that drives and rotates the wheels, and a weed treatment device attached to the vehicle body, wherein the weed treatment device comprises a plurality of pressing parts arranged in a line in the width direction of the vehicle, and a support mechanism that supports the vehicle body so that the plurality of pressing parts can move along the soil and can press weeds against the soil when the vehicle is running, and the support mechanism supports the plurality of pressing parts so that they can be displaced independently of each other in the vertical direction relative to the vehicle body. Effect of the Invention

[0008] According to one embodiment of the present invention, the weeds can be treated by pressing the weeds against the soil with a plurality of pressing parts provided in the weed treatment device and inhibiting their growth. Furthermore, the plurality of pressing parts can be made to independently follow the uneven soil, thereby effectively inhibiting the growth of the weeds. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view of a work vehicle according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 4 is an explanatory diagram showing a turning radius of the work vehicle. [Figure 6] 3 is a configuration diagram of a support mechanism (movable support portion) provided in the work vehicle. FIG. [Figure 7] FIG. 11 is a plan view of a work vehicle according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (Overall configuration of the work vehicle) Figures 1 to 3 show the overall configuration of a work vehicle 1 according to one embodiment of the present invention, with Figure 1 being a side view of the work vehicle 1 as seen from the right side, Figure 2 being a rear view as seen from behind, and Figure 3 being a plan view as seen from above.

[0012] The work vehicle 1 is used to treat weeds in fields and the like. In this embodiment, "treating weeds" refers to a process of affecting and inhibiting the growth of weeds by pressing them against the soil. This does not completely remove the weeds, but rather maintains a state in which the weeds, whose height has been suppressed by inhibiting their growth, cover the surface of the soil to an appropriate extent. When used in a field, the work vehicle 1 is driven along a groove formed between adjacent ridges, and the weeds growing in the groove are pressed against the soil by a pressing roller 411 provided in the weed treatment device 1, thereby treating the weeds. In addition to treating weeds, the work vehicle 1 can also be used to transport luggage by installing a loading platform on the vehicle body 11, or to form a pedestal and use it for transporting people. Furthermore, the work vehicle 1 can also be used to treat weeds on land other than a field. The work vehicle 1 used to treat weeds in a field may be referred to as a "field work vehicle" below.

[0013] A work vehicle (hereinafter simply referred to as "vehicle") 1 comprises a vehicle body 11, wheels 21, a drive unit 31, and a weed treatment device 41 as basic components.

[0014] The vehicle body 11 includes a pair of left and right side members 111a, 111b extending in the front-rear direction Dl of the vehicle 1, and a plurality of cross members 112a, 112b, 112c extending in the vehicle width direction Dw.

[0015] The left and right side members 111a, 111b are spaced apart from each other in the vehicle width direction Dw and are arranged at the right and left ends of the vehicle 1 (hereinafter, the side member at the left end will be referred to as the "left side member" 111a, and the side member at the right end will be referred to as the "right side member" 111b).

[0016] The cross members 112a, 112b, 112c are spaced apart from each other in the front-rear direction Dl and are arranged to span between the side members 111a, 111b. The cross members 112 include a front cross member 112a arranged at the front end of the vehicle 1, a rear cross member 112b arranged at the rear end, and an intermediate cross member 112c arranged between the front cross member 112a and the rear cross member 112b. The number of cross members 112 is not limited to three, and any appropriate number can be provided. The cross members 112 (112a, 112b, 112c) are connected to the side members 111 (111a, 111b) to form the skeletal structure of the vehicle 1.

[0017] In this embodiment, in order to increase the strength of the skeleton structure, reinforcing members 113 (113a, 113b, 113c) are provided which extend parallel to the side members 111a, 111b and connect the front cross member 112a, the rear cross member 112b, and the middle cross member 112c to one another. As with the cross member 112, the number of reinforcing members 113 may be any appropriate number other than three. Here, the side members 111, the cross members 112, and the reinforcing members 113 as a whole form a ladder-shaped skeleton structure (i.e., a vehicle body frame).

