JP2024004953A - work vehicle - Google Patents

Abstract

An object of the present invention is to provide a technology that can increase the number of types of towed objects that can be towed by a work vehicle. An exemplary work vehicle is a work vehicle that is installed to be capable of towing a towed object disposed at the rear of a vehicle body, and includes a hitch portion connected to the towed object and a hitch portion attached to the vehicle body. , a support part that supports the hitch part. A height adjustment mechanism is provided that allows adjustment of the height at which the hitch part is supported by the support part. [Selection diagram] Figure 3

Description

The present invention relates to a work vehicle.

2. Description of the Related Art Conventionally, a working vehicle is known in which a working device is connectable to the rear part using a traction member (see, for example, Patent Document 1). One end side of the towing member is connected to a towing hitch provided at the rear of the work vehicle. The other end of the traction member is connected to a working device.

Patent No. 6949772

By the way, there are various types of objects towed by work vehicles. Furthermore, the size of the towed object also varies. The height position at which the traction member is attached may vary depending on the type and size of the towed object. It is undesirable that the types of towed objects that can be towed by a work vehicle decrease due to differences in the height positions at which the towing members are attached.

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

An exemplary work vehicle of the present invention is a work vehicle that is installed to be capable of towing a towed object disposed at the rear of a vehicle body, and includes a hitch portion connected to the towed object, and a hitch portion attached to the vehicle body; A support part that supports the hitch part. A height adjustment mechanism is provided that allows adjustment of the height at which the hitch part is supported by the support part.

According to the exemplary embodiment of the present invention, it is possible to increase the types of towed objects that can be towed as much as possible.

Side view showing the general configuration of the work vehicle A perspective view showing a schematic configuration of a mission case included in a work vehicle and its surroundings. A side view showing the general configuration of the traction part and its surroundings in the first embodiment A perspective view showing the general configuration of the traction part of the first embodiment An exploded perspective view showing the general configuration of the traction section of the first embodiment A side view showing the general configuration of the traction part and its surroundings in the second embodiment Exploded perspective view showing the general configuration of the traction part of the second embodiment A side view showing the general configuration of the traction part and its surroundings in the third embodiment A schematic perspective view showing a hitch part and a support part disassembled that constitute a traction part of the third embodiment A schematic perspective view showing an exploded first support part and a second support part constituting the support part of the third embodiment A diagram illustrating a case where a towed object is towed at a towing height different from that in FIG. 8.

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

Note that in this specification, a direction is defined as follows. First, the direction in which the work vehicle travels during work is defined as "front", and the opposite direction is defined as "rear". In addition, the right side in the direction of movement of the work vehicle during work is defined as the right, and the left side is defined as the left. Further, a direction perpendicular to the front-back direction and the left-right direction of the work vehicle is defined as the up-down direction. At this time, the direction of gravity is set as the bottom, and the opposite side is set as the top. The above directions are simply names used for explanation and are not intended to limit the actual positional relationships and directions.

<1. Overview of work vehicle＞
FIG. 1 is a side view showing a schematic configuration of a work vehicle 1 according to an embodiment of the present invention. Note that FIG. 1 shows the left side of the work vehicle 1. The work vehicle 1 is provided so as to be able to tow a towed object 100 (see FIG. 3, etc.) disposed behind the vehicle body 2. The work vehicle 1 is provided to be able to carry out work such as agricultural work while towing the towed object 100. The towed object 100 may be, for example, a trailer or a working machine. The working machine may be an agricultural machine, a construction machine, or the like. In this embodiment, the work vehicle 1 is a tractor for agricultural work.

A pair of left and right front wheels 3 are arranged at the front of the vehicle body 2. A pair of left and right rear wheels 4 are arranged at the rear of the vehicle body 2. The vehicle body 2 can run using front wheels 3 and rear wheels 4. That is, 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 be a crawler tractor equipped with a crawler or the like.

An engine 6 covered by a bonnet 5 is disposed at the front of the vehicle body 2. The engine 6 is a driving 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 drive source of the work vehicle 1 may be another drive source such as an electric motor instead of the engine. Further, a front axle case (not shown) including a front axle 7 that supports a pair of left and right front wheels 3 is arranged below the engine 6 at the front of the vehicle body 2 .

A clutch housing 8 including a clutch (not shown) is connected to the rear of the engine 6. A transmission case 9 is arranged behind the clutch housing 8. A power transmission device (not shown) is arranged inside the mission case 9. The rotational power of the engine 6 is transmitted to at least one of the front wheels 3 and the rear wheels 4 via a power transmission device within 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 on both left and right side surfaces of the transmission case 9.

A PTO shaft 11 that can transmit power from the engine 6 to the outside of the vehicle body 2 is provided on the rear surface of the mission case 9 . That is, the work vehicle 1 includes a PTO shaft 11 that allows power from an engine 6 mounted on the vehicle body 2 to be transmitted to the outside of the vehicle body 2 . Specifically, the PTO shaft 11 protrudes rearward from the rear surface of the mission case 9. The towed object 100 disposed at the rear of the vehicle body 2 may be configured to receive power transmission from the PTO shaft 11 .

An operating section 12 is provided above the clutch housing 8 and the transmission case 9 of the vehicle body 2 . The driving section 12 is a section on which a driver (operator) rides. The driving section 12 includes a driver's seat 13 on which a driver sits, and a steering wheel 14 arranged in front of the driver's seat 13. Further, the driver section 12 has a rope 15 at the rear of the driver's seat 13. By providing the ropes 15, the driver can be protected when the work vehicle 1 falls over. The driving unit 12 also includes an operating lever, a pedal, and the like.

