Work vehicle

Abstract

To solve the problem that, when a normal type working machine is mounted on a working vehicle having a high vehicle height, a mounting position becomes higher than usual, and an angle or the like at the time of grounding is different, so that a dedicated working machine is required.SOLUTION: A work vehicle includes a traveling vehicle body, a transmission case configured to transmit a driving force, and a drive shaft configured to transmit the driving force to a work machine attached to a rear portion of the traveling vehicle body, wherein the drive shaft has a rear end extended rearward via a joint member, and a vertical position changing mechanism capable of outputting the driving force from a position lower than an input position to the work machine attached to the rear portion is provided behind the rear end.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle having a work implement attached to the rear of its traveling body. [Background technology]

[0002] A known work vehicle has power transmitted downward from the transmission case, has a lower axle, and is fitted with large-diameter tires to increase ground clearance and enable it to travel over grown crops (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-94775 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when attaching a normal type of work machine to a work vehicle such as the one described above, the attachment position is higher than normal, which causes problems such as different angles when the machine touches the ground, so a dedicated work machine was required.

[0005] For example, as shown in FIG. 20, when the vehicle height of the traveling vehicle body 100 is high, the lower end of the work machine R cannot be lowered sufficiently even if the work machine R is lowered to the maximum extent.

[0006] The present invention aims to provide a work vehicle that can be fitted with a normal type of work implement used in a normal work vehicle that does not have a high ground clearance and can be used for work, even when the work vehicle has a high ground clearance. [Means for solving the problem]

[0007] The first aspect of the present invention is A running vehicle body, a transmission case that transmits driving force; A work vehicle equipped with a drive shaft that transmits driving force to a work implement attached to the rear of the traveling vehicle body, The drive shaft has a rear end that extends rearward via a joint member, A driving force is applied to the rear end. This work vehicle is characterized by being equipped with a vertical position conversion mechanism that can output from a position lower than the input position to a work machine attached to the rear. [Effects of the Invention]

[0008] According to the present invention, a general-purpose work machine, not a dedicated one, can be mounted on a work vehicle with a high ground clearance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an overall side view of a work vehicle according to an embodiment of the present invention to which a work implement is coupled; [Figure 2] FIG. 10 is a side view showing the main parts, focusing on the connecting portion between the work vehicle and the work implement. [Figure 3] Illustration of Figure 2 [Figure 4] A side view of the mounting hitch of the work vehicle [Figure 5] A side view of the intermediate hitch of the work vehicle. [Figure 6] (A), (B), and (C) are side views showing the universal joint of the work vehicle, the vertical position conversion mechanism of the intermediate hitch, and the drive shaft of the work implement. [Figure 7] An exploded side view of the attachment hitch, intermediate hitch, and work equipment of the work vehicle. [Figure 8] An explanatory diagram of how to use the lever member for connecting the work vehicle [Figure 9] FIG. 10 is a side view of the work vehicle in which the intermediate hitch is fixed to the attachment hitch in advance. [Figure 10] Enlarged side view of the main part of Figure 9 [Figure 11] FIG. 10 is a side view of the work vehicle in which the intermediate hitch is fixed to the work implement in advance. [Figure 12] Enlarged side view of the main part of Figure 11 [Figure 13]FIG. 10 is an explanatory perspective view of one-touch mounting in the work vehicle; [Figure 14] (A) and (B) Side views to explain the effectiveness of the work vehicle [Figure 15] (A) and (B) Side views to explain the effectiveness of the work vehicle [Figure 16] A side view illustrating the size of the intermediate hitch of the work vehicle, such as changing the up and down position. [Figure 17] FIG. 10 is a side view illustrating the design dimensions of the intermediate hitch of the work vehicle. [Figure 18] FIG. 10 is a side view illustrating another embodiment of the present invention. [Figure 19] Enlarged view of Figure 18 [Figure 20] A side view showing the conventional tractor and implement connected together DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 1, 2, and 3 show a tractor as an example of a work vehicle according to an embodiment of the present invention. Hereinafter, terms such as front / rear, left / right, and up / down are defined based on the direction of travel of the tractor. As shown in FIGS. 1, 2, and 3, an engine is mounted inside the hood at the front of a traveling body 1 of a work vehicle according to an embodiment of the present invention, and rotational power of this engine is transmitted to a transmission in a transmission case 2, and the rotational power is reduced by this transmission and transmitted to front wheels 3 and rear wheels 4.

[0011] Furthermore, a hydraulic cylinder case is provided above the transmission case 2, and a lift arm 5 is pivotally attached to this hydraulic cylinder case. When hydraulic oil is supplied to the hydraulic lift cylinder in the hydraulic cylinder case, the lift arm 5 rotates upward, and when oil is discharged, the lift arm 5 descends.

[0012] A lifting link mechanism H having a top link 7 and a lower link 8, which is raised and lowered by a lift arm 5 and a lift rod 6, is installed at the rear of the traveling vehicle body 1. Furthermore, an attachment hitch 9 is attached to the rear of the top link 7 and the lower link 8. An intermediate hitch 10 is attached to the rear of this attachment hitch 9. Furthermore, a work machine R is connected to the rear of the intermediate hitch 10.