[0018] The wheels 21 include a pair of left and right wheels provided at the front of the vehicle 1, that is, a left front wheel 211a and a right front wheel 211b, and a pair of left and right wheels provided at the rear of the vehicle 1, that is, a left rear wheel 212a and a right rear wheel 212b. The left front wheel 211a and the left rear wheel 212a are disposed below the left side member 111a, and the right front wheel 211b and the right rear wheel 212b are disposed below the right side member 111b. In this manner, the wheels 21 support the vehicle body 11 so that it can travel in a field. In this embodiment, the front wheels 211 (211a, 211b) have a smaller diameter than the rear wheels 212 (212a, 212b). When the vehicle 1 travels on flat ground, the upper surface of the vehicle body 11 is parallel to the ground.

[0019] The drive device 31 is composed of drive motors 311 (311a, 311b) which are electric motors. The drive motors 311a, 311b are provided for the left rear wheel 212a and the right rear wheel 212b, respectively, and are supported by brackets (not shown) on the vehicle body 11. That is, in this embodiment, the rear wheels 212a, 212b are drive wheels of the vehicle 1, and the front wheels 211a, 211b are driven wheels.

[0020] The drive motors 311a, 311b are capable of independent current control and can supply power independently and individually to the left rear wheel 212a and the right rear wheel 212b. Specifically, the left rear wheel 212a and the right rear wheel 212b can be rotated at equal speeds, one can be rotated at a slower speed than the other, or one can be rotated at the same or different speeds in the opposite direction to the other.

[0021] (Configuration of weed treatment device) The weed treatment device 41 is attached to the rear end of the vehicle body 11 and moves following the vehicle 1 when moving forward to treat weeds. The weed treatment device 41 comprises a plurality of pressing parts 411 arranged side by side in the vehicle width direction Dw of the vehicle 1, and a support mechanism 412 that supports each of the plurality of pressing parts 411 on the vehicle body 11. The weed treatment device 41 may be either non-detachable from the vehicle body 11 or detachable. Removable attachment may be achieved by, for example, making it possible to detachably connect a first support member 4121a and a fourth support member 4121d of the fixed support part described below to the vehicle body 11.

[0022] The pressing portion 411 is configured by a roller member (hereinafter referred to as "pressing roller"). The pressing roller 411 has a rotation axis oriented in the horizontal direction and is rotatable in association with the movement of the vehicle 1. In this embodiment, the pressing roller 411 is a free wheel and can be rotated about an axis extending in the vertical direction Dv to change the orientation of the rotation axis. The pressing roller 411 has a smaller diameter and a narrower width than the rear wheels 212 of the vehicle 1. However, the pressing roller 411 can also be formed to have a smaller diameter and a narrower width than both the front wheels 211 and the rear wheels 212.

[0023] The support mechanism 412 supports the pressing roller 411 so as to be movable along the soil. In other words, the support mechanism 412 supports the pressing roller 411 at a height at which the pressing roller 411 comes into contact with the soil, and the pressing roller 411, while being supported by the support mechanism 412, can press the weeds against the soil.

[0024] In this embodiment, weeds are treated by the pressing roller 411 mainly by the action of gravity acting on the pressing roller 411 itself and the movable member 4122a that can move together with the pressing roller 411. The pressing rollers 411 have equal weights. This allows the multiple pressing rollers 411 to normally press the weeds into the soil with equal pressure. The effect of the pressing roller 411 on the growth of the weeds, that is, the pressure with which the weeds are pressed into the soil, can be adjusted individually for each pressing roller 411 by changing the number of weights W that can be attached to the movable member 4122a or the weight per weight.

[0025] (Details of the support mechanism) The support mechanism 412 has a fixed support part 4121 and a movable support part 4122. The fixed support part 4121 and the movable support part 4122 cooperate with each other to support the pressing roller 411 relative to the vehicle body 11, and the fixed support part 4121 determines the position of the multiple pressing rollers 411 relative to the vehicle body 11 in the front-rear direction Dl and the vehicle width direction Dw of the vehicle body 11. In contrast, the movable support part 4122 allows the multiple pressing rollers 411 to be displaced in the up-down direction Dv relative to the vehicle body 11.

[0026] The movable support portion 4122 has a plurality of movable members 4122a coupled to the pressure roller 411 and movable together with the pressure roller 411, and a plurality of guide members 4122b configured to receive the movable members 4122a respectively and defining the movement direction of the movable members 4122a.