In this embodiment, an elevating unit 16 is arranged on the upper surface of the rear part of the mission case 9. That is, the work vehicle 1 includes a lifting unit 16 mounted on the vehicle body 2. The elevating unit 16 allows a working device (not shown) disposed at the rear of the vehicle body 2 to be raised and lowered. Note that the working device that can be raised and lowered by the lifting unit 16 is also towed by the working vehicle 1, so it can be said to be a towed object. However, as will be described in detail later, this working device differs in the method of towing from the towed object 100 shown in FIG. 3 and the like. For this reason, in this specification, a working device that can be raised and lowered by the lifting unit 16 is expressed as a working device rather than a towed object for convenience in order to distinguish it from the towed object 100 shown in FIG. 3 etc. do. The working device may be, for example, a plow, a rotary tiller, a disc harrow, a cultivator, or a subsoiler.

The working device is connected via a three-point link mechanism 17 provided at the rear of the mission case 9. The three-point link mechanism 17 includes a pair of left and right lower links 18 and a top link 19.

FIG. 2 is a perspective view showing the general configuration of the mission case 9 and its surroundings included in the work vehicle 1 according to the embodiment of the present invention. As shown in FIG. 2, the left lower link 18L has its front end rotatably connected to the rear portion of the left side surface of the transmission case 9 via a lower link pin 20. As shown in FIG. The right lower link 18R has its front end rotatably connected to the rear part of the right side surface of the transmission case 9 via a lower link pin 20. The front end of the top link 19 is connected to a top link attachment portion 21 provided on the rear surface of the elevating unit 16 via a top link pin (not shown). In addition, the top link attachment part 21 is provided so that the attachment height position of the top link 19 can be adjusted.

The elevating unit 16 has a hydraulic cylinder (not shown) disposed within a housing that constitutes the unit. As shown in FIGS. 1 and 2, the elevating unit 16 has a pair of left and right lift arms 22 rotatably provided by hydraulic cylinders. 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 (see FIG. 1, omitted in FIG. 2) arranged on the left side. The right lift arm 22R is connected to the right lower link 18R by a lift rod 23 arranged on the right side. The lift rod 23 is attachable to and detachable from the lift arm 22 and the lower link 18.

Note that the working device includes a connecting portion connected to the rear end portions of the left and right lower links 18 and a connecting portion connected to the rear end portions of the top link 19. The working device can be connected to the three-point link mechanism 17 using these connecting parts. Furthermore, the left and right lower links 18 are removable from the transmission case 9. Further, the top link 19 is removable from the top link attachment portion 21. That is, the left and right lower links 18 and the top link 19 can be attached to or removed from the vehicle body 2 as appropriate.

As the elevating unit 16 is driven, the left and right lift arms 22 are rotated. By rotating the left and right lift arms 22, the working device connected via the three-point link mechanism 17 can be moved up and down. The working device can be supported at any height.

In this embodiment, a torsion bar 24 is arranged below the top link attachment part 21. When a traction load generated by towing the working device acts on the top link attachment portion 21 via the top link 19, a torsion force is applied to the torsion bar 24 via the top link attachment portion 21. When this twisting force becomes larger than the restoring force of the torsion bar 24, the top link attachment portion 21 swings from the reference position.

The elevating unit 16, top link attachment portion 21, and torsion bar 24 used together with the three-point link mechanism 17 constitute a draft mechanism 25 that performs known draft control. That is, the work vehicle 1 includes the draft mechanism 25. The draft mechanism 25 adjusts the traction load for towing a working device arranged at the rear of the vehicle body 2 so as to be able to be raised and lowered by the lifting unit 16 . Specifically, the draft mechanism 25 raises and lowers the working device according to the traction load, and adjusts the traction load to a constant level. For example, the draft mechanism 25 raises and lowers the working device to achieve the traction load set by a draft control lever (not shown). By providing the draft mechanism 25, it is possible to carry out plowing work and the like by towing the working device with a predetermined traction load set by the draft control lever.

As shown in FIGS. 1 and 2, in addition to the three-point linkage mechanism 17 for towing the working device described above, the work vehicle 1 also includes a towing section 50 that enables towing without using the three-point linkage mechanism 17. Be prepared. Hereinafter, this traction part 50 will be explained in detail.

<2. Traction part＞
[2-1. First Example]
FIG. 3 is a side view showing the general configuration of the traction portion 50A and its surroundings in the first embodiment. FIG. 3 also shows a towed object 100 arranged at the rear of the vehicle body 2. As shown in FIG. Note that the traction section 50 shown in FIG. 2 is the same as the traction section 50A of the first embodiment shown in FIG. 3. As shown in FIG. 3, the towing section 50A includes a hitch section 51 and a support section 52. That is, the work vehicle 1 includes a hitch portion 51 and a support portion 52.

The hitch portion 51 is connected to the towed object 100. Specifically, the hitch portion 51 is connected to the towed object 100 via the towing member 53. The front end of the traction member 53 is attached to the hitch portion 51. The rear end of the towing member 53 is attached to the towed body 100. In the example shown in FIG. 3, the towed object 100 is a working machine. The towed object 100 that is towed by the work vehicle 1 by the traction 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, has its rear end connected to, for example, a gear case of the towed object 100 so as to be capable of transmitting power.

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

The support part 52 is attached to the vehicle body 2. Specifically, the support portion 52 is attached to the mission case 9. The support portion 52 supports the hitch portion 51. That is, the hitch part 51 is attached to the vehicle body 2 via the support part 52. In this embodiment, the rear end 52a of the support portion 52 is located further forward than the rear end 11a of the PTO shaft 11. With such a configuration, the hitch portion 51 supported by the support portion 52 can be placed as far forward as possible. Therefore, the distance L (see FIG. 3) between the rear axle 10 and the load position (the connection position between the hitch portion 51 and the traction member 53) can be shortened. As a result, the weights placed on the work vehicle 1 for adjusting the front and rear weight balance can be reduced or eliminated.

