Work vehicles

Abstract

To provide a technique which can increase types of towable bodies which can be towed by a work vehicle.SOLUTION: An exemplary work vehicle is provided in a manner that the work vehicle can tow a towable body placed rearward of a vehicle body and includes: a hitch part which is connected to the towable body; and a support part which is attached to the vehicle body and supports the hitch part. The work vehicle is provided with a height adjustment mechanism which enables adjustment of a support height of the hitch part by the support part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a work vehicle.

Background Art

[0002] Conventionally, a work vehicle is known in which a work device can be connected to the rear using a towing member (see, for example, Patent Document 1). One end of the towing member is connected to a towing hitch provided at the rear of the work vehicle. The other end of the towing member is connected to the work device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, there are various types of towed bodies towed by work vehicles. Also, the sizes of the towed bodies vary. The height position where the towing member is attached may change depending on the type and size of the towed body. It is not preferable that the type of towed body that the work vehicle can tow is reduced due to the difference in the height position where the towing member is attached.

[0005] In view of the above points, an object of the present invention is to provide a technique that can increase the types of towed bodies that can be towed by a work vehicle as much as possible.

Means for Solving the Problems

[0006] An exemplary work vehicle of the present invention is a work vehicle provided to be able to tow a towed body disposed behind the vehicle body, and includes a hitch portion connected to the towed body and a support portion attached to the vehicle body and supporting the hitch portion. A height adjustment mechanism is provided that enables adjustment of the support height of the hitch portion by the support portion. [Effects of the Invention]

[0007] According to the exemplary present invention, the variety of towable towable objects can be increased as much as possible. [Brief explanation of the drawing]

[0008] [Figure 1] Side view showing the general configuration of the work vehicle. [Figure 2] A perspective view showing the approximate configuration of the transmission case and surrounding area of ​​a work vehicle. [Figure 3] A side view showing the general configuration of the traction unit and its surrounding area in the first embodiment. [Figure 4] A perspective view showing the schematic configuration of the traction unit of the first embodiment. [Figure 5] Exploded perspective view showing the schematic configuration of the traction unit of the first embodiment. [Figure 6] A side view showing the general configuration of the traction unit and its surrounding area in the second embodiment. [Figure 7] Exploded perspective view showing the schematic configuration of the traction unit in the second embodiment. [Figure 8] A side view showing the general configuration of the traction unit and its surrounding area in the third embodiment. [Figure 9] A schematic perspective view showing the hitch and support parts that constitute the towing section of the third embodiment, disassembled. [Figure 10] A schematic perspective view showing the first support part and the second support part, which constitute the support part of the third embodiment, in an exploded view. [Figure 11] Figure 8 illustrates a case where the towed object is towed at a different towing height. [Modes for carrying out the invention]

[0009] Hereinafter, a work vehicle according to an embodiment of the present invention will be described with reference to the drawings.

[0010] In this specification, directions are defined as follows: First, the direction in which the work vehicle moves during operation is defined as "forward," and the opposite direction is defined as "rear." Also, the right side of the work vehicle in the direction of operation is defined as "right," and the left side is defined as "left." Furthermore, the direction perpendicular to the front-rear and left-right directions of the work vehicle is defined as the up-down direction. In this case, the direction of gravity is defined as "down," and the opposite side is defined as "up." The above directions are merely descriptive terms and are not intended to limit the actual positional relationships or directions.

[0011] <1. Overview of work vehicles> Figure 1 is a side view showing a schematic configuration of a work vehicle 1 according to an embodiment of the present invention. Figure 1 shows the left side of the work vehicle 1. The work vehicle 1 is equipped to tow a towed body 100 (see Figure 3, etc.) located at the rear of the vehicle body 2. The work vehicle 1 is equipped to perform agricultural work or other tasks while towing the towed body 100. The towed body 100 may be, for example, a trailer or a work machine. The work machine may be agricultural machinery or construction machinery, etc. In this embodiment, the work vehicle 1 is a tractor for agricultural work.

[0012] A pair of front wheels 3 are positioned at the front of the vehicle body 2. A pair of rear wheels 4 are positioned at the rear of the vehicle body 2. The vehicle body 2 is able to move using the front wheels 3 and rear wheels 4. In other words, the work vehicle 1 of this embodiment is a wheel tractor. However, the work vehicle 1 is not limited to a wheel tractor, but may also be a crawler tractor equipped with crawlers, etc.

[0013] An engine 6, covered by a hood 5, is located at the front of the vehicle body 2. The engine 6 is the power source for the work vehicle 1. In this embodiment, the engine 6 is a diesel engine, but it may also be a gasoline engine. The power source for the work vehicle 1 may be another power source, such as an electric motor, instead of the engine. Below the engine 6 at the front of the vehicle body 2, a front axle case (not shown) is located, which includes a front axle 7 that supports a pair of front wheels 3.

[0014] Behind the engine 6, a clutch housing 8 including a clutch (not shown) is connected. Behind the clutch housing 8, a transmission case 9 is arranged. Inside the transmission case 9, a power transmission device (not shown) is arranged. The rotational power of the engine 6 is transmitted to at least one of the front wheels 3 and the rear wheels 4 via the power transmission device in the transmission case 9. On both left and right side surfaces of the transmission case 9, a rear axle case (not shown) including a rear axle 10 that supports a pair of left and right rear wheels 4 is arranged.

[0015] On the rear surface of the transmission case 9, a PTO shaft 11 that can transmit the power from the engine 6 to the outside of the vehicle body 2 is provided. That is, the work vehicle 1 includes a PTO shaft 11 that can transmit the power from the engine 6 mounted on the vehicle body 2 to the outside of the vehicle body 2. Specifically, the PTO shaft 11 protrudes rearward from the rear surface of the transmission case 9. The towed body 100 arranged behind the vehicle body 2 may be configured to receive the transmission of power from the PTO shaft 11.