[0013] A drive shaft 11 of the traveling vehicle body 1 is extended rearward via a joint member, and a rear end 11a of the drive shaft 11 is connected to the lower end of the mounting hitch 9.

[0014] This mounting hitch 9 is not a dedicated mounting hitch for a vehicle height type work vehicle, but may have the same specifications as a mounting hitch for a standard type work vehicle.

[0015] Fig. 4 shows the traveling body 1 and the attachment hitch 9, Fig. 5 shows the intermediate hitch 10, Figs. 6(A), (B), and (C) show a portion of the attachment hitch 9, the intermediate hitch 10, and a portion of the work implement R, and Fig. 7 shows the traveling body 1, lifting link mechanism H, attachment hitch 9, intermediate hitch 10, and work implement R disassembled in the front-to-rear direction. In this case, it is desirable that the attachment hitch 9 have the same configuration as the standard model. This will result in a work vehicle with high compatibility.

[0016] 1 to 7, the rear end 7a of the top link 7 and the upper end 9a of the attachment hitch 9 are rotatably connected. The rear end 8a of the lower link 8 and the shaft 9b at the lower end of the attachment hitch 9 are also rotatably connected. Furthermore, a universal joint 9c as shown in Figure 6(A) is built into the lower end of the attachment hitch 9, and the rear end 11a of the drive shaft 11 is connected to this universal joint 9c.

[0017] Furthermore, a connecting lever member 9e is provided on the rear side below the mounting hitch 9. The mechanism thereof will be described later.

[0018] The intermediate hitch 10 has a top pin 10b attached to its upper end 10a, which can be engaged with a top hook portion 9d above the attachment hitch 9. Furthermore, as shown in Figures 5 and 6, the intermediate hitch 10 has a vertical position conversion mechanism 10c. As shown in Figure 6(B), this vertical position conversion mechanism 10c has an upper drive shaft 10c1, an upper bevel gear 10c2 attached thereto, a lower bevel gear 10c3 meshed with the upper bevel gear 10c2, and a bearing 10c4 at the center of the lower bevel gear 10c3. This configuration reduces the number of components. It also allows for an optimal posture to be achieved according to the tractor's specifications.

[0019] The upper drive shaft 10c1 is connected to the universal joint 9c of the mounting hitch 9 shown in FIG. 6(A) and is rotatable.

[0020] A top hook 10d is formed on the upper rear side of the intermediate hitch 10. Furthermore, a connecting lever member 10e is provided on the lower rear side of the intermediate hitch 10. The mechanism thereof will be described later.

[0021] A connecting pin 10f is provided on the front side of the intermediate hitch 10 in the longitudinal middle, and is connected to the hook portion 9e1 of the lever member 9e of the attachment hitch 9.

[0022] A top pin R1 is provided on the upper front side of the work implement R and is engaged with the top hook 10d of the intermediate hitch 10. A connecting pin R2 is provided in the vertical middle of the work implement R and is connected to the hook portion 10e1 of the lever member 10e of the intermediate hitch 10. R3 is a drive shaft of the work implement R and is connected to the bearing 10c4 of the intermediate hitch 10.

[0023] Next, the structures of the attachment hitch 9, the lever member 9e of the attachment hitch 9, and the lever member 10e of the intermediate hitch 10 will be described. Because both have the same structure, only the lever member 9e of the attachment hitch 9 in Figure 8 will be described. Figure 8(A) shows the lever 9e2 of the lever member 9e pulled upward, and Figure 8(B) shows the lever 9e2 rotated downward. As shown in Figure 8(A), when the lever 9e2 is pulled upward, the hook portion 9e1 opens. By inserting the connecting pin 10f of the intermediate hitch 10 into the opened 9e1, the intermediate hitch 10 is connected to the attachment hitch 9. Meanwhile, the intermediate hitch 10 can also be connected to the work implement R in a similar manner. In this way, when the work implement R is attached to the intermediate hitch 10, it can be securely fastened by the lever 10e2.

[0024] Normally, as shown in Figures 9 and 10, an intermediate hitch 10 is fixed to the attachment hitch 9 of the traveling vehicle body 1, and the work equipment R is connected as needed. By fixing the intermediate hitch 10 to the attachment hitch 9 in advance in this way, the work equipment R can be attached to the attachment hitch 9 with a single touch.

[0025] Alternatively, as shown in Figures 11 and 12, it is of course possible to fix the intermediate hitch 10 to the work machine R in advance and then connect it to the attachment hitch 9 as needed. In this way, with the intermediate hitch 10 fixed to the work machine R, it can be attached to the attachment hitch 9 of the traveling body 1 with one touch, making it easy to attach and detach. That is, as shown in Figure 13, when attaching with one touch, first the top hook 9d is hooked (see X), and when the work machine R is raised with the top hook 9d hooked, the connecting pin 10f enters the hook portion 9e1 (see Y), completing the one-touch attachment. Z indicates the joint portion, which is a spline fit.