Note that the support portion 52 is located forward of the rear end of the top link attachment portion 21 constituting the draft mechanism 25 (the rear end 25a of the draft mechanism 25).

FIG. 4 is a perspective view showing a schematic configuration of the traction section 50A of the first embodiment. FIG. 5 is an exploded perspective view showing a schematic configuration of the traction section 50A of the first embodiment. Note that in FIG. 5, the first connecting pin 55 (see FIG. 4, etc.) for connecting the hitch portion 51 and the support portion 52 is omitted. Further, in FIG. 5, the second connecting pin 56 (see FIG. 4, etc.) that connects the hitch portion 51 and the traction member 53 is omitted.

The hitch portion 51 is, for example, a single member formed by processing and welding a metal member such as a sheet metal. Note that the formation method and shape of the hitch portion 51 may be changed as appropriate. The hitch portion 51 may have a configuration in which a plurality of members are connected using a connecting tool such as a screw. As shown in FIGS. 4 and 5, the hitch portion 51 has a rectangular flat hitch portion base plate 511 that extends in the vertical and horizontal directions.

The hitch section 51 also includes a pair of hitch section front vertical plates 512L and 512R that extend forward from the left and right ends of the front surface of the hitch section base plate 511. The pair of hitch section front vertical plates 512L, 512R are arranged with an interval in the left-right direction. The pair of hitch portion front vertical plates 512L and 512R have the same shape. The pair of hitch section front vertical plates 512L, 512R spreads in the front-rear and up-down directions.

The hitch portion 51 also includes a pair of hitch portion rear horizontal plates 513U and 513L that extend rearward from the upper and lower ends of the rear surface of the hitch portion base plate 511. The pair of hitch portion rear horizontal plates 513U and 513L are arranged with an interval in the vertical direction. A pair of hitch portion rear horizontal plates 513U and 513L have the same shape. The pair of hitch portion rear horizontal plates 513U and 513L extend in the front-rear and left-right directions.

Further, the hitch section 51 has a pair of flat hitch section reinforcing plates 514L and 514R behind the hitch section base plate 511, which connect the left ends and right ends of the pair of hitch section rear horizontal plates 513U and 513L, respectively. The pair of hitch portion reinforcing plates 514L and 514R have the same shape. The pair of hitch portion reinforcing plates 514L and 514R extend in the front-rear and up-down directions.

Each of the pair of hitch section front vertical plates 512L, 512R has a plurality of hitch section adjustment holes 515 penetrating in the left-right direction. The plurality of hitch adjustment holes 515 have the same shape and size. The hitch adjustment hole 515 has a circular shape when viewed in plan from the left and right directions. In each of the pair of hitch section front vertical plates 512L, 512R, a plurality of hitch section adjustment holes 515 are arranged at equal intervals in the vertical direction and arranged in front of the plate. Between the left and right hitch part front vertical plates 512L, 512R, the positions where the plurality of hitch part adjustment holes 515 are provided in the front-rear direction and the vertical direction are the same. That is, when the left and right hitch section front vertical plates 512L, 512R are stacked in the left and right direction, the left and right hitch section adjustment holes 515 overlap in the left and right direction.

Each of the pair of hitch portion rear horizontal plates 513U and 513L has a connecting pin hole 516 that penetrates in the vertical direction. The connecting pin holes 516 provided in each hitch portion rear horizontal plate 513U, 513L have the same shape and size. The connecting pin hole 516 has a circular shape when viewed from above and below. Between the upper and lower hitch portion rear horizontal plates 513U and 513L, the positions in the front-rear direction and left-right direction where the connecting pin hole 516 is provided are the same. That is, when the upper and lower hitch portion rear horizontal plates 513U and 513L are stacked in the vertical direction, the upper and lower connecting pin holes 516 overlap in the vertical direction. Specifically, the connecting pin hole 516 is provided at the center of the hitch portion 51 in the left-right direction.

The support portion 52 is, for example, a single member formed by processing and welding a metal member such as a sheet metal. Note that the formation method and shape of the support portion 52 may be changed as appropriate. The support portion 52 may have a configuration in which a plurality of members are connected using a connecting tool such as a screw. As shown in FIGS. 4 and 5, the support portion 52 has a support portion base plate 521 in the shape of a rectangular flat plate that extends in the front-rear and left-right directions. The support portion 52 includes a pair of flat support vertical plates 522L and 522R that are arranged on the left and right sides of the support base plate 521 and extend vertically. The pair of support vertical plates 522L and 522R have the same shape.

Note that most of the pair of vertical support plates 522L and 522R are located above the support base plate 521. Further, the support portion 52 includes a flat support portion reinforcing plate 523 inside the pair of support portion vertical plates 522L and 522R in the left-right direction, but the reinforcing plate 523 may or may not be present.

The support base plate 521 is provided with at least one bolt hole BH that penetrates in the vertical direction and allows the bolt BT to pass therethrough.

Each of the pair of support vertical plates 522L and 522R has a plurality of support adjustment holes 525 passing through in the left-right direction. The plurality of support part adjustment holes 525 have the same shape and the same size. The support part adjustment hole 525 has a circular shape when viewed from the left and right in a plan view. 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 arranged at the rear of the plate. Between the left and right support vertical plates 522L, 522R, the positions where the plurality of adjustment holes 525 are provided in the longitudinal direction and the vertical direction are the same. That is, when the left and right support part vertical plates 522L and 522R are stacked in the left and right direction, the left and right support part adjustment holes 525 overlap in the left and right direction.