[0016] Above the clutch housing 8 and the transmission case 9 of the vehicle body 2, a driver's cab 12 is provided. The driver's cab 12 is a part where a driver (operator) rides. The driver's cab 12 has a driver's seat 13 on which the driver sits and a steering wheel 14 arranged in front of the driver's seat 13. Also, the driver's cab 12 has a ROPS 15 at the rear of the driver's seat 13. By providing the ROPS 15, the driver can be protected when the work vehicle 1 overturns. The driver's cab 12 also has other operating levers, pedals, etc.

[0017] In this embodiment, the lifting unit 16 is disposed on the upper surface of the rear portion of the transmission case 9. That is, the work vehicle 1 includes the lifting unit 16 mounted on the vehicle body 2. The lifting unit 16 enables the lifting of a work device (not shown) disposed behind the vehicle body 2. Note that the work device that can be lifted by the lifting unit 16 can also be said to be a towed body because it is towed by the work vehicle 1. However, as will be described in detail later, the towing method of the work device is different from that of the towed body 100 shown in FIG. 3 and the like. For this reason, in this specification, for the work device that can be lifted by the lifting unit 16, for the sake of distinction from the towed body 100 shown in FIG. 3 and the like, it is expediently expressed as a work device rather than a towed body. The work device may be, for example, a plow, a rotary tiller, a disk harrow, a cultivator, or a subsoiler.

[0018] The work device is connected via a three-point link mechanism 17 provided behind the transmission case 9. The three-point link mechanism 17 is composed of a pair of left and right lower links 18 and a top link 19.

[0019] FIG. 2 is a perspective view showing a schematic configuration of the transmission case 9 included in the work vehicle 1 according to the embodiment of the present invention and its periphery. As shown in FIG. 2, the left lower link 18L is rotatably connected at its front end to the rear portion of the left side surface of the transmission case 9 via a lower link pin 20. The right lower link 18R is rotatably connected at its front end to the rear portion of the right side surface of the transmission case 9 via a lower link pin 20. The top link 19 is connected at its front end to a top link attachment portion 21 provided on the rear surface of the lifting unit 16 via a top link pin (not shown). Note that the top link attachment portion 21 is provided so as to be able to adjust the attachment height position of the top link 19.

[0020] The lifting unit 16 has a hydraulic cylinder (not shown) located within the housing that constitutes the unit. As shown in Figures 1 and 2, the lifting unit 16 has a pair of left and right lift arms 22 that are rotatably mounted by the hydraulic cylinder. The pair of lift arms 22 are rotatable around an axis extending in the left-right direction. The left lift arm 22L is connected to the left lower link 18L by a lift rod 23 located on the left side (see Figure 1, omitted in Figure 2). The right lift arm 22R is connected to the right lower link 18R by a lift rod 23 located on the right side. The lift rods 23 are detachable from the lift arms 22 and the lower links 18.

[0021] The working device includes connecting parts that connect to the rear ends of the left and right lower links 18, and connecting parts that connect to the rear end of the top link 19. The working device can be connected to the three-point linkage mechanism 17 using these connecting parts. The left and right lower links 18 are detachable from the transmission case 9. The top link 19 is detachable from the top link mounting part 21. In other words, the left and right lower links 18 and the top link 19 can be attached to and removed from the vehicle body 2 as needed.

[0022] The lifting unit 16 drives the left and right lift arms 22 to rotate. The rotation of the left and right lift arms 22 allows the work device, which is connected via the three-point linkage mechanism 17, to be raised and lowered. The work device can be supported at any height position.

[0023] In this embodiment, a torsion bar 24 is positioned below the top link mounting portion 21. When the traction load generated by the towing of the work device acts on the top link mounting portion 21 via the top link 19, a torsional force is applied to the torsion bar 24 via the top link mounting portion 21. When this torsional force becomes greater than the restoring force of the torsion bar 24, the top link mounting portion 21 swings and displaces from its reference position.

[0024] The lifting unit 16, top link mounting section 21, and torsion bar 24, used in conjunction with the three-point linkage mechanism 17, constitute a draft mechanism 25 that performs known draft control. That is, the work vehicle 1 is equipped with a draft mechanism 25. The draft mechanism 25 adjusts the towing load that pulls the work device, which is positioned at the rear of the vehicle body 2 so as to be able to be raised and lowered by the lifting unit 16. In detail, the draft mechanism 25 raises and lowers the work device according to the towing load and adjusts the towing load to a constant value. For example, the draft mechanism 25 raises and lowers the work device so that the towing load is set by a draft control lever (not shown). With the provision of the draft mechanism 25, tilling work and the like can be performed by towing the work device with a predetermined towing load set by the draft control lever.

[0025] As shown in Figures 1 and 2, the work vehicle 1 is equipped with a towing unit 50 that enables towing without using the three-point linkage mechanism 17, in addition to the three-point linkage mechanism 17 that tows the work equipment described above. The towing unit 50 will be described in detail below.

[0026] <2. Traction part> [2-1. First Example] Figure 3 is a side view showing the schematic configuration of the towing unit 50A and its surrounding area in the first embodiment. Figure 3 also shows the towed body 100 located at the rear of the vehicle body 2. Note that the towing unit 50 shown in Figure 2 is the same as the towing unit 50A of the first embodiment shown in Figure 3. As shown in Figure 3, the towing unit 50A includes a hitch unit 51 and a support unit 52. That is, the work vehicle 1 includes a hitch unit 51 and a support unit 52.

[0027] The hitch section 51 is connected to the towed body 100. More specifically, the hitch section 51 is connected to the towed body 100 via a towing member 53. The front end of the towing member 53 is attached to the hitch section 51. The rear end of the towing member 53 is attached to the towed body 100. In the example shown in Figure 3, the towed body 100 is a work machine. The towed body 100, towed by the work vehicle 1 via the towing member 53, receives power from the PTO shaft 11 via the drive shaft 54 ​​and performs operations for work. The drive shaft 54, whose front end is connected to the PTO shaft 11, is connected, for example, to the gear case of the towed body 100 so as to be able to transmit power at its rear end.

[0028] The towed object 100 may be a trailer, as described above. When a towed object that does not require power transmission from the PTO shaft 11, such as a trailer, is towed by the work vehicle 1, the drive shaft 54 ​​connection does not need to be performed.