[0027] The movable member 4122a is rod-shaped and is installed vertically or nearly vertically to the soil. The movable member 4122a has one end, specifically, the lower end close to the soil, attached with the pressure roller 411 in a state in which it can rotate freely around a vertical axis. The movable members 4122a are provided individually for the multiple pressure rollers 411, and the movable members 4122a and the pressure rollers 411 are in a one-to-one relationship and are the same in number.

[0028] The guide member 4122b has a cylindrical shape and has an inner diameter slightly larger than the outer diameter of the movable member 4122a. The guide member 4122b can coaxially receive the movable member 4122a therein, and the movable member 4122a is in a state where it can move freely in the vertical direction Dv while being restrained by the guide member 4122b.

[0029] Here, the movable member 4122a is formed with a screw groove into which a nut W can be attached, and by increasing or decreasing the number of nuts W attached to the screw groove, the weight of the pressing roller 411 and the movable member 4122a as a whole can be adjusted, and the pressure applied to the soil via the pressing roller 411, in other words, the pressure pressing the weeds against the soil, can be adjusted. The movable member 4122a is not substantially restrained upward relative to the guide member 4122b and is free to move, while its downward movement is restricted by the abutment between the nut W and the guide member 4122b.

[0030] The fixed support part 4121 is attached to the rear end part of the vehicle body 11 and fixes the guide member 4122b to the vehicle body 11. The guide member 4122b is fixed to the vehicle body 11 by the fixed support part 4121, and the movable member 4122a is in a state in which it is freely movable in the up-down direction Dv inside the guide member 4122b, so that the position of the pressing roller 411 in the front-rear direction Dl and the vehicle width direction Dw relative to the vehicle body 11 is determined by the fixed support part 4121, and the displacement of the pressing roller 411 in the up-down direction Dv relative to the vehicle body 11 is permitted by the movable support part 4122.

[0031] In this embodiment, the fixed support part 4121 has a first support member 4121a, a second support member 4121b, a third support member 4121c, and a fourth support member 4121d. Each of the members 4121a, 4121b, 4121c, and 4121d constituting the fixed support part 4121 has a hollow rod or bar shape and has the same or approximately the same diameter.

[0032] The first support member 4121a is coupled at one end to the rear end of the vehicle body 11 and extends upward from this end. That is, the first support member 4121a stands upright on the upper surface of the rear end of the vehicle body 11. The first support members 4121a correspond to the respective guide members 4122b of the movable support part 4122 and are provided parallel to the guide members 4122b. The first support members 4121a and the guide members 4122b have a one-to-one relationship and are the same in number.

[0033] The second support member 4121b is coupled at one end to a plurality of (two in this embodiment) parts spaced apart above and below the first support member 4121a, and extends from each part perpendicularly to the first support member 4121a toward the rear of the vehicle body 11. The second support member 4121b is coupled at the other end to the guide member 4122b of the movable support part 4122. In other words, the second support member 4121b functions as an intermediate member that connects the first support member 4121a and the corresponding guide member 4122b, and prevents the guide member 4122b from rotating about an axis extending in the vehicle width direction Dw and an axis extending in the front-rear direction Dl.

[0034] In this manner, the engaging member 4122b of the movable support portion 4122 is fixed to the vehicle body 11 via the first and second support members 4121a, 4121b of the fixed support portion 4121.

[0035] The third and fourth support members 4121c, 4121d strengthen the connection between the first support member 4121a and the vehicle body 11, and reinforce the fixing strength of the guide member 4122b by the fixed support part 4121.

[0036] The third support member 4121c extends in the vehicle width direction Dw, and is coupled to the upper ends of the plurality of first support members 4121a to connect the first support members 4121a.

[0037] The fourth support members 4121d are provided on the left and right sides, one end of which is coupled to the left end and the right end of the third support member 4121c, respectively, and the other end of which is coupled to the vehicle body 11. That is, the fourth support member 4121d indirectly couples the first support member 4121a to the vehicle body 11 with the third support member 4121c interposed therebetween. In this way, the first support member 4121a is directly coupled to the vehicle body 11 at one end (i.e., the lower end), and is coupled to the vehicle body 11 at the other end (i.e., the upper end) via the third and fourth support members 4121c and 4121d, thereby suppressing tilt in the front-rear direction Dl.