Further, each of the pair of vertical supporting portion plates 522L and 522R is provided with at least one bolt hole BH in the front portion that penetrates in the left-right direction and through which the bolt BT is passed. In addition, each of the left and right support vertical plates 522L, 522R is provided with at least one bolt notch BN that is recessed rearward from the front end and through which the bolt BT is passed. Note that it is not necessary to provide both the bolt hole BH and the bolt notch BN, and a configuration may be adopted in which only one of them is provided.

As shown in FIG. 3, the support portion 52 is attached to the mission case 9. Specifically, the support base plate 521 is attached to the lower surface of the mission case 9 with bolts BT. Further, the left and right support vertical plates 522L and 522R are attached to the left and right surfaces of the mission case 9 with bolts BT.

The hitch portion 51 is connected to the support portion 52 using a first connection pin 55, as shown in FIGS. 3 and 4. In this embodiment, the number of first connecting pins 55 is plural (more specifically, two). In detail, first, on both left and right sides, the hitch part adjustment hole 515 provided in the hitch part front vertical plates 512L, 512R and the support part adjustment hole 525 provided in the support part vertical plates 522L, 522R overlap in the left and right direction. It will be done. Then, the first connecting pin 55 is inserted into the adjustment holes 515 and 525 stacked in the left-right direction. Thereby, the hitch part 51 is connected to the support part 52. Note that the first connecting pin 55 is provided with a retainer, and the hitch portion 51 and the support portion 52 can be fixed by inserting the pin into the adjustment hole. In place of the pin member, the hitch portion 51 and the support portion 52 may be fixed using other fasteners such as bolts.

In this embodiment, the number of hitch part adjustment holes 515 provided in each of the left and right hitch part front vertical plates 512L, 512R, and the number of support part adjustment holes 525 provided in each of left and right support part vertical plates 522L, 522R are explained. Both are plural. For this reason, the height of the hitch part 51 can be adjusted by selecting the combination of the hitch part adjustment hole 515 and the support part adjustment hole 525 which are arranged in the vertical direction. That is, the work vehicle 1 is provided with a height adjustment mechanism 57 that allows adjustment of the height at which the hitch portion 51 is supported by the support portion 52. Since the support height of the hitch portion 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.

In this embodiment, the height adjustment mechanism 57 is located in front of the rear end of the PTO shaft 11, as shown in FIG. That is, the support portion 52 supports the hitch portion 51 on the front side of the rear end of the PTO shaft 11 . According to this, the distance L between the rear axle 10 and the load position when the towed object 100 is connected can be shortened. For this reason, it is possible to eliminate or reduce the weight placed on the work vehicle 1 in order to ensure front-rear balance. In this embodiment, the support portion 52 supports the hitch portion 51 in front of the rear end 25a of the draft mechanism 25.

In this embodiment, the number of hitch part adjustment holes 515 provided on each of the left and right sides of the hitch part 51 and the number of support part adjustment holes 525 provided on each left and right side of the support part 52 are both plural. However, this is just an example. For example, either one of the number of hitch adjustment holes 515 provided on each of the left and right sides of the hitch part 51 and the number of support part adjustment holes 525 provided on each of the left and right sides of the support part 52 may be singular. Even in this case, the height of the hitch portion 51 can be adjusted. That is, the work vehicle 1 can be configured to include a height adjustment mechanism.

Further, the number of hitch adjustment holes 515 provided on each of the right and left sides of the hitch portion 51 and the number of support portion adjustment holes 525 provided on each of the left and right sides of the support portion 52 may both be singular. In this case, the working vehicle 1 is not provided with a height adjustment mechanism. However, even in this case, since the support part 52 is configured to support the hitch part 51 in front of the rear end 11a of the PTO shaft 11, the distance L between the rear axle 10 and the load position (see FIG. 3) is Can be shortened. As a result, the towed object 100 that is heavy can be easily handled, and the types of towed objects that can be towed can be increased as much as possible.

When the towed object 100 is towed by the hitch portion 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 traction member 53 whose front end is disposed between the upper and lower hitch rear horizontal plates 513U and 513L. Thereby, the towed object 100 is connected to the hitch portion 51 via the traction member 53. Note that the towing section 50A of this embodiment is suitable for a configuration in which the towed object 100 is towed below the PTO shaft 11. The towed object 100 having such a configuration may include, for example, a trailer.

[2-2. Second embodiment]
FIG. 6 is a side view showing the general configuration of the traction portion 50B and its surroundings in the second embodiment. FIG. 6 also shows a towed object 100 arranged at the rear of the vehicle body 2. As shown in FIG. As shown in FIG. 6, the towing section 50B includes a hitch section 61 and a support section 62. The functions of the hitch part 61 and the support part 62 of this embodiment have many points that overlap with the functions of the hitch part 51 and the support part 52 of the first embodiment. Descriptions of duplicate content will be omitted as appropriate.

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

The support portion 62 is attached to the mission case 9 and supports the hitch portion 61. In this embodiment, the rear end 62a of the support portion 62 is located further back than the rear end 11a of the PTO shaft 11. Further, the rear end 62a of the support portion 62 is provided rearward than the rear end of the top link attachment portion 21 (that is, the rear end 25a of the draft mechanism 25). With such a configuration, the hitch portion 61 can be attached to the support portion 62 while avoiding contact with the draft mechanism 25 at a height position where the draft mechanism 25 is provided.

FIG. 7 is an exploded perspective view showing the general configuration of the traction section 50B of the second embodiment. Note that in FIG. 7, the first connecting pin 65 (see FIG. 6) for connecting the hitch portion 61 and the support portion 62 is omitted. Further, in FIG. 7, the second connecting pin 66 (see FIG. 6) that connects the hitch portion 61 and the traction member 63 is omitted.