[0029] The support portion 52 is attached to the vehicle body 2. More specifically, the support portion 52 is attached to the transmission case 9. The support portion 52 supports the hitch portion 51. That is, the hitch portion 51 is attached to the vehicle body 2 via the support portion 52. In this embodiment, the rear end 52a of the support portion 52 is located in front of the rear end 11a of the PTO shaft 11. With this configuration, the hitch portion 51 supported by the support portion 52 can be positioned as far forward as possible. This makes it possible to shorten the distance L (see Figure 3) between the rear axle 10 and the load position (the connection position between the hitch portion 51 and the towing member 53). As a result, the weights placed on the work vehicle 1 to balance the front and rear weights can be reduced or eliminated.

[0030] Furthermore, the support portion 52 is located in front of the rear end of the top link mounting portion 21 (the rear end 25a of the draft mechanism 25) that constitutes the draft mechanism 25.

[0031] Figure 4 is a perspective view showing the schematic configuration of the towing section 50A of the first embodiment. Figure 5 is an exploded perspective view showing the schematic configuration of the towing section 50A of the first embodiment. Note that the first connecting pin 55 (see Figure 4, etc.) for connecting the hitch section 51 and the support section 52 is omitted in Figure 5. Also, the second connecting pin 56 (see Figure 4, etc.) for connecting the hitch section 51 and the towing member 53 is omitted in Figure 5.

[0032] The hitch portion 51 is a single component formed by processing and welding a metal member such as sheet metal. The method of forming the hitch portion 51 and its shape may be modified as appropriate. The hitch portion 51 may also be configured by connecting multiple members using fasteners such as screws. As shown in Figures 4 and 5, the hitch portion 51 has a rectangular flat hitch base plate 511 that extends in the vertical and horizontal directions.

[0033] Furthermore, the hitch section 51 has a pair of flat front vertical plates 512L and 512R extending forward from the left and right ends of the front surface of the hitch section base plate 511. The pair of front vertical plates 512L and 512R are spaced apart in the left-right direction. The pair of front vertical plates 512L and 512R are identical in shape. The pair of front vertical plates 512L and 512R extend in the front-rear and up-down directions.

[0034] Furthermore, the hitch section 51 has a pair of flat hitch section rear lateral plates 513U and 513L that extend rearward from the upper and lower ends of the rear surface of the hitch section base plate 511. The pair of hitch section rear lateral plates 513U and 513L are spaced apart in the vertical direction. The pair of hitch section rear lateral plates 513U and 513L are identical in shape. The pair of hitch section rear lateral plates 513U and 513L extend in the front-to-back and left-to-right directions.

[0035] Furthermore, the hitch section 51 has a pair of flat hitch section reinforcing plates 514L and 514R located behind the hitch section base plate 511, connecting the left ends and right ends of the pair of hitch section rear lateral plates 513U and 513L, respectively. The pair of hitch section reinforcing plates 514L and 514R are identical in shape. The pair of hitch section reinforcing plates 514L and 514R extend in the front-to-back and up-and-down directions.

[0036] Each of the pair of front vertical hitch plates 512L and 512R has a plurality of hitch adjustment holes 515 that penetrate in the left-right direction. The plurality of hitch adjustment holes 515 are the same shape and size. The hitch adjustment holes 515 are circular in shape when viewed from the left-right direction. In each of the pair of front vertical hitch plates 512L and 512R, the plurality of hitch adjustment holes 515 are arranged at equal intervals in the vertical direction and positioned at the front of the plate. Between the left and right front vertical hitch plates 512L and 512R, the positions of the plurality of hitch adjustment holes 515 in the front-rear and vertical directions are the same. That is, when the left and right front vertical hitch plates 512L and 512R are stacked in the left-right direction, the hitch adjustment holes 515 on each side overlap in the left-right direction.

[0037] Each of the pair of rear side plates 513U and 513L of the hitch section has a connecting pin hole 516 that penetrates vertically. The connecting pin holes 516 provided in each rear side plate 513U and 513L of the hitch section are the same shape and size. The connecting pin holes 516 are circular in shape when viewed from above. The positions of the connecting pin holes 516 in the front-rear and left-right directions are the same between the upper and lower rear side plates 513U and 513L of the hitch section. That is, when the upper and lower rear side plates 513U and 513L of the hitch section are stacked vertically, the upper and lower connecting pin holes 516 overlap vertically. In detail, the connecting pin holes 516 are provided in the center of the hitch section 51 in the left-right direction.

[0038] The support portion 52 is a single component formed by processing and welding a metal member such as sheet metal. The formation method and shape of the support portion 52 may be changed as appropriate. The support portion 52 may also be configured by connecting multiple members using fasteners such as screws. As shown in Figures 4 and 5, the support portion 52 has a rectangular flat support base plate 521 that extends in the front-to-back and left-to-right directions. The support portion 52 has a pair of flat support vertical plates 522L and 522R positioned on the left and right sides of the support base plate 521 and extending vertically. The pair of support vertical plates 522L and 522R are identical in shape.

[0039] Furthermore, the majority of the pair of support vertical plates 522L and 522R are located above the support base plate 521. In addition, the support 52 includes a flat support reinforcing plate 523 located inward in the left-right direction of the pair of support vertical plates 522L and 522R, but this reinforcing plate 523 may or may not be present.

[0040] The support base plate 521 is provided with at least one bolt hole BH that penetrates vertically and through which a bolt BT is passed.

[0041] Each of the pair of vertical support plates 522L and 522R has a plurality of support adjustment holes 525 that penetrate in the left-right direction. The plurality of support adjustment holes 525 are the same shape and size. The support adjustment holes 525 are circular in shape when viewed from the left-right direction. In each of the pair of vertical support plates 522L and 522R, the plurality of support adjustment holes 525 are arranged at equal intervals in the vertical direction and are located at the rear of the plate. Between the left and right vertical support plates 522L and 522R, the positions of the plurality of adjustment holes 525 in the front-rear and vertical directions are the same. That is, when the left and right vertical support plates 522L and 522R are stacked in the left-right direction, the respective support adjustment holes 525 on the left and right overlap in the left-right direction.