[0038] Furthermore, the fourth support members 4121d are provided on the left and right sides, and are disposed diagonally with respect to the front-rear direction Dl. The left and right fourth support members 4121d have their joints with the vehicle body 11 located more inward in the vehicle width direction Dw than the joints with the third support member 4121c. In this way, the fourth support member 4121d is connected to the third support member 4121c while being disposed diagonally, thereby suppressing displacement of the third support member 4121c in the vehicle width direction Dw, and maintaining the first support member 4121a in a straight upright state.

[0039] (Explanation of action and effect) FIG. 4 is an explanatory diagram of the operation of the vehicle 1 in a farm field.

[0040] 4 shows how weeds growing in a furrow formed between ridges H in a farm field are treated by a vehicle 1. When treating the weeds, the vehicle 1 travels along the furrow in the direction in which the furrow extends. During this process, the pressure roller 411 of the weed treatment device 41 presses the weeds against the soil, inhibiting their growth, thereby making it possible to treat the weeds.

[0041] Here, the fixed support parts 4121 of the support mechanism 412 determine the position of the pressure rollers 411 relative to the vehicle body 11 in the front-rear direction Dl and the vehicle width direction Dw of the vehicle 1, while the movable support parts 4122 allow the pressure rollers 411 to be displaced in the up-down direction Dv relative to the vehicle body 11 independently of each other. Fig. 4 shows a state in which the leftmost pressure roller 411 and the rightmost pressure roller 411 in the traveling direction of the vehicle 1 ride up the side of the ridge H and move upward, while the central pressure rollers 411 are on the bulge of the groove and move slightly upward.

[0042] In this way, each of the multiple pressure rollers 411 can independently follow the uneven soil, making it possible to effectively inhibit the growth of weeds.

[0043] By forming a pressing section using pressure rollers 411 and rotatably supporting a plurality of pressure rollers 411 using a support mechanism 412, the contact area of ​​the pressure rollers 411 with the soil can be kept small, so that the weeds can be firmly pressed against the soil and their growth can be inhibited more reliably.

[0044] By making each of the multiple pressing rollers 411 equal in weight, it becomes possible to press the weeds evenly against the soil with equal pressure regardless of their position in the vehicle width direction Dw. Furthermore, the weight balance in the vehicle width direction Dw of the entire vehicle 1 including the vehicle body 11 and the weed treatment device 41 can be easily maintained, allowing the vehicle 1 to travel stably even on an uneven field, and to efficiently treat weeds and perform other tasks.

[0045] Furthermore, by making it possible to individually adjust the weight of the pressure roller 411 and the movable member 4122a as a whole, it is possible to individually adjust the pressure applied to the soil via the pressure roller 411 according to the shape of the unevenness and the growth state of the weeds, and to more effectively inhibit the growth of weeds by making the pressure roller 411 follow the soil.

[0046] FIG. 6 is a configuration diagram of the support mechanism 412 (movable support portion 4122) provided in the vehicle 1. As shown in FIG.

[0047] In this embodiment, a weight W that can be attached to the movable member 4122a of the movable support part 4122 is used to adjust the pressure when pressing the weeds against the soil. Specifically, a nut that can be screwed into a thread groove formed in the movable member 4122a is used as the weight W, and by increasing or decreasing the number of these nuts W, the weight of the entire pressing roller 411 and the movable member 4122a is increased or decreased, thereby adjusting the pressure applied to the soil via the pressing roller 411. FIG. 6 shows a state in which three nuts W are attached to the movable member 4122a.

[0048] The adjustment of the pressure applied to the soil is not limited to this, and a weight other than a nut may be used, or it is also possible to increase or decrease the weight of the movable member 4122a instead of a weight. For example, the movable member 4122a may be configured to be divisible, and the weight of a part may be increased or the length of a part may be extended. Furthermore, the part of the movable member 4122a to which the weight is attached is not limited to the outside of the guide member 4122b, but may be the inside.

[0049] By configuring the pressing roller 411 as a swivel wheel that can rotate around the vertical axis Dv, when turning the vehicle 1 around the vertical axis Dv (i.e., making a pivot turn), the orientation of the pressing roller 411 can be easily made to follow the movement of the vehicle 1, and it is possible to avoid a situation in which an excessive load is applied to the soil via the pressing roller 411. This makes it possible to prevent the soil from being damaged by the removal of weeds and to maintain the soil in good condition.