The hitch portion 61 is, for example, a single member formed by processing and welding a metal member such as a sheet metal. Note that the formation method and shape of the hitch portion 61 may be changed as appropriate. The support portion 62 may have a configuration in which a plurality of members are connected using a connecting tool such as a screw. As shown in FIG. 7, the hitch portion 61 has a rectangular flat hitch portion base plate 611 that extends in the vertical and horizontal directions. A hitch adjustment hole 612 extending in the left-right direction is provided on the left and right side surfaces of the hitch base plate 611.

The hitch portion 61 also includes a pair of hitch portion rear horizontal plates 613U and 613L that extend rearward from the upper and lower ends of the rear surface of the hitch portion base plate 611. The pair of hitch rear horizontal plates 613U and 613L are vertically spaced apart from each other. The pair of hitch portion rear horizontal plates 613U and 613L have the same shape. The pair of hitch portion rear horizontal plates 613U and 613L extend in the front-rear and left-right directions.

Each of the pair of hitch portion rear horizontal plates 613U and 613L has a connecting pin hole 614 that penetrates in the vertical direction. The connecting pin holes 614 provided in each hitch portion rear horizontal plate 613U, 613L have the same shape and size. The connecting pin hole 614 has a circular shape when viewed from above and below. Between the upper and lower hitch portion rear horizontal plates 613U and 613L, the positions in the front-rear direction and left-right direction where the connecting pin holes 614 are provided are the same. That is, when the upper and lower hitch portion rear horizontal plates 613U and 613L are stacked in the vertical direction, the upper and lower connecting pin holes 614 overlap in the vertical direction. Specifically, the connecting pin hole 614 is provided at the center of the hitch portion 61 in the left-right direction.

The hitch part 61 also has a pair of flat hitch part reinforcing plates 615L and 615R on the rear side of the hitch part base plate 611, which connect the left ends and right ends of the pair of hitch part rear horizontal plates 613U and 613L, respectively. . The pair of hitch portion reinforcing plates 615L and 615R have the same shape. The pair of hitch portion reinforcing plates 615L and 615R extend in the front-rear and up-down directions.

The support portion 62 is, for example, a single member formed by processing and welding a metal member such as a sheet metal. Note that the formation method and shape of the support portion 62 may be changed as appropriate. Further, the support portion 62 may have a configuration in which a plurality of members are connected using a connecting tool such as a screw.

As shown in FIG. 7, the support portion 62 has a support lower base plate 621 in the shape of a rectangular flat plate that extends in the front-rear and left-right directions. Further, the support portion 62 has a support portion upper base plate 622 in the shape of a rectangular flat plate extending in the front-rear and left-right directions above the support lower base plate 621 .

Further, the support section 62 includes a pair of vertical support section plates 623L and 623R arranged on the left and right sides of two base plates 621 and 622 that are vertically spaced apart and extend vertically. A pair of support vertical plates 623L and 623R connect two base plates 621 and 622. The pair of support vertical plates 623L and 623R have the same shape. Note that the pair of support vertical plates 623L and 623R protrude below the support lower base plate 621. Further, the pair of support vertical plates 623L and 623R protrude upward from the support upper base plate 622.

Further, the support section 62 has a pair of left and right support columns 624L and 624R arranged at the rear ends of the pair of support section vertical plates 623L and 623R, respectively. Each of the left and right support columns 624L, 624R extends in the vertical direction and is arranged over a range from the lower end to the upper end of the left and right support vertical plates 623L, 623R. Each of the pair of support columns 624L, 624R is provided with a groove 628 recessed outward in the left-right direction on the inner surface in the left-right direction. A groove 628 provided in each of the left and right support columns 624L and 624R extends from the lower end to the upper end of the support support.

The lower support base plate 621 is provided with at least one bolt hole BH that penetrates in the vertical direction and allows the bolt BT to pass therethrough. Furthermore, a flat support fixing plate 626 is provided on the upper surface of the support part upper base plate 622 and extends in directions parallel to the left-right and up-down directions. In detail, the support part fixing plate 626 is divided into two parts that are spaced apart from each other on the left and right sides. A cylindrical portion 627 extending toward the front is provided on the front surface of each portion of the support portion fixing plate 626 divided into left and right portions. A bolt BT is passed through the pair of left and right cylindrical portions 627.

Each of the left and right support vertical plates 623L, 623R is provided with at least one bolt hole BH that penetrates in the left-right direction in the front portion and through which a bolt BT is passed. Further, each of the left and right support vertical plates 623L, 623R is provided with at least one bolt notch BN that is recessed rearward from the front end and through which the bolt BT is passed. Note that it is not necessary to provide both the bolt hole BH and the bolt notch BN, and a configuration may be adopted in which only one of them is provided.

Each of the left and right support columns 624L, 624R has a plurality of support adjustment holes 625 that penetrate in the left-right direction. The plurality of support part adjustment holes 625 have the same shape and the same size. The support part adjustment hole 625 has a circular shape when viewed in plan from the left and right directions. 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 plurality of adjustment holes 625 are provided at the same longitudinal and vertical positions between the left and right support columns 624L and 624R. Note that the support part adjustment hole 625 is provided on the bottom surface of the groove part 628.

As shown in FIG. 6, the support portion 62 is attached to members constituting the mission case 9 and the draft mechanism 25. Specifically, the support lower base plate 621 is attached to the lower surface of the mission case 9 with bolts BT. Further, the left and right supporting vertical plates 623L and 623R are attached to the left and right surfaces of the mission case 9 with bolts BT. Further, bolts BT passed through a pair of cylindrical portions 627 provided on the support portion fixing plate 626 are attached to the bracket 26 which is a member constituting the draft mechanism 25. Note that the bracket 26 is a member that swingably supports the top link attachment portion 21.