[0042] Furthermore, each of the pair of support vertical plates 522L and 522R is provided with at least one bolt hole BH at its front, which penetrates in the left-right direction and through which a bolt BT is passed. Also, each of the left and right support vertical plates 522L and 522R is provided with at least one bolt notch BN that is recessed from the front end toward the rear and through which a bolt BT is passed. Note that it is not necessary to provide both the bolt hole BH and the bolt notch BN; a configuration in which only one of them is provided is also possible.

[0043] As shown in Figure 3, the support portion 52 is attached to the transmission case 9. Specifically, the support portion base plate 521 is attached to the lower surface of the transmission case 9 by bolts BT. In addition, the left and right support portion vertical plates 522L and 522R are attached to the left and right surfaces of the transmission case 9 by bolts BT.

[0044] As shown in Figures 3 and 4, the hitch section 51 is connected to the support section 52 using first connecting pins 55. In this embodiment, there are multiple (specifically two) first connecting pins 55. Specifically, first, on both the left and right sides, the hitch section adjustment holes 515 provided in the front vertical plates 512L and 512R of the hitch section and the support section adjustment holes 525 provided in the vertical plates 522L and 522R of the support section are overlapped in the left-right direction. Then, the first connecting pins 55 are inserted into the adjustment holes 515 and 525 that are overlapped in the left-right direction. This connects the hitch section 51 to the support section 52. The first connecting pins 55 are provided with retaining clips, and the hitch section 51 and the support section 52 can be fixed by inserting the pins into the adjustment holes. Instead of pins, the hitch section 51 and the support section 52 may be fixed with other fasteners such as bolts.

[0045] In this embodiment, the number of hitch adjustment holes 515 provided in each of the left and right front vertical plates 512L and 512R of the hitch section, and the number of support adjustment holes 525 provided in each of the left and right vertical plates 522L and 522R of the support section, are both multiple. Therefore, the height of the hitch section 51 can be adjusted by selecting how to combine the hitch adjustment holes 515 and support adjustment holes 525 that are arranged in the vertical direction. In other words, the work vehicle 1 is provided with a height adjustment mechanism 57 that allows the support height of the hitch section 51 by the support section 52 to be adjusted. Because the support height of the hitch section 51 can be changed, it is possible to accommodate differences in towing height due to differences in the type and size of the towed object 100.

[0046] In this embodiment, as shown in Figure 3, the height adjustment mechanism 57 is located in front of the rear end of the PTO shaft 11. That is, the support portion 52 supports the hitch portion 51 in front of the rear end of the PTO shaft 11. This makes it possible to shorten the distance L between the rear axle 10 and the load position when the towed body 100 is connected. For this reason, the weights placed on the work vehicle 1 to ensure front-to-rear balance can be eliminated or reduced. In this embodiment, the support portion 52 supports the hitch portion 51 in front of the rear end 25a of the draft mechanism 25.

[0047] In this embodiment, the number of hitch adjustment holes 515 provided on both the left and right sides of the hitch portion 51, and the number of support adjustment holes 525 provided on both the left and right sides of the support portion 52, are both set to multiple. However, this is merely an example. For example, either the number of hitch adjustment holes 515 provided on both the left and right sides of the hitch portion 51, or the number of support adjustment holes 525 provided on both the left and right sides of the support portion 52, may be set to one. Even in this case, the height of the hitch portion 51 can be adjusted. In other words, the work vehicle 1 can be configured to include a height adjustment mechanism.

[0048] Furthermore, the number of hitch adjustment holes 515 provided on each side of the hitch section 51 and the number of support adjustment holes 525 provided on each side of the support section 52 may both be a single number. In this case, the work vehicle 1 will not be equipped with a height adjustment mechanism. However, even in this case, the support section 52 is configured to support the hitch section 51 in front of the rear end 11a of the PTO shaft 11, so the distance L (see Figure 3) between the rear axle 10 and the load position can be shortened. As a result, it is easier to accommodate heavier towed objects 100, and the variety of towable objects can be increased as much as possible.

[0049] When the towed body 100 is towed by the hitch section 51, the second connecting pin 56 is inserted into the connecting pin hole 516. At this time, the second connecting pin 56 is also passed through a through hole (not shown) provided in the towing member 53, whose front end is positioned between the upper and lower rear lateral plates 513U and 513L of the hitch section. As a result, the towed body 100 is connected to the hitch section 51 via the towing member 53. The towing section 50A of this embodiment is suitable for a configuration in which the towed body 100 is towed below the PTO shaft 11. The towed body 100 in such a configuration may include, for example, a trailer.

[0050] [2-2. Second Example] Figure 6 is a side view showing the general configuration of the towing unit 50B and its surrounding area in the second embodiment. Figure 6 also shows the towed body 100 located at the rear of the vehicle body 2. As shown in Figure 6, the towing unit 50B includes a hitch unit 61 and a support unit 62. The functions of the hitch unit 61 and support unit 62 in this embodiment overlap considerably with the functions of the hitch unit 51 and support unit 52 in the first embodiment. Explanations of overlapping content will be omitted as appropriate.

[0051] The hitch section 61 is connected to the towed object 100 via the towing member 63. In the example shown in Figure 6, the towed object 100 is a work machine. The towed object 100, towed by the work vehicle 1 via the towing member 63, receives power from the PTO shaft 11 via the drive shaft 64 and performs operations for work. In this example as well, as in the first embodiment, the work vehicle 1 may tow a towed object 100 that does not require power transmission from the PTO shaft 11.

[0052] The support portion 62 is attached to the transmission case 9 and supports the hitch portion 61. In this embodiment, the rear end 62a of the support portion 62 is located behind the rear end 11a of the PTO shaft 11. Furthermore, the rear end 62a of the support portion 62 is located behind the rear end of the top link mounting portion 21 (i.e., the rear end 25a of the draft mechanism 25). With this configuration, the hitch portion 61 can be attached to the support portion 62 while avoiding contact with the draft mechanism 25 at the height position where the draft mechanism 25 is installed.