[0026] Figure 14 is a diagram illustrating the advantages of the present invention over the prior art, with (A) showing a conventional tractor. If the implement R is attached directly to the mounting hitch of a high-riding tractor, the top link 7 and lower link 8 must be lengthened in the fore-and-aft direction due to size constraints, or the tiller tines R0 cannot be lowered low. The length from the traveling body 1 to the tiller tines R0 is, for example, 1,075.7 cm.

[0027] In contrast, in the embodiment of the present invention shown in Figure 14(B), by attaching the work implement R via an intermediate hitch 10, the distance from the traveling body 1 to the tiller tines R0 can be shortened to 945.33 cm in order to lower the tiller tines R0 to the same height. In other words, the work implement R can be moved forward, improving the front-to-rear balance.

[0028] 15 is also a diagram for explaining the advantages of the present invention over the prior art, with (A) showing a conventional tractor, and the height position of the drive shaft R3 for inputting driving force of the work implement R can be made approximately the same when attaching the work implement R directly to the mounting hitch of a high-height tractor and when an intermediate hitch 10 is used as in (B) of an embodiment of the present invention. In other words, even when using a standard-specification work implement on a high-height tractor, there is the advantage that work can be carried out in the same posture as when using a standard-specification work implement on a standard-height tractor.

[0029] 16 shows the structure of the intermediate hitch 10 (a view showing the main body of the intermediate hitch 10 and the vertical position conversion mechanism 10c separately), and shows that the vertical drop dimension from the upper drive shaft 10c1 on the input side of the intermediate hitch 10 to the bearing 10c4 on the output side is the same as the vertical drop dimension from the top pin 10b to the top hook 10d of the intermediate hitch 10. In this way, by making the vertical dimension for lowering the driving force in the vertical direction by the intermediate hitch 10 the same as the vertical dimension from the top pin 10b to the top hook 10d of the intermediate hitch 10, the top hook 10d of the standard specification work implement R can be connected as is to the intermediate hitch 10 without changing the height of the top pin R1.

[0030] Figure 17 is a side view of the main body of the intermediate hitch 10, with the attachment hitch 9 side and the work implement R side at the front and rear. In other words, it is a diagram that shows the specifications of the attachment hitch 9 side of the tractor and the specifications of the work implement R side. By combining the specifications of the main body of the intermediate hitch 10 with various specifications on the tractor side and the work implement R side, the work implement R can be attached to tractors with different specifications. For example, it can be attached to tractors with special specifications (high-profile types and low-profile types). This allows for the use of a versatile attachment hitch and work implement.

[0031] FIG. 18 is a side view of a tractor according to another embodiment of the present invention, and FIG. 19 is an enlarged view thereof. In both figures, 10c' is a vertical position conversion mechanism in this embodiment. Also, 1a is a PTO bearing built into the traveling vehicle body 1. As shown in FIGS. 18 and 19, this vertical position conversion mechanism 10c' includes an upper drive shaft 10c1', an upper bevel gear 10c2', a lower bevel gear 10c3' meshed with the upper bevel gear 10c2', and a bearing 10c4' at the center of the lower bevel gear 10c3'. The upper drive shaft 10c1' is connected to the PTO bearing 1a, and receives driving force from the traveling vehicle body 1. The driving force is then transmitted from the upper bevel gear 10c2' to the lower bevel gear 10c3'. The drive shaft R3 of the work implement R is connected to the bearing 10c4' of the lower bevel gear 10c3'.

[0032] Since this up-and-down position conversion mechanism 10c' can be attached as a retrofit, it is possible to interchange the work implement for a tractor with a high ground clearance and the work implement with standard specifications.

Industrial Applicability

[0033] The work vehicle according to the present invention can provide a work vehicle that can be operated by mounting a normal type of work implement used for a normal work vehicle with a not-so-high ground clearance even on a work vehicle with a high ground clearance, and thus is useful for a tractor equipped with a tillage cultivator or the like.

Explanation of Reference Numerals

Claims

1. A running vehicle body, a transmission case that transmits driving force; A work vehicle equipped with a drive shaft that transmits driving force to a work implement attached to the rear of the traveling vehicle body, The drive shaft has a rear end that extends rearward via a joint member, A work vehicle characterized by having a vertical position conversion mechanism behind the rear end that can output driving force to a work implement attached to the rear from a position lower than the position at which the driving force is input.

2. A work vehicle as described in claim 1, wherein the up / down position conversion mechanism transmits power input to an internal upper bevel gear to a lower bevel gear provided below the upper bevel gear and outputs the power.

3. A mounting hitch is provided between the traveling vehicle body and the work machine, The vertical position conversion mechanism is connected to the rear of the rear end via an attachment hitch. The work vehicle according to claim 2.

4. An intermediate hitch is provided between the mounting hitch and the work machine, The intermediate hitch includes a top pin that is a connecting portion on the traveling vehicle body side and a top hook that is a connecting portion on the working machine side, The vertical position conversion mechanism has an output position that is a predetermined width below the input position of the driving force, The top hook is provided below the top pin by a predetermined width, The difference between the top hook and the top pin in vertical position is equal to the difference between the input and output positions of the vertical position conversion mechanism. The work vehicle according to claim 3.

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