The hitch part 61 is connected to the support part 62 using a first connection pin 65, as shown in FIG. Specifically, first, the left and right ends of the hitch base plate 611 are fitted into the grooves 628 provided in the left and right support columns 624L and 624R. Then, on both left and right sides, the hitch part adjustment hole 612 provided in the hitch part base plate 611 and the support part adjustment hole 625 provided in the pillar parts 624L and 624R are overlapped in the left and right direction. In this state, the first connecting pin 65 is inserted into the adjustment holes 612 and 625 stacked in the left-right direction. Thereby, the hitch part 61 is connected to the support part 62. Note that the first connecting pin 65 is provided with a retainer, and the hitch portion 61 and the support portion 62 can be fixed by inserting the pin into the adjustment hole. In place of the pin member, the hitch portion 61 and the support portion 62 may be fixed with other fasteners such as bolts.

In this embodiment, the number of hitch part adjustment holes 612 provided on the left and right sides of the hitch part 61 is singular. On the other hand, the number of support adjustment holes 625 provided in each of the left and right support columns 624L and 624R is plural. For this reason, the height of the hitch part 61 can be adjusted by selecting the support part adjustment hole 625 to be combined with the hitch part adjustment hole 612. That is, the work vehicle 1 is provided with a height adjustment mechanism 67 that allows adjustment of the height at which the hitch part 61 is supported by the support part 62. Since the support height of the hitch portion 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.

In this embodiment, as shown in FIG. 6, the height adjustment mechanism 67 is located on the rear side of the rear end 25a of the draft mechanism 25. That is, the support portion 62 supports the hitch portion 61 on the rear side of the draft mechanism 25. According to this, the hitch portion 61 can be placed at a high position while avoiding contact with the draft mechanism 25 provided at the rear upper portion of the work vehicle 1. That is, the range in which the height of the hitch portion 61 can be adjusted can be widened. As a result, it is possible to easily deal with differences in towing height due to differences in the type and size of the towed object 100.

In this embodiment, the number of hitch part adjustment holes 612 provided on each of the left and right sides of the hitch part 61 is singular, and the number of support part adjustment holes 625 provided on each of the left and right sides of the support part 62 is plural. However, this is just an example. For example, the number of hitch part adjustment holes 612 provided on each of the left and right sides of the hitch part 61 and the number of support part adjustment holes 625 provided on each of the left and right sides of the support part 62 may be plural. Moreover, the number of hitch part adjustment holes 612 provided on each of the left and right sides of the hitch part 61 may be plural, and the number of support part adjustment holes 625 provided on each of the left and right sides of the support part 62 may be one. Even in these cases, the height of the hitch portion 61 can be adjusted. That is, the work vehicle 1 can be configured to include a height adjustment mechanism.

Furthermore, the number of hitch adjustment holes 612 provided on each of the right and left sides of the hitch portion 61 and the number of support portion adjustment holes 625 provided on each of the left and right sides of the support portion 62 may both be singular. In this case, the structure is such that no height adjustment mechanism is provided. However, even in this case, since the support part 62 is configured to support the hitch part 61 on the rear side of the rear end 25a of the draft mechanism 25, it is possible to cope with the towed object 100 having a high towing height. .

When the towed object 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 traction member 63 whose front end is disposed between the upper and lower hitch rear horizontal plates 613U and 613L. Thereby, the towed object 100 is connected to the hitch portion 51 via the traction member 63. Note that the towing unit 50B of this embodiment can be applied to a configuration in which the towed object 100 is towed above the PTO shaft 11, as shown in FIG. The towed object 100 having such a configuration may include, for example, a thresholder.

[2-3. Third embodiment]
FIG. 8 is a side view showing a general configuration of a traction portion 50C and its surroundings in the third embodiment. FIG. 8 also shows a towed object 100 arranged at the rear of the vehicle body 2. As shown in FIG. As shown in FIG. 8, the towing section 50C includes a hitch section 71 and a support section 72. The functions of the hitch part 71 and the support part 72 of this embodiment have many points that overlap with the functions of the hitch parts 51 and 61 and the support parts 62 and 72 of the first and second embodiments. Descriptions of duplicate content will be omitted as appropriate.

The hitch portion 71 is connected to the towed object 100 via a towing member 73. In the example shown in FIG. 8, the towed object 100 does not require power transmission. However, even in this embodiment, the towed object 100 may have a configuration that requires power transmission. In this case, as shown in FIG. 11, which will be described later, a configuration may be adopted in which power is transmitted from the PTO shaft 11 via the drive shaft 74.

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

The first support portion 721 is attached to the mission case 9. That is, the first support portion 721 is fixed to the vehicle body 2. The second support part 722 is fixed to the first support part 721. With this configuration, the second support portion 722 can be arranged as necessary. That is, the second support part 722 can be removed if it is not needed.

Note that in this embodiment, the second support portion 722 is fixed to a member that constitutes the draft mechanism 25. The member constituting the draft mechanism 25 may be, for example, the bracket 26 fixed to the case of the lifting unit 16 described above. With such a configuration, the support rigidity of the support portion 72 can be increased.

In this embodiment, the rear end 721a of the first support portion 721 is located further forward than the rear end 11a of the PTO shaft 11. Further, the rear end 722a of the second support portion 722 is provided rearward than the rear end of the top link attachment portion 21 (that is, the rear end 25a of the draft mechanism 25).