[0053] Figure 7 is an exploded perspective view showing the schematic configuration of the towing section 50B of the second embodiment. Note that the first connecting pin 65 (see Figure 6) for connecting the hitch section 61 and the support section 62 is omitted in Figure 7. Also, the second connecting pin 66 (see Figure 6) for connecting the hitch section 61 and the towing member 63 is omitted in Figure 7.

[0054] The hitch portion 61 is a single component formed by processing and welding a metal member such as sheet metal. The method of forming the hitch portion 61 and its shape may be modified as appropriate. The support portion 62 may be a configuration in which multiple members are connected using fasteners such as screws. As shown in Figure 7, the hitch portion 61 has a rectangular flat hitch portion base plate 611 that extends in the vertical and horizontal directions. The left and right sides of the hitch portion base plate 611 are provided with hitch portion adjustment holes 612 that extend in the horizontal direction.

[0055] Furthermore, the hitch section 61 has a pair of flat hitch section rear lateral plates 613U and 613L that extend rearward from the upper and lower ends of the rear surface of the hitch section base plate 611. The pair of hitch section rear lateral plates 613U and 613L are spaced apart vertically. The pair of hitch section rear lateral plates 613U and 613L are identical in shape. The pair of hitch section rear lateral plates 613U and 613L extend in the front-to-back and left-to-right directions.

[0056] Each of the pair of rear lateral hitch plates 613U and 613L has a connecting pin hole 614 that penetrates vertically. The connecting pin holes 614 in each rear lateral hitch plate 613U and 613L are the same shape and size. The connecting pin holes 614 are circular in a plan view from the top and bottom. The positions of the connecting pin holes 614 in the front-rear and left-right directions are the same between the upper and lower rear lateral hitch plates 613U and 613L. That is, when the upper and lower rear lateral hitch plates 613U and 613L are stacked vertically, the upper and lower connecting pin holes 614 overlap vertically. In detail, the connecting pin holes 614 are located in the center of the hitch portion 61 in the left-right direction.

[0057] Furthermore, the hitch section 61 has a pair of flat hitch section reinforcing plates 615L and 615R on the rear side of the hitch section base plate 611, connecting the left ends and right ends of the pair of hitch section rear lateral plates 613U and 613L, respectively. The pair of hitch section reinforcing plates 615L and 615R are identical in shape. The pair of hitch section reinforcing plates 615L and 615R extend in the front-to-back and up-to-down directions.

[0058] The support portion 62 is a single component formed by processing and welding a metal member such as sheet metal. The method of forming the support portion 62 and its shape may be changed as appropriate. The support portion 62 may also be configured by connecting multiple members using fasteners such as screws.

[0059] As shown in Figure 7, the support portion 62 has a rectangular flat plate lower support portion base plate 621 that extends in the front-rear and left-right directions. The support portion 62 also has a rectangular flat plate upper support portion base plate 622 above the lower support portion base plate 621 that extends in the front-rear and left-right directions.

[0060] Furthermore, the support section 62 has a pair of vertically extending plate-shaped support section vertical plates 623L and 623R positioned to the left and right of two base plates 621 and 622 that are spaced apart vertically, and extending vertically. The pair of support section vertical plates 623L and 623R connect the two base plates 621 and 622. The pair of support section vertical plates 623L and 623R are identical in shape. The pair of support section vertical plates 623L and 623R protrude downward from the lower support section base plate 621. Also, the pair of support section vertical plates 623L and 623R protrude upward from the upper support section base plate 622.

[0061] Furthermore, the support section 62 has a pair of left and right support columns 624L and 624R positioned at the rear ends of the pair of vertical support plates 623L and 623R. Each of the left and right support columns 624L and 624R extends in the vertical direction and is positioned over the range from the lower end to the upper end of the left and right vertical support plates 623L and 623R. Each of the pair of support columns 624L and 624R is provided with a groove 628 on its inward surface in the left-right direction, which is recessed outward in the left-right direction. The grooves 628 provided on each of the left and right support columns 624L and 624R extend from the lower end to the upper end of the support column.

[0062] The lower base plate 621 of the support section is provided with at least one bolt hole BH that penetrates vertically and through which a bolt BT is passed. Furthermore, the upper surface of the upper base plate 622 of the support section is provided with a flat support section fixing plate 626 that extends parallel to the left-right and up-down directions. In detail, the support section fixing plate 626 is divided into two parts spaced apart from each other. The front surface of each of the left and right divided parts of the support section fixing plate 626 is provided with a cylindrical portion 627 extending forward. A bolt BT is passed through the pair of left and right cylindrical portions 627.

[0063] Each of the left and right support vertical plates 623L and 623R is provided with at least one bolt hole BH at its front, which penetrates in the left-right direction and through which a bolt BT is passed. Furthermore, each of the left and right support vertical plates 623L and 623R is provided with at least one bolt notch BN recessed from the front end towards the rear, through which a bolt BT is passed. Note that both the bolt hole BH and the bolt notch BN are not required; a configuration with only one of them is also acceptable.

[0064] Each of the left and right support columns 624L and 624R has a plurality of support adjustment holes 625 that penetrate in the left-right direction. The plurality of support adjustment holes 625 are the same shape and size. The support adjustment holes 625 are circular in a plan view from the left-right direction. In each of the left and right support columns 624L and 624R, the plurality of support adjustment holes 625 are arranged at equal intervals in the vertical direction. The positions of the plurality of adjustment holes 625 in the front-rear and vertical directions are the same between the left and right support columns 624L and 624R. The support adjustment holes 625 are provided on the bottom surface of the groove 628.

[0065] As shown in Figure 6, the support portion 62 is attached to the components constituting the transmission case 9 and the draft mechanism 25. Specifically, the lower base plate 621 of the support portion is attached to the lower surface of the transmission case 9 by bolts BT. The left and right vertical support plates 623L and 623R are attached to the left and right surfaces of the transmission case 9 by bolts BT. Bolts BT that pass through a pair of cylindrical portions 627 provided on the support portion fixing plate 626 are attached to a bracket 26, which is a component of the draft mechanism 25. The bracket 26 is a component that pivotably supports the top link mounting portion 21.