[0050] The wheels 21 are front wheels 211 (211a, 211b) and rear wheels 212 (212a, 212b), with the rear wheels 212 being drive wheels and the front wheels 211 being driven wheels. The pressure rollers 411 are positioned behind the rear wheels 212 in the direction of travel of the vehicle 1, so that turning is performed around the rear wheels 212, which are the drive wheels, and it is possible to keep the turning radius of the entire vehicle 1, including the weed treatment device 41, small.

[0051] FIG. 5 is an explanatory diagram showing the turning radius of the vehicle 1 when making a sharp turn.

[0052] The turning radius of the vehicle 1 when the rear wheels 212 are the drive wheels is determined by the larger of the dimension Da from the rear wheels 212 to the front end of the vehicle body 11 and the distance from the rear wheels 212 to the pressure roller 411. In this embodiment, the distance between the rear wheels 212 and the pressure roller 411 is narrower than the distance between the rear wheels 212 and the front wheels 211, and the turning radius is determined by the dimension Da. In contrast, when the front wheels 211 are the drive wheels and turning is performed around the front wheels 211, the turning radius is determined by the distance Db between the front wheels 211 and the pressure roller 411. Therefore, by making the dimension from the front wheels 211 to the front end of the vehicle body 11 shorter than the distance between the rear wheels 212 and the pressure roller 411, the turning radius when the rear wheels 212 are the drive wheels can be kept smaller than when the front wheels 211 are the drive wheels, and it is possible to realize running with good maneuverability in a farm field.

[0053] The pressure roller 411 is axially supported by a movable member 4122a extending in the vertical direction, and the movable member 4122a can be guided in the vertical direction by a guide member 4122b. Furthermore, the guide member 4122b is fixed to the vehicle body 11 by the fixed support part 4121. This makes it possible to achieve movement of the pressure roller 411 in accordance with the soil and support of the pressure roller 411 by the support mechanism 412 with a relatively simple configuration.

[0054] By providing a first support member 4121a and a second support member 4121b on the fixed support portion 4121 and connecting the second support member 4121b to multiple locations spaced apart above and below the first support member 4121a and connecting the first support member 4121a and the guide member 4122b via the second support member 4121b, it is possible to firmly support the guide member 4122b of the movable support portion 4122 and in particular to prevent misalignment in the fore-and-aft direction Dl and the vehicle width direction Dw from occurring in the position of the pressure roller 411 relative to the vehicle body 11.

[0055] Furthermore, the first support member 4121a, which is connected to the rear end of the body 11 and extends upward, can prevent objects such as luggage placed on the body 11 from falling backward of the vehicle 1.

[0056] By providing a third support member 4121c extending in the vehicle width direction Dw, and connecting the upper ends of the first support member 4121a to each other via the third support member 4121c, and connecting each of the two ends of the third support member 4121c to the vehicle body 11 via the fourth support member 4121d, the first support member 4121a is supported more firmly, thereby making it possible to support the guide member 4122b more reliably and firmly by the fixed support portion 4121.

[0057] Furthermore, the fourth support member 4121d connecting both ends of the third support member 4121c to the vehicle body 11 can prevent the load such as luggage placed on the vehicle body 11 from falling off the side of the vehicle. In this way, the first support member 4121a and the fourth support member 4121d surround the top surface of the vehicle body 11 from the rear and the left and right sides, allowing the load to be transported safely.

[0058] The fourth support member 4121d may be at a position where a joint portion between the fourth support member 4121d and the vehicle body 11 is fixed in the vehicle width direction Dw, or may be displaceable. A case where the joint portion between the fourth support member 4121d and the vehicle body 11 is movable in the vehicle width direction Dw will be described below.

[0059] (Description of Other Embodiments) FIG. 7 is a plan view of a vehicle 1 according to another embodiment of the present invention.

[0060] In this embodiment, the fourth support member 4121d connecting the third support member 4121c and the vehicle body 11 has an extension mechanism for responding to a change in the distance between a joint with the third support member 4121c and a joint with the vehicle body 11. This extension mechanism operates to shorten the length of the fourth support member 4121d when the joint with the vehicle body 11 of the fourth support member 4121d is displaced outward. Figure 7 shows the fourth support member with the joint with the vehicle body 11 displaced outward by the reference symbol 4121d'.