FIG. 9 is an exploded schematic perspective view showing a hitch part 71 and a support part 72 that constitute a traction part 50C of the third embodiment. Note that in FIG. 9, the first connecting pin 75 (see FIG. 8) for connecting the hitch portion 71 and the support portion 72 is omitted. Further, in FIG. 9, the second connecting pin 76 (see FIG. 8) that connects the hitch portion 71 and the traction member 73 is omitted. Further, FIG. 10 is an exploded schematic perspective view showing a first support part 721 and a second support part 722 that constitute the support part 72 of the third embodiment.

The structure of the hitch section 71 of the third embodiment is similar to the structure of the hitch section 51 of the first embodiment. For this reason, detailed explanation will be omitted. The hitch portion 71 includes a hitch portion base plate 711, a pair of left and right hitch portion front vertical plates 712L, 712R, an upper and lower pair of hitch portion rear horizontal plates 713U, 713L, and a left and right pair of hitch portion reinforcement plates 714L, 714R. . Each of the pair of hitch section front vertical plates has a plurality of hitch section adjustment holes 715. Each of the pair of hitch rear horizontal plates 713U and 713L has a connecting pin hole 716.

Each of the first support part 721 and the second support part 722 is constructed by processing and welding a metal member such as a sheet metal, for example. Note that the formation method and shape of the first support portion 721 and the second support portion 722 may be changed as appropriate.

The configuration of the first support section 721 is generally similar to the configuration of the support section 52 of the first embodiment. For this reason, detailed explanation will be omitted. The first support portion 721 includes 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 base plate 7211 has bolt holes BH. Each of the pair of first support vertical plates 7212L and 7212R has a plurality of support adjustment holes 725. Each of the left and right first support vertical plates 7212L and 7212R has a bolt hole BH and a bolt notch BN. 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 of the first embodiment. The bolt hole BH for connection with the second support part 722 is provided above the central part in the front-rear direction of the first support part vertical plates 7212L, 7212R.

The second support portion 722 has a second support portion base plate 7221 in the shape of a rectangular flat plate that extends in the left-right and up-down directions. The second support portion 722 includes a pair of second support vertical plates 7222L and 7222R arranged on the left and right sides of the second support base plate 7221 and extending in the front and rear and up and down directions. The pair of second support vertical plates 7222L and 7222R have the same shape. Note that the second support portion 722 includes a flat second support portion reinforcing plate 7223 (see FIG. 10), but the reinforcing plate 7223 may or may not be present.

The second support base plate 7221 has cylindrical portions 7224 extending forward on the left and right sides of its front surface. A bolt BT for attaching to the above-mentioned bracket 26 is passed through the pair of left and right cylindrical portions 7224.

Each of the left and right second support part vertical plates 7222L, 7222R has a plurality of support part adjustment holes 725 penetrating in the left-right direction. The plurality of support part adjustment holes 725 have the same shape and the same size. Note that the plurality of support part adjustment holes 725 provided in the second support part 722 have the same shape and the same size as the plurality of support part adjustment holes 725 provided in the first support part 721. The support part adjustment hole 725 has a circular shape when viewed from the left and right in a plan view.

In each of the left and right second support vertical plates 7222L and 7222R, the plurality of support adjustment holes 725 are arranged at equal intervals in the vertical direction and are arranged at the rear of the plates. Between the left and right second support vertical plates 7222L and 7222R, the positions in the front-back direction and the vertical direction where the plurality of adjustment holes 725 are provided are the same. That is, when the left and right second support part vertical plates 7222L, 7222R are stacked in the left and right direction, the left and right support part adjustment holes 725 overlap in the left and right direction. Each of the left and right second support portion vertical plates 7222L, 7222R is provided with at least one bolt hole BH that penetrates in the left-right direction in the front portion and through which the bolt BT is passed. The bolt hole BH is provided for connection with the first support portion 721.

As shown in FIGS. 8 and 9, the first support part 721 and the second support part 722 are connected using bolts BT, and the first support part 721 and the second support part 722 are integrated into a support part. 72 is obtained. A first support base plate 7211 is attached to the lower surface of the mission case 9 with bolts BT. Further, the left and right first support vertical plates 7212L and 7212R are attached to the left and right surfaces of the mission case 9 with bolts BT. The second support portion 722 is fixed to the bracket 26 by a bolt BT passed through the cylindrical portion 7224.

As in this embodiment, when the bottom, left and right sides, and front of the support part 72 are attached to parts constituting the vehicle body 2, if the support part 72 is a single member, the parts High manufacturing precision will be required. In this regard, in this embodiment, the support section 72 is divided into a first support section 721 and a second support section 722, which are separate members. For this reason, the requirement for precision in component manufacturing can be lowered. That is, according to the configuration of this embodiment, parts management can be facilitated.

The hitch part 71 is connected to the support part 72 using a first connection pin 75, as shown in FIG. In this embodiment, the number of first connecting pins 75 is plural (more specifically, two). In detail, first, on both the left and right sides, the hitch part adjustment hole 715 provided in the hitch part front vertical plates 712L, 712R, and the hitch part adjustment hole 715 provided in the first support part vertical plate 7212L, 7212R or the second support part vertical plate 7222L, 7222R. The support part adjustment holes 725 are overlapped in the left-right direction. Then, the first connecting pin 75 is inserted into the adjustment holes 715 and 725 stacked in the left-right direction. Thereby, the hitch part 71 is connected to the support part 72. Note that the first connecting pin 75 is provided with a retainer, and the hitch portion 71 and the support portion 72 can be fixed by inserting the pin into the adjustment hole. Instead of the pin member, the hitch portion 71 and the support portion 72 may be fixed with other fasteners such as bolts.