[0066] As shown in Figure 6, the hitch section 61 is connected to the support section 62 using a first connecting pin 65. In detail, first, the left and right ends of the hitch section base plate 611 are fitted into grooves 628 provided in the left and right support columns 624L and 624R. Then, on both the left and right sides, the hitch section adjustment holes 612 provided in the hitch section base plate 611 and the support section adjustment holes 625 provided in the support columns 624L and 624R are overlapped in the left-right direction. In this state, the first connecting pin 65 is inserted into the adjustment holes 612 and 625 that are overlapped in the left-right direction. This connects the hitch section 61 to the support section 62. The first connecting pin 65 is provided with a retaining mechanism, and the hitch section 61 and the support section 62 can be fixed by inserting the pin into the adjustment hole. Instead of the pin, the hitch section 61 and the support section 62 may be fixed with other fasteners such as bolts.

[0067] In this embodiment, there is only one hitch adjustment hole 612 on the left and right sides of the hitch section 61. On the other hand, there are multiple support adjustment holes 625 on each of the left and right support columns 624L and 624R. Therefore, the height of the hitch section 61 can be adjusted by selecting the support adjustment holes 625 to be combined with the hitch adjustment holes 612. In other words, the work vehicle 1 is provided with a height adjustment mechanism 67 that allows adjustment of the support height of the hitch section 61 by the support section 62. Because the support height of the hitch section 61 can be changed, it is possible to accommodate differences in towing height due to differences in the type and size of the towed object 100.

[0068] In this embodiment, as shown in Figure 6, the height adjustment mechanism 67 is located behind the rear end 25a of the draft mechanism 25. That is, the support portion 62 supports the hitch portion 61 behind the draft mechanism 25. This allows the hitch portion 61 to be positioned at a higher location while avoiding contact with the draft mechanism 25, which is located at the upper rear of the work vehicle 1. In other words, the range of adjustable height for the hitch portion 61 can be widened. As a result, it is possible to easily accommodate differences in towing height due to differences in the type and size of the towed object 100.

[0069] In this embodiment, the number of hitch adjustment holes 612 provided on each side of the hitch portion 61 is set to one, and the number of support adjustment holes 625 provided on each side of the support portion 62 is set to multiple. However, this is merely an example. For example, the number of hitch adjustment holes 612 provided on each side of the hitch portion 61 and the number of support adjustment holes 625 provided on each side of the support portion 62 may both be set to multiple. Alternatively, the number of hitch adjustment holes 612 provided on each side of the hitch portion 61 may be set to multiple, and the number of support adjustment holes 625 provided on each side of the support portion 62 may be set to one. Even in these cases, the height of the hitch portion 61 can be adjusted. In other words, the work vehicle 1 can be configured to have a height adjustment mechanism.

[0070] Furthermore, the number of hitch adjustment holes 612 provided on each side of the hitch portion 61 and the number of support adjustment holes 625 provided on each side of the support portion 62 may both be set to a single number. In this case, a height adjustment mechanism will not be provided. However, even in this case, the support portion 62 will support the hitch portion 61 behind the rear end 25a of the draft mechanism 25, so it can accommodate towed objects 100 with a high towing height.

[0071] When the towed body 100 is towed by the hitch portion 61, the second connecting pin 66 is inserted into the connecting pin hole 614. At this time, the second connecting pin 66 is also passed through a through hole (not shown) provided in the towing member 63, whose front end is positioned between the upper and lower rear lateral plates 613U and 613L of the hitch portion. As a result, the towed body 100 is connected to the hitch portion 51 via the towing member 63. The towing portion 50B of this embodiment can be applied to a configuration in which the towed body 100 is towed above the PTO shaft 11, as shown in Figure 6. The towed body 100 in such a configuration may include, for example, a thresher.

[0072] [2-3. Third Example] Figure 8 is a side view showing the general configuration of the towing unit 50C and its surrounding area in the third embodiment. Figure 8 also shows the towed body 100 located at the rear of the vehicle body 2. As shown in Figure 8, the towing unit 50C comprises a hitch unit 71 and a support unit 72. The functions of the hitch unit 71 and support unit 72 in this embodiment overlap considerably with the functions of the hitch units 51, 61 and support units 62, 72 in the first and second embodiments. Explanations of overlapping content will be omitted as appropriate.

[0073] The hitch section 71 is connected to the towed body 100 via the towing member 73. In the example shown in Figure 8, the towed body 100 does not require power transmission. However, even in this embodiment, the towed body 100 may be configured to require power transmission. In this case, as shown in Figure 11, which will be described later, power may be transmitted from the PTO shaft 11 via the drive shaft 74.

[0074] The support portion 72 is attached to at least the transmission case 9 and supports the hitch portion 71. In this embodiment, the support portion 72 includes a first support portion 721 and a second support portion 722. The first support portion 721 and the second support portion 722 may be configured as a single member. However, in this embodiment, the first support portion 721 and the second support portion 722 are configured as separate members. The second support portion 722 is positioned above the first support portion 721.

[0075] The first support portion 721 is attached to the transmission case 9. That is, the first support portion 721 is fixed to the vehicle body 2. The second support portion 722 is fixed to the first support portion 721. With this configuration, the second support portion 722 can be positioned as needed. That is, the second support portion 722 can be removed when not needed.

[0076] In this embodiment, the second support portion 722 is fixed to a component of the draft mechanism 25. The component of the draft mechanism 25 may be, for example, a bracket 26 fixed to the case of the lifting unit 16 described above. With this configuration, the support rigidity of the support portion 72 can be increased.

[0077] In this embodiment, the rear end 721a of the first support portion 721 is located in front of the rear end 11a of the PTO shaft 11. Also, the rear end 722a of the second support portion 722 is located behind the rear end of the top link mounting portion 21 (i.e., the rear end 25a of the draft mechanism 25).