[0061] In this way, by making the joint portion of the fourth support member 4121d with respect to the vehicle body 11 displaceable in the vehicle width direction Dw, it is possible to expand the space available for loading luggage, etc. in the vehicle body 11 and improve the convenience of the vehicle 1, while maintaining the original function of the fourth support member 4121d, that is, to make the support of the guide member 4122b by the fixed support portion 4121 more reliable and firm by strengthening the support of the first support member 4121a, thereby improving the convenience of the vehicle 1. In Fig. 7, the space available for loading luggage, etc. is shown typically by a two-dot chain line. [Explanation of symbols]

[0062] 1...work vehicle, 11...vehicle body, 111a, 111b...side members, 112a, 112b, 112c...cross members, 113a, 113b, 113c...reinforcing members, 21...wheels, 211...front wheels, 212a...left front wheel, 212b...right front wheel, 212...rear wheels, 212a...left rear wheel, 212b...right rear wheel, 31...drive mechanism, 311a, 311b ...electric motor, 41...weed treatment device, 411...pressing section (pressing roller), 412...support mechanism, 4121...fixed support section, 4121a...first support member, 4121b...second support member, 4121c...third support member, 4121d...fourth support member, 4122...movable support section, 4122a...movable member, 4122b...guide member, W...weight, H...ridge.

Claims

1. The car body and Wheels that support the vehicle body so that it can run; A drive device mounted on the vehicle body and configured to rotate the wheels; A weed treatment device attached to the vehicle body, The weed treatment device comprises: A plurality of pressing portions arranged in a vehicle width direction of the vehicle; a support mechanism that supports the plurality of pressing parts on the vehicle body so that the pressing parts can move along the soil and press weeds against the soil when the vehicle is traveling; The support mechanism supports the multiple pressing portions so that they can be displaced independently from one another in the vertical direction relative to the vehicle body.

2. The support mechanism includes: A fixed support portion that determines positions of the pressing portions relative to the vehicle body in a front-rear direction and a vehicle width direction of the vehicle; The work vehicle according to claim 1 , further comprising: a movable support portion that allows displacement of the plurality of pressing portions relative to the vehicle body in the vertical direction.

3. The plurality of pressing units include a plurality of pressing rollers, The work vehicle according to claim 2 , wherein the support mechanism rotatably supports the plurality of pressure rollers.

4. The pressure rollers have equal weights, The work vehicle according to claim 3 , wherein the support mechanism is capable of pressing the weeds against the soil with equal pressure between the plurality of pressing rollers.

5. The work vehicle according to claim 3 , wherein the movable support portion is capable of individually adjusting the pressure applied to the soil via the plurality of pressure rollers for each of the pressure rollers.

6. 4. The work vehicle according to claim 3, wherein the pressure rollers are each constituted by a swivel wheel and are rotatable independently of one another about an axis extending in the vertical direction.

7. The wheels include front wheels and rear wheels, the drive device is configured to be capable of transmitting power only to the rear wheels among the front wheels and the rear wheels, The work vehicle according to claim 3 , wherein the pressure rollers are disposed rearward of the rear wheels in a front-to-rear direction of the vehicle.

8. The movable support portion is A plurality of movable members each extending in a vertical direction and rotatably supporting the plurality of pressure rollers at one end thereof; a plurality of guide members that guide the plurality of movable members so as to be movable in the up and down direction, The work vehicle according to claim 3 , wherein the fixed support portion fixes each of the plurality of guide members to the vehicle body.

9. The fixed support portion is a first support member having one end connected to a rear end of the vehicle body and extending upward from the one end; 9. The work vehicle according to claim 8, further comprising: a second support member coupled at one end to a plurality of locations spaced apart above and below the first support member, extending rearward from each of the locations and coupled to each of the plurality of guide members.

10. The fixed support portion is a third support member extending in the vehicle width direction and coupled to an upper end of the first support member; 10. The work vehicle according to claim 9, comprising: a pair of fourth support members each connected at one end to each end of the third support member and each connected at the other end to the vehicle body.

Images