In this embodiment, the number of hitch part adjustment holes 715 provided in the hitch part front vertical plates 712L, 712R, the first support part vertical plates 7212L, 7212R and the second support part vertical plates 7222L, 7222R on the left and right sides, respectively. The number of support adjustment holes 725 provided is plural. Therefore, the height of the hitch part 71 can be adjusted by selecting the combination of the hitch part adjustment hole 715 and the support part adjustment hole 725. That is, the work vehicle 1 is provided with a height adjustment mechanism 77 that allows the support height of the hitch portion 71 by the support portion 72 to be adjusted. Since the support height of the hitch portion 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.

In this embodiment, a plurality of support adjustment holes 725 are provided in both the first support vertical plates 7212L, 7212R and the second support vertical plates 7222L, 7222R. For this purpose, a first height adjustment mechanism 771 that allows the support height of the hitch part 71 by the first support part 721 to be adjusted, and a first height adjustment mechanism 771 that allows the support height of the hitch part 71 to be adjusted by the second support part 722 are provided. It can be said that two height adjustment mechanisms 772 are provided.

Note that the height adjustment mechanism 77 may include at least one of a first height adjustment mechanism 771 and a second height adjustment mechanism 772. Alternatively, a configuration may be adopted in which the first support portion 721 and the second support portion 722 are not each provided with a height adjustment mechanism. Even in this case, if the hitch part 71 can be connected to each of the first support part 721 and the second support part 722, the height at which the hitch part 71 is supported by the support part 72 can be adjusted.

Specifically, as shown in FIG. 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 section 721 supports the hitch section 71 on the front side of the PTO shaft 11. Further, the second height adjustment mechanism 772 provided on the second support portion 722 is located above the first support portion 721 and on the rear side of the rear end 25a of the draft mechanism 25. That is, the second support part 722 supports the hitch part 71 above the first support part 721 and on the rear side of the draft mechanism 25.

According to such a configuration, the towed object 100 having a low towing height position can be towed by the first support portion 721. The second support portion 722 can tow the towed object 100 at a high towing height position. That is, according to the configuration of this embodiment, the range in which the height of the hitch portion 71 can be adjusted can be widened. As a result, it is possible to easily deal with differences in towing height due to differences in the type and size of the towed object 100.

Furthermore, in the configuration of this embodiment, by using the first support part 721, the hitch part 71 can be placed as far forward as possible with respect to the towed object 100, which tends to be heavy due to a loaded object such as a trailer. Can be done. In this case, the distance L (see FIG. 8) between the rear axle 10 and the load position can be shortened. As a result, even the towed object 100, which tends to be heavy, can be towed without taking extra measures such as increasing the weight of the work vehicle 1.

FIG. 11 is a diagram illustrating a case where the towed object 100 is towed at a towing height different from that in FIG. 8. In the example shown in FIG. 8, the hitch part 71 is connected to the first support part 721. Such a configuration is suitable for a towed object in which the height position at which the towed object 100 is towed by the traction member 73 is below the PTO shaft 11 . In the example shown in FIG. 11, the hitch part 71 is connected to the second support part 722. Such a configuration is suitable for a towed object in which the height position at which the towed object 100 is towed by the traction member 73 is above the PTO shaft 11 .

<3. Things to keep in mind>
Various changes can be made to the various technical features disclosed in this specification without departing from the spirit of the technical creation. Furthermore, the plurality of embodiments and modifications shown in this specification may be implemented in combination to the extent possible.

DESCRIPTION OF SYMBOLS 1... Work vehicle 2... Vehicle body 11... PTO axis 16... Lifting unit 25... Draft mechanism 26... Bracket (member which comprises a draft mechanism)
51, 61, 71... Hitch part 52, 62, 72... Support part 57, 67, 77... Height adjustment mechanism 100... Towed object 721... First support part 721... -Second support part 771...First height adjustment mechanism 772...Second height adjustment mechanism

Claims (7)

A work vehicle capable of towing a towed object disposed at the rear of the vehicle body,
a hitch portion connected to the towed object;
a support part attached to the vehicle body and supporting the hitch part;
Equipped with
A work vehicle provided with a height adjustment mechanism that makes it possible to adjust the height at which the hitch section is supported by the support section. A PTO shaft that can transmit power from an engine mounted on the vehicle body to the outside of the vehicle body,
The work vehicle according to claim 1, wherein the support section supports the hitch section on the front side of the rear end of the PTO shaft. a lifting unit mounted on the vehicle body;
a draft mechanism that adjusts a traction load for towing a working device disposed at the rear of the vehicle body that can be raised and lowered by the lifting unit;
Equipped with
The work vehicle according to claim 1 or 2, wherein the support section supports the hitch section at a rear side of the draft mechanism. a PTO shaft capable of transmitting power from an engine mounted on the vehicle body to the outside of the vehicle body;
a lifting unit mounted on the vehicle body;
a draft mechanism that adjusts a traction load for towing a working device disposed at the rear of the vehicle body that can be raised and lowered by the lifting unit;
Equipped with
The support part is
a first support part that supports the hitch part on the front side of the rear end of the PTO shaft;
a second support part that supports the hitch part above the first support part and on the rear side of the draft mechanism;
The work vehicle according to claim 1, comprising: The height adjustment mechanism is
a first height adjustment mechanism that makes it possible to adjust the height of support of the hitch part by the first support part;
a second height adjustment mechanism that makes it possible to adjust the height of support of the hitch part by the second support part;
The work vehicle according to claim 4, comprising at least one of the following. The first support part and the second support part are constituted by separate members,
the first support part is fixed to the vehicle body,
The work vehicle according to claim 4 or 5, wherein the second support part is fixed to the first support part. The work vehicle according to claim 6, wherein the second support portion is fixed to a member constituting the draft mechanism.