[0078] Figure 9 is a schematic perspective view showing the hitch portion 71 and support portion 72, which constitute the towing portion 50C of the third embodiment, in an exploded view. Note that the first connecting pin 75 (see Figure 8) for connecting the hitch portion 71 and the support portion 72 is omitted in Figure 9. Also, the second connecting pin 76 (see Figure 8) for connecting the hitch portion 71 and the towing member 73 is omitted in Figure 9. Figure 10 is a schematic perspective view showing the first support portion 721 and the second support portion 722, which constitute the support portion 72 of the third embodiment, in an exploded view.

[0079] The configuration of the hitch section 71 in the third embodiment is the same as that of the hitch section 51 in the first embodiment. For this reason, a detailed explanation will be omitted. The hitch section 71 includes a hitch section base plate 711, a pair of left and right front vertical plates 712L and 712R for the hitch section, a pair of upper and lower rear horizontal plates 713U and 713L for the hitch section, and a pair of left and right reinforcement plates 714L and 714R for the hitch section. Each of the pair of front vertical plates for the hitch section has a plurality of hitch section adjustment holes 715. Each of the pair of rear horizontal plates for the hitch section 713U and 713L has a connecting pin hole 716.

[0080] The first support portion 721 and the second support portion 722 are each constructed, for example, by processing and welding a metal member such as sheet metal. The formation method and shape of the first support portion 721 and the second support portion 722 may be changed as appropriate.

[0081] The configuration of the first support portion 721 is generally the same as that of the support portion 52 in the first embodiment. For this reason, a detailed explanation will be omitted. The first support portion 721 has a first support portion base plate 7211 and a pair of left and right first support portion vertical plates 7212L and 7212R. The first support portion base plate 7211 has bolt holes BH. Each of the pair of first support portion vertical plates 7212L and 7212R has a plurality of support portion adjustment holes 725. Each of the left and right first support portion vertical plates 7212L and 7212R has bolt holes BH and bolt notches BN. The bolt holes BH provided in each of the left and right first support portion vertical plates 7212L and 7212R include bolt holes BH for connecting the second support portion 722. This point differs from the support portion 52 in the first embodiment. The bolt holes BH for connecting to the second support portion 722 are provided above the center portion in the front-to-back direction of the first support portion vertical plates 7212L and 7212R.

[0082] The second support section 722 has a rectangular flat second support section base plate 7221 that extends in the left-right and up-down directions. The second support section 722 has a pair of flat second support section vertical plates 7222L and 7222R positioned to the left and right of the second support section base plate 7221 and extending in the front-back and up-down directions. The pair of second support section vertical plates 7222L and 7222R are identical in shape. The second support section 722 includes a flat second support section reinforcing plate 7223 (see Figure 10), but this reinforcing plate 7223 may or may not be present.

[0083] The second support base plate 7221 has cylindrical portions 7224 extending forward on the left and right sides of its front surface. Bolts BT for attachment to the bracket 26 are passed through the pair of left and right cylindrical portions 7224.

[0084] Each of the left and right second support vertical plates 7222L and 7222R has a plurality of support adjustment holes 725 that penetrate in the left-right direction. The plurality of support adjustment holes 725 are the same shape and size. The plurality of support adjustment holes 725 provided in the second support 722 are the same shape and size as the plurality of support adjustment holes 725 provided in the first support 721. The support adjustment holes 725 are circular in shape when viewed from the left-right direction in plan view.

[0085] In each of the left and right second support vertical plates 7222L and 7222R, the multiple support adjustment holes 725 are arranged at equal intervals in the vertical direction and are located at the rear of the plate. The positions of the multiple adjustment holes 725 in the front-to-back and vertical directions are the same between the left and right second support vertical plates 7222L and 7222R. That is, when the left and right second support vertical plates 7222L and 7222R are stacked in the left-to-right direction, the support adjustment holes 725 on each side overlap in the left-to-right direction. Each of the left and right second support vertical plates 7222L and 7222R is provided with at least one bolt hole BH at the front, which penetrates in the left-to-right direction and through which a bolt BT is passed. The bolt hole BH is provided for connection with the first support 721.

[0086] As shown in Figures 8 and 9, the first support portion 721 and the second support portion 722 are connected using bolts BT, and a support portion 72 is obtained in which the first support portion 721 and the second support portion 722 are integrated. The first support portion base plate 7211 is attached to the lower surface of the transmission case 9 with bolts BT. In addition, the left and right first support portion vertical plates 7212L and 7212R are attached to the left and right surfaces of the transmission case 9 with bolts BT. The second support portion 722 is fixed to the bracket 26 by bolts BT passed through the cylindrical portion 7224.

[0087] In this embodiment, when the support portion 72 is configured such that its bottom, left and right sides, and front are attached to the components constituting the vehicle body 2, if the support portion 72 is a single component, a high level of precision is required in the manufacturing of the component. In this embodiment, however, the support portion 72 is divided into a first support portion 721 and a second support portion 722, which are separate components. This reduces the required precision in the manufacturing of the component. In other words, the configuration of this embodiment makes component management easier.

[0088] As shown in Figure 8, the hitch section 71 is connected to the support section 72 using a first connecting pin 75. In this embodiment, there are multiple first connecting pins 75 (specifically two). Specifically, on both the left and right sides, the hitch section adjustment holes 715 provided in the front vertical plates 712L and 712R of the hitch section and the support section adjustment holes 725 provided in the first vertical plates 7212L and 7212R or the second vertical plates 7222L and 7222R of the support section are overlapped in the left-right direction. Then, the first connecting pins 75 are inserted into the adjustment holes 715 and 725 that are overlapped in the left-right direction. This connects the hitch section 71 to the support section 72. The first connecting pins 75 are provided with retaining clips, and the hitch section 71 and the support section 72 can be fixed by inserting the pins into the adjustment holes. Instead of using a pin, the hitch portion 71 and the support portion 72 may be fixed together using other fasteners such as bolts.

[0089] In this embodiment, on both the left and right sides, there are multiple hitch adjustment holes 715 provided in the front vertical plates 712L and 712R of the hitch section, and multiple support adjustment holes 725 provided in the first vertical plates 7212L and 7212R and the second vertical plates 7222L and 7222R of the support section. Therefore, the height of the hitch section 71 can be adjusted by selecting the combination of hitch adjustment holes 715 and support adjustment holes 725. In other words, the work vehicle 1 is provided with a height adjustment mechanism 77 that allows adjustment of the support height of the hitch section 71 by the support section 72. Because the support height of the hitch section 71 can be changed, it is possible to accommodate differences in towing height due to differences in the type and size of the towed object 100.

[0090] In this embodiment, multiple support adjustment holes 725 are provided in both the first support vertical plates 7212L and 7212R and the second support vertical plates 7222L and 7222R. For this reason, a first height adjustment mechanism 771 is provided that allows adjustment of the support height of the hitch portion 71 by the first support portion 721, and a second height adjustment mechanism 772 is provided that allows adjustment of the support height of the hitch portion 71 by the second support portion 722.

[0091] The height adjustment mechanism 77 may include at least one of the first height adjustment mechanism 771 and the second height adjustment mechanism 772. Alternatively, the first support portion 721 and the second support portion 722 may not each have a height adjustment mechanism. Even in this case, if the hitch portion 71 can be connected to both the first support portion 721 and the second support portion 722, the support height of the hitch portion 71 by the support portion 72 can be adjusted.

[0092] More specifically, as shown in Figure 8, the first height adjustment mechanism 771 provided on the first support portion 721 is located in front of the rear end of the PTO shaft 11. That is, the first support portion 721 supports the hitch portion 71 in front of the PTO shaft 11. Furthermore, the second height adjustment mechanism 772 provided on the second support portion 722 is located above the first support portion 721 and behind the rear end 25a of the draft mechanism 25. That is, the second support portion 722 supports the hitch portion 71 above the first support portion 721 and behind the draft mechanism 25.

[0093] With this configuration, the first support portion 721 can tow a towed object 100 at a low towing height. The second support portion 722 can then tow a towed object 100 at a higher towing height. In other words, with the configuration of this embodiment, the height adjustable range of the hitch portion 71 can be widened. As a result, it is possible to easily accommodate differences in towing height due to differences in the type and size of the towed object 100.

[0094] Furthermore, in the configuration of this embodiment, the hitch section 71 can be positioned as far forward as possible by utilizing the first support section 721, even with respect to the towed body 100, which tends to become heavy due to the load such as a trailer. In this case, the distance L (see Figure 8) between the rear axle 10 and the load position can be shortened. As a result, even with the towed body 100, which tends to become heavy, towing can be performed without any extra measures such as increasing the weight of the work vehicle 1.

[0095] Figure 11 illustrates a case where the towed body 100 is towed at a different towing height than in Figure 8. In the example shown in Figure 8, the hitch portion 71 is connected to the first support portion 721. This configuration is suitable for towed bodies where the height at which the towed body 100 is towed by the towing member 73 is below the PTO shaft 11. In the example shown in Figure 11, the hitch portion 71 is connected to the second support portion 722. This configuration is suitable for towed bodies where the height at which the towed body 100 is towed by the towing member 73 is above the PTO shaft 11.

[0096] <3. Things to keep in mind> Various technical features disclosed herein can be modified in various ways without departing from the spirit of the technical creation. Furthermore, the multiple embodiments and modifications shown herein may be combined as possible. [Explanation of symbols]

[0097] 1. Work vehicles 2. Vehicle body 11. PTO shaft 16. Lifting Unit 25. Draft mechanism 26. Bracket (a component that makes up the draft mechanism) 51, 61, 71...Hitch section 52, 62, 72...Support part 57, 67, 77... Height adjustment mechanism 100...Towed object 721...1st support part 721...Second support part 771...First height adjustment mechanism 772...Second height adjustment mechanism

Claims

1. A work vehicle equipped to tow a towed object located at the rear of the vehicle body, The hitch portion connected to the towed body, A support portion attached to the vehicle body and supporting the hitch portion, A lifting unit mounted on the vehicle body, A draft mechanism for adjusting the towing load for towing a work device positioned at the rear of the vehicle body so as to be able to move up and down by the aforementioned lifting unit, Equipped with, A height adjustment mechanism is provided that allows the support height of the hitch portion by the support portion to be adjusted. The support portion is a work vehicle that supports the hitch portion behind the draft mechanism.

2. The vehicle body is equipped with a PTO shaft that can transmit power from the engine mounted on the vehicle body to the outside of the vehicle body, The work vehicle according to claim 1, wherein the support portion supports the hitch portion in front of the rear end of the PTO shaft.

3. A work vehicle equipped to tow a towed body located at the rear of the vehicle body, The hitch portion connected to the towed body, A support portion attached to the vehicle body and supporting the hitch portion, A PTO shaft that enables power from the engine mounted on the vehicle body to be transmitted to the outside of the vehicle body, A lifting unit mounted on the vehicle body, A draft mechanism for adjusting the towing load for towing a work device positioned at the rear of the vehicle body so as to be able to move up and down by the aforementioned lifting unit, Equipped with, A height adjustment mechanism is provided that allows the support height of the hitch portion by the support portion to be adjusted. The aforementioned support portion is A first support portion that supports the hitch portion in front of the rear end of the PTO shaft, A second support portion that supports the hitch portion above the first support portion and behind the draft mechanism, Work vehicles, including those mentioned above.

4. The aforementioned height adjustment mechanism is A first height adjustment mechanism that allows the support height of the hitch portion by the first support portion to be adjusted, A second height adjustment mechanism that allows the support height of the hitch portion by the second support portion to be adjusted, A work vehicle according to claim 3, comprising at least one of the above.

5. The first support portion and the second support portion are composed of separate members. The first support portion is fixed to the vehicle body, The work vehicle according to claim 3 or 4, wherein the second support portion is fixed to the first support portion.

6. The work vehicle according to claim 5, wherein the second support portion is fixed to a member constituting the draft mechanism